JP7675659B2 - Method for manufacturing curable resin film, composite sheet, and semiconductor chip - Google Patents

Description

The present invention relates to a method for manufacturing a curable resin film, a composite sheet, and a semiconductor chip. More specifically, the present invention relates to a curable resin film and a composite sheet including the curable resin film, and a method for manufacturing a semiconductor chip having a cured resin film provided as a protective film by using the same.

In recent years, semiconductor devices have been manufactured using a mounting method known as the face-down method, in which a semiconductor chip having bumps on its circuit surface and a substrate for mounting the semiconductor chip are stacked such that the circuit surface of the semiconductor chip faces the substrate, thereby mounting the semiconductor chip on the substrate.
Incidentally, the semiconductor chips are usually obtained by dividing a semiconductor wafer having bumps on its circuit surface.

A semiconductor wafer having bumps may be provided with a protective film for the purpose of protecting the bonded portion between the bump and the semiconductor wafer (hereinafter also referred to as a "bump neck").
For example, in Patent Documents 1 and 2, a laminate having a supporting substrate, an adhesive layer, and a thermosetting resin layer laminated in this order is pressed and attached, with the thermosetting resin layer as the bonding surface, to a bump-forming surface of a semiconductor wafer having bumps, and then the thermosetting resin layer is heated and cured to form a protective film.

JP 2015-092594 A JP 2012-169484 A

In recent years, as IC-embedded products such as electronic devices have become smaller and thinner, there has been a growing demand for thinner semiconductor chips. However, as the semiconductor chip becomes thinner, the strength of the semiconductor chip decreases. This causes a problem that the semiconductor chip is easily damaged, for example, when the semiconductor chip is transported or when a post-process for packaging the semiconductor chip is carried out.
Therefore, it is conceivable to form a protective film on the bump-forming surface of the semiconductor wafer to protect the bump neck and to improve the strength of the semiconductor chip. However, simply forming a protective film on the bump-forming surface of the semiconductor wafer is not sufficient to improve the strength of the semiconductor chip. In addition, the protective film may peel off.

The inventors therefore came up with the idea that by providing a protective film for the purpose of protecting the bump necks not only on the bump-forming surface of the semiconductor chip but also on its side surfaces, it would be possible to improve the strength of the semiconductor chip and inhibit peeling of the protective film, thereby constructing an extremely rational configuration. Based on this idea, the inventors conducted extensive research and have created a curable resin film that can form a protective film with excellent coverage on both the bump-forming surface and side surfaces of a semiconductor chip.

Therefore, the object of the present invention is to provide a curable resin film capable of forming a protective film with excellent covering properties on both the bump-forming surface and the side surfaces of a semiconductor chip, a composite sheet comprising said curable resin film, and a method for manufacturing a semiconductor chip utilizing these (the curable resin film and the composite sheet).

As a result of extensive research, the inventors discovered that the above-mentioned problems could be solved by focusing on parameters calculated from specific physical property values of the curable resin film, and thus completed the present invention.

That is, the present invention relates to the following [1] to [14].
[1] A curable resin film used for forming a cured resin film as a protective film on both a bump-forming surface and a side surface of a semiconductor chip having bumps on the bump-forming surface, the curable resin film satisfying the following requirement (I):
<Requirement (I)>
A strain is generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage modulus of the test piece is measured. When the storage modulus of the test piece when the strain of the test piece is 1% is defined as Gc1 and the storage modulus of the test piece when the strain of the test piece is 300% is defined as Gc300, the X value calculated by the following formula (i) is 19 or more and less than 10,000.
X=Gc1/Gc300...(i)
[2] The curable resin film according to the above-mentioned [1], wherein, in the requirement (I), Gc300 is less than 15,000.
[3] A method for forming a cured resin film as a protective film on both a bump-forming surface and a side surface of a semiconductor chip having bumps,
The support sheet and the curable resin layer are laminated to form a laminate structure.
The curable resin is the curable resin film according to the above [1] or [2].
[4] A method for using the curable resin film according to [1] or [2] above to form a cured resin film as a protective film on both a bump-forming surface and a side surface of a semiconductor chip having bumps.
[5] A method of using the composite sheet according to the above [3] for forming a cured resin film as a protective film on both the bump-forming surface and side surfaces of a semiconductor chip having a bump-forming surface with bumps.
[6] A method for manufacturing a semiconductor chip, comprising the steps of:
The method includes the following steps (S1) to (S4) in this order:
Step (S1): A step of preparing a semiconductor chip fabrication wafer having a bump-forming surface provided with bumps, the bump-forming surface of the semiconductor wafer being provided with grooves as planned division lines formed on the bump-forming surface without reaching the rear surface. Step (S2): A step of pressing and attaching a first curable resin (x1) to the bump-forming surface of the semiconductor chip fabrication wafer, covering the bump-forming surface of the semiconductor chip fabrication wafer with the first curable resin (x1), and embedding the first curable resin (x1) in the grooves formed in the semiconductor chip fabrication wafer. Step (S3): A step of curing the first curable resin (x1) to obtain a semiconductor chip fabrication wafer with a first cured resin film (r1). Step (S4): A step of dividing the semiconductor chip fabrication wafer with the first cured resin film (r1) along the planned division lines to obtain semiconductor chips in which at least the bump-forming surface and side surfaces are covered with the first cured resin film (r1). The method further comprises the following step (S-BG) after the step (S2) and before the step (S3), after the step (S3) and before the step (S4), or in the step (S4),
- Step (S-BG): A step of grinding the back surface of the semiconductor chip production wafer. A method for producing a semiconductor chip, using the curable resin film described in the above [1] or [2] as the first curable resin (x1).
[7] The method for producing a semiconductor chip according to the above [6], wherein the step (S2) is performed by pressing and attaching a first composite sheet (α1) having a laminated structure in which a first support sheet (Y1) and a layer (X1) of the first curable resin (x1) are laminated to the bump formation surface of the semiconductor chip production wafer, using the layer (X1) as an attachment surface.
[8] The method includes the step (S-BG) after the step (S2) and before the step (S3),
The step (S-BG) is carried out by grinding the back surface of the semiconductor chip production wafer with the first composite sheet (α1) attached, and then peeling the first support sheet (Y1) from the first composite sheet (α1),
The method for manufacturing a semiconductor chip described in [7] above, wherein the step (S4) is performed by cutting the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer with the first cured resin film (r1) that is formed in the groove portion along the planned division line.
[9] The step (S-BG) is included after the step (S3) and before the step (S4),
The step (S3) is carried out without peeling the first support sheet (Y1) from the first composite sheet (α1);
The step (S-BG) is carried out by grinding the back surface of the semiconductor chip production wafer with the first composite sheet (α1) attached, and then peeling the first support sheet (Y1) from the first composite sheet (α1),
The method for manufacturing a semiconductor chip described in [7] above, wherein the step (S4) is performed by cutting the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer with the first cured resin film (r1) that is formed in the groove portion along the planned division line.
[10] The method includes the step (S-BG) after the step (S3) and before the step (S4),
After the step (S2) and before the step (S3), the first support sheet (Y1) is peeled off from the first composite sheet (α1);
The step (S-BG) is carried out by attaching a backgrind sheet (b-BG) to the surface of the first cured resin film (r1) of the semiconductor chip production wafer having the first cured resin film (r1), grinding the back surface of the semiconductor chip production wafer with the backgrind sheet (b-BG) attached, and then peeling off the backgrind sheet (b-BG) from the semiconductor chip production wafer having the first cured resin film (r1);
The method for manufacturing a semiconductor chip described in [7] above, wherein the step (S4) is performed by cutting the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer with the first cured resin film (r1) that is formed in the groove portion along the planned division line.
[11] The process includes the step (S-BG) in the step (S4),
After the step (S2) and before the step (S3), the first support sheet (Y1) is peeled off from the first composite sheet (α1);
The method for producing a semiconductor chip according to the above-mentioned [7], wherein the step (S4) is carried out by making an incision along the planned division line in the portion of the first cured resin film (r1) of the semiconductor chip production wafer with the first cured resin film (r1) formed in the groove portion, or by forming a modified region along the planned division line, and then, as the step (S-BG), attaching a backgrind sheet (b-BG) to the surface of the first cured resin film (r1) of the semiconductor chip production wafer with the first cured resin film (r1), and grinding the back surface of the semiconductor chip production wafer with the backgrind sheet (b-BG) attached.
[12] The method for producing a semiconductor chip according to any one of [6] to [11] above, further comprising the following step (T):
Step (T): forming a second cured resin film (r2) on the back surface of the semiconductor chip production wafer. [13] The method for producing a semiconductor chip according to any one of the above [6] to [12], wherein the width of the groove portion is 10 μm to 2000 μm.
[14] The method for manufacturing a semiconductor chip according to any one of [6] to [13] above, wherein the depth of the groove is 30 μm to 700 μm.

According to the present invention, it is possible to provide a curable resin film capable of forming a protective film with excellent covering properties on both the bump-forming surface and the side surfaces of a semiconductor chip, a composite sheet comprising said curable resin film, and a method for manufacturing a semiconductor chip utilizing these (the curable resin film and the composite sheet).

FIG. 2 is a schematic cross-sectional view of a first curable resin film (x1). 1 is a plan view for illustrating a typical amount of protrusion of a resin film when the planar shape of the resin film is circular. FIG. FIG. 2 is a schematic cross-sectional view showing the configuration of a first composite sheet (α1) used in the manufacturing method of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a specific configuration of a first composite sheet (α1). FIG. 4 is a schematic cross-sectional view showing another example of the specific configuration of the first composite sheet (α1). FIG. 11 is a schematic cross-sectional view showing yet another example of the specific configuration of the first composite sheet (α1). 1 is a schematic diagram showing steps of a method for manufacturing a semiconductor chip according to the present invention. 2 is a top view showing an example of a wafer for manufacturing semiconductor chips prepared in step (S1). FIG. 2 is a schematic cross-sectional view showing an example of a wafer for manufacturing semiconductor chips prepared in step (S1). FIG. FIG. 2 is a diagram showing an outline of step (S2). 1 is a diagram showing an outline of a manufacturing method according to a first embodiment. 5A to 5C are diagrams illustrating an outline of a manufacturing method according to a second embodiment. 13A to 13C are diagrams illustrating an outline of a manufacturing method according to a third embodiment. 13A to 13C are diagrams illustrating an outline of a manufacturing method according to a fourth embodiment. FIG. 2 is a plan view illustrating a laminate including a first thermosetting resin film (x1-1) produced when measuring the amount of protrusion of the first thermosetting resin film (x1-1). 1 is a photograph substituting a drawing showing cross-sectional observation results showing the embedding properties of grooves in Examples 1 and 2 and Comparative Example 1.

In this specification, the term "active ingredient" refers to the components contained in the target composition excluding diluting solvents such as water and organic solvents.
In this specification, the weight average molecular weight and number average molecular weight are polystyrene equivalent values measured by gel permeation chromatography (GPC).
In this specification, the lower limit and upper limit described in stages for the preferred numerical range (e.g., range of content, etc.) can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60."

[Curable resin film (first curable resin film (x1))]
The curable resin film of the present invention is used to form cured resin films as protective films on both the bump-forming surface and side surfaces of a semiconductor chip having a bump-forming surface with bumps, and satisfies the following requirement (I).
<Requirement (I)>
A strain is generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage modulus of the test piece is measured. When the storage modulus of the test piece when the strain of the test piece is 1% is defined as Gc1 and the storage modulus of the test piece when the strain of the test piece is 300% is defined as Gc300, the X value calculated by the following formula (i) is 19 or more and less than 10,000.
X=Gc1/Gc300...(i)

The test piece for measuring the storage elastic modulus is in the form of a film, and its planar shape is circular.
The test piece may be a single layer of the curable resin film having a thickness of 1 mm. However, in terms of ease of preparation, it is preferable that the test piece be a laminated film formed by stacking multiple single layers of the curable resin film having a thickness of less than 1 mm.
The thicknesses of the multiple single-layer curable resin films constituting the laminate film may all be the same, may all be different, or may only be partially the same, but in terms of ease of production, it is preferable that they are all the same.

In this specification, the term "storage modulus of a test specimen" is not limited to Gc1 and Gc300, but means "the storage modulus of a test specimen corresponding to the strain generated in a resin film test specimen having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz."

The curable resin film of one embodiment of the present invention can, for example, be a composite sheet having a laminated structure in which a support sheet and a layer of the curable resin film are laminated together.

In this specification, the curable resin film (curable resin film of the present invention) for forming a cured resin film as a protective film on both the bump formation surface and the side surface of the semiconductor chip is also referred to as a "first curable resin film (x1)" or a "first curable resin (x1)". The cured resin film formed by curing the "first curable resin film (x1)" or the "first curable resin (x1)" is also referred to as a "first cured resin film (r1)". The curable resin film for forming a cured resin film as a protective film on the surface (back surface) opposite to the bump formation surface of the semiconductor chip is also referred to as a "second curable resin film (x2)" or a "second curable resin (x2)". The cured resin film formed by curing the "second cured resin film (x2)" or the "second cured resin (x2)" is also referred to as a "second cured resin film (r2)".
In this specification, the composite sheet for forming the first cured resin film (r1) as a protective film on both the bump formation surface and the side surface of the semiconductor chip is also referred to as the "first composite sheet (α1)." The "first composite sheet (α1)" has a laminated structure in which a "first support sheet (Y1)" and a "layer (X1) of a first cured resin (x1)" are laminated.
The composite sheet for forming the second cured resin film (r2) as a protective film on the back surface of the semiconductor chip is also referred to as the "second composite sheet (α2)". The "second composite sheet (α2)" has a laminated structure in which a "second support sheet (Y2)" and a "layer (X2) of second curable resin (x2)" are laminated.

FIG. 1 shows a schematic cross-sectional view of the first curable resin film (x1).
In addition, the figures used in the following explanation may show key parts enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as the actual ones.

The first curable resin film (x1) shown in FIG. 1 has a first release film 151 on one surface (sometimes referred to as the "first surface" in this specification) x1a, and a second release film 152 on the other surface (sometimes referred to as the "second surface" in this specification) x1b opposite the first surface x1a.
The first curable resin film (x1) having such a configuration is suitable for storage, for example, in a roll form.

The first release film 151 and the second release film 152 may both be of known types.
The first release film 151 and the second release film 152 may be the same as or different from each other. An example of a case in which the first release film 151 and the second release film 152 are different from each other is that the peeling force required to peel them from the first curable resin film (x1) is different.

In the first curable resin film (x1) shown in Figure 1, one of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to the object to be attached. Then, the remaining other of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to the first support sheet (Y1) for constituting the first composite sheet (α1) described later.

Although Figure 1 shows an example in which a release film is provided on both sides (first side x1a, second side x1b) of the first curable resin film (x1), the release film may be provided on only one side of the first curable resin film (x1), i.e., only the first side x1a or only the second side x1b.

The first curable resin film (x1) may be either thermosetting or energy ray curable, or may have both thermosetting and energy ray curable properties.

In this specification, the term "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum. Examples of energy rays include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet ray source. Electron beams can be irradiated by generating them using an electron beam accelerator or the like.
In this specification, the term "energy ray curable" means a property of being cured by irradiation with energy rays, and the term "non-energy ray curable" means a property of not being cured even when irradiated with energy rays.

The first curable resin film (x1) contains a resin component.
The first curable resin film (x1) may or may not contain a component other than the resin component together with the resin component.
Preferred embodiments of the first curable resin film (x1) include, for example, a resin component, a filler, and various additives that do not fall into either of these categories (a resin component and a filler) and have an effect of adjusting the storage modulus of the first curable resin film (x1).

Examples of the additives having the effect of adjusting the storage modulus of the first curable resin film (x1) include rheology control agents (thixotropic agents), surfactants, silicone oils, etc.

The first curable resin film (x1) is soft and is suitable for application to an object having an uneven surface, such as a wafer for producing semiconductor chips, which has a bump-forming surface having bumps and grooves as planned division lines.
In the following description, the "wafer for producing semiconductor chips having a bump-forming surface with bumps and grooves as planned division lines" is also simply referred to as the "wafer for producing semiconductor chips".
The first hardening resin film (x1) is pressed against and attached to the bump-formed surface of the semiconductor chip fabrication wafer, whereby the first hardening resin film (x1) fills the grooves with good embedding properties.
In addition, the first curable resin film (x1) is pressed against the bump-formed surface of the semiconductor chip fabrication wafer and attached, so that the bumps penetrate the first curable resin film (x1) and the tops of the bumps protrude from the first curable resin film (x1). The first curable resin film (x1) then spreads between the bumps so as to cover them, adheres closely to the bump-formed surface, and covers the surfaces of the bumps, particularly the surfaces of the areas in the vicinity of the bump-formed surface, to embed the bases of the bumps. In this state, the first curable resin film (x1) is prevented from remaining in the upper parts including the tops of the bumps. Therefore, the first cured resin film (r1), which is the cured product of the first curable resin film (x1), is naturally prevented from adhering to the upper parts of the bumps. Furthermore, even after the first hardening resin film (x1) is attached to an object to which it is to be attached, the area of the first hardening resin film (x1) at the beginning (before attachment) is likely to be maintained, and the phenomenon in which the area of the first hardening resin film (x1) after attachment is larger than the area of the first hardening resin film (x1) at the beginning (before attachment) (hereinafter also referred to as "protrusion") is suppressed. Therefore, when the first hardening resin film (x1) is attached to the bump formation surface of a semiconductor chip fabrication wafer, defective filling of grooves and bump bases is also suppressed.
Furthermore, in the case where the first curable resin film (x1) is used, when the first curable resin film (x1) and its cured product, the first cured resin film (r1), are provided on the bump-forming surface, unintentional exposure (hereinafter also referred to as "cissing") of areas other than the top of the bumps or areas of the bump-forming surface near the bumps is suppressed.
These effects are achieved when the value of X defined in the above requirement (I) is 19 or more and less than 10,000.

The presence or absence of the first cured resin film (x1) or the first cured resin film (r1) remaining on the upper part of the bump can be confirmed, for example, by observing the upper part of the bump with an optical microscope or a SEM (scanning electron microscope) and obtaining image data.
The presence or absence of protrusion of the first curable resin film (x1) can be observed visually or the like.
Furthermore, the presence or absence of repelling of the first cured resin film (x1) or the first cured resin film (r1) can be confirmed, for example, by observing the bump formation surface with an optical microscope or a SEM (scanning electron microscope) and obtaining image data.

When a resin film such as the first curable resin film (x1) is applied to an object to which the resin film is to be applied and protrudes, the amount of protrusion can be calculated by the following method.
That is, the resin film in a protruding state is viewed from above in a plan view, and the maximum length of a line segment connecting two different points on the circumference of the resin film is calculated. Furthermore, the initial width of the resin film (i.e., before the protrusion occurs) is calculated at a position overlapping with the line segment showing this maximum length. The amount of protrusion of the resin film can then be calculated by subtracting the width of the resin film from the maximum length of the line segment.

FIG. 2 is a plan view for illustrating the amount of protrusion of a resin film when the planar shape of the resin film is circular.
The resin film 101 shown in Fig. 2 is in a state where it protrudes from its original size when attached to an object 102 to be attached. The resin film has the original size indicated by reference numeral 101', and is shown for the sake of convenience in order to make it easier to understand the amount of protrusion. The initial resin film 101' has a circular planar shape here, but the planar shape of the protruding resin film 101 is non-circular. However, this is only an example, and the planar shape of the protruding resin film 101 is not limited to that shown here.

To find the amount of protrusion of the resin film 101, the maximum value of the length _D1 of the line segment connecting a point 1010a on the outer periphery 1010 of the resin film 101 and another point 1010b different from this is found, and further, the value _D0 of the initial width (i.e., before protrusion) of the resin film 101' at the position where the length D1 overlaps with the line segment showing this maximum value is found. The difference ( _D1 - _D0 ) between _D1 and _D0 is the amount of protrusion.
The line segment indicating the maximum value in resin film 101 may pass through the center of a circle in original resin film 101' when viewed in a plane, in which case the width value of original resin film 101' at the position where it overlaps with the line segment indicating the maximum value becomes the diameter of resin film 101'.

Note that, here, we have explained the amount of protrusion of the resin film when the planar shape of the resin film is circular, with reference to the drawings. However, the amount of protrusion of the resin film can also be calculated in a similar manner when the planar shape is other than circular.

When the first curable resin film (x1) is attached to the bump-forming surface of a wafer for manufacturing semiconductor chips, the degree of distortion of the curable resin film is significantly different between a middle stage where the tops of the bumps protrude through the first curable resin film (x1) and the first curable resin film (x1) begins to penetrate into the grooves, and a final stage where the first curable resin film (x1) fills the bases of the bumps and fills the grooves. More specifically, the distortion of the first curable resin film (x1) in the middle stage is small, and the distortion of the first curable resin film (x1) in the final stage is large.
The first curable resin film (x1) employs Gc1 as the storage modulus when the strain is small and Gc300 as the storage modulus when the strain is large, so that Gc1 is high and Gc300 is low, and the X value (=Gc1/Gc300) defined in the above requirement (I) is specified to be 19 or more and less than 10,000, thereby achieving the excellent effects described above.

In terms of making it easier to exhibit the effects of the present invention, the upper limit of the X value of the first curable resin film (x1) specified in the above requirement (I) is preferably 5,000 or less, more preferably 2,000 or less, even more preferably 1,000 or less, still more preferably 500 or less, even more preferably 300 or less, still more preferably 100 or less, and still more preferably 70 or less.
Among the effects of the present invention, from the viewpoint of improving the embeddability into the grooves of the wafer for producing semiconductor chips, the value of X specified in the above requirement (I) is preferably 25 or more, more preferably 30 or more, even more preferably 40 or more, still more preferably 50 or more, and even more preferably 60 or more.

In the first curable resin film (x1), Gc1 is not particularly limited, so long as the X value defined in the above requirement (I) is 19 or more and less than 10,000.
However, from the viewpoint of making it easier to exert the effects of the present invention, Gc1 is preferably 1×10 ⁴ to 1×10 ⁶ Pa, more preferably 3×10 ⁴ to 7×10 ⁵ Pa, and even more preferably 5×10 ⁴ to 5×10 ⁵ Pa.

In the first curable resin film (x1), Gc300 is not particularly limited as long as the X value is 19 or more and less than 10,000.
However, among the effects of the present invention, from the viewpoint of improving the embedding property in the grooves of the wafer for producing semiconductor chips, Gc300 is preferably less than 15,000 Pa, more preferably 10,000 Pa or less, even more preferably 5,000 Pa or less, even more preferably 4,000 Pa or less, and even more preferably 3,500 Pa or less. Also, from the viewpoint of suppressing repelling of the first curable resin film (x1), Gc300 is preferably 100 Pa or more, more preferably 500 Pa or more, and even more preferably 1,000 Pa or more.

In the first curable resin film (x1), it is preferable that, in addition to the X value specified in requirement (I) above, either or both of Gc1 and Gc300 satisfy the above range.

The storage modulus of the first curable resin film (x1) is not limited to Gc1 and Gc300, and can be easily adjusted by adjusting one or both of the types and contents of the components contained in the first curable resin film (x1). To achieve this, one or both of the types and contents of the components contained in the composition for forming the first curable resin film (x1) may be adjusted. For example, when using a first thermosetting resin film-forming composition (x1-1-1) described later, the storage modulus of the first curable resin film (x1) can be easily adjusted by adjusting one or both of the types and contents of the main components contained in the composition, such as the polymer component (A) and the filler (D), and adjusting one or both of the types and contents of one or more additives (I) selected from a rheology control agent, a surfactant, and a silicone oil.
For example, by increasing the content of one or both of the filler (D) and the additive (I) in the first curable resin film (x1) and the composition for forming the first curable resin film, Gc1 can be easily adjusted to a large value, and as a result, the X value can be easily adjusted to a large value.

The first curable resin film (x1) may be composed of one layer (single layer) or may be composed of two or more layers. When the first curable resin film (x1) is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

In this specification, not only in the case of the first curable resin film (x1), "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same", and further, "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

The thickness of the first curable resin film (x1) is preferably 10 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, and even more preferably more than 30 μm, from the viewpoint of improving the coverage on the bump formation surface of the semiconductor wafer for producing semiconductor chips and from the viewpoint of further improving the embedding property into the grooves of the semiconductor wafer for producing semiconductor chips. Also, it is preferably 200 μm or less, more preferably 150 μm or less, even more preferably 130 μm or less, even more preferably 100 μm or less, and even more preferably 80 μm or less.
Here, "the thickness of the layer (X1) of the first curable resin (x1)" means the thickness of the entire layer (X1). For example, the thickness of the layer (X1) consisting of multiple layers means the total thickness of all layers constituting the layer (X1).
Here, the "thickness of the first curable resin film (x1)" means the overall thickness of the first curable resin film (x1). For example, the thickness of the first curable resin film (x1) consisting of multiple layers means the total thickness of all layers constituting the first curable resin film (x1).

<First curable resin film-forming composition>
The first curable resin film (x1) can be formed using a first curable resin film-forming composition containing its constituent materials. For example, the first curable resin film (x1) can be formed by applying the first curable resin film-forming composition to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at room temperature in the first curable resin film-forming composition is usually the same as the ratio of the contents of the components in the first curable resin film (x1). In this specification, "room temperature" means a temperature that is not particularly cooled or heated, that is, an ordinary temperature, and examples thereof include a temperature of 15 to 25°C.

The first thermosetting resin film (x1-1) can be formed using a first thermosetting resin film-forming composition (x1-1-1), and the first energy ray curable resin film (x1-2) can be formed using a first energy ray curable resin film-forming composition (x1-2-1). In this specification, when the first curable resin film (x1) has both thermosetting and energy ray curing properties, and the contribution of the heat curing of the first curable resin film (x1) to the y-first cured resin film (r1) formed by its curing is greater than the contribution of the energy ray curing, the first curable resin film (x1) is treated as being thermosetting. Conversely, when the contribution of the energy ray curing of the first curable resin film (x1) to its curing is greater than the contribution of the heat curing, the first curable resin film (x1) is treated as being energy ray curable.

The first curable resin film-forming composition may be applied by a known method, such as a method using various coaters, such as a spin coater, spray coater, air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Mayer bar coater, or kiss coater.

Regardless of whether the first curable resin film (x1) is heat-curable or energy ray-curable, the drying conditions of the composition for forming a curable resin film are not particularly limited. However, when the first curable resin film-forming composition contains a solvent described below, it is preferable to heat-dry it. And, the composition for forming a curable resin film containing a solvent is preferably heat-dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, it is preferable to heat-dry the first thermosetting resin film-forming composition (x1-1-1) so that the composition itself and the first thermosetting resin film (x1-1) formed from this composition are not thermally cured.

Below, the first thermosetting resin film (x1-1) and the first energy ray-curable resin film (x1-2) are described in further detail.

<First thermosetting resin film (x1-1)>
When the first thermosetting resin film (x1-1) is cured to form the first cured resin film (r1), which is the cured product thereof, the curing conditions are not particularly limited as long as the cured product has a degree of curing that allows the cured product to fully exhibit its functions. The curing conditions may be appropriately selected depending on the type of the first thermosetting resin film (x1-1), the application of the cured product, and the like.
The heating temperature during curing of the first thermosetting resin film (x1-1) is preferably 100 to 200° C., more preferably 110 to 170° C., and particularly preferably 120 to 150° C. The heating time during the thermal curing is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 3 hours.

<First curable resin film-forming composition (x1-1-1)>
The first thermosetting resin film-forming composition (x1-1-1) may, for example, be a first thermosetting resin film-forming composition (x1-1-1) (sometimes simply referred to as “composition (x1-1-1)” in this specification) containing a polymer component (A), a thermosetting component (B), a filler (D), and an additive (I).

(Polymer component (A))
The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility, and the like to the first thermosetting resin film (x1-1). The polymer component (A) has thermoplastic properties and does not have thermosetting properties. In this specification, the polymer compound also includes products of polycondensation reactions.
The polymer component (A) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be only one type, or may be two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Examples of the polymer component (A) include polyvinyl acetal, acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, and the like.
Among these, the polymer component (A) is preferably polyvinyl acetal from the viewpoint of easily adjusting the X value to an appropriate value by adjusting Gc300 to an appropriate value.

The polyvinyl acetal in the polymer component (A) may be any of the known polyvinyl acetals.
Among them, preferred polyvinyl acetals include, for example, polyvinyl formal and polyvinyl butyral, with polyvinyl butyral being more preferred.
Examples of polyvinyl butyral include those having structural units represented by the following formulas (i)-1, (i)-2 and (i)-3.

（式中、ｌ、ｍ及びｎは、それぞれ独立に１以上の整数である。）

(In the formula, l, m, and n are each independently an integer of 1 or more.)

The weight-average molecular weight (Mw) of the polyvinyl acetal is preferably 5,000 to 200,000, and more preferably 8,000 to 100,000. When the weight-average molecular weight of the polyvinyl acetal is in such a range, when the first thermosetting resin film (x1-1) is attached to the bump-forming surface of a semiconductor chip fabrication wafer, the effect of suppressing the first thermosetting resin film (x1-1) remaining on the upper part of the bump, the effect of suppressing the protrusion of the first thermosetting resin film (x1-1), the effect of suppressing the repelling of the first thermosetting resin film (x1-1) and its cured product on the bump-forming surface, and the effect of improving the embeddability of the first thermosetting resin film (x1-1) in the groove are enhanced.

The glass transition temperature (Tg) of the polyvinyl acetal is preferably 40 to 80° C., and more preferably 50 to 70° C. When the Tg of the polyvinyl acetal is in such a range, when the first thermosetting resin film (x1-1) is attached to the bump-forming surface of a wafer for manufacturing semiconductor chips, the effect of suppressing the first thermosetting resin film (x1-1) remaining on the upper part of the bump, the effect of suppressing the protrusion of the first thermosetting resin film (x1-1), the effect of suppressing the repelling of the first thermosetting resin film (x1-1) and its cured product on the bump-forming surface, and the effect of improving the embeddability of the first thermosetting resin film (x1-1) in the groove are enhanced.

The ratio of the three or more monomers that make up the polyvinyl acetal can be selected arbitrarily.

The acrylic resin in the polymer component (A) may be any known acrylic polymer.
The weight-average molecular weight (Mw) of the acrylic resin is preferably 5,000 to 1,000,000, and more preferably 8,000 to 800,000. When the weight-average molecular weight of the acrylic resin is in such a range, when the first thermosetting resin film (x1-1) is attached to the bump-forming surface of the semiconductor chip fabrication wafer, the effect of suppressing the first thermosetting resin film (x1-1) remaining on the upper part of the bump, the effect of suppressing the protrusion of the first thermosetting resin film (x1-1), the effect of suppressing the repelling of the first thermosetting resin film (x1-1) and its cured product on the bump-forming surface, and the effect of improving the embeddability of the first thermosetting resin film (x1-1) in the groove are further enhanced.

The glass transition temperature (Tg) of the acrylic resin is preferably -50 to 70°C, and more preferably -30 to 60°C. When the Tg of the acrylic resin is in this range, when the first thermosetting resin film (x1-1) is attached to the bump-forming surface of a wafer for manufacturing semiconductor chips, the effect of suppressing the first thermosetting resin film (x1-1) remaining on the top of the bumps, the effect of suppressing the protrusion of the first thermosetting resin film (x1-1), the effect of suppressing the repelling of the first thermosetting resin film (x1-1) and its cured product on the bump-forming surface, and the effect of improving the embeddability of the first thermosetting resin film (x1-1) in grooves are enhanced.

When an acrylic resin has two or more structural units, the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula. The Tg of the monomer from which the structural unit is derived can be the value listed in the Polymer Data Handbook or the Adhesive Handbook.

The monomers constituting the acrylic resin may be of only one type or of two or more types, and if there are two or more types, the combination and ratio of these can be selected arbitrarily.

Examples of the acrylic resin include polymers of one or more (meth)acrylic acid esters;
A copolymer of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like;
Examples of the copolymer include copolymers of one or more (meth)acrylic acid esters and one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like.

In this specification, "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid. For example, "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate," and "(meth)acryloyl group" is a concept that includes both "acryloyl group" and "methacryloyl group."

Examples of the (meth)acrylic acid ester constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and p) (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms, such as isononyl acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate);
(meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate;
(Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate;
(Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester;
(meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester;
(Meth)acrylic acid imide;
glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate;
hydroxyl group-containing (meth)acrylic acid esters such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate;
Examples of such esters include (meth)acrylic acid esters containing a substituted amino group, such as N-methylaminoethyl (meth)acrylate. Here, the term "substituted amino group" refers to a group in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

The acrylic resin may have a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group. The functional group of the acrylic resin may bond with other compounds via a crosslinking agent (F) described below, or may bond directly with other compounds without the crosslinking agent (F). When the acrylic resin bonds with other compounds via the functional group, the reliability of the package obtained using the first thermosetting resin film (x1-1), for example, tends to be improved.

In the composition (x1-1-1), the ratio of the content of polymer component (A) to the total content of all components other than the solvent (i.e., the ratio of the content of polymer component (A) in the first thermosetting resin film (x1-1) to the total mass of the first thermosetting resin film (x1-1)) is preferably 5 to 25% by mass, and more preferably 5 to 15% by mass, regardless of the type of polymer component (A).

(Thermosetting component (B))
The thermosetting component (B) has thermosetting properties and is a component for thermally curing the first thermosetting resin film (x1-1) to form a hard cured product.
The thermosetting component (B) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be only one type, or may be two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Examples of the thermosetting component (B) include epoxy-based thermosetting resins, polyimide resins, and unsaturated polyester resins.
Among these, the thermosetting component (B) is preferably an epoxy-based thermosetting resin.

Epoxy-Based Thermosetting Resin The epoxy-based thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2).
The epoxy-based thermosetting resin contained in the composition (x1-1-1) and the first thermosetting resin film may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Epoxy resin (B1)
The epoxy resin (B1) may be any known epoxy resin, such as a polyfunctional epoxy resin, a biphenyl compound, bisphenol A diglycidyl ether and its hydrogenated product, orthocresol novolac epoxy resin, a dicyclopentadiene type epoxy resin, a biphenyl type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a phenylene skeleton type epoxy resin.

The epoxy resin (B1) may be an epoxy resin having an unsaturated hydrocarbon group. An epoxy resin having an unsaturated hydrocarbon group has a higher compatibility with acrylic resin than an epoxy resin not having an unsaturated hydrocarbon group. Therefore, by using an epoxy resin having an unsaturated hydrocarbon group, for example, the reliability of a package obtained using the first thermosetting resin film (x1-1) tends to be improved.

Examples of epoxy resins having an unsaturated hydrocarbon group include compounds obtained by converting a part of the epoxy groups of a polyfunctional epoxy resin into a group having an unsaturated hydrocarbon group. Such compounds can be obtained, for example, by subjecting the epoxy groups to an addition reaction with (meth)acrylic acid or a derivative thereof.
Furthermore, examples of epoxy resins having an unsaturated hydrocarbon group include compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like constituting the epoxy resin.
The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethenyl group (vinyl group), a 2-propenyl group (allyl group), a (meth)acryloyl group, and a (meth)acrylamide group, with an acryloyl group being preferred.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of the curability of the first thermosetting resin film (x1-1) and the strength and heat resistance of the cured product of the first thermosetting resin film (x1-1), it is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000.
The epoxy equivalent of the epoxy resin (B1) is preferably from 100 to 1,000 g/eq, and more preferably from 200 to 800 g/eq.

The epoxy resin (B1) may be used alone or in combination of two or more types. When two or more types are used in combination, the combination and ratio of the resins may be selected arbitrarily.

Heat curing agent (B2)
The heat curing agent (B2) functions as a curing agent for the epoxy resin (B1).
The heat curing agent (B2) may be, for example, a compound having two or more functional groups capable of reacting with an epoxy group in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an anhydride group of an acid group, and the like. The phenolic hydroxyl group, the amino group, or an anhydride group of an acid group is preferable, and the phenolic hydroxyl group or the amino group is more preferable.

Among the heat curing agents (B2), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkylphenolic resins.
Among the heat curing agents (B2), examples of amine-based curing agents having an amino group include dicyandiamide (hereinafter sometimes abbreviated as "DICY").

The heat curing agent (B2) may have an unsaturated hydrocarbon group.
Examples of the heat curing agent (B2) having an unsaturated hydrocarbon group include a compound in which a portion of the hydroxyl groups of a phenol resin is substituted with a group having an unsaturated hydrocarbon group, and a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenol resin.
The unsaturated hydrocarbon group in the heat curing agent (B2) is the same as the unsaturated hydrocarbon group in the above-mentioned epoxy resin having an unsaturated hydrocarbon group.

Of the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resins, novolac-type phenol resins, dicyclopentadiene-type phenol resins, and aralkyl-type phenol resins is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000.
Of the thermosetting agent (B2), the molecular weight of the non-resin components, such as biphenol and dicyandiamide, is not particularly limited, but is preferably, for example, 60 to 500.

The thermosetting agent (B2) may be used alone or in combination of two or more types. When two or more types are used in combination, the combination and ratio of the two or more types can be selected arbitrarily.

In the composition (x1-1-1) and the first thermosetting resin film (x1-1), the content of the thermosetting agent (B2) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, and may be, for example, any of 5 to 150 parts by mass, 10 to 100 parts by mass, and 15 to 75 parts by mass, relative to 100 parts by mass of the epoxy resin (B1). When the content of the thermosetting agent (B2) is equal to or greater than the lower limit, the curing of the first thermosetting resin film (x1-1) is more likely to proceed. When the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the first thermosetting resin film (x1-1) is reduced, and the reliability of the package obtained using the first thermosetting resin film (x1-1) is further improved, for example.

In the composition (x1-1-1) and the first thermosetting resin film (x1-1), the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is preferably 600 to 1000 parts by mass relative to 100 parts by mass of the content of the polymer component (A). By having the content of the thermosetting component (B) in such a range, when the first thermosetting resin film (x1-1) is attached to the bump-forming surface of a semiconductor chip production wafer, the effect of suppressing the remaining of the first thermosetting resin film (x1-1) on the upper part of the bump, the effect of suppressing the protrusion of the first thermosetting resin film (x1-1), the effect of suppressing the repelling of the first thermosetting resin film (x1-1) and its cured product on the bump-forming surface, and the effect of improving the embeddability of the first thermosetting resin film (x1-1) in the groove are enhanced, and a hard cured product can be formed.
Furthermore, in order to obtain such effects more significantly, the content of the thermosetting component (B) may be appropriately adjusted depending on the type of the polymer component (A).

For example, when the polymer component (A) is the polyvinyl acetal, in the composition (x1-1-1) and the first thermosetting resin film (x1-1), the content of the thermosetting component (B) is preferably 600 to 1,000 parts by mass, more preferably 650 to 1,000 parts by mass, and particularly preferably 650 to 950 parts by mass, per 100 parts by mass of the polymer component (A).

(Filler (D))
By adjusting the amount of the filler (D) in the composition (x1-1-1) and the first thermosetting resin film (x1-1), the X value can be adjusted more easily. In addition, by adjusting the amount of the filler (D) in the composition (x1-1-1) and the first thermosetting resin film (x1-1), the thermal expansion coefficient of the cured product of the first thermosetting resin film (x1-1) can be adjusted more easily. For example, by optimizing the thermal expansion coefficient of the cured product of the first thermosetting resin film (x1-1) for the object to which the cured product is formed, the reliability of the package obtained using the first thermosetting resin film (x1-1) is further improved. In addition, by using the first thermosetting resin film (x1-1) containing the filler (D), it is also possible to reduce the moisture absorption rate of the cured product of the first thermosetting resin film (x1-1) or improve the heat dissipation.

The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler.
Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, and the like; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, and the like.
Among these, the inorganic filler is preferably silica or alumina.

The filler (D) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

In the composition (x1-1-1), the ratio of the content of the filler (D) to the total content of all components other than the solvent (i.e., the ratio of the content of the filler (D) in the first thermosetting resin film (x1-1) to the total mass of the first thermosetting resin film (x1-1)) is preferably 5 to 45% by mass, more preferably 5 to 40% by mass, and even more preferably 5 to 30% by mass. When the ratio is in such a range, when the first thermosetting resin film (x1-1) is attached to the bump-forming surface of a wafer for producing semiconductor chips, the effect of suppressing the remaining of the first thermosetting resin film (x1-1) on the upper part of the bump, the effect of suppressing the protrusion of the first thermosetting resin film (x1-1), the effect of suppressing the repelling of the first thermosetting resin film (x1-1) and its cured product on the bump-forming surface, and the effect of improving the embeddability of the first thermosetting resin film (x1-1) in the groove are further enhanced, and the above-mentioned thermal expansion coefficient can be more easily adjusted.

(Additive (I))
By adjusting the type or amount of the additive (I) in the composition (x1-1-1) and the first thermosetting resin film (x1-1), Gc1 can be appropriately adjusted, and the X value can be more easily adjusted.
Among these, examples of the additive (I) that are preferable in terms of making it easier to adjust the X value include rheology control agents, surfactants, silicone oils, and the like.

More specifically, examples of the rheology control agent include polyhydroxycarboxylic acid esters, polyvalent carboxylic acids, and polyamide resins.
Examples of the surfactant include modified siloxane and acrylic polymer.
Examples of the silicone oil include aralkyl-modified silicone oil and modified polydimethylsiloxane, and examples of the modifying group include aralkyl groups; polar groups such as hydroxyl groups; and groups having an unsaturated bond such as vinyl groups and phenyl groups.

In addition to the above, additives (I) may also include various other general-purpose additives such as plasticizers, antistatic agents, antioxidants, gettering agents, ultraviolet absorbers, and tackifiers.

The additive (I) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be only one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

The content of the additive (I) in the composition (x1-1-1) and the first thermosetting resin film (x1-1) is not particularly limited and can be appropriately adjusted depending on the type and purpose.
For example, when the purpose is to adjust the X value, the ratio of the content of the additive (I) to the total content of all components other than the solvent in the composition (x1-1-1) (i.e., the ratio of the content of the additive (I) in the first thermosetting resin film (x1-1) to the total mass of the first thermosetting resin film (x1-1)) is preferably 0.5 to 10 mass%, more preferably 0.5 to 7 mass%, and even more preferably 0.5 to 5 mass%.

(Curing Accelerator (C))
The composition (x1-1-1) and the first thermosetting resin film (x1-1) may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing speed of the composition (x1-1-1).
Preferred examples of the curing accelerator (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

The curing accelerator (C) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

When the curing accelerator (C) is used, the content of the curing accelerator (C) in the composition (x1-1-1) and the first thermosetting resin film (x1-1) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is equal to or greater than the lower limit, the effect of using the curing accelerator (C) is more pronounced. When the content of the curing accelerator (C) is equal to or less than the upper limit, for example, the effect of suppressing the highly polar curing accelerator (C) from migrating to the adhesive interface with the adherend in the first thermosetting resin film (x1-1) under high temperature and high humidity conditions and segregating therein is enhanced, and the reliability of the package obtained using the first thermosetting resin film (x1-1) is further improved.

(Coupling Agent (E))
The composition (x1-1-1) and the first thermosetting resin film (x1-1) may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness and adhesion of the first thermosetting resin film (x1-1) to an adherend can be improved. In addition, by using the coupling agent (E), the water resistance of the cured product of the first thermosetting resin film (x1-1) is improved without impairing the heat resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional groups of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.
Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples of the silane include bis(3-(aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane.

The coupling agent (E) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be only one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

When a coupling agent (E) is used, the content of the coupling agent (E) in the composition (x1-1-1) and the first thermosetting resin film (x1-1) is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). When the content of the coupling agent (E) is equal to or greater than the lower limit, the effects of using the coupling agent (E), such as improved dispersibility of the filler (D) in the resin and improved adhesion of the first thermosetting resin film (x1-1) to the object to which it is applied, are more significantly obtained. When the content of the coupling agent (E) is equal to or less than the upper limit, the generation of outgassing is further suppressed.

(Crosslinking Agent (F))
When the polymer component (A) has a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group, the composition (X1-1-1) and the first thermosetting resin film (x1-1) may contain a crosslinking agent (F). The crosslinking agent (F) is a component for bonding the functional group in the polymer component (A) with other compounds to cause crosslinking, and by crosslinking in this manner, the initial adhesive strength and cohesive strength of the first thermosetting resin film (x1-1) can be adjusted.

Examples of the crosslinking agent (F) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure), aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group), etc.

Examples of the organic polyisocyanate compound include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, and alicyclic polyisocyanate compounds (hereinafter, these compounds may be collectively referred to as "aromatic polyisocyanate compounds, etc."); trimers, isocyanurates, and adducts of the aromatic polyisocyanate compounds; and terminal isocyanate urethane prepolymers obtained by reacting the aromatic polyisocyanate compounds, etc. with polyol compounds. The "adduct" refers to a reaction product of the aromatic polyisocyanate compound, aliphatic polyisocyanate compound, or alicyclic polyisocyanate compound with a low-molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, or castor oil. Examples of the adduct include a xylylene diisocyanate adduct of trimethylolpropane, as described below. Moreover, the term "isocyanate-terminated urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at the terminal of the molecule.

More specifically, examples of the organic polyisocyanate compound include 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; a compound in which one or more of tolylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are added to all or some of the hydroxyl groups of a polyol such as trimethylolpropane; lysine diisocyanate, and the like.

Examples of the organic polyvalent imine compounds include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-β-aziridinyl propionate, N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine, etc.

When an organic polyisocyanate compound is used as the crosslinking agent (F), it is preferable to use a hydroxyl group-containing polymer as the polymer component (A). When the crosslinking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, a crosslinked structure can be easily introduced into the first thermosetting resin film (x1-1) by the reaction between the crosslinking agent (F) and the polymer component (A).

The crosslinking agent (F) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

When a crosslinking agent (F) is used, the content of the crosslinking agent (F) in the composition (x1-1-1) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the content of the polymer component (A). When the content of the crosslinking agent (F) is equal to or greater than the lower limit, the effect of using the crosslinking agent (F) is more pronounced. When the content of the crosslinking agent (F) is equal to or less than the upper limit, excessive use of the crosslinking agent (F) is suppressed.

(Energy Ray Curable Resin (G))
The composition (x1-1-1) and the first thermosetting resin film (x1-1) may contain an energy ray-curable resin (G).
Since the first thermosetting resin film (x1-1) contains the energy ray-curable resin (G), the properties can be changed by irradiation with energy rays.

The energy ray curable resin (G) is obtained by polymerizing (curing) an energy ray curable compound. Examples of the energy ray curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

Examples of acrylate compounds include chain-type acrylates such as trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of the polyalkylene glycol (meth)acrylate include an aliphatic skeleton-containing (meth)acrylate; a cyclic aliphatic skeleton-containing (meth)acrylate such as dicyclopentanyl di(meth)acrylate; a polyalkylene glycol (meth)acrylate such as polyethylene glycol di(meth)acrylate; an oligoester (meth)acrylate; a urethane (meth)acrylate oligomer; an epoxy-modified (meth)acrylate; a polyether (meth)acrylate other than the above-mentioned polyalkylene glycol (meth)acrylates; and an itaconic acid oligomer.

The weight average molecular weight of the energy ray curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

The energy ray curable compound used in the polymerization may be used alone or in combination of two or more. When two or more energy ray curable compounds are used in the polymerization, their combination and ratio can be selected arbitrarily.

When energy ray curable resin (G) is used, the content of energy ray curable resin (G) is preferably 1 to 95 mass%, more preferably 5 to 90 mass%, and even more preferably 10 to 85 mass%, based on the total amount of active ingredients of composition (x1-1-1).

(Photopolymerization Initiator (H))
When the composition (x1-1-1) and the first thermosetting resin film (x1-1) contain an energy ray curable resin (G), in order to efficiently proceed with the polymerization reaction of the energy ray curable resin (G), the composition (x1-1-1) and the first thermosetting resin film (x1-1) may contain a photopolymerization initiator (H).

Examples of photopolymerization initiators (H) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2-chloroanthraquinone.

The photopolymerization initiator (H) may be used alone or in combination of two or more. When two or more types of photopolymerization initiator (H) are used, the combination and ratio thereof may be selected arbitrarily.

In composition (x1-1-1), the content of the photopolymerization initiator (H) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass, per 100 parts by mass of the energy ray-curable resin (G).

(Other ingredients)
The composition (x1-1-1) and the first thermosetting resin film (x1-1) may contain other components that do not fall under any of the above-mentioned polymer component (A), thermosetting component (B), curing accelerator (C), filler (D), coupling agent (E), crosslinking agent (F), energy ray curable resin (G), photopolymerization initiator (H), and additive (I), within a range that does not impair the effects of the present invention.

The other components contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.
The contents of the other components in the composition (x1-1-1) and the first thermosetting resin film (x1-1) are not particularly limited and may be appropriately selected depending on the purpose.

(solvent)
The composition (x1-1-1) preferably further contains a solvent. The composition (x1-1-1) containing a solvent has good handleability.
The solvent is not particularly limited, but preferred examples thereof include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.
The solvent contained in the composition (x1-1-1) may be only one type, or may be two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

A more preferred example of the solvent contained in composition (x1-1-1) is methyl ethyl ketone, etc., which allows the components contained in composition (x1-1-1) to be mixed more uniformly.

The solvent content of composition (x1-1-1) is not particularly limited and may be selected appropriately depending on, for example, the types of components other than the solvent.

<Method for producing first thermosetting resin film-forming composition (x1-1-1)>
The first thermosetting resin film-forming composition (x1-1-1) can be obtained by blending the respective components constituting the first thermosetting resin film.
The order of addition of the components is not particularly limited, and two or more components may be added simultaneously.
The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blade, a method of mixing using a mixer, a method of mixing by applying ultrasound, etc.
The temperature and time during addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. The temperature is preferably 15 to 30°C.

<First energy ray curable resin film (x1-2)>
The curing conditions for curing the first energy ray curable resin film (x1-2) to form the first cured resin film (r1) as a cured product thereof are not particularly limited as long as the cured product has a degree of curing that allows the cured product to fully exhibit its functions. The curing conditions may be appropriately selected depending on the type of the first energy ray curable resin film (x1-2), the application of the cured product, and the like.
For example, the illuminance of the energy rays during curing of the first energy ray-curable resin film (x1-2) is preferably 180 to 280 mW/cm ^2. The amount of energy rays during the curing is preferably 450 to 1000 mJ/cm ² .

<First energy ray curable resin film forming composition (x1-2-1)>
Examples of the first energy ray-curable resin film-forming composition (x1-2-1) include a first energy ray-curable resin film-forming composition (x1-2-1) (sometimes simply referred to as “composition (x1-2-1)” in this specification) containing an energy ray-curable component (a), a filler, and an additive.

(Energy Ray-Curable Component (a))
The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and is also a component that imparts film-forming properties, flexibility, and the like to the first energy ray-curable resin film (x1-2).
The energy ray-curable component (a) is preferably uncured and preferably has adhesive properties, and more preferably is uncured and has adhesive properties.

Examples of the energy ray-curable component (a) include a polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000, and a compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000. The polymer (a1) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

A polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000
Examples of the polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000 include an acrylic resin (a1-1) obtained by polymerizing an acrylic polymer (a11) having a functional group capable of reacting with a group possessed by another compound, and an energy ray-curable compound (a12) having a group reactive with the functional group and an energy ray-curable group such as an energy ray-curable double bond.

Examples of the functional group capable of reacting with a group possessed by another compound include a hydroxyl group, a carboxy group, an amino group, a substituted amino group (a group in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom), an epoxy group, etc. However, from the viewpoint of preventing corrosion of circuits of a semiconductor wafer, a semiconductor chip, etc., it is preferable that the functional group is a group other than a carboxy group.
Of these, the functional group is preferably a hydroxyl group.

Acrylic polymer having a functional group (a11)
The acrylic polymer (a11) having a functional group can be, for example, a polymer obtained by copolymerizing an acrylic monomer having the functional group with an acrylic monomer not having the functional group. In addition to these monomers, the acrylic polymer may also be a polymer obtained by copolymerizing a monomer other than the acrylic monomer (a11) with a non-acrylic monomer.
The acrylic polymer (a11) may be a random copolymer or a block copolymer.

Examples of acrylic monomers having the functional group include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, substituted amino group-containing monomers, and epoxy group-containing monomers.

Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; non-(meth)acrylic unsaturated alcohols (unsaturated alcohols not having a (meth)acryloyl skeleton) such as vinyl alcohol and allyl alcohol.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; anhydrides of the ethylenically unsaturated dicarboxylic acids; and (meth)acrylic acid carboxyalkyl esters such as 2-carboxyethyl methacrylate.

The acrylic monomer having the functional group is preferably a hydroxyl group-containing monomer or a carboxyl group-containing monomer, more preferably a hydroxyl group-containing monomer.

The acrylic monomer having the functional group constituting the acrylic polymer (a11) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Examples of acrylic monomers not having a functional group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and isopropyl (meth)acrylate. Examples of such alkyl (meth)acrylates include (meth)acrylates in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms, such as sononyl, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate).

Examples of acrylic monomers that do not have the functional group include (meth)acrylic acid esters containing an alkoxyalkyl group, such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; (meth)acrylic acid esters having an aromatic group, including (meth)acrylic acid aryl esters such as phenyl (meth)acrylate; non-crosslinkable (meth)acrylamide and derivatives thereof; and (meth)acrylic acid esters having a non-crosslinkable tertiary amino group, such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

The acrylic monomer not having a functional group constituting the acrylic polymer (a11) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; and styrene.
The non-acrylic monomer constituting the acrylic polymer (a11) may be of only one kind or of two or more kinds. When the non-acrylic monomer is of two or more kinds, the combination and ratio thereof can be arbitrarily selected.

In the acrylic polymer (a11), the ratio (content) of the amount of the structural unit derived from the acrylic monomer having the functional group to the total amount of the structural units constituting the acrylic polymer (a11) is preferably 0.1 to 50 mass%, more preferably 1 to 40 mass%, and particularly preferably 3 to 30 mass%. When the ratio is in such a range, the content of the energy ray curable group in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy ray curable compound (a12) makes it possible to easily adjust the degree of curing of the cured product of the first energy ray curable resin film (x1-2) to a preferred range.

The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be of only one type or of two or more types, and if it is of two or more types, the combination and ratio thereof can be selected arbitrarily.

In composition (x1-2-1), the ratio of the content of acrylic resin (a1-1) to the total content of components other than the solvent (i.e., the ratio of the content of acrylic resin (a1-1) in the first energy ray-curable resin film (x1-2) to the total mass of the film) is preferably 1 to 40 mass%, more preferably 2 to 30 mass%, and particularly preferably 3 to 20 mass%.

Energy ray curable compound (a12)
The energy ray curable compound (a12) preferably has one or more groups selected from the group consisting of an isocyanate group, an epoxy group, and a carboxy group as a group capable of reacting with the functional group of the acrylic polymer (a11), and more preferably has an isocyanate group as the group. For example, when the energy ray curable compound (a12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

The energy ray curable compound (a12) preferably has 1 to 5 energy ray curable groups in one molecule, and more preferably has 1 to 2 energy ray curable groups.

Examples of the energy ray-curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate;
an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate;
Examples of the isocyanate include an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate.
Among these, the energy ray curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

The energy ray curable compound (a12) constituting the acrylic resin (a1-1) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

In the acrylic resin (a1-1), the ratio of the content of the energy ray curable group derived from the energy ray curable compound (a12) to the content of the functional group derived from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. When the content ratio is in such a range, the adhesive strength of the cured product of the energy ray curable resin film (x1-2) becomes greater. In addition, when the energy ray curable compound (a12) is a monofunctional compound (having one of the groups in one molecule), the upper limit of the content ratio is 100 mol%, but when the energy ray curable compound (a12) is a polyfunctional compound (having two or more of the groups in one molecule), the upper limit of the content ratio may exceed 100 mol%.

The weight average molecular weight (Mw) of the polymer (a1) is preferably 100,000 to 2,000,000, and more preferably 300,000 to 1,500,000.

When the polymer (a1) is at least partially crosslinked by a crosslinking agent, the polymer (a1) may be crosslinked at the group reactive with the crosslinking agent by polymerization of a monomer that does not correspond to any of the above-mentioned monomers described as constituting the acrylic polymer (a11) and has a group reactive with the crosslinking agent, or may be crosslinked at a group reactive with the functional group derived from the energy ray-curable compound (a12).

The polymer (a1) contained in the composition (x1-2-1) and the first energy ray-curable resin film (x1-2) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000
[0113] In the compound (a2) having an energy ray-curable group and having a molecular weight of 100 to 80,000, the energy ray-curable group includes a group containing an energy ray-curable double bond, and preferred examples thereof include a (meth)acryloyl group and a vinyl group.

The compound (a2) is not particularly limited as long as it satisfies the above conditions, but examples thereof include low molecular weight compounds having energy ray curable groups, epoxy resins having energy ray curable groups, and phenolic resins having energy ray curable groups.

Among the compounds (a2), examples of the low molecular weight compound having an energy ray-curable group include polyfunctional monomers or oligomers, and acrylate compounds having a (meth)acryloyl group are preferred.
Examples of the acrylate-based compound include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane, tricyclodecane dimethanol di(meth)acrylate, 1,10-decane diol di(meth)acrylate, 1,2-dimethylphenyl di(meth)acrylate, 1,3-dimethylphenyl di(meth)acrylate, 1,4-dimethylphenyl di(meth)acrylate, 1,5-dimethylphenyl di(meth)acrylate, 1,6-dimethylphenyl di(meth)acrylate, 1,7-dimethylphenyl di(meth)acrylate, 1,8-dimethylphenyl di(meth)acrylate, 1,9-dimethylphenyl di(meth)acrylate, 1,10-dimethylphenyl ... bifunctional (meth)acrylates such as 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and 2-hydroxy-1,3-di(meth)acryloxypropane;
Polyfunctional (meth)acrylates such as tris(2-(meth)acryloxyethyl)isocyanurate, ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and dipentaerythritol hexa(meth)acrylate;
Examples of the polyfunctional (meth)acrylate oligomer include urethane (meth)acrylate oligomer.

Among the compounds (a2), examples of the epoxy resin having an energy ray-curable group and the phenolic resin having an energy ray-curable group that can be used include those described in paragraph 0043 of JP 2013-194102 A. Although such resins also fall under the category of resins constituting the thermosetting component described below, in the present invention they are treated as the compounds (a2).

The weight average molecular weight of compound (a2) is preferably 100 to 30,000, and more preferably 300 to 10,000.

The compound (a2) contained in the composition (x1-2-1) and the first energy ray-curable resin film (x1-2) may be only one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

(Polymer (b) Having No Energy Ray-Curable Group)
When the composition (x1-2-1) and the first energy ray curable resin film (x1-2) contain the compound (a2) as the energy ray curable component (a), they preferably further contain a polymer (b) having no energy ray curable group.
The polymer (b) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

Examples of the polymer (b) having no energy ray-curable group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber-based resins, and acrylic urethane resins.
Among these, the polymer (b) is preferably an acrylic polymer (hereinafter sometimes abbreviated as "acrylic polymer (b-1)").

The acrylic polymer (b-1) may be a known one, for example, a homopolymer of one type of acrylic monomer, a copolymer of two or more types of acrylic monomers, or a copolymer of one or more types of acrylic monomers and one or more types of monomers other than the acrylic monomers (non-acrylic monomers).

Examples of the acrylic monomer constituting the acrylic polymer (b-1) include (meth)acrylic acid alkyl esters, (meth)acrylic acid esters having a cyclic skeleton, glycidyl group-containing (meth)acrylic acid esters, hydroxyl group-containing (meth)acrylic acid esters, and substituted amino group-containing (meth)acrylic acid esters. Here, the "substituted amino group" is as explained above.

Examples of the (meth)acrylic acid alkyl ester include the same as the acrylic monomer not having the functional group (e.g., (meth)acrylic acid alkyl ester in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms) constituting the acrylic polymer (a11) described above.

Examples of the (meth)acrylic acid ester having a cyclic skeleton include cycloalkyl (meth)acrylic acid esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate;
(Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate;
(Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester;
(Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester are included.

Examples of the glycidyl group-containing (meth)acrylic acid ester include glycidyl (meth)acrylate.
Examples of the hydroxyl group-containing (meth)acrylic acid ester include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.
Examples of the substituted amino group-containing (meth)acrylic acid ester include N-methylaminoethyl (meth)acrylate.

Examples of the non-acrylic monomers that constitute the acrylic polymer (b-1) include olefins such as ethylene and norbornene; vinyl acetate; styrene; and the like.

The polymer (b) having no energy ray-curable group and at least a portion of which is crosslinked with a crosslinking agent may be, for example, a polymer in which a reactive functional group in the polymer (b) has reacted with a crosslinking agent.
The reactive functional group may be appropriately selected according to the type of crosslinking agent, and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, the reactive functional group may be a hydroxyl group, a carboxyl group, an amino group, etc., and among these, a hydroxyl group having high reactivity with an isocyanate group is preferred. When the crosslinking agent is an epoxy compound, the reactive functional group may be a carboxyl group, an amino group, an amide group, etc., and among these, a carboxyl group having high reactivity with an epoxy group is preferred. However, from the viewpoint of preventing corrosion of the circuits of a semiconductor wafer or a semiconductor chip, the reactive functional group is preferably a group other than a carboxyl group.

The polymer (b) having the reactive functional group and not having an energy ray curable group can be, for example, one obtained by polymerizing at least a monomer having the reactive functional group. In the case of the acrylic polymer (b-1), one or both of the acrylic monomers and non-acrylic monomers listed as the monomers constituting the polymer can be one having the reactive functional group. The polymer (b) having a hydroxyl group as a reactive functional group can be, for example, one obtained by polymerizing a hydroxyl group-containing (meth)acrylic acid ester, and also can be one obtained by polymerizing a monomer in which one or more hydrogen atoms in the acrylic monomers or non-acrylic monomers listed above are substituted with the reactive functional group.

In the polymer (b) having a reactive functional group, the ratio (content) of the amount of the structural units derived from the monomer having a reactive functional group to the total amount of the structural units constituting the polymer (b) is preferably 1 to 20% by mass, and more preferably 2 to 10% by mass. When the ratio is in this range, the degree of crosslinking in the polymer (b) becomes a more preferable range.

The weight average molecular weight (Mw) of the polymer (b) not having an energy ray-curable group is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000, in order to improve the film-forming properties of the composition (IV).

The polymer (b) not having an energy ray-curable group contained in the composition (x1-2-1) and the first energy ray-curable resin film (x1-2) may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

The composition (x1-2-1) may contain either one or both of the polymer (a1) and the compound (a2). When the composition (x1-2-1) contains the compound (a2), it is preferable that the composition (x1-2-1) further contains a polymer (b) that does not have an energy ray-curable group, and in this case, it is also preferable that the composition (x1-2-1) further contains the (a1). The composition (x1-2-1) may not contain the compound (a2), but may contain both the polymer (a1) and the polymer (b) that does not have an energy ray-curable group.

When composition (x1-2-1) contains the polymer (a1), the compound (a2), and the polymer (b) that does not have an energy ray-curable group, the content of the compound (a2) in composition (x1-2-1) is preferably 10 to 400 parts by mass, and more preferably 30 to 350 parts by mass, per 100 parts by mass of the total content of the polymer (a1) and the polymer (b) that does not have an energy ray-curable group.

In composition (x1-2-1), the ratio of the total content of the energy ray curable component (a) and the polymer (b) not having an energy ray curable group to the total content of components other than the solvent (i.e., in the first energy ray curable resin film (x1-2), the ratio of the total content of the energy ray curable component (a) and the polymer (b) not having an energy ray curable group to the total mass of the film) is preferably 5 to 90 mass%, more preferably 10 to 80 mass%, and particularly preferably 20 to 70 mass%. When the ratio is in such a range, the energy ray curability of the first energy ray curable resin film (x1-2) becomes better.

(filling material)
By adjusting the amount of the filler in the composition (x1-2-1) and the first energy ray curable resin film (x1-2), the X value can be adjusted more easily. In addition, by adjusting the amount of the filler in the composition (x1-2-1) and the first energy ray curable resin film (x1-2), the thermal expansion coefficient of the cured product of the first energy ray curable resin film (x1-2) can be adjusted more easily. For example, by optimizing the thermal expansion coefficient of the cured product of the first energy ray curable resin film (x1-2) for the object on which the protective film is formed, the reliability of the package obtained using the first energy ray curable resin film (x1-2) is further improved. In addition, by using the first energy ray curable resin film (x1-2) containing a filler, the moisture absorption rate of the cured product of the first energy ray curable resin film (x1-2) can be reduced or the heat dissipation property can be improved.

The filler contained in the composition (x1-2-1) and the first energy ray curable resin film (x1-2) is the same as the filler (D) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-1) described above.

The form of inclusion of the filler in the composition (x1-2-1) and the first energy ray curable resin film (x1-2) may be similar to the form of inclusion of the filler (D) in the composition (x1-1-1) and the first thermosetting resin film (x1-1).

The filler contained in the composition (x1-2-1) and the first energy ray curable resin film (x1-2) may be only one type or may be two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

In the composition (x1-2-1), the ratio of the content of the filler to the total content of all components other than the solvent (i.e., the ratio of the content of the filler in the first energy ray curable resin film (x1-2) to the total mass of the first energy ray curable resin film (x1-2)) may be, for example, 5 to 45% by mass. When the ratio is in such a range, when the first energy curable resin film (x1-2) is attached to the bump-forming surface of a wafer for producing semiconductor chips, the effect of suppressing the remaining of the first energy curable resin film (x1-2) on the upper part of the bump, the effect of suppressing the protrusion of the first energy curable resin film (x1-2), the effect of suppressing the repelling of the first energy curable resin film (x1-2) and its cured product on the bump-forming surface, and the effect of improving the embeddability of the first energy curable resin film (x1-2) in the groove are further enhanced, and the above-mentioned thermal expansion coefficient can be more easily adjusted.

(Additives)
The value of X can be more easily adjusted by adjusting the type or amount of the additive in the composition (x1-2-1) and the first energy ray-curable resin film (x1-2).

The additives contained in the composition (x1-2-1) and the first energy ray curable resin film (x1-2) are the same as the additives (I) contained in the composition (x1-1-1) and the first thermosetting resin film (x1-2) described above.
For example, preferred additives from the viewpoint of making it easier to adjust the X value include rheology control agents, surfactants, silicone oils, and the like.

The mode of inclusion of the additive in the composition (x1-2-1) and the first energy ray curable resin film (x1-2) may be similar to the mode of inclusion of the additive (I) in the composition (X1-1-1) and the first thermosetting resin film (x1-1).

The additives contained in the composition (x1-2-1) and the first energy ray curable resin film (x1-2) may be of only one type or of two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

The content of the additives in the composition (x1-2-1) and the first energy ray-curable resin film (x1-2) is not particularly limited and can be appropriately adjusted depending on the type and purpose.
For example, when the purpose is to adjust the X value, the ratio of the content of the additive to the total content of all components other than the solvent in the composition (x1-2-1) (i.e., the ratio of the content of the additive in the first energy ray curable resin film (x1-2) to the total mass of the first energy ray curable resin film (x1-2)) may be, for example, 0.5 to 10 mass%.

(Other ingredients)
The composition (x1-2-1) and the first energy ray curable resin film (x1-2) may contain other components that do not fall under any of the energy ray curable component (a), the filler, and the additives, within a range that does not impair the effects of the present invention.
Examples of the other components include a thermosetting component, a photopolymerization initiator, a coupling agent, a crosslinking agent, etc. For example, by using a composition (x1-2-1) containing the energy ray-curable component (a) and a thermosetting component, the adhesive strength of the first energy ray-curable resin film (x1-2) to an adherend is improved by heating, and the strength of the cured product of the first energy ray-curable resin film (x1-2) is also improved.

The thermosetting component, photopolymerization initiator, coupling agent, and crosslinking agent in composition (x1-2-1) may be the same as the thermosetting component (B), photopolymerization initiator, coupling agent (E), and crosslinking agent (F) in composition (x1-1-1), respectively.

The other components contained in the composition (x1-2-1) and the first energy ray-curable resin film (x1-2) may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.
The contents of the other components in the composition (x1-2-1) and the first energy ray-curable resin film (x1-2) are not particularly limited and may be appropriately selected depending on the purpose.

(solvent)
The composition (x1-2-1) preferably further contains a solvent. The composition (x1-2-1) containing a solvent has good handleability.
Examples of the solvent contained in the composition (x1-2-1) include the same solvents as those contained in the composition (x1-1-1) described above.
The solvent contained in the composition (x1-2-1) may be only one type, or may be two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.
The content of the solvent in the composition (x1-2-1) is not particularly limited and may be appropriately selected depending on, for example, the types of components other than the solvent.

<Method of producing the first energy ray-curable protective film-forming composition>
The first energy ray-curable resin film-forming composition (x1-2-1) can be obtained by blending the respective components constituting the composition.
The first energy ray curable resin film forming composition (x1-2-1) can be produced in the same manner as the first thermosetting resin film forming composition (x1-1-1) described above, except that the types of the blended components are different.

[First composite sheet (α1)]
As described above, the first curable resin film (x1) can be laminated with the first support sheet (Y1) to form the first composite sheet (α1).
An example of the structure of the first composite sheet (α1) is shown in FIG.
The first composite sheet (α1) is provided with a layer (X1) of a first curable resin (x1) on one side of a first support sheet (Y1) like the first composite sheet (α1) shown in Fig. 3. By providing the layer (X1) of the first curable resin (x1) on one side of the first support sheet (Y1), the layer (X1) of the first curable resin (x1) is stably supported and protected when the layer (X1) of the first curable resin (x1) is transported as a product package or when the layer (X1) of the first curable resin (x1) is conveyed in a process.

Specific examples of the configuration of the first composite sheet (α1) are shown in FIGS.
The first composite sheet (α1) is similar to the first composite sheet (α1a) shown in FIG. 4, in that the first support sheet (Y1) is a substrate 51, and a layer (X1) of a first curable resin (x1) is provided on one side of the substrate 51.
In addition, the first composite sheet (α1) may be, like the first composite sheet (α1b) shown in Figure 5, a first support sheet (Y1) which is an adhesive sheet formed by laminating a base material 51 and an adhesive layer 61, and the adhesive layer 61 of the adhesive sheet may be bonded to a layer (X1) of a first curable resin (x1).
Further, the first composite sheet (α1) may be an adhesive sheet in which the first support sheet (Y1) is a substrate 51, an intermediate layer 71, and an adhesive layer 61 are laminated in this order, as in the first composite sheet (α1c) shown in FIG. 6, and the adhesive layer 61 of the adhesive sheet and the layer (X1) of the first curable resin (x1) may be bonded together. An adhesive sheet in which the substrate 51, the intermediate layer 71, and the adhesive layer 61 are laminated in this order can be suitably used as a backgrind tape. That is, the first composite sheet (α1c) shown in FIG. 6 has a backgrind tape as the first support sheet (Y1), and therefore can be suitably used when grinding the back surface of the semiconductor chip fabrication wafer to thin it after bonding the layer (X1) of the first curable resin (x1) of the first composite sheet (α1c) to the bump formation surface of the semiconductor chip fabrication wafer.

The first curable resin (x1) and the first support sheet (Y1) used in the first composite sheet (α1) will be described below.
<First support sheet (Y1)>
The first support sheet (Y1) functions as a support for supporting the first curable resin (x1).
The first support sheet (Y1) may be composed of only a substrate 51 as shown in Fig. 4, or may be a laminate of a substrate 51 and an adhesive layer 61 as shown in Fig. 5, or may be a laminate in which a substrate 51, an intermediate layer 71, and an adhesive layer 61 are laminated in this order as shown in Fig. 6. A laminate in which a substrate 51, an intermediate layer 71, and an adhesive layer 61 are laminated in this order is suitable for use as a backgrind sheet (b-BG).

Below, we will explain the base material that the first support sheet (Y1) has, and the adhesive layer and intermediate layer that the first support sheet (Y1) may have.

(Base material)
The substrate is in the form of a sheet or film, and examples of the constituent materials thereof include the following various resins.
Examples of resins constituting the substrate include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer; vinyl chloride-based resins (copolymers obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymers. Examples of the polyesters include polyesters obtained by subjecting the polyester to an aromatic ring structure to an aromatic ring structure and the like, such as poly(ethylene terephthalate), poly(ethylene naphthalate), poly(butylene terephthalate), polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all of the constituent units have aromatic cyclic groups; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; and polyether ketones.
In addition, examples of the resin constituting the substrate include polymer alloys such as mixtures of the polyester and other resins. The polymer alloys of the polyester and other resins preferably contain a relatively small amount of resin other than polyester.
Examples of the resin constituting the substrate include crosslinked resins in which one or more of the resins exemplified above are crosslinked; and modified resins such as ionomers using one or more of the resins exemplified above.

The resin constituting the substrate may be used alone or in combination of two or more types. When the substrate is made up of two or more types of resin, the combination and ratio of the resins may be selected arbitrarily.

The substrate may be a single layer (single layer) or a multi-layer structure of two or more layers. When the substrate is a multi-layer structure, the multi-layer structure may be the same or different from each other, and the combination of the multi-layer structure is not particularly limited.

The thickness of the substrate is preferably 5 μm to 1,000 μm, more preferably 10 μm to 500 μm, even more preferably 15 μm to 300 μm, and even more preferably 20 μm to 150 μm.
Here, the "thickness of the substrate" means the thickness of the entire substrate. For example, the thickness of a substrate consisting of multiple layers means the total thickness of all layers constituting the substrate.

It is preferable that the substrate has a high thickness precision, i.e., that the thickness variation is suppressed regardless of the part. Among the above-mentioned constituent materials, examples of materials with a high thickness precision that can be used to constitute the substrate include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, and ethylene-vinyl acetate copolymer.

In addition to the main constituent materials such as the resin, the substrate may contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

The substrate may be transparent or opaque, may be colored according to the purpose, or may have other layers vapor-deposited thereon. In addition, when the first curable resin film (x1) is a first energy ray-curable resin film (x1-2), and when the pressure-sensitive adhesive layer is an energy-curable pressure-sensitive adhesive layer, it is preferable that the substrate transmits energy rays.

The substrate can be manufactured by a known method. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the resin.

(Adhesive Layer)
The pressure-sensitive adhesive layer is in the form of a sheet or film and contains a pressure-sensitive adhesive.
Examples of the adhesive include adhesive resins such as acrylic resins (adhesives made of resins having (meth)acryloyl groups), urethane resins (adhesives made of resins having urethane bonds), rubber resins (adhesives made of resins having a rubber structure), silicone resins (adhesives made of resins having siloxane bonds), epoxy resins (adhesives made of resins having epoxy groups), polyvinyl ethers, polycarbonates, etc. Among these, acrylic resins are preferred.

In the present invention, the term "adhesive resin" is a concept that includes both resins that have adhesive properties and resins that have adhesive properties, and includes, for example, not only resins that are adhesive in themselves, but also resins that exhibit adhesive properties when used in combination with other components such as additives, and resins that exhibit adhesive properties in the presence of a trigger such as heat or water.

The adhesive layer may be a single layer (single layer) or may be a multi-layer structure of two or more layers. When the adhesive layer is a multi-layer structure, these multi-layer structures may be the same or different from each other, and the combination of these multi-layer structures is not particularly limited.

The thickness of the adhesive layer is preferably 1 μm to 1000 μm, more preferably 5 μm to 500 μm, and even more preferably 10 μm to 100 μm. Here, the "thickness of the adhesive layer" means the thickness of the entire adhesive layer, and for example, the thickness of an adhesive layer consisting of multiple layers means the total thickness of all layers that make up the adhesive layer.

The adhesive layer may be formed using an energy ray curable adhesive or a non-energy ray curable adhesive. The adhesive layer formed using an energy ray curable adhesive can easily adjust the physical properties before and after curing.

(Middle class)
The intermediate layer is in the form of a sheet or film, and its constituent material may be appropriately selected according to the purpose, and is not particularly limited. For example, when the purpose is to suppress the deformation of the first cured resin film (r1) by reflecting the shape of the bumps present on the semiconductor surface in the protective film covering the semiconductor surface, a preferred constituent material of the intermediate layer is urethane (meth)acrylate, etc., in view of its high irregularity conformability and improved adhesion of the intermediate layer.

The intermediate layer may be a single layer (single layer) or may be two or more layers. When the intermediate layer is a multiple layer, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

The thickness of the intermediate layer can be adjusted as appropriate depending on the height of the bumps on the semiconductor surface to be protected, but since the effect of relatively tall bumps can be easily absorbed, it is preferably 50 μm to 600 μm, more preferably 70 μm to 500 μm, and even more preferably 80 μm to 400 μm. Here, the "thickness of the intermediate layer" means the thickness of the entire intermediate layer; for example, the thickness of an intermediate layer consisting of multiple layers means the total thickness of all the layers that make up the intermediate layer.

Next, we will explain the manufacturing method of the first composite sheet (α1).

[Method for producing first composite sheet (α1)]
The first composite sheet (α1) can be produced by laminating the above-mentioned layers in order so that they are in a corresponding positional relationship.
For example, when manufacturing the first support sheet (Y1), if a pressure-sensitive adhesive layer or an intermediate layer is laminated on a substrate, a pressure-sensitive adhesive composition or a composition for forming an intermediate layer can be applied to the substrate, and if necessary, dried or irradiated with energy rays, thereby laminating the pressure-sensitive adhesive layer or intermediate layer.
Examples of the coating method include spin coating, spray coating, bar coating, knife coating, roll coating, roll knife coating, blade coating, die coating, and gravure coating.

On the other hand, for example, when a first curable resin (x1) is further laminated on a pressure-sensitive adhesive layer already laminated on a substrate, it is possible to directly form a layer (X1) of the first curable resin (x1) by applying a thermosetting resin composition (x1-1-1) or an energy ray-curable resin composition (x1-2-1) on the pressure-sensitive adhesive layer.
Similarly, when a pressure-sensitive adhesive layer is laminated on an intermediate layer already laminated on a substrate, the pressure-sensitive adhesive composition can be applied onto the intermediate layer to directly form the pressure-sensitive adhesive layer.

In this way, when forming a continuous two-layer laminate structure using any of the compositions, it is possible to form a new layer by applying an additional composition on the layer formed from the composition. However, it is preferable that the layer to be laminated later out of these two layers is formed in advance using the composition on another release film, and the exposed surface of this formed layer opposite the side in contact with the release film is bonded to the exposed surface of the remaining layer that has already been formed to form a continuous two-layer laminate structure. In this case, it is preferable that the composition is applied to the release-treated surface of the release film. The release film can be removed as necessary after the laminate structure is formed.

[Second composite sheet (α2)]
The second composite sheet (α2) is not particularly limited as long as it has a configuration capable of forming a protective film on the rear surface of a semiconductor wafer, and for example, the same configuration as the first composite sheet (α1) can be adopted.
Therefore, the second hardening resin film (x2) of the second composite sheet (α2) may be made of the same material and have the same structure as the above-mentioned first hardening resin film (x1).
However, since the back surface of a semiconductor wafer is generally smooth and does not have bumps or grooves, the second curable resin film (x2) is not required to satisfy the requirement (I) for the first curable resin film (x1). Therefore, in the second curable resin film (x2), the X value may be 18 or less, or 10,000 or more.

(Colorant (J))
Here, from the viewpoint of improving the visibility of the marking formed by laser marking, and from the viewpoint of making grinding marks on the back surface of the semiconductor chip less visible to improve the design of the semiconductor chip, it is preferable that the second curable resin film (x2) and the composition for forming the second curable resin film (x2) contain a colorant (J).
Examples of the colorant (J) include known ones such as inorganic pigments, organic pigments, and organic dyes.
Examples of the organic pigments and organic dyes include aminium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squalium-based dyes, azulenium-based dyes, polymethine-based dyes, naphthoquinone-based dyes, pyrylium-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, naphtholactam-based dyes, azo-based dyes, condensed azo-based dyes, indigo-based dyes, perinone-based dyes, perylene-based dyes, dioxazine-based dyes, quinacridone-based dyes, isoindolinone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex dyes), dithiol metal complex-based dyes, indolephenol-based dyes, triarylmethane-based dyes, anthraquinone-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and threne-based colors.
Examples of the inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (indium tin oxide)-based pigments, and ATO (antimony tin oxide)-based pigments.

The colorant (J) contained in the second curable resin film (x2) and the composition for forming the second curable resin film may be one type or two or more types. When the colorant (J) is two or more types, the combination and ratio thereof can be selected arbitrarily.
When using the colorant (J), the content of the colorant (J) in the second curable resin film (x2) may be appropriately adjusted according to the purpose. For example, as described above, the second cured resin film (r2), which is a cured product formed by curing the second curable resin film (x2), may be printed by laser irradiation, and the visibility of the print can be adjusted by adjusting the content of the colorant (J) in the second curable resin (x2) and adjusting the light transmittance of the protective film. In addition, by adjusting the content of the colorant (J), the design of the protective film can be improved and the grinding marks on the back surface of the semiconductor wafer can be made less visible. Considering these points, in the second curable resin film forming composition for forming the second curable resin film (x2), the ratio of the content of the colorant (J) to the total content of all components other than the solvent (also referred to as the total mass of the solid content of the second curable resin film forming composition) (i.e., the content of the colorant (J) in the second curable resin film (x2)) is preferably 0.1 to 10 mass%, more preferably 0.1 to 7.5 mass%, and particularly preferably 0.1 to 5 mass%. When the content of the colorant (J) is equal to or greater than the lower limit, the effect of using the colorant (J) is more pronounced. In addition, when the content of the colorant (J) is equal to or less than the upper limit, excessive decrease in the light transmittance of the second curable resin film (x2) is suppressed.

In addition, the above-mentioned first curable resin film (x1) and the composition for forming the first curable resin film may also contain a colorant (J). However, from the viewpoint of ensuring the visibility of the planned dividing lines of the semiconductor chip manufacturing wafer, it is preferable that the content of the colorant (J) is within a range that ensures a level of transparency that ensures the visibility of the planned dividing lines.

The second support sheet (Y2) of the second composite sheet (α2) may have the same configuration as the first support sheet (Y1) described above. Specifically, the second support sheet (Y2) may be composed of only a substrate 51 as shown in Fig. 4, like the first support sheet (Y1), or may be an adhesive sheet in which a substrate 51 and an adhesive layer 61 are laminated as shown in Fig. 5, or may be an adhesive sheet in which a substrate 51, an intermediate layer 71, and an adhesive layer 61 are laminated as shown in Fig. 6.
The substrate, intermediate layer, and adhesive layer of the second support sheet (Y2) may have the same configuration and material as the substrate, intermediate layer, and adhesive layer of the first support sheet (Y1).

[Method of using the first curable resin film (x1)]
The first curable resin film (x1) is used to form a cured resin film (first cured resin film (r1)) as a protective film on both the bump-forming surface and the side surfaces of a semiconductor chip having a bump-forming surface with bumps.
More specifically, the first curable resin film (x1) is used to form a cured resin film (first cured resin film (r1)) as a protective film on both the bump-forming surface and side surfaces of a semiconductor chip having a bump-forming surface with bumps by a semiconductor chip manufacturing method described later using a semiconductor chip manufacturing wafer having a bump-forming surface with bumps and grooves as planned division lines.

[Method of using the second curable resin film (x2)]
The second curable resin film (x2) is used to form a cured resin film (second cured resin film (r2)) as a protective film on the back surface of a semiconductor chip having a bump-forming surface with bumps.
More specifically, the first curable resin film (x1) is used to form a cured resin film (second cured resin film (r2)) as a protective film on the back surface of a semiconductor chip having a bump-forming surface with bumps in step (T) of a semiconductor chip manufacturing method described later, which uses a semiconductor chip manufacturing wafer having a bump-forming surface with bumps and grooves as planned division lines.

[Method of using the first composite sheet (α1)]
The first composite sheet (α1) is used to form a cured resin film (first cured resin film (r1)) as a protective film on both the bump-forming surface and the side surfaces of a semiconductor chip having a bump-forming surface with bumps.
More specifically, the first composite sheet (α1) is used to form a cured resin film (first cured resin film (r1)) as a protective film on both the bump-forming surface and side surfaces of a semiconductor chip having a bump-forming surface with bumps by a semiconductor chip manufacturing method described later using a semiconductor chip manufacturing wafer having a bump-forming surface with bumps and grooves as planned division lines.

[Method of using the second composite sheet (α2)]
The second composite sheet (α2) is used to form a cured resin film (second cured resin film (r2)) as a protective film on the back surface of a semiconductor chip having a bump-forming surface with bumps.
More specifically, the second composite sheet (α2) is used to form a cured resin film (second cured resin film (r2)) as a protective film on the back surface of a semiconductor chip having a bump-forming surface with bumps in step (T) of the semiconductor chip manufacturing method described below, which uses a semiconductor chip manufacturing wafer having a bump-forming surface with bumps and grooves as planned division lines.

[Method of manufacturing a semiconductor chip according to the present invention]
FIG. 7 shows a schematic diagram of the steps of the method for producing a semiconductor chip according to the present invention.
The method for manufacturing a semiconductor chip of the present invention roughly includes a step (S1) of preparing a wafer for manufacturing semiconductor chips, a step (S2) of attaching a first composite sheet (α1), a step (S3) of curing a first curable resin (x1), and a step (S4) of singulating, and further includes a step (S-BG) of grinding the back surface of the wafer for manufacturing semiconductor chips.
In the method for producing a semiconductor chip according to one embodiment of the present invention, the first curable resin film (x1) may be used. However, from the viewpoint of improving handleability, it is preferable to use the first composite sheet (α1).

In detail, a method for manufacturing a semiconductor chip according to one embodiment of the present invention uses the above-mentioned first composite sheet (α1) and includes the following steps (S1) to (S4) in this order.
Step (S1): A step of preparing a semiconductor chip fabrication wafer having a bump-forming surface provided with bumps, the bump-forming surface of which is provided with bumps, and a groove portion as a division line is formed on the bump-forming surface without reaching the rear surface. Step (S2): A step of pressing and attaching a first curable resin (x1) to the bump-forming surface of the semiconductor chip fabrication wafer, covering the bump-forming surface of the semiconductor chip fabrication wafer with the first curable resin (x1), and embedding the first curable resin (x1) in the groove portion formed in the semiconductor chip fabrication wafer. Step (S3): A step of curing the first curable resin (x1) to obtain a semiconductor chip fabrication wafer with a first cured resin film (r1). Step (S4): A step of dividing the semiconductor chip fabrication wafer with the first cured resin film (r1) along the division lines to obtain semiconductor chips in which at least the bump-forming surface and side surfaces are covered with the first cured resin film (r1). Furthermore, the method includes the following step (S-BG) after the step (S2) and before the step (S3), after the step (S3) and before the step (S4), or in the step (S4).
Step (S-BG): Grinding the back surface of the semiconductor chip fabrication wafer

By using a manufacturing method including the above steps, a semiconductor chip can be obtained in which not only the bump-forming surface but also the side surfaces are covered with the first cured resin film (r1), and the chip has excellent strength and is less susceptible to peeling of the first cured resin film (r1) acting as a protective film.
In this case, "covered" means that the first cured resin film (r1) is formed on at least the bump-forming surface and the side surface of one semiconductor chip, following the shape of the semiconductor chip. In other words, the present invention is clearly different from the sealing technology that confines multiple semiconductor chips in resin.

Each step of the method for producing a semiconductor chip of the present invention will be described in detail below.
In the following description, a "semiconductor chip" will be referred to simply as a "chip", and a "semiconductor wafer" will be referred to simply as a "wafer".

[Step (S1)]
FIG. 8 shows a top view of an example of the semiconductor wafer prepared in step (S1), and FIG. 9 shows a schematic cross-sectional view thereof.
In step (S1), a semiconductor chip manufacturing wafer 10 is prepared, in which a groove portion 13 is formed as a planned division line on the bump forming surface 11a of the semiconductor wafer 11 having bumps 12 thereon so as not to reach the back surface 11b.
In addition, the bumps are not shown in FIG.

The shape of the bumps 12 is not particularly limited, and may be any shape as long as they can be brought into contact with and fixed to electrodes on a chip mounting substrate.
9, the bump 12 may be a spheroid. The spheroid may be, for example, a spheroid stretched in a direction perpendicular to the bump-forming surface 11a of the wafer 11, or a spheroid stretched in a direction horizontal to the bump-forming surface 11a of the wafer 11. The bump 12 may also be in a pillar shape.

The height of the bumps 12 is not particularly limited and may be changed as appropriate according to design requirements.
For example, it is 30 μm to 300 μm, preferably 60 μm to 250 μm, and more preferably 80 μm to 200 μm.
It should be noted that "the height of the bump 12" refers to the height of a single bump at its highest point from the bump-forming surface 11a.

The number of bumps 12 is not particularly limited and may be changed as appropriate according to design requirements.

Wafer 11 is a semiconductor wafer having circuits such as wiring, capacitors, diodes, and transistors formed on its surface. The material of the wafer is not particularly limited, and examples of the wafer include a silicon wafer, a silicon carbide wafer, a compound semiconductor wafer, a glass wafer, and a sapphire wafer.

The size of the wafer 11 is not particularly limited, but from the viewpoint of increasing batch processing efficiency, it is usually 8 inches (diameter 200 mm) or more, and preferably 12 inches (diameter 300 mm) or more. The shape of the wafer is not limited to a circle, and may be a polygonal shape such as a square or a rectangle. In the case of a polygonal wafer, it is preferable that the length of the longest side of the wafer 11 is equal to or greater than the above size (diameter) from the viewpoint of increasing batch processing efficiency.

The thickness of the wafer 11 is not particularly limited, but from the viewpoint of easily suppressing warping due to shrinkage when the first curable resin (x1) is cured, and from the viewpoint of reducing the amount of grinding of the back surface 11b of the wafer 11 in a subsequent process to shorten the time required for back surface grinding, the thickness is preferably 100 μm to 1,000 μm, more preferably 200 μm to 900 μm, and even more preferably 300 μm to 800 μm.

A plurality of grooves 13 are formed in a lattice pattern on the bump formation surface 11a of the semiconductor chip fabrication wafer 10 prepared in step (S1) as planned division lines when the semiconductor chip fabrication wafer 10 is diced. The plurality of grooves 13 are cut grooves formed when applying a blade tip dicing method (dicing before grinding), and are formed to a depth shallower than the thickness of the wafer 11 so that the deepest part of the grooves 13 does not reach the back surface 11b of the wafer 11. The plurality of grooves 13 can be formed by dicing using a conventionally known wafer dicing device equipped with a dicing blade. The plurality of grooves 13 can also be formed by dicing using a laser or the like instead of a blade.
The grooves 13 may be formed in any shape as long as the semiconductor chip to be manufactured has a desired size and shape, and the grooves 13 do not necessarily have to be formed in a lattice pattern as shown in Fig. 8. The size of a semiconductor chip is usually about 0.5 mm x 0.5 mm to 1.0 mm x 1.0 mm, but is not limited to this size.

From the viewpoint of improving the embeddability of the first curable resin (x1), the width of the groove portion 13 is preferably 10 μm to 2,000 μm, more preferably 30 μm to 1,000 μm, even more preferably 40 μm to 500 μm, and even more preferably 50 μm to 300 μm.

The depth of the groove 13 is adjusted according to the thickness of the wafer used and the required chip thickness, and is preferably 30 μm to 700 μm, more preferably 60 μm to 600 μm, and even more preferably 100 μm to 500 μm.

The aspect ratio of the groove 13 may be 2 to 6, or 2.5 to 5, or 3 to 5.

The semiconductor chip manufacturing wafer 10 prepared in step (S1) is subjected to step (S2).

[Step (S2)]
An outline of step (S2) is shown in FIG.
In the step (S2), a first hardening resin (x1) is pressed and attached to the bump formation surface 11a of the semiconductor chip fabrication wafer 10.
Here, from the viewpoint of the handleability of the first curable resin (x1), the first curable resin (x1) is preferably used by being laminated on a support sheet.
Therefore, in the step (S2), it is preferable to press and attach a first composite sheet (α1) having a laminated structure in which a first support sheet (Y1) and a layer (X1) of a first curable resin (x1) are laminated to the bump formation surface 11a of the semiconductor chip production wafer 10, using the layer (X1) as an attachment surface.
In step (S2), as shown in FIG. 4, the bump formation surface 11a of the semiconductor chip fabrication wafer 10 is covered with a first curable resin (x1), and the first curable resin (x1) is embedded in the groove portions 13 formed in the semiconductor chip fabrication wafer 10.

By embedding the first curable resin (x1) in the grooves 13 formed in the semiconductor chip fabrication wafer 10, the portions that will become the sides of the semiconductor chips when the semiconductor chip fabrication wafer 10 is diced in step (S4) can be covered with the first curable resin (x1). In other words, a coating that is a precursor of the first cured resin film (r1) that covers the sides of the semiconductor chips and is necessary to enhance the strength of the semiconductor chips and to suppress peeling of the first cured resin film (r1) as a protective film can be formed in step (S2).

In addition, the pressing force when attaching the first composite sheet (α1) to the semiconductor chip production wafer 10 is preferably 1 kPa to 200 kPa, more preferably 5 kPa to 150 kPa, and even more preferably 10 kPa to 100 kPa, from the viewpoint of improving the embedding property of the first curable resin (x1) into the groove portion 13.
The pressing force when attaching the first composite sheet (α1) to the semiconductor chip fabrication wafer 10 may be appropriately changed from the beginning to the end of attachment. For example, from the viewpoint of improving the embedding property of the first curable resin (x1) in the groove portion 13, it is preferable to make the pressing force low in the beginning of attachment and gradually increase the pressing force.

In addition, when the first composite sheet (α1) is attached to the semiconductor chip fabrication wafer 10, if the first curable resin (x1) is a thermosetting resin, it is preferable to heat the first curable resin (x1) from the viewpoint of improving the embedding property of the first curable resin (x1) in the groove portion 13. If the first curable resin (x1) is a thermosetting resin, the fluidity of the first curable resin (x1) is temporarily increased by heating, and the first curable resin (x1) is hardened by continuing to heat the first curable resin (x1). Therefore, by heating the first curable resin (x1) within a range in which the fluidity of the first curable resin (x1) is improved, the first curable resin (x1) can easily spread throughout the entire groove portion 13, and the embedding property of the first curable resin (x1) in the groove portion 13 can be further improved.
Specifically, the heating temperature (application temperature) is preferably 50°C to 150°C, more preferably 60°C to 130°C, and even more preferably 70°C to 110°C.
The heat treatment performed on the first hardening resin (x1) is not included in the hardening treatment of the first hardening resin (x1).

Furthermore, when attaching the first composite sheet (α1) to the semiconductor chip fabrication wafer 10, it is preferable to do so in a reduced pressure environment. This creates a negative pressure in the grooves 13, making it easier for the first curable resin (x1) to spread throughout the entire grooves 13. As a result, the first curable resin (x1) is more easily embedded in the grooves 13. The specific pressure of the reduced pressure environment is preferably 0.001 kPa to 50 kPa, more preferably 0.01 kPa to 5 kPa, and even more preferably 0.05 kPa to 1 kPa.

In addition, the thickness of the layer (X1) of the first hardening resin (x1) in the first composite sheet (α1) is preferably more than 30 μm and not more than 200 μm, more preferably 60 μm to 150 μm, and even more preferably 80 μm to 130 μm, from the viewpoint of further improving the embeddability of the first hardening resin (x1) into the groove portion 13.

Furthermore, the layer (X1) of the first hardening resin (x1) is composed of the first hardening resin (x1), and therefore satisfies the above requirement (I). Therefore, since the X value is 19 or more and less than 10,000, when the first composite sheet (α1) is attached to the bump-forming surface 11a of the semiconductor chip fabrication wafer 10, it has an excellent effect of suppressing the remaining of the first hardening resin (x1) on the upper part of the bump 12, the effect of suppressing the protrusion of the layer (X1) of the first hardening resin (x1), and the effect of suppressing the repelling of the first hardening resin (x1) and its hardened product, the first hardening resin film (r1), on the bump-forming surface 11a, and the embeddability of the first hardening resin (x1) in the groove portion 13 is also good.

Here, the first support sheet (Y1) of the first composite sheet (α1) preferably supports the first curable resin (x1) and also functions as a backgrind sheet.
In this case, when grinding the back surface 11b of the wafer 11 with the first composite sheet (α1) attached, the first support sheet (Y1) functions as a back-grinding sheet, making it easier to carry out the back-grinding process.

[Step (S3), Step (S4), and Step (S-BG)]
Through the steps up to the step (S2) above, a laminate is formed in which the first composite sheet (α1) is attached to and laminated on the semiconductor chip fabrication wafer 10. The laminate is preferably subjected to any of the steps according to the first to fourth embodiments described below, depending on the timing of carrying out the step (S-BG).
Hereinafter, for the first to fourth embodiments, step (S3) and step (S4) will be described together with an explanation of the timing for performing step (S-BG).

First Embodiment
In the first embodiment, as shown in FIG. 7, a step (S-BG) is performed after the step (S2) and before the step (S3).
FIG. 11 shows a schematic diagram relating to the first embodiment.

(First embodiment: step (S-BG))
In the first embodiment, first, the step (S-BG) is performed. Specifically, as shown in FIG. 11 (1-a), the back surface 11b of the semiconductor chip fabrication wafer 10 is ground with the first composite sheet (α1) attached. "BG" in FIG. 11 means back grinding, and the same applies to the subsequent figures. Next, as shown in FIG. 11 (1-b), the first support sheet (Y1) is peeled off from the first composite sheet (α1).
The amount of grinding when grinding the back surface 11b of the wafer 10 for manufacturing semiconductor chips should be an amount that exposes at least the bottom of the groove portion 13 of the wafer 10 for manufacturing semiconductor chips, but further grinding may be carried out so that the first curable resin (x1) embedded in the groove portion 13 is also ground together with the wafer 10 for manufacturing semiconductor chips.
In the first embodiment, since the first support sheet (Y1) is peeled off before carrying out the step (S3), even if the first curable resin (x1) is a thermosetting resin and a heat treatment for curing is carried out in the step (S3), the first support sheet (Y1) is not required to have heat resistance, and therefore the degree of freedom in designing the first support sheet (Y1) is improved.

(First embodiment: step (S3))
After the step (S-BG), the step (S3) is carried out. Specifically, as shown in FIG. 11 (1-c), the first curable resin (x1) is cured to obtain a semiconductor chip fabrication wafer 10 with a first cured resin film (r1).
The first cured resin film (r1) formed by curing the first cured resin (x1) is stronger than the first cured resin (x1) at room temperature. Therefore, by forming the first cured resin film (r1), the bump neck is well protected. In addition, in the step (S4) shown in (1-d) of FIG. 11, the semiconductor chip fabrication wafer 10 with the first cured resin film (r1) is divided into individual pieces, so that a semiconductor chip whose side surface is also covered with the first cured resin film (r1) can be obtained, and a semiconductor chip with excellent strength can be obtained. Moreover, peeling of the first cured resin film (r1) as a protective film is also suppressed.

(First embodiment: curing method)
The first curable resin (x1) can be cured by either heat curing or curing by irradiation with energy rays, depending on the type of the curable component contained in the first curable resin (x1).
As conditions for thermal curing, the curing temperature is preferably 100 to 200° C., more preferably 110 to 170° C., and particularly preferably 120 to 150° C. The heating time during the thermal curing is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 3 hours.
The conditions for curing by energy ray irradiation are appropriately set depending on the type of energy ray used. For example, when ultraviolet light is used, the illuminance is preferably 180 to 280 mW/ ^cm2 , and the light quantity is preferably 450 to 1000 mJ/ ^cm2 .
Here, in the process of curing the first curable resin (x1) to form the first cured resin film (r1), from the viewpoint of removing air bubbles and the like that may enter when filling the groove portion 13 with the first curable resin (x1) in the step (S2), the first curable resin (x1) is preferably a thermosetting resin. That is, when the first curable resin (x1) is a thermosetting resin, the fluidity of the first curable resin (x1) is temporarily increased by heating, and the first curable resin (x1) is cured by continuing the heating. By utilizing this phenomenon, when the fluidity of the first curable resin (x1) is increased, air bubbles and the like that may enter when filling the groove portion 13 with the first curable resin (x1) are removed, and the embeddability of the first curable resin (x1) in the groove portion 13 is improved, and then the first curable resin (x1) can be cured.
From the viewpoint of shortening the curing time, the first curable resin (x1) is preferably an energy ray curable resin.
The first curable resin (x1) for forming the first cured resin film (r1) will be described in detail later.

(First embodiment: step (S4))
After the step (S3), the step (S4) is carried out. Specifically, as shown in FIG. 11 (1-d), the portion of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 having the first cured resin film (r1) formed in the groove portion is cut along the planned division line.
The cutting can be appropriately carried out by adopting a conventionally known method such as blade dicing or laser dicing.
This makes it possible to obtain a semiconductor chip 40 in which at least the bump-forming surface 11a and the side surfaces are covered with the first cured resin film (r1).
The semiconductor chip 40 has excellent strength because the bump-forming surface 11a and the side are covered with the first cured resin film (r1). In addition, because the bump-forming surface 11a and the side are continuously covered with the first cured resin film (r1), the joint surface (interface) between the bump-forming surface 11a and the first cured resin film (r1) is not exposed on the side of the semiconductor chip 40. Among the joint surfaces (interfaces) between the bump-forming surface 11a and the first cured resin film (r1), the exposed portion exposed on the side of the semiconductor chip 40 is likely to become the starting point of film peeling. Since the semiconductor chip 40 of the present invention does not have the exposed portion, film peeling from the exposed portion is unlikely to occur during the process of cutting the semiconductor chip manufacturing wafer 10 to manufacture the semiconductor chip 40 or after manufacture. Therefore, a semiconductor chip 40 in which peeling of the first cured resin film (r1) as a protective film is suppressed can be obtained.

In step (S4), when the portion of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 with the first cured resin film (r1) that is formed in the groove portion is cut along the planned division line, it is preferable that the first cured resin film (r1) is transparent. Since the first cured resin film (r1) is transparent, the semiconductor wafer 11 can be seen through, ensuring visibility of the planned division line. This makes it easier to cut along the planned division line.

Second Embodiment
In the second embodiment, as shown in FIG. 4, a step (S-BG) is performed after the step (S3) and before the step (S4).
FIG. 6 shows a schematic diagram of the second embodiment.

(Second embodiment: step (S3))
In the second embodiment, first, step (S3) is carried out. Specifically, as shown in FIG. 12 (2-a), the first curable resin (x1) is cured with the first composite sheet (α1) attached to obtain a semiconductor chip fabrication wafer 10 with a first cured resin film (r1).
The first cured resin film (r1) formed by curing the first cured resin (x1) is stronger than the first cured resin (x1) at room temperature. Therefore, by forming the first cured resin film (r1), the bump neck is well protected. In addition, in step (S4), the semiconductor chip fabrication wafer 10 with the first cured resin film (r1) is divided into individual pieces, so that a semiconductor chip whose side surface is also covered with the first cured resin film (r1) can be obtained, and a semiconductor chip with excellent strength can be obtained. Moreover, peeling of the first cured resin film (r1) as a protective film is also suppressed.
The curing method may be the same as the curing method described in the first embodiment.
By performing the heat curing process without peeling off the first support sheet (Y1), it is possible to suppress the flow on the surface of the first curable resin (x1) that occurs temporarily when the first support sheet (Y1) cures the first curable resin (x1) during heat curing, and it is possible to improve the flatness of the first cured resin film (r1) on the bump formation surface. In addition, by curing the first curable resin (x1) before grinding the back surface 11b of the semiconductor chip fabrication wafer 10, warping of the semiconductor chip fabrication wafer 10 is suppressed.

(Second embodiment: step (S-BG))
After the step (S3), the step (S-BG) is carried out. As shown in FIG. 12(2-b), the back surface 11b of the semiconductor chip fabrication wafer 10 is ground with the first composite sheet (α1) attached.
The amount of grinding when grinding the back surface 11b of the wafer 10 for manufacturing semiconductor chips need only be an amount that exposes at least the bottom of the groove portion 13 of the wafer 10 for manufacturing semiconductor chips, but further grinding may be carried out so that the first cured resin film (r1) embedded in the groove portion 13 is also ground together with the wafer 10 for manufacturing semiconductor chips.
Next, as shown in FIG. 12(2-c), the first support sheet (Y1) is peeled off from the first composite sheet (α1).

(Second embodiment: step (S4))
After the step (S-BG) is performed, the step (S4) is performed in the same manner as in the first embodiment. Specifically, as shown in FIG. 12 (2-d), the portion of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 having the first cured resin film (r1) formed in the groove portion is cut along the planned division line.
The cutting can be appropriately carried out by adopting a conventionally known method such as blade dicing or laser dicing.
This makes it possible to obtain a semiconductor chip 40 in which at least the bump-forming surface 11a and the side surfaces are covered with the first cured resin film (r1).
The semiconductor chip 40 has excellent strength because the bump-forming surface 11a and the side surfaces are covered with the first cured resin film (r1). Also, for the reasons described above, the semiconductor chip 40 can be obtained in which peeling of the first cured resin film (r1) serving as a protective film is suppressed.

Third Embodiment
The third embodiment is common to the second embodiment in that a step (S-BG) is performed after the step (S3) and before the step (S4), as shown in Fig. 4. However, the third embodiment differs from the second embodiment in that a back grind sheet (b-BG) is separately used.
FIG. 13 shows a schematic diagram of the third embodiment.

(Third embodiment: step (S3))
In the third embodiment, first, step (S3) is performed, but before that, the first support sheet (Y1) is peeled off from the first composite sheet (α1) as shown in FIG. 13(3-a). Then, step (S3) is performed. Specifically, as shown in FIG. 13(3-b), the first curable resin (x1) is cured to obtain a semiconductor chip fabrication wafer 10 with a first cured resin film (r1).
The curing method may be the same as the curing method described in the first embodiment.
Since the first support sheet (Y1) is peeled off before carrying out the step (S3), even if the first curable resin (x1) is a thermosetting resin and a heat treatment is carried out for curing in the step (S3), the first support sheet (Y1) is not required to have heat resistance, and therefore the degree of freedom in designing the first support sheet (Y1) is improved.
Furthermore, by hardening the first hardening resin (x1) before grinding the back surface 11b of the semiconductor chip fabrication wafer 10, warping of the semiconductor chip fabrication wafer 10 is suppressed.

(Third embodiment: step (S-BG))
After carrying out step (S3), step (S-BG) is carried out. Specifically, as shown in (3-c) of FIG. 13, a back grind sheet (b-BG) is attached to the surface of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 with the first cured resin film (r1). Next, as shown in (3-d) of FIG. 13, the back surface 11b of the semiconductor chip fabrication wafer 10 is ground with the back grind sheet (b-BG) attached, and then, as shown in (3-e) of FIG. 13, the back grind sheet (b-BG) is peeled off from the semiconductor chip fabrication wafer 10 with the first cured resin film (r1).
Since the backgrind sheet (b-BG) is not used in step (S3), even if the first curable resin (x1) is a thermosetting resin and a heat treatment is performed for curing in step (S3), the backgrind sheet (b-BG) is not required to have heat resistance. Therefore, the degree of freedom in designing the backgrind sheet (b-BG) is improved.
The amount of grinding when grinding the back surface 11b of the wafer 10 for manufacturing semiconductor chips need only be an amount that exposes at least the bottom of the groove portion 13 of the wafer 10 for manufacturing semiconductor chips, but further grinding may be carried out so that the first cured resin film (r1) embedded in the groove portion 13 is also ground together with the wafer 10 for manufacturing semiconductor chips.

(Third embodiment: step (S4))
After carrying out the step (S-BG), the step (S4) is carried out in the same manner as in the first and second embodiments. Specifically, as shown in (3-f) of Fig. 13, the portion of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 having the first cured resin film (r1) formed in the groove portion is cut along the planned division line.
The cutting can be appropriately carried out by adopting a conventionally known method such as blade dicing or laser dicing.
This makes it possible to obtain a semiconductor chip 40 in which at least the bump-forming surface 11a and the side surfaces are covered with the first cured resin film (r1).
The semiconductor chip 40 has excellent strength because the bump-forming surface 11a and the side surfaces are covered with the first cured resin film (r1). Also, for the reasons described above, the semiconductor chip 40 can be obtained in which peeling of the first cured resin film (r1) serving as a protective film is suppressed.

<Fourth embodiment>
In the fourth embodiment, as shown in FIG. 4, the step (S-BG) is carried out in the step (S4).
FIG. 14 shows a schematic diagram of the fourth embodiment.

(Fourth embodiment: step (S3))
In the fourth embodiment, first, step (S3) is performed, but before that, as shown in (4-a) of Fig. 14, the first support sheet (Y1) is peeled off from the first composite sheet (α1). Then, step (S3) is performed. Specifically, as shown in (4-b) of Fig. 14, the first curable resin (x1) is cured to obtain a semiconductor chip fabrication wafer 10 with a first cured resin film (r1).
The curing method may be the same as the curing method described in the first embodiment.
Since the first support sheet (Y1) is peeled off before carrying out the step (S3), even if the first curable resin (x1) is a thermosetting resin and a heat treatment is carried out for curing in the step (S3), the first support sheet (Y1) is not required to have heat resistance, and therefore the degree of freedom in designing the first support sheet (Y1) is improved.
Furthermore, by hardening the first hardening resin (x1) before grinding the back surface 11b of the semiconductor chip fabrication wafer 10, warping of the semiconductor chip fabrication wafer 10 is suppressed.

(Fourth embodiment: step (S4) including step (S-BG))
After carrying out step (S3), as shown in (4-c) of FIG. 14, a cut is made along the intended division line in the portion of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 having the first cured resin film (r1) formed in the groove portion 13. From the viewpoint of facilitating singulation, the depth of the cut is preferably set to a depth that reaches the deepest portion of the groove portion 13. As a result, in step (S-BG) described later, the semiconductor chip fabrication wafer 10 having the first cured resin film (r1) is singulated along the cut.
Alternatively, although not shown, a modified region may be formed along the planned division line in the portion of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 with the first cured resin film (r1) that is formed in the groove portion 13. The modified region can be formed by laser or plasma treatment, etc. As a result, in a step (S-BG) described later, cracks are generated starting from the modified region, and the semiconductor chip fabrication wafer 10 with the first cured resin film (r1) is divided into individual pieces along the modified region.
Next, the process (S-BG) is carried out. Specifically, as shown in FIG. 14 (4-d), a backgrind sheet (b-BG) is attached to the surface of the first cured resin film (r1) of the semiconductor chip fabrication wafer 10 with the first cured resin film (r1). Next, as shown in FIG. 14 (4-e), the back surface 11b of the semiconductor chip fabrication wafer 10 is ground with the backgrind sheet (b-BG) attached. Finally, as shown in FIG. 14 (4-f), the backgrind sheet (b-BG) is peeled off from the semiconductor chip fabrication wafer 10 with the first cured resin film (r1).
This makes it possible to obtain a semiconductor chip 40 in which at least the bump-forming surface 11a and the side surfaces are covered with the first cured resin film (r1).
The amount of grinding when grinding the back surface 11b of the wafer 10 for manufacturing semiconductor chips need only be an amount that exposes at least the bottom of the groove portion 13 of the wafer 10 for manufacturing semiconductor chips, but further grinding may be carried out so that the first cured resin film (r1) embedded in the groove portion 13 is also ground together with the wafer 10 for manufacturing semiconductor chips.
The semiconductor chip 40 has excellent strength since the bump-forming surface 11a and the side surfaces are covered with the first cured resin film (r1).
In addition, since the backgrind sheet (b-BG) is not used in the step (S3), even if the first curable resin (x1) is a thermosetting resin and a heat treatment is performed for curing in the step (S3), the backgrind sheet (b-BG) is not required to have heat resistance. Therefore, the degree of freedom in designing the backgrind sheet (b-BG) is improved.

Here, in the first to fourth embodiments, an embodiment in which a first support sheet (Y1) or a back-grind sheet (b-BG) is used in step (S-BG) has been described. However, in one aspect of the present invention, a resin layer (Z1) for back-grinding may be formed instead of the first support sheet (Y1) or the back-grind sheet (b-BG).
Specifically, a flowable resin (z1) is used to cover the surface of the first cured resin film (r1) and also to cover the bumps exposed from the first cured resin film (r1), and then the resin (z1) is cured to form a resin layer (Z1) for backgrinding, which can be used as a substitute for a backgrind sheet to perform the grinding process.
When the surface of the first cured resin film (r1) and the bumps exposed from the first cured resin film (r1) are covered with the resin (z1), a flexible resin film (z2) capable of conforming to the unevenness of the bumps is interposed between them, which makes it easier to peel off the resin layer (Z1) for back grinding that is no longer needed after the step (S-BG).

[Process (T)]
In one aspect of the method for producing a semiconductor chip of the present invention, it is preferable that the method further includes the following step (T).
Step (T): forming a second cured resin film (r2) on the back surface of the semiconductor chip fabrication wafer.

According to the manufacturing method of the above embodiment, it is possible to obtain a semiconductor chip 40 in which at least the bump-forming surface 11a and the side surface are covered with the first cured resin film (r1). However, the back surface of the semiconductor chip 40 is exposed. Therefore, from the viewpoint of protecting the back surface of the semiconductor chip 40 and further improving the strength of the semiconductor chip 40, it is preferable to carry out the above-mentioned process (T).

More specifically, the above step (T) preferably includes the following steps (T1) to (T2) in this order.
Step (T1): A step of attaching a second curable resin (x2) to the back surface of a semiconductor chip fabrication wafer Step (T2): A step of curing the second curable resin (x2) to form a second curable resin film (r2) In addition, in step (T1), it is preferable to use a second laminate (α2) having a laminate structure in which a second support sheet (Y2) and a layer (X2) of the second curable resin (x2) are laminated. In detail, it is preferable that step (T1) is a step of attaching a second laminate (α2) having a laminate structure in which a second support sheet (Y2) and a layer (X2) of the second curable resin (x2) are laminated to the back surface of a semiconductor chip fabrication wafer, using the layer (X2) as an attachment surface.
In this case, the timing for peeling off the second support sheet (Y2) from the second laminate (α2) may be between the step (T1) and the step (T2), or after the step (T2).

Here, when the second laminate (α2) is used in the step (T1), it is preferable that the second support sheet (Y2) of the second composite sheet (α2) supports the second curable resin (x2) and also functions as a dicing sheet.
In the manufacturing methods of the first to third embodiments, since the second composite sheet (α2) is attached to the back surface 11b of the semiconductor wafer 10 with the first cured resin film (r1) in step (S4), the second support sheet (Y2) functions as a dicing sheet when dicing into individual pieces, making it easier to perform dicing.

Here, when step (S3) is carried out after step (S-BG) as in the manufacturing method according to the first embodiment, the above step (T1) may be carried out before carrying out step (S3), and then step (S3) and step (T2) may be carried out simultaneously. That is, the first curable resin (x1) and the second curable resin (x2) may be cured simultaneously in a lump. This makes it possible to reduce the number of times the curing process is performed.

Specifically, in the production methods according to the first to third embodiments, the step (T) includes the following step (T1-1) and the following step (T1-2) in this order:
- Step (T1-1): A step of attaching a second curable resin (x2) to the back surface of the semiconductor chip production wafer after step (S-BG) and before step (S4) - Step (T1-2): A step of curing the second curable resin (x2) to form a second cured resin film (r2) before or after step (S4). In step (S4), when the portion of the first cured resin film (r1) of the semiconductor chip production wafer with the first cured resin film (r1) that is formed in the groove portion is cut along the planned division line, it is preferable to also cut the second curable resin (x2) or the second cured resin film (r2) at the same time.
In the production method according to the fourth embodiment, the step (T) includes the following step (T2-1) and the following step (T2-2) in this order:
Step (T2-1): After step (S-BG) and after step (S4), a step of attaching a second curable resin (x2) to the back surface of the semiconductor chip production wafer with the backgrind sheet (b-BG) still attached. Step (T2-2): A step of curing the second curable resin (x2) to form a second cured resin film (r2). Furthermore, it is preferable that step (T) includes the following step (T2-3) before or after step (T2-2).
Step (T2-3): Step of dividing the second cured resin layer (x2) or the second cured resin film (r2) along the kerf

[Other steps]
In one embodiment of the method for manufacturing a semiconductor chip of the present invention, other steps may be included without departing from the spirit of the present invention.
Examples of such treatment include wet etching and dry etching of the bump formation surface after the formation of the protective film (first cured resin film (r1)).

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

1. Raw materials for producing the first thermosetting resin film-forming composition (x1-1-1) Raw materials used for producing the first thermosetting resin film-forming composition (x1-1-1) are shown below.

（式中、ｌ_１は約２８であり、ｍ_１は１～３であり、ｎ_１は６８～７４の整数である。） (1) Polymer component (A)
(A)-1: Polyvinyl butyral having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3 ("S-LEC BL-10" manufactured by Sekisui Chemical Co., Ltd., weight average molecular weight 25,000, glass transition temperature 59°C).
(A)-2: Acrylic resin (weight average molecular weight 800,000, glass transition temperature -28°C) obtained by copolymerizing butyl acrylate (55 parts by mass), methyl acrylate (10 parts by mass), glycidyl methacrylate (20 parts by mass), and 2-hydroxyethyl acrylate (15 parts by mass).

(wherein l ₁ is about 28, m ₁ is 1 to 3, and n ₁ is an integer from 68 to 74.)

(2) Epoxy resin (B1)
(B1)-1: Liquid modified bisphenol A type epoxy resin (manufactured by DIC Corporation, "Epicron EXA-4850-150", molecular weight 900, epoxy equivalent 450 g/eq)
(B1)-2: Liquid bisphenol F type epoxy resin ("YL983U" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 165 to 175 g/eq)
(B1)-3: Polyfunctional aromatic epoxy resin ("EPPN-502H" manufactured by Nippon Kayaku Co., Ltd.), epoxy equivalent: 158 to 178 g/eq)
(B1)-4: Dicyclopentadiene type epoxy resin (DIC Corporation, "Epicron HP-7200HH", epoxy equivalent 254 to 264 g/eq)

(3) Heat curing agent (B2)
(B2)-1: Novolac type phenolic resin ("BRG-556" manufactured by Showa Denko K.K.)
(B2)-2: O-cresol novolak resin (DIC Corporation, "Phenolite KA-1160")

(4) Curing accelerator (C)
(C)-1: 2-phenyl-4,5-dihydroxymethylimidazole ("Curesol 2PHZ-PW" manufactured by Shikoku Chemical Industry Co., Ltd.)

(5) Filler (D)
(D)-1: Spherical silica modified with epoxy groups ("Admanano YA050C-MKK" manufactured by Admatechs Co., Ltd., average particle size 50 nm)

(6) Additives (I)
(I)-1: Surfactant (acrylic polymer, "BYK-361N" manufactured by BYK Corporation)
(I)-2: Silicone oil (aralkyl-modified silicone oil, "XF42-334" manufactured by Momentive Performance Materials Japan, LLC)
(I)-3: Rheology control agent (polyhydroxycarboxylic acid ester, "BYK-R606" manufactured by BYK Corporation)

2. Examples 1 to 2, Comparative Examples 1 to 3
2-1. Example 1
(1) Production of the first thermosetting resin film-forming composition (x1-1-1) Polymer component (A)-1 (100 parts by mass), epoxy resin (B1)-1 (350 parts by mass), epoxy resin (B1)-4 (270 parts by mass), (B2)-1 (190 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (90 parts by mass), and additive (I)-3 (9 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23 ° C. to obtain a thermosetting resin film-forming composition (x1-1-1) having a total concentration of all components other than the solvent of 45% by mass. Note that the blending amounts of all components other than the solvent shown here are the blending amounts of the target product not including the solvent.

(2) Production of First Thermosetting Resin Film (x1-1) A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) in which one side of a polyethylene terephthalate film had been subjected to a silicone treatment for release treatment was used, and the composition (x1-1-1) obtained above was applied to the release-treated surface, followed by drying by heating at 120° C. for 2 minutes to form a first thermosetting resin film (x1-1) having a thickness of 45 μm.

2-2. Example 2 and Comparative Examples 1 to 3
A first thermosetting resin film (x1-1) having a thickness of 45 μm was formed in the same manner as in Example 1, except that either or both of the types and amounts of the components blended during the production of the first thermosetting resin film-forming composition (x1-1-1) were changed so that the types and contents of the components contained in the first thermosetting resin film-forming composition (x1-1-1) were as shown in Table 1 described below.
In addition, the notation "-" in the column of contained components in Table 1 means that the first thermosetting resin film-forming composition (x1-1-1) does not contain the component.

3. Evaluation 3-1. Production of first composite sheet (α1) A backgrind tape ("E-8510HR" manufactured by Lintec Corporation) was used as the first support sheet (Y1), and this backgrind tape was bonded to the first thermosetting resin film (x1-1) on the release film of each of Examples 1 to 2 and Comparative Examples 1 to 3 obtained above. This resulted in a first composite sheet (α1) in which the first support sheet (Y1) and the first thermosetting resin film (x1-1) were laminated.

3-2. Measurement of Gc1 and Gc300 of the first thermosetting resin film (x1-1), and calculation of the X value Twenty sheets of the first thermosetting resin film (x1-1) having a thickness of 50 μm were prepared in the same manner as above, except that the coating amount of the composition (x1-1-1) was changed. Next, these first thermosetting resin films (x1-1) were laminated, and the obtained laminated film was cut into a disk shape having a diameter of 25 mm, thereby preparing a test piece of the first thermosetting resin film (x1-1) having a thickness of 1 mm.
The location where the test piece was to be placed in a viscoelasticity measuring device ("MCR301" manufactured by Anton Paar) was kept warm at 90°C in advance, and the test piece of the first thermosetting resin film (x1-1) obtained above was placed on this location, and the test piece was fixed to the location by pressing a measuring tool against the upper surface of the test piece.
Next, the strain generated in the test piece was increased stepwise in the range of 0.01% to 1000% under the conditions of a temperature of 90°C and a measurement frequency of 1 Hz, and the storage modulus Gc of the test piece was measured. Then, the X value was calculated from the measured values of Gc1 and Gc300. The results are shown in Table 1.

3-3. Measurement of overhang amount of first thermosetting resin film (x1-1) A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) in which one side of a polyethylene terephthalate film had been subjected to a silicone treatment for release treatment was used, and the composition (x1-1-1) obtained above was applied to the release-treated surface, followed by drying by heating at 120° C. for 2 minutes to form a first thermosetting resin film (x1-1) having a thickness of 30 μm.
Next, this first thermosetting resin film (x1-1) was processed together with the release film into a circular shape having a diameter of 170 mm to prepare a test piece with a release film.
The entire exposed surface of the obtained test piece (in other words, the surface opposite to the side provided with the release film) was bonded to the surface of a transparent strip-shaped backgrind tape ("E-8180" manufactured by Lintec Corporation) to obtain the laminate shown in Figure 15. Figure 15 is a plan view showing the state of the obtained laminate as viewed from above the backgrind tape side.
As shown here, the obtained laminate 101 is composed of a backgrind tape 107, a test piece 120 (first thermosetting resin film (x1-1)), and a release film, which are laminated in this order in the thickness direction.

Next, the release film was removed from the obtained laminate, and the newly produced exposed surface of the test piece (in other words, the surface of the test piece opposite to the side provided with the backgrind tape) was pressed against one surface of a silicon wafer having a diameter of 12 inches, thereby attaching the test piece to the surface of the silicon wafer. At this time, the test piece was attached to the surface of the silicon wafer while heating the first thermosetting resin film (x1-1) using an attachment device (roller type laminator, "RAD-3510 F/12" manufactured by Lintec Corporation) under the conditions of table temperature: 90°C, attachment speed: 2 mm/sec, attachment pressure: 0.5 MPa, and roller attachment height: -200 μm.
Next, for the test piece with the backgrind tape attached to the silicon wafer, the maximum length of the line segment connecting two different points on the circumference was measured, and the measured value (the maximum length of the line segment) was used to calculate the protrusion amount (mm) of the test piece (in other words, the first thermosetting resin film (x1-1)) by the method described with reference to Figure 2. The results are shown in Table 1.
When the amount of protrusion was 170 mm, it was determined that there was no change in shape from the original test piece and no protrusion had occurred.On the other hand, when the amount of protrusion exceeded 170 mm, it was determined that there was a change in shape from the original test piece and protrusion had occurred.

3-4. Confirmation of the presence or absence of the first thermosetting resin film (x1-1) on the top of the bumps The release film was removed from the first composite sheet (α1) obtained in "3-1. Production of the first composite sheet (α1)", and the surface (exposed surface) of the first thermosetting resin film (x1-1) thus exposed was pressed against the bump-formed surface of a semiconductor wafer having a diameter of 8 inches and having bumps, thereby attaching the first composite sheet (α1) from which the release film had been removed to the bump-formed surface of the semiconductor wafer. In this case, the semiconductor wafer used had bumps with a height of 210 μm, a width of 250 μm, and a distance between the bumps of 400 μm. The first composite sheet (α1) was attached using a laminating device (roller type laminator, "RAD-3510 F/12" manufactured by Lintec Corporation) under the conditions of table temperature: 90°C, lamination speed: 2 mm/sec, lamination pressure: 0.5 MPa, and roller lamination height: -200 μm, while heating the first composite sheet (α1).
Next, the first support sheet (Y1) was removed from the first thermosetting resin film (x1-1) using a multi-wafer mounter ("RAD-2700 F/12" manufactured by Lintec Corporation) to expose the first thermosetting resin film (x1-1).
Next, using a scanning electron microscope (SEM, Keyence Corporation "VE-9700"), the surface of the bumps on the semiconductor wafer was observed from a direction that was at an angle of 60° to the direction perpendicular to the bump-forming surface of the semiconductor wafer, and the presence or absence of residues of the first thermosetting resin film (x1-1) on the top of the bumps was confirmed. If residues were present on the top of the bumps, it was judged as "residues present," and if no residues were present on the top of the bumps, it was judged as "no residues present." The results are shown in Table 1.

3-5. Confirmation of the Presence or Absence of Cracks of the First Thermosetting Resin Film (x1-1) on the Bump-Formed Surface The presence or absence of cracking due to the cured product of the first thermosetting resin film (x1-1) on the bump-formed surface of the semiconductor chip was examined using a 12-inch semiconductor wafer on which no bumps were formed.
Specifically, a 12-inch silicon wafer on which no bumps were formed was used, and the first composite sheet (α1) was attached in the same manner as in the above-mentioned "3-4. Confirmation of the presence or absence of remaining thermosetting resin film (x1-1) on top of the bumps," and the first support sheet (Y1) was removed from the first thermosetting resin film (x1-1).
Next, the first thermosetting resin film attached to the semiconductor wafer was heat-treated using a pressure oven ("RAD-9100" manufactured by Lintec Corporation) under heating conditions of temperature: 130°C, time: 2 hours, and furnace pressure: 0.5 MPa, thereby thermally curing the first thermosetting resin film (x1-1).
Next, the entire laminate of the cured product (first cured resin film (r1)) of the first thermosetting resin film (x1-1) and the semiconductor wafer was observed from the cured product side using an optical microscope (Keyence Corporation, "VHX-1000"). If there was an area where the exposed semiconductor wafer could be directly confirmed, it was judged as "there is cissing", and if there was no area where the exposed semiconductor wafer could be directly confirmed, it was judged as "there is no cissing".

3-5. Evaluation of embedding ability in grooves (1) Preparation of wafer for semiconductor chip production A 12-inch silicon wafer (wafer thickness 750 μm) in which the planned dividing line was half-cut was used as a wafer for semiconductor chip production. The width of the half-cut part of the silicon wafer (width of the groove) was 60 μm, and the depth of the groove was 230 μm.

(2) Evaluation Method The release film was removed from the first composite sheet (α1) obtained in “3-1. Production of first composite sheet (α1)”, and the surface (exposed surface) of the first thermosetting resin film (x1-1) exposed thereby was attached to the surface side (half-cut forming surface) of a semiconductor chip production wafer while pressing it under the following conditions.
・Lamination device: Fully automatic laminating machine (manufactured by Lintec Corporation, product name "RAD-3510")
Roller pressure: 0.5 MPa
・Roller height: -400 μm
Application speed: 5 mm/sec
Application temperature: 90°C
Next, the first support sheet (Y1) was peeled off from the first thermosetting resin film (x1-1), and the semiconductor chip fabrication wafer with the first thermosetting resin film (x1-1) attached thereto was heated at 130° C. for 4 hours to harden the wafer and form a first cured resin film (r1). The semiconductor chip fabrication wafer was then cut from the half-cut formation surface toward the back surface, and the embedding property of the first cured resin film (r1) in the grooves of the half-cut portions was observed with an optical microscope (Keyence Corporation, “VHX-1000”).
The evaluation criteria for embeddability were as follows.
S: No distortion was observed in the shape of the first cured resin film (r1), and the embedding property was the best.
A: Although some distortion is observed in the shape of the first cured resin film (r1) near the entrance of the groove, the embedding property is good.
B: The embedding property is poor.

4. Results The components contained in the first thermosetting resin film-forming composition (x1-1-1) and the evaluation results are shown in Table 1.
FIG. 16 shows the results of "3-5. Evaluation of embedding ability in grooves" (photographs in place of drawings).

The results shown in Table 1 reveal the following:
In Examples 1 and 2, in which the X value is 19 or more and less than 10,000, no protrusion was observed, no residue was left on the top of the bump, no repelling was observed when applied, and the groove filling properties were also good.
In contrast, when the X value is less than 19 as in Comparative Examples 1 and 3, it is found that one or more of the following occurs: protrusion, generation of residue on the upper part of the bump, and poor embeddability.
16, it can be seen that the groove filling property is poor when the protrusion occurs as in Comparative Example 1. In Comparative Example 3, the first thermosetting resin film (x1-1) did not enter the grooves.
Furthermore, when the X value is 10,000 or more as in Comparative Example 2, it is found that repelling occurs on the bump formation surface.

From the above results, it was found that by subjecting a semiconductor chip manufacturing wafer with a first cured resin film (r1) formed using the first thermosetting resin film (x1-1) of Examples 1 and 2 to the above-mentioned process (S4) and process (S-BG) and singulating it, it is possible to obtain semiconductor chips whose bump-forming surfaces and side surfaces are well coated with the first cured resin film (r1).

10 Semiconductor chip manufacturing wafer 11 Wafer 11a Bump forming surface 11b Back surface 12 Bump 13 Groove portion 40 Semiconductor chip x1 First curable resin r1 First curable resin film X1 Layer Y1 First support sheet α1 First composite sheet x2 Second curable resin r2 Second curable resin film X2 Layer Y2 Second support sheet α2 Second composite sheet 51 Substrate 61 Pressure-sensitive adhesive layer 71 Intermediate layer

Claims (14)

A curable resin film is used to form a cured resin film as a protective film on both a bump-forming surface and a side surface of a semiconductor chip having bumps on the bump-forming surface, and satisfies the following requirement (I):
<Requirement (I)>
A strain is generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage modulus of the test piece is measured. When the storage modulus of the test piece when the strain of the test piece is 1% is defined as Gc1 and the storage modulus of the test piece when the strain of the test piece is 300% is defined as Gc300, the X value calculated by the following formula (i) is 19 or more and 500 or less .
X=Gc1/Gc300...(i) The curable resin film according to claim 1, wherein, in requirement (I), Gc300 is less than 15,000. It is used to form a cured resin film as a protective film on both the bump-forming surface and the side surface of a semiconductor chip having bumps on the bump-forming surface,
The support sheet and the curable resin layer are laminated to form a laminate structure.
A composite sheet, wherein the curable resin is the curable resin film according to claim 1 or 2. A method of using the curable resin film according to claim 1 or 2 to form a cured resin film as a protective film on both the bump-forming surface and the side surface of a semiconductor chip having a bump-forming surface. A method of using the composite sheet according to claim 3 to form a cured resin film as a protective film on both the bump-forming surface and the side surface of a semiconductor chip having a bump-forming surface with bumps. A method for manufacturing a semiconductor chip, comprising the steps of:
The method includes the following steps (S1) to (S4) in this order:
Step (S1): A step of preparing a semiconductor chip fabrication wafer having a bump-forming surface provided with bumps, the bump-forming surface of the semiconductor wafer being provided with grooves as planned division lines formed on the bump-forming surface without reaching the rear surface. Step (S2): A step of pressing and attaching a first curable resin (x1) to the bump-forming surface of the semiconductor chip fabrication wafer, covering the bump-forming surface of the semiconductor chip fabrication wafer with the first curable resin (x1), and embedding the first curable resin (x1) in the grooves formed in the semiconductor chip fabrication wafer. Step (S3): A step of curing the first curable resin (x1) to obtain a semiconductor chip fabrication wafer with a first cured resin film (r1). Step (S4): A step of dividing the semiconductor chip fabrication wafer with the first cured resin film (r1) along the planned division lines to obtain semiconductor chips in which at least the bump-forming surface and side surfaces are covered with the first cured resin film (r1). The method further comprises the following step (S-BG) after the step (S2) and before the step (S3), after the step (S3) and before the step (S4), or in the step (S4),
Step (S-BG): Grinding the back surface of the semiconductor chip production wafer. A method for producing a semiconductor chip, comprising the step of: using the curable resin film according to claim 1 or 2 as the first curable resin (x1). The method for manufacturing a semiconductor chip according to claim 6, wherein the step (S2) is performed by pressing and attaching a first composite sheet (α1) having a laminated structure in which a first support sheet (Y1) and a layer (X1) of the first curable resin (x1) are laminated to the bump formation surface of the semiconductor chip manufacturing wafer, with the layer (X1) as an attachment surface. The step (S-BG) is included after the step (S2) and before the step (S3),
The step (S-BG) is carried out by grinding the back surface of the semiconductor chip production wafer with the first composite sheet (α1) attached, and then peeling the first support sheet (Y1) from the first composite sheet (α1),
8. The method for manufacturing a semiconductor chip according to claim 7, wherein the step (S4) is carried out by cutting the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer with the first cured resin film (r1) that is formed in the groove portion along the planned division line. The step (S-BG) is included after the step (S3) and before the step (S4),
The step (S3) is carried out without peeling the first support sheet (Y1) from the first composite sheet (α1);
The step (S-BG) is carried out by grinding the back surface of the semiconductor chip production wafer with the first composite sheet (α1) attached, and then peeling the first support sheet (Y1) from the first composite sheet (α1),
8. The method for manufacturing a semiconductor chip according to claim 7, wherein the step (S4) is carried out by cutting the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer with the first cured resin film (r1) that is formed in the groove portion along the planned division line. The step (S-BG) is included after the step (S3) and before the step (S4),
After the step (S2) and before the step (S3), the first support sheet (Y1) is peeled off from the first composite sheet (α1);
The step (S-BG) is carried out by attaching a backgrind sheet (b-BG) to the surface of the first cured resin film (r1) of the semiconductor chip production wafer having the first cured resin film (r1), grinding the back surface of the semiconductor chip production wafer with the backgrind sheet (b-BG) attached, and then peeling off the backgrind sheet (b-BG) from the semiconductor chip production wafer having the first cured resin film (r1);
8. The method for manufacturing a semiconductor chip according to claim 7, wherein the step (S4) is carried out by cutting the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer with the first cured resin film (r1) that is formed in the groove portion along the planned division line. The step (S-BG) is included in the step (S4),
After the step (S2) and before the step (S3), the first support sheet (Y1) is peeled off from the first composite sheet (α1);
The method for producing a semiconductor chip according to claim 7, wherein the step (S4) is performed by making an incision along the planned division line in a portion of the first cured resin film (r1) of the semiconductor chip production wafer with the first cured resin film (r1) formed in the groove portion, or by forming a modified region along the planned division line, and then, as the step (S-BG), attaching a backgrind sheet (b-BG) to the surface of the first cured resin film (r1) of the semiconductor chip production wafer with the first cured resin film (r1), and grinding the back surface of the semiconductor chip production wafer with the backgrind sheet (b-BG) attached. The method for producing a semiconductor chip according to any one of claims 6 to 11, further comprising the following step (T):
Step (T): forming a second cured resin film (r2) on the back surface of the semiconductor chip fabrication wafer. The method for manufacturing a semiconductor chip according to any one of claims 6 to 12, wherein the width of the groove is 10 μm to 2000 μm. The method for manufacturing a semiconductor chip according to any one of claims 6 to 13, wherein the depth of the groove is 30 μm to 700 μm.

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