JP7640250B2 - Dicing adhesive film with spacer - Google Patents

Description

The present invention relates to a spacer-equipped dicing adhesive film that is used, for example, when manufacturing semiconductor integrated circuits.

A method for manufacturing semiconductor integrated circuits generally includes a front-end process of forming a circuit surface on one side of a wafer using highly integrated electronic circuits, and a back-end process of cutting chips out of the wafer with the circuit surface formed thereon and assembling them.
With the recent progress in integration technology, in the post-process, for example, NAND memory chips may be stacked multiple times to assemble a semiconductor integrated circuit. In this case, for example, a semiconductor integrated circuit is manufactured having a structure in which multiple storage NAND chips are stacked on a control controller chip. In such a semiconductor integrated circuit, for example, a spacer layer is disposed between the control controller chip and the storage NAND chip closest to the control controller chip.

Processing films used in the manufacture of semiconductor integrated circuits as described above are known. There are various types of processing films according to the purpose, and they are used in the above-mentioned post-processing steps according to the purpose.
As a processing film, for example, a dicing die bond film for attaching a semiconductor chip to an adherend is known. The dicing die bond film includes a dicing tape having a base layer and a pressure-sensitive adhesive layer, and a die bond layer laminated on the pressure-sensitive adhesive layer of the dicing tape and adhered to the adherend.
On the other hand, as a processing film, a spacer-attached dicing adhesive film is known which has a spacer layer, an adhesive layer for adhering the spacer layer to the adherend, and a dicing tape superimposed on the adhesive layer in order to adhere the spacer layer to the adherend.

For example, in the post-processing of semiconductor integrated circuits, a dicing die-bond film having a dicing tape and a die-bonding layer is used as a processing film, and as shown in FIG. 1A, a first step is performed in which a controller chip w' for control, which has been diced using the dicing die-bonding film, is fixed to the surface of an adherend (such as a wiring board Z) via a die-bonding layer d'. Next, a spacer-attached dicing adhesive film having a dicing tape, an adhesive layer, and a spacer layer is used as a processing film, and the spacer layer, which has been diced using the film, is fixed to the surface of an adherend (such as a wiring board) via an adhesive layer as shown in FIG. 1B. Next, a third step is performed in which a dicing die-bonding film as described above is used as a processing film, and as shown in FIG. 1C, a memory NAND chip w" is fixed on the spacer layer 10 via a die-bonding layer d", and memory NAND chips w" are stacked in the same manner.
Through these steps, the above-mentioned semiconductor integrated circuit is manufactured.

Here, in the second step, for example, a spacer-attached dicing adhesive film with a spacer layer formed from a thin silicon wafer is used, and the following steps are carried out: forming grooves in the spacer layer and adhesive layer by blade dicing or the like and splitting the film into small pieces; peeling the small pieces of the spacer layer with the adhesive layer attached from the dicing tape; and adhering the spacer layer with the adhesive layer attached to the adherend (wiring board).

In this type of semiconductor integrated circuit manufacturing method, the spacer-equipped dicing adhesive film used in the second step is known to have a spacer layer made of metal foil instead of a spacer layer made of a silicon wafer (for example, see Patent Document 1).

Specifically, the spacer layer in the spacer-attached dicing adhesive film described in Patent Document 1 is a metal foil such as rolled steel foil or stainless steel foil.
According to the spacer-attached dicing adhesive film described in Patent Document 1, since the spacer layer is a metal foil instead of a silicon wafer, stable production and supply can be maintained without being affected by a shortage of silicon wafers. In addition, since the back grinding process for thinning the silicon wafer is not required, the manufacturing process of the semiconductor integrated circuit can be simplified.

By the way, in order to ensure electrical insulation between the NAND memory chips that are stacked on top of the spacer layer and the wiring board using the spacer layer, electrically insulating materials such as resins are more suitable for constructing the spacer layer than conductive metals.

JP 2007-220913 A

Therefore, it is conceivable to prepare a spacer layer using an electrically insulating resin or the like, and use a spacer-attached dicing adhesive film having a laminated sheet in which the spacer layer and the adhesive layer are bonded together in the second step described above.

However, when a simple laminated sheet of an electrically insulating spacer layer and an adhesive layer is cut into small pieces on a dicing tape in the second step described above and peeled off from the dicing tape, there are cases in which the cut-out laminated sheet cannot be picked up due to poor peeling, etc.
In order to prevent such problems, there is a demand for a spacer-equipped dicing adhesive film that has good pick-up properties when peeling the small pieces of the laminated sheet from the dicing tape.

However, it cannot be said that sufficient research has been done yet on a spacer-attached dicing adhesive film that has good pick-up properties when peeling off a laminated sheet of a spacer layer and an adhesive layer from a dicing tape.

The present invention aims to provide a spacer-attached dicing adhesive film that has good pick-up properties when peeling off a laminated sheet of a spacer layer and an adhesive layer from a dicing tape.

In order to solve the above problems, the dicing adhesive film with spacers according to the present invention has the following features:
A laminated sheet having an adhesive layer that is adhered to an adherend and a spacer layer that overlaps one surface of the adhesive layer;
a dicing tape that overlaps the other surface of the adhesive layer of the laminated sheet and holds the laminated sheet,
The laminate sheet has a bending stiffness of 0.05 N·mm ² or more at room temperature.
The spacer-attached dicing adhesive film having the above-mentioned configuration provides good pick-up properties when the laminated sheet of the spacer layer and adhesive layer is peeled off from the dicing tape.

In the above-mentioned spacer-attached dicing adhesive film, the elastic modulus of the laminated sheet is preferably 1 GPa or more. This improves the pick-up properties when peeling the laminated sheet of the spacer layer and adhesive layer from the dicing tape.

In the above-mentioned dicing adhesive film with spacers, the peel strength between the adhesive layer and the spacer layer may be 0.1 N/20 mm or more.
In the above-mentioned dicing adhesive film with spacers, the spacer layer may have a thickness of 3 μm or more and 300 μm or less.
In the above-mentioned spacer-attached dicing adhesive film, the adhesive layer may have a thickness of 10 μm or more and 200 μm or less.
This improves the pick-up properties when the laminated sheet of the spacer layer and the adhesive layer is peeled off from the dicing tape.

In the above-mentioned spacer-attached dicing adhesive film, the material of the spacer layer is preferably at least one selected from the group consisting of polyimide, polyamideimide, polyester, polybenzimidazole, polyetherimide, polyphenylene sulfide, and polyetheretherketone. This improves the pick-up properties when peeling off the laminated sheet of the spacer layer and adhesive layer from the dicing tape.

The above-mentioned spacer-equipped dicing adhesive film may be used to embed a semiconductor chip when manufacturing a chip-embedded type semiconductor integrated circuit, or to ensure space for stacking a memory semiconductor chip on a control semiconductor chip when manufacturing a wire-embedded type semiconductor integrated circuit.

The spacer-attached dicing adhesive film of the present invention exhibits good pick-up properties when peeling the laminated sheet of the spacer layer and adhesive layer from the dicing tape.

1A to 1C are schematic cross-sectional views illustrating an example of a manufacturing process for a semiconductor integrated circuit. 1A to 1C are schematic cross-sectional views illustrating an example of a manufacturing process for a semiconductor integrated circuit. 1A to 1C are schematic cross-sectional views illustrating an example of a manufacturing process for a semiconductor integrated circuit. FIG. 2 is a schematic perspective view of a dicing adhesive film with spacers according to the present embodiment. 2 is a cross-sectional view of the spacer-attached dicing adhesive film of the present embodiment cut in the thickness direction. FIG. 1 is a cross-sectional view showing a schematic diagram of a state in which a dicing adhesive film with a spacer is used (mounted) in a manufacturing method of a semiconductor integrated circuit. FIG. 2 is a cross-sectional view showing a schematic diagram of a state in which a dicing adhesive film with a spacer is used (blade dicing) in a method for manufacturing a semiconductor integrated circuit. FIG. 1 is a cross-sectional view showing a schematic view of a state in which a dicing adhesive film with spacers is used in a method for manufacturing a semiconductor integrated circuit (after blade dicing). 1 is a cross-sectional view showing a schematic diagram of a state in which a dicing adhesive film with a spacer is used (pickup) in a method for manufacturing a semiconductor integrated circuit. FIG. 11 is a cross-sectional view illustrating another example of a semiconductor integrated circuit. FIG. 11 is a cross-sectional view illustrating another example of a semiconductor integrated circuit. FIG. 11 is a cross-sectional view illustrating another example of a semiconductor integrated circuit. FIG. 11 is a cross-sectional view illustrating another example of a semiconductor integrated circuit. FIG. 11 is a cross-sectional view illustrating another example of a semiconductor integrated circuit. 5A to 5C are schematic cross-sectional views each showing a process for producing a laminate sheet having a spacer layer and an adhesive layer. 5A to 5C are schematic cross-sectional views each showing a process for producing a laminate sheet having a spacer layer and an adhesive layer. 3A to 3C are schematic cross-sectional views each showing a state during the production of the spacer-equipped dicing adhesive film of the present embodiment. 1 is a schematic cross-sectional view showing a cross section of a dicing adhesive film with spacers during production, cut along the longitudinal direction. FIG. 3A to 3C are schematic cross-sectional views each showing a state during the production of the spacer-equipped dicing adhesive film of the present embodiment. 1 is a schematic cross-sectional view showing a cross section of a dicing adhesive film with spacers during production, cut along the longitudinal direction. FIG. 1 is a schematic cross-sectional view showing a cross section of a dicing adhesive film with spacers during production, cut along the longitudinal direction. FIG. 1 is a schematic cross-sectional view showing a cross section of a dicing adhesive film with spacers during production, cut along the longitudinal direction. FIG. 3A to 3C are schematic cross-sectional views each showing a state during the production of the spacer-equipped dicing adhesive film of the present embodiment. 1 is a schematic cross-sectional view showing a cross section of a dicing adhesive film with spacers during production, cut along the longitudinal direction. FIG. 1 is a schematic cross-sectional view showing a cross section of a dicing adhesive film with spacers during production, cut along the longitudinal direction. FIG. 1 is a schematic cross-sectional view showing a cross section of a dicing adhesive film with spacers during production, cut along the longitudinal direction. FIG. FIG. 4 is a schematic cross-sectional view showing another example of the spacer-attached dicing adhesive film of the present embodiment. FIG. 13 is a schematic cross-sectional view showing another example of a dicing adhesive film with spacers in the process of being manufactured.

Below, an embodiment of the spacer-equipped dicing adhesive film according to the present invention will be described with reference to the drawings.

The spacer-attached dicing adhesive film 1 of this embodiment is a long sheet, as shown in Fig. 2, and is stored in a rolled state until it is used. A cross-sectional view cut in the thickness direction along line III-III in Fig. 2 is shown in Fig. 3.
As shown in FIG. 3, the spacer-attached dicing adhesive film 1 of this embodiment includes a laminated sheet having an adhesive layer 20 to be attached to an adherend and a spacer layer 10 overlapping one surface of the adhesive layer 20;
and a dicing tape 30 overlapping the other surface of the adhesive layer 20 of the laminated sheet and holding the laminated sheet. The adhesive layer 20 is to be adhered to an adherend such as a circuit board or a semiconductor chip in the manufacture of a semiconductor integrated circuit.
As shown in Figures 2 and 3, when the spacer-attached dicing adhesive film 1 is viewed from one side in the thickness direction, the dicing tape 30 is strip-shaped, and the spacer layer 10 and the adhesive layer 20 are circular and aligned along the longitudinal direction of the dicing tape 30.
The spacer-attached dicing adhesive film 1 of this embodiment can be used by adhering the adhesive layer 20 to the substrate Z so as to embed a controller chip w′ for control by the adhesive layer 20. The spacer-attached dicing adhesive film 1 of this embodiment can also be used to adhere a NAND memory chip w″ onto the spacer layer 10 adhered to the substrate Z via the adhesive layer 20.
As shown in Figure 3, the spacer-attached dicing adhesive film 1 of this embodiment may further include a protective film (peeling tape H) that protects the surface of the spacer layer 10 and a portion of the surface of the adhesive layer 32 of the dicing tape 30.

<Spacer Layer of Dicing Adhesive Film with Spacer>
The thickness (average thickness) of the spacer layer 10 may be 3 μm or more and 300 μm or less, or may be 3 μm or more and 100 μm or less.
The thickness of the spacer layer 10 is calculated by averaging the thickness measurements at at least five randomly selected points. When the spacer layer 10 is a laminate, the thickness of the spacer layer 10 is the thickness of the laminate (total thickness of the spacer layer 10).

The spacer layer 10 is usually made of a resin. The spacer layer 10 usually contains at least 50% by mass of a resin. The material of the spacer layer 10 is preferably at least one selected from the group consisting of polyimide, polyamideimide, polyester, polybenzimidazole, polyetherimide, polyphenylene sulfide, and polyetheretherketone, more preferably at least one of polyimide and polyetherimide, and even more preferably polyimide.
In other words, the spacer layer 10 is preferably made of polyimide, polyamideimide, polyester (eg, polyethylene terephthalate), polybenzimidazole, polyetherimide, polyphenylene sulfide, polyether ether ketone, or the like.
The above-mentioned material for the spacer layer 10 has an advantage that the spacer layer 10 can have sufficient electrical insulation properties, and also has an advantage that the spacer layer 10 can have heat resistance to high temperatures, for example, about 260° C., when a reflow soldering process is performed in the manufacture of semiconductor integrated circuits.

<Adhesive layer of dicing adhesive film with spacer>
The thickness (average thickness) of the adhesive layer 20 is not particularly limited, but is, for example, 1 μm or more and 200 μm or less. The thickness is preferably 10 μm or more and 200 μm or less, and more preferably 20 μm or more and 150 μm or less. When the adhesive layer 20 is a laminate, the thickness of the adhesive layer 20 is the thickness of the laminate (total thickness of the adhesive layer 20).
The thickness of adhesive layer 20 is calculated by averaging thickness measurements at at least 10 randomly selected locations.
When the adhesive layer 20 has a relatively large thickness, for example, 100 μm or more, it is preferably used for FOD applications (applications for embedding semiconductor chips when manufacturing chip-embedded semiconductor integrated circuits) described later.
When the thickness of the adhesive layer 20 is relatively thin, for example less than 100 μm, it is suitably used for FOW applications (applications for securing space for stacking a memory semiconductor chip on top of a control semiconductor chip when manufacturing a wire-embedded type semiconductor integrated circuit) described below.

The adhesive layer 20 may have a single-layer structure, for example, as shown in Fig. 3. In this specification, a single layer means having only layers formed of the same composition. A form in which multiple layers formed of the same composition are laminated is also a single layer.
On the other hand, the adhesive layer 20 may have a multi-layer structure in which layers each formed of two or more different compositions are laminated.

The adhesive layer 20 may contain at least one of a thermosetting resin and a thermoplastic resin. It is preferable that the adhesive layer 20 contains a thermosetting resin and a thermoplastic resin.

Examples of thermosetting resins include epoxy resins, phenolic resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. As the thermosetting resin, only one type or two or more types are used. As the thermosetting resin, epoxy resins are preferred because they contain less ionic impurities that can cause corrosion of the semiconductor chip to be die-bonded. As a curing agent for epoxy resins, phenolic resins are preferred.

Examples of the epoxy resins include bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, orthocresol novolac type, trishydroxyphenylmethane type, tetraphenylolethane type, hydantoin type, trisglycidyl isocyanurate type, and glycidylamine type epoxy resins.

Phenol resins can act as curing agents for epoxy resins. Examples of phenol resins include novolac-type phenol resins, resol-type phenol resins, and polyoxystyrenes such as polyparaoxystyrene.
Examples of novolac-type phenolic resins include phenol novolac resins, phenol aralkyl resins, cresol novolac resins, tert-butylphenol novolac resins, and nonylphenol novolac resins.
As the phenolic resin, one kind or two or more kinds may be adopted.

In the adhesive layer 20, the hydroxyl groups of the phenolic resin are preferably 0.5 equivalents or more and 2.0 equivalents or less, more preferably 0.7 equivalents or more and 1.5 equivalents or less, per equivalent of the epoxy groups of the epoxy resin. This allows the curing reaction between the epoxy resin and the phenolic resin to proceed sufficiently.

When the adhesive layer 20 contains a thermosetting resin, the content of the thermosetting resin in the adhesive layer 20 is preferably 5% by mass or more and 60% by mass or less, and more preferably 10% by mass or more and 50% by mass or less, relative to the total mass of the adhesive layer 20. This allows the adhesive layer 20 to properly function as a thermosetting adhesive.

Examples of thermoplastic resins that can be included in the adhesive layer 20 include natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resins such as 6-polyamide resin and 6,6-polyamide resin, phenoxy resin, acrylic resin, saturated polyester resins such as PET and PBT, polyamideimide resin, and fluororesin.
As the thermoplastic resin, an acrylic resin is preferable since it has a small amount of ionic impurities and a high heat resistance, and therefore the adhesiveness of the adhesive layer 20 can be further ensured.
As the thermoplastic resin, one kind or two or more kinds may be adopted.

The acrylic resin is preferably a polymer in which the constituent units in the molecule are primarily alkyl (meth)acrylates, such as C2 to C4 alkyl (meth)acrylates.
The acrylic resin may contain a structural unit derived from another monomer component copolymerizable with the alkyl (meth)acrylate monomer.
Examples of the other monomer components include carboxy group-containing monomers, acid anhydride monomers, hydroxy group (hydroxyl group)-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, functional group-containing monomers such as acrylamide and acrylonitrile, and various other polyfunctional monomers.
The acrylic resin is preferably a copolymer of an alkyl(meth)acrylate (particularly an alkyl(meth)acrylate having an alkyl portion with 4 or less carbon atoms), a carboxy group-containing monomer, a nitrogen atom-containing monomer, and a polyfunctional monomer (particularly a polyglycidyl-based polyfunctional monomer), in that it can exert a higher cohesive force in the adhesive layer 20, and more preferably a copolymer of ethyl acrylate, butyl acrylate, acrylic acid, acrylonitrile, and polyglycidyl(meth)acrylate.

When the adhesive layer 20 contains a thermosetting resin and a thermoplastic resin, the content of the thermoplastic resin in the adhesive layer 20 is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, and even more preferably 20% by mass or more and 40% by mass or less, based on the total mass of organic components excluding the filler (e.g., thermosetting resin, thermoplastic resin, curing catalyst, silane coupling agent, dye). By changing the content of the thermosetting resin, the elasticity and viscosity of the adhesive layer 20 can be adjusted.

When the thermoplastic resin of the adhesive layer 20 has a thermosetting functional group, for example, a thermosetting functional group-containing acrylic resin can be used as the thermoplastic resin. This thermosetting functional group-containing acrylic resin preferably contains a structural unit derived from an alkyl (meth)acrylate in the molecule in the largest mass ratio. Examples of the alkyl (meth)acrylate include the alkyl (meth)acrylates exemplified above.
On the other hand, examples of the thermosetting functional group in the thermosetting functional group-containing acrylic resin include a glycidyl group, a carboxy group, a hydroxyl group, and an isocyanate group.
The adhesive layer 20 preferably contains a thermosetting functional group-containing acrylic resin and a curing agent. Examples of the curing agent include those exemplified as curing agents that can be contained in the adhesive layer 32. When the thermosetting functional group in the thermosetting functional group-containing acrylic resin is a glycidyl group, it is preferable to use a compound having multiple phenol structures in the molecule as the curing agent. For example, the above-mentioned various phenol resins can be used as the curing agent.

The adhesive layer 20 preferably contains a filler. By changing the amount of the filler in the adhesive layer 20, the elasticity and viscosity of the adhesive layer 20 can be more easily adjusted. Furthermore, the physical properties of the adhesive layer 20, such as electrical conductivity, thermal conductivity, and elastic modulus, can be adjusted.
The filler may be an inorganic filler or an organic filler, and the inorganic filler is preferred.
Examples of inorganic fillers include fillers containing aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, boron nitride, silica such as crystalline silica and amorphous silica, etc. Examples of the material of the inorganic filler include simple metals such as aluminum, gold, silver, copper, nickel, etc., and alloys, etc. Fillers such as aluminum borate whiskers, amorphous carbon black, graphite, etc. The shape of the filler may be various shapes such as spherical, needle-like, and flake-like. As the filler, only one of the above types or two or more types are used.

When the adhesive layer 20 contains a filler, the content of the filler is preferably 30% by mass or more and 70% by mass or less, more preferably 40% by mass or more and 60% by mass or less, and even more preferably 40% by mass or more and 55% by mass or less, relative to the total mass of the adhesive layer 20.

The adhesive layer 20 may contain other components as necessary, such as a curing catalyst, a flame retardant, a silane coupling agent, an ion trapping agent, and a dye.
Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resins.
Examples of the silane coupling agent include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane.
Examples of the ion trapping agent include hydrotalcites, bismuth hydroxide, and benzotriazole.
As the other additives, one kind may be used alone, or two or more kinds may be used in combination.

The adhesive layer 20 preferably contains a thermoplastic resin (particularly, an acrylic resin), a thermosetting resin, and a filler, in that the elasticity and viscosity can be easily adjusted.
Relative to the total mass of the adhesive layer 20, the content ratio of the thermoplastic resin and the thermosetting resin is preferably 20 mass% or more and 95 mass% or less, more preferably 30 mass% or more and 90 mass% or less, and even more preferably 40 mass% or more and 85 mass% or less.

When using the spacer-attached dicing adhesive film 1 of this embodiment, the adhesive layer 20 may be hardened by a heat treatment or the like. For example, the adhesive layer 20 with the spacer layer 10 may be adhered to the substrate Z so as to cover the controller chip w' for control on the substrate Z with the adhesive layer 20, and then the adhesive layer 20 may be hardened by a heat treatment (e.g., curing at 70°C or higher and 150°C or lower).

<Laminated Sheet (Spacer Layer and Adhesive Layer) in Dicing Adhesive Film with Spacer>
The bending stiffness of the laminate sheet in which the spacer layer 10 and the adhesive layer 20 are laminated at room temperature is 0.05 N· ^mm2 or more. Such bending stiffness is more preferably 0.10 N· ^mm2 or more, even more preferably 0.50 N· ^mm2 or more, and particularly preferably 2.0 N· ^mm2 or more.
Since the bending stiffness is 0.05 N ^mm2 or more, when the laminate sheet is pushed up through the dicing tape 30, for example as shown in FIG. 4D, the laminate sheet is easily peeled off from the dicing tape 30. In detail, since the bending stiffness is a relatively high value of 0.05 N ^mm2 or more, when the laminate sheet is pushed up as described above, it is possible to suppress the deformation of the laminate sheet following the deformation of the dicing tape 30. Since the deformation of the laminate sheet is suppressed, the force when pushed up is easily converted into a force for peeling. Therefore, the pickup performance is good.
The above bending rigidity may be 25.0 N· ^mm2 or less, or may be 20.0 N· ^mm2 or less.
Room temperature is, for example, 20° C. or higher and 25° C. or lower, and 25° C. may be adopted as room temperature.

The bending stiffness is calculated by the following formula (1). In formula (1), b represents the longitudinal length (the length of one side in the case of a square) of the rectangular spacer layer 10 (the size when used after being cut into small pieces by dicing), F represents the tensile modulus of elasticity, h represents the thickness of the laminated sheet, and λ represents the distance from the upper edge of the laminated sheet to the neutral axis. In formula (1), the bending stiffness is calculated by regarding the laminated sheet as a single layer. Specifically, the bending stiffness is measured by the method described in the examples below.
The tensile modulus in formula (1) is measured by the method described later.

As can be seen from formula (1), the bending stiffness can be increased by increasing the modulus of elasticity of at least one of the spacer layer 10 and the adhesive layer 20, or by increasing the thickness of at least one of the spacer layer 10 and the adhesive layer 20. On the other hand, the bending stiffness can be decreased by decreasing the modulus of elasticity of at least one of the spacer layer 10 and the adhesive layer 20, or by decreasing the thickness of at least one of the spacer layer 10 and the adhesive layer 20.

The elastic modulus of the laminated sheet is preferably 1 GPa or more, more preferably 1.5 GPa or more, and even more preferably 2 GPa or more, so that the laminated sheet of the spacer layer and the adhesive layer can exhibit better pick-up properties when peeled off from the dicing tape 30.
The elastic modulus of the laminate sheet may be 5 GPa or less, or 4 GPa or less.

The above elastic modulus is measured as follows. A measurement sample with a length of 40 mm and a width of 10 mm is cut out from a laminated sheet in which the spacer layer 10 and the adhesive layer 20 are laminated, and the tensile storage modulus is measured at -30°C to 300°C using a solid viscoelasticity measuring device. The measurement conditions are a frequency of 1 Hz, a heating rate of 10°C/min, and a chuck distance of 20.0 mm. The measured value of the storage modulus at room temperature (preferably 25°C) is used as the above elastic modulus.

The above elastic modulus can be increased by using a material with a higher elastic modulus as the material constituting at least one of the spacer layer 10 and the adhesive layer 20, or by increasing the content of the material with the higher elastic modulus in at least one of the spacer layer 10 and the adhesive layer 20. On the other hand, the above elastic modulus can be decreased by using a material with a lower elastic modulus as the material constituting at least one of the spacer layer 10 and the adhesive layer 20, or by increasing the content of the material with the lower elastic modulus in at least one of the spacer layer 10 and the adhesive layer 20.

The temperature at which the above elastic modulus is measured is room temperature, which is the temperature at which the spacer-attached dicing adhesive film 1 is used. Specifically, the temperature at which the laminated sheet in which the spacer layer 10 and the adhesive layer 20 are laminated is broken into small pieces (see Figures 4B and 4C), and the small pieces of the laminated sheet are peeled off from the adhesive layer 32 of the dicing tape 30 and picked up (see Figure 4D) corresponds to the temperature at which the above elastic modulus is measured.

The peel strength between the adhesive layer 20 and the spacer layer 10 is preferably 0.1 N/20 mm or more. The peel strength may be 0.5 N/20 mm or less.
The peel strength is measured at room temperature using a test sample having a length of 120 mm and a width of 25 mm. The peel strength is a value measured under the measurement conditions of a peel speed of 300 mm/min, a peel angle of 90 degrees, and a measurement temperature of 25° C. Specifically, the peel strength is measured by the method described in the examples below.

In order to increase the peeling force, for example, the surface of the spacer layer 10 that is in direct contact with the adhesive layer 20 may be subjected to a plasma surface treatment in advance, or may be subjected to a cleaning treatment by wiping with alcohol or the like. On the other hand, in order to decrease the peeling force, for example, the surface of the spacer layer 10 may be subjected to a release treatment with silicone, and the release-treated surface may be superimposed on the adhesive layer 20.

The thickness (average thickness) of the laminate sheet (spacer layer and adhesive layer) may be 30 μm or more and 300 μm or less, or 40 μm or more and 200 μm or less.
The thickness of the laminated sheet is calculated by averaging the thickness measurements at at least five randomly selected points.

The spacer-attached dicing adhesive film 1 of this embodiment may be provided with a release tape that covers one side of the spacer layer 10 (the side where the spacer layer 10 does not overlap the adhesive layer 20) before use. The release tape is used to protect the spacer layer 10, and is peeled off, for example, immediately before use.

Next, we will explain in detail the dicing tape 30 attached to the adhesive layer 20.

<Dicing tape of dicing adhesive film with spacer>
The dicing tape 30 is usually in a band shape, stretched over an annular frame having an inner diameter slightly larger than the silicon wafer to be cut, and then cut for use.

The dicing tape 30 includes a base layer 31 and an adhesive layer 32 superimposed on the base layer 31.

The base layer 31 may have a single-layer structure or a laminated structure.
The base layer 31 supports the pressure-sensitive adhesive layer 32. The base layer 31 contains a resin. Examples of the resin contained in the base layer 31 include polyolefins (polypropylene (PP), high density polyethylene (HDPE), low density polyethylene, α-olefins, etc.), ethylene-vinyl acetate copolymers (EVA), ethylene-methyl acrylate (EMA), ethylene-ethyl acrylate (EEA), ethylene-methyl methacrylate (EMMA), styrene-butadiene rubber (SBR), hydrogenated styrene thermoplastic elastomers (SEBS), styrene-ethylene-propylene-styrene block copolymers (SEPS), polyesters, polyurethanes, polycarbonates, polyether ether ketones, polyimides, polyetherimides, polyamides, wholly aromatic polyamides, polyvinyl chloride, polyvinylidene chloride, polyphenyl sulfide, fluororesins, cellulose resins, silicone resins, and ionomer resins.

The base layer 31 may contain one type of the above-mentioned resin, or may contain two or more types of the above-mentioned resin.
In addition, when the adhesive layer 32 is cured by ultraviolet light as described below, the base layer 31 is preferably configured to be ultraviolet-transmitting.

The substrate layer 31 may be obtained by non-stretch molding or by stretch molding. A substrate layer 31 obtained by stretch molding is preferred.

The thickness (total thickness) of the base layer 31 is preferably 55 μm or more and 195 μm or less, more preferably 55 μm or more and 190 μm or less, even more preferably 55 μm or more and 170 μm or less, and optimally 60 μm or more and 160 μm or less.
The thickness of the base layer 31 can be determined, for example, by measuring the thickness at five randomly selected points using a dial gauge (Model R-205, manufactured by PEACOCK) and calculating the arithmetic average of these thicknesses.

The base layer 31 is preferably made of a resin film.
The surface of the base layer 31 may be subjected to a surface treatment in order to enhance adhesion with the pressure-sensitive adhesive layer 32. Examples of the surface treatment that may be used include oxidation treatment by chemical or physical methods such as chromate treatment, ozone exposure, flame exposure, high-voltage shock exposure, and ionizing radiation treatment. In addition, the base layer 31 may be subjected to a coating treatment using a coating agent such as an anchor coating agent, a primer, or an adhesive.

The back side of the base layer 31 (the side on which the adhesive layer 32 is not overlapped) may be subjected to a release treatment using a release agent (release agent) such as a silicone-based resin or a fluorine-based resin in order to impart releasability.
The base layer 31 is preferably a light-transmitting (ultraviolet ray-transmitting) resin film or the like, since this allows active energy rays such as ultraviolet ray to be applied to the pressure-sensitive adhesive layer 32 from the rear side.

The dicing tape 30 may be provided with a release tape that covers one side of the adhesive layer 32 (the side where the adhesive layer 32 does not overlap the base layer 31) before use. When the adhesive layer 20, which has an area smaller than the adhesive layer 32, is arranged so as to be contained within the adhesive layer 32, the release tape is arranged so as to cover both the adhesive layer 32 and the adhesive layer 20. The release tape is used to protect the adhesive layer 32, and is peeled off before the adhesive layer 20 is attached to the adhesive layer 32.

As the release tape, for example, a plastic film or paper that has been surface-treated with a release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide-based release agent can be used.
In addition, examples of the release tape that can be used include films made of fluorine-based polymers such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer; films made of polyolefins such as polyethylene and polypropylene; and films made of polyesters such as polyethylene terephthalate (PET).
As the release tape, for example, a plastic film or paper whose surface is coated with a release agent such as a fluorine-based release agent or a long-chain alkyl acrylate-based release agent can be used.

In the present embodiment, the pressure-sensitive adhesive layer 32 contains, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator.
The pressure-sensitive adhesive layer 32 may have a thickness of 5 μm or more and 40 μm or less. The shape and size of the pressure-sensitive adhesive layer 32 are usually the same as the shape and size of the base layer 31.

The acrylic polymer has at least an alkyl (meth)acrylate structural unit, a hydroxyl group-containing (meth)acrylate structural unit, and a polymerizable group-containing (meth)acrylate structural unit in the molecule. The structural units are units that constitute the main chain of the acrylic polymer. Each side chain in the acrylic polymer is included in each structural unit that constitutes the main chain.
In this specification, the term "(meth)acrylate" refers to at least one of methacrylate (methacrylic acid ester) and acrylate (acrylic acid ester). Similarly, the term "(meth)acrylic acid" refers to at least one of methacrylic acid and acrylic acid.

In the acrylic polymer contained in the pressure-sensitive adhesive layer 32, the above-mentioned structural units can be confirmed by NMR analysis such as ¹ H-NMR and ¹³ C-NMR, pyrolysis GC/MS analysis, infrared spectroscopy, etc. The molar ratio of the above-mentioned structural units in the acrylic polymer is usually calculated from the blending amount (charge amount) when the acrylic polymer is polymerized.

The above alkyl (meth)acrylate structural unit is derived from an alkyl (meth)acrylate monomer. In other words, the molecular structure after the alkyl (meth)acrylate monomer is polymerized is the alkyl (meth)acrylate structural unit. The term "alkyl" refers to the hydrocarbon moiety ester-bonded to (meth)acrylic acid.
The hydrocarbon portion of the alkyl portion in the structural unit of the alkyl (meth)acrylate may be a saturated hydrocarbon or an unsaturated hydrocarbon.
It is preferable that the alkyl portion does not contain a polar group containing oxygen (O) or nitrogen (N). This can prevent the polarity of the alkyl polymer from increasing excessively. Therefore, the pressure-sensitive adhesive layer 32 is prevented from having excessive affinity for the adhesive layer 20. Therefore, the dicing tape 30 can be more satisfactorily peeled off from the adhesive layer 20. The number of carbon atoms in the alkyl portion may be 6 or more and 10 or less.

Examples of constituent units of alkyl (meth)acrylate include hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n- or iso-nonyl (meth)acrylate, and decyl (meth)acrylate.

The acrylic polymer has a hydroxyl group-containing (meth)acrylate structural unit, and the hydroxyl group of such a structural unit easily reacts with an isocyanate group.
By allowing the acrylic polymer having a hydroxyl group-containing (meth)acrylate structural unit and the isocyanate compound to coexist in the pressure-sensitive adhesive layer 32, the pressure-sensitive adhesive layer 32 can be appropriately cured. This allows the acrylic polymer to be sufficiently gelled. Thus, the pressure-sensitive adhesive layer 32 can exhibit its adhesive performance while maintaining its shape.

The structural unit of the hydroxyl group-containing (meth)acrylate is preferably a structural unit of a hydroxyl group-containing C2-C4 alkyl (meth)acrylate. The term "C2-C4 alkyl" refers to the number of carbon atoms in the hydrocarbon moiety that is ester-bonded to the (meth)acrylic acid. In other words, the hydroxyl group-containing C2-C4 alkyl (meth)acrylate monomer refers to a monomer in which (meth)acrylic acid is ester-bonded to an alcohol having 2 to 4 carbon atoms (usually a dihydric alcohol).
The hydrocarbon portion of the C2-C4 alkyl is usually a saturated hydrocarbon. For example, the hydrocarbon portion of the C2-C4 alkyl is a linear saturated hydrocarbon or a branched saturated hydrocarbon. It is preferable that the hydrocarbon portion of the C2-C4 alkyl does not contain a polar group containing oxygen (O), nitrogen (N), or the like.

Examples of structural units of hydroxyl-containing C2-C4 alkyl (meth)acrylate include structural units of hydroxybutyl (meth)acrylate, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxy n-butyl (meth)acrylate, or hydroxy iso-butyl (meth)acrylate. In the structural unit of hydroxybutyl (meth)acrylate, the hydroxyl group (-OH group) may be bonded to the carbon (C) at the end of the hydrocarbon portion, or to a carbon (C) other than the end of the hydrocarbon portion.

The acrylic polymer contains a structural unit of a polymerizable group-containing (meth)acrylate having a polymerizable unsaturated double bond in the side chain.
Since the acrylic polymer contains a structural unit of a polymerizable group-containing (meth)acrylate, the pressure-sensitive adhesive layer 32 can be cured by irradiation with active energy rays (such as ultraviolet rays) before the pick-up step. In particular, the irradiation with active energy rays such as ultraviolet rays generates radicals from the photopolymerization initiator, and the acrylic polymers can be crosslinked by the action of these radicals. This allows the adhesion of the pressure-sensitive adhesive layer 32 before irradiation to be reduced by irradiation. Then, the adhesive layer 20 can be peeled off well from the pressure-sensitive adhesive layer 32.
The active energy rays include ultraviolet rays, radioactive rays, and electron beams.

Specifically, the structural unit of the polymerizable group-containing (meth)acrylate may have a molecular structure in which an isocyanate group of an isocyanate group-containing (meth)acrylate monomer is urethane-bonded to a hydroxyl group in the structural unit of the hydroxyl group-containing (meth)acrylate described above.

The structural unit of the polymerizable group-containing (meth)acrylate having a polymerizable group can be prepared after polymerization of the acrylic polymer. For example, after copolymerization of an alkyl (meth)acrylate monomer with a hydroxyl group-containing (meth)acrylate monomer, the hydroxyl group in a part of the structural unit of the hydroxyl group-containing (meth)acrylate and the isocyanate group of the isocyanate group-containing polymerizable monomer are reacted to form a urethane reaction, thereby obtaining the structural unit of the polymerizable group-containing (meth)acrylate.

The above-mentioned isocyanate group-containing (meth)acrylate monomer preferably has one isocyanate group and one (meth)acryloyl group in the molecule. An example of such a monomer is 2-isocyanatoethyl (meth)acrylate.

The adhesive layer 32 of the dicing tape 30 in this embodiment further contains an isocyanate compound. A part of the isocyanate compound may be in a state after being reacted by a urethane reaction or the like.
The isocyanate compound has a plurality of isocyanate groups in its molecule. The isocyanate compound has a plurality of isocyanate groups in its molecule, which allows a crosslinking reaction between the acrylic polymers in the pressure-sensitive adhesive layer 32 to proceed. In more detail, one isocyanate group of the isocyanate compound is reacted with a hydroxyl group of an acrylic polymer, and the other isocyanate group is reacted with a hydroxyl group of another acrylic polymer, allowing a crosslinking reaction via the isocyanate compound to proceed.

Examples of isocyanate compounds include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, and araliphatic diisocyanates.

Further examples of isocyanate compounds include polymerized polyisocyanates such as diisocyanate dimers and trimers, and polymethylene polyphenylene polyisocyanates.

In addition, the isocyanate compound may be, for example, a polyisocyanate obtained by reacting an excess amount of the above-mentioned isocyanate compound with an active hydrogen-containing compound. Examples of the active hydrogen-containing compound include an active hydrogen-containing low molecular weight compound and an active hydrogen-containing high molecular weight compound.
As the isocyanate compound, allophanated polyisocyanate, biuretized polyisocyanate, etc. can also be used.
The above isocyanate compounds may be used alone or in combination of two or more.

The above-mentioned isocyanate compound is preferably a reaction product of an aromatic diisocyanate and an active hydrogen-containing low molecular weight compound. The reaction rate of the isocyanate group in the reaction product of an aromatic diisocyanate is relatively slow, so that the pressure-sensitive adhesive layer 32 containing such a reaction product is prevented from being excessively hardened. The above-mentioned isocyanate compound is preferably one having three or more isocyanate groups in the molecule.

The polymerization initiator contained in the adhesive layer 32 is a compound that can initiate a polymerization reaction by the applied heat or light energy. By containing the polymerization initiator in the adhesive layer 32, a crosslinking reaction between acrylic polymers can be promoted when heat energy or light energy is applied to the adhesive layer 32. In detail, a polymerization reaction between polymerizable groups between acrylic polymers having structural units of polymerizable group-containing (meth)acrylate can be initiated to harden the adhesive layer 32. This reduces the adhesive strength of the adhesive layer 32, and the adhesive layer 20 can be easily peeled off from the hardened adhesive layer 32 in the pick-up process.
As the polymerization initiator, for example, a photopolymerization initiator or a thermal polymerization initiator is used. As the polymerization initiator, a general commercially available product can be used.

The adhesive layer 32 may further contain other components in addition to the components described above. Examples of the other components include tackifiers, plasticizers, fillers, antioxidants, antioxidants, UV absorbers, light stabilizers, heat stabilizers, antistatic agents, surfactants, and light release agents. The types and amounts of the other components used may be appropriately selected depending on the purpose.

The spacer-attached dicing adhesive film 1 of this embodiment is preferably used to embed a semiconductor chip w' with an adhesive layer 20 when manufacturing a chip-embedded type semiconductor integrated circuit (FOD [Film On Die] type semiconductor integrated circuit). In detail, the spacer-attached dicing adhesive film 1 is preferably used by adhering the adhesive layer 20 to the substrate Z so as to embed the semiconductor chip w' with the adhesive layer 20 (see FIG. 1C, FIG. 5A, etc.).
In this embodiment, the spacer-attached dicing adhesive film 1 having a spacer layer 10 made of resin or the like can be used for the above-mentioned applications, and therefore the manufacturing process of the semiconductor integrated circuit can be shortened compared to using a conventional processing film in which the spacer layer is a Si wafer. Specifically, it is not necessary to carry out a series of steps of attaching a backgrind tape to the Si wafer and processing the Si wafer to a desired thickness by backgrinding. In addition, the spacer layer can be produced without being affected by a shortage of Si wafers, and the spacer layer can be produced from a relatively inexpensive resin.
Alternatively, the spacer-attached dicing adhesive film 1 of this embodiment may be used with the adhesive layer 20 adhered to the substrate Z in order to secure space for stacking the memory NAND chip w″ above the control NAND chip w′ when manufacturing a wire-embedded semiconductor integrated circuit (FOW [Film On Wire] type semiconductor integrated circuit) (see, for example, FIGS. 5B to 5E). In this case, the spacer-attached dicing adhesive film 1 may be used with the adhesive layer 20 adhered to the substrate Z so that the bonding wire L is embedded in the adhesive layer 20. This has the advantage of being able to shorten the manufacturing process of the semiconductor integrated circuit for the same reasons as those described above, and also has the advantage of being able to produce the spacer layer without being affected by a shortage in supply of Si wafers.

Next, we will explain the manufacturing method of the spacer-equipped dicing adhesive film 1 of this embodiment.

<Method of manufacturing dicing adhesive film with spacer>
The method for producing the spacer-equipped dicing adhesive film 1 of this embodiment is as follows:
A step of fabricating a spacer layer 10;
A step of preparing an adhesive layer 20;
A step of preparing a dicing tape 30;
The method includes a step of overlapping the manufactured spacer layer 10, adhesive layer 20, and dicing tape 30.

(Step of Producing Spacer Layer)
The process of producing the spacer layer 10 may include, for example, a resin composition preparation process of preparing a resin composition for forming the spacer layer 10, and a spacer layer formation process of forming the spacer layer 10 from the resin composition.
On the other hand, a commercially available resin film may be adopted as the spacer layer 10 .

(Step of Producing Adhesive Layer)
The step of producing the adhesive layer 20 includes:
A resin composition preparation step of preparing a resin composition for forming the adhesive layer 20;
and an adhesive layer forming step of forming an adhesive layer 20 from a resin composition.

In the resin composition preparation process, for example, an epoxy resin, an epoxy resin curing catalyst, an acrylic resin, a phenolic resin, a solvent, etc. are mixed and each resin is dissolved in the solvent to prepare a resin composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Commercially available products can be used as these resins.

In the adhesive layer forming step, for example, the resin composition prepared as described above is applied to a release sheet. The application method is not particularly limited, and for example, a general application method such as roll coating, screen coating, gravure coating, etc. is adopted. Next, if necessary, the applied composition is solidified by a desolvation treatment, a curing treatment, etc., to form the adhesive layer 20.
In the adhesive layer forming step, the adhesive layer 20 overlapping the spacer layer 10 may be formed by applying the resin composition prepared as described above onto the spacer layer 10 .

(Process for producing dicing tape)
The process of producing the dicing tape 30 includes the following steps:
A synthesis step of synthesizing an acrylic polymer;
A pressure-sensitive adhesive layer preparation step of preparing a pressure-sensitive adhesive layer 32 by volatilizing a solvent from a pressure-sensitive adhesive composition containing the above-mentioned acrylic polymer, an isocyanate compound, a polymerization initiator, a solvent, and other components appropriately added depending on the purpose;
a base layer preparation step of preparing a base layer 31;
and a bonding step of bonding the adhesive layer 32 and the base layer 31 together.

In the synthesis step, for example, a C9 to C11 alkyl (meth)acrylate monomer and a hydroxyl group-containing (meth)acrylate monomer are radically polymerized to synthesize an acrylic polymer intermediate.
The radical polymerization can be carried out by a general method. For example, the above-mentioned monomers are dissolved in a solvent, stirred while heating, and a polymerization initiator is added to synthesize an acrylic polymer intermediate. In order to adjust the molecular weight of the acrylic polymer, the polymerization may be carried out in the presence of a chain transfer agent.
Next, some of the hydroxyl groups of the hydroxyl group-containing (meth)acrylate structural units contained in the acrylic polymer intermediate are bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer by a urethane reaction, whereby some of the hydroxyl group-containing (meth)acrylate structural units become polymerizable group-containing (meth)acrylate structural units.
The urethane reaction can be carried out by a general method. For example, the acrylic polymer intermediate and the isocyanate group-containing polymerizable monomer are stirred while being heated in the presence of a solvent and a urethane catalyst. This allows the isocyanate group of the isocyanate group-containing polymerizable monomer to be urethane-bonded to a part of the hydroxyl groups of the acrylic polymer intermediate.

In the adhesive layer preparation process, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare an adhesive composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Next, the adhesive composition is applied to a release sheet. As the application method, for example, a general application method such as roll coating, screen coating, or gravure coating is adopted. The applied composition is subjected to a solvent removal process, a solidification process, or the like to solidify the applied adhesive composition, thereby preparing the adhesive layer 32.

In the substrate layer preparation process, the substrate layer 31 can be prepared by film formation using a general method. Examples of the film formation method include a calendar film formation method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, and a dry lamination method. A co-extrusion molding method may also be used. Note that a commercially available film or the like may also be used as the substrate layer 31.

In the lamination step, the pressure-sensitive adhesive layer 32 overlapping the release sheet is laminated on the base layer 31. The release sheet may remain overlapping the pressure-sensitive adhesive layer 32 until use.
In addition, in order to promote the reaction between the crosslinking agent and the acrylic polymer and also between the crosslinking agent and the surface portion of the base material layer 31, an aging treatment process may be carried out for 48 hours in an environment of 50°C after the lamination process.

Through these steps, the dicing tape 30 can be manufactured.

(Step of overlapping the adhesive layer with the spacer layer attached and the dicing tape)
In the step of overlapping the adhesive layer 20 and the dicing tape 30, the adhesive layer 20 is attached to the pressure-sensitive adhesive layer 32 of the dicing tape 30 manufactured as described above.

In this bonding, the release sheets are peeled off from the adhesive layer 32 of the dicing tape 30 and from the adhesive layer 20, respectively, and the two are bonded together so that the adhesive layer 20 and the adhesive layer 32 are in direct contact with each other. For example, they can be bonded together by pressure bonding. The temperature during bonding is not particularly limited, and is, for example, 30°C to 50°C, and preferably 35°C to 45°C. The linear pressure during bonding is not particularly limited, but is preferably 0.1 kgf/cm to 20 kgf/cm, and more preferably 1 kgf/cm to 10 kgf/cm.

<Production method of dicing adhesive film with spacer (specific example)>
2 and 3, the spacer-attached dicing adhesive film 1 of this embodiment has a laminated sheet of a spacer layer 10 and an adhesive layer 20 superimposed on one side of a long sheet-like dicing tape 30. The laminated sheet (spacer layer 10 and adhesive layer 20) superimposed on the dicing tape 30 is circular when viewed in the thickness direction, and a plurality of laminated sheets are arranged in a row along the longitudinal direction of the dicing tape 30. The spacer-attached dicing adhesive film 1 of this embodiment can be manufactured, for example, using a peeling tape H and a transfer tape T as follows.

The spacer-attached dicing adhesive film 1 can be manufactured, for example, by using the devices (I, I', I'') shown in FIGS. 7A, 8A, and 9A.
First, as shown in Fig. 6A, the above-mentioned resin composition is applied onto a spacer layer 10 (e.g., a resin film), and the solvent is evaporated from the resin composition to prepare an adhesive layer 20 overlapping the spacer layer 10. Next, a release tape H is attached to the adhesive layer 20, and a strip-shaped laminate sheet with the release tape H is prepared as shown in Fig. 6B. Note that a similar laminate sheet can also be prepared by applying the above-mentioned resin composition to the release tape H, and overlapping the spacer layer 10 on the adhesive layer 20 prepared in the same manner.
Next, the laminated sheet of the spacer layer 10 and the adhesive layer 20 is set in an apparatus as shown in Fig. 7A. At this time, the laminated sheet is placed with the release tape H facing down as shown in Fig. 7B. As the laminated sheet passes through the apparatus, the transfer tape T is placed on top of the spacer layer 10. At this stage, the sheet in which the release tape H, the spacer layer 10, the adhesive layer 20, and the transfer tape T are bonded together is temporarily wound up.
Further, the sheets once bonded together are set in a device as shown in FIG. 8A. At this time, as shown in FIG. 8B, the transfer tape T is placed on the lower side. While the bonded sheets are passed through the device, the release tape H and the laminated sheet are punched into a circular shape (predetermined shape) by punching. Next, the release tape H other than the part punched into a circular shape (the release tape H of the peripheral part other than the circular part) is removed by rolling up. After that, the removal tape S is applied while the remaining part of the bonded sheets is moved downstream by the device. By rolling up the removal tape S once applied, unnecessary parts of the laminated sheet are removed so that a thin disk-shaped laminated sheet remains on the transfer tape T (see FIG. 8C). Next, a dicing tape 30 is superimposed on the multiple thin spacer layers 10 so as to cover the multiple laminated sheets that are now arranged at a distance from each other (see FIG. 8D). At this time, the adhesive layer 32 of the dicing tape 30 is applied so as to directly contact the adhesive layer 20. At this stage, the sheet in which the spacer layer 10, the adhesive layer 20, and the transfer tape T are bonded together is once rolled up. This results in a state in which the transfer tape T is attached to the spacer-attached dicing adhesive film 1, which is a laminate of the dicing tape 30, the adhesive layer 20, and the spacer layer 10. This state may be the final target, but in order to remove the transfer tape T, it may be wound up once and the following operation may be further carried out.
In addition, the spacer-attached dicing adhesive film 1 (with transfer tape T) that has been wound up is set in an apparatus as shown in Fig. 9A. At this time, as shown in Fig. 9B, the transfer tape T is placed on the upper side and the dicing tape 30 is placed on the lower side. The transfer tape T is removed while the spacer-attached dicing adhesive film 1 is passed through the apparatus (see Fig. 9C). Furthermore, in order to protect the exposed spacer layer 10, a peel tape H may be placed on the spacer layer 10 (see Fig. 9D).

7A, 8A, and 9A, the feeding direction when the long sheet is supplied to each device and the winding direction when the long sheet is collected are not particularly limited. In detail, the long sheet arranged on the most upstream side of each device and wound up may be fed so that the inner peripheral surface faces upward, or may be fed so that the outer peripheral surface faces upward. Also, the long sheet arranged on the most downstream side of each device and wound up may be collected so that the upper surface faces the inner peripheral side, or may be collected so that the upper surface faces the outer peripheral side.
The spacer-attached dicing adhesive film 1 manufactured by the above-mentioned device may be further processed. For example, the spacer-attached dicing adhesive film 1 may be subjected to a slitting process for removing both ends in the width direction according to the standard width of the product (FIG. 10A), and then a precutting process for punching the dicing tape 30 from above into a predetermined shape with a punching device (not shown) that is slightly larger (for example, 1.1 to 1.4 times) than the circular punched portion (the punched portion of the adhesive layer 20 and the spacer layer 10) and removing unnecessary dicing tape 30 (see FIG. 10B).

The spacer-attached dicing adhesive film 1 manufactured as described above is used, for example, as an auxiliary tool for manufacturing semiconductor integrated circuits. The spacer-attached dicing adhesive film 1 is used particularly in the second process described below. Specific examples of its use are described below.

<Method of using spacer-equipped dicing adhesive film when manufacturing semiconductor integrated circuits>
A method for manufacturing a semiconductor integrated circuit generally includes a process of cutting out chips from a semiconductor wafer having a circuit surface formed thereon, and assembling the chips.
Such a process may, for example,
A first step of cutting out a controller chip w′ for control from a semiconductor wafer (bare wafer) and fixing it to a surface of a substrate Z;
a second step of cutting out a small piece of the spacer layer 10 with the adhesive layer 20 attached from the laminated sheet in which the adhesive layer 20 and the spacer layer 10 are laminated, and fixing it to the surface of the substrate Z, thereby forming a base of the spacer layer 10 for stacking a plurality of storage NAND chips w″;
and a third step of cutting out storage NAND chips w′ from a semiconductor wafer (bare wafer) and stacking a plurality of storage NAND chips w″ on the spacer layer 10.
The spacer-attached dicing adhesive film 1 of this embodiment is used, for example, in the above-mentioned second step.

The first step includes a step of forming a groove in the semiconductor wafer and then grinding the semiconductor wafer to thin it so as to fix the controller chip w' to the surface of the adherend (substrate Z) in order to process the semiconductor wafer into a chip w' (die) by a fracturing process, a step of attaching one side of the thinned semiconductor wafer (for example, the side opposite to the circuit side) to a dicing tape 30 to fix the semiconductor wafer to the dicing tape 30, a step of widening the gap between the half-cut semiconductor chips to break the semiconductor wafer into small chips, a step of picking up and removing the semiconductor chip w' (die) with the die bond layer d' attached, and a step of adhering (die bonding) the semiconductor chip w' (die) with the die bond layer d' attached to the adherend (see FIG. 1A).

When carrying out the following steps in the second process, the dicing tape 30 (dicing adhesive film with spacers) of this embodiment is used as a manufacturing aid.
The second step includes, for example, a step of attaching a dicing ring R to the dicing tape 30 of the spacer-attached dicing adhesive film 1 in order to fix the spacer layer 10 and the adhesive layer 20 to the surface of the substrate (substrate Z) (see FIG. 4A); a step of subjecting the adhesive layer 20 and the spacer layer 10 to blade dicing processing using a dicing saw B to cut them into small pieces (dies) (see FIGS. 4B and 4C); a step of peeling and picking up the small pieces of the spacer layer 10 with the adhesive layer 20 attached thereto from the adhesive layer 32 of the dicing tape 30 using an adsorption jig J (see FIG. 4D); and a step of adhering the spacer layer 10 with the adhesive layer 20 attached thereto to the substrate (substrate Z) (see FIG. 1B).

In the third step, in order to stack the memory NAND chips w" multiple times on the spacer layer 10, for example, similar to the first step, the memory NAND chips w" are picked up and attached to the substrate (spacer layer 10), and the memory NAND chips w" are further stacked (see FIG. 1C).

In recent years, with the further advancement of integration technology in the semiconductor industry, the capacity per unit area of a NAND chip is increasing. Accordingly, for the same capacity, the size of the NAND chip is becoming smaller. For example, in a type of semiconductor integrated circuit in which a storage NAND chip w" is stacked on a control controller chip w', if the size of the storage NAND chip w" becomes smaller, it may become difficult to embed the control controller chip w' in the storage NAND chip w", making it difficult to assemble the semiconductor integrated circuit.
On the other hand, in order to secure a space for stacking the storage NAND chips w″, the dicing adhesive film 1 with spacers of this embodiment can be used.
The spacer-attached dicing adhesive film 1 of this embodiment can be used to divide the above-mentioned laminated sheet into small pieces, peel the small pieces of the laminated sheet from the dicing tape 30, and pick them up, in the same manner as the dicing die bond film used when producing semiconductor chips from a bare wafer. The picked-up laminated sheet is then adhered to an adherend such as a substrate Z, and a memory NAND chip w″ is stacked on the spacer layer 10 of the laminated sheet.

The shape of the semiconductor integrated circuit to be manufactured is not limited to the shape shown in FIG. 1C, but may be any of the shapes shown in FIGS. 5A to 5E, for example.

The dicing adhesive film with spacers of this embodiment is as exemplified above, but the present invention is not limited to the dicing adhesive film with spacers exemplified above.
That is, various forms used in general spacer-attached dicing adhesive films can be adopted as long as they do not impair the effects of the present invention.

The matters disclosed in this specification include the following.
(1) A laminated sheet having an adhesive layer that is adhered to an adherend and a spacer layer that overlaps the adhesive layer;
a dicing tape that overlaps the adhesive layer of the laminated sheet and holds the laminated sheet;
A dicing adhesive film with spacers, wherein the bending rigidity of the laminated sheet at room temperature is 0.05 N· ^mm2 or more.
(2)
The spacer-attached dicing adhesive film according to (1) above, wherein the elastic modulus of the laminated sheet is 1 GPa or more.
(3)
The dicing adhesive film with spacers according to (2) above, wherein the peel strength between the adhesive layer and the spacer layer is 0.1 N/20 mm or more.
(4)
The dicing adhesive film with spacers according to any one of (1) to (3) above, wherein the thickness of the spacer layer is 3 μm or more and 300 μm or less.
(5)
The spacer-attached dicing adhesive film according to any one of (1) to (4) above, wherein the thickness of the adhesive layer is 10 μm or more and 200 μm or less.
(6)
The material of the spacer layer is at least one selected from the group consisting of polyimide, polyamideimide, polyester, polybenzimidazole, polyetherimide, polyphenylene sulfide, and polyether ether ketone. A dicing adhesive film with spacers according to any one of (1) to (5) above.
(7)
The dicing adhesive film with spacers according to any one of (1) to (6) above, wherein the adhesive layer contains a thermosetting resin and a thermoplastic resin.
(8)
The dicing adhesive film with spacers according to (7) above, wherein the adhesive layer further contains a filler.
(9)
The dicing adhesive film with spacers according to (8) above, wherein the adhesive layer has a filler content of 30% by mass or more and 70% by mass or less relative to the total mass of the adhesive layer.
(10)
The spacer-attached dicing adhesive film according to any one of (1) to (9) above, wherein the pressure-sensitive adhesive layer of the dicing tape contains an acrylic polymer, an isocyanate compound, and a polymerization initiator.
(11)
The dicing adhesive film with spacers according to the above (10), wherein the acrylic polymer contained in the pressure-sensitive adhesive layer contains a structural unit of a polymerizable group-containing (meth)acrylate having a polymerizable unsaturated double bond in a side chain.
(12)
A dicing adhesive film with spacer according to any one of (1) to (11) above, which is used for embedding a semiconductor chip when manufacturing a chip-embedded type semiconductor integrated circuit, or for securing space for stacking a memory semiconductor chip on a control semiconductor chip when manufacturing a wire-embedded type semiconductor integrated circuit.

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

(Examples 1 to 6 and Comparative Example 1)
A laminate sheet of a spacer layer and an adhesive layer was produced as follows. The adhesive layer of this laminate sheet was attached to a dicing tape to produce dicing adhesive films with spacers having the configurations shown in Table 1.

<Spacer Layer>
The following resin film was prepared as the spacer layer.
・Polyimide film A (thickness 75 μm)
(Product name: Kapton 300V, manufactured by Toray DuPont)
・Polyimide film B (thickness 25 μm)
(Product name: Kapton 100H, manufactured by Toray DuPont)
・Polyamideimide film (thickness 4 μm)
(Product name: "Mictron #4Y-GE10" manufactured by Toray Industries, Inc.)
Para-type aromatic polyamide (aramid) film, polyethylene terephthalate film A (50 μm thick, silicone-treated on one side)
(The untreated surface was laminated to the adhesive layer)
(Product name: Diafoil MRA50, manufactured by Mitsubishi Chemical Corporation)
・Polyethylene terephthalate film B (thickness 50 μm, one side silicone treated)
(The silicone-treated surface was attached to the adhesive layer.)
(Product name: Diafoil MRA50, manufactured by Mitsubishi Chemical Corporation)

<Preparation of adhesive layer>
The following raw materials were added to methyl ethyl ketone and mixed to obtain a composition for adhesive layer. Details of each raw material are shown below.
Acrylic acid ester polymer solution 100 parts by weight Product name "Teisan Resin SG-70L" (solid content concentration 12.8% by weight)
Epoxy resin manufactured by Nagase ChemteX Corporation: 1.7 parts by weight Product name "Epikote YL980" Epoxy resin manufactured by Mitsubishi Chemical Corporation: 13 parts by weight Product name "EPICLON N-665-EXP-S" Phenol resin (hardener) manufactured by DIC Corporation: 15 parts by weight Product name "MEHC-7851SS" Silica organic solvent slurry manufactured by Meiwa Kasei Co., Ltd.: 47 parts by weight (containing 60% by weight of powder)
Product name: "SO-E2" (powder pre-dispersed in MEK)
Admatechs Co., Ltd. curing catalyst 0.085 parts by weight
Product name: "Curesol 2PHZ" manufactured by Shikoku Kasei Co., Ltd. Dilution solvent: 50 parts by weight MEK (methyl ethyl ketone)
Next, the adhesive layer composition was applied to one side of the coating substrate using an applicator. The coating was performed so that the thickness after drying was 120 μm, and then the solvent was evaporated from the adhesive layer composition by drying at 120° C. for 2 minutes. In this way, an adhesive layer overlapping the coating substrate was obtained.
Coating substrate (release sheet) Product name "PET38" manufactured by Fujiko Co., Ltd. A spacer layer was attached to the exposed surface of this adhesive layer.

<Adhesive layer of dicing tape>
(Preparation of Pressure-Sensitive Adhesive Layer (Pressure-Sensitive Adhesive Composition))
The following raw materials were prepared:
・2EHA (2-ethylhexyl acrylate): 100 parts by mass ・HEA (2-hydroxyethyl acrylate): 20 parts by mass ・AIBN (2,2'-azobisisobutyronitrile): appropriate amount ・Polymerization solvent (toluene): amount to make the monomer concentration about 55% by mass The above raw materials were placed in a round-bottomed separable flask of a polymerization experimental apparatus equipped with a round-bottomed separable flask (volume 1 L), a thermometer, a nitrogen inlet tube, and a stirrer. While stirring, nitrogen gas was introduced into the round-bottomed separable flask, and a polymerization reaction was carried out at 60°C for 10 hours to prepare an intermediate composition.
After the intermediate composition was cooled to room temperature, the following raw materials were added to 100 parts by mass of the intermediate composition.
2-Methacryloyloxyethyl isocyanate (raw material name "Karenz MOI", manufactured by Showa Denko KK): 1.4 parts by mass Dibutyltin dilaurate IV (manufactured by Wako Pure Chemical Industries, Ltd.): 0.1 parts by mass The mixture was stirred at 50° C. for 60 hours in an air atmosphere to obtain an acrylic polymer composition.
Finally, the following raw materials were added to 100 parts by mass of the solid content of the above acrylic polymer composition to obtain a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer.
Isocyanate compound (raw material name "Coronate L", manufactured by Tosoh Corporation): 1.1 parts by mass Photopolymerization initiator (raw material name "Irgacure 184", manufactured by IGM Resins): 3 parts by mass Toluene: an amount that makes the viscosity of the composition about 500 mPa·s A PET film was prepared as a release sheet. On one surface (release-treated) of this PET film, an applicator was used to apply the adhesive composition so that the thickness after drying was 30 μm. The mixture was dried by heating at 120° C. for 2 minutes to form an adhesive layer overlapping the PET film (release sheet).
<Preparation of dicing tape>
A polyethylene film having a thickness of 80 μm was prepared as a base layer. This polyethylene film and the adhesive layer on the PET film prepared as described above were bonded together at room temperature using a laminator. In this manner, a dicing tape was produced.

<Production of dicing adhesive film with spacers>
The pressure-sensitive adhesive layer of the dicing tape and the adhesive layer with the spacer layer attached thereto were laminated at 70° C. to produce a dicing adhesive film with spacers comprising the spacer layer, adhesive layer, and dicing tape.
Specifically, a laminated sheet was prepared by bonding a spacer layer and an adhesive layer (thickness: 120 μm) at 70° C. This laminated sheet was cut into a circle having a diameter of 330 mm. The cut laminated sheet was then bonded to a dicing tape at room temperature.

The spacer-equipped dicing adhesive films of the examples and comparative examples were manufactured according to the above method. The details of the composition of each film are shown in Table 1.

<Measurement of Elastic Modulus (Tensile Elastic Modulus) of Spacer Layer and Adhesive Layer (Laminated Sheet)>
The spacer layer and adhesive layer (laminate sheet) of each Example and Comparative Example were cut into a strip shape of 40 mm in length and 10 mm in width with a cutter knife. Next, the tensile storage modulus was measured at -30°C to 300°C using a solid viscoelasticity measuring device (RSAIII, manufactured by Rheometric Scientific). The measurement conditions were a frequency of 1 Hz, a heating rate of 10°C/min, and a chuck distance of 20.0 mm. The value of the storage modulus at 25°C was then read and used as the modulus of elasticity.

<Calculation of bending rigidity of spacer layer and adhesive layer (laminate sheet)>
The bending rigidity of the laminated sheets of each of the Examples and Comparative Examples was calculated based on the elastic modulus measured as described above and the above-mentioned formula (1).
In addition, as the values in formula (1), for example, in Example 1, the bending stiffness was calculated using b = 12 [mm], F = 2300 [MPa], h = 0.195 [mm], and λ = 0.0975 [mm]. b = 12 [mm] corresponds to the long side length of the test sample in the performance test described later.

<Measurement of peel force between spacer layer and adhesive layer>
The spacer layer and adhesive layer (laminate sheet) of each Example and Comparative Example were cut into a strip shape with a length of 120 mm and a width of 25 mm using a cutter knife. Double-sided tape was attached to a SUS plate, and the laminate sheet cut into a strip shape was attached to the double-sided tape. At this time, the adhesive layer was attached to the double-sided tape. Next, the peel force between the spacer layer and the adhesive layer was measured using a precision universal testing machine with the product name "Autograph AGS-J" (manufactured by Shimadzu Corporation). The measurement conditions were a peel speed of 300 mm/min, a peel angle of 90 degrees, and a measurement temperature of 25°C. The measured value was then converted to a value per 20 mm width.

<Evaluation of performance in use>
Each spacer-attached dicing adhesive film produced was diced using a DFD6361 manufactured by DISCO. In dicing, pieces were cut to obtain chip-shaped spacer layers and adhesive layers (laminated sheets) measuring 6.0 mm x 12.0 mm. Step cuts were performed using 2030-SE 27HCDD for Z1 and 2030-SE 27HCBB for Z2 as dicing blades. For the blade height, the adhesive layer was half-cut with the Z1 blade, and then the dicing tape was cut 20 μm with the Z2 blade.

(Evaluation of Pickup Performance)
Using a die bonder DB830plus+ manufactured by Fasford Technology, 20 pieces of the fragmented laminated sheet were picked up at room temperature, and the success rate of picking up was calculated.
[Pickup conditions]
Push-up jig: multi-stage pickup, number of stages: 3, jig size: 6mm x 12mm
Push-up amount: 1st stage 300 μm, 2nd stage 600 μm, 3rd stage 900 μm
Push-up speed: 5 mm/sec. Expansion amount: 3 mm

The results of performance evaluation (pickup performance) for the spacer-equipped dicing adhesive films of each Example and Comparative Example are shown in Table 1.

As can be seen from the above evaluation results, the spacer-equipped dicing adhesive film having the spacer layer of the embodiment had better pickup performance than the spacer-equipped dicing adhesive film of the comparative example.

In the embodiment, the bending stiffness of the laminated sheet (spacer layer and adhesive layer) at room temperature (25° C.) is 0.05 N·mm ² or more.
By using the spacer-attached dicing adhesive film of the embodiment having such physical properties in the manufacture of semiconductor integrated circuits, so-called NAND type flash memories and the like can be manufactured efficiently.

The spacer-equipped dicing adhesive film of the present invention is suitable for use, for example, as an auxiliary tool when manufacturing semiconductor integrated circuits.

1: Dicing adhesive film with spacer,
10: spacer layer,
20: adhesive layer,
30: dicing tape,
31: Base material layer, 32: Adhesive layer,
L: bonding wire, Z: substrate,
d', d": die bond layer, w', w": semiconductor chip,
H: peeling tape, T: transfer tape.

Claims (7)

A laminated sheet having an adhesive layer that is adhered to an adherend and a spacer layer that overlaps one surface of the adhesive layer;
a dicing tape that overlaps the other surface of the adhesive layer of the laminated sheet and holds the laminated sheet,
The dicing tape has a base layer and a pressure-sensitive adhesive layer overlapping one surface of the base layer and in contact with the adhesive layer,
A dicing adhesive film with spacers, wherein the bending rigidity of the laminated sheet at room temperature is 0.05 N· ^mm2 or more. The spacer-attached dicing adhesive film according to claim 1, wherein the elastic modulus of the laminated sheet is 1 GPa or more. The spacer-attached dicing adhesive film according to claim 1 or 2, wherein the peel strength between the adhesive layer and the spacer layer is 0.1 N/20 mm or more. The spacer-attached dicing adhesive film according to any one of claims 1 to 3, wherein the thickness of the spacer layer is 3 μm or more and 300 μm or less. The spacer-attached dicing adhesive film according to any one of claims 1 to 4, wherein the thickness of the adhesive layer is 10 μm or more and 200 μm or less. The spacer-attached dicing adhesive film according to any one of claims 1 to 5, wherein the material of the spacer layer is at least one selected from the group consisting of polyimide, polyamideimide, polyester, polybenzimidazole, polyetherimide, polyphenylene sulfide, and polyetheretherketone. A dicing adhesive film with spacer as described in any one of claims 1 to 6, which is used for embedding a semiconductor chip when manufacturing a chip-embedded type semiconductor integrated circuit, or for securing space for stacking a memory semiconductor chip on a control semiconductor chip when manufacturing a wire-embedded type semiconductor integrated circuit.