JP7028264B2 - Film-shaped adhesive and its manufacturing method, and semiconductor device and its manufacturing method - Google Patents

Description

The present invention relates to a film-like adhesive and a method for producing the same, and a semiconductor device and the method for producing the same.

Conventionally, silver paste is mainly used for joining a semiconductor chip and a support member for mounting the semiconductor chip. However, with the recent miniaturization and integration of semiconductor chips, the support members used are also required to be miniaturized and miniaturized. On the other hand, when the silver paste is used, there may be problems such as problems during wire bonding due to sticking out of the paste or tilting of the semiconductor chip, difficulty in controlling the film thickness, and generation of voids.

Therefore, in recent years, a film-like adhesive for joining a semiconductor chip and a support member has been used (see, for example, Patent Document 1). When using an adhesive sheet provided with a dicing tape and a film-like adhesive laminated on the dicing tape, the film-like adhesive is attached to the back surface of the semiconductor wafer, and the semiconductor wafer is individualized by dicing to form a film. A semiconductor chip with an adhesive can be obtained. The obtained semiconductor chip with a film-like adhesive can be attached to a support member via the film-like adhesive and bonded by thermocompression bonding.

Japanese Unexamined Patent Publication No. 2007-053240

However, as the size of the semiconductor chip becomes smaller, the force applied per unit area during thermocompression bonding increases, and a phenomenon called bleeding may occur in which the film-like adhesive protrudes from the semiconductor chip.

Further, when the film-like adhesive is used as FOW (Film Over Ware), which is a wire-embedded film-like adhesive, or FOD (Film Over Die), which is a semiconductor chip-embedded film-like adhesive, the viewpoint of improving the embedding property. Therefore, high fluidity is required during thermocompression bonding. Therefore, the frequency and amount of bleeding tend to increase further. In some cases, bleeding may occur even on the upper surface of the semiconductor chip, which may lead to electrical failure or wire bonding failure.

The present invention has been made in view of such circumstances, and the main object of the present invention is to provide a film-like adhesive capable of suppressing bleeding while having good embedding property at the time of thermocompression bonding. do.

As a result of diligent studies by the present inventors, they have found that the above-mentioned problems can be solved by using a film-like adhesive in which an adhesive film is laminated and further adjusting the solvent content and shear viscosity of the film-like adhesive. The present invention has been completed.

One aspect of the present invention is a semiconductor device in which a first semiconductor element is wire-bonded and connected on a substrate via a first wire, and a second semiconductor element is crimped onto the first semiconductor element. A film-like adhesive used for crimping a second semiconductor element and embedding at least a part of a first wire, which is laminated on the first adhesive film and the first adhesive film. A second adhesive film is provided, the solvent content of the film-like adhesive is 1.5% by mass or less based on the total amount of the film-like adhesive, and the shear viscosity of the film-like adhesive at 80 ° C. is 5000 Pa · s. The following film-like adhesives are provided. According to such a film-like adhesive, it is possible to suppress bleeding while having good embedding property at the time of thermocompression bonding.

The thickness of the film-like adhesive may be 3 to 150 μm. The storage elastic modulus of the film-like adhesive at 80 ° C. may be 10 MPa or less.

In another aspect, the present invention is the method for producing a film-like adhesive described above, wherein a varnish of a first adhesive composition containing a solvent is applied onto a substrate, and the first adhesion is applied. The varnish of the agent composition is heated and dried at 50 to 150 ° C. to prepare a first adhesive film having a solvent content of 1.5% by mass or less based on the total amount of the first adhesive film, and contains a solvent. The varnish of the second adhesive composition to be applied is applied onto the substrate, and the varnish of the applied second adhesive composition is heated and dried at 50 to 150 ° C., and the solvent content is the total amount of the second adhesive film. A method for producing a film-like adhesive, comprising a step of producing a second adhesive film having a content of 1.5% by mass or less based on the above, and a step of bonding the first adhesive film and the second adhesive film. I will provide a.

In another aspect, in the present invention, the first semiconductor element is wire-bonded and connected on the substrate via the first wire, and the second semiconductor element is formed into the above-mentioned film on the first semiconductor element. Provided is a semiconductor device in which at least a part of a first wire is embedded in a film-like adhesive by being crimped via an adhesive. Even if the semiconductor device is a wire-embedded semiconductor device in which at least a part of the first wire is embedded in a film-like adhesive, the first wire and the first semiconductor chip are formed in the adhesive film. It may be a chip-embedded semiconductor device that is embedded.

In another aspect, the present invention comprises a wire bonding step of electrically connecting a first semiconductor device on a substrate via a first wire, and a film-like adhesive described above on one side of the second semiconductor device. A die bond that embeds at least a part of the first wire in the film-like adhesive by crimping the second semiconductor element to which the film-like adhesive is attached with the film-like adhesive. Provided are a process and a method for manufacturing a semiconductor device including.

According to the present invention, there is provided a film-like adhesive capable of suppressing bleeding while having good embedding property at the time of thermocompression bonding. Further, according to the present invention, there is provided a method for producing such a film-like adhesive, a semiconductor device using such a film-like adhesive, and a method for producing the same.

It is a schematic sectional drawing which shows the film-like adhesive which concerns on one Embodiment. It is a schematic cross-sectional view which shows the adhesive sheet which concerns on one Embodiment. It is a schematic cross-sectional view which shows the adhesive sheet which concerns on other embodiment. It is a schematic cross-sectional view which shows the semiconductor device which concerns on one Embodiment. It is a schematic sectional drawing which shows a series of steps of the manufacturing method of the semiconductor device which concerns on one Embodiment. It is a schematic sectional drawing which shows a series of steps of the manufacturing method of the semiconductor device which concerns on one Embodiment. It is a schematic sectional drawing which shows a series of steps of the manufacturing method of the semiconductor device which concerns on one Embodiment. It is a schematic sectional drawing which shows a series of steps of the manufacturing method of the semiconductor device which concerns on one Embodiment. It is a schematic sectional drawing which shows a series of steps of the manufacturing method of the semiconductor device which concerns on one Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. However, the present invention is not limited to the following embodiments.

As used herein, (meth) acrylic acid means acrylic acid or methacrylic acid corresponding thereto. The same applies to other similar expressions such as (meth) acryloyl group.

[Film-like adhesive]
FIG. 1 is a schematic cross-sectional view showing a film-like adhesive according to an embodiment. The film-like adhesive 10 includes a first adhesive film 2 and a second adhesive film 4 laminated on the first adhesive film 2. The first adhesive film 2 and the second adhesive film 4 are both thermosetting and can be in a completely cured product (C stage) state after a semi-curing (B stage) state and a completely cured product (C stage) state. The agent composition and the second adhesive composition can be produced by molding into a film. The film-like adhesive 10 can be produced by laminating the obtained first adhesive film 2 and the second adhesive film 4.

The first adhesive film 2 and the second adhesive film 4 constituting the film-shaped adhesive 10 are a thermosetting resin (hereinafter, may be simply referred to as “component (a)”) and a high molecular weight component (hereinafter, may be referred to as “component”). , It may be simply referred to as “component (b)”) and an inorganic filler (hereinafter, may be simply referred to as “component (c)”). The first adhesive film 2 and the second adhesive film 4 are referred to as a coupling agent (hereinafter, may be simply referred to as “(d) component”) and a curing accelerator (hereinafter, simply referred to as “(e) component”). In some cases), it may be further contained. In the first adhesive film 2 and the second adhesive film 4, the solvent used for forming the first adhesive film 2 and the second adhesive film 4 may remain. The solvent content of the film-shaped adhesive 10 (first adhesive film 2 and second adhesive film 4) is 1.5% by mass or less based on the total amount of the film-shaped adhesive. The first adhesive film 2 and the second adhesive film 4 may be the same film or different films, but it is preferable that they are the same film.

<(A) Thermosetting resin>
From the viewpoint of adhesiveness, the component (a) is an epoxy resin (hereinafter, may be simply referred to as “(a1) component”) and a phenol resin that can be a curing agent for the epoxy resin (hereinafter, simply “(a2) component”). In some cases, it is preferable to include).

The component (a1) can be used without particular limitation as long as it has an epoxy group in the molecule. Examples of the component (a1) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolak type epoxy resin, and bisphenol F novolak type. Epoxy resin, dicyclopentadiene skeleton-containing epoxy resin, stillben type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, triphenolphenolmethane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy Examples thereof include resins, naphthalene-type epoxy resins, polyfunctional phenols, and polycyclic aromatic diglycidyl ether compounds such as anthracene. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (a1) may be a cresol novolac type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol A type epoxy resin from the viewpoint of heat resistance.

The epoxy equivalent of the component (a1) may be 90 to 300 g / eq, 110 to 290 g / eq, or 130 to 280 g / eq. When the epoxy equivalent of the component (a1) is in such a range, it tends to be possible to secure the fluidity while maintaining the bulk strength of the film-like adhesive.

The content of the component (a1) is 5 to 50 parts by mass, 10 to 40 parts by mass, or 20 to 30 parts by mass with respect to 100 parts by mass of the total mass of the component (a), the component (b), and the component (c). It may be a mass part. When the content of the component (a1) is 5 parts by mass or more, the embedding property of the film-like adhesive tends to be better. When the content of the component (a1) is 50 parts by mass or less, the occurrence of bleeding tends to be further suppressed.

The component (a2) can be used without particular limitation as long as it has a phenolic hydroxyl group in the molecule. Examples of the component (a2) include phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol and aminophenol and / or naphthols such as α-naphthol, β-naphthol and dihydroxynaphthalene. Novolak-type phenolic resin obtained by condensing or co-condensing with a compound having an aldehyde group such as formaldehyde under an acidic catalyst, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolak, phenols such as phenol. And / or a phenol aralkyl resin synthesized from naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl, a naphthol aralkyl resin, and the like can be mentioned. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (a2) may be a phenol aralkyl resin, a naphthol aralkyl resin, or a novolak type phenol resin from the viewpoint of moisture absorption and heat resistance.

The hydroxyl group equivalent of the component (a2) may be 80 to 250 g / eq, 90 to 200 g / eq, or 100 to 180 g / eq. When the hydroxyl group equivalent of the component (a2) is in such a range, the adhesive strength tends to be maintained higher while maintaining the fluidity of the film-like adhesive.

The softening point of the component (a2) may be 50 to 140 ° C, 55 to 120 ° C, or 60 to 100 ° C.

The content of the component (a2) is 5 to 50 parts by mass, 10 to 40 parts by mass, or 20 to 30 parts by mass with respect to 100 parts by mass of the total mass of the component (a), the component (b), and the component (c). It may be a mass part. When the content of the component (a2) is 5 parts by mass or more, better curability tends to be obtained. When the content of the component (a2) is 50 parts by mass or less, the embedding property of the film-like adhesive tends to be better.

The ratio of the epoxy equivalent of the component (a1) to the hydroxyl equivalent of the component (a2) (the epoxy equivalent of the component (a1) / the hydroxyl equivalent of the component (a2)) is 0.30 / 0.70 from the viewpoint of curability. ~ 0.70 / 0.30, 0.35 / 0.65 ~ 0.65 / 0.35, 0.40 / 0.60 ~ 0.60 / 0.40, or 0.45 / 0.55 ~ It may be 0.55 / 0.45. When the equivalent amount ratio is 0.30 / 0.70 or more, more sufficient curability tends to be obtained. When the equivalent equivalent ratio is 0.70 / 0.30 or less, it is possible to prevent the viscosity from becoming too high, and it is possible to obtain more sufficient fluidity.

<(B) High molecular weight component>
The component (b) preferably has a glass transition temperature (Tg) of 50 ° C. or lower.

Examples of the component (b) include acrylic resin, polyester resin, polyamide resin, polyimide resin, silicone resin, butadiene resin, acrylonitrile resin, and modified products thereof.

The component (b) may contain an acrylic resin from the viewpoint of fluidity. Here, the acrylic resin means a polymer containing a structural unit derived from a (meth) acrylic acid ester. The acrylic resin is preferably a polymer containing a structural unit derived from a (meth) acrylic acid ester having a crosslinkable functional group such as an epoxy group, an alcoholic or phenolic hydroxyl group, or a carboxyl group as a structural unit. Further, the acrylic resin may be acrylic rubber such as a copolymer of (meth) acrylic acid ester and acrylic nitrile.

The glass transition temperature (Tg) of the acrylic resin may be −50 to 50 ° C. or −30 to 30 ° C. When the Tg of the acrylic resin is −50 ° C. or higher, it tends to be possible to prevent the adhesive composition from becoming too flexible. This makes it easier to cut the film-like adhesive during wafer dicing and prevents the occurrence of burrs. When the Tg of the acrylic resin is 50 ° C. or lower, it tends to be possible to suppress a decrease in the flexibility of the adhesive composition. This tends to make it easier to sufficiently embed voids when the film-like adhesive is attached to the wafer. In addition, it is possible to prevent chipping during dicing due to a decrease in the adhesion of the wafer. Here, the glass transition temperature (Tg) means a value measured using a DSC (heat differential scanning calorimeter) (for example, "Thermo Plus 2" manufactured by Rigaku Co., Ltd.).

The weight average molecular weight (Mw) of the acrylic resin may be 100,000 to 3,000,000 or 500,000 to 2,000,000. When the Mw of the acrylic resin is in such a range, the film formability, the strength in the film form, the flexibility, the tackiness, etc. can be appropriately controlled, and the reflowability is excellent and the embedding property is improved. Can be done. Here, Mw means a value measured by gel permeation chromatography (GPC) and converted using a calibration curve made of standard polystyrene.

Examples of commercially available acrylic resins include SG-70L, SG-708-6, WS-023 EK30, SG-280 EK23, HTR-860P-3CSP, and HTR-860P-3CSP-3DB (all of which are Nagase ChemteX stocks). Made by the company).

The content of the component (b) is 5 to 70 parts by mass, 10 to 50 parts by mass, or 15 to 30 with respect to 100 parts by mass of the total mass of the component (a), the component (b), and the component (c). It may be a mass part. When the content of the component (b) is 5 parts by mass or more, the fluidity at the time of molding can be controlled and the handleability at a high temperature can be further improved. When the content of the component (b) is 70 parts by mass or less, the embedding property can be further improved.

<(C) Inorganic filler>
Examples of the component (c) include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisk, and the like. Examples thereof include boron nitride and silica. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (c) may be silica from the viewpoint of compatibility with the resin.

The average particle size of the component (c) may be 0.005 to 1 μm or 0.05 to 0.5 μm from the viewpoint of improving the adhesiveness. Here, the average particle size means a value obtained by converting from the BET specific surface area.

The content of the component (c) is 5 to 50 parts by mass, 15 to 45 parts by mass, or 25 to 40 with respect to 100 parts by mass of the total mass of the component (a), the component (b), and the component (c). It may be a mass part. When the content of the component (c) is 5 parts by mass or more, the fluidity of the film-like adhesive tends to be further improved. When the content of the component (c) is 50 parts by mass or less, the dicing property of the film-like adhesive tends to be better.

<(D) Coupling agent>
The component (d) may be a silane coupling agent. Examples of the silane coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and the like. Be done. These may be used individually by 1 type or in combination of 2 or more type.

The content of the component (d) may be 0.01 to 5 parts by mass with respect to 100 parts by mass of the total mass of the component (a), the component (b), and the component (c).

<(E) Curing accelerator>
The component (e) is not particularly limited, and generally used components can be used. Examples of the component (e) include imidazoles and derivatives thereof, organic phosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts and the like. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (e) may be imidazoles or a derivative thereof from the viewpoint of reactivity.

Examples of the imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole and the like. These may be used individually by 1 type or in combination of 2 or more type.

The content of the component (e) may be 0.01 to 1 part by mass with respect to 100 parts by mass of the total mass of the component (a), the component (b), and the component (c).

<Solvent>
In the first adhesive film 2 and the second adhesive film 4, the solvent used for forming the first adhesive film 2 and the second adhesive film 4 described later may remain. The solvent is not limited as long as it can uniformly dissolve, knead or disperse each component, and conventionally known solvents can be used. Examples of such a solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, toluene, xylene and the like. It is preferable to use methyl ethyl ketone, cyclohexanone, etc. because the drying speed is fast and the price is low.

The solvent content of the film-shaped adhesive 10 (first adhesive film 2 and second adhesive film 4) is 1.5% by mass or less based on the total amount of the film-shaped adhesive. The solvent content may be 1.2% by mass or less, 0.9% by mass or less, or 0.6% by mass or less. When the solvent content is 1.5% by mass or less, bleeding tends to be suppressed. The lower limit of the solvent content is not particularly limited, but may be, for example, 0.01% by mass or more.

By reducing the thickness of the adhesive film, it becomes easier to heat and dry the solvent, and the solvent content tends to be reduced. Therefore, a film having the first adhesive film 2 and the second adhesive film 4, such as the film-like adhesive 10, has higher heat-drying conditions than those having the same thickness composed of a single layer. It becomes easy to reduce the solvent content. Further, the solvent content of the film-shaped adhesive 10 can be adjusted, for example, by changing the conditions for heating and drying the varnish of the adhesive composition.

The first adhesive film 2 and the second adhesive film 4 may further contain other components. Examples of other components include an ion trap agent, a rheology control agent, and the like. The content of the other components may be 0.01 to 20 parts by mass with respect to 100 parts by mass of the total mass of the component (a), the component (b), and the component (c).

The shear viscosity of the film-like adhesive 10 (first adhesive film 2 and second adhesive film 4) at 80 ° C. is 5000 Pa · s or less. The shear viscosity at 80 ° C. may be 3500 Pa · s or less, 2500 Pa · s or less, or 1500 Pa · s or less. When the shear viscosity at 80 ° C. is 5000 Pa · s or less, the fluidity tends to increase and the embedding property tends to improve. The lower limit of the shear viscosity at 80 ° C. is not particularly limited, but may be, for example, 10 Pa · s or more. The shear viscosity at 80 ° C. can be measured, for example, by the method described in Examples.

The shear viscosity of the film-like adhesive 10 at 80 ° C. tends to depend on, for example, the contents of the above-mentioned components (b) and (c), and can be adjusted by changing these.

The storage elastic modulus of the film-like adhesive 10 (first adhesive film 2 and second adhesive film 4) at 80 ° C. may be 10 MPa or less. The storage elastic modulus at 80 ° C. may be 5 MPa or less, 1 MPa or less, or 0.5 MPa or less. When the storage elastic modulus at 80 ° C. is 10 MPa or less, the embedding property tends to be more excellent. The lower limit of the storage elastic modulus at 80 ° C. is not particularly limited, but may be, for example, 0.02 MPa or more.

The storage elastic modulus of the film-like adhesive 10 at 80 ° C. can be adjusted, for example, by changing the functional group equivalent of the component (a).

The thickness of the first adhesive film 2 and the thickness of the second adhesive film 4 may be the same or different from each other, but are preferably the same. The thickness of the first adhesive film 2 and the thickness of the second adhesive film 4 may be 2 to 140 μm, respectively. The thickness of the first adhesive film 2 and the thickness of the second adhesive film 4 may be 5 to 110 μm, 10 to 90 μm, or 20 to 60 μm, respectively. When each of these thicknesses is 2 μm or more, the embedding property tends to be better. When each of these thicknesses is 140 μm or less, the solvent content tends to be lower.

The thickness of the film-like adhesive 10 (the total thickness of the first adhesive film 2 and the second adhesive film 4) is the unevenness of the first wire, the first semiconductor element, the wiring circuit of the substrate, and the like. It may be 3 to 150 μm so that it can be sufficiently filled. The thickness of the film-like adhesive 10 may be 20 to 140 m or 40 to 130 μm. When the thickness of the film-shaped adhesive 10 is 3 μm or more, the embedding property tends to be better. When the thickness of the film-shaped adhesive 10 is 150 μm or less, bleeding tends to be more suppressed.

In the film-like adhesive 10, an adhesive film may be further laminated on the first adhesive film 2 and the second adhesive film 4. That is, the film-like adhesive 10 may include three or more layers of adhesive film. The adhesive film other than the first adhesive film 2 and the second adhesive film 4 may be the same as the first adhesive film 2 and the second adhesive film 4.

[Manufacturing method of film-like adhesive]
In the method for producing a film-like adhesive, a varnish of a first adhesive composition containing a solvent is applied onto a substrate, and the varnish of the applied first adhesive composition is heated and dried at 50 to 150 ° C. The base material is a step of producing a first adhesive film having a solvent content of 1.5% by mass or less based on the total amount of the first adhesive film, and a varnish of a second adhesive composition containing a solvent. The varnish of the second adhesive composition applied above is heated and dried at 50 to 150 ° C., and the solvent content is 1.5% by mass or less based on the total amount of the second adhesive film. The present invention includes a step of producing the adhesive film of No. 1 and a step of laminating the first adhesive film and the second adhesive film.

The varnish of the first adhesive composition and the varnish of the second adhesive composition contain, for example, the components (a) to (e) and, if necessary, the components (d) and (e) in a solvent. It can be prepared by mixing and kneading.

Mixing and kneading can be performed by using a disperser such as a normal stirrer, a raft machine, a three-roll machine, or a ball mill, and combining these as appropriate.

The solvent for producing the varnish of the first adhesive composition and the varnish of the second adhesive composition is not limited as long as it can uniformly dissolve, knead or disperse each of the above components, and is conventionally known. You can use things. Examples of such a solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, toluene, xylene and the like. It is preferable to use methyl ethyl ketone, cyclohexanone, etc. because the drying speed is fast and the price is low.

The base film is not particularly limited, and examples thereof include polyester film, polypropylene film (OPP film and the like), polyethylene terephthalate film, polyimide film, polyetherimide film, polyether naphthalate film, methylpentene film and the like.

As a method for applying the varnish of the first adhesive composition and the varnish of the second adhesive composition to the base film, known methods can be used, for example, a knife coating method, a roll coating method, and a spray. Examples include a coat method, a gravure coat method, a bar coat method, and a curtain coat method. The conditions for heating and drying are not particularly limited as long as the solvent used is sufficiently volatilized, but for example, it can be heated at 50 to 150 ° C. for 1 to 30 minutes. The heat drying may be carried out by gradually raising the temperature in the range of 50 to 150 ° C. By setting the heating temperature to 50 ° C. or higher, the solvent content of the first adhesive film 2 and the second adhesive film 4 (film-like adhesive 10) is set to 1.5% by mass or less based on the total amount of the film-like adhesive. It tends to be easier. On the other hand, by setting the heating temperature to 150 ° C. or lower, it tends to be possible to suppress the progress of curing of the adhesive composition.

In the film-like adhesive 10, the first adhesive film 2 and the second adhesive film 4 are bonded together under predetermined conditions (for example, at room temperature (20 ° C.) or in a heated state) using a roll laminator, a vacuum laminator, or the like. Can be made by.

In the film-like adhesive 10, first, the varnish of the first adhesive composition is applied to the base film, the solvent is heat-dried and removed to prepare the first adhesive film 2, and then the first adhesive film 2 is prepared. It can also be produced by applying the varnish of the second adhesive composition on the adhesive film 2 and removing the solvent by heating and drying to form the second adhesive film.

[Adhesive sheet]
FIG. 2 is a schematic cross-sectional view showing an adhesive sheet according to an embodiment. The adhesive sheet 100 includes a base film 20 and a film-like adhesive 10 composed of a first adhesive film 2 and a second adhesive film 4 provided on the base film 20.

The base film 20 may be a dicing tape. Such an adhesive sheet can be used as a dicing die bonding integrated adhesive sheet. In this case, since the laminating process on the semiconductor wafer is performed once, the work efficiency can be improved.

Examples of the dicing tape include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. Further, the dicing tape may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, and etching treatment, if necessary. The dicing tape is preferably one having adhesiveness. Such a dicing tape may be one in which adhesiveness is imparted to the above-mentioned plastic film, or may be one in which an adhesive layer is provided on one side of the above-mentioned plastic film.

The adhesive sheet 100 first prepares a varnish of the first adhesive composition, applies the varnish to the base film, and heat-drys and removes the solvent to prepare the first adhesive film 2. Next, a second adhesive film 4 can be separately produced from the varnish of the second adhesive composition, and this can be produced by laminating it on the first adhesive film 2.

FIG. 3 is a schematic cross-sectional view showing an adhesive sheet according to another embodiment. The adhesive sheet 110 further includes a protective film 30 laminated on a surface (the surface on the second adhesive film 4 side) opposite to the base film 20 of the film-like adhesive 10. The protective film 30 may be the same as the base film 20 described above. The thickness of the protective film may be, for example, 60 to 200 μm or 70 to 170 μm.

[Semiconductor device]
FIG. 4 is a schematic cross-sectional view showing a semiconductor device according to an embodiment. In the semiconductor device 200, the first semiconductor element Wa of the first stage is wire-bonded to the substrate 14 via the first wire 88, and the second semiconductor element Waa is placed on the first semiconductor element Wa. Is a semiconductor device in which at least a part of the first wire 88 is embedded in the film-like adhesive 10 by being crimped via the film-like adhesive 10. The semiconductor device is a wire-embedded semiconductor device in which at least a part of the first wire 88 is embedded, but is a semiconductor device in which the first wire 88 and the first semiconductor element Wa are embedded. You may. Further, in the semiconductor device 200, the substrate 14 and the second semiconductor element Waa are further electrically connected via the second wire 98, and the second semiconductor element Waa is sealed by the sealing material 42. ing.

The thickness of the first semiconductor element Wa may be 10 to 170 μm, and the thickness of the second semiconductor element Wa may be 20 to 400 μm. The first semiconductor element Wa embedded in the film-shaped adhesive 10 is a controller chip for driving the semiconductor device 200.

The substrate 14 is composed of an organic substrate 90 having two circuit patterns 84 and 94 formed on the surface thereof. The first semiconductor element Wa is crimped onto the circuit pattern 94 via the adhesive 41. The second semiconductor element Waa is via a film-like adhesive 10 so that the circuit pattern 94 in which the first semiconductor element Wa is not crimped, the first semiconductor element Wa, and a part of the circuit pattern 84 are covered. It is crimped to the substrate 14. The film-like adhesive 10 is embedded in the uneven steps caused by the circuit patterns 84 and 94 on the substrate 14. Then, the second semiconductor element Waa, the circuit pattern 84, and the second wire 98 are sealed by the resin-made sealing material 42.

[Manufacturing method of semiconductor devices]
The method for manufacturing a semiconductor device according to the present embodiment includes a first wire bonding step of electrically connecting a first semiconductor element on a substrate via a first wire, and a method of manufacturing the semiconductor device on one side of the second semiconductor element. By crimping the above-mentioned laminating step of attaching the film-like adhesive and the second semiconductor element to which the film-like adhesive is attached via the film-like adhesive, at least a part of the first wire is filmed. It is provided with a die-bonding process of embedding in a state adhesive.

5 to 9 are schematic cross-sectional views showing a series of steps of the method for manufacturing a semiconductor device according to an embodiment. The semiconductor device 200 according to the present embodiment is a semiconductor device in which a first wire 88 and a first semiconductor element Wa are embedded, and is manufactured by the following procedure. First, as shown in FIG. 5, the first semiconductor element Wa having the adhesive 41 is crimped onto the circuit pattern 94 on the substrate 14, and the circuit pattern 84 on the substrate 14 and the first are connected via the first wire 88. The semiconductor element Wa of 1 is electrically bonded and connected (first wire bonding step).

Next, the adhesive sheet 100 is laminated on one side of the semiconductor wafer (for example, thickness: 50 μm, size: 8 inches), and the base film 20 is peeled off, so that the film-like adhesive 10 (for example, for example) is attached to one side of the semiconductor wafer. , Thickness: 135 μm) is pasted. Then, after the dicing tape is attached to the film-shaped adhesive 10, the dicing tape is diced to a predetermined size (for example, 7.5 mm square), so that the second film-shaped adhesive 10 is attached as shown in FIG. (Laminating step).

The temperature condition of the laminating step may be 50 to 100 ° C or 60 to 80 ° C. When the temperature of the laminating step is 50 ° C. or higher, good adhesion to the semiconductor wafer can be obtained. When the temperature of the laminating step is 100 ° C. or lower, the film-like adhesive 10 is suppressed from being excessively flowed during the laminating step, so that it is possible to prevent the film-like adhesive 10 from causing a change in thickness or the like.

Examples of the dicing method include blade dicing using a rotary blade, a method of cutting a film-like adhesive or both a wafer and a film-like adhesive with a laser, and the like.

Then, the second semiconductor element Waa to which the film-shaped adhesive 10 is attached is pressure-bonded to the substrate 14 to which the first semiconductor element Wa is bonded and connected via the first wire 88. Specifically, as shown in FIG. 7, the second semiconductor element Waa to which the film-like adhesive 10 is attached is covered with the film-like adhesive 10 so that the first wire 88 and the first semiconductor element Wa are covered with the film-like adhesive 10. Then, as shown in FIG. 8, the second semiconductor element Waa is crimped to the substrate 14 to fix the second semiconductor element Waa to the substrate 14 (die bond step). In the die bonding step, it is preferable that the film-like adhesive 10 is pressure-bonded at 80 to 180 ° C. and 0.01 to 0.50 MPa for 0.5 to 3.0 seconds. After the die-bonding step, the film-like adhesive 10 is pressurized and heated at 60 to 175 ° C. and 0.3 to 0.7 MPa for 5 minutes or more.

Then, as shown in FIG. 9, after the substrate 14 and the second semiconductor element Waa are electrically connected via the second wire 98 (second wire bonding step), the circuit pattern 84 and the second wire are used. The 98 and the second semiconductor element Wire are sealed with the sealing material 42. The semiconductor device 200 can be manufactured through such a process.

As another embodiment, the semiconductor device may be a wire-embedded semiconductor device in which at least a part of the first wire 88 is embedded.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

<Preparation of varnish for adhesive composition>
(Synthesis Examples 1 to 3)
Cyclohexanone was added to a composition consisting of (a) an epoxy resin and a phenol resin as a thermosetting resin, and (c) an inorganic filler under the product names and composition ratios (unit: parts by mass) shown in Table 1, and the mixture was stirred and mixed. To this, (b) acrylic rubber as a high molecular weight component shown in Table 1 is added and stirred, and further (d) a coupling agent and (e) a curing accelerator shown in Table 1 are added to make each component uniform. The varnish of the adhesive composition of Synthesis Examples 1 to 3 was prepared by stirring up to.

The symbols of each component in Table 1 mean the following.

(Epoxy resin)
YDCN-700-10 (trade name, manufactured by Nippon Steel & Sumitomo Metal Corporation, o-cresol novolac type epoxy resin, epoxy equivalent: 209 g / eq)
EXA-830CRP (trade name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 159 g / eq)
JER YL-980 (trade name, manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent: 185 g / eq)

(Phenol resin)
HE-100C-30 (trade name, manufactured by Air Water Inc., phenol aralkyl resin, hydroxyl group equivalent: 175 g / eq, softening point 77 ° C.)
MEH-7800H (trade name, manufactured by Meiwa Kasei Co., Ltd., phenol aralkyl resin, hydroxyl group equivalent 178 g / eq, softening point 87 ° C)

(High molecular weight component)
HTR-860P-3CSP (trade name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight average molecular weight: 800,000, Tg: 12 ° C)
SG-70L (trade name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight average molecular weight: 900,000, Tg: -13 ° C)

(Inorganic filler)
SC2050-HLG (trade name, manufactured by Admatex Co., Ltd., silica filler dispersion, average particle size: 0.50 μm)
SE2050-MC (trade name, manufactured by Admatex Co., Ltd., silica filler dispersion, average particle size 0.50 μm)

(Coupling agent)
A-1160 (trade name, manufactured by Momentive Performance Materials Japan GK, γ-ureidopropyltriethoxysilane)
A-189 (trade name, manufactured by Momentive Performance Materials Japan GK, γ-mercaptopropyltrimethoxysilane)

(Curing accelerator)
2PZ-CN (trade name, manufactured by Shikoku Chemicals Corporation, 1-cyanoethyl-2-phenylimidazole)
TPP-K (trade name, manufactured by Hokuko Chemical Industry Co., Ltd., tetraphenylphosphonium tetraphenylborate)

<Making an adhesive sheet>
(Example 1)
The varnish of the adhesive composition of Synthesis Example 1 was filtered through a 100 mesh filter and vacuum defoamed. As a base film, a polyethylene terephthalate (PET) film having been subjected to a mold release treatment having a thickness of 38 μm was prepared, and a varnish of an adhesive composition after vacuum defoaming was applied onto the PET film. The applied varnish was heated and dried in two steps at 90 ° C. for 5 minutes and then at 140 ° C. for 5 minutes. In this way, an adhesive sheet having a 60 μm-thick adhesive film in the B stage state was obtained on the PET film. Next, two adhesive sheets are prepared, arranged so that the adhesive films are in contact with each other, laminated on a hot plate at 70 ° C., and a film-like adhesive having a thickness of 120 μm consisting of two layers of adhesive films is applied. An adhesive sheet to be provided was prepared.

(Example 2)
In the same manner as in Example 1, the varnish of the adhesive composition of Synthesis Example 1 was changed to the varnish of the adhesive composition of Synthesis Example 2, and the thickness of the two-layer adhesive film was 120 μm. An adhesive sheet containing the agent was prepared.

(Example 3)
In the same manner as in Example 1, the varnish of the adhesive composition of Synthesis Example 1 was changed to the varnish of the adhesive composition of Synthesis Example 3, and the thickness of the two-layer adhesive film was 120 μm. An adhesive sheet containing the agent was prepared.

(Comparative Example 1)
The varnish of the adhesive composition of Synthesis Example 1 was filtered through a 100 mesh filter and vacuum defoamed. As a base film, a polyethylene terephthalate (PET) film having been subjected to a mold release treatment having a thickness of 38 μm was prepared, and a varnish of an adhesive composition after vacuum defoaming was applied onto the PET film. The applied varnish was heated and dried in two steps at 90 ° C. for 10 minutes and then at 150 ° C. for 10 minutes. In this way, an adhesive sheet having a single-layer film-like adhesive having a thickness of 120 μm in the B stage state was produced on the PET film.

(Comparative Example 2)
The same as in Comparative Example 1 except that the two-step heat-drying at 90 ° C. for 10 minutes and 150 ° C. for 10 minutes was changed to the two-step heat-drying at 120 ° C. for 20 minutes and 160 ° C. for 20 minutes. An adhesive sheet having a single-layer 120 μm-thick film-like adhesive in a B-stage state was produced on the PET film.

(Comparative Example 3)
The thickness of the single layer in the B stage state on the PET film in the same manner as in Comparative Example 2 except that the varnish of the adhesive composition of Synthesis Example 1 was changed to the varnish of the adhesive composition of Synthesis Example 2. An adhesive sheet provided with a 120 μm film-like adhesive was prepared.

(Comparative Example 4)
The thickness of the single layer in the B stage state on the PET film in the same manner as in Comparative Example 2 except that the varnish of the adhesive composition of Synthesis Example 1 was changed to the varnish of the adhesive composition of Synthesis Example 3. An adhesive sheet provided with a 120 μm film-like adhesive was prepared.

<Evaluation of various physical properties>
Regarding the film-like adhesives of the adhesive sheets of Examples 1 to 3 and Comparative Examples 1 to 4, the solvent content, the shear modulus at 80 ° C., the storage elastic modulus at 80 ° C., the embedding property after curing at 175 ° C. under pressure oven, and The amount of bleeding was measured.

(Solvent content)
The base film is peeled off from the adhesive sheet, 1 g of the film-like adhesive is added to 30 g of a 1,4-dioxane solution containing 1% by mass of 2- (2-ethoxyethoxy) ethanol, and the mixture is shaken with a shaker. Stir for hours. The stirred solution was measured by gas chromatography (carrier gas: helium, column temperature: 140 ° C.), and the solvent content of the film-like adhesive was determined from the peak area of each solvent and 2- (2-ethoxyethoxy) ethanol. Mass%) was estimated. The results are shown in Table 2.

(Viscosity at 80 ° C)
The base film was peeled off from the adhesive sheet and punched into a 10 mm square in the thickness direction to obtain a 10 mm square quadrangular laminate. A circular aluminum plate jig having a diameter of 8 mm was set in the dynamic viscoelastic device ARES (manufactured by Rheometric Scientific Co., Ltd.), and a square laminate of the film-like adhesive punched out was set therein. Then, the temperature was raised to 80 ° C. at a heating rate of 5 ° C./min while applying a strain of 5% at 35 ° C., and the shear viscosity (Pa · s) at 80 ° C. was measured. The results are shown in Table 2.

(Storage modulus at 80 ° C)
The base film was peeled off from the adhesive sheet and cut into a length of 4 cm and a width of 4 mm. Set in a dynamic viscoelastic device (product name: Rheogel-E4000, manufactured by UBM Co., Ltd.), apply a tensile load to raise the temperature to 80 ° C at a frequency of 10 Hz and a temperature rise rate of 3 ° C / min, and then raise the temperature to 80 ° C. The storage elastic modulus in. The results are shown in Table 2.

(Embedability after curing in a 175 ° C pressure oven)
The film-like adhesive of the adhesive sheet was attached to a semiconductor wafer (8 inches) having a thickness of 50 μm at 70 ° C. Next, they were diced to a 7.5 mm square to obtain a semiconductor device. Further, the film-like adhesive HR-9004T-10 (manufactured by Hitachi Kasei Co., Ltd., thickness 20 μm) was attached to a semiconductor wafer (8 inches) having a thickness of 50 μm at 70 ° C. Next, they were diced to a 3.0 mm square to obtain chips. The individualized chip with HR-9004T-10 is pressure-bonded to an evaluation substrate having a maximum surface unevenness of 6 μm at 130 ° C., 0.20 MPa for 2 seconds, heated at 120 ° C. for 2 hours, and semi-cured. I let you. Next, a 7.5 mm semiconductor device with a film-like adhesive was pressure-bonded to the sample thus obtained under the conditions of 120 ° C., 0.20 MPa, and 2 seconds. At this time, the alignment was performed so that the chip with the HR-9004T-10 that had been crimped earlier was in the center. The obtained sample was put into a pressure oven, heated from 35 ° C. to 175 ° C. at a heating rate of 3 ° C./min, and heated at 175 ° C. for 30 minutes. The sample obtained in this way was observed for the presence or absence of voids with an ultrasonic imaging device SAT (Hitachi Construction Machinery Co., Ltd., product number FS200II, probe: 25 MHz), and if voids were observed, the area of voids per unit area. Was calculated, and these analysis results were evaluated as implantability. The evaluation criteria are as follows. The results are shown in Table 2.
A: No voids were observed.
B: Voids were observed, but the proportion was less than 5 area%.
C: Voids were observed, and the ratio was 5 area% or more.

(Measurement of bleed amount)
In the evaluation of the embedding property after curing in the 175 ° C. pressure oven, the bleeding amount was measured for those having "A" and "B". The sample was prepared by the same procedure as the sample prepared by the implantability after curing in the pressure oven at 175 ° C. The amount of protrusion of the film-like adhesive was measured from the center of each of the four sides of the obtained sample, and the average value was taken as the bleeding amount. The results are shown in Table 2.

From Table 1, it was found that the adhesive sheet composed of the two layers of the adhesive films of Examples 1 to 3 had good embedding property and suppressed bleeding. On the other hand, the adhesive sheet using the single-layer adhesive film having a solvent content of more than 1.5% by mass in Comparative Example 1 had good embedding property, but could not suppress bleeding. In addition, the adhesive sheet using a single-layer adhesive film having a shear viscosity of more than 5000 Pa · s at 80 ° C. did not have sufficient embedding property. From these results, it was confirmed that the film-like adhesive of the present invention can suppress bleeding while having good embedding property at the time of thermocompression bonding.

2 ... 1st adhesive film, 4 ... 2nd adhesive film, 10 ... film-like adhesive, 14 ... substrate, 20 ... base film, 30 ... protective film, 41 ... adhesive, 42 ... encapsulant, 84 , 94 ... circuit pattern, 88 ... first wire, 90 ... organic substrate, 98 ... second wire, 100, 110 ... adhesive sheet, 200 ... semiconductor device, Wa ... first semiconductor element, Waa ... second Semiconductor element.

Claims (6)

In a semiconductor device in which a first semiconductor element is wire-bonded and connected on a substrate via a first wire, and a second semiconductor element is crimped onto the first semiconductor element, the second A film-like adhesive used for crimping a semiconductor element and embedding at least a part of the first wire.
A first adhesive film and a second adhesive film laminated on the first adhesive film are provided.
The solvent content of the film-like adhesive is 1.5% by mass or less based on the total amount of the film-like adhesive.
A film-like adhesive having a shear viscosity of the film-like adhesive at 80 ° C. of 5000 Pa · s or less. The film-like adhesive according to claim 1, wherein the film-like adhesive has a thickness of 3 to 150 μm. The film-like adhesive according to claim 1 or 2, wherein the film-like adhesive has a storage elastic modulus of 10 MPa or less at 80 ° C. The method for producing a film-like adhesive according to any one of claims 1 to 3.
The varnish of the first adhesive composition containing a solvent is applied onto the substrate, and the applied varnish of the first adhesive composition is heated and dried at 50 to 150 ° C., and the solvent content is first. The step of producing the first adhesive film having an amount of 1.5% by mass or less based on the total amount of the adhesive film of
The varnish of the second adhesive composition containing a solvent is applied onto the substrate, and the applied varnish of the second adhesive composition is heated and dried at 50 to 150 ° C., and the solvent content is second. A step of producing a second adhesive film having an amount of 1.5% by mass or less based on the total amount of the adhesive film of
The step of bonding the first adhesive film and the second adhesive film,
A method for producing a film-like adhesive. The second semiconductor element is described in any one of claims 1 to 3 on the first semiconductor element while the first semiconductor element is wire-bonded and connected on the substrate via the first wire. A semiconductor device in which at least a part of the first wire is embedded in the film-like adhesive by being crimped via the film-like adhesive. A wire bonding step of electrically connecting a first semiconductor element on a substrate via a first wire,
A laminating step of attaching the film-like adhesive according to any one of claims 1 to 3 to one side of the second semiconductor element.
A die-bonding step of embedding at least a part of the first wire in the film-like adhesive by crimping the second semiconductor element to which the film-like adhesive is attached via the film-like adhesive.
A method for manufacturing a semiconductor device.

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