JPWO2020157805A1 - A method for manufacturing an adhesive composition, a film-like adhesive, an adhesive sheet, and a semiconductor device. - Google Patents

Abstract

Disclosed is an adhesive composition containing a thermosetting resin, a curing agent, and an elastomer, the thermosetting resin containing an epoxy resin having an alicyclic ring, and the elastomer containing an elastomer having a carboxy group. Further, a film-like adhesive using such an adhesive composition is disclosed. Further, a method for manufacturing an adhesive sheet and a semiconductor device using such a film-like adhesive is disclosed.

Description

The present invention relates to an adhesive composition, a film-like adhesive, an adhesive sheet, and a method for manufacturing a semiconductor device.

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. Further, the resin flows in the high temperature pressurization treatment after thermocompression bonding, so that the amount of bleeding increases as compared with the time of thermocompression bonding, which may lead to electrical failure or wire bonding failure.

The present invention has been made in view of such circumstances, and provides an adhesive composition capable of suppressing bleeding during high-temperature pressurization treatment while having good embedding property at the time of thermocompression bonding. The main purpose is that.

One aspect of the present invention is an adhesive composition containing a thermosetting resin, a curing agent, and an elastomer, the thermosetting resin containing an epoxy resin having an alicyclic ring, and the elastomer containing an elastomer having a carboxy group. I will provide a. According to such an adhesive composition, it is possible to suppress bleeding at the time of high temperature pressurization treatment while having good embedding property at the time of thermocompression bonding.

The curing agent may contain a phenolic resin. Further, the elastomer may contain an acrylic resin.

The elastomer may further contain an elastomer having no carboxy group.

The thermosetting resin may further contain an aromatic epoxy resin that does not have an alicyclic ring. The aromatic epoxy resin having no alicyclic ring may be liquid at 25 ° C.

The adhesive composition may further contain an inorganic filler. Further, the adhesive composition may further contain a curing accelerator.

The adhesive composition is used in a semiconductor device in which a first semiconductor element is wire-bonded and connected to a substrate via a first wire, and a second semiconductor element is crimped onto the first semiconductor element. , The second semiconductor element may be used for crimping and embedding at least a part of the first wire.

The present invention further comprises a first wire on a substrate of a composition comprising a thermosetting resin, a curing agent and an elastomer, wherein the thermosetting resin contains an epoxy resin having an alicyclic ring. In a semiconductor device in which the semiconductor elements of the above are bonded and connected by wire bonding and the second semiconductor element is crimped onto the first semiconductor element, the second semiconductor element is crimped and at least a part of the first wire. It may also relate to an application as an adhesive or an application for the production of an adhesive, which is used for embedding.

In another aspect, the present invention provides a film-like adhesive obtained by forming the above-mentioned adhesive composition in the form of a film.

In another aspect, the present invention provides an adhesive sheet comprising a substrate and the film-like adhesive provided on the substrate.

The base material may be a dicing tape. In the present specification, an adhesive sheet whose base material is a dicing tape may be referred to as a “dicing die bonding integrated adhesive sheet”.

The adhesive sheet may further include a protective film laminated on the surface of the film-like adhesive opposite to the substrate.

Further, in another aspect, the present invention comprises a wire bonding step of electrically connecting a first semiconductor element on a substrate via a first wire, and a film-like structure described above on one side of the second semiconductor element. By crimping the second semiconductor element to which the adhesive is attached 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 made into the film-like adhesive. Provided is a method for manufacturing a semiconductor device, comprising a die bonding process for embedding.

In the semiconductor device, the first semiconductor chip is wire-bonded and connected to the semiconductor substrate via the first wire, and the second semiconductor chip is crimped onto the first semiconductor chip via an adhesive film. By doing so, it may be a wire-embedded semiconductor device in which at least a part of the first wire is embedded in the adhesive film, and the first wire and the first semiconductor chip are embedded in the adhesive film. It may be a chip-embedded semiconductor device.

According to the present invention, there is provided an adhesive composition capable of suppressing bleeding during a high temperature pressurization treatment while having good embedding property at the time of thermocompression bonding. Therefore, the film-like adhesive formed by forming the adhesive composition into a film is FOD (Film Over Die), which is a semiconductor chip-embedded film-like adhesive, or FOW (Film), which is a wire-embedded film-like adhesive. It can be useful as OverWire). Further, according to the present invention, there is provided a method for manufacturing an adhesive sheet and a semiconductor device using such a film-like adhesive.

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.

[Adhesive composition]
The adhesive composition according to this embodiment contains (A) a thermosetting resin, (B) a curing agent, and (C) an elastomer. The adhesive composition is thermosetting and can be in a semi-cured (B stage) state and then in a fully cured (C stage) state after the curing treatment.

<Component (A): Thermosetting resin>
The thermosetting resin may contain an epoxy resin from the viewpoint of adhesiveness. The adhesive composition according to the present embodiment contains (A-1) an epoxy resin having an alicyclic ring as a thermosetting resin.

The component (A-1) is a compound having an alicyclic ring and an epoxy group in the molecule. The epoxy group may be bonded to a site other than the alicyclic ring or the alicyclic ring of the compound via a single bond or a linking group (for example, an alkylene group, an oxyalkylene group, etc.). Further, the compound may be a compound having an epoxy group formed together with two carbon atoms constituting the alicyclic ring (that is, an alicyclic epoxy compound). By containing the component (A-1) as the thermosetting resin, it is possible to suppress bleeding during the high temperature pressurization treatment while having good embedding property at the time of thermocompression bonding.

The epoxy equivalent of the component (A-1) is not particularly limited, but may be 90 to 600 g / eq, 100 to 500 g / eq, or 120 to 450 g / eq. When the epoxy equivalent of the component (A-1) is in such a range, better reactivity and fluidity tend to be obtained.

The component (A-1) may be, for example, any of the epoxy resins represented by the following general formulas (1) to (4).

In formula (1), E represents an alicyclic ring, G represents a single bond or an alkylene group, and R ¹ independently represents a hydrogen atom or a monovalent hydrocarbon group. n1 indicates an integer of 1 to 10, and m indicates an integer of 1 to 3.

The number of carbon atoms of E may be 4 to 12, 5 to 11, or 6 to 10. E may be a monocyclic ring or a polycyclic ring, but it is preferably a polycyclic ring, and more preferably a dicyclopentadiene ring. The alkylene group in G may be an alkylene group having 1 to 5 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group and a pentylene group. G is preferably a single bond. Monovalent hydrocarbon group for R ¹ is, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an alkyl group such as a pentyl group, an aryl group such as phenyl group and naphthyl group, a heteroaryl group such as pyridyl group It may be there. R ¹ is preferably a hydrogen atom.

The epoxy resin represented by the general formula (1) may be an epoxy resin represented by the following general formula (1a).

In formula (1a), n1 has the same meaning as above.

Examples of commercially available epoxy resins represented by the general formula (1a) include HP-7200L, HP-7200H, HP-7200 (all manufactured by DIC Corporation), and XD-1000 (manufactured by Nippon Kayaku Co., Ltd.). And so on.

In formula (2), R ² represents a divalent hydrocarbon group.

Divalent hydrocarbon group for R ² is, for example, methylene group, ethylene group, propylene group, butylene group, an alkylene group such as pentylene group, a phenylene group, an arylene group such as a naphthylene group, a hetero arylene group such as pyridylene group It may be there. R ² is preferably an alkylene group having 1 to 5 carbon atoms.

Examples of commercially available epoxy resins represented by the general formula (2) include celoxide 2021P and celoxide 2081 (both manufactured by Daicel Corporation).

In formula (3), R ³ , R ⁴ , and R ⁵ each independently represent a divalent hydrocarbon group.

Examples of the divalent hydrocarbon group in R ³ , R ⁴ , and R ⁵ include the same as those exemplified for the divalent hydrocarbon group in ^{R 2.}

Examples of commercially available products of the epoxy resin represented by the general formula (3) include Syna-Epoxy28 (manufactured by SYNASIA).

In formula (4), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, and n2 represents an integer of 1 to 10.

Examples of the monovalent hydrocarbon group in R ⁶ include those similar to those exemplified for the monovalent hydrocarbon group in ^{R 1.}

Examples of commercially available epoxy resins represented by the general formula (4) include EHPE3150 (manufactured by Daicel Corporation).

From the viewpoint of heat resistance, the component (A-1) is preferably an epoxy resin represented by the general formula (1), and more preferably an epoxy resin represented by the general formula (1a).

The content of the component (A-1) may be 15 to 100% by mass based on the total amount of the component (A). The content of the component (A-1) may be 40% by mass or more, 50% by mass or more, or 60% by mass or more.

The content of the component (A-1) may be 5% by mass or more, 10% by mass or more, or 20% by mass or more based on the total amount of the adhesive composition. When the content of the component (A-1) is 5% by mass or more based on the total amount of the adhesive composition, it has better embedding property at the time of thermocompression bonding and bleeding at the time of high temperature pressurization treatment is good. It tends to be suppressed.

The component (A) may further contain (A-2) an aromatic epoxy resin having no alicyclic ring in addition to the component (A-1). Here, the aromatic epoxy resin having no alicyclic ring is a compound having an aromatic ring and an epoxy group in the molecule and not having an alicyclic ring. Examples of the component (A-2) 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. Novorak type epoxy resin, stillben type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, triphenolphenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, phenylaralkyl type epoxy resin, biphenylaralkyl 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 (A-2) may be a liquid at 25 ° C.

The epoxy equivalent of the component (A-2) is not particularly limited, but may be 90 to 600 g / eq, 100 to 500 g / eq, or 120 to 450 g / eq. When the epoxy equivalent of the component (A-2) is in such a range, better reactivity and fluidity tend to be obtained.

The content of the component (A-2) may be 0 to 85% by mass based on the total amount of the component (A). The content of the component (A-2) may be 60% by mass or less, 50% by mass or less, or 40% by mass or less.

<Component (B): Hardener>
The component (B) is not particularly limited, and those generally used as a curing agent for a thermosetting resin can be used. When the thermosetting resin contains an epoxy resin, the component (B) includes, for example, a phenol resin, an ester compound, an aromatic amine, an aliphatic amine, an acid anhydride and the like. These may be used individually by 1 type or in combination of 2 or more type. Among these, the component (B) may contain a phenol resin from the viewpoint of reactivity and stability over time.

The phenol resin can be used without particular limitation as long as it has a phenolic hydroxyl group in the molecule. Examples of the phenol resin 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, and formaldehyde and the like. Phenols such as novolak type phenol resin, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, phenol and / Alternatively, examples thereof include phenol aralkyl resin synthesized from naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl, naphthol aralkyl resin, biphenyl aralkyl type phenol resin, phenyl aralkyl type phenol resin and the like. These may be used individually by 1 type or in combination of 2 or more type. Among these, from the viewpoint of heat resistance, the phenol resin has a water absorption rate of 2% by mass or less under the condition of a constant temperature and humidity chamber of 85 ° C. and 85% RH for 48 hours, and is a thermogravimetric analyzer (TGA). The rate of decrease in heating mass at 350 ° C. (heating rate: 5 ° C./min, atmosphere: nitrogen) measured in 1) is preferably less than 5% by mass.

Examples of commercially available phenolic resins include Phenolite KA series, TD series (manufactured by DIC Corporation), Millex XLC series, XL series (manufactured by Mitsui Chemicals Co., Ltd.), HE series (manufactured by Air Water Inc.), and the like. Can be mentioned.

The hydroxyl group equivalent of the phenol resin is not particularly limited, but may be 80 to 400 g / eq, 90 to 350 g / eq, or 100 to 300 g / eq. When the hydroxyl group equivalent of the phenol resin is in such a range, better reactivity and fluidity tend to be obtained.

When the component (A) is an epoxy resin and the component (B) is a phenol resin, the ratio of the epoxy equivalent of the epoxy resin to the hydroxyl equivalent of the phenol resin (epoxy equivalent of the epoxy resin / hydroxyl equivalent of the phenol resin) is From the viewpoint of curability, 0.30 / 0.70 to 0.70 / 0.30, 0.35 / 0.65 to 0.65 / 0.35, 0.40 / 0.60 to 0.60 / It may be 0.40, or 0.45 / 0.55-0.55 / 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.

The total content of the component (A) and the component (B) may be 30 to 70% by mass based on the total amount of the adhesive composition. The total content of the component (A) and the component (B) may be 33% by mass or more, 36% by mass or more, or 40% by mass or more, and 65% by mass or less, 60% by mass or less, or 55% by mass. It may be less than or equal to%. When the total content of the component (A) and the component (B) is 30% by mass or more based on the total amount of the adhesive composition, the adhesiveness tends to be improved. When the total content of the component (A) and the component (B) is 70% by mass or less based on the total amount of the adhesive composition, it is possible to prevent the viscosity from becoming too low, and during the high temperature pressurization treatment. Bleed tends to be suppressed more.

<Component (C): Elastomer>
The adhesive composition according to this embodiment contains (C) an elastomer. The adhesive composition according to the present embodiment contains, as an elastomer, an elastomer having a (C-1) carboxy group. The component (C) preferably has a glass transition temperature (Tg) of 50 ° C. or lower of the polymer constituting the elastomer.

The component (C-1) is a compound (elastomer) having a carboxy group in the molecule. By containing the component (C-1) as an elastomer, it is possible to suppress bleeding during high-temperature pressurization treatment while having good embedding property during thermocompression bonding.

Examples of the component (C-1) include acrylic resin, polyester resin, polyamide resin, polyimide resin, silicone resin, butadiene resin, acrylonitrile resin, and modified products thereof.

The component (C-1) may contain an acrylic resin having a carboxy group from the viewpoint of solubility in a solvent and 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, as a structural unit, 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, in addition to a carboxy group. Further, the acrylic resin may be an acrylic rubber such as a copolymer of (meth) acrylic acid ester and acrylonitrile.

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.

The acid value of the component (C-1) may be 1 to 60 mgKOH / g, 2 to 40 mgKOH / g, or 3 to 30 mgKOH / g from the viewpoint of curability. When the acid value is in such a range, bleeding during the high temperature pressurization treatment tends to be further suppressed.

Examples of commercially available products of the component (C-1) component (acrylic resin) include SG-70L, SG-708-6, WS-023 EK30, SG-280 EK23 (all manufactured by Nagase ChemteX Corporation) and the like. Be done.

The component (C) may further contain an elastomer having no (C-2) carboxy group in addition to the component (C-1). The component (C-1) is a compound (elastomer) having no carboxy group in the molecule.

Examples of the component (C-2) include acrylic resin, polyester resin, polyamide resin, polyimide resin, silicone resin, butadiene resin, acrylonitrile resin, and modified products thereof.

The component (C-2) may contain an acrylic resin having no carboxy group from the viewpoint of solubility in a solvent and 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, as a structural unit. Further, the acrylic resin may be an acrylic rubber such as a copolymer of (meth) acrylic acid ester and acrylonitrile.

The glass transition temperature (Tg) of the acrylic resin may be the same as the Tg of the acrylic resin of the component (C-1). The weight average molecular weight (Mw) of the acrylic resin may be the same as that of the acrylic resin Mw of the component (C-1).

Examples of commercially available products of the component (C-2) component (acrylic resin) include SG-P3 and SG-80H (both manufactured by Nagase ChemteX Corporation).

The content of the component (C) may be 20 to 200 parts by mass or 30 to 100 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). When the content of the component (C) is 20 parts by mass or more with respect to 100 parts by mass of the total amount of the components (A) and (B), the handleability (for example, bending property) of the film-like adhesive is better. It tends to be. When the content of the component (C) is 200 parts by mass or less with respect to 100 parts by mass of the total amount of the components (A) and (B), it is possible to further prevent the adhesive composition from becoming too flexible. Tend to be able to. This makes it easier to cut the film-like adhesive during wafer dicing, and tends to further prevent the occurrence of burrs.

Mass ratio of the content of the component (C-1) to the content of the component (C) (the total content of the component (C-1) and the component (C-2)) (content of the component (C-1)) / The content of the component (C)) may be 0.05 to 1, 0.10 to 1, 0.20 to 1, 0.40 to 1, or 0.60 to 1.

<(D) component: inorganic filler>
The adhesive composition according to the present embodiment may further contain (D) an inorganic filler. Examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride, and crystals. Examples thereof include sex silica and amorphous silica. These may be used individually by 1 type and may be used in combination of 2 or more type. From the viewpoint of further improving the thermal conductivity of the obtained film-like adhesive, the inorganic filler may contain aluminum oxide, aluminum nitride, boron nitride, crystalline silica or amorphous silica. Further, from the viewpoint of adjusting the melt viscosity of the adhesive composition and imparting thixotropic properties to the adhesive composition, the inorganic fillers are aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, and the like. It may contain magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, crystalline silica or amorphous silica.

The average particle size of the component (D) may be 0.005 to 0.5 μm or 0.05 to 0.3 μm from the viewpoint of further improving the adhesiveness. Here, the average particle size means a value obtained by converting from the BET specific surface area.

The component (D) may be surface-treated with a surface treatment agent from the viewpoint of compatibility between the surface thereof and a solvent, other components and the like, and adhesive strength. Examples of the surface treatment agent include a silane coupling agent and the like. Examples of the functional group of the silane coupling agent include a vinyl group, a (meth) acryloyl group, an epoxy group, a mercapto group, an amino group, a diamino group, an alkoxy group, an ethoxy group and the like.

The content of the component (D) may be 10 to 90 parts by mass or 10 to 50 parts by mass with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C). When the content of the component (D) is 10 parts by mass or more with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C), the dicing property of the adhesive layer before curing becomes poor. It tends to improve and the adhesive strength of the adhesive layer after curing tends to improve. When the content of the component (D) is 90 parts by mass or less with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C), the decrease in fluidity can be suppressed and the curing can be performed. It is possible to prevent the elastic modulus of the later film-like adhesive from becoming too high.

<Component (E): Curing accelerator>
The adhesive composition according to this embodiment may contain (E) a curing accelerator. The curing accelerator is not particularly limited, and generally used ones 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) is 0.04 to 3 parts by mass or 0.04 to 0.2 parts by mass with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C). May be. When the content of the component (E) is in such a range, both curability and reliability tend to be compatible.

<Other ingredients>
The adhesive composition according to the present embodiment may further contain an antioxidant, a silane coupling agent, a rheology control agent and the like as other components. The content of these components may be 0.02 to 3 parts by mass with respect to 100 parts by mass of the total amount of the component (A), the component (B), and the component (C).

The adhesive composition according to this embodiment may be used as an adhesive varnish diluted with a solvent. The solvent is not particularly limited as long as it can dissolve a component other than the component (D). Examples of the solvent include aromatic hydrocarbons such as toluene, xylene, mesityrene, cumene, and p-simene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; tetrahydrofuran, 1,4-dioxane and the like. Cyclic ethers; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, γ-butyrolactone; Carbonated esters such as ethylene carbonate and propylene carbonate; amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone can be mentioned. These may be used individually by 1 type or in combination of 2 or more type. Of these, the solvent may be toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexane from the viewpoint of solubility and boiling point.

The concentration of the solid component in the adhesive varnish may be 10 to 80% by mass based on the total mass of the adhesive varnish.

The adhesive varnish is prepared by mixing and kneading the component (A), the component (B), the component (C), and the solvent, and if necessary, the component (D), the component (E), and other components. Can be prepared by. Mixing and kneading can be performed by appropriately combining a disperser such as a normal stirrer, a raft machine, a triple roll, a ball mill, and a bead mill. When the component (D) is contained, the mixing time can be shortened by mixing the component (D) and the low molecular weight component in advance and then blending the high molecular weight component. Further, after preparing the adhesive varnish, bubbles in the varnish may be removed by vacuum degassing or the like.

[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 is formed by forming the above-mentioned adhesive composition into a film. The film-like adhesive 10 may be in a semi-cured (B stage) state. Such a film-like adhesive 10 can be formed by applying an adhesive composition to a support film. When an adhesive varnish is used, the film-like adhesive 10 can be formed by applying the adhesive varnish to the support film and heating and drying the solvent to remove it.

The support film is not particularly limited, and examples thereof include films such as polytetrafluoroethylene, polyethylene, polypropylene, polymethylpentene, polyethylene terephthalate, and polyimide. The thickness of the support film may be, for example, 60 to 200 μm or 70 to 170 μm.

As a method of applying the adhesive varnish to the support film, a known method can be used, and examples thereof include a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, and a curtain coating method. Be done. The conditions for heating and drying are not particularly limited as long as the solvent used is sufficiently volatilized, but may be, for example, 50 to 200 ° C. for 0.1 to 90 minutes.

The thickness of the film-like adhesive can be appropriately adjusted according to the intended use. The thickness of the film-like adhesive may be 20 to 200 μm, 30 to 200 μm, or 40 to 150 μm from the viewpoint of sufficiently embedding irregularities of semiconductor chips, wires, wiring circuits of substrates, and the like.

[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 material 20 and the above-mentioned film-like adhesive 10 provided on the base material.

The base material 20 is not particularly limited, but may be a base material film. The base film may be the same as the support film described above.

The base material 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 can be formed by applying an adhesive composition to a base film in the same manner as in the above-mentioned method for forming a film-like adhesive. The method of applying the adhesive composition to the base material 20 may be the same as the method of applying the above-mentioned adhesive composition to the support film.

The adhesive sheet 100 may be formed by using a film-like adhesive prepared in advance. In this case, the adhesive sheet 100 can be formed by laminating 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. Since the adhesive sheet 100 can be continuously manufactured and has high efficiency, it is preferable to form the adhesive sheet 100 using a roll laminator in a heated state.

The thickness of the film-shaped adhesive 10 may be 20 to 200 μm, 30 to 200 μm, or 40 to 150 μm from the viewpoint of embedding property such as unevenness of semiconductor chips, wires, wiring circuits of substrates, and the like. When the thickness of the film-shaped adhesive 10 is 20 μm or more, a more sufficient adhesive force tends to be obtained, and when the thickness of the film-shaped adhesive 10 is 200 μm or less, it is economical and a semiconductor device. It will be possible to meet the demand for miniaturization.

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 the surface of the film-like adhesive 10 opposite to the base material 20. The protective film 30 may be the same as the support film described above. The thickness of the protective film may be, for example, 15 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-based 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 and the first on the substrate 14 are crimped 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 100 μm, size: 8 inches), and the base material 20 is peeled off, so that the film-like adhesive 10 (for example, thickness) is attached to one side of the semiconductor wafer. (110 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 subjected to high-temperature pressure treatment, and 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.

(Examples 1 to 8 and Comparative Examples 1-1 to 1-3, 2 to 4)
<Making an adhesive sheet>
Each component shown below was mixed at the blending ratios (parts by mass) shown in Tables 1, 2 and 3 to prepare a varnish of an adhesive composition having a solid content of 40% by mass using cyclohexanone as a solvent. Next, the obtained varnish was filtered through a 100 mesh filter and vacuum defoamed. The varnish after vacuum defoaming was applied as a base film on a polyethylene terephthalate (PET) film having a thickness of 38 μm and subjected to a mold release treatment. 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 film-like adhesive having a thickness of 110 μm in a semi-cured (B stage) state was obtained on the base film.

The components in Table 1, Table 2, and Table 3 are as follows.

(A) Thermosetting resin (A-1) Epoxy resin having an alicyclic ring A-1-1: Epoxy resin represented by the general formula (1a) (epoxy resin having a dicyclopentadiene structure), DIC stock Made by the company, Product name: HP-7200L, Epoxy equivalent: 250-280g / eq
A-1-2: Epoxy resin represented by the general formula (1a) (epoxy resin having a dicyclopentadiene structure), manufactured by Nippon Kayaku Co., Ltd., trade name: XD-1000, epoxy equivalent: 254 g / eq
A-1-3: Epoxy resin represented by the general formula (2) (liquid at 25 ° C.), manufactured by Daicel Co., Ltd., trade name: seroxide 2021P, epoxy equivalent: 128 to 145 g / eq
A-1-4: Epoxy resin represented by the general formula (4), manufactured by Daicel Corporation, trade name: EHPE3150, epoxy equivalent: 170 to 190 g / eq.
(A-2) Aromatic epoxy resin without alicyclic ring A-2-1: Polyfunctional aromatic epoxy resin, manufactured by Printec Co., Ltd., trade name: VG3101L, epoxy equivalent: 210 g / eq
A-2-2: Cresol novolac type epoxy resin, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name: YDCN-700-10, epoxy equivalent: 209 g / eq
A-2-3: Bisphenol F type epoxy resin (liquid at 25 ° C), manufactured by DIC Corporation, trade name: EXA-830CRP, epoxy equivalent: 159 g / eq
(B) Hardener B-1: Bisphenol A novolak type phenol resin, manufactured by DIC Corporation, trade name: LF-4871, hydroxyl group equivalent: 118 g / eq
B-2: Phenyl aralkyl type phenol resin, manufactured by Mitsui Chemicals, Inc., trade name: XLC-LL, hydroxyl group equivalent: 175 g / eq
B-3: Phenyl aralkyl type phenol resin, manufactured by Air Water Inc., trade name: HE100C-30, hydroxyl group equivalent: 170 g / eq
(C) Elastomer (C-1) Elastomer having a carboxy group C-1-1: Acrylic resin containing a carboxy group (acrylic rubber), manufactured by Nagase ChemteX Corporation, trade name: SG-70L, weight average molecular weight: 900,000. , Acid value: 5 mgKOH / g, Tg: -13 ° C
C-1-2: Carboxy group-containing acrylic resin (acrylic rubber), manufactured by Nagase ChemteX Corporation, trade name: SG-708-6, weight average molecular weight: 700,000, acid value: 9 mgKOH / g, Tg: 4 ° C.
C-1-3: Carboxy group-containing acrylic resin (acrylic rubber), manufactured by Nagase ChemteX Corporation, trade name: WS-023 EK30, weight average molecular weight: 500,000, acid value: 20 mgKOH / g, Tg: -10 ° C.
(C-2) Elastomer without carboxy group C-2-1: Acrylic resin containing carboxy group-free epoxy group (acrylic rubber), manufactured by Nagase ChemteX Corporation, trade name: SG-P3 solvent-modified product, weight average Molecular weight: 800,000, Tg: 12 ° C
C-2-2: Carboxy-free epoxy group-containing acrylic resin (acrylic rubber), manufactured by Nagase ChemteX Corporation, trade name: SG-80H, weight average molecular weight: 350,000, Tg: 11 ° C.
(D) Inorganic filler D-1: Silica filler dispersion, fused silica, manufactured by Admatex Co., Ltd., trade name: SC2050-HLG, average particle size: 0.50 μm
(E) Curing Accelerator E-1: 1-Cyanoethyl-2-phenylimidazole, manufactured by Shikoku Chemicals Corporation, trade name: Curesol 2PZ-CN

<Evaluation of various physical properties>
The obtained adhesive sheet was evaluated for embedding property and bleeding amount.

[Embedability evaluation]
The embedding property of the adhesive sheet was evaluated by preparing the following evaluation samples. The film-like adhesive (thickness 110 μm) obtained above was peeled off from the base film and attached to a dicing tape to obtain a dicing die bonding integrated adhesive sheet. Next, a semiconductor wafer (8 inches) having a thickness of 100 μm was attached to the adhesive side by heating to 70 ° C. Then, this semiconductor wafer was diced to a 7.5 mm square to obtain a semiconductor chip A. Next, a dicing die bonding integrated adhesive sheet (manufactured by Hitachi Kasei Co., Ltd., trade name: HR9004-10) (thickness 10 μm) is prepared and heated to 70 ° C. on a semiconductor wafer (8 inches) having a thickness of 50 μm. I pasted it. Then, by dicing this semiconductor wafer into a 4.5 mm square, a semiconductor chip B with a die bonding film was obtained. Next, an evaluation substrate having a total thickness of 260 μm coated with a solder resist (manufactured by Taiyo Nisshi Co., Ltd., trade name: AUS308) was prepared, and the die bonding film of the semiconductor chip B with the die bonding film and the solder of the evaluation substrate were prepared. The pressure was applied under the conditions of 120 ° C., 0.20 MPa, and 2 seconds so as to be in contact with the resist. Then, the film-like adhesive of the semiconductor chip A and the semiconductor wafer of the semiconductor chip B were pressure-bonded under the conditions of 120 ° C., 0.20 MPa, and 1.5 seconds to obtain an evaluation sample. At this time, the alignment was performed so that the semiconductor chip B crimped earlier was at the center of the semiconductor chip A. The evaluation sample obtained in this way is observed with an ultrasonic digital diagnostic imaging device (manufactured by Insight Co., Ltd., probe: 75 MHz) for the presence or absence of voids, and if voids are observed, per unit area. The ratio of the area of the void was calculated, and these analysis results were evaluated as the implantability. The evaluation criteria are as follows. The results are shown in Table 1, Table 2, and Table 3.
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.

[Bleed amount evaluation]
The amount of bleeding was evaluated for those having "A" or "B" in the above-mentioned implantability evaluation. A sample was prepared in the same manner as the evaluation sample prepared in the above-mentioned embedding property evaluation, and a high-temperature pressure treatment (pressure cure) was performed at 140 ° C., 0.7 MPa, and 30 minutes using a pressure oven. It was used as a sample for bleed evaluation. Using a microscope, the amount of protrusion of the film-like adhesive was measured from the center of the four sides of the evaluation sample, and the maximum value was taken as the bleed amount. The results are shown in Table 1, Table 2, and Table 3.

As shown in Table 1, the adhesive composition of Example 1 containing an epoxy resin having an alicyclic ring and the elastomer containing an elastomer having a carboxy group does not contain them. Comparative Examples 1-1 to 1-3 Compared with the adhesive composition of No. 1, it was possible to suppress bleeding during high temperature pressurization treatment while maintaining good embedding property. Further, also when an epoxy resin having another alicyclic ring is used or an elastomer having another carboxy group is used from Examples 2 and 3 of Table 2 and Examples 4 to 8 of Table 3. It turns out that there is a similar tendency. From these results, it was confirmed that the adhesive composition according to the present invention can suppress bleeding during high temperature pressurization treatment while having good embedding property at the time of thermocompression bonding.

As shown in the above results, the adhesive composition according to the present invention has good embedding property at the time of thermal pressure bonding and can suppress bleeding at the time of high temperature pressurization treatment, so that the adhesive composition is formed in the form of a film. The film-like adhesive can be useful as a chip-embedded film-like adhesive FOD (Film Over Die) or a wire-embedded film-like adhesive FOW (Film Over Wire).

10 ... film-like adhesive, 14 ... substrate, 20 ... base material, 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 (13)

Contains a thermosetting resin, a curing agent, and an elastomer,
The thermosetting resin contains an epoxy resin having an alicyclic ring, and the thermosetting resin contains an epoxy resin.
An adhesive composition comprising an elastomer in which the elastomer has a carboxy group. The adhesive composition according to claim 1, wherein the curing agent contains a phenol resin. The adhesive composition according to claim 1 or 2, wherein the elastomer contains an acrylic resin. The adhesive composition according to any one of claims 1 to 3, further comprising an elastomer in which the elastomer does not have a carboxy group. The adhesive composition according to any one of claims 1 to 4, further comprising an aromatic epoxy resin in which the thermosetting resin does not have an alicyclic ring. The adhesive composition according to claim 5, wherein the aromatic epoxy resin having no alicyclic ring is a liquid at 25 ° C. The adhesive composition according to any one of claims 1 to 6, further comprising an inorganic filler. The adhesive composition according to any one of claims 1 to 7, further comprising a curing accelerator. A film-like adhesive obtained by forming the adhesive composition according to any one of claims 1 to 8 in the form of a film. With the base material
The film-like adhesive according to claim 9, which is provided on the base material, and the film-like adhesive.
Equipped with an adhesive sheet. The adhesive sheet according to claim 10, wherein the base material is a dicing tape. The adhesive sheet according to claim 10 or 11, further comprising a protective film laminated on the surface of the film-like adhesive opposite to the base material. A wire bonding step of electrically connecting a first semiconductor element on a substrate via a first wire,
The laminating step of attaching the film-like adhesive according to claim 9 to one side of the second semiconductor element, and
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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