Film-like adhesive, composition for adhesive, dicing-die attachment film, semiconductor package, and method for manufacturing semiconductor package

Abstract

The present invention pertains to: a film-like adhesive which comprises an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), and in which the polymer component (C) is a ring-opening polymer or an addition polymer obtained through a chain reaction, and has a cyclodextrin structure and an adamantyl group in a side chain; a composition for an adhesive; a dicing-die attachment film; a semiconductor package; and a method for manufacturing the semiconductor package.

Description

Film-like adhesive, adhesive composition, dicing / die attach film, semiconductor package, and method for manufacturing semiconductor package

[0001] The present invention relates to a film-like adhesive, an adhesive composition, a dicing die attach film, a semiconductor package, and a method for producing a semiconductor package.

[0002] In recent years, stacked MCPs (Multi Chip Packages), in which semiconductor chips are stacked in multiple layers, have become widespread and are used as memory packages for mobile phones and portable audio devices. Furthermore, as mobile phones and other devices become more multifunctional, the density and integration of packages are also increasing. Accordingly, the trend toward multi-layer stacking of semiconductor chips is also progressing.

[0003] During the manufacturing process of such memory packages, thermosetting film-like adhesives (die attach films, die bond films) are used to bond the wiring substrate and semiconductor chips, as well as to bond semiconductor chips themselves. As chips are increasingly stacked, thinner die attach films are required. Furthermore, as wafer wiring rules become finer, heat is more likely to be generated on the surface of semiconductor elements. Therefore, to dissipate heat outside the package, thermally conductive fillers are blended into the die attach films, achieving high thermal conductivity.

[0004] As a material for a thermosetting film-like adhesive intended for use as a so-called die attach film, for example, a composition combining a curable resin with a weight average molecular weight of less than 10,000, a curing agent, and eucryptite is known (for example, Patent Document 1).

[0005] Japanese Patent Application Laid-Open No. 2021-24963

[0006] Semiconductor packages are composed of various materials, such as substrates (semiconductors, glass), lead frames (metal), circuits, adhesive layers, and sealing layers. Therefore, differences in the thermal expansion coefficients of each component can lead to warping in semiconductor packages. This trend is becoming stronger as semiconductor packages become smaller and thinner. Furthermore, warping has a greater impact on multi-layer packages with a large number of stacked layers than on single-layer semiconductor packages. Warping in semiconductor packages can cause various problems during assembly and use, such as poor connections between external terminals and the mounting board, cracks in the internal structure, and broken wires. Among the materials used to construct semiconductor packages, resin-containing materials have a relatively high thermal expansion coefficient compared to metal materials, and various studies have been conducted to reduce their thermal expansion. For example, Patent Document 1 points out the problems associated with using inorganic fillers as a means of reducing thermal expansion, and describes how a composition containing a curable resin with a specific weight-average molecular weight, a curing agent, and eucryptite as a filler can reduce the thermal expansion coefficient. However, the composition described in Patent Document 1 has manufacturing limitations due to the use of a special inorganic filler. On the other hand, when a resin-containing material is used as an adhesive or sealant, it is required to exhibit sufficient adhesion to the adherend. Conventionally, it has been known that the inclusion of an inorganic filler reduces adhesive strength, and it has been difficult to achieve both reduced warpage and excellent adhesive strength by using an inorganic filler.

[0007] An object of the present invention is to provide a film-like adhesive that can effectively suppress warping and exhibits excellent adhesive strength with an adherend, and an adhesive composition suitable for preparing this film-like adhesive. Another object of the present invention is to provide a dicing die attach film and semiconductor package, and a method for manufacturing a semiconductor package, using the film-like adhesive.

[0008]

[0006] In view of the above problems, the present inventors have conducted extensive research and have found that the above problems can be solved by incorporating a polymer component having both a cyclodextrin structure and an adamantyl group in the side chain in a film-like adhesive containing an epoxy resin, an epoxy resin curing agent, and a polymer component. The present invention was completed through further research based on the above findings.

[0009] The above-mentioned problems of the present invention are solved by the following means. [1] A film-like adhesive containing an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), wherein the polymer component (C) is an addition polymer or ring-opening polymer produced by a chain reaction, and has a cyclodextrin structure and an adamantyl group in its side chain. [2] The film-like adhesive according to [1], wherein the content of the polymer component (C) is 15 to 90 mass% of the total solid content of the film-like adhesive. [3] The film-like adhesive according to [1] or [2], wherein the proportion of the component having the cyclodextrin structure and the proportion of the component having the adamantyl group in all the components of the polymer component (C) are 20 to 80 mol%. [4] The film-like adhesive according to any one of [1] to [3], wherein the polymer component (C) is an addition polymer produced by chain polymerization of (meth)acryloyl groups or a ring-opening polymer produced by chain polymerization of epoxy groups. [5] The film-like adhesive according to any one of [1] to [4], wherein the epoxy resin (A) comprises a dicyclopentadiene-type epoxy resin. [6] The film-like adhesive according to any one of [1] to [5], wherein the film-like adhesive contains an inorganic filler (D). [7] The film-like adhesive according to any one of [1] to [6], wherein the cured product obtained by curing the film-like adhesive has a storage modulus of 0.1 to 1.0 GPa. [8] The film-like adhesive according to any one of [1] to [7], wherein the cured product obtained by curing the film-like adhesive has a tan δ of 0.2 to 1.2. [9] The film-like adhesive according to any one of [1] to [8], wherein the cured product obtained by curing the film-like adhesive has a linear expansion coefficient α1 of 10 to 50 ppm / °C.

[10] The film adhesive according to any one of [1] to [8], wherein the linear expansion coefficient α1 of the cured product is 10 to 50 ppm / ° C. and the linear expansion coefficient α2 is 80 to 200 ppm / ° C.

[11] The film adhesive according to any one of [1] to

[10] , wherein the thickness of the film adhesive is 1 to 100 μm.

[12] An adhesive composition containing an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), wherein the polymer component (C) is an addition polymer or a ring-opening polymer produced by a chain reaction, and has a cyclodextrin structure and an adamantyl group in a side chain.

[13] A dicing die attach film obtained by laminating the film-like adhesive according to any one of [1] to

[11] and a dicing film.

[14] A method for manufacturing a semiconductor package, comprising: a first step of thermocompression bonding the film-like adhesive according to any one of [1] to

[11] to the backside of a semiconductor wafer having a semiconductor circuit formed on its front surface to provide an adhesive layer, and providing a dicing film via this adhesive layer; a second step of dicing the semiconductor wafer and the adhesive layer together to obtain a semiconductor chip with an adhesive layer, the semiconductor chip comprising a film-like adhesive piece and a semiconductor chip, on the dicing film; a third step of peeling the semiconductor chip with the adhesive layer from the dicing film and thermocompression bonding the semiconductor chip with the adhesive layer to a wiring substrate via the adhesive layer; and a fourth step of thermally curing the adhesive layer.

[15] A wire-bonding type semiconductor package, comprising a thermoset product of the film-like adhesive according to any one of [1] to

[11] .

[0010] In the present invention, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits.

[0011] The film-like adhesive of the present invention can suppress warping and exhibits excellent adhesive strength with an adherend. The adhesive composition of the present invention is suitable for obtaining the film-like adhesive. The semiconductor package manufacturing method of the present invention can obtain a semiconductor package that is less likely to warp and has excellent adhesive reliability.

[0012] FIG. 1 is a schematic vertical cross-sectional view showing a preferred embodiment of the first step of the method for producing a semiconductor package of the present invention. FIG. 2 is a schematic vertical cross-sectional view showing a preferred embodiment of the second step of the method for producing a semiconductor package of the present invention. FIG. 3 is a schematic vertical cross-sectional view showing a preferred embodiment of the third step of the method for producing a semiconductor package of the present invention. FIG. 4 is a schematic vertical cross-sectional view showing a preferred embodiment of the step of connecting bonding wires in the method for producing a semiconductor package of the present invention. FIG. 5 is a schematic vertical cross-sectional view showing an example of a multi-layer stacking embodiment of the method for producing a semiconductor package of the present invention. FIG. 6 is a schematic vertical cross-sectional view showing another example of a multi-layer stacking embodiment of the method for producing a semiconductor package of the present invention. FIG. 7 is a schematic vertical cross-sectional view showing a preferred embodiment of a semiconductor package produced by the method for producing a semiconductor package of the present invention. FIG. 8(A) is an explanatory diagram schematically showing a preferred example of the structure of the polymer component (C), and FIG. 8(B) is an explanatory diagram schematically showing the interaction of the side chains of the polymer component (C). FIG. 9 is an explanatory diagram showing the positional relationship between the inflection point in a measurement curve obtained when a cured product of a film-like adhesive is subjected to thermomechanical analysis (TMA) and the linear expansion coefficients α1 and α2.

[0013] [Film-like adhesive] The film-like adhesive of the present invention contains an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C). The polymer component (C) is a polymer having a cyclodextrin structure and an adamantyl group in each side chain, and the polymerization form of this polymer is addition polymerization or ring-opening polymerization due to a chain reaction. That is, the polymer component (C) is an addition polymer or ring-opening polymer due to a chain reaction, and is a polymer having both a cyclodextrin structure and an adamantyl group in the side chain. Here, in the present invention, "film" refers to a thin film having a thickness of 200 μm or less. The shape, size, etc. are not particularly limited and can be appropriately adjusted depending on the usage mode. The film-like adhesive of the present invention is in a pre-cured state, i.e., a B-stage state. The film-like adhesive of the present invention is resistant to warping when laminated with an adherend, and has excellent adhesive strength to the adherend.

[0014] The film-like adhesive of the present invention can be suitably used as a die attach film in the semiconductor manufacturing process.

[0015] The film adhesive will be described in more detail below.

[0016] <Epoxy Resin (A)> The epoxy resin (A) can be used without any particular limitation as long as it is a thermosetting resin having epoxy groups, and may be liquid, solid, or semi-solid. In the present invention, "liquid" refers to a resin having a softening point below 25°C, "solid" refers to a resin having a softening point of 60°C or higher, and "semi-solid" refers to a resin having a softening point between the softening points of the liquid and solid (25°C or higher and lower than 60°C). The epoxy resin (A) used in the present invention preferably has a softening point of 100°C or lower, from the viewpoint of obtaining a film-like adhesive that can achieve a low melt viscosity in a suitable temperature range (e.g., 60 to 120°C). In the present invention, the softening point is a value measured by a softening point test (ring and ball method) (measurement conditions: in accordance with JIS-K7234:1986).

[0017] The epoxy equivalent of the epoxy resin (A) is preferably 500 g / eq or less, more preferably 150 to 450 g / eq. In the present invention, the epoxy equivalent refers to the number of grams (g / eq) of resin containing 1 gram equivalent of epoxy groups. The weight-average molecular weight of the epoxy resin (A) is usually preferably less than 10,000, more preferably 5,000 or less. There is no particular lower limit, but a value of 300 or more is practical. The weight-average molecular weight is a value determined by GPC (Gel Permeation Chromatography) analysis. (The same applies to other resins hereinafter unless otherwise specified.)

[0018] Examples of the skeleton of the epoxy resin (A) include phenol novolac type, orthocresol novolac type, cresol novolac type, dicyclopentadiene type, biphenyl type, fluorene bisphenol type, triazine type, naphthol type, naphthalenediol type, triphenylmethane type, tetraphenyl type, bisphenol A type, bisphenol F type, bisphenol AD ​​type, bisphenol S type, and trimethylolmethane type.

[0019] The epoxy resin (A) preferably has a fused ring structure in its molecule. The number of rings constituting this fused ring structure is preferably 2 to 7, more preferably 2 to 5, even more preferably 2 to 4, still more preferably 2 or 3, and particularly preferably 2. Furthermore, each ring constituting the fused ring structure may have a bridged structure. The number of ring members in each ring constituting the fused ring structure is preferably a 5-membered ring and / or a 6-membered ring (for example, a dicyclopentadiene structure is a fused ring of a 5-membered ring and a 6-membered ring, and the 6-membered ring has a bridged structure). Examples of fused ring structures that the epoxy resin (A) can have include a dicyclopentadiene structure, a fluorene structure (preferably a fluorene bisphenol structure), and a naphthalene structure (preferably including a naphthol structure or a naphthalene diol structure). Of these, a dicyclopentadiene structure (dicyclopentadiene-type epoxy resin) and a naphthalene structure (naphthalene-type epoxy resin) are preferred. That is, the epoxy resin (A) preferably contains a dicyclopentadiene-type epoxy resin and / or a naphthalene-type epoxy resin, and more preferably contains a dicyclopentadiene-type epoxy resin.

[0020] The content of the epoxy resin (A) is preferably 8 to 80 mass% and more preferably 8 to 70 mass% of the solid content (specifically, components other than the solvent) of the film-like adhesive of the present invention (100 mass%). When the film-like adhesive of the present invention does not contain an inorganic filler (D), the content of the epoxy resin (A) in the solid content is more preferably 23 to 70 mass%, even more preferably 35 to 70 mass%, even more preferably 45 to 70 mass%, and even more preferably 55 to 70 mass%. When the film-like adhesive of the present invention contains an inorganic filler (D), the content of the epoxy resin (A) in the solid content can be 10 to 60 mass%, 20 to 50 mass%, or even 20 to 40 mass%.

[0021] The proportion of the epoxy resin (A) in the total content (100 mass%) of the epoxy resin (A) and the polymer component (C) is preferably 20 to 75 mass%, more preferably 25 to 75 mass%, even more preferably 30 to 70 mass%, and still more preferably 35 to 60 mass%.

[0022] <Epoxy Resin Curing Agent (B)> Any curing agent such as amines, acid anhydrides, or polyhydric phenols can be used as the epoxy resin curing agent (B). In the present invention, a latent curing agent is preferably used from the viewpoint of producing a film-like adhesive that has a low melt viscosity, exhibits curing properties at high temperatures exceeding a certain temperature, has fast curing properties, and has high storage stability that allows for long-term storage at room temperature. Examples of latent curing agents include dicyandiamide compounds, imidazole compounds, curing catalyst composite polyhydric phenol compounds, hydrazide compounds, boron trifluoride-amine complexes, amine imide compounds, polyamine salts, and modified or microencapsulated versions of these. These may be used alone or in combination of two or more. From the viewpoint of superior latency (excellent stability at room temperature and the ability to exhibit curing properties upon heating) and a faster curing rate, it is more preferable to use an imidazole compound.

[0023] The content of the epoxy resin curing agent (B) in the adhesive composition may be appropriately set depending on the type of curing agent and the reaction mode. For example, it can be 0.5 to 100 parts by mass, 1 to 80 parts by mass, 2 to 50 parts by mass, or preferably 4 to 20 parts by mass per 100 parts by mass of the epoxy resin (A). Furthermore, when an imidazole compound is used as the epoxy resin curing agent (B), the content of the imidazole compound is preferably 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, even more preferably 1.5 to 6 parts by mass, or even more preferably 2 to 4 parts by mass per 100 parts by mass of the epoxy resin (A).

[0024] <Polymer component (C)> The polymer component (C) is a polymer, and has a cyclodextrin structure (a monovalent group obtained by removing one hydrogen atom from cyclodextrin) and an adamantyl group (a monovalent group obtained by removing one hydrogen atom from adamantane) in each side chain in one molecule. In other words, the polymer component (C) is a polymer with a chemical structure different from the so-called rotaxane structure. In the polymer compound (C), the cyclodextrin structure acts as a host group and the adamantyl group acts as a guest group, and it is thought that this host-guest interaction contributes to improving adhesive strength. Figure 8 (A) shows a preferred example of the structure of the polymer component (C). The polymer component (C) has a main chain 10 in its molecule, and four cyclodextrin structures 11 and four adamantyl groups 12 in its side chains. Figure 8 (B) shows two molecules of the polymer component (C), in which two cyclodextrin structures 11 possessed by the upper molecule capture two adamantyl groups 12 possessed by the lower molecule (adamantyl groups are captured in the cyclodextrin structures), and one cyclodextrin structure 11 possessed by the lower molecule captures one adamantyl group 12 possessed by the upper molecule.

[0025] The polymer component (C) is an addition polymer or ring-opening polymer formed by a chain reaction, and its main chain is formed by a chain reaction. In the present invention, "addition polymer or ring-opening polymer formed by a chain reaction" means that the polymer component (C) has a structure obtained by a chain reaction, but does not limit its production method. When the polymer component (C) is an addition polymer, the polymer component (C) can be a polymer formed by chain polymerization of groups having a carbon-carbon double bond, such as vinyl groups, vinyl ether groups, vinyl thioether groups, styryl groups, (meth)acryloyl groups, and derivatives thereof. When the polymer component (C) is a ring-opening polymer, the polymer component (C) can be a polymer formed by chain polymerization of cyclic ether groups, such as epoxy groups and oxetanyl groups. The polymer component (C) can preferably be an addition polymer formed by chain polymerization of (meth)acryloyl groups or a ring-opening polymer formed by chain polymerization of epoxy groups. The cyclodextrin structure is preferably a structure derived from α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin. The cyclodextrin structure is preferably an unsubstituted cyclodextrin structure. The adamantyl group is preferably an unsubstituted adamantyl group. The cyclodextrin structure and the adamantyl group may be introduced into the side chain of the polymer component (C) via a linking group.

[0026] The polymer component (C) can be said to be a polymer containing a component (repeating unit) having a cyclodextrin structure and a component having an adamantyl group. The polymer component (C) may contain components other than the component having a cyclodextrin structure and the component having an adamantyl group (hereinafter referred to as "other components"). The component having a cyclodextrin structure and the component having an adamantyl group are usually different components. The proportion of the component having a cyclodextrin structure to all the components of the polymer component (C) (hereinafter also referred to as the cyclodextrin modification rate) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%. The proportion of the component having an adamantyl group to all the components of the polymer component (C) (hereinafter also referred to as the adamantane modification rate) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%. When the polymer component (C) contains other constituent components, the proportion of the other constituent components in the total constituent components of the polymer component (C) is preferably 20 mol % or less, more preferably 10 mol % or less. In the polymer component (C), the molar ratio (B / A) of the content of the constituent component (B) having an adamantyl group to the content of the constituent component (A) having a cyclodextrin structure is preferably 0.25 to 4.00, more preferably 0.40 to 2.50, even more preferably 0.50 to 2.00, still more preferably 0.55 to 1.80, and even more preferably 0.60 to 1.50.

[0027] The weight average molecular weight of the polymer component (C) is not particularly limited, but is preferably 1,000 or more, more preferably 1,000 to 1,000,000, and even more preferably 10,000 to 1,000,000.

[0028] The glass transition temperature (Tg) of the polymer component (C) is not particularly limited, but is preferably 0°C or higher, more preferably 20 to 100°C, and even more preferably 20 to 60°C. The Tg of the polymer component (C) is the peak-top temperature of tan δ in dynamic viscoelasticity measurement. Specifically, Tg can be determined as follows. A solution containing the polymer component (C) is applied to a release film and dried by heating to form a film (polymer film) of the polymer component (C) on the release film. The release film is peeled off and removed from the polymer film, and the polymer film is measured using a dynamic viscoelasticity measuring device (trade name: Rheogel-E4000F, manufactured by UBM) under conditions of a measurement temperature range of 20 to 300°C, a heating rate of 5°C / min, and a frequency of 1 Hz. The obtained tan δ peak-top temperature (the temperature at which tan δ is maximized) is defined as Tg.

[0029] The polymer component (C) may be synthesized or a commercially available product may be used. When synthesized, the synthesis method is not particularly limited, and may be, for example, a method in which a cyclodextrin structure and an adamantyl group are incorporated into a polymer having a reactive group for incorporating a cyclodextrin structure and a reactive group for incorporating an adamantyl group via these reactive groups, or a method in which a monomer having a cyclodextrin structure and a monomer having an adamantyl group are polymerized as raw materials.

[0030] The content of the polymer component (C) is preferably 15 to 90 mass%, and more preferably 25 to 90 mass%, of the total solid content (100 mass%) of the film-like adhesive. When the film-like adhesive of the present invention does not contain an inorganic filler (D), the content of the polymer component (C) in the solid content is more preferably 25 to 75 mass%, even more preferably 25 to 60 mass%, even more preferably 25 to 50 mass%, and even more preferably 25 to 40 mass%. When the film-like adhesive of the present invention contains an inorganic filler (D), the content of the polymer component (C) in the solid content can be 15 to 60 mass%, or 20 to 50 mass%, or even 20 to 40 mass%.

[0031] The proportion of the polymer component (C) in the total content (100 mass%) of the epoxy resin (A) and the polymer component (C) is preferably 25 to 80 mass%, more preferably 25 to 75 mass%, even more preferably 30 to 70 mass%, and still more preferably 40 to 65 mass%.

[0032] <Inorganic filler (D)> The inorganic filler (D) can be any inorganic filler that is normally used in adhesive compositions, without any particular limitations. Examples of the inorganic filler (D) include ceramics such as silica, clay, gypsum, calcium carbonate, barium sulfate, alumina (aluminum oxide), beryllium oxide, magnesium oxide, silicon carbide, silicon nitride, aluminum nitride, and boron nitride, metals or alloys such as aluminum, copper, silver, gold, nickel, chromium, lead, tin, zinc, palladium, and solder, and various inorganic powders such as carbons such as carbon nanotubes, carbon nanofibers, and graphene.

[0033] The particle size (d50) of the inorganic filler (D) is not particularly limited, but from the viewpoint of thinning the film-like adhesive, it is preferably 0.01 to 6.0 μm, more preferably 0.01 to 5.0 μm, more preferably 0.1 to 3.5 μm, and even more preferably 0.1 to 1.0 μm. In the present invention, the particle size (d50) is the so-called median diameter, and means the particle size at 50% cumulative volume when the particle size distribution is measured by a laser diffraction / scattering method and the total volume of particles in the cumulative distribution is taken as 100%.

[0034] The Mohs hardness of the inorganic filler is not particularly limited, but is preferably 2 or more, and more preferably 2 to 9. The Mohs hardness can be measured using a Mohs hardness scale.

[0035] The inorganic filler (D) may be in an embodiment containing a thermally conductive inorganic filler (an inorganic filler with a thermal conductivity of 12 W / m·K or more), or may be in an embodiment containing a thermally non-conductive inorganic filler (an inorganic filler with a thermal conductivity of less than 12 W / m·K). The thermally conductive inorganic filler (D) is a particle made of a thermally conductive material or a particle surface-coated with a thermally conductive material, and the thermal conductivity of these thermally conductive materials is preferably 12 W / m·K or more, more preferably 30 W / m·K or more. When the thermal conductivity of the thermally conductive material is equal to or greater than the above-mentioned preferred lower limit, the amount of inorganic filler (D) to be blended to achieve the desired thermal conductivity can be reduced, the increase in the melt viscosity of the die attach film is suppressed, and the embedding ability into the uneven portions of the substrate when pressure-bonded to the substrate can be further improved. As a result, the generation of voids can be more reliably suppressed. In the present invention, the thermal conductivity of the thermally conductive material means the thermal conductivity at 25°C, and literature values ​​for each material can be used. Even when there is no description in the literature, for example, values ​​measured according to JIS R 1611:2010 for ceramics, or values ​​measured according to JIS H 7801:2005 for metals can be used instead.

[0036] Examples of the thermally conductive inorganic filler (D) include thermally conductive ceramics, such as alumina particles (thermal conductivity: 36 W / m K), aluminum nitride particles (thermal conductivity: 150 to 290 W / m K), boron nitride particles (thermal conductivity: 60 W / m K), zinc oxide particles (thermal conductivity: 54 W / m K), silicon nitride particles (thermal conductivity: 27 W / m K), silicon carbide particles (thermal conductivity: 200 W / m K), and magnesium oxide particles (thermal conductivity: 59 W / m K). Alumina particles are particularly preferred in terms of their high thermal conductivity, dispersibility, and availability. Aluminum nitride particles and boron nitride particles are also preferred because they have even higher thermal conductivities than alumina particles. In the present invention, alumina particles and aluminum nitride particles are particularly preferred. In addition, as the inorganic filler (D) having thermal conductivity, metal particles or particles surface-coated with metals having higher thermal conductivity than ceramics can be mentioned.For example, preferred are single metal fillers such as silver (thermal conductivity: 429 W / m K), nickel (thermal conductivity: 91 W / m K) and gold (thermal conductivity: 329 W / m K), and polymer particles such as acrylic or silicone resin surface-coated with these metals.In the present invention, it is preferred to use silica as the inorganic filler (D).

[0037] The inorganic filler (D) may be surface-treated or surface-modified. Examples of surface treatment agents used for such surface treatment or surface modification include silane coupling agents, phosphoric acid or phosphoric acid compounds, and surfactants. In addition to the matters described in this specification, for example, the descriptions of silane coupling agents, phosphoric acid or phosphoric acid compounds, and surfactants in the section on thermally conductive fillers in WO 2018 / 203527 or the section on aluminum nitride fillers in WO 2017 / 158994 can be applied.

[0038] The method of blending inorganic filler (D) with resin components such as epoxy resin (A), epoxy resin curing agent (B), and polymer component (C) can be a method of directly blending powdery inorganic filler with, if necessary, a silane coupling agent, phosphoric acid or a phosphoric acid compound, or a surfactant (integral blending method), or a method of blending a slurry inorganic filler in which an inorganic filler treated with a surface treatment agent such as a silane coupling agent, phosphoric acid or a phosphoric acid compound, or a surfactant is dispersed in an organic solvent.In addition, the method of treating inorganic filler (D) with a silane coupling agent is not particularly limited, and can include a wet method of mixing inorganic filler (D) and a silane coupling agent in a solvent, a dry method of mixing inorganic filler (D) and a silane coupling agent in a gas phase, and the above-mentioned integral blending method.

[0039] In particular, aluminum nitride particles contribute to high thermal conductivity, but are prone to generating ammonium ions through hydrolysis, so it is preferable to use them in combination with a phenolic resin with low moisture absorption, or to suppress hydrolysis through surface modification.A particularly preferable method for modifying the surface of aluminum nitride is to provide an aluminum oxide layer on the surface to improve water resistance, and then perform surface treatment with phosphoric acid or a phosphoric acid compound to improve affinity with resin.

[0040] The silane coupling agent is a silicon atom to which at least one hydrolyzable group such as an alkoxy group or an aryloxy group is bonded, and in addition, an alkyl group, an alkenyl group, or an aryl group may be bonded. The alkyl group is preferably substituted with an amino group, an alkoxy group, an epoxy group, or a (meth)acryloyloxy group, and more preferably substituted with an amino group (preferably a phenylamino group), an alkoxy group (preferably a glycidyloxy group), or a (meth)acryloyloxy group. Examples of the silane coupling agent include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-methacryloyloxypropyltriethoxysilane.

[0041] The silane coupling agent or surfactant is preferably contained in an amount of 0.1 to 25.0 parts by mass, more preferably 0.1 to 10.0 parts by mass, and even more preferably 0.1 to 2.0 parts by mass, per 100 parts by mass of the inorganic filler (D). By setting the content of the silane coupling agent or surfactant within the above preferred range, it is possible to suppress separation at the adhesive interface due to volatilization of excess silane coupling agent or surfactant during the semiconductor assembly heating process (e.g., the reflow process), while suppressing aggregation of the inorganic filler (D), and it is possible to suppress the occurrence of voids.

[0042] The shape of the inorganic filler (D) may be flake-like, needle-like, filament-like, spherical, or scale-like, but spherical particles are preferred from the viewpoint of high packing density and flowability.

[0043] The content of the inorganic filler (D) in the total solid content (100% by mass) of the film-like adhesive is preferably 50% by mass or less, and more preferably 45% by mass or less. When the film-like adhesive of the present invention contains an inorganic filler (D), the content of the inorganic filler (D) is preferably 10 to 50% by mass, and more preferably 20 to 45% by mass, of the total solid content (100% by mass) of the film-like adhesive.

[0044] When the film-like adhesive of the present invention contains an inorganic filler (D), the content of the inorganic filler (D) is preferably 80 parts by mass or less per 100 parts by mass of the total content of the epoxy resin (A) and the polymer component (C). Within this range, the adhesive strength does not decrease significantly even when the inorganic filler (D) is contained. When the film-like adhesive of the present invention contains an inorganic filler (D), the content of the inorganic filler (D) per 100 parts by mass of the total content of the epoxy resin (A) and the polymer component (C) is preferably 10 to 80 parts by mass, more preferably 20 to 70 parts by mass.

[0045] <Other Components> In addition to the epoxy resin (A), the epoxy resin curing agent (B), the polymer component (C), and the inorganic filler (D), the film-like adhesive of the present invention may further contain an ion trapping agent (ion scavenger), a curing catalyst, a viscosity modifier, an antioxidant, a flame retardant, a colorant, etc., within a range that does not impair the effects of the present invention. For example, other additives described in WO 2017 / 158994 may be included.

[0046] <Thickness of Film-like Adhesive> The thickness of the film-like adhesive is preferably 1 to 100 μm, more preferably 1 to 80 μm, even more preferably 1 to 50 μm, and even more preferably 1 to 20 μm. The thickness of the film-like adhesive can be measured using a contact linear gauge method (a desktop contact-type thickness measuring device).

[0047] <Characteristics of the film-like adhesive> In the present invention, the cured product obtained by curing the film-like adhesive of the present invention (also referred to as the "cured product of the film-like adhesive of the present invention") refers to a product in which the epoxy resin (A) is in a thermoset state (thermoset). In the present invention, the "cured product of the film-like adhesive" refers to a cured product obtained by treating the film-like adhesive at 180°C for 1 hour and curing it.

[0048] The storage modulus of the cured film-like adhesive of the present invention at 25°C is preferably 0.1 to 1.2 GPa, more preferably 0.2 to 1.0 GPa, even more preferably 0.2 to 0.8 GPa, even more preferably 0.2 to 0.6 GPa, and even more preferably 0.2 to 0.4 GPa. A lower storage modulus tends to suppress warping. The storage modulus of the cured film-like adhesive can be measured using a dynamic viscoelasticity measuring device, and specifically, can be measured by the method described in the examples.

[0049] The cured film-like adhesive of the present invention preferably has a loss tangent (tan δ) at 25°C of 0.2 to 1.2, more preferably 0.3 to 1.2, and even more preferably 0.5 to 1.0. When tan δ is within the above preferred range, adhesive strength tends to be increased. The tan δ of the cured film-like adhesive can be measured using a dynamic viscoelasticity measuring device, and specifically, can be measured by the method described in the examples.

[0050] The cured film-like adhesive of the present invention preferably exhibits two different linear expansion coefficients in the temperature range before and after the inflection point in the measurement curve (vertical axis: change (μm), horizontal axis: temperature (°C)) obtained when measuring the linear expansion coefficient by thermomechanical analysis (TMA). The linear expansion coefficient in the temperature range lower than the inflection point is designated α1, and the linear expansion coefficient in the temperature range higher than the inflection point is designated α2. Figure 9 shows an example of the two linear expansion coefficients α1 and α2 in the measurement curve obtained by TMA measurement, along with the inflection point. The cured film-like adhesive of the present invention preferably has a linear expansion coefficient α1 of 10 to 50 ppm / °C, more preferably 10 to 40 ppm / °C, even more preferably 20 to 30 ppm / °C, and even more preferably 30 to 40 ppm / °C. The cured product of the film-like adhesive of the present invention preferably has a linear expansion coefficient α2 of 80 to 200 ppm / °C, more preferably 100 to 140 ppm / °C, and even more preferably 100 to 110 ppm / °C. The cured product of the film-like adhesive of the present invention preferably has a linear expansion coefficient α1 of 10 to 50 ppm / °C and a linear expansion coefficient α2 of 80 to 200 ppm / °C. The linear expansion coefficients α1 and α2 of the film-like adhesive can be measured by the methods described in the examples.

[0051] The film-like adhesive of the present invention can be formed using the adhesive composition described below. For example, the film-like adhesive of the present invention can be formed by preparing the adhesive composition (varnish) of the present invention, applying this composition to a release-treated substrate film, and drying it as necessary. When the film-like adhesive of the present invention is formed using an adhesive composition containing an organic solvent, the solvent is typically removed from the adhesive composition by drying. Therefore, the solvent content in the film-like adhesive of the present invention is 1000 ppm or less (ppm by mass), typically 0.1 to 1000 ppm. Any known release-treated substrate film can be used as long as it functions as a cover film for the resulting film-like adhesive. Examples include release-treated polypropylene (PP), release-treated polyethylene (PE), and release-treated polyethylene terephthalate (PET). Known coating methods can be used as appropriate, such as methods using a roll knife coater, gravure coater, die coater, reverse coater, etc. The drying may be carried out by removing the organic solvent from the adhesive composition to form a film-like adhesive without curing the epoxy resin (A), and may be carried out, for example, by maintaining the composition at a temperature of 80 to 150°C for 1 to 20 minutes.

[0052] The film adhesive of the present invention may be composed solely of the film adhesive of the present invention, or may be in a form in which the above-mentioned release-treated substrate film is bonded to at least one surface of the film adhesive. Furthermore, the film adhesive and a dicing film may be laminated to form a dicing die attach film. Furthermore, the film adhesive of the present invention may be in a form in which the film is cut to an appropriate size, or in a form in which the film is wound into a roll.

[0053] From the viewpoint of inhibiting the curing of the epoxy resin (A), the film-like adhesive of the present invention is preferably stored at a temperature of 10° C. or less before use (before curing).

[0054] [Adhesive Composition] The adhesive composition of the present invention is an adhesive composition suitable for obtaining the above-mentioned film-like adhesive of the present invention. Therefore, the adhesive composition of the present invention contains the above-mentioned epoxy resin (A), epoxy resin curing agent (B), and polymer component (C). The adhesive composition of the present invention may further contain an inorganic filler (D), and may also contain other additives described as other additives for the film-like adhesive of the present invention.

[0055] The adhesive composition of the present invention is specifically specified as follows: An adhesive composition containing an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), wherein the polymer component (C) is an addition polymer or a ring-opening polymer produced by a chain reaction, and has a cyclodextrin structure and an adamantyl group in its side chain.

[0056] The adhesive composition of the present invention usually contains an organic solvent, and the organic solvent is preferably ethyl methyl ketone, for example.

[0057] The total content of the epoxy resin (A), epoxy resin curing agent (B), and polymer component (C) in the adhesive composition of the present invention can be, for example, 50% by mass or more, preferably 60% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, and can also be 90% by mass or more. This percentage may also be 100% by mass or 95% by mass or less. The adhesive composition of the present invention can be suitably used to obtain the film-like adhesive of the present invention. However, the adhesive composition is not limited to the film-like adhesive of the present invention, and can also be suitably used to obtain, for example, a liquid or paste-like adhesive.

[0058] The adhesive composition of the present invention can be obtained by mixing the above components at a temperature at which the epoxy resin (A) does not substantially cure. The order of mixing is not particularly limited. Resin components such as the epoxy resin (A) and the polymer component (C) may be mixed, optionally with a solvent, followed by mixing with the epoxy resin curing agent (B). Here, the polymer component (C) may be mixed separately from the epoxy resin (A). For example, the epoxy resin (A) may be mixed, optionally with a solvent, followed by mixing with the polymer component (C). In either case, mixing in the presence of the epoxy resin curing agent (B) may be carried out at a temperature at which the epoxy resin (A) does not substantially cure, while mixing of the resin components in the absence of the epoxy resin curing agent (B) may be carried out at a higher temperature. Furthermore, when an inorganic filler (D) is used, the order of mixing the inorganic filler (D) is not particularly limited, but it can be mixed at the same time as the epoxy resin curing agent (B).

[0059] From the viewpoint of inhibiting curing of the epoxy resin (A), the adhesive composition of the present invention is preferably stored at a temperature of 10° C. or less before use (before being made into a film-like adhesive).

[0060] [Semiconductor Package and Manufacturing Method Thereof] Next, preferred embodiments of a semiconductor package and a manufacturing method thereof of the present invention will be described in detail with reference to the drawings. Note that in the following description and drawings, the same or corresponding elements are designated by the same reference numerals, and duplicated explanations will be omitted. Figures 1 to 7 are schematic vertical cross-sectional views showing each step of a preferred embodiment of a semiconductor package manufacturing method of the present invention.

[0061] In the semiconductor package manufacturing method of the present invention, as shown in FIG. 1 , in the first step, a film-like adhesive 2 (die attach film 2) of the present invention is thermocompression bonded to the back surface (i.e., the surface of the semiconductor wafer 1 on which no semiconductor circuit is formed) of a semiconductor wafer 1 having at least one semiconductor circuit formed on its surface, to form an adhesive layer (film-like adhesive 2). Next, a dicing film 3 (dicing tape 3) is provided via this adhesive layer (film-like adhesive 2). In FIG. 1 , the film-like adhesive 2 is shown smaller than the dicing film 3, but the sizes (areas) of both films are appropriately set depending on the purpose. Thermocompression bonding is performed at a temperature at which the epoxy resin (A) does not substantially cure. Examples of suitable conditions include a temperature of about 70°C and a pressure of about 0.3 MPa. The semiconductor wafer 1 can be any semiconductor wafer having at least one semiconductor circuit formed on its surface, such as a silicon wafer, a SiC wafer, a GaAs wafer, or a GaN wafer. Known devices such as a roll laminator or manual laminator can be used as appropriate to provide the film adhesive (die attach film) of the present invention on the back surface of the semiconductor wafer 1. In the above, the die attach film and dicing film are attached separately, but when the film adhesive of the present invention is in the form of a dicing die attach film, the film adhesive and dicing film can be attached together.

[0062] 2, the semiconductor wafer 1 and the adhesive layer (die attach film 2) are diced together to obtain, on the dicing film 3, semiconductor chips 4 obtained by dividing the semiconductor wafer and film-like adhesive pieces 2 obtained by dividing the film-like adhesive 2, as a second step. There are no particular limitations on the dicing device, and a conventional dicing device can be used as appropriate.

[0063] Next, in the third step, the semiconductor chip 5 with the adhesive layer is peeled off from the dicing film 3. If necessary, the dicing film may be cured with energy rays to reduce adhesive strength. Peeling can be performed by picking up the semiconductor chip 5 with the adhesive layer. Next, as shown in FIG. 3 , the semiconductor chip 5 with the adhesive layer and the wiring substrate 6 are thermocompression-bonded via the film-like adhesive piece 2, and the semiconductor chip 5 with the adhesive layer is mounted on the wiring substrate 6. The wiring substrate 6 can be any substrate having a semiconductor circuit formed on its surface, such as a printed circuit board (PCB), various lead frames, or a substrate having electronic components such as resistors and capacitors mounted on its surface. The method for mounting the semiconductor chip 5 with the adhesive layer on such a wiring substrate 6 is not particularly limited, and conventional thermocompression-bonding mounting methods can be appropriately employed.

[0064] Next, in the fourth step, the adhesive layer (film-like adhesive piece 2) is thermally cured. There are no particular restrictions on the thermal curing temperature as long as it is equal to or higher than the thermal curing initiation temperature of the film-like adhesive piece 2, and it is adjusted appropriately depending on the type of epoxy resin (A) and epoxy resin curing agent (B) used. For example, 100 to 180°C is preferred, and 140 to 180°C is more preferred from the viewpoint of curing in a shorter time. If the temperature is too high, the components in the film-like adhesive piece 2 tend to volatilize during the curing process, making them more susceptible to foaming. The time for this thermal curing treatment can be set appropriately depending on the heating temperature, and can be, for example, 10 to 120 minutes.

[0065] 4, it is preferable to connect the wiring substrate 6 and the semiconductor chip 5 with the adhesive layer via a bonding wire 7. There are no particular restrictions on the method of connection, and any conventionally known method, such as a wire bonding method or a TAB (Tape Automated Bonding) method, can be used as appropriate.

[0066] Alternatively, multiple semiconductor chips can be stacked by thermocompressing and thermosetting another semiconductor chip 4 on the surface of the mounted semiconductor chip 4 and then connecting it again to the wiring board 6 by wire bonding. For example, there is a method of stacking semiconductor chips by shifting them as shown in Figure 5, or a method of stacking them while embedding bonding wires 7 by making the film-like adhesive pieces 2 thicker for the second and subsequent layers as shown in Figure 6.

[0067] In the semiconductor package manufacturing method of the present invention, as shown in FIG. 7 , it is preferable to seal the wiring substrate 6 and the semiconductor chip 5 with an encapsulating resin 8, thereby obtaining a semiconductor package 9. The encapsulating resin 8 is not particularly limited, and any known encapsulating resin that can be used in the manufacture of semiconductor packages can be used. The method of encapsulation using the encapsulating resin 8 is also not particularly limited, and any commonly used method can be employed. The semiconductor package of the present invention is manufactured by the semiconductor package manufacturing method described above, and at least one location between the semiconductor chip and the wiring substrate or between the semiconductor chips is bonded with a thermoset film-like adhesive of the present invention. The semiconductor package of the present invention is preferably a wire-bonding type semiconductor package that includes a thermoset film-like adhesive of the present invention.

[0068] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples. In the examples and comparative examples, room temperature means 25°C, MEK is methyl ethyl ketone, and PET is polyethylene terephthalate. "%" and "parts" are based on mass unless otherwise specified.

[0069] Example 1 In a 1000 mL separable flask, 50 parts by mass of HP-7200 (trade name, dicyclopentadiene-type epoxy resin, manufactured by DIC Corporation) as an epoxy resin, 50 parts by mass of YNB-W68 (trade name, addition polymer formed by chain polymerization of acryloyl groups, cyclodextrin modification rate 50 mol %, adamantane modification rate 50 mol %, the sum of the proportion (mol %) of components having a cyclodextrin structure and the proportion (mol %) of components having an adamantyl group to all constituents: 100 mol %, Tg 45°C, manufactured by Yushiro Chemical Co., Ltd.) containing a cyclodextrin structure and an adamantyl group in the side chain as a polymer component, and 30 parts by mass of MEK were heated and stirred at a temperature of 110°C for 2 hours to obtain a resin varnish. This resin varnish was transferred to an 800 mL planetary mixer, and 68 parts by mass of silica SO-C2 (trade name, manufactured by Admatechs Co., Ltd.) and 2 parts by mass of 2PHZ-PW (trade name, Imidazole, manufactured by Shikoku Kasei Co., Ltd.) as an epoxy resin curing agent were added, and the mixture was stirred and mixed at room temperature for 1 hour, and then degassed under vacuum to obtain a mixed varnish. The resulting mixed varnish was then applied to a 20 μm thick release film (PET film) and heated and dried at 130° C. for 10 minutes to obtain a film-like adhesive with a release film measuring 300 mm in length, 200 mm in width, and 5 μm in thickness.

[0070] [Example 2] A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in Example 1, the amount of YNB-W68 used when preparing the resin varnish was 30 parts by mass, and the amount of SO-C2 used when preparing the mixed varnish was 55 parts by mass.

[0071] [Example 3] A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in Example 1, the amount of YNB-W68 used when preparing the resin varnish was 70 parts by mass, and the amount of SO-C2 used when preparing the mixed varnish was 80 parts by mass.

[0072] Example 4 A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that SO-C2 was not used when preparing the mixed varnish.

[0073] [Example 5] A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in Example 1, the amount of YNB-W68 used when preparing the resin varnish was 20 parts by mass, and the amount of SO-C2 used when preparing the mixed varnish was 48 parts by mass.

[0074] [Example 6] A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in Example 1, the amount of YNB-W68 used when preparing the resin varnish was 85 parts by mass, and the amount of SO-C2 used when preparing the mixed varnish was 90 parts by mass.

[0075] [Example 7] A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in Example 1, the amount of YNB-W68 used when preparing the resin varnish was 95 parts by mass, and the amount of SO-C2 used when preparing the mixed varnish was 96 parts by mass.

[0076] Example 8 A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in preparing the resin varnish in Example 1, YNB-W116 (trade name, YNB-W68 modified with 80 mol% cyclodextrin and 20 mol% adamantane, Tg 45°C, manufactured by Yushiro Chemical Co., Ltd.) was used as the polymer component instead of YNB-W68.

[0077] Example 9 A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in preparing the resin varnish in Example 1, YNB-W130 (trade name, YNB-W68 modified with 20 mol% cyclodextrin and 80 mol% adamantane, Tg 48°C, manufactured by Yushiro Chemical Co., Ltd.) was used as the polymer component instead of YNB-W68.

[0078] Comparative Example 1 A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that YNB-W68 was not used in the resin varnish and the amount of SO-C2 used when preparing the mixed varnish was 35 parts by mass.

[0079] Comparative Example 2 A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in preparing the resin varnish in Example 1, YNB-W120 (trade name, YNB-W68 modified with 0 mol% cyclodextrin and 100 mol% adamantane, Tg 40°C, manufactured by Yushiro Chemical Co., Ltd.) was used as the polymer component instead of YNB-W68.

[0080] Comparative Example 3 A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that in preparing the resin varnish in Example 1, YNB-W121 (trade name, YNB-W68 modified with 100 mol% cyclodextrin and 0 mol% adamantane, Tg 38°C, manufactured by Yushiro Chemical Co., Ltd.) was used as the polymer component instead of YNB-W68.

[0081] Comparative Example 4 A film-like adhesive with a release film was obtained in the same manner as in Example 1, except that phenoxy resin YP-50 (trade name, Tg 84°C, manufactured by Nippon Steel Chemical & Material Co., Ltd.) was used instead of YNB-W68 when preparing the resin varnish.

[0082] Comparative Example 5 A film-like adhesive with a release film was obtained in the same manner as in Example 4, except that phenoxy resin YP-50 was used instead of YNB-W68 when preparing the resin varnish.

[0083] The compositions of the film adhesives produced in each of the Examples and Comparative Examples are shown in Table 1. A blank cell means that the component was not contained.

[0084] The film adhesives of the Examples and Comparative Examples obtained above were measured for warpage, adhesive strength, storage modulus, tan δ, and coefficient of linear expansion as follows. The results are shown in Table 1.

[0085] [Measurement of Warpage] The obtained film-like adhesive with release film was cut into a length of 100 mm and a width of 100 mm, and attached to a glass plate with a length of 100 mm, a width of 100 mm, and a thickness of 0.05 mm using a manual laminator (trade name: FM-114, manufactured by Technovision Co., Ltd.) at a temperature of 60 ° C. and a pressure of 0.3 MPa. The release film was peeled off from the film-like adhesive to obtain a test specimen. The obtained test specimen was held in a thermostatic chamber at 180 ° C. for 1 hour to thermally cure the film-like adhesive. After thermal curing, the test specimen was removed from the thermostatic chamber and cooled to room temperature, and the warpage of the test specimen was measured. Warpage was measured by placing the test specimen on a platen with the surface to which the film-like adhesive was attached facing up, and measuring the height from the surface of the platen to the warped end of the test specimen using a ruler. When the test specimen was placed as described above, the center of the test specimen was in contact with the surface plate, and all four sides of the test specimen were warped upward toward the surface plate (the side of the test specimen to which the film adhesive was attached). The warpage was measured on the side opposite the side with the greatest warpage among the four sides of the test specimen. The same measurement was performed on three test specimens, and the average value was calculated.

[0086] [Adhesive Strength Measurement] To evaluate the adhesive strength of each film-like adhesive over the entire temperature range to which the cured film-like adhesive is normally exposed during use, the adhesive strength of each film-like adhesive at 25°C and 150°C was measured as follows. The film-like adhesive with release film obtained in each Example and Comparative Example was first adhered to one side of a dummy silicon wafer (8 inch size, 0.35 mm thick) using a manual laminator (trade name: FM-114, manufactured by Technovision Co., Ltd.) at a temperature of 70°C and a pressure of 0.3 MPa. The release film was then peeled from the film-like adhesive, and a dicing tape (trade name: K-13, manufactured by Furukawa Electric Co., Ltd.) and a dicing frame (trade name: DTF2-8-1H001, manufactured by DISCO Corporation) were adhered to the side of the film-like adhesive opposite the dummy silicon wafer (the side where the release film was located) using the same manual laminator at room temperature and a pressure of 0.3 MPa. Next, using a dicing machine (trade name: DFD-6340, manufactured by DISCO Corporation) equipped with a two-axis dicing blade (Z1: NBC-ZH2050 (27HEDD), manufactured by DISCO Corporation / Z2: NBC-ZH127F-SE (BC), manufactured by DISCO Corporation), dicing was carried out from the dummy silicon wafer side to obtain squares of 2 mm x 2 mm in size, and individualized dummy chips (semiconductor chips) with a film-like adhesive (adhesive layer) were obtained on the dicing film. Next, the dummy chip with the film-like adhesive was picked up from the dicing tape using a die bonder (product name: DB-800, manufactured by Hitachi High-Technologies Corporation), and the film-like adhesive side of the dummy chip with the film-like adhesive was bonded to the mounting surface side of a lead frame substrate (42 Alloy series, manufactured by Toppan Printing Co., Ltd.) by thermocompression bonding under conditions of 130°C, a pressure of 0.1 MPa (load 400 gf), and a time of 0.5 seconds, and the film-like adhesive was thermally cured by heating in a dryer at a temperature of 180°C for 1 hour.For the dummy chips with film-like adhesive bonded to the substrate, the shear peel strength (adhesion strength) of the bonded chip to the lead frame substrate was measured using a universal bond tester (product name: Series 4000PXY, manufactured by Nordson Advanced Technologies). The conditions for measuring "25°C adhesion strength" were a stage temperature of 25°C, a head height of 25 μm, and a speed of 0.5 mm / sec. The conditions for measuring "150°C adhesion strength" were a stage temperature of 150°C, a head height of 25 μm, and a speed of 0.5 mm / sec. The results are shown in Table 1. The film-like adhesives of Comparative Examples 1 and 5 peeled under the above-mentioned "150°C adhesion strength" measurement conditions, making it impossible to measure the shear adhesive strength. For this reason, the "150°C adhesion strength" columns for Comparative Examples 1 and 5 in Table 1 are marked with "-."

[0087] [Storage Modulus, tanδ] Each release film-attached film-like adhesive obtained in each Example and Comparative Example was cured at 180°C for 1 hour, cut into a 5 mm x 17 mm piece, and the release film was removed to obtain a test specimen of the cured film-like adhesive. Measurements were performed on the resulting test specimens using a dynamic viscoelasticity measuring device (product name: Rheogel-E4000F, manufactured by UBM Co., Ltd.) at a temperature range of 20 to 300°C, a heating rate of 5°C / min, and a frequency of 1 Hz (tensile mode), to measure the storage modulus and loss modulus at each temperature. The storage modulus at 25°C was determined. Furthermore, the loss tangent tanδ at 25°C was calculated from the storage modulus and loss modulus at 25°C. The measurements were performed in accordance with JIS K7244-4:1999.

[0088] [Measurement of Linear Expansion Coefficient] Each release film-attached film-like adhesive obtained in each Example and Comparative Example was cured at 180°C for 1 hour, cut into a size of 5 mm x 17 mm (200 μm thick), and the release film was peeled off to obtain a test specimen of the cured film-like adhesive. The resulting test specimen was measured using a thermomechanical analyzer (product name: TMA7000, manufactured by Hitachi High-Tech Corporation) under conditions of a measurement temperature range of 20 to 250°C, a heating rate of 5°C / min, and a load of 9.8 g (tensile mode). The point where the slope of the obtained measurement curve changes was defined as the inflection point. The linear expansion coefficient on the lower temperature side of the inflection point was defined as α1, and the linear expansion coefficient on the higher temperature side was defined as α2. The linear expansion coefficients α1 and α2 were calculated using the following formula. Measurement of the linear expansion coefficient was performed in accordance with JIS K7197:2012. α = (1 / L) × (dL / dT) α: Linear expansion coefficient L: Length of test piece dL: Change in length of test piece dT: Change in temperature of test piece

[0089] The results of each of the above tests are shown in the table below.

[0090]

[0091] In the above table, the units of the values ​​listed in the "polymer component," "epoxy resin," "inorganic filler," and "epoxy resin curing agent" columns are all "parts by mass." In the polymer component, "C: 50, A: 50" means that the cyclodextrin modification rate of the polymer component is 50 mol %, and the adamantane modification rate is 50 mol %. "C: 80, A: 20" means that the cyclodextrin modification rate of the polymer component is 80 mol %, and the adamantane modification rate is 20 mol %. "C: 20, A: 80" means that the cyclodextrin modification rate of the polymer component is 20 mol %, and the adamantane modification rate is 80 mol %. "C: 0, A: 100" means that the cyclodextrin modification rate of the polymer component is 0 mol %, and the adamantane modification rate is 100 mol %. "C: 100, A: 0" means that the cyclodextrin modification rate of the polymer component is 100 mol %, and the adamantane modification rate is 0 mol %.

[0092] The film adhesive of Comparative Example 1 did not contain a polymer component. This film adhesive had an inferior adhesive strength of 10 MPa at 25°C. The film adhesives of Comparative Examples 2 to 4 were either polymers lacking either a cyclodextrin structure or an adamantyl group, or phenoxy resins. These film adhesives resulted in warping of 5 mm or more. The film adhesive of Comparative Example 5 exhibited sufficient adhesive strength of 30 MPa at 25°C, but peeled at 150°C, resulting in overall inferior adhesive strength. The film adhesive of Comparative Example 5 had large linear expansion coefficients α1 and α2, and the linear expansion coefficients changed significantly with temperature, which is thought to be why the adhesive strength at 150°C was reduced. In contrast, the film adhesives of Examples 1 to 9, which satisfied the requirements of the present invention, exhibited warping of 0 to 3 mm, adhesive strengths of 15 MPa or more at 25°C, and adhesive strengths of 15 MPa or more at 150°C. It can be seen that by using the film-like adhesive of the present invention, it is possible to form a semiconductor package with reduced warpage without significantly impairing the adhesive strength with the adherend. It can also be seen that a sufficiently high adhesive strength can be achieved regardless of the presence or absence of an inorganic filler (comparison of Example 1 and Example 4). Furthermore, it can be seen that the film-like adhesive of the present invention is resistant to a decrease in adhesive strength even at high temperatures of around 150°C.

[0093] While the present invention has been described in connection with embodiments thereof, we do not intend to limit our invention to any of the details of the description unless otherwise specified, and believe that the claims should be construed broadly without departing from the spirit and scope of the invention as set forth in the appended claims.

[0094] This application claims priority based on Japanese Patent Application No. 2024-053902, filed on March 28, 2024, the contents of which are incorporated herein by reference as part of the present specification.

[0095] REFERENCE SIGNS LIST 1 Semiconductor wafer 2 Adhesive layer (film-like adhesive) 3 Dicing film (dicing tape) 4 Semiconductor chip 5 Semiconductor chip with film-like adhesive piece 6 Wiring substrate 7 Bonding wire 8 Sealing resin 9 Semiconductor package

Claims

1. A film-like adhesive containing an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), wherein the polymer component (C) is an addition polymer or ring-opening polymer produced by a chain reaction, and has a cyclodextrin structure and an adamantyl group in the side chain.

2. The film adhesive according to claim 1, wherein the content of the polymer component (C) is 15 to 90 mass % of the total solid content of the film adhesive.

3. A film-like adhesive according to claim 1 or 2, wherein the proportion of the component having the cyclodextrin structure in the total constituents of the polymer component (C) is 20 to 80 mol %, and the proportion of the component having the adamantyl group is 20 to 80 mol %.

4. A film-like adhesive according to any one of claims 1 to 3, wherein the polymer component (C) is an addition polymer obtained by chain polymerization of (meth)acryloyl groups or a ring-opening polymer obtained by chain polymerization of epoxy groups.

5. A film adhesive according to any one of claims 1 to 4, wherein the epoxy resin (A) comprises a dicyclopentadiene-type epoxy resin.

6. A film-like adhesive according to any one of claims 1 to 5, which contains an inorganic filler (D).

7. A film-like adhesive according to any one of claims 1 to 6, wherein the storage modulus of the cured product obtained by curing the film-like adhesive is 0.1 to 1.0 GPa.

8. The film-like adhesive according to any one of claims 1 to 7, wherein the tan δ of the cured product obtained by curing the film-like adhesive is 0.2 to 1.

2.

9. The film-like adhesive according to any one of claims 1 to 8, wherein the linear expansion coefficient α1 of the cured product obtained by curing the film-like adhesive is 10 to 50 ppm / °C.

10. A film-like adhesive according to any one of claims 1 to 9, wherein the linear expansion coefficient α1 of the cured product obtained by curing the film-like adhesive is 10 to 50 ppm / °C, and the linear expansion coefficient α2 is 80 to 200 ppm / °C.

11. The film adhesive according to any one of claims 1 to 10, wherein the film adhesive has a thickness of 1 to 100 μm.

12. An adhesive composition containing an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), wherein the polymer component (C) is an addition polymer or ring-opening polymer produced by a chain reaction, and has a cyclodextrin structure and an adamantyl group in the side chain.

13. A dicing die attach film comprising the film adhesive according to any one of claims 1 to 11 and a dicing film laminated together.

14. A method for manufacturing a semiconductor package, comprising: a first step of thermocompressing a film-like adhesive according to any one of claims 1 to 11 onto the backside of a semiconductor wafer having a semiconductor circuit formed on its surface to provide an adhesive layer, and providing a dicing film via this adhesive layer; a second step of dicing the semiconductor wafer and the adhesive layer together to obtain a semiconductor chip with an adhesive layer, which comprises a film-like adhesive piece and a semiconductor chip, on the dicing film; a third step of peeling the semiconductor chip with the adhesive layer from the dicing film and thermocompressing the semiconductor chip with the adhesive layer to a wiring substrate via the adhesive layer; and a fourth step of thermally curing the adhesive layer.

15. A wire-bonding type semiconductor package comprising a thermoset film adhesive according to any one of claims 1 to 11.

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