Die bonding film and method for manufacturing same, dicing / die bonding integrated film and method for manufacturing same, and semiconductor device and method for manufacturing same

Abstract

Disclosed is a die bonding film. This die bonding film contains silver-containing particles produced through a reduction method, and a compound represented by formula (1). The silver-containing particle content is 70 mass% or more based on the total amount of the die bonding film. [In formula (1), R1, R2, R3, and R4 each independently represent a hydrogen atom, a halogen atom, a methyl group that may be substituted with a halogen atom, or an ethyl group that may be substituted with a halogen atom.　However, at least one of R1, R2, R3, and R4 is a halogen atom, a methyl group that may be substituted with a halogen atom, or an ethyl group that may be substituted with a halogen atom.]

Description

Die bonding film and manufacturing method thereof, dicing / die bonding integrated film and manufacturing method thereof, and semiconductor device and manufacturing method thereof

[0001] The present disclosure relates to a die bonding film and a manufacturing method thereof, a dicing / die bonding integrated film and a manufacturing method thereof, and a semiconductor device and a manufacturing method thereof.

[0002] Conventionally, semiconductor devices are manufactured through the following steps. First, a semiconductor wafer is attached to a dicing adhesive sheet, and then the semiconductor wafer is divided into semiconductor chips (dicing step). This is followed by an ultraviolet irradiation step, a pick-up step, a pressure-bonding step, a die-bonding step, and other steps. Patent Document 1 discloses an adhesive sheet (a dicing / die-bonding integrated film) that has both the function of fixing the semiconductor wafer in the dicing step and the function of bonding the semiconductor chip to a substrate in the die-bonding step. In the dicing step, the semiconductor wafer and the adhesive layer are divided into individual chips, thereby obtaining chips with adhesive layer pieces.

[0003] In recent years, devices known as power semiconductor devices that control electric power and the like have become widespread. Power semiconductor devices are prone to generating heat due to the current supplied thereto, and therefore require excellent heat dissipation properties. Patent Document 2 discloses a conductive die bonding film and a dicing tape with a die bonding film (a dicing / die bonding integrated film) that have higher heat dissipation properties after curing than before curing.

[0004] JP 2008-218571 A Japanese Patent No. 6396189 A

[0005] However, semiconductor devices manufactured using conventional die bonding films and dicing / die bonding integrated films do not have sufficient heat dissipation properties, and there is still room for improvement.

[0006] Therefore, an object of the present disclosure is to provide a die bonding film and a dicing / die bonding integrated film that enable the manufacture of semiconductor devices with excellent heat dissipation properties.

[0007] The inventors conducted intensive research to solve the above problems and discovered that the thermal conductivity of a die bonding film can be improved by incorporating silver-containing particles that have been surface-treated with a surface treatment agent and a specified compound into the die bonding film, thereby completing the invention of the present disclosure.

[0008] The present disclosure provides a method for producing a die bonding film according to [1] to [7], a method for producing a dicing-die bonding integrated film according to [8], a method for producing a semiconductor device according to [9], a die bonding film according to

[10] to

[12] , a dicing-die bonding integrated film according to

[13] , and a semiconductor device according to

[14] . [1] A method for producing a die bonding film, comprising: a first step of preparing a raw material varnish containing silver-containing particles produced by a reduction method, a compound represented by formula (1), and an organic solvent; a second step of mixing the raw material varnish to obtain an adhesive varnish; and a third step of applying the adhesive varnish to a support film and removing the organic solvent to obtain a die bonding film, wherein the content of the silver-containing particles is 70 mass% or more based on the total solid content of the adhesive varnish. [In formula (1), R １ , R ２ , R ３ , and R ４ each independently represents a hydrogen atom, a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom. １ , R ２ , R ３ , and R ４at least one of which is a halogen atom, a methyl group optionally substituted with a halogen atom, or an ethyl group optionally substituted with a halogen atom.] [2] A method for producing a die bonding film, comprising: a first step of preparing a raw material varnish containing silver-containing particles surface-treated with a surface treatment agent, a compound represented by formula (1), and an organic solvent; a second step of mixing the raw material varnish to obtain an adhesive varnish; and a third step of applying the adhesive varnish to a support film and removing the organic solvent to obtain a die bonding film, wherein the content of the silver-containing particles is 70 mass% or more based on the total solid content of the adhesive varnish. [In formula (1), R １ , R ２ , R ３ , and R ４ each independently represents a hydrogen atom, a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom. １ , R ２ , R ３ , and R ４at least one of which is a halogen atom, a methyl group optionally substituted with a halogen atom, or an ethyl group optionally substituted with a halogen atom.] [3] The method for producing a die bonding film according to [1] or [2], wherein the second step is a step of mixing the raw varnish under a temperature condition of 50°C or higher. [4] The method for producing a die bonding film according to any of [1] to [3], wherein the raw varnish further contains a thermosetting resin, a curing agent, and an elastomer. [5] The method for producing a die bonding film according to [4], wherein the thermosetting resin comprises an epoxy resin that is liquid at 25°C. [6] The method for producing a die bonding film according to any of [1] to [3], wherein the second step is a step of adding a thermosetting resin, a curing agent, and an elastomer to the mixed raw varnish to obtain an adhesive varnish that further contains these. [7] The method for producing a die bonding film according to [6], wherein the thermosetting resin comprises an epoxy resin that is liquid at 25°C. [8] A method for manufacturing a dicing and die bonding integrated film, comprising the steps of: preparing a dicing tape having a base layer and a pressure-sensitive adhesive layer provided on the base layer; and bonding a die bonding film manufactured by the method for manufacturing a die bonding film described in any one of [1] to [7] to the pressure-sensitive adhesive layer of the dicing tape, to form an adhesive layer made of the die bonding film on the pressure-sensitive adhesive layer. [9] A method for manufacturing a semiconductor device, comprising the steps of: attaching the adhesive layer of the dicing and die bonding integrated film manufactured by the method for manufacturing a dicing and die bonding integrated film described in [8] to a semiconductor wafer; singulating the semiconductor wafer and the adhesive layer; picking up a semiconductor chip with adhesive layer pieces from the dicing tape; and adhering the semiconductor chip with adhesive layer pieces to a support member via the adhesive layer pieces.

[10] A die bonding film comprising silver-containing particles produced by a reduction method and a compound represented by formula (1), wherein the content of the silver-containing particles is 70 mass% or more based on the total amount of the die bonding film. [In formula (1), R１ , R ２ , R ３ , and R ４ each independently represents a hydrogen atom, a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom. １ , R ２ , R ３ , and R ４ at least one of which is a halogen atom, a methyl group optionally substituted with a halogen atom, or an ethyl group optionally substituted with a halogen atom.]

[11] The die bonding film according to

[10] , further comprising a thermosetting resin, a curing agent, and an elastomer.

[12] The die bonding film according to

[11] , wherein the thermosetting resin comprises an epoxy resin that is liquid at 25°C.

[13] An integrated dicing and die bonding film comprising: a dicing tape having a base layer and a pressure-sensitive adhesive layer provided on the base layer; and an adhesive layer disposed on the pressure-sensitive adhesive layer of the dicing tape, the adhesive layer comprising the die bonding film according to any one of

[10] to

[12] .

[14] A semiconductor device comprising: a semiconductor chip; a support member on which the semiconductor chip is mounted; and an adhesive member provided between the semiconductor chip and the support member and adhering the semiconductor chip to the support member, wherein the adhesive member comprises a cured product of the die bonding film according to any one of

[10] to

[12] .

[0009] According to the present disclosure, a die bonding film and a dicing / die bonding integrated film that enable the manufacture of a semiconductor device with excellent heat dissipation properties are provided. Also, according to the present disclosure, a method for manufacturing these films is provided. Furthermore, according to the present disclosure, a semiconductor device using such a die bonding film and a method for manufacturing a semiconductor device using a dicing / die bonding integrated film are provided.

[0010] Fig. 1 is a schematic cross-sectional view showing one embodiment of a die bonding film. Fig. 2 is a schematic cross-sectional view showing one embodiment of a dicing / die bonding integrated film. Fig. 3 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a semiconductor device. Figs. 3(a), (b), (c), (d), (e), and (f) are cross-sectional views showing each step. Fig. 4 is a schematic cross-sectional view showing one embodiment of a semiconductor device.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as appropriate. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including steps, etc.) are not essential unless specifically stated. The sizes of the components in each figure are conceptual, and the relative size relationships between the components are not limited to those shown in each figure.

[0012] The same applies to the numerical values ​​and ranges in this specification, and do not limit the present disclosure. In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0013] In this specification, "(meth)acrylate" means at least one of an acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl". Furthermore, "(poly)" means both the presence and absence of the prefix "poly". Furthermore, "A or B" may contain either A or B, or may contain both. Furthermore, unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified.

[0014] [Die Bonding Film] Fig. 1 is a schematic cross-sectional view showing one embodiment of a die bonding film. The die bonding film 10A shown in Fig. 1 may be provided on a support film 20, as shown in Fig. 1. The die bonding film 10A is thermosetting, and can go through a semi-cured (B-stage) state and then become a cured (C-stage) state after a curing treatment.

[0015] The die bonding film 10A contains silver-containing particles (component (a)) produced by a reduction method or silver-containing particles surface-treated (coated) with a surface treatment agent, and a compound (component (b)) represented by formula (1). The die bonding film 10A may further contain a thermosetting resin (component (c)), a curing agent (component (d)), and an elastomer (component (e)) as necessary.

[0016] Component (a): Silver-containing particles produced by a reduction method or silver-containing particles surface-treated (coated) with a surface treatment agent. Component (a) is a component used to increase the thermal conductivity of die bonding films and improve the heat dissipation properties of semiconductor devices. The silver-containing particles may be, for example, particles composed of silver (particles composed of silver alone, silver particles) or silver-coated metal particles in which the surfaces of metal particles (copper particles, etc.) are coated with silver. Examples of silver-coated metal particles include silver-coated copper particles. Component (a) may be particles composed of silver (silver particles).

[0017] Component (a) may be silver particles produced by a reduction method (silver particles produced by a liquid-phase (wet) reduction method using a reducing agent). In a liquid-phase (wet) reduction method using a reducing agent, a surface treatment agent (lubricant) is usually added from the viewpoint of particle size control and prevention of aggregation and fusion, and the silver particles produced by a liquid-phase (wet) reduction method using a reducing agent have their surfaces treated (coated) with the surface treatment agent (lubricant). In other words, silver particles (silver-containing particles) produced by a reduction method are usually surface-treated with a surface treatment agent (lubricant). Examples of the surface treatment agent include fatty acid compounds such as oleic acid (melting point: 13.4°C), myristic acid (melting point: 54.4°C), palmitic acid (melting point: 62.9°C), and stearic acid (melting point: 69.9°C); fatty acid amide compounds such as oleic acid amide (melting point: 76°C) and stearic acid amide (melting point: 100°C); fatty alcohol compounds such as pentanol (melting point: -78°C), hexanol (melting point: -51.6°C), oleyl alcohol (melting point: 16°C), and stearyl alcohol (melting point: 59.4°C); and fatty nitrile compounds such as oleanitrile (melting point: -1°C). The surface treatment agent may have a low melting point (e.g., a melting point of 100°C or less) and high solubility in organic solvents, such as a fatty acid compound. That is, component (a) may be silver particles (silver-containing particles) surface-treated (coated) with a fatty acid compound.

[0018] The shape of component (a) is not particularly limited and may be, for example, flake-like, plate-like, needle-like, spherical, etc. When component (a) is spherical, a die bonding film with improved surface roughness (Ra) tends to be obtained.

[0019] The average particle size of component (a) may be 0.01 to 10 μm. When the average particle size of component (a) is 0.01 μm or more, an increase in viscosity when the adhesive varnish is prepared can be prevented, the desired amount of component (a) can be contained in the die bonding film, and the wettability of the die bonding film to the adherend can be ensured, tending to exhibit better adhesion. When the average particle size of component (a) is 10 μm or less, the film formability is superior, and the addition of component (a) tends to improve the thermal conductivity, resulting in improved heat dissipation of the semiconductor device. Furthermore, by setting the particle size within this range, the thickness of the die bonding film can be made thinner, further enabling the semiconductor chip to be highly stacked, and the occurrence of chip cracks due to protrusion of conductive particles from the die bonding film tends to be prevented. The average particle size of component (a) may be 0.1 μm or more, 0.5 μm or more, or 1.0 μm or more, or may be 8.0 μm or less, 5.0 μm or less, or 3.0 μm or less.

[0020] In this specification, the average particle size of component (a) is the particle size when the ratio (volume fraction) of component (a) to the total volume of component (a) is 50% (laser 50% particle size (D ５０ )) The average particle size (D ５０ ) can be determined by measuring a suspension of component (a) in water by a laser scattering method using a laser scattering particle size measuring device (e.g., Microtrac).

[0021] The content of the (a) component is 70% by mass or more, based on the total amount of the die bonding film (or the total solids content of the adhesive varnish described below). When the content of the (a) component is 70% by mass or more, based on the total amount of the die bonding film, the thermal conductivity of the die bonding film can be improved, and as a result, the heat dissipation properties can be improved. The content of the (a) component may be 72% by mass or more, 74% by mass or more, or 75% by mass or more, based on the total amount of the die bonding film. The upper limit of the content of the (a) component is not particularly limited, but may be 90% by mass or less, 85% by mass or less, or 80% by mass or less, based on the total amount of the die bonding film. When the content of the (a) component is 90% by mass or less, based on the total amount of the die bonding film, other components can be more sufficiently contained in the die bonding film. This ensures the wettability of the die bonding film to the adherend, allowing better adhesion to be exhibited.

[0022] The content of component (a) may be 24.0 vol% or more, 24.5 vol% or more, or 25.0 vol% or more, based on the total amount (total volume) of the die bonding film. When the content of component (a) is 24.0 vol% or more, based on the total amount (total volume) of the die bonding film, the thermal conductivity of the die bonding film can be improved, and as a result, the heat dissipation performance of the semiconductor device can be improved. The content of component (a) may be 33.0 vol% or less, 30.0 vol% or less, or 28.0 vol% or less, based on the total amount (total volume) of the die bonding film. When the content of component (a) is 33.0 vol% or less, based on the total amount (total volume) of the die bonding film, other components can be more sufficiently contained in the die bonding film. This ensures the wettability of the die bonding film to the adherend, allowing for better adhesion.

[0023] The content (vol %) of the component (a) can be determined by, for example, multiplying the density of the die bonding film by x (g / cm ３ ), (a) the density of the component is y (g / cm ３), where z (mass %) is the mass proportion of the component (a) in the die bonding film. The mass proportion of the component (a) in the die bonding film can be determined by performing thermogravimetric analysis using, for example, a thermogravimetric differential thermal analyzer (TG-DTA). The density of the die bonding film and the component (a) can be determined by measuring the mass and specific gravity using a hydrometer. Content (volume %) of the component (a) = (x / y) x z (I) TG-DTA measurement conditions: temperature range 30 to 600°C (heating rate 30°C / min), maintained at 600°C for 20 minutes Air flow rate: 300 mL / min Thermogravimetric differential thermal analyzer: TG / DTA220, manufactured by Seiko Instruments Inc. Hydrometer: EW-300SG, manufactured by Alpha Mirage Co., Ltd.

[0024] Component (b): A compound represented by formula (1) The die bonding film 10A contains component (b). When the die bonding film contains components (a) and (b), the thermal conductivity of the die bonding film can be improved, and as a result, the heat dissipation performance of the semiconductor device can be improved.

[0025]

[0026] In formula (1), R １ , R ２ , R ３ , and R ４ each independently represents a hydrogen atom, a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom.

[0027] Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0028] The methyl group optionally substituted with a halogen atom refers to an unsubstituted methyl group or a methyl group in which at least one hydrogen atom of the methyl group is substituted with a halogen atom. Examples of the methyl group substituted with a halogen atom include a fluoromethyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, a difluoromethyl group, and a trifluoromethyl group.

[0029] The ethyl group optionally substituted with a halogen atom refers to an unsubstituted ethyl group or an ethyl group in which at least one hydrogen atom has been substituted with a halogen atom. Examples of the ethyl group substituted with a halogen atom include a fluoroethyl group, a chloroethyl group, a bromoethyl group, an iodoethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, and a perfluoroethyl group.

[0030] R １ , R ２ , R ３ , and R ４ At least one of R is a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom. １ , R ２ , R ３ , and R ４ At least one of R may be a methyl group. １ , R ２ , R ３ , and R ４ Among these, the number of halogen atoms, methyl groups which may be substituted with halogen atoms, and ethyl groups which may be substituted with halogen atoms may be one. １ , R ２ , R ３ , and R ４ may be a halogen atom, a methyl group optionally substituted with a halogen atom, or an ethyl group optionally substituted with a halogen atom, and R １ , R ２ , R ３ , and R ４ The remaining three may be hydrogen atoms.

[0031] Examples of compounds represented by formula (1) that satisfy these conditions include 2-methylglutaric acid, 2-ethylglutaric acid, 2-fluoroglutaric acid, 2-chloroglutaric acid, 2-bromoglutaric acid, 2-iodoglutaric acid, 2-(trifluoromethyl)glutaric acid, 2-(difluoromethyl)glutaric acid, 2-(chloromethyl)glutaric acid, 2-(fluoromethyl)glutaric acid, 2-(dichloromethyl)glutaric acid, 2-(trichloromethyl)glutaric acid, 2-(2-fluoroethyl)glutaric acid, 2-(2,2,2-trifluoroethyl)glutaric acid, 2-(2-chloroethyl)glutaric acid, 2-(2,2-difluoroethyl)glutaric acid, etc. Among these, the compound represented by formula (1) may contain 2-methylglutaric acid.

[0032] The content of component (b) may be 0.1 to 5 parts by mass when the total amount of component (a) is 100 parts by mass. When the content of component (b) is 0.1 part by mass or more when the total amount of component (a) is 100 parts by mass, the thermal conductivity of the die bonding film tends to be further improved. When the content of component (b) is 5 parts by mass or less when the total amount of component (a) is 100 parts by mass, the amounts of other components (particularly components (c), (d), and (e)) can be sufficiently secured, and the film formability tends to be excellent.

[0033] The content of component (b) may be 0.2 mass% or more or 0.3 mass% or more, and may be 3 mass% or less or 2 mass% or less, based on the total amount of the die bonding film (or the total solids amount of the adhesive varnish described below).

[0034] Component (c): Thermosetting Resin Component (c) is a component that has the property of forming three-dimensional bonds between molecules and curing when heated, etc., and is a component that exhibits adhesive properties after curing. Component (c) may be an epoxy resin. Component (c) may contain an epoxy resin that is liquid at 25°C. Any epoxy resin can be used without particular limitations as long as it has an epoxy group in the molecule. Epoxy resins may have two or more epoxy groups in the molecule.

[0035] Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, bisphenol F novolac type epoxy resins, stilbene type epoxy resins, triazine skeleton-containing epoxy resins, fluorene skeleton-containing epoxy resins, triphenolmethane type epoxy resins, biphenyl type epoxy resins, xylylene type epoxy resins, biphenyl aralkyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, polyfunctional phenols, diglycidyl ether compounds of polycyclic aromatics such as anthracene, etc. Among these, the epoxy resin may be a bisphenol type epoxy resin or a cresol novolac type epoxy resin from the viewpoint of the heat resistance of the cured product, etc.

[0036] The epoxy resin may contain an epoxy resin that is liquid at 25°C (hereinafter, may be simply referred to as "liquid epoxy resin"). By containing such a liquid epoxy resin, a die bonding film with improved surface roughness (Ra) tends to be obtained. Examples of commercially available liquid epoxy resins include EXA-830CRP (trade name, manufactured by DIC Corporation) and YDF-8170C (trade name, Nippon Steel Chemical & Material Co., Ltd.).

[0037] The epoxy equivalent of the epoxy resin is not particularly limited, but may be 90 to 300 g / eq or 110 to 290 g / eq. When the epoxy equivalent of the epoxy resin is in such a range, the bulk strength of the die bonding film is maintained, and the fluidity of the adhesive composition when forming the die bonding film tends to be easily ensured.

[0038] The content of component (c) may be 1 mass % or more, 3 mass % or more, or 5 mass % or more, based on the total amount of the die bonding film (or the total amount of solids in the adhesive varnish described below), and may be 15 mass % or less, 12 mass % or less, or 10 mass % or less.

[0039] When component (c) includes a liquid epoxy resin, the mass ratio of the amount of the liquid epoxy resin to the total amount of component (c) (amount (mass) of liquid epoxy resin / total amount (total mass) of components (c)) may be, in percentage, 20% or more, 30% or more, 40% or more, or 50% or more, and may be 100% or less, 90% or less, 80% or less, or 70% or less.

[0040] Component (d): Curing Agent Component (d) may be a phenolic resin that can serve as a curing agent for epoxy resins. Any phenolic resin can be used without particular limitation as long as it has a phenolic hydroxyl group in the molecule. Examples of phenolic resins include novolak-type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and / or naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthalene with a compound having an aldehyde group such as formaldehyde, under an acidic catalyst; allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolak, and phenol aralkyl resins, naphthol aralkyl resins, biphenyl aralkyl-type phenolic resins, and phenyl aralkyl-type phenolic resins synthesized from phenols such as phenol and / or naphthols with dimethoxy-para-xylene or bis(methoxymethyl)biphenyl.

[0041] The hydroxyl equivalent of the phenolic resin may be 40 to 300 g / eq, 70 to 290 g / eq, or 100 to 280 g / eq. When the hydroxyl equivalent of the phenolic resin is 40 g / eq or more, the storage modulus of the film tends to be further improved, and when it is 300 g / eq or less, defects due to the generation of foaming, outgassing, etc. can be prevented.

[0042] From the viewpoint of curability, the ratio of the epoxy equivalent of the epoxy resin (c) to the hydroxyl equivalent of the phenolic resin (d) (epoxy equivalent of the epoxy resin (c) / hydroxyl equivalent of the phenolic resin (d)) may be 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 / 0.40, or 0.45 / 0.55 to 0.55 / 0.45. When the equivalent ratio is 0.30 / 0.70 or more, more sufficient curability tends to be obtained. When the equivalent ratio is 0.70 / 0.30 or less, excessive viscosity increase can be prevented, and more sufficient fluidity can be obtained.

[0043] The content of component (d) may be 1 mass% or more, 3 mass% or more, or 5 mass% or more, based on the total amount of the die bonding film (or the total amount of solids in the adhesive varnish described below), and may be 15 mass% or less, 12 mass% or less, or 10 mass% or less.

[0044] Component (e): Elastomer Examples of component (e) include acrylic resins (including acrylic rubber), urethane resins (including urethane rubber), silicone resins (including silicone rubber), and styrene-based elastomers. Component (e) may be any of these resins having a crosslinkable functional group, or may be an acrylic resin having a crosslinkable functional group. Here, the acrylic resin refers to a polymer containing a structural unit derived from a (meth)acrylic acid ester. The acrylic resin may be a polymer containing a structural unit derived from a (meth)acrylic acid ester having a crosslinkable functional group such as an epoxy group, an alcoholic or phenolic hydroxyl group, or a carboxy group. The acrylic resin may also be an acrylic rubber, such as a copolymer of a (meth)acrylic acid ester and acrylonitrile.

[0045] Commercially available acrylic resins include, for example, SG-P3, SG-70L, SG-708-6, WS-023 EK30, and SG-280 EK23 (all manufactured by Nagase ChemteX Corporation).

[0046] The glass transition temperature (Tg) of component (e) may be −50 to 50°C or −30 to 20°C. When the Tg of the acrylic resin is −50°C or higher, the tackiness of the die bonding film tends to be reduced, thereby further improving handleability. When the Tg of the acrylic resin is 50°C or lower, the fluidity of the adhesive composition when forming the die bonding film tends to be more sufficiently ensured. Here, the Tg of component (e) means the value measured using a DSC (differential scanning calorimeter) (for example, Thermo Plus 2, product name, manufactured by Rigaku Corporation).

[0047] The weight average molecular weight (Mw) of component (e) may be 50,000 to 1.6 million, 100,000 to 1.4 million, or 300,000 to 1.2 million. When component (e) has an Mw of 50,000 or more, the film-forming properties tend to be better. When component (e) has an Mw of 1.6 million or less, the fluidity of the adhesive composition when forming a die-bonding film tends to be better. The Mw is a value measured by gel permeation chromatography (GPC) and converted using a calibration curve based on standard polystyrene.

[0048] The measurement device and conditions for measuring the Mw of component (e) are, for example, as follows: Pump: L-6000 (manufactured by Hitachi, Ltd.) Column: A column consisting of Gelpack GL-R440 (manufactured by Resonac Corporation), Gelpack GL-R450 (manufactured by Resonac Corporation), and Gelpack GL-R400M (manufactured by Resonac Corporation) (each 10.7 mm (diameter) x 300 mm) connected in this order Eluent: Tetrahydrofuran (hereinafter referred to as "THF") Sample: A solution prepared by dissolving 120 mg of sample in 5 mL of THF Flow rate: 1.75 mL / min

[0049] The content of component (e) may be 1 mass% or more, 3 mass% or more, or 5 mass% or more, based on the total amount of the die bonding film (or the total amount of solids in the adhesive varnish described below), and may be 15 mass% or less, 12 mass% or less, or 10 mass% or less.

[0050] Component (f): Curing Accelerator The die bonding film 10A may further contain a curing accelerator (component (f)). When the die bonding film contains component (f), it tends to be able to achieve a better balance between adhesiveness and connection reliability. Examples of component (f) include imidazoles and their derivatives, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. Among these, component (f) may be imidazoles and their derivatives from the viewpoint of reactivity.

[0051] Examples of imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-methylimidazole.

[0052] The content of component (f) may be 0.001 to 1 mass % based on the total amount of the die bonding film (or the total solid content of the adhesive varnish described below). When the content of component (f) is in this range, it tends to be possible to achieve a better balance between adhesiveness and connection reliability.

[0053] The die bonding film 10A may further contain other components in addition to components (a) to (f), such as a coupling agent, an antioxidant, a rheology control agent, a leveling agent, etc. Examples of coupling agents include 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane. The content of the other components may be 0.01 to 3 mass% based on the total amount of the die bonding film.

[0054] [Method for manufacturing die-bonding film] The die-bonding film 10A shown in FIG. 1 can be obtained by a method comprising: a first step of preparing a raw material varnish containing component (a) (silver-containing particles produced by a reduction method or silver-containing particles surface-treated with a surface treatment agent), component (b), and an organic solvent; a second step of mixing the raw material varnish to obtain an adhesive varnish; and a third step of applying the adhesive varnish to a support film and removing the organic solvent to obtain a die-bonding film.

[0055] The first step is to prepare a raw varnish containing component (a) (silver-containing particles produced by a reduction method or silver-containing particles surface-treated with a surface treatment agent), component (b), and an organic solvent.

[0056] The organic solvent is not particularly limited as long as it can dissolve components other than component (a). Examples of organic solvents include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Among these, the organic solvent may be toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone from the viewpoints of solubility and boiling point. The solid content concentration in the raw varnish may be 10 to 80 mass % based on the total amount of the raw varnish.

[0057] The raw varnish can be obtained, for example, by adding each component to a container used in a mixer. In this case, the order of adding each component is not particularly limited and can be set appropriately depending on the properties of each component.

[0058] The second step is a step of mixing the raw varnishes to obtain an adhesive varnish.

[0059] Mixing can be carried out using an appropriate combination of conventional mixers such as a Homo Disper, a Three-One Motor, a mixing rotor, a planetary rotor, or a Raikai mixer. The mixer may be equipped with a heating device such as a heater unit that can control the temperature conditions of the raw material varnish (or adhesive varnish). When a Homo Disper is used for mixing, the rotation speed of the Homo Disper may be 4,000 rpm or more.

[0060] The second step may be a step of mixing the raw material varnish under a temperature condition of 50°C or higher. The mixing temperature may be adjusted using heating equipment, heat-retaining equipment, or the like, as necessary. When the mixing temperature is 50°C or higher, for example, the obtained die bonding film is likely to form a sintered body of component (a) in the cured product (C stage) state after the curing treatment, and the thermal conductivity of the die bonding film can be further improved. The mixing temperature may be 55°C or higher, 60°C or higher, 65°C or higher, or 70°C or higher. The upper limit of the mixing temperature may be, for example, 120°C or lower, 110°C or lower, 100°C or lower, 90°C or lower, or 80°C or lower. The mixing time may be, for example, 1 minute or more, 5 minutes or more, 10 minutes or more, or 20 minutes or more, and may be 80 minutes or less, 60 minutes or less, or 40 minutes or less.

[0061] The components (c), (d), (e), (f), and other components can be independently added to the raw varnish or adhesive varnish at any stage, depending on the properties of each component. For example, a raw varnish further containing these components may be prepared in a first step, and the raw varnishes may be mixed in a second step to obtain an adhesive varnish containing the components (a), (b), (c), (d), (e), (f), and other components. Alternatively, a raw varnish may be prepared in a first step, and the raw varnishes may be mixed in a second step, and these components may be added to the mixed raw varnish to obtain an adhesive varnish containing the components (a), (b), (c), (d), (e), (f), and other components. Furthermore, for example, a raw varnish further containing components (c) and (d) may be prepared in the first step, and the raw varnishes may be mixed in the second step, followed by adding components (e), (f), and other components to the mixed raw varnish to obtain an adhesive varnish containing components (a), (b), (c), (d), (e), (f), and other components. When at least one component selected from the group consisting of components (c), (d), (e), (f), and other components is added to the mixed raw varnish in the second step, the mixed varnish may be mixed, for example, at a temperature below 50°C (e.g., room temperature (25°C)) after addition of the component. In this case, the mixing may be performed at room temperature (25°C) for 0.1 to 48 hours.

[0062] In this way, an adhesive varnish containing the desired components can be obtained. The obtained adhesive varnish may be subjected to vacuum degassing or the like to remove air bubbles therein.

[0063] The content of component (a) is 70% by mass or more, based on the total solid content of the adhesive varnish. In this specification, the solid content of the adhesive varnish means the total amount of components other than the organic solvent. The content of component (a) may be 72% by mass or more, 74% by mass or more, or 75% by mass or more, based on the total solid content of the adhesive varnish, or may be 90% by mass or less, 85% by mass or less, or 80% by mass or less.

[0064] The third step is a step of applying an adhesive varnish to the support film 20 and removing the organic solvent to obtain the die bonding film 10A.

[0065] The support film 20 is not particularly limited, and examples thereof include films of polytetrafluoroethylene, polyethylene, polypropylene, polymethylpentene, polyethylene terephthalate, polyimide, etc. The support film may be subjected to a release treatment. The thickness of the support film 20 may be, for example, 10 to 200 μm or 20 to 170 μm.

[0066] The adhesive varnish can be applied to the support film 20 by any known method, such as knife coating, roll coating, spray coating, gravure coating, bar coating, curtain coating, or the like.

[0067] The organic solvent after applying the adhesive varnish to the support film can be removed by heat drying. The heat drying conditions are not particularly limited as long as the organic solvent used is sufficiently volatilized, but for example, the heat drying temperature may be 50 to 200°C and the heat drying time may be 0.1 to 30 minutes. Heat drying may be performed stepwise at different heat drying temperatures or heat drying times.

[0068] The thickness of the die bonding film 10A can be adjusted appropriately depending on the application, but may be, for example, 3 to 200 μm. When the thickness of the die bonding film 10A is 3 μm or more, the adhesive strength with the semiconductor wafer tends to be sufficient, and when it is 200 μm or less, the thermal conductivity tends to be sufficient. The thickness of the die bonding film 10A may be 5 to 100 μm or 10 to 50 μm from the viewpoints of adhesive strength and thinning of the semiconductor device.

[0069] The thermal conductivity (25°C ± 1°C) of the die bonding film 10A after thermal curing at 170°C for 3 hours (C-stage state) may be 4.0 W / (m·K) or more. A thermal conductivity of 4.0 W / (m·K) or more tends to improve the heat dissipation properties of the semiconductor device. The thermal conductivity may be 4.5 W / (m·K) or more, 5.0 W / (m·K) or more, 5.5 W / (m·K) or more, or 6.0 W / (m·K) or more. The upper limit of the thermal conductivity (25°C ± 1°C) of the die bonding film 10A in the C-stage state is not particularly limited, but may be 30 W / (m·K) or less.

[0070] The thermal conductivity (25°C ± 1°C) of the die bonding film 10A after thermal curing at 170°C for 3 hours (C-stage state) can be measured, for example, by the following method. First, the die bonding film is cut to a predetermined size, and a predetermined number of film pieces are prepared so that the thickness when laminated will be 200 μm. For example, when using a die bonding film with a thickness of 25 μm, eight film pieces are prepared. When using a die bonding film with a thickness of 10 μm, 20 film pieces are prepared. These film pieces are laminated using a rubber roll on a hot plate at 70°C to prepare a laminate with a thickness of 200 μm. Next, each laminate is thermally cured at 170°C for 3 hours in a clean oven (manufactured by Espec Corporation) to obtain a sample in a C-stage state. The obtained sample is cut into 1 cm x 1 cm pieces, and this is used as a thermal conductivity measurement film, and the thermal conductivity is measured under the following measurement items / conditions.

[0071] (Calculation of Thermal Conductivity) The thermal conductivity λ of the film for measuring thermal conductivity in the thickness direction is calculated by the following formula: Thermal conductivity λ (W / (m·K)) = Thermal diffusivity α (m ２ / s) x specific heat Cp (J / (kg・K)) x density ρ (g / cm ３ )

[0072] The thermal diffusivity α, specific heat Cp, and density ρ are measured by the following methods: A high thermal conductivity λ means that the semiconductor device has better heat dissipation properties.

[0073] (Measurement of thermal diffusivity α) A measurement sample is prepared by blackening both sides of a thermal conductivity measurement film with graphite spray. The thermal diffusivity α of the measurement sample is determined by the laser flash method (xenon flash method) using, for example, the following measurement device under the following conditions: Measurement device: thermal diffusivity measurement device (manufactured by Netsch Japan Co., Ltd., product name: LFA447 nanoflash) Pulse width of pulsed light irradiation: 0.1 ms Applied voltage of pulsed light irradiation: 236 V Measurement sample treatment: both sides of the thermal conductivity measurement film are blackened with graphite spray Measurement atmosphere temperature: 25°C ± 1°C

[0074] (Measurement of specific heat Cp (25°C)) The specific heat Cp (25°C) of the film for thermal conductivity measurement is determined, for example, by differential scanning calorimetry (DSC) using the following measuring device under the following conditions: Measuring device: differential scanning calorimetry device (manufactured by PerkinElmer Japan Co., Ltd., trade name: Pyris1) Reference material: sapphire Heating rate: 10°C / min Heating temperature range: room temperature (25°C) to 60°C

[0075] (Measurement of Density ρ) The density ρ of the thermal conductivity measurement film is measured by the Archimedes method using, for example, the following measurement device under the following conditions: Measurement device: Electronic hydrometer (manufactured by Alpha Mirage Co., Ltd., product name: SD200L) Water temperature: 25°C

[0076] The die bonding film contains components (a) and (b), which can improve the thermal conductivity and, as a result, the heat dissipation of the semiconductor device. Therefore, the die bonding film can be suitably used as a dicing / die bonding integrated film in combination with a dicing tape (dicing film) having a pressure-sensitive adhesive layer.

[0077] [Dicing and die bonding integrated film] Figure 2 is a schematic cross-sectional view showing one embodiment of a dicing and die bonding integrated film. The dicing and die bonding integrated film 100 shown in Figure 2 includes a dicing tape 50 (dicing film) including a base layer 40 and a pressure-sensitive adhesive layer 30 provided on the base layer 40, and an adhesive layer 10 consisting of a die bonding film 10A provided on the pressure-sensitive adhesive layer 30 of the dicing tape 50. The dicing and die bonding integrated film 100 may be in the form of a film, sheet, tape, or the like. The dicing and die bonding integrated film 100 may also include a support film 20 on the surface of the adhesive layer 10 opposite the pressure-sensitive adhesive layer 30.

[0078] Examples of the base material layer 40 in the dicing tape 50 include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. Furthermore, the base material layer 40 may be subjected to surface treatment such as primer application, UV treatment, corona discharge treatment, polishing treatment, and etching treatment, as needed.

[0079] The adhesive layer 30 in the dicing tape 50 is not particularly limited as long as it has sufficient adhesive strength to prevent the semiconductor chips from scattering during dicing and low adhesive strength to prevent damage to the semiconductor chips in the subsequent semiconductor chip pick-up process, and any adhesive layer conventionally known in the field of dicing tapes can be used. The adhesive layer 30 may be an adhesive layer made of a non-UV-curable adhesive, or an adhesive layer made of a UV-curable adhesive. When the adhesive layer is an adhesive layer made of a UV-curable adhesive, the adhesiveness of the adhesive layer can be reduced by irradiating it with UV light.

[0080] The thickness of the dicing tape 50 (base layer 40 and adhesive layer 30) may be 60 to 150 μm or 70 to 130 μm from the viewpoints of economy and film handling.

[0081] 2 can be obtained by a manufacturing method including the steps of preparing a die bonding film 10A and a dicing tape 50 including a base layer 40 and an adhesive layer 30 provided on the base layer 40, and bonding the die bonding film 10A to the adhesive layer 30 of the dicing tape 50. A known method can be used as the method for bonding the die bonding film 10A to the adhesive layer 30 of the dicing tape 50.

[0082] [Semiconductor Device and Manufacturing Method Thereof] Figure 3 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a semiconductor device, in which Figures 3(a), 3(b), 3(c), 3(d), 3(e), and 3(f) are cross-sectional views showing each step. The method for manufacturing a semiconductor device includes a step of attaching a semiconductor wafer W to the adhesive layer 10 of the above-mentioned dicing / die bonding integrated film 100 (wafer lamination step, see Figures 3(a) and (b)), a step of singulating the semiconductor wafer W and the adhesive layer 10 (dicing step, see Figure 3(c)), a step of irradiating the adhesive layer 30 (through the base layer 40) with ultraviolet light (ultraviolet irradiation step, see Figure 3(d)), a step of picking up the semiconductor chip 60 with adhesive layer piece from the dicing tape 50 (the adhesive layer 30 of the dicing tape 50) (pickup step, see Figure 3(e)), a step of adhering the semiconductor chip 60 with adhesive layer piece to a support member 80 through the adhesive layer piece 10a (semiconductor chip adhering step, see Figure 3(f)), and a step of thermally curing the adhesive layer piece 10a in the semiconductor chip 60 with adhesive layer piece adhered to the support member 80, if necessary (thermal curing step).

[0083] <Wafer Lamination Process> In this process, first, the dicing and die bonding integrated film 100 is placed in a predetermined device. Next, the front surface Ws of the semiconductor wafer W is attached to the adhesive layer 10 of the dicing and die bonding integrated film 100 (see FIGS. 3(a) and 3(b)). The circuit surface of the semiconductor wafer W may be provided on the surface opposite to the front surface Ws.

[0084] Examples of the semiconductor wafer W include single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

[0085] <Dicing Process> In this process, the semiconductor wafer W and the adhesive layer 10 are diced into individual pieces (see FIG. 3(c)). At this time, a part of the pressure-sensitive adhesive layer 30, or the entire pressure-sensitive adhesive layer 30 and a part of the base material layer 40 may be diced into individual pieces. In this way, the dicing and die-bonding integrated film 100 also functions as a dicing sheet.

[0086] <Ultraviolet Light Irradiation Step> When the adhesive layer 30 is an adhesive layer made of an ultraviolet-curable adhesive, the method for manufacturing a semiconductor device may include an ultraviolet light irradiation step. In this step, ultraviolet light is irradiated onto the adhesive layer 30 (through the base layer 40) (see FIG. 3(d)). The wavelength of the ultraviolet light may be 200 to 400 nm. The ultraviolet light irradiation conditions are an illuminance and an irradiation amount of 30 to 240 mW / cm, respectively. ２ and 50 to 500 mJ / cm ２ may be in the range of

[0087] <Pickup Process> In this process, the base layer 40 is expanded to separate the individual semiconductor chips 60 with adhesive layer pieces from each other, and the semiconductor chips 60 with adhesive layer pieces pushed up by needles 72 from the base layer 40 side are sucked with a suction collet 74 and picked up from the adhesive layer 30a (see FIG. 3(e)). The semiconductor chips 60 with adhesive layer pieces include a semiconductor chip Wa and an adhesive layer piece 10a. The semiconductor chip Wa is obtained by dividing the semiconductor wafer W, and the adhesive layer piece 10a is obtained by dividing the adhesive layer 10. The adhesive layer 30a is obtained by dividing the adhesive layer 30. The adhesive layer 30a may remain on the base layer 40 after the semiconductor chips 60 with adhesive layer pieces are picked up. In this process, expanding the base layer 40 is not necessarily required, but expanding the base layer 40 can further improve pickup properties.

[0088] The amount of push-up by the needle 72 can be set as appropriate. Furthermore, from the viewpoint of ensuring sufficient pick-up capability even for ultra-thin wafers, for example, two- or three-stage push-up may be performed. Furthermore, the semiconductor chip 60 with the adhesive layer piece attached may be picked up by a method other than the method using the suction collet 74.

[0089] <Semiconductor Chip Bonding Step> In this step, the picked-up semiconductor chip 60 with adhesive layer piece is bonded to the support member 80 via the adhesive layer piece 10a by thermocompression bonding (see FIG. 3(f)). A plurality of semiconductor chips 60 with adhesive layer piece may be bonded to the support member 80.

[0090] The heating temperature in the thermocompression bonding may be, for example, 80 to 160° C. The load in the thermocompression bonding may be, for example, 5 to 15 N. The heating time in the thermocompression bonding may be, for example, 0.5 to 20 seconds.

[0091] <Thermal Curing Step> In this step, the adhesive layer piece 10a of the semiconductor chip 60 with adhesive layer piece bonded to the support member 80 is thermally cured. By (further) thermally curing the adhesive layer piece 10a or the cured adhesive layer piece 10ac bonding the semiconductor chip Wa to the support member 80, a stronger adhesive fixation is possible. Furthermore, (further) thermally curing the adhesive layer piece 10a or the cured adhesive layer piece 10ac tends to make it easier to obtain a sintered body of component (a). When performing thermal curing, pressure may be applied simultaneously to harden the adhesive layer piece 10a. The heating temperature in this step can be appropriately changed depending on the constituent components of the adhesive layer piece 10a. The heating temperature may be, for example, 60 to 200°C, 90 to 190°C, or 120 to 180°C. The heating time may be 30 minutes to 5 hours, 1 to 3 hours, or 2 to 3 hours. The temperature or pressure may be changed stepwise.

[0092] The adhesive layer piece 10a can be cured through a semiconductor chip bonding process or a thermal curing process to become a cured adhesive layer piece 10ac. The cured adhesive layer piece 10ac can contain a sintered body of component (a). Therefore, the resulting semiconductor device can have excellent heat dissipation properties.

[0093] The method for manufacturing a semiconductor device may, as necessary, include a step of electrically connecting the tip of the terminal portion (inner lead) of the support member to an electrode pad on the semiconductor chip with a bonding wire (wire bonding step). Examples of bonding wires that can be used include gold wire, aluminum wire, and copper wire. The temperature during wire bonding may be within a range of 80 to 250°C or 80 to 220°C. The heating time may be from a few seconds to a few minutes. Wire bonding may be performed by combining ultrasonic vibration energy and compression energy due to applied pressure while the substrate is heated within the above temperature range.

[0094] The method for manufacturing a semiconductor device may optionally include a step of encapsulating the semiconductor chip with an encapsulant (encapsulation step). This step is performed to protect the semiconductor chip or bonding wires mounted on the support member. This step can be performed by molding the encapsulating resin (encapsulation resin) in a mold. The encapsulation resin may be, for example, an epoxy-based resin. The heat and pressure during encapsulation bury the support member and residue, preventing peeling due to air bubbles at the adhesive interface.

[0095] The method for manufacturing a semiconductor device may, if necessary, include a step (post-curing step) of completely curing the encapsulating resin that is insufficiently cured in the encapsulating step. Even if the adhesive layer pieces are not thermally cured in the encapsulating step, in this step, the adhesive layer pieces can be thermally cured together with the curing of the encapsulating resin, thereby enabling adhesive fixation. The heating temperature in this step can be appropriately set depending on the type of encapsulating resin, and may be, for example, in the range of 165 to 185°C, and the heating time may be approximately 0.5 to 8 hours.

[0096] The method for manufacturing a semiconductor device may optionally include a step of heating the semiconductor chip with adhesive layer attached to the support member using a reflow furnace (heating and melting step). In this step, the resin-encapsulated semiconductor device may be surface-mounted on the support member. Examples of surface-mounting methods include reflow soldering, in which solder is first supplied onto a printed wiring board, then heated and melted using hot air or the like to perform soldering. Examples of heating methods include hot air reflow and infrared reflow. The heating method may involve heating the entire device or localized heating. The heating temperature may be, for example, within the range of 240 to 280°C.

[0097] FIG. 4 is a schematic cross-sectional view showing one embodiment of a semiconductor device. The semiconductor device 200 shown in FIG. 4 includes a semiconductor chip Wa, a support member 80 on which the semiconductor chip Wa is mounted, and an adhesive member 12. The adhesive member 12 is provided between the semiconductor chip Wa and the support member 80 and bonds the semiconductor chip Wa to the support member 80. The adhesive member 12 is a cured product of a die bonding film (a cured product 10ac of an adhesive layer piece). Connection terminals (not shown) of the semiconductor chip Wa may be electrically connected to external connection terminals (not shown) via wires 70. The semiconductor chip Wa may be encapsulated by an encapsulant layer 92 formed from an encapsulant. Solder balls 94 may be formed on the surface of the support member 80 opposite the surface 80A for electrical connection to an external substrate (motherboard) (not shown).

[0098] The semiconductor chip Wa may be, for example, an IC (integrated circuit), etc. Examples of the support member 80 include lead frames such as a 42 alloy lead frame and a copper lead frame, plastic films such as polyimide resin and epoxy resin, modified plastic films obtained by impregnating and curing a glass nonwoven fabric or the like with a plastic such as polyimide resin or epoxy resin, and ceramics such as alumina.

[0099] The semiconductor device 200 has excellent heat dissipation properties because it includes the cured product of the die bonding film as the adhesive member.

[0100] The present disclosure will be specifically described below based on examples, but the present disclosure is not limited to these examples.

[0101] (Example 1 and Comparative Examples 1 and 2) [Production of Die-Bonding Film] <Preparation of Adhesive Varnish> A raw varnish was prepared by adding cyclohexanone as an organic solvent to component (a), component (b) or (b'), component (c), component (d), and component (e) according to the symbols and composition ratios (unit: parts by mass) shown in Table 1. The raw varnish was stirred at 4,000 rpm for 20 minutes using a Homo Disper (T.K. HOMO MIXER MARK II, manufactured by Tajima Chemical Machinery Co., Ltd.) at a mixing temperature of 70°C. Next, the raw varnish was left to cool to 20-30°C, after which component (f) and component (g) were added to the raw varnish, and the mixture was stirred overnight at 250 rpm using a Three-One motor. In this manner, adhesive varnishes of Example 1 and Comparative Examples 1 and 2 were prepared, each having a total content of component (a), component (b) or (b'), component (c), component (d), component (e), component (f), and component (g) of 61 to 62 mass %.

[0102] The symbols of each component in Table 1 have the following meanings.

[0103] Component (a): Silver-containing particles produced by a reduction method (silver-containing particles surface-treated (coated) with a surface treatment agent) (a-1) Silver particles AG-3-1F (trade name, manufactured by DOWA Electronics Co., Ltd., shape: spherical, average particle size (laser 50% particle size (D ５０ )): 1.4 μm)

[0104] Component (b): Compound represented by formula (1) (b-1) 2-methylglutaric acid

[0105] Component (b'): Compound other than the compound represented by formula (1) (b'-1) 3-methylglutaric acid (b'-2) 3,3-tetramethylene glutaric acid

[0106] (c) Component: Thermosetting Resin (c-1) N-500P-10 (trade name, manufactured by DIC Corporation, cresol novolac type epoxy resin, epoxy equivalent: 204 g / eq, softening point: 84°C) (c-2) EXA-830CRP (trade name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 159 g / eq, liquid at 25°C)

[0107] Component (d): Curing agent (d-1) MEH-7800M (trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), phenylaralkyl phenolic resin, hydroxyl group equivalent: 174 g / eq, softening point: 80°C)

[0108] (e) Component: Elastomer (e-1) SG-P3 solvent-change product (trade name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight-average molecular weight: 800,000, Tg: 12°C)

[0109] Component (f): Curing accelerator (f-1) 1B2MZ (trade name, manufactured by Shikoku Chemicals Corporation, 1-benzyl-2-methylimidazole)

[0110] Component (g): Coupling agent (g-1) Z-6119 (trade name, manufactured by Dow-Toray Industries, Inc., 3-ureidopropyltriethoxysilane)

[0111] <Preparation of Die-Bonding Film> Die-bonding films were prepared using each of the adhesive varnishes described above. Each adhesive varnish was vacuum degassed, and then coated onto a support film, a polyethylene terephthalate (PET) film (thickness: 38 μm) that had been subjected to a release treatment. The coated adhesive varnish was heated and dried in two stages at different temperatures, first at 90°C for 5 minutes and then at 130°C for 5 minutes, to obtain die-bonding films of Example 1 and Comparative Examples 1 and 2, each having a thickness of 25 μm, in a B-stage state on the support film.

[0112] <Calculation of Volume %> The content (volume %) of the component (a) is calculated by multiplying the density of the die bonding film by x (g / cm ３ ), (a) the density of the component is y (g / cm ３), and the mass proportion of the component (a) in the die bonding film was defined as z (mass%), and the mass proportion was calculated from the following formula (I). The mass proportion of the component (a) in the die bonding film was determined by thermogravimetric analysis using a thermogravimetric differential thermal analyzer (TG-DTA). The densities of the die bonding film and the component (a) were determined by measuring the mass and specific gravity using a hydrometer. Content (volume %) of the component (a) = (x / y) x z (I) TG-DTA measurement conditions: temperature range 30 to 600°C (heating rate 30°C / min), maintained at 600°C for 20 minutes Air flow rate: 300 mL / min Thermogravimetric differential thermal analyzer: TG / DTA220, manufactured by Seiko Instruments Inc. Hydrometer: EW-300SG, manufactured by Alpha Mirage Co., Ltd.

[0113] [Evaluation of Die Bonding Film (Measurement of Thermal Conductivity)] (Preparation of Film for Thermal Conductivity Measurement) The die bonding film was cut to a predetermined size, and eight film pieces (thickness: 25 μm) were prepared for the die bonding films of Example 1 and Comparative Examples 1 and 2. Next, these film pieces were laminated using a rubber roll on a hot plate at 70°C to prepare a laminate with a thickness of 200 μm. Next, each laminate was thermally cured at 170°C for 3 hours in a clean oven (manufactured by Espec Corporation) to obtain a sample in a C-stage state. The prepared sample was cut into a 1 cm x 1 cm piece, and this was used as a film for thermal conductivity measurement. The thermal conductivity was measured under the following measurement items / conditions. The results are shown in Table 1. Note that the values ​​shown in Table 1 are relative values ​​when the thermal conductivity value of Comparative Example 1 is set to 100.

[0114] (Calculation of Thermal Conductivity) The thermal conductivity λ of the film for measuring thermal conductivity in the thickness direction was calculated by the following formula: Thermal conductivity λ (W / (m·K)) = Thermal diffusivity α (m ２ / s) x specific heat Cp (J / (kg・K)) x density ρ (g / cm ３ The thermal diffusivity α, specific heat Cp, and density ρ were measured by the following methods: A high thermal conductivity λ means that the semiconductor device has better heat dissipation properties.

[0115] (Measurement of thermal diffusivity α) Both sides of a thermal conductivity measurement film were blackened with graphite spray to prepare a measurement sample. The thermal diffusivity α of the measurement sample was determined by the laser flash method (xenon flash method) using the following measurement device under the following conditions: Measurement device: thermal diffusivity measurement device (manufactured by Netsch Japan Co., Ltd., product name: LFA447 nanoflash) Pulse width of pulsed light irradiation: 0.1 ms Applied voltage of pulsed light irradiation: 236 V Measurement sample treatment: Both sides of the thermal conductivity measurement film were blackened with graphite spray Measurement atmosphere temperature: 25°C ± 1°C

[0116] (Measurement of specific heat Cp (25°C)) The specific heat Cp (25°C) of the film for thermal conductivity measurement was determined by differential scanning calorimetry (DSC) using the following measuring device under the following conditions: Measuring device: differential scanning calorimetry device (manufactured by PerkinElmer Japan Co., Ltd., trade name: Pyris1) Reference material: sapphire Heating rate: 10°C / min Heating temperature range: room temperature (25°C) to 60°C

[0117] (Measurement of Density ρ) The density ρ of the thermal conductivity measurement film was measured by the Archimedes method using the following measurement device under the following conditions: Measurement device: Electronic hydrometer (manufactured by Alpha Mirage Co., Ltd., product name: SD200L) Water temperature: 25°C

[0118]

[0119] As shown in Table 1, the die bonding film of Example 1, which contained the compound represented by formula (1), was superior in thermal conductivity to the die bonding films of Comparative Examples 1 and 2, which did not contain the compound represented by formula (1). These results confirmed that the integrated dicing and die bonding film of the present disclosure can be used to manufacture semiconductor devices with excellent heat dissipation properties.

[0120] 10...adhesive layer, 10A...die bonding film, 10a...adhesive layer piece, 10ac...cured product of adhesive layer piece, 12...adhesive member, 20...support film, 30, 30a...pressure-sensitive adhesive layer, 40...base material layer, 50...dicing tape, 60...semiconductor chip with adhesive layer piece, 70...wire, 72...needle, 74...suction collet, 80...support member, 92...sealant layer, 94...solder ball, 100...dicing and die bonding integrated film, 200...semiconductor device, W...semiconductor wafer, Wa...semiconductor chip.

Claims

1. A method for producing a die bonding film, comprising: a first step of preparing a raw varnish containing silver-containing particles produced by a reduction method, a compound represented by formula (1), and an organic solvent; a second step of mixing the raw varnish to obtain an adhesive varnish; and a third step of applying the adhesive varnish to a support film and removing the organic solvent to obtain a die bonding film, wherein the content of the silver-containing particles is 70 mass% or more based on the total solid content of the adhesive varnish. [In formula (1), R １ , R ２ , R ３ , and R ４ each independently represents a hydrogen atom, a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom. １ , R ２ , R ３ , and R ４ At least one of is a halogen atom, a methyl group optionally substituted with a halogen atom, or an ethyl group optionally substituted with a halogen atom.] 2. A method for manufacturing a die bonding film, comprising: a first step of preparing a raw varnish containing silver-containing particles surface-treated with a surface treatment agent, a compound represented by formula (1), and an organic solvent; a second step of mixing the raw varnish to obtain an adhesive varnish; and a third step of applying the adhesive varnish to a support film and removing the organic solvent to obtain a die bonding film, wherein the content of the silver-containing particles is 70 mass% or more based on the total solid content of the adhesive varnish. [In formula (1), R １ , R ２ , R ３ , and R ４ each independently represents a hydrogen atom, a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom. １ , R ２ , R ３ , and R ４ At least one of is a halogen atom, a methyl group optionally substituted with a halogen atom, or an ethyl group optionally substituted with a halogen atom.] 3. The method for producing a die bonding film according to claim 1 or 2, wherein the second step is a step of mixing the raw varnish at a temperature of 50°C or higher.

4. The method for producing a die bonding film according to claim 1 or 2, wherein the raw varnish further contains a thermosetting resin, a curing agent, and an elastomer.

5. The method for producing a die bonding film according to claim 4, wherein the thermosetting resin comprises an epoxy resin that is liquid at 25°C.

6. A method for producing a die bonding film according to claim 1 or 2, wherein the second step is a step of adding a thermosetting resin, a curing agent, and an elastomer to the mixed raw varnish to obtain an adhesive varnish further containing these.

7. The method for producing a die bonding film according to claim 6, wherein the thermosetting resin comprises an epoxy resin that is liquid at 25°C.

8. A method for manufacturing a dicing and die bonding integrated film, comprising the steps of: preparing a dicing tape having a base layer and an adhesive layer provided on the base layer; and bonding a die bonding film manufactured by the die bonding film manufacturing method described in claim 1 or 2 to the adhesive layer of the dicing tape, to form an adhesive layer made of the die bonding film on the adhesive layer.

9. A method for manufacturing a semiconductor device, comprising the steps of: attaching the adhesive layer of a dicing-die bonding integrated film manufactured by the method for manufacturing a dicing-die bonding integrated film described in claim 8 to a semiconductor wafer; singulating the semiconductor wafer and the adhesive layer; picking up a semiconductor chip with an adhesive layer piece from the dicing tape; and adhering the semiconductor chip with an adhesive layer piece to a support member via the adhesive layer piece.

10. A die bonding film comprising silver-containing particles produced by a reduction method and a compound represented by formula (1), wherein the content of the silver-containing particles is 70 mass% or more based on the total amount of the die bonding film. [In formula (1), R １ , R ２ , R ３ , and R ４ each independently represents a hydrogen atom, a halogen atom, a methyl group which may be substituted with a halogen atom, or an ethyl group which may be substituted with a halogen atom. １ , R ２ , R ３ , and R ４ At least one of is a halogen atom, a methyl group optionally substituted with a halogen atom, or an ethyl group optionally substituted with a halogen atom.] 11. The die bonding film according to claim 10, further comprising a thermosetting resin, a curing agent, and an elastomer.

12. The die bonding film according to claim 11, wherein the thermosetting resin comprises an epoxy resin that is liquid at 25°C.

13. A dicing and die bonding integrated film comprising: a dicing tape having a base layer and an adhesive layer provided on the base layer; and an adhesive layer made of the die bonding film according to any one of claims 10 to 12, disposed on the adhesive layer of the dicing tape.

14. A semiconductor device comprising: a semiconductor chip; a support member on which said semiconductor chip is mounted; and an adhesive member provided between said semiconductor chip and said support member and bonding said semiconductor chip to said support member, wherein said adhesive member comprises a cured product of the die bonding film according to any one of claims 10 to 12.

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