Film adhesive, dicing / die attach film, semiconductor device, and production method for same

Abstract

Provided is a film adhesive comprising metal particles, an epoxy resin, a phenolic resin, and an elastomer, wherein the content of the metal particles is not less than 80.0 mass% with respect to the mass of the film adhesive, the epoxy resin contains a first epoxy resin that is liquid at 25°C and a second epoxy resin that is solid at 25°C, and when the content of the metal particles is expressed as 100 mass parts, the content of the first epoxy resin is 4.0-5.5 mass parts.

Description

Film-like adhesive, dicing / die bonding integrated film, semiconductor device, and manufacturing method thereof

[0001] The present disclosure relates to a film adhesive, a dicing and die bonding integrated film, a semiconductor device, and a method for manufacturing the same.

[0002] Conventionally, semiconductor devices are manufactured through the following steps. First, a semiconductor wafer is attached to a dicing adhesive sheet, and the semiconductor wafer is then singulated into semiconductor chips (dicing step). Then, a pickup step, a pressure-bonding step, a die-bonding step, and other steps are performed. Patent Document 1 discloses an adhesive film (a dicing / die-bonding integrated film) that has both the function of fixing a semiconductor wafer in the dicing step and the function of bonding a semiconductor chip to a substrate in the die-bonding step. In the dicing step, the semiconductor wafer and the adhesive layer are singulated to obtain semiconductor chips with adhesive 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 to them, and therefore require excellent heat dissipation properties. Patent Document 2 discloses a film-like adhesive that has higher heat dissipation properties after curing than before curing.

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

[0005] In the manufacturing of semiconductor devices, as semiconductor packages become smaller and more highly integrated, there is a demand for film-like adhesives with high heat dissipation properties to suppress heat generation in semiconductor packages. To achieve high heat dissipation properties, a high amount of filler with high thermal conductivity is required. However, when a large amount of filler is incorporated into a film-like adhesive, a phenomenon occurs in which adhesion to the polyethylene film cover film is reduced. There was a challenge in improving the deterioration of adhesion while maintaining the high heat dissipation performance of the film-like adhesive.

[0006] The present disclosure provides a film adhesive that is useful for manufacturing semiconductor devices with excellent heat dissipation and has excellent adhesion. The present disclosure also provides an integrated dicing and die bonding film that includes the film adhesive, as well as a semiconductor device and a method for manufacturing the same.

[0007] In order to solve the above problem, the inventors optimized the amount of each resin component contained in the film adhesive under conditions in which metal particles were contained, and conducted extensive research focusing on the correlation between various parameters related to the film adhesive and adhesion, resulting in the completion of the following invention.

[0008] The present disclosure relates to the following inventions: [1] A film-like adhesive comprising metal particles, an epoxy resin, a phenolic resin, and an elastomer, wherein the content of the metal particles is 80.0 mass% or more based on the mass of the film-like adhesive, the epoxy resin comprises a first epoxy resin that is liquid at 25°C and a second epoxy resin that is solid at 25°C, and the content of the first epoxy resin is 4.0 to 5.5 mass parts per 100 mass parts of the metal particles. [2] The film-like adhesive according to [1], wherein the content of the first epoxy resin is 1.5 mass parts or more based on the content of the second epoxy resin. [3] The film-like adhesive according to [1] or [2], wherein the content of the metal particles is 26 to 38 volume% based on the volume of the film-like adhesive. [4] The film-like adhesive according to any one of [1] to [3], wherein the metal particles are silver particles. [5] The film-like adhesive according to any one of [1] to [4], wherein the equivalent ratio of the epoxy resin to the phenolic resin is 1.2 or more. [6] The film-like adhesive according to any one of [1] to [5], wherein the thickness is 5 to 40 μm. [7] The film-like adhesive according to any one of [1] to [6], wherein the thermal conductivity at 25°C ± 1°C after thermal curing at 170°C for 3 hours is 7 W / (m·K) or more. [8] An integrated dicing and die bonding film having a laminated structure including, in this order, a base layer, a first adhesive layer, and a second adhesive layer, wherein the second adhesive layer is composed of the film-like adhesive according to any one of [1] to [7]. [9] The integrated dicing and die bonding film according to [8], further comprising a cover film provided so as to cover the second adhesive layer.

[10] 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 is a cured product of the film-like adhesive described in any one of [1] to [7].

[11] A method for manufacturing a semiconductor device, comprising: a step of attaching the second adhesive layer of the dicing and die bonding integrated film described in [8] or [9] to a semiconductor wafer; a step of obtaining a semiconductor chip with an adhesive piece, which is composed of a semiconductor chip and an adhesive piece, by dicing the laminate of the semiconductor wafer and the second adhesive layer; and a step of adhering the semiconductor chip to a support member via the adhesive piece.

[0009] The present disclosure provides a film adhesive that is useful for manufacturing semiconductor devices with excellent heat dissipation properties and has excellent adhesion. The present disclosure also provides an integrated dicing and die bonding film that includes the film adhesive, as well as a semiconductor device and a method for manufacturing the same.

[0010] Fig. 1 is a cross-sectional view schematically showing one embodiment of a film-like adhesive. Fig. 2 is a cross-sectional view schematically showing one embodiment of a dicing / die bonding integrated film. Figs. 3(a) to 3(f) are cross-sectional views schematically showing a series of steps for manufacturing a semiconductor device. Fig. 4 is a cross-sectional view schematically 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] 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 of a certain numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, the upper and lower limits individually described can be arbitrarily combined. Furthermore, in this specification, "(meth)acrylate" means at least one of acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl". Furthermore, "(poly)" means both with and without the "poly" prefix. Furthermore, "A or B" may include either A or B, or may include both. Furthermore, the materials exemplified below may be used alone or in combination of two or more, unless otherwise specified. When a composition contains multiple substances corresponding to each component, the content of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified.

[0013] FIG. 1 is a cross-sectional view schematically illustrating a film-like adhesive according to this embodiment. The film-like adhesive 10A shown in this figure is thermosetting, and reaches a semi-cured (B-stage) state before reaching a fully cured (C-stage) state after a curing process. The film-like adhesive 10A is provided on a support film 20. The film-like adhesive 10A is used, for example, as a die-bonding film used to bond a semiconductor chip to a support member or to bond semiconductor chips together.

[0014] The support film 20 is not particularly limited, but examples thereof include films of polytetrafluoroethylene, polyethylene, polypropylene, polymethylpentene, polyethylene terephthalate, polyimide, etc. The support film 20 may be subjected to a release treatment. The thickness of the support film 20 is, for example, 10 to 200 μm or 20 to 170 μm.

[0015] The film-like adhesive 10A contains metal particles, an epoxy resin, a phenolic resin, and an elastomer, and the metal particle content is 80.0 mass% or more based on the mass of the film-like adhesive. The epoxy resin includes a first epoxy resin that is liquid at 25°C and a second epoxy resin that is solid at 25°C. The first epoxy resin content is 4.0 to 5.5 mass parts per 100 mass parts of the metal particles. By using the first epoxy resin and the second epoxy resin in combination, excellent adhesion of the film-like adhesive can be achieved even when the metal particle content is 80.0 mass% or more. From the viewpoint of achieving even better adhesion, the first epoxy resin content may be 1.5 mass parts or more, 1.5 to 2.0 mass parts, or 1.6 to 1.8 mass parts per 1 mass part of the second epoxy resin. When the content of the metal particles is 100 parts by mass, the content of the second epoxy resin is, for example, 2.0 to 4.0 parts by mass, or may be 2.1 to 3.8 parts by mass, or may be 2.2 to 3.5 parts by mass.

[0016] In addition to the above components, the film-like adhesive 10A may further contain a coupling agent and a curing accelerator. Hereinafter, the metal particles will be referred to as "component (A)," the thermosetting resin as "component (B)," the curing agent as "component (C)," the elastomer as "component (D)," the coupling agent as "component (E)," and the curing accelerator as "component (F)." Each component will be described below.

[0017] Component (A): Metal Particles The metal particles as component (A) are a component that enhances heat dissipation when the film adhesive is applied to a semiconductor device.

[0018] Examples of the component (A) include particles containing metals such as aluminum, nickel, tin, bismuth, indium, zinc, iron, copper, silver, gold, palladium, and platinum. The component (A) may be metal particles composed of one type of metal, or may be metal particles composed of two or more types of metals. Metal particles composed of two or more types of metals may be metal-coated metal particles in which the surface of the metal particles is coated with a metal different from the metal particles. The component (A) may be, for example, conductive particles.

[0019] The conductive particles have an electrical conductivity (0°C) of, for example, 40 x 10 ６ The conductive particles may be metal particles made of a metal having an electrical conductivity (0°C) of 40 x 10 ６ Examples of metals with a solubility of S / m or more include gold (49×10 ６ S / m), silver (67×10 ６ S / m), copper (65×10 ６ The electrical conductivity (0°C) is 45 x 10 ６ S / m or more or 50 x 10 ６ In other words, the conductive particles (or the metal particles as component (A)) are preferably metal particles made of silver and / or copper.

[0020] The conductive particles may be, for example, metal particles composed of a metal having a thermal conductivity (20°C) of 250 W / (m·K) or more. By using such conductive particles, heat dissipation can be further improved. Examples of metals having a thermal conductivity (20°C) of 250 W / (m·K) or more include gold (295 W / (m·K)), silver (418 W / (m·K)), and copper (372 W / (m·K)). The thermal conductivity (20°C) may be 300 W / (m·K) or more or 350 W / (m·K) or more. That is, the conductive particles (or metal particles as component (A)) are preferably metal particles composed of silver and / or copper.

[0021] Component (A) may be silver particles, which have excellent electrical conductivity and thermal conductivity and are resistant to oxidation. The silver particles may be, for example, particles composed of silver (particles composed of silver alone) or silver-coated metal particles in which the surfaces of metal particles (such as copper particles) are coated with silver. Examples of silver-coated metal particles include silver-coated copper particles. Component (A) may be particles composed of silver.

[0022] The silver particles as component (A) are not particularly limited, and examples thereof include silver particles produced by a reduction method (silver particles produced by a liquid-phase (wet) reduction method using a reducing agent), silver particles produced by an atomization method, etc. The silver particles as component (A) may be silver particles produced by a reduction method.

[0023] In a liquid-phase (wet) reduction method using a reducing agent, a surface treatment agent (lubricant) is usually added to prevent aggregation or fusion and to control particle size. Silver particles produced by a liquid-phase reduction method (wet reduction method) using a reducing agent have their surfaces coated with a surface treatment agent (lubricant). Therefore, silver particles produced by the reduction method can also be said to be silver particles surface-treated with a surface treatment agent. 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 aliphatic nitrile compounds such as oleanitrile (melting point: -1°C). The surface treatment agent may have a low melting point (for example, a melting point of 100°C or less) and high solubility in organic solvents.

[0024] The shape of component (A) is not particularly limited and may be, for example, flake-like, resin-like, spherical, etc. When component (A) is spherical, the surface roughness (Ra) of the film adhesive tends to be improved.

[0025] Component (A) may be metal particles (preferably conductive particles, more preferably silver particles) having an average particle size of 0.01 to 10 μm. When the average particle size of the metal particles is 0.01 μm or more, it tends to have the following effects: it can prevent an increase in viscosity when the adhesive varnish is produced; it can contain the desired amount of metal particles in the film adhesive; it can ensure the wettability of the film adhesive to the adherend, thereby exhibiting better adhesion. When the average particle size of the metal particles is 10 μm or less, it tends to have better film formability and further improve the heat dissipation properties due to the addition of metal particles. Furthermore, when the average particle size of the metal particles is 10 μm or less, it tends to be possible to further reduce the thickness of the film adhesive, further enabling the semiconductor chips to be stacked at a high density. In addition, it tends to be possible to prevent cracks in the semiconductor chips due to metal particles protruding from the film adhesive. The average particle size of the metal particles as component (A) may be 0.1 μm or more, 0.3 μm or more, or 0.5 μm or more, and may be 8.0 μm or less, 7.0 μm or less, 6.0 μm or less, 5.0 μm or less, 4.0 μm or less, or 3.0 μm or less.

[0026] In this specification, the average particle size of the metal particles as component (A) refers to the particle size (laser 50% particle size (D50)) when the ratio (volume fraction) of the total volume of the metal particles to the total volume of the metal particles is 50%. The average particle size (D50) can be determined by measuring a suspension of metal particles in water by a laser scattering method using a laser scattering particle size measuring device (e.g., Microtrac).

[0027] According to studies by the present inventors, it was found that when a film-like adhesive contains component (A), the shear viscosity and storage modulus of the film-like adhesive at 110°C are highly correlated with the quality of its step-filling ability. A film-like adhesive that satisfies at least one of the following conditions (i) and (ii) can be used to manufacture semiconductor devices with excellent heat dissipation properties and also has excellent step-filling properties. The film-like adhesive may satisfy both conditions (i) and (ii). Condition (i): The shear viscosity at 110°C is 35,000 Pa s or less. Condition (ii): The storage modulus at 265°C is 700 MPa or less.

[0028] The shear viscosity of the film-like adhesive at 110°C may be, for example, 35,000 Pa·s or less, 28,000 Pa·s or less, 26,000 Pa·s or less, 25,000 Pa·s or less, 24,000 Pa·s or less, 22,000 Pa·s or less, 20,000 Pa·s or less, 18,000 Pa·s or less, or 15,000 Pa·s or less. The lower limit of the shear viscosity of the film-like adhesive at 110°C is not particularly limited, but may be, for example, 3,000 Pa·s or more, 5,000 Pa·s or more, 6,000 Pa·s or more, or 7,000 Pa·s or more.

[0029] The shear viscosity at 110°C refers to a value measured by the following method. First, a film adhesive is cut to a predetermined size to prepare multiple film pieces. Next, these film pieces are laminated using a rubber roll on a hot plate at 70°C to prepare a laminate with a thickness of 300 μm. Next, this laminate is punched out with a φ10 mm punch to obtain a sample. The shear viscosity of this sample is measured under the following conditions using a rotational viscoelasticity measuring device (manufactured by TA Instruments Japan, product name: ARES-RDA). The shear viscosity value at a temperature of 110°C is defined as the shear viscosity at 110°C. Note that when the gap is set, the gap is adjusted so that the load applied to the sample is 10 g. (Measurement conditions) Disc plate: aluminum, 8 mmφ Measurement frequency: 1 Hz Heating rate: 5°C / min Strain: 5% Measurement temperature: 35 to 180°C Initial load: 10 g

[0030] The storage modulus of the film-like adhesive at 35°C and 265°C is 700 MPa or less, and may be 650 MPa or less, 600 MPa or less, 500 MPa or less, 450 MPa or less, or 400 MPa or less. The lower limit of the storage modulus of the film-like adhesive at 110°C (is not particularly limited), but may be, for example, 250 MPa or more, 300 MPa or more, or 350 MPa or more.

[0031] The storage modulus at 110°C refers to a value measured by the following method. First, the film adhesive is cut to a predetermined size to prepare multiple film pieces. Next, 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, this laminate is heated at 110°C for 1 hour, and then heated at 170°C for 3 hours to thermally cure. The cured product thus obtained is cut into a 4 mm x 30 mm piece to obtain a sample. The storage modulus of this sample is measured under the following conditions using a rotational viscoelasticity measuring device (for example, manufactured by TA Instruments Japan Co., Ltd., product name: ARES-RDA). The values ​​at temperatures of 35°C and 110°C are taken as the storage modulus at 35°C and 110°C, respectively. (Measurement conditions) Fundamental frequency: 10 Hz Measurement mode: strain dependency Heating rate: 3°C / min Measurement temperature: 30 to 270°C

[0032] The shear viscosity value of the film adhesive at 110°C can be reduced, for example, by the following methods: - Reducing the content of component (A) (increasing the content of components other than component (A)); - Increasing the ratio of the total amount of components (B) and (C) to the total amount of components (A), (B), (C), and (D); - Using component (B) or (C) with a softening point of 90°C or lower; - Using component (D) with a small molecular weight.

[0033] The content of component (A), based on the total mass of the film-like adhesive, may be 80.0 mass% or more, or may be 81.0 mass% or more, 82.0 mass% or more, or 83.0 mass% or more. When the content of component (A) is 80.0 mass% or more, the thermal conductivity of the film-like adhesive is improved, and the heat dissipation properties of the semiconductor device tend to be further improved. The content of component (A), based on the total mass of the film-like adhesive, may be, for example, 85.0 mass% or less, 84.5 mass% or less, or 84.0 mass% or less. When the content of component (A) is 85.0 mass% or less, other components can be more sufficiently contained in the film-like adhesive. This makes it easier to adjust the shear viscosity and storage modulus of the film-like adhesive at 110°C within the specified range, and the film-like adhesive tends to have better step-filling properties.

[0034] The content of component (A) may be 26.0 vol% or more, based on the total mass of the film-like adhesive, and may be 27.0 vol% or more, 28.0 vol% or more, 29.0 vol% or more, 30.0 vol% or more, 31.0 vol% or more, or 32.0 vol% or more. When the content of component (A) is 26.0 vol% or more, based on the total mass of the film-like adhesive, the thermal conductivity of the film-like adhesive tends to be improved, and the heat dissipation properties of the semiconductor device tend to be further improved. The content of component (A) may be, for example, 38.0 vol% or less, 37.0 vol% or less, 36.5 vol% or less, or 36.0 vol% or less, based on the total mass of the film-like adhesive. When the content of component (A) is 38.0 vol% or less, based on the total mass of the film-like adhesive, other components can be more sufficiently contained in the film-like adhesive. This makes it easier to adjust the shear viscosity at 110°C and storage modulus at 265°C of the film adhesive to fall within a predetermined range, and the film adhesive tends to have better step-filling properties.

[0035] The content (vol %) of the component (A) can be determined by, for example, multiplying the density of the film adhesive by x (g / cm ３ ), the density of component (A) is y (g / cm ３), where z (mass%) is the mass proportion of component (A) in the film-like adhesive. The mass proportion of component (A) in the film-like adhesive can be determined by thermogravimetric analysis using, for example, a thermogravimetric differential thermal analyzer (TG-DTA). The density of the film-like adhesive and component (A) can be determined by measuring the mass and specific gravity using a hydrometer. Content (volume %) of 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.

[0036] Component (B): Thermosetting Resin Component (B) is a component that has the property of forming three-dimensional bonds between molecules and curing when heated or the like, and is a component that exhibits adhesive properties after curing. Component (B) may be an epoxy resin. Any epoxy resin may be used without particular limitation as long as it has an epoxy group in the molecule. The epoxy resin may have two or more epoxy groups in the molecule.

[0037] 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, and diglycidyl ether compounds of polycyclic aromatics such as anthracene.

[0038] The epoxy resin may contain an epoxy resin having a softening point of 90° C. or lower. By containing an epoxy resin having a softening point of 90° C. or lower, the epoxy resin is sufficiently liquefied at 110° C., which tends to make it easier to adjust the shear viscosity of the film adhesive at 110° C. to within a predetermined range.

[0039] In this specification, the softening point refers to a value measured by the ring and ball method in accordance with JIS K7234.

[0040] The epoxy resin includes an epoxy resin that is liquid at 25°C (hereinafter sometimes referred to as a "first epoxy resin") and an epoxy resin that is solid at 25°C (hereinafter sometimes referred to as a "second epoxy resin"). The content of the first epoxy resin and the second epoxy resin in the epoxy resin is, for example, 90% by mass or more, and may be 95% by mass or more. The epoxy resin may be composed only of the first epoxy resin and the second epoxy resin.

[0041] When part of the epoxy resin is the first epoxy resin, the surface roughness (Ra) of the film-like adhesive tends to be improved. When the content of the second epoxy resin is taken as 1 part by mass, the content of the first epoxy resin may be 1.5 or more, or 1.6 or more, and may be 2.0 or less, 1.9 or less, or 1.8 or less. By adjusting the content in this range, the adhesion of the film-like adhesive is improved, and as a result, peeling of the cover film can be highly suppressed. Commercially available first epoxy resins include, for example, EXA-830CRP (trade name, manufactured by DIC Corporation) and YDF-8170C (trade name, Nippon Steel Chemical & Material Co., Ltd.).

[0042] 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 within this range, the fluidity of the adhesive varnish when forming the film adhesive tends to be easily ensured while maintaining the bulk strength of the film adhesive.

[0043] The content of component (B) may be 1.0 mass% or more, 3.0 mass% or more, 5.0 mass% or more, or 7.0 mass% or more, based on the total mass of the film-like adhesive, and may be 15.0 mass% or less, 14.0 mass% or less, 13.0 mass% or less, 12.0 mass% or less, or 11.0 mass% or less.

[0044] The equivalent ratio of the epoxy resin to the phenolic resin is not particularly limited, but may be 1.2 or more, or 1.3 or more, and may be 1.5 or less.

[0045] Component (C): Curing Agent Component (C) is a component that acts as a curing agent for component (B), specifically an epoxy resin curing agent. Examples of component (C) include phenolic resins (phenolic curing agents), acid anhydride curing agents, amine curing agents, imidazole curing agents, phosphine curing agents, azo compounds, and organic peroxides. When component (B) is an epoxy resin, component (C) may be a phenolic resin from the viewpoints of handleability, storage stability, and curability.

[0046] Any phenolic resin having a phenolic hydroxyl group in the molecule can be used without particular limitation. Examples of the phenolic resin 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.

[0047] The phenolic resin may contain a phenolic resin having a softening point of 90° C. or lower. By containing a phenolic resin having a softening point of 90° C. or lower, the phenolic resin is sufficiently liquefied at 110° C., which tends to make it easier to adjust the shear viscosity and storage modulus of the film adhesive at 110° C. to within predetermined ranges.

[0048] 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-like adhesive tends to be further improved, and when it is 300 g / eq or less, it becomes possible to prevent problems due to the generation of foaming, outgassing, etc.

[0049] From the viewpoint of curability, the ratio of the epoxy equivalent of the epoxy resin (B) to the hydroxyl equivalent of the phenolic resin (C) (epoxy equivalent of the epoxy resin (B) / hydroxyl equivalent of the phenolic resin (C)) 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.

[0050] The content of component (C) may be 1.0 mass% or more, 3.0 mass% or more, 4.0 mass% or more, or 5.0 mass% or more, based on the total mass of the film-like adhesive, and may be 15.0 mass% or less, 12.0 mass% or less, 10.0 mass% or less, or 9.0 mass% or less.

[0051] The total content of components (B) and (C) may be 13.0% by mass or more, based on the total mass of the film-like adhesive. When the total content of components (B) and (C) is 13.0% by mass or more, it becomes easier to adjust the shear viscosity and storage modulus of the film-like adhesive at 110°C within a predetermined range, and the film-like adhesive tends to have better step-filling properties. The total content of components (B) and (C) may be 13.2% by mass or more, 13.5% by mass or more, 14.0% by mass or more, 14.5% by mass or more, 15.0% by mass or more, or 15.5% by mass or more, based on the total mass of the film-like adhesive. The total content of the (B) component and the (C) component may be 30.0 mass% or less, 25.0 mass% or less, 23.0 mass% or less, 22.0 mass% or less, 21.0 mass% or less, 20.0 mass% or less, or 18.0 mass% or less, based on the total mass of the film-like adhesive.

[0052] Component (D): Elastomer Examples of component (D) include polyimide resins, acrylic resins, urethane resins, polyphenylene ether resins, polyetherimide resins, phenoxy resins, and modified polyphenylene ether resins. Component (D) may be any of these resins having crosslinkable functional groups, or may be an acrylic resin having crosslinkable functional groups. Here, the term "acrylic resin" refers to a (meth)acrylic (co)polymer containing structural units derived from (meth)acrylate ((meth)acrylic acid ester). The acrylic resin may be a (meth)acrylic (co)polymer containing structural units derived from (meth)acrylate having crosslinkable functional groups such as epoxy groups, alcoholic or phenolic hydroxyl groups, and carboxy groups. The acrylic resin may also be an acrylic rubber, such as a copolymer of (meth)acrylate and acrylonitrile. These elastomers may be used alone or in combination of two or more.

[0053] Examples of commercially available acrylic resins include SG-P3 solvent-modified product, SG-70L, SG-708-6, WS-023 EK30, SG-280 EK23, HTR-860P-3, HTR-860P-3CSP, and HTR-860P-3CSP-3DB (all manufactured by Nagase ChemteX Corporation).

[0054] The glass transition temperature (Tg) of the elastomer as component (D) may be -50 to 50°C or -30 to 20°C. When the Tg is -50°C or higher, the tackiness of the film-like adhesive tends to be reduced, thereby further improving handleability. When the Tg is 50°C or lower, the fluidity of the adhesive varnish when forming the film-like adhesive tends to be more sufficiently ensured. Here, the Tg of the elastomer as component (D) refers to the value measured using a DSC (differential scanning calorimeter) (for example, Thermo Plus 2, product name, manufactured by Rigaku Corporation).

[0055] The weight average molecular weight (Mw) of the elastomer as component (D) may be 50,000 to 1.6 million, 100,000 to 1.4 million, or 300,000 to 1.2 million. When the glass transition temperature of the elastomer as component (D) is 50,000 or higher, the film-forming properties tend to be better. When the weight average molecular weight of component (D) is 1.6 million or less, the fluidity of the adhesive varnish when forming a film-like adhesive tends to be better. Here, the Mw of the elastomer as component (D) means a value measured by gel permeation chromatography (GPC) and converted using a calibration curve based on standard polystyrene.

[0056] The measurement device and conditions for measuring the Mw of the elastomer as component (D) are, for example, as follows: Pump: L-6000 (manufactured by Hitachi, Ltd.) Column: Gelpack GL-R440 (manufactured by Hitachi Chemical Co., Ltd.), Gelpack GL-R450 (manufactured by Hitachi Chemical Co., Ltd.), and Gelpack GL-R400M (manufactured by Hitachi Chemical Co., Ltd.) (each 10.7 mm (diameter) × 300 mm) connected in this order Eluent: tetrahydrofuran (hereinafter referred to as "THF") Sample: solution prepared by dissolving 120 mg of sample in 5 mL of THF Flow rate: 1.75 mL / min

[0057] The content of component (D) may be 15.0% by mass or less, 12.0% by mass or less, 10.0% by mass or less, or 9.0% by mass or less, based on the total mass of the film-like adhesive. If the content of component (D) is 15.0% by mass or less, based on the total mass of the film-like adhesive, it is possible to prevent the viscosity from becoming too high, which would result in a decrease in the ability to fill gaps. From the viewpoint of film processability, the lower limit of the content of component (D) may be 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, or 2.8% by mass or more, based on the total mass of the film-like adhesive.

[0058] Component (E): Coupling Agent Component (E) may be a silane coupling agent. Examples of the silane coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane.

[0059] Component (F): Curing Accelerator Examples of the component (F) include imidazoles and derivatives thereof, organic phosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts, etc. Among these, from the viewpoint of reactivity, the component (F) may be imidazoles and derivatives thereof.

[0060] Examples of imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, etc. These may be used alone or in combination of two or more.

[0061] The film adhesive may further contain other components, such as pigments, ion scavengers, and antioxidants.

[0062] The total content of the component (E), the component (F), and other components may be 0.005 to 10% by mass based on the total mass of the film-like adhesive.

[0063] [Method for Producing Film状 Adhesive] The method for producing the film状 adhesive 10A shown in Fig. 1 is not particularly limited. For example, a raw varnish containing the component (A) and an organic solvent is mixed to prepare an adhesive varnish containing the component (A), the organic solvent, the component (B), and the component (C) (mixing step), and a film状 adhesive is formed using the adhesive varnish (forming step). It can be obtained by a production method comprising these steps. The adhesive varnish may further contain the component (D), the component (E), the component (F), and other components, etc., as necessary.

[0064] (Mixing Step) The mixing step is a step of mixing a raw varnish containing the component (A) and an organic solvent to prepare an adhesive varnish containing the component (A), the organic solvent, the component (B), and the component (C).

[0065] 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, γ-butyrolactone, butyl carbitol acetate, and ethyl carbitol acetate; carbonates such as ethylene carbonate and propylene carbonate; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; and alcohols such as butyl carbitol and ethyl carbitol. These organic solvents may be used alone or in combination of two or more. Of these, the organic solvent may be N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, butyl carbitol, ethyl carbitol, butyl carbitol acetate, ethyl carbitol acetate, or cyclohexanone, from the viewpoint of the solubility and boiling point of the surface treatment agent. The solid component concentration in the raw varnish may be 10 to 80 mass % based on the total mass of the raw varnish.

[0066] 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.

[0067] 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.

[0068] The mixing temperature in the mixing step is not particularly limited, but may be 50°C or higher. The mixing temperature in the mixing step may be increased, if necessary, using heating equipment or the like. The inventors have found that, for example, when silver particles (preferably silver particles produced by a reduction method) are used, if the mixing temperature in the mixing step is 50°C or higher, the resulting film-like adhesive may contain a sintered body of silver particles in the C-stage state. This phenomenon is more pronounced when silver particles produced by a reduction method are used as component (A). The reason for this phenomenon is not entirely clear, but the inventors believe it to be as follows. Silver particles (produced by a liquid-phase (wet) reduction method using a reducing agent) used as component (A) are usually coated on the surface with a surface treatment agent (lubricant). It is presumed that if the mixing temperature in the mixing step is 50°C or higher, the surface treatment agent coating the silver particles dissociates, easily exposing the silver surface (in a reduced state). Furthermore, since such silver particles with exposed silver surfaces are likely to come into direct contact with each other, it is presumed that when the film-like adhesive is heated under conditions that cure the silver particles, the silver particles sinter together and tend to form a sintered body of silver particles. This is thought to result in the film-like adhesive containing a sintered body of silver particles in a C-stage state. Silver particles produced by the atomization method are covered on their surfaces with a silver oxide film due to the characteristics of their manufacturing method. The inventors have confirmed that when silver particles produced by the atomization method are used, even if the mixing temperature in the mixing step is 50°C or higher, the resulting film-like adhesive is unlikely to contain a sintered body of silver particles in a C-stage state. The mixing temperature in the mixing step 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 in the mixing step may be, for example, 120°C or lower, 100°C or lower, or 80°C or lower. The mixing time in the mixing step may be, for example, 1 minute or more, 5 minutes or more, or 10 minutes or more, and may be 60 minutes or less, 40 minutes or less, or 20 minutes or less.

[0069] The (B), (C), (D), (E), (F), or other components can be added to the adhesive varnish at any stage, depending on the properties of each component. These components may be added to the raw varnish before the mixing step, or may be added to the adhesive varnish after the mixing step. The (B) and (C) components are preferably added to the raw varnish before the mixing step. The (D) component may be added to the raw varnish before the mixing step, or may be added to the adhesive varnish after the mixing step. The (E) and (F) components are preferably added to the adhesive varnish after the mixing step. When the (E) and (F) components are added to the adhesive varnish after the mixing step, they may be mixed at a temperature of less than 50°C (e.g., room temperature (25°C)) after addition. In this case, the mixing conditions may be at room temperature (25°C) for 0.1 to 48 hours.

[0070] In one embodiment, the mixing step may be a step of mixing a raw material varnish containing the (A) component, the (B) component, the (C) component, the (D) component, and an organic solvent at a mixing temperature of preferably 50°C or higher to prepare an adhesive varnish containing the (A) component, the (B) component, the (C) component, the (D) component, and an organic solvent.

[0071] In this manner, an adhesive varnish containing component (A), organic solvent, component (B), and component (C) can be prepared. After preparation, air bubbles in the adhesive varnish may be removed by vacuum degassing or the like.

[0072] The solid component concentration in the adhesive varnish may be 10 to 80% by weight based on the total weight of the adhesive varnish.

[0073] (Forming Step) The forming step is a step of forming a film-like adhesive using an adhesive varnish. Examples of a method for forming a film-like adhesive include a method of applying the adhesive varnish to a support film.

[0074] The adhesive varnish can be applied to the support film by any known method, such as knife coating, roll coating, spray coating, gravure coating, bar coating, or curtain coating.

[0075] After the adhesive varnish is applied to the support film, the organic solvent may be dried by heating, if necessary. The conditions for the drying by heating are not particularly limited as long as the organic solvent used is sufficiently volatilized, but for example, the drying by heating temperature may be 50 to 200°C, and the drying by heating time may be 0.1 to 30 minutes. The drying by heating may be carried out stepwise at different temperatures or for different times.

[0076] In this manner, the film adhesive 10 A can be obtained. The thickness of the film adhesive 10 A can be adjusted appropriately depending on the application, but may be, for example, 3 μm or more, 5 μm or more, or 10 μm or more, and may be 200 μm or less, 100 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less.

[0077] In the C-stage state, the thermal conductivity (25°C ± 1°C) of the film-like adhesive 10A may be 1.5 W / (m·K) or more. A thermal conductivity of 1.5 W / (m·K) or more tends to improve the heat dissipation of the semiconductor device. The thermal conductivity may be 2.0 W / (m·K) or more, 2.5 W / (m·K) or more, 3.0 W / (m·K) or more, 3.5 W / (m·K) or more, 4.0 W / (m·K) or more, 4.5 W / (m·K) or more, or 5.0 W / (m·K) or more. The upper limit of the thermal conductivity (25°C ± 1°C) of the film-like adhesive 10A in the C-stage state is not particularly limited, but may be 30 W / (m·K) or less. In this specification, thermal conductivity refers to the value calculated using the method described in the examples. The conditions for curing the film adhesive 10A to the C-stage state may be, for example, a heating temperature of 170° C. and a heating time of 3 hours.

[0078] [Dicing and die bonding integrated film and manufacturing method thereof] 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 comprises, in this order, a base layer 40, a first adhesive layer 30, and a second adhesive layer 10 made of a film-like adhesive 10A. The dicing and die bonding integrated film 100 can also be said to comprise a dicing tape 50 comprising the base layer 40 and the first adhesive layer 30 provided on the base layer 40, and a second adhesive layer 10 provided on the first 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 comprise a support film 20 on the surface of the second adhesive layer 10 opposite to the first adhesive layer 30. A cover film may be provided instead of the support film 20. As the cover film, a film of the same material and thickness as the support film 20 can be used.

[0079] 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. 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.

[0080] The first 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 conventionally known in the field of dicing tapes can be used. The first adhesive layer 30 may be a first adhesive layer made of a pressure-sensitive adhesive or a first adhesive layer made of an ultraviolet-curable adhesive. If the first adhesive layer is a first adhesive layer made of an ultraviolet-curable adhesive, the adhesiveness of the first adhesive layer can be reduced by irradiating it with ultraviolet light.

[0081] The thickness of the dicing tape 50 (base layer 40 and first adhesive layer 30) may be 60 to 150 μm or 70 to 130 μm from the viewpoints of economy and film handling.

[0082] 2 can be obtained by a manufacturing method including the steps of preparing a dicing tape 50 including a film adhesive 10A, a base layer 40, and a first adhesive layer 30 provided on the base layer 40, and bonding the film adhesive 10A to the first adhesive layer 30 of the dicing tape 50. A known method can be used as the method for bonding the film adhesive 10A to the first adhesive layer 30 of the dicing tape 50.

[0083] 3(a) to 3(f) are cross-sectional views schematically illustrating a series of steps for manufacturing a semiconductor device. The method for manufacturing a semiconductor device includes a step of attaching a semiconductor wafer W to the second adhesive layer 10 of the dicing and die bonding integrated film 100 (wafer lamination step, see FIGS. 3(a) and 3(b)), a step of dicing the semiconductor wafer W with the second adhesive layer 10 attached to produce a plurality of individual semiconductor chips 60 with adhesive pieces attached (dicing step, see FIG. 3(c)), and a step of bonding the semiconductor chips 60 with adhesive pieces attached to a support member 80 via adhesive pieces 10a (semiconductor chip bonding step, see FIG. 3(f)). The method for manufacturing a semiconductor device may further include, between the dicing process and the semiconductor chip bonding process, a process of irradiating ultraviolet light onto the first adhesive layer 30 (through the base layer 40) (ultraviolet light irradiation process, see Figure 3(d)), a process of picking up the semiconductor chip 60 with adhesive pieces from the first adhesive layer 30a (pick-up process, see Figure 3(e)), and a process of thermally curing the adhesive pieces 10a on the semiconductor chip 60 with adhesive pieces bonded to the support member 80 (thermal curing process), as necessary.

[0084] (Wafer Lamination Process) In this process, first, the dicing and die bonding integrated film 100 is placed in a predetermined device. Next, the surface Ws of the semiconductor wafer W is attached to the second 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 surface Ws.

[0085] Examples of the semiconductor wafer W include single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

[0086] (Dicing Process) In this process, the semiconductor wafer W and the second adhesive layer 10 are diced into individual pieces (see FIG. 3(c)). The semiconductor chip 60 with adhesive pieces has a semiconductor chip Wa and an adhesive piece 10a. The semiconductor chip Wa is obtained by dividing the semiconductor wafer W, and the adhesive piece 10a is obtained by dividing the second adhesive layer 10. Also, a part of the first adhesive layer 30, or the entire first adhesive layer 30 and a part of the base layer 40 may be cut. The first adhesive layer 30a shown in FIG. 3(c) is obtained by dividing the first adhesive layer 30. In this way, the dicing and die bonding integrated film 100 also functions as a dicing sheet.

[0087] (Ultraviolet Light Irradiation Step) When the first adhesive layer 30 is an ultraviolet-curable first adhesive layer, the method for manufacturing a semiconductor device may include an ultraviolet light irradiation step. In this step, ultraviolet light is irradiated onto the first adhesive layer 30 (through the base layer 40) (see FIG. 3(d)). In the ultraviolet light irradiation, 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

[0088] (Pick-up process) In this process, the base material layer 40 is expanded to separate the individual semiconductor chips 60 with adhesive pieces from each other, while the semiconductor chips 60 with adhesive pieces pushed up from the base material layer 40 side by the needles 72 are sucked with a suction collet 74 and picked up from the first adhesive layer 30a (see FIG. 3(e)). The first adhesive layer 30a may remain on the base material layer 40 after the semiconductor chips 60 with adhesive pieces are picked up. In this process, it is not necessarily necessary to expand the base material layer 40, but expanding the base material layer 40 can further improve the pick-up properties.

[0089] 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 adhesive piece attached may be picked up by a method other than the method using the suction collet 74.

[0090] (Semiconductor Chip Bonding Process) In this process, the picked-up semiconductor chip 60 with adhesive piece is bonded to the support member 80 via the adhesive piece 10a by thermocompression bonding (see FIG. 3(f)). A plurality of semiconductor chips 60 with adhesive piece may be bonded to the support member 80.

[0091] 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 50 N. The heating time in the thermocompression bonding may be, for example, 0.5 to 20 seconds.

[0092] (Thermal Curing Process) In this process, the adhesive piece 10a of the semiconductor chip 60 with adhesive piece bonded to the support member 80 is thermally cured. Thermal curing of the adhesive piece 10a or the cured adhesive piece 10ac bonding the semiconductor chip Wa to the support member 80 enables a stronger adhesive fixation. Furthermore, when component (A) is silver particles (preferably silver particles produced by a reduction method), thermal curing of the adhesive piece 10a or the cured adhesive piece 10ac tends to make it easier to obtain a sintered body of the silver particles. When performing thermal curing, pressure may be applied simultaneously to harden the adhesive piece 10a. The heating temperature in this process can be appropriately changed depending on the constituent components of the adhesive piece 10a. The heating temperature may be, for example, 60 to 200°C, 80 to 190°C, or 100 to 180°C. The heating time may be, for example, 1 to 120 minutes, 5 to 100 minutes, 10 to 80 minutes, or 15 to 60 minutes. The temperature or pressure may be changed stepwise.

[0093] The adhesive piece 10a can be cured through a semiconductor chip bonding process or a thermal curing process to become a cured adhesive piece 10ac. When the component (A) is silver particles (preferably silver particles produced by a reduction method), the cured adhesive piece 10ac can contain a sintered body of silver particles. Therefore, the resulting semiconductor device can have excellent heat dissipation properties.

[0094] 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 element 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 several seconds to several minutes. Wire bonding may be performed by combining ultrasonic vibration energy and compression energy due to applied pressure in a heated state within the above temperature range.

[0095] The method for manufacturing a semiconductor device may optionally include a step of encapsulating the semiconductor element with an encapsulant (encapsulation step). This step is performed to protect the semiconductor element 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 support member and residue are embedded by the heat and pressure during encapsulation, preventing peeling due to air bubbles at the adhesive interface.

[0096] 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 piece is not thermally cured in the encapsulating step, in this step, the adhesive piece can be thermally cured along 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.

[0097] The method for manufacturing a semiconductor device may optionally include a step of heating the semiconductor element with adhesive 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.

[0098] [Semiconductor Device] 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 film-like adhesive (cured adhesive piece 10ac). 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).

[0099] The semiconductor chip Wa (semiconductor element) 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 substrate such as a glass nonwoven fabric with a plastic such as polyimide resin or epoxy resin; and ceramics such as alumina.

[0100] The semiconductor device 200 has excellent heat dissipation properties because it includes the cured film adhesive as the adhesive member.

[0101] The present disclosure will be specifically described below based on examples, but the present disclosure is not limited to these examples.

[0102] (Examples 1 to 4 and Comparative Examples 1 to 3) <Preparation of Adhesive Varnish> A raw varnish was prepared by adding cyclohexanone as an organic solvent to components (A), (B), (C), and (D) according to the symbols and compositional ratios (unit: parts by mass) shown in Tables 1 and 2. The raw varnish was stirred at 4,000 rpm for 20 minutes at a mixing temperature of 70°C using a Homodisper (T.K. HOMO MIXER MARK II, manufactured by Tajima Chemical Machinery Co., Ltd.) to obtain an adhesive varnish. The adhesive varnish was then allowed to cool to 20 to 30°C, after which components (E) and (F) were added to the adhesive varnish and stirred overnight at 250 rpm using a Three-One motor. In this way, adhesive varnishes having a total content of components (A), (B), (C), and (D) of 61% by mass were prepared for Examples 1 to 4 and Comparative Examples 1 to 3.

[0103] The symbols of the components in Tables 1 and 2 have the following meanings.

[0104] Component (A): Metal particles A1: Silver particles AG-3-1F (trade name, manufactured by DOWA Electronics Co., Ltd., shape: spherical, average particle size (laser 50% particle size (D ５０ )): 1.5 μm)

[0105] Component (B): Thermosetting Resin B1: EXA-830CRP (trade name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 159 g / eq, liquid at 25°C) B2: N-500P-10 (trade name, manufactured by DIC Corporation, cresol novolac type epoxy resin, epoxy equivalent: 204 g / eq, softening point: 84°C)

[0106] Component (C): Curing agent C1: MEH-7800M (trade name, manufactured by Meiwa Chemical Industry Co., Ltd., phenylaralkyl phenolic resin, hydroxyl group equivalent: 174 g / eq, softening point: 80°C)

[0107] Component (D): Elastomer D1: SG-P3 solvent-modified product (trade name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight-average molecular weight: 800,000, Tg: 15°C)

[0108] Component (E): Coupling agent E1: Z-6119 (trade name, Toray Dow Corning, ureidopropyltrialkoxysilane)

[0109] Component (F): Curing accelerator F1: 1B2MZ (trade name, manufactured by Shikoku Chemicals Corporation, 1-benzyl-2-methyl-1H-imidazole)

[0110] <Calculation of volume %> The content (vol %) of component (A) is calculated by multiplying the density of the film adhesive by x (g / cm ３ ), the density of component (A) is y (g / cm ３ ), where z (mass%) is the mass proportion of component (A) in the film adhesive. The mass proportion of component (A) in the film adhesive was determined by thermogravimetric analysis using a thermogravimetric differential thermal analyzer (TG-DTA). The densities of the film adhesive and component (A) were determined by measuring the mass and specific gravity using a hydrometer. Content (volume %) of 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.

[0111] <Laminate Preparation> Film-like adhesives were prepared using the adhesive varnishes of Examples 1 to 4 and Comparative Examples 1 to 3. Each adhesive varnish was vacuum degassed, and then coated onto a release-treated polyethylene terephthalate (PET) film (thickness: 38 μm) that served as a support film. The coated adhesive varnish was dried by heating in two stages: at 90°C for 5 minutes and then at 130°C for 5 minutes. A polyethylene (PE) film (thickness: ) was then laminated onto the resulting film-like adhesive, yielding a laminate comprising a 25 μm-thick film-like adhesive of Examples 1 to 4 and Comparative Examples 1 to 3 in a B-stage state on a PET film, and a PE film on top of that. The equivalent ratio of epoxy resin to phenolic resin in the film-like adhesives of Examples 1 to 4 and Comparative Examples 1 to 3 was 1.25.

[0112] <Measurement of Shear Viscosity of Film Adhesive at 110°C> Each of the film adhesives (thickness: 25 μm) of Examples 1 to 4 and Comparative Examples 1 to 3 was cut to a predetermined size to prepare 12 film pieces. Next, the 12 film pieces were laminated using a rubber roll on a hot plate at 70°C to prepare a laminate with a thickness of 300 μm. Next, the laminate was punched out with a φ10 mm punch to prepare a sample, and the shear viscosity of the prepared sample at 110°C was measured using a rotational viscoelasticity measuring device (manufactured by TA Instruments Japan, Inc., product name: ARES-RDA) under the following measurement conditions. Note that when the gap was set, the gap was adjusted so that the load on the sample was 10 g. The results are shown in Tables 1 and 2. (Measurement conditions) Disc plate: Aluminum, 8 mm diameter Measurement frequency: 1 Hz Heating rate: 5°C / min Distortion: 5% Measurement temperature: 35 to 180°C Initial load: 10 g

[0113] <Evaluation of Storage Modulus> (Preparation of Evaluation Samples) Each of the film-like adhesives of Examples 1 to 4 and Comparative Examples 1 to 3 was laminated with a rubber roll to prepare a laminate film with a thickness of 200 μm or more. The laminate film was then heated in a constant temperature dryer at 110°C for 1 hour and then at 170°C for 3 hours. The heat-cured laminate was cut into a 4 mm x 30 mm piece to obtain a sample for storage modulus measurement. (Evaluation of Storage Modulus of Evaluation Samples) The storage modulus of the obtained sample was measured at 35°C and 110°C using a dynamic viscoelasticity evaluation device (manufactured by UBM Inc., product name: Rheogel-E4000) under the following measurement conditions. The results are shown in Tables 1 and 2. (Measurement Conditions) Fundamental frequency: 10 Hz Measurement mode: Strain dependency Heating rate: 3°C / min Measurement temperature: 30 to 270°C

[0114] <Evaluation of Die Shear Strength> (Preparation of Evaluation Samples) The semiconductor wafer in the obtained integrated film was diced into individual pieces of 5 mm x 5 mm, and then a lead frame (LF810 tab sage) was prepared. The lead frame was heated to a stage temperature of 70 ° C. and pre-pressed for 3 seconds. Then, the stage temperature was heated to 120 ° C., the pressing time was 5 seconds, and the pressing load was 0.01 MPa. The semiconductor chip with the adhesive piece was pressed onto the lead frame via the adhesive piece. The lead frame with the semiconductor chip pressed onto it was then heated at a temperature of 110 ° C. and a pressure of 0.7 MPa for 1 hour, and then at a temperature of 170 ° C. and a pressure of 0.7 MPa for 3 hours to thermally cure the adhesive piece, thereby obtaining an evaluation sample. (Evaluation of the Die Shear Strength of the Evaluation Sample) Using a die shear strength measuring device (manufactured by Daisy), the stage temperature was set to 265 ° C., and the heat-cured evaluation sample was left on the stage for 20 seconds, and then a destruction test was performed. The results are shown in Table 1.

[0115] <Evaluation of 90°C Peel Strength> DAF / PE side: After the forming process, the sheet was cut into a size of 20 mm x 100 mm while still attached to the cover film. Then, a test piece with double-sided tape attached was prepared, the PET was peeled off, and the DAF surface was attached to the double-sided tape. A 90°C peel test was performed using a 90°C peel tester (manufactured by Tester Sangyo Co., Ltd.) at room temperature (25°C) and a peeling speed of 50 mm / min. The results are shown in Table 1. DAF / PET side: The DAF with the PE peeled off was attached to the double-sided tape of the test piece with double-sided tape, using almost the same method as above, and the rest was the same as above.

[0116] <Evaluation of DAF / PE adhesion> Evaluation was carried out visually on samples after the molding process. The evaluation criteria were as follows. The results are shown in Table 1. A: Almost no peeling was observed. B: Some peeling was observed. C: Peeling occurred over a wide area.

[0117] <Measurement of Thermal Conductivity> (Preparation of Film for Measuring Thermal Conductivity) A laminated film having a thickness of 200 μm or more was prepared by bonding together multiple sheets of the film-like adhesive of each of Examples 1 to 4 and Comparative Examples 1 to 3 with a rubber roll. The laminated film was then cut into a 1 cm × 1 cm piece, and the cut laminated film was thermally cured in a constant temperature dryer at 110°C for 1 hour and then at 170°C for 3 hours to obtain a film for measuring thermal conductivity in a C-stage state.

[0118] (Calculation of Thermal Conductivity) The thermal conductivity λ of the thermal conductivity measurement film in the thickness direction was calculated using the following formula. The results are shown in Tables 1 and 2. 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.

[0119] (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: 35°C

[0120] (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: 35°C to 75°C

[0121] (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

[0122]

[0123]

[0124] In Tables 1 and 2, the "content of component (A) [mass %]" and "content of component (A) [volume %]" are both based on the total amount of the film-like adhesive (the total amount of components (A), (B), (C), (D), (E), and (F)). The film-like adhesives of Examples 1 to 4, in which the content of component (A) was 80.0 mass % or more and the value of B1 / A×100 was in the range of 4.0 to 5.5, had better thermal conductivity and better adhesion to the cover film than the film-like adhesives of Comparative Examples 1 to 3, which did not satisfy these conditions.

[0125] From the above, it was confirmed that the film adhesive of the present disclosure is capable of producing semiconductor devices with excellent heat dissipation properties and has excellent adhesion.

[0126] According to the present disclosure, a film-like adhesive that enables the production of a semiconductor device with excellent heat dissipation and has excellent adhesion is provided. Also, according to the present disclosure, a dicing and die bonding integrated film using such a film-like adhesive is provided. Furthermore, according to the present disclosure, a semiconductor device using such a film-like adhesive or dicing and die bonding integrated film and a manufacturing method thereof are provided.

[0127] 10...adhesive layer, 10A...film-like adhesive, 10a...adhesive piece, 10ac...cured adhesive piece, 12...adhesive member, 20...support film, 30, 30a...first adhesive layer, 40...base material layer, 50...dicing tape, 60...semiconductor chip with adhesive 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 film-like adhesive comprising metal particles, an epoxy resin, a phenolic resin and an elastomer, wherein the content of the metal particles is 80.0 mass% or more based on the mass of the film-like adhesive, the epoxy resin comprises a first epoxy resin that is liquid at 25°C and a second epoxy resin that is solid at 25°C, and when the content of the metal particles is 100 mass parts, the content of the first epoxy resin is 4.0 to 5.5 mass parts.

2. A film-like adhesive as described in claim 1, wherein the content of the first epoxy resin is 1.5 parts by mass or more when the content of the second epoxy resin is 1 part by mass.

3. The film-like adhesive according to claim 1, wherein the content of said metal particles is 26 to 38 volume % based on the volume of said film-like adhesive.

4. The film adhesive according to claim 1, wherein the metal particles are silver particles.

5. The film adhesive according to claim 1, wherein the equivalent ratio of said epoxy resin to said phenolic resin is 1.2 or more.

6. The film adhesive according to claim 1, having a thickness of 5 to 40 μm.

7. A film-like adhesive as described in claim 1, having a thermal conductivity of 7 W / (m·K) or more at 25°C ± 1°C after heat curing at 170°C for 3 hours.

8. A film-like adhesive as described in claim 1, wherein the content of the elastomer is 15.0 mass% or less based on the mass of the film-like adhesive.

9. A dicing and die bonding integrated film having a laminated structure including a base layer, a first adhesive layer, and a second adhesive layer in this order, the second adhesive layer being composed of a film-like adhesive according to any one of claims 1 to 8.

10. The dicing and die bonding integrated film according to claim 9, further comprising a cover film provided so as to cover the second adhesive layer.

11. 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 bonding the semiconductor chip to the support member, wherein the adhesive member is a cured product of a film-like adhesive described in any one of claims 1 to 8.

12. A method for manufacturing a semiconductor device, comprising the steps of: attaching the second adhesive layer of the dicing / die bonding integrated film described in claim 9 to a semiconductor wafer; obtaining a semiconductor chip with an adhesive piece composed of a semiconductor chip and an adhesive piece by singulating the laminate of the semiconductor wafer and the second adhesive layer; and adhering the semiconductor chip to a support member via the adhesive piece.

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