Film-shaped adhesive, dicing / die-bonding integrated film, and semiconductor device and production method therefor

Abstract

Disclosed is a film-shaped adhesive comprising thermally conductive particles, an epoxy resin, and one or more phenolic resins. In one embodiment, the phenolic resins include a phenolic resin having a hydroxyl equivalent of 185 g / eq or greater. The proportion of the phenolic resin having a hydroxyl equivalent of 185 g / eq or greater is 70 mass% or higher with respect to the total amount of the phenolic resins. In another embodiment, the phenolic resins include a phenolic resin having a biphenyl skeleton. The proportion of the phenolic resin having a biphenyl skeleton is 70 mass% or higher with respect to the total amount of the phenolic resins.

Description

Film-like adhesive, dicing and die bonding integrated film, semiconductor device and method for manufacturing the same.

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

[0002] Conventionally, semiconductor devices are manufactured through the following process. First, a semiconductor wafer is attached to a dicing adhesive sheet, and in this state, the semiconductor wafer is divided into individual semiconductor chips (dicing process). Subsequently, a pickup process, a crimping process, and a die bonding process are carried out. Patent Document 1 discloses an adhesive film (dicing / die bonding integrated film) that has the function of fixing the semiconductor wafer in the dicing process and the function of bonding the semiconductor chip to the substrate in the die bonding process. By dividing the semiconductor wafer and adhesive layer into individual chips in the dicing process, semiconductor chips with adhesive chips can be obtained.

[0003] In recent years, devices called power semiconductor devices, which control power and perform other functions, have become widespread. Power semiconductor devices tend to generate heat due to the supplied current, and therefore require excellent heat dissipation. Patent document 2 discloses a film-like adhesive that has higher heat dissipation after curing than before curing.

[0004] Japanese Patent Publication No. 2008-218571 Japanese Patent Publication No. 2016-103524

[0005] With the increasing performance of semiconductor devices, there is a strong demand for further improvements in heat dissipation, particularly in power semiconductor devices. One effective means of improving the heat dissipation of film-type adhesives is to incorporate thermally conductive particles into the film-type adhesive and increase the amount of these particles packed into the adhesive.

[0006] However, our own research has shown that when a film-like adhesive is highly filled with thermally conductive particles, if the film-like adhesive is stored for a long period of time in a relatively low temperature environment (e.g., room temperature range (20-40°C)) before curing (e.g., in the B-stage state), the storage modulus of the resulting cured product at high temperatures (e.g., 200°C) tends to decrease over time. On the other hand, even if the cured product is stored for a long period of time in a similar relatively low temperature environment, no substantial change in the storage modulus is observed. A decrease in the storage modulus at high temperatures after curing reduces the stress relaxation ability against loads such as temperature cycling, which can impair the long-term reliability of semiconductor devices by reducing the adhesive reliability between semiconductor chips and substrates.

[0007] Therefore, the main objective of this disclosure is to provide a film-like adhesive that, when highly filled with thermally conductive particles, can suppress the time-dependent decrease in storage modulus at high temperatures after curing, even when cured after being stored at relatively low temperatures for a long period of time before curing.

[0008] This disclosure provides a film-like adhesive as described in [1] to [8], a dicing-die bonding integrated film as described in [9], a semiconductor device as described in

[10] , and a method for manufacturing a semiconductor device as described in

[11] and

[12] . [1] A film-like adhesive containing thermally conductive particles, an epoxy resin, and a phenolic resin, wherein the phenolic resin contains a phenolic resin having a hydroxyl group equivalent of 185 g / eq or more, and the content of the phenolic resin having a hydroxyl group equivalent of 185 g / eq or more is 70% by mass or more based on the total amount of the phenolic resin. [2] A film-like adhesive containing thermally conductive particles, an epoxy resin, and a phenolic resin, wherein the phenolic resin contains a phenolic resin having a biphenyl skeleton, and the content of the phenolic resin having a biphenyl skeleton is 70% by mass or more based on the total amount of the phenolic resin. [3] The film-like adhesive as described in [1], wherein the phenolic resin having a hydroxyl group equivalent of 185 g / eq or more is a phenolic resin having a biphenyl skeleton. [4] The film-like adhesive according to any one of [1] to [3], wherein the content of the thermally conductive particles is 60% by mass or more based on the total amount of the film-like adhesive. [5] The film-like adhesive according to any one of [1] to [4], further containing an elastomer. [6] The film-like adhesive according to any one of [1] to [5], wherein the epoxy resin is a liquid epoxy resin that is liquid at 30°C. [7] The film-like adhesive according to any one of [1] to [6], wherein the thermally conductive particles are metal particles. [8] The film-like adhesive according to any one of [1] to [7], having a thickness of 150 μm or less. [9] A dicing-die bonding integrated film comprising, in this order, a base layer, an adhesive layer, and an adhesive layer made of the film-like adhesive according to any one of [1] to [8].

[10] A semiconductor device comprising: a semiconductor chip; a support member on which the semiconductor chip is mounted; and a cured product of a film-like adhesive according to any one of [1] to [8] provided between the semiconductor chip and the support member to bond the semiconductor chip and the support member.

[11] A method for manufacturing a semiconductor device, comprising the step of interposing a film-like adhesive described in any of [1] to [8] between a semiconductor chip and a support member to bond the semiconductor chip and the support member.

[12] A method for manufacturing a semiconductor device, comprising the steps of attaching the adhesive layer of a dicing-die bonding integrated film described in [9] to a semiconductor wafer; producing a plurality of individualized semiconductor chips with adhesive pieces by dicing the semiconductor wafer to which the adhesive layer has been attached; and bonding the semiconductor chips with adhesive pieces to a support member via the adhesive pieces.

[0009] This disclosure provides a film-like adhesive that, when highly packed with thermally conductive particles, can suppress the time-dependent decrease in storage modulus at high temperatures after curing, even when cured after being stored at relatively low temperatures for a long period before curing. This disclosure also provides a dicing-die bonding integrated film using such a film-like adhesive. Furthermore, this disclosure provides a semiconductor device and a method for manufacturing the same using such a film-like adhesive or a dicing-die bonding integrated film.

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

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

[0012] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers listed before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this specification, the upper or lower limit of one step in the numerical range may be replaced with the upper or lower limit of another step in the numerical range. Also, in numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. Furthermore, the upper and lower limits described individually can be combined in any way. Also, "A or B" means that either A or B is included, or both are included. Furthermore, unless otherwise specified, the materials exemplified below may be used individually or in combination of two or more. The content of each component in the composition means the total amount of multiple substances present in the composition if there are multiple substances corresponding to each component in the composition, unless otherwise specified.

[0013] In this specification, (meth)acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl group and (meth)acrylic copolymer.

[0014] In this specification, "solid at 30°C" means that the melting point or softening point is 30°C or higher, or, if the substance does not have a melting point or softening point, the viscosity measured at 30°C is 3000 Pa·s or higher. "Liquid at 30°C" means that the melting point or softening point is less than 30°C, or, if the substance does not have a melting point or softening point, the viscosity measured at 30°C is less than 3000 Pa·s. The softening point refers to the value measured by the ring-and-ball method in accordance with JIS K7234:1986, JIS K6910:2007, etc. The viscosity measured at 30°C refers to the value measured using an E-type viscometer or a B-type viscometer for the component (compound) held at 30°C.

[0015] [Film-like adhesive] Figure 1 is a schematic cross-sectional view showing one embodiment of a film-like adhesive. The film-like adhesive 10A shown in Figure 1 is thermosetting and goes through a semi-cured (B stage) state to a (fully) cured (C stage) state after curing treatment. The film-like adhesive 10A may be provided on a support film 20 as shown in Figure 1. The film-like adhesive 10A may be a die bonding film used for bonding a semiconductor chip to a support member or to semiconductor chips to each other.

[0016] The support film 20 is not particularly limited, but examples include films made of polyester, polyethylene, polypropylene, polyethylene terephthalate, polyimide, polyetherimide, polyethylene naphthalate, polymethylpentene, and polytetrafluoroethylene. The support film 20 may be a multilayer film made by combining two or more types of films. The support film 20 may be surface-treated with a release agent such as a silicone-based or silane-based agent. The support film 20 may be surface-treated with UV treatment, corona discharge treatment, polishing treatment, etching treatment, etc. The thickness of the support film 20 may be, for example, 10 to 200 μm or 20 to 170 μm.

[0017] The film-like adhesive 10A contains thermally conductive particles (hereinafter sometimes referred to as "component (A)"), epoxy resin (hereinafter sometimes referred to as "component (B)"), and phenolic resin (hereinafter sometimes referred to as "component (C)"). In addition, the film-like adhesive 10A may further contain, in addition to components (A), (B), and (C), an elastomer (hereinafter sometimes referred to as "component (D)"), a coupling agent (hereinafter sometimes referred to as "component (E)"), a curing accelerator (hereinafter sometimes referred to as "component (F)"), and other components.

[0018] (A) Component: Thermally conductive particles Component (A) is a component for improving heat dissipation when a film-like adhesive is applied to a semiconductor device. Component (A) may be particles containing a substance with a thermal conductivity (at 20°C) of 10 W / (m·K) or more. If component (A) is such particles, heat dissipation can be further improved. The thermal conductivity (at 20°C) may be, for example, 2000 W / (m·K) or less.

[0019] Examples of materials with a thermal conductivity (at 20°C) of 10 W / (m·K) or higher include oxides such as aluminum oxide (alumina, thermal conductivity (at 20°C): 30 W / (m·K)), zinc oxide (thermal conductivity (at 20°C): 60 W / (m·K)), magnesium oxide (thermal conductivity (at 20°C): 50 W / (m·K)), and boron nitride (thermal conductivity (at 20°C) of hexagonal boron nitride (h-BN): 60 W / (m·K) (representative value for sintered bodies. The crystal has great anisotropy, and the face Inward thermal conductivity reaches several hundred W / (m·K).), cubic boron nitride (c-BN) thermal conductivity (20°C): 300 W / (m·K) (high-quality materials exceed 1000 W / (m·K)), aluminum nitride (thermal conductivity (20°C): 160 W / (m·K)), silicon nitride (thermal conductivity (20°C): 25 W / (m·K)), and other nitrides, diamond (thermal conductivity (20°C): 2000 W / (m·K)), silicon carbide (thermal conductivity (20°C): 19 Carbides such as 5 W / (m·K), silver (thermal conductivity (20°C): 430 W / (m·K)), copper (thermal conductivity (20°C): 400 W / (m·K)), gold (thermal conductivity (20°C): 320 W / (m·K)), aluminum (thermal conductivity (20°C): 240 W / (m·K)), magnesium (thermal conductivity (20°C): 160 W / (m·K)), tungsten (thermal conductivity (20°C): 170 W / (m·K)), molybdenum (thermal conductivity (20°C): 14 Examples of metals with high thermal conductivity include 0 W / (m·K), zinc (thermal conductivity (20°C): 120 W / (m·K)), nickel (thermal conductivity (20°C): 90 W / (m·K)), iron (thermal conductivity (20°C): 80 W / (m·K)), platinum (thermal conductivity (20°C): 70 W / (m·K)), tin (thermal conductivity (20°C): 70 W / (m·K)), lead (thermal conductivity (20°C): 35 W / (m·K)), and titanium (thermal conductivity (20°C): 20 W / (m·K)).

[0020] Component (A) may, in one embodiment, be particles containing a substance having a thermal conductivity (at 20°C) of 200 W / (m·K) or more. The thermal conductivity (at 20°C) may be, for example, 250 W / (m·K) or more, 300 W / (m·K) or more, or 350 W / (m·K) or more, and may be 1000 W / (m·K) or less, 800 W / (m·K) or less, or 600 W / (m·K) or less.

[0021] In one embodiment, component (A) may be particles containing at least one substance selected from the group consisting of silver, copper, and gold.

[0022] Component (A) may be particles containing silver, as it has excellent thermal conductivity and is resistant to oxidation. The particles containing silver may be, for example, particles composed of silver (particles composed of silver alone, silver particles) or silver-coated metal particles in which the surface of metal particles (copper particles, etc.) is coated with silver. Examples of silver-coated metal particles include silver-coated copper particles. Component (A) may be particles composed of silver.

[0023] The silver particles are not particularly limited, but examples include silver particles produced by reduction (silver particles produced by liquid-phase (wet) reduction using a reducing agent), silver particles produced by atomization, etc. (A) The silver particles as component may be silver particles produced by reduction.

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

[0025] The average particle size of component (A) is 1.0 to 2.5 μm. When the average particle size of component (A) is 1.0 μm or larger, it tends to prevent viscosity increase when preparing adhesive varnish, allow the desired amount of component (A) to be included in the film-like adhesive, and ensure the wettability of the film-like adhesive to the substrate, resulting in better adhesion. When the average particle size of component (A) is 2.5 μm or smaller, the film moldability is improved, and the heat dissipation due to the addition of component (A) can be further enhanced. Furthermore, when the average particle size of component (A) is 2.5 μm or smaller, the thickness of the film-like adhesive can be made thinner, allowing for higher stacking of semiconductor chips, and further preventing the occurrence of cracks in semiconductor chips due to component (A) protruding from the film-like adhesive. The average particle size of component (A) may be 1.1 μm or more, or 1.2 μm or more, and may be 2.2 μm or less, 2.0 μm or less, 1.9 μm or less, 1.8 μm or less, 1.7 μm or less, or 1.6 μm or less.

[0026] In this specification, the average particle size of component (A) is defined as the particle size when its ratio (volume fraction) to the total volume of component (A) is 50% (Laser 50% particle size (D ５０ )) means. Average particle size (D ５０ The particle size can be determined by measuring a suspension of component (A) in water using a laser scattering particle size analyzer (e.g., Microtrac) and the resulting suspension.

[0027] The content of component (A) may be 60% by mass or more based on the total amount of the film-like adhesive, and may be 62% by mass or more, 64% by mass or more, 66% by mass or more, 68% by mass or more, 70% by mass or more, 72% by mass or more, 74% by mass or more, 75% by mass or more, or 76% by mass or more. When the content of component (A) is 60% by mass or more based on the total amount of the film-like adhesive, the thermal conductivity of the film-like adhesive can be improved, and the heat dissipation of the semiconductor device can be further improved. The content of component (A) may be, for example, 85% by mass or less, 83% by mass or less, 82% by mass or less, 81% by mass or less, or 80% by mass or less based on the total amount of the film-like adhesive. When the content of component (A) is 85% by mass or less based on the total amount of the film-like adhesive, other components can be included in a more sufficient amount in the film-like adhesive. This ensures the wettability of the film-like adhesive to the adherend and allows for better adhesion. The content of component (A) in the adhesive composition when forming the film-like adhesive may be the same as the range described above.

[0028] (B) Component: Epoxy resin Component (B) can be used without particular limitations as long as it has an epoxy group in its molecule. Examples of component (B) include bisphenol A type epoxy resin; bisphenol F type epoxy resin; bisphenol S type epoxy resin; phenol novolac type epoxy resin; cresol novolac type epoxy resin; bisphenol A novolac type epoxy resin; bisphenol F novolac type epoxy resin; stilbene type epoxy resin; triazine skeleton-containing epoxy resin; fluorene skeleton-containing epoxy resin; triphenolmethane type epoxy resin; biphenyl type epoxy resin; xylylene type epoxy resin; biphenyl aralkyl type epoxy resin; naphthalene type epoxy resin; and diglycidyl ether compounds of polycyclic aromatics such as polyfunctional phenols and anthracenes. Among these, component (B) may include cresol novolac type epoxy resin, bisphenol F type epoxy resin, or bisphenol A type epoxy resin from the viewpoint of the tackiness and flexibility of the film. Bisphenol F type epoxy resins, for example, often have a relatively low softening point, with many having a softening point of 40°C or below.

[0029] Component (B) may contain a liquid epoxy resin that is liquid at 30°C (hereinafter sometimes referred to as "component (Ba)"). Component (B) may be a combination of component (Ba) and a solid epoxy resin that is solid at 30°C (hereinafter sometimes referred to as "component (Bb)"). Component (B) tends to have an easier time improving the storage modulus after curing by containing component (Ba). Also, component (B) being a combination of component (Ba) and component (Bb) tends to make it easier to achieve thin films.

[0030] Examples of commercially available products containing component (Ba) include YDF-8170C (product name, manufactured by Nippon Steel Chemical & Material Co., Ltd., bisphenol F type epoxy resin, epoxy equivalent: 165 g / eq) and EXA-830CRP (product name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 159 g / eq).

[0031] Examples of commercially available products containing component (Bb) include YDCN-700-10 (product name, manufactured by Nippon Steel Chemical & Material Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent: 210 g / eq, softening point: 80°C), N-500P-10 (product name, manufactured by DIC Corporation, cresol novolac type epoxy resin, epoxy equivalent: 204 g / eq, softening point: 84°C), HP-4710 (product name, manufactured by DIC Corporation, naphthalene type epoxy resin, epoxy equivalent: 170 g / eq, softening point: 95°C), and NC-7000L (product name, manufactured by Nippon Kayaku Co., Ltd., naphthalene type epoxy resin, epoxy equivalent: 230 g / eq, softening point: 88°C).

[0032] The epoxy equivalent of component (B) is not particularly limited, but may be 80 to 350 g / eq, 100 to 300 g / eq, or 120 to 250 g / eq. The epoxy equivalent of component (B) can be measured, for example, by potentiometric titration in accordance with JIS K7236:2009. Alternatively, the epoxy equivalent of component (B) may be taken from, for example, the manufacturer's catalog value.

[0033] The softening point of component (B) can be measured, for example, by the ring-and-ball method in accordance with JIS K7234:1986. Alternatively, the softening point of component (B) may be taken from, for example, the manufacturer's catalog value.

[0034] When component (B) is a combination of component (Ba) and component (Bb), the content of component (Ba) may be 20% by mass or more, 30% by mass or more, or 35% by mass or more, and may be 80% by mass or less, 70% by mass or less, or 65% by mass or less, based on the total amount of component (B). The content of component (Ba) in component (B) in the adhesive composition when forming a film-like adhesive may be the same as the above range.

[0035] If component (B) is a combination of component (Ba) and component (Bb), the content of component (Ba) may be 1 to 10% by mass based on the total amount of the film-like adhesive. The content of component (Ba) may be 2% by mass or more, 3% by mass or more, or 3.5% by mass or more, and may be 8% by mass or less, 7% by mass or less, or 6% by mass or less, based on the total amount of the film-like adhesive. The content of component (Ba) in the adhesive composition when forming the film-like adhesive may be the same as the above range.

[0036] When component (B) is a combination of component (Ba) and component (Bb), the content of component (Bb) may be 20% by mass or more, 30% by mass or more, or 35% by mass or more, and may be 80% by mass or less, 70% by mass or less, or 60% by mass or less, based on the total amount of component (B). The content of component (Bb) in component (B) in the adhesive composition when forming a film-like adhesive may be the same as the above range.

[0037] When the component (B) is a combination of the component (Ba) and the component (Bb), the content of the component (Bb) may be 0.1 to 7% by mass based on the total amount of the film adhesive. The content of the component (Bb) may be 0.5% by mass or more, 1% by mass or more, or 1.5% by mass or more, and may be 6% by mass or less, 5% by mass or less, or 4% by mass or less based on the total amount of the film adhesive. In addition, the content of the component (Bb) in the adhesive composition when forming the film adhesive may be the same as the above range.

[0038] The content of the component (B) may be 2% by mass or more, 4% by mass or more, or 6% by mass or more based on the total amount of the film adhesive. When the content of the component (B) is in such a range, there is a tendency to more easily improve the storage elastic modulus after curing. Since the content of the component (A) can be sufficiently ensured, the content of the component (B) may be 15% by mass or less, 12% by mass or less, or 10% by mass or less based on the total amount of the film adhesive. In addition, the content of the component (B) in the adhesive composition when forming the film adhesive may be the same as the above range.

[0039] Component (C): Phenolic resin The component (C) can act as a curing agent for the component (B), that is, it can be a curing agent for the epoxy resin. When the film adhesive contains the component (C), the film adhesive can be highly crosslinked and the storage elastic modulus after curing can be improved.

[0040] In one embodiment, the component (C) includes a phenolic resin having a hydroxyl equivalent of 185 g / eq or more (hereinafter sometimes referred to as the "component (Ca)"). When the component (C) includes the component (Ca), the heat dissipation property of the obtained semiconductor device tends to be improved. The reason for such an effect is not necessarily clear, but the inventors believe that by using a phenolic resin having a large hydroxyl equivalent, the cured resin can be arranged more regularly, making it easier for lattice vibrations to be transmitted.

[0041] The hydroxyl equivalent of the (Ca) component is 185 g / eq or more, for example, 190 g / eq or more, 195 g / eq or more, 200 g / eq or more, 205 g / eq or more, 210 g / eq or more, or 215 g / eq or more. The hydroxyl equivalent of the (Ca) component may be, for example, 250 g / eq or less. The hydroxyl equivalent can be measured by titration using, for example, the acetylation method with acetic anhydride. Also, the hydroxyl equivalent of the (C) component may be, for example, the catalog value of the supplier. In this specification, when the hydroxyl equivalent is expressed in a range in the catalog value of the supplier or the like, the average value of the maximum value and the minimum value is defined as the hydroxyl equivalent.

[0042] Examples of the (Ca) component include phenolic resins having a biphenyl skeleton. Phenolic resins having a biphenyl skeleton tend to have a relatively high hydroxyl equivalent.

[0043] The phenolic resin having a biphenyl skeleton may be, for example, a phenolic resin having a structure in which an aromatic ring having a phenolic hydroxyl group and a linking group having a biphenyl skeleton are (alternately) bonded.

[0044] In the aromatic ring having a phenolic hydroxyl group, examples of the aromatic ring include a benzene ring, a naphthalene ring, etc. In the aromatic ring, the number of phenolic hydroxyl groups may be, for example, 1 or more, and may be 3 or less or 2 or less.

[0045] The linking group having a biphenyl skeleton is a group for linking aromatic rings having a phenolic hydroxyl group. The linking group having a biphenyl skeleton may be, for example, a divalent group. The linking group having a biphenyl skeleton may contain an alkylene group (for example, a methylene group, an ethylene group, a propylene group, etc.) at both ends of the biphenyl skeleton in order to bond to another aromatic ring as the linking target. Also, a part of the -CH ２ - may be substituted with -O- or the like.

[0046] Examples of phenolic resins having a biphenyl skeleton include the phenolic resin represented by formula (1) and the phenolic resin represented by formula (2). The phenolic resins represented by formulas (1) and (2) can also be called biphenyl-type phenol novolac resins. Biphenyl-type phenol novolac resins tend to have a relatively high hydroxyl group equivalent.

[0047]

[0048] In equation (1), m1 represents an integer greater than or equal to 1.

[0049] Examples of commercially available phenolic resins represented by formula (1) include HE200C-10 (trade name, manufactured by Air Water Performance Chemical Co., Ltd., hydroxyl group equivalent: 204 g / eq, softening point: 70°C), KAYAHARD GPH-65 (trade name, manufactured by Nippon Kayaku Co., Ltd., hydroxyl group equivalent: 200 g / eq, softening point: 65°C), KAYAHARD Examples include GPH-103 (trade name, manufactured by Nippon Kayaku Co., Ltd., hydroxyl group equivalent: 230 g / eq, softening point: 103°C), MEHC-7851SS (trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Co., Ltd.), hydroxyl group equivalent: 203 g / eq, softening point: 67°C), MEHC-7851S (trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Co., Ltd.), hydroxyl group equivalent: 206 g / eq, softening point: 73°C), MEHC-7851M (trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Co., Ltd.), hydroxyl group equivalent: 210 g / eq, softening point: 77°C), MEHC-7851H (trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Co., Ltd.), hydroxyl group equivalent: 218 g / eq, softening point: 83°C), etc.

[0050]

[0051] In equation (2), m² and n² each independently represent an integer greater than or equal to 1.

[0052] Examples of commercially available phenolic resins represented by formula (2) include HE610C-07 (trade name, manufactured by Air Water Performance Chemical Co., Ltd., hydroxyl group equivalent: 190 g / eq, softening point: 74°C).

[0053] Component (C) in one embodiment includes a phenol resin having a biphenyl skeleton. The phenol resin having a biphenyl skeleton may be a biphenyl-type phenol novolac resin, and may be at least one selected from the group consisting of phenol resins represented by formula (1) and phenol resins represented by formula (2).

[0054] Component (C) may further contain a phenol resin having a hydroxyl group equivalent of less than 185 g / eq (hereinafter sometimes referred to as "component (Cb)"), to the extent that it does not impair the effects of the present disclosure. Component (Cb) may be a phenol resin other than a phenol resin having a biphenyl skeleton.

[0055] Examples of commercially available (Cb) components include MEH-7500 (product name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), trisphenylmethane-type phenol novolac resin, hydroxyl group equivalent: 97 g / eq, softening point: 110°C), H-4 (product name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), phenylaralkyl-type phenol resin, hydroxyl group equivalent: 105 g / eq, softening point: 69°C), PSM-4326 (product name, manufactured by Gun-ei Chemical Industry Co., Ltd., phenol novolac resin, hydroxyl group equivalent: 105 g / eq, softening point: 120°C), HF-1M (product name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), phenol novolac resin, hydroxyl group equivalent: 106 g / eq, softening point: 84°C), and HF-3M. Examples include (product name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Co., Ltd.), phenol novolac resin, hydroxyl group equivalent: 107 g / eq, softening point: 96°C), MEH-7800-4S (product name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Co., Ltd.), xylylene-type phenol resin, hydroxyl group equivalent: 173 g / eq, softening point: 63°C), MEH-7800M (product name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Co., Ltd.), phenyl aralkyl-type phenol resin, hydroxyl group equivalent: 174 g / eq, softening point: 82°C), HE910-10 (product name, manufactured by Air Water Performance Chemical Co., Ltd., trisphenylmethane-type phenol novolac resin, hydroxyl group equivalent: 101 g / eq, softening point: 83°C), etc.

[0056] The hydroxyl group equivalent of component (Cb) may be, for example, 140 g / eq or more, 150 g / eq or more, or 160 g / eq or more, and may be 180 g / eq or less, or 175 g / eq or less.

[0057] The total hydroxyl group equivalent of the (Ca) and (Cb) components may be, for example, 185 g / eq or more, 190 g / eq or more, 195 g / eq or more, or 200 g / eq or more. The total hydroxyl group equivalent of the (Ca) and (Cb) components may be, for example, 250 g / eq or less. Note that the total hydroxyl group equivalent of the (Ca) and (Cb) components represents the weighted average of the hydroxyl group equivalents of the (Ca) component and the (Cb) component.

[0058] The softening point of component (C) is not particularly limited, but may be, for example, 150°C or lower, 130°C or lower, 110°C or lower, or 90°C or lower. The softening point of component (C) may be, for example, 50°C or higher, 60°C or higher, or 65°C or higher. The softening point of component (C) can be measured, for example, by the ring-sphere method in accordance with JIS K6910:2007. The softening point of component (C) may be, for example, the value in the manufacturer's catalog.

[0059] The content of component (Ca) may be 70% by mass or more, based on the total amount of component (C). When the content of component (Ca) is 70% by mass or more, based on the total amount of component (C), even if the material is stored at a relatively low temperature for a long period of time before curing and then cured, when thermally conductive particles are highly packed, it is possible to suppress the time-dependent decrease in the storage modulus at high temperatures after curing. The reason for this effect is not entirely clear, but the inventors believe that component (Ca) with a large hydroxyl group equivalent, especially phenolic resins with a rigid molecular skeleton such as a biphenyl skeleton, has the effect of suppressing phase separation and aggregation of resin components during low-temperature storage before curing. As a result, curing proceeds from a uniform state even after long-term storage, and a dense three-dimensional crosslinked network is formed. Consequently, the structural stability of the cured product at high temperatures is improved, and the decrease in the storage modulus is suppressed. The content of component (Ca) may be 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more, based on the total amount of component (C). The content of component (Ca) may be 100% by mass or less, based on the total amount of component (C). The content of component (Ca) may be 100% by mass, based on the total amount of component (C). The content of component (Ca) in component (C) of the adhesive composition when forming a film-like adhesive may be the same as the above range.

[0060] The content of component (Cb) may be 20% by mass or less, 15% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total amount of component (C). The content of component (Cb) may be 0% by mass or more, based on the total amount of component (C). The content of component (Cb) may be 0% by mass, based on the total amount of component (C). The content of component (Cb) in component (C) of the adhesive composition when forming a film-like adhesive may be the same as the above range.

[0061] The ratio of the number of equivalent epoxy groups in component (B) to the number of equivalent hydroxyl groups in component (C) (epoxy groups / hydroxyl groups) 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 from the viewpoint of curability. When the equivalent ratio is 0.30 / 0.70 or higher, more sufficient curability tends to be obtained. When the equivalent ratio is 0.70 / 0.30 or lower, it is possible to prevent the viscosity from becoming too high and to obtain more sufficient fluidity.

[0062] The content of component (C) may be 2% by mass or more, 4% by mass or more, or 6% by mass or more, based on the total amount of the film-like adhesive. When the content of component (C) is within this range, it tends to be easier to improve the storage modulus after curing. The content of component (C) may be 15% by mass or less, 12% by mass or less, or 10% by mass or less, based on the total amount of the film-like adhesive, since the content of component (A) can be sufficiently ensured. The content of component (C) in the adhesive composition when forming the film-like adhesive may be the same as the above range.

[0063] The total content of component (B) and component (C) may be 4% by mass or more, 8% by mass or more, or 12% by mass or more, based on the total amount of the film-like adhesive. When the total content of component (B) and component (C) is within this range, it tends to be easier to improve the storage modulus after curing. The total content of component (B) and component (C) may be 30% by mass or less, 24% by mass or less, or 20% by mass or less, based on the total amount of the film-like adhesive, since the content of component (A) can be sufficiently ensured. The total content of component (B) and component (C) in the adhesive composition when forming the film-like adhesive may be the same as the above range.

[0064] (D) Component: Elastomer Component (D) can be a thermoplastic resin, or a resin that is thermoplastic at least in its uncured state and forms a crosslinked structure after heating. Component (D) may be a (meth)acrylic copolymer having a reactive group (hereinafter sometimes referred to as "reactive group-containing (meth)acrylic copolymer") from the viewpoint of excellent shrinkage, heat resistance, and stress relaxation.

[0065] Examples of (meth)acrylic copolymers include (meth)acrylic acid ester copolymers such as acrylic glass and acrylic rubber. The (meth)acrylic copolymer may be acrylic rubber. The acrylic rubber may be mainly composed of acrylic acid ester and formed by copolymerization of (meth)acrylic acid ester and monomers selected from acrylonitrile.

[0066] Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate. Examples of (meth)acrylic acid ester copolymers include copolymers containing butyl acrylate and acrylonitrile as copolymer components, and copolymers containing ethyl acrylate and acrylonitrile as copolymer components.

[0067] A reactive group-containing (meth)acrylic copolymer may be a reactive group-containing (meth)acrylic copolymer that contains a reactive group-containing (meth)acrylic monomer as a copolymer component. Such a reactive group-containing (meth)acrylic copolymer can be obtained by copolymerizing a monomer mixture containing a reactive group-containing (meth)acrylic monomer and the above monomer.

[0068] Examples of reactive groups that improve heat resistance include epoxy groups, carboxyl groups, (meth)acryloyl groups, hydroxyl groups, and episulfide groups. The reactive group may be an epoxy group or a carboxyl group from the viewpoint of crosslinking.

[0069] In this embodiment, the reactive group-containing (meth)acrylic copolymer may be an epoxy group-containing (meth)acrylic copolymer containing an epoxy group-containing (meth)acrylic monomer as a copolymer component. In this case, examples of epoxy group-containing (meth)acrylic monomers include glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate. From the viewpoint of heat resistance, the reactive group-containing (meth)acrylic monomer may be glycidyl (meth)acrylate.

[0070] The glass transition temperature (Tg) of component (D) is, for example, -50 to 20°C, or it may be -30 to 15°C. If the Tg of component (D) is -50°C or higher, it is easier to suppress the film-like adhesive from becoming excessively soft, and excellent handling and adhesion can be achieved. On the other hand, if the Tg of component (D) is 20°C or lower, it is easier to ensure the flexibility of the film-like adhesive, and excellent adhesive strength can be achieved. In addition, even if there are irregularities on the adherend surface, the film-like adhesive can easily follow the irregularities, and excellent adhesion can be achieved.

[0071] The Tg of component (D) is the intermediate glass transition temperature value obtained by differential scanning calorimetry (DSC). Specifically, the Tg of component (D) is the intermediate glass transition temperature calculated by measuring the heat change under the conditions of a heating rate of 10°C / min and a measurement temperature of -80 to 80°C, using a method in accordance with JIS K7121:1987. If component (D) is a commercially available product, the value listed in the catalog may be used.

[0072] The weight-average molecular weight of component (D) may be between 100,000 and 2,000,000. A weight-average molecular weight of 100,000 or more makes it easier to ensure heat resistance. On the other hand, a weight-average molecular weight of 2,000,000 or less makes it easier to suppress the decrease in flow and adhesion. The weight-average molecular weight of component (D) may also be between 400,000 and 1,500,000 or between 500,000 and 1,200,000. The weight-average molecular weight is the polystyrene equivalent value obtained using a calibration curve with standard polystyrene in gel permeation chromatography (GPC). If multiple peaks are observed in GPC, the weight-average molecular weight attributable to the peak with the highest peak intensity is defined as the weight-average molecular weight in this specification.

[0073] Examples of commercially available components (D) include SG-P3, SG-80H (both manufactured by Nagase ChemteX Corporation), and KH-CT-865 (manufactured by Resonaq Corporation).

[0074] The content of component (D) may be, for example, 1 to 15% by mass, 2 to 10% by mass, or 3 to 8% by mass, based on the total amount of the film-like adhesive. When the content of component (D) is within the above range, the content of component (A) can be sufficiently ensured, shrinkage associated with the thermal curing of the film-like adhesive can be suppressed, and excellent adhesion after thermal curing tends to be easily achieved. The content of component (D) in the adhesive composition when forming the film-like adhesive may be the same as the above range.

[0075] Component (A), component (B), component (C), and component (D) may be the main components of the film-like adhesive of this embodiment. The total content of component (A), component (B), component (C), and component (D) may be, for example, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 96% by mass or more, 97% by mass or more, 98% by mass or more, 99% by mass or more, 99.5% by mass or more, 99.7% by mass or more, or 99.9% by mass or more, based on the total amount of the film-like adhesive. The total content of component (A), component (B), component (C), and component (D) may be, for example, 100% by mass or less, 99.9% by mass or less, 99.7% by mass or less, or 99.5% by mass or less, based on the total amount of the film-like adhesive.

[0076] (E) Component: Coupling agent Component (E) may be a silane coupling agent. Examples of silane coupling agents include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane.

[0077] (F) component: curing accelerator. Examples of (F) component include imidazoles and their derivatives, organophosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts, etc. Among these, from the viewpoint of reactivity, (F) component may be imidazoles and their derivatives.

[0078] Examples of imidazoles and their derivatives include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, and 2-phenylimidazole.

[0079] The film-like adhesive may further contain other components. Examples of other components include pigments, ion capture agents, antioxidants, and so on.

[0080] The total content of component (E), component (F), and other components may be 0% by mass or more, 0.01% by mass or more, 0.03% by mass or more, or 0.05% by mass or more, based on the total amount of the film-like adhesive, and may be 10% by mass or less, 5% by mass or less, 3% by mass or less, 2% by mass or less, 1% by mass or less, 0.8% by mass or less, 0.5% by mass or less, or 0.3% by mass or less. The total content of component (E), component (F), and other components in the adhesive composition when forming the film-like adhesive may be the same as the above ranges.

[0081] The thickness of the film-like adhesive 10A may be, for example, 3 to 200 μm. When the thickness of the film-like adhesive 10A is 3 μm or more, the adhesive strength with the semiconductor wafer tends to be sufficient, and when the thickness of the film-like adhesive 10A is 200 μm or less, the thermal conductivity tends to be sufficient. From the viewpoint of adhesive strength and thinning of semiconductor devices, the thickness of the film-like adhesive 10A may be 5 μm or more, 10 μm or more, 15 μm or more, or 20 μm or more, and may also be 180 μm or less, 150 μm or less, 120 μm or less, 100 μm or less, 80 μm or less, 60 μm or less, or 40 μm or less. The thickness of the film-like adhesive 10A can be determined, for example, by measuring the thickness at five locations on the cross-section of the film-like adhesive 10A using a scanning electron microscope and calculating the average of the measured values.

[0082] The film-like adhesive 10A shown in Figure 1 is formed by molding an adhesive composition containing component (A), component (B), and component (C), as well as additional components as needed, into a film. Such a film-like adhesive 10A can be formed by applying the adhesive composition to a support film. In forming the film-like adhesive 10A, a varnish (adhesive varnish) containing the adhesive composition and a solvent may also be used. When using an adhesive varnish, the adhesive varnish can be prepared by mixing or kneading component (A), component (B), and component (C), as well as additional components as needed, in a solvent, applying the obtained adhesive varnish to a support film, and removing the solvent by heating and drying to obtain the film-like adhesive 10A.

[0083] Mixing or kneading can be carried out using conventional agitators, dispersers, three-roll mills, ball mills, and other dispersers, in appropriate combinations.

[0084] The solvent used in the preparation of the adhesive varnish is not limited as long as it can uniformly dissolve, knead, or disperse each component, and conventionally known solvents can be used. Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, as well as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, toluene, and xylene. From the viewpoint of drying speed and cost, the solvent may be methyl ethyl ketone or cyclohexanone. The concentration of solid components in the adhesive varnish may be 10 to 80% by mass based on the total amount of the adhesive varnish.

[0085] Known methods can be used to apply the adhesive varnish to the support film, such as the knife coating method, roll coating method, spray coating method, gravure coating method, bar coating method, and curtain coating method. The heating and drying conditions are not particularly limited as long as the solvent used is sufficiently evaporated, but may be 50 to 150°C for 1 to 30 minutes.

[0086] The thermal conductivity (at 35°C) of the film-like adhesive 10A after heat curing (C-stage state) may be 7.0 W / (m·K) or higher, and may be 7.5 W / (m·K) or higher, 7.8 W / (m·K) or higher, 8.0 W / (m·K) or higher, 8.2 W / (m·K) or higher, or 8.5 W / (m·K) or higher. When the thermal conductivity is 7.0 W / (m·K) or higher, the heat dissipation performance of the semiconductor device tends to be better. There is no particular upper limit to the thermal conductivity (at 35°C) of the film-like adhesive 10A after heat curing (C-stage state), but it may be 20 W / (m·K) or lower or 15 W / (m·K) or lower.

[0087] In this specification, the thermal conductivity (at 35°C) of the film-like adhesive 10A after heat curing (C-stage state) can be measured, for example, by the following method. First, a sample for thermal conductivity measurement is prepared using an adhesive varnish containing each component. The adhesive varnish is degassed under vacuum and poured into a Teflon® mold to a thickness of approximately 500 to 700 μm, and left to stand for 12 hours or more. The Teflon mold containing the adhesive varnish is heated on a hot plate (manufactured by AS ONE Corporation) at 70°C for 1 hour, followed by 110°C for 20 minutes. Next, the Teflon mold is placed in a clean oven (manufactured by ESPEC Corporation) and heat-cured at 110°C for 1 hour, followed by 170°C for 3 hours to obtain a sample in the C-stage state. The prepared sample is cut into 1 cm x 1 cm pieces, and the thermal conductivity is measured using these pieces as a sample for thermal conductivity measurement under the following measurement items / conditions.

[0088] (Calculation of Thermal Conductivity) The thermal conductivity λ in the thickness direction of a sample for thermal conductivity measurement is calculated by the following formula. The thermal diffusivity α, specific heat Cp, and density ρ are measured by the following method. A higher thermal conductivity λ means that the heat dissipation is better in semiconductor devices. 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 )

[0089] (Measurement of thermal diffusivity α) A measurement sample is prepared by blackening both sides of the sample for thermal conductivity measurement with graphite spray. Then, the thermal diffusivity α of this measurement sample is measured using the laser flash method (xenon flash method) with the following measurement device and conditions, for example: • Measurement device: Thermal diffusivity measuring device (manufactured by Netch Japan Co., Ltd., product name: LFA447 nanoflash) • Pulse width of pulsed light irradiation: 0.04 ms • Applied voltage of pulsed light irradiation: 180 V • Processing of measurement sample: Blackening both sides of the sample for thermal conductivity measurement with graphite spray • Measurement ambient temperature: 35°C

[0090] (Measurement of Specific Heat Cp (35°C)) The specific heat Cp (35°C) of a sample for thermal conductivity measurement is determined, for example, by performing differential scanning calorimetry (DSC) using the following measuring device under the following conditions: • Measuring device: Differential scanning calorimeter (e.g., Rigaku Corporation, product name: High-sensitivity differential scanning calorimeter DSC8231) • Reference material: Sapphire • Heating rate: 12°C / min • Heating temperature range: 25-75°C

[0091] (Measurement of Density ρ) The density ρ of the sample for thermal conductivity measurement is measured by the Archimedes method using the following measuring device under the following conditions: • Measuring device: Electronic hydrometer (e.g., Alpha Mirage Co., Ltd., product name: SD200L) • Water temperature: 25°C

[0092] [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 comprises a base layer 40, an adhesive layer 30, and an adhesive layer 10 consisting of a film-like adhesive 10A, in this order. The dicing and die bonding integrated film 100 can also be said to comprise a dicing tape 50 (dicing film) comprising a base layer 40 and an adhesive layer 30 provided on the base layer 40, and an adhesive layer 10 provided on the adhesive layer 30 of the dicing tape 50. The dicing and die bonding integrated film 100 may be in the form of a film, a sheet, a tape, etc. The dicing and die bonding integrated film 100 may have a support film 20 provided on the surface of the adhesive layer 10 opposite to the adhesive layer 30.

[0093] For example, the base material layer 40 in the dicing tape 50 can be the same as that of the support film 20.

[0094] The adhesive layer 30 in the dicing tape 50 is not particularly limited as long as it has sufficient adhesive strength to prevent semiconductor chips from scattering during dicing and low enough adhesive strength to avoid damaging the semiconductor chips during the subsequent semiconductor chip pickup process; conventionally known adhesives in the field of dicing tapes can be used. The adhesive layer 30 may be an adhesive layer containing a non-curing type of adhesive or an adhesive layer containing a UV-curing type of adhesive. The adhesive layer 30 may be an adhesive layer containing a non-curing type of adhesive. If the adhesive layer contains a UV-curing type of adhesive, the adhesiveness of the adhesive layer can be reduced by irradiation with ultraviolet light.

[0095] 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 viewpoint of economy and ease of handling of the film.

[0096] The dicing-die bonding integrated film 100 shown in Figure 2 can be obtained by a manufacturing method comprising the steps of: preparing a dicing tape 50 comprising a film-like adhesive 10A and a base layer 40 and an adhesive layer 30 provided on the base layer 40; and bonding the film-like adhesive 10A and the adhesive layer 30 of the dicing tape 50. Known methods can be used for bonding the film-like adhesive 10A and the adhesive layer 30 of the dicing tape 50.

[0097] [Semiconductor device and method for manufacturing the same] Figure 3 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a semiconductor device. Figures 3(a), (b), (c), (d), (e), and (f) are schematic cross-sectional views showing each step. In one embodiment, the method for manufacturing a semiconductor device comprises the steps of: attaching a semiconductor wafer W to the adhesive layer 10 of the dicing-die bonding integrated film 100 (wafer lamination step, see Figures 3(a) and (b)); producing a plurality of individual semiconductor chips 60 with adhesive pieces by dicing the semiconductor wafer W to which the adhesive layer 10 has been attached (dicing step, see Figure 3(c)); and bonding the semiconductor chips 60 with adhesive pieces to a support member 80 via adhesive pieces 10a (semiconductor chip bonding step, see Figure 3(f)). The method for manufacturing a semiconductor device may further include, as necessary, a step between the dicing step and the semiconductor chip bonding step, a step of irradiating the adhesive layer 30 with ultraviolet light (through the substrate layer 40) (ultraviolet irradiation step, see Figure 3(d)), a step of picking up the semiconductor chip Wa (semiconductor chip 60 with adhesive piece) to which the adhesive piece 10a has been attached from the adhesive layer 30a (pickup step, see Figure 3(e)), and a step of thermally curing the adhesive piece 10a on the semiconductor chip 60 with adhesive piece bonded to the support member 80 (thermal curing step).

[0098] The method for manufacturing a semiconductor device may further include a step of bonding a semiconductor chip 60 with an adhesive piece (a second semiconductor chip having a second adhesive piece) to the surface of a semiconductor chip (a first semiconductor chip having a first adhesive piece) that is bonded to a support member 80, via an adhesive piece (a second adhesive piece).

[0099] <Wafer Lamination Process> In this process, first, the dicing and die bonding integrated film 100 is placed in a predetermined apparatus. Next, the surface Ws of the semiconductor wafer W is attached to the adhesive layer 10 of the dicing and die bonding integrated film 100 (see Figures 3(a) and 3(b)). The circuit surface of the semiconductor wafer W may be provided on the side opposite to the surface Ws.

[0100] Examples of semiconductor wafers W include single-crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

[0101] <Dicing Process> In this process, the semiconductor wafer W and the adhesive layer 10 are diced to form individual pieces (see Figure 3(c)). Dicing can be performed, for example, from the circuit side of the semiconductor wafer according to a conventional method. In this process, for example, a method called full cut, in which an incision is made up to the adhesive layer 10, a method in which a half-incision is made in the semiconductor wafer W and the wafer is divided by cooling and pulling, or a method of division by laser can be employed. The dicing apparatus used in this process is not particularly limited, and conventionally known apparatus can be used. At this time, a part of the adhesive layer 30, or all of the adhesive layer 30 and a part of the substrate layer 40 may be diced to form individual pieces. In this way, the dicing-die bonding integrated film 100 also functions as a dicing sheet.

[0102] <Ultraviolet Irradiation Step> If the adhesive layer 30 contains an ultraviolet-curable adhesive, the semiconductor device manufacturing method may include an ultraviolet irradiation step. In this step, ultraviolet light is irradiated onto the adhesive layer 30 (through the substrate layer 40) (see Figure 3(d)). In ultraviolet irradiation, the wavelength of the ultraviolet light may be 200 to 400 nm. The ultraviolet irradiation conditions are illuminance and irradiation dose of 30 to 240 mW / cm², respectively. ２ The range and 50-500 mJ / cm ２ It may be within that range.

[0103] <Pickup Process> In this process, the substrate layer 40 is expanded to separate the individual semiconductor chips 60 with adhesive pieces from each other, and the semiconductor chips 60 with adhesive pieces that have been pushed up from the substrate layer 40 side by the needle 72 are picked up from the adhesive layer 30a by the suction collet 74 (see Figure 3(e)). The semiconductor chip 60 with adhesive pieces has a semiconductor chip Wa and an adhesive piece 10a. The semiconductor chip Wa is an individual piece of the semiconductor wafer W, and the adhesive piece 10a is an individual piece of the adhesive layer 10. The adhesive layer 30a is an individual piece of the adhesive layer 30. The adhesive layer 30a may remain on the substrate layer 40 after the semiconductor chips 60 with adhesive pieces have been picked up. In this process, it is not always necessary to expand the substrate layer 40, but expanding the substrate layer 40 can further improve the pickup performance.

[0104] The amount of upward thrust by the needle 72 can be set as appropriate. Furthermore, from the viewpoint of ensuring sufficient pickup even for ultrathin wafers, for example, two or three stages of upward thrust may be performed. In addition, the semiconductor chip 60 with adhesive residue may be picked up by a method other than the method using the suction collet 74.

[0105] <Semiconductor Chip Bonding Process> In this process, the picked-up semiconductor chip 60 with adhesive piece attached is bonded to the support member 80 via the adhesive piece 10a by thermocompression bonding (see Figure 3(f)). Multiple semiconductor chips 60 with adhesive pieces attached may be bonded to the support member 80.

[0106] The heating temperature in the heat-sealing process may be, for example, 80 to 160°C. The load in the heat-sealing process may be, for example, 5 to 15 N. The heating time in the heat-sealing process may be, for example, 0.5 to 20 seconds.

[0107] <Thermosetting Process> In this process, the adhesive piece 10a on the semiconductor chip 60 with adhesive piece attached to the support member 80 is thermoset. By thermosetting the adhesive piece 10a that bonds the semiconductor chip Wa and the support member 80, it becomes a cured adhesive piece 10ac, enabling stronger adhesion and fixation (see Figure 3(f)). When thermosetting, pressure may be applied simultaneously to cure it. The heating temperature in this process can be appropriately changed depending on the components of the adhesive 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. Note that the temperature or pressure may be changed in stages.

[0108] The method for manufacturing a semiconductor device may further include, if necessary, a step of bonding a semiconductor chip 60 with an adhesive piece (a second semiconductor chip with an adhesive piece having a second adhesive piece) to the surface of the semiconductor chip (first semiconductor chip) of the semiconductor chip 60 with an adhesive piece (a first semiconductor chip with an adhesive piece having a first adhesive piece) bonded to a support member 80, via an adhesive piece (second adhesive piece), by thermocompression bonding. The conditions for thermocompression bonding may be the same as those for thermocompression bonding in the semiconductor chip bonding step. The second adhesive piece in the semiconductor chip with an adhesive piece bonded to the first semiconductor chip may be heat-cured. The heat-curing conditions for the second adhesive piece may be the same as those for heat-curing the adhesive piece 10a in the semiconductor chip 60 with an adhesive piece bonded to the support member 80.

[0109] A method for manufacturing a semiconductor device may, if necessary, include a step (wire bonding step) of electrically connecting the tip of the terminal portion (inner lead) of a support member to the electrode pad on the semiconductor chip with a bonding wire. Examples of bonding wires include gold wire, aluminum wire, copper wire, etc. The temperature during wire bonding may be in the 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 a combination of ultrasonic vibration energy and applied pressure to bond the wire while it is heated within the above temperature range.

[0110] A method for manufacturing a semiconductor device may optionally include a step of sealing a semiconductor chip with a sealing material (sealing step). This step is performed to protect the semiconductor chip or bonding wire mounted on a support member. This step can be performed by molding a sealing resin (sealing resin) in a mold. The sealing resin may be, for example, an epoxy resin. The heat and pressure during sealing embed the support member and residue, preventing delamination due to air bubbles at the adhesive interface.

[0111] The semiconductor device manufacturing method may include, if necessary, a step (post-curing step) to completely cure the sealing resin that is not sufficiently cured in the sealing step. Even if the adhesive piece is not heat-cured in the sealing step, in this step, the adhesive piece can be heat-cured along with the curing of the sealing resin, enabling adhesive fixation. The heating temperature in this step can be appropriately set depending on the type of sealing resin, and may be in the range of 165 to 185°C, for example, and the heating time may be about 0.5 to 8 hours.

[0112] A method for manufacturing a semiconductor device may optionally include a step (heating and melting step) of heating a semiconductor chip with adhesive attached to a support member using a reflow oven. 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 supplied onto a printed circuit board in advance, then heated and melted with 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 heating a localized area. The heating temperature may be, for example, in the range of 240 to 280°C.

[0113] In one embodiment, the method for manufacturing a semiconductor device includes a step of interposing the above-mentioned film-like adhesive between a first semiconductor chip and a support member, or between a first semiconductor chip and a second semiconductor chip different from the first semiconductor chip, to bond the first semiconductor chip and the support member, or the first semiconductor chip and the second semiconductor chip.

[0114] Figure 4 is a schematic cross-sectional view showing one embodiment of a semiconductor device. The semiconductor device 200 shown in Figure 4 comprises a semiconductor chip Wa (first semiconductor chip), 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 adheres the semiconductor chip Wa and the support member 80. The adhesive member 12 includes a cured product of the above-mentioned film-like adhesive (cured product of adhesive piece 10ac). The semiconductor device 200 may further include a second semiconductor chip (not shown) different from the first semiconductor chip, which is laminated on the surface of the semiconductor chip Wa (first semiconductor chip). The 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 sealed by a sealing layer 92 formed from a sealing material. Solder balls 94 may be formed on the surface of the support member 80 opposite to the surface 80A for electrical connection to an external substrate (motherboard) (not shown).

[0115] The semiconductor chip Wa (first semiconductor chip and second semiconductor chip) may be, for example, an IC (integrated circuit). Examples of the support member 80 include lead frames such as 42 alloy lead frames and copper lead frames; plastic films such as polyimide resin and epoxy resin; modified plastic films obtained by impregnating and curing a substrate such as glass nonwoven fabric with plastic such as polyimide resin and epoxy resin; and ceramics such as alumina.

[0116] The semiconductor device 200 has excellent heat dissipation properties because it includes a cured product of the above-mentioned film-like adhesive as the adhesive member 12.

[0117] The present disclosure will be described below in detail based on examples, but the present disclosure is not limited to these examples.

[0118] (Examples 1 and 2 and Comparative Examples 1 and 2) [Preparation of Film-like Adhesives] <Preparation of Adhesive Varnish> Cyclohexanone was added to a mixture of components (A), (B), and (C) in the components and composition ratios (unit: parts by mass) shown in Table 1, and stirred. Then, component (D) was added in the components and composition ratios (unit: parts by mass) shown in Table 1 and stirred, and then components (E) and (F) were added and stirred until each component was homogeneous to prepare the adhesive varnishes of Examples 1 and 2 and Comparative Examples 1 and 2. Note that each component shown in Table 1 means the following, and the values ​​shown in Table 1 mean parts by mass of solids.

[0119] (A) Components: Thermally conductive particles (A-1) Silver particles AG-3-1F (product name, manufactured by DOWA Electronics Co., Ltd., shape: spherical, average particle size (50% particle size of laser (D ５０(1.4 μm) (B) Component: Epoxy resin (Ba) Component: Liquid epoxy resin (Ba-1) EXA-830CRP (Trade name, manufactured by DIC Corporation, Bisphenol F type epoxy resin, Epoxy equivalent: 159 g / eq) (Bb) Component: Solid epoxy resin (Bb-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) Component: Phenolic resin (Ca) Component: Phenolic resin with a hydroxyl group equivalent of 185 g / eq or more (Ca-1) MEHC-7851H (Trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), Hydroxyl group equivalent: 218 g / eq, Softening point: 83°C) (Ca-2) HE200C-10 (product name, manufactured by Air Water Performance Chemicals Inc., hydroxyl group equivalent: 204 g / eq, softening point: 70°C) ・(Cb) component: phenol resin with a hydroxyl group equivalent of less than 185 g / eq (Cb-1) MEH-7800M (product name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), phenyl aralkyl type phenol resin, hydroxyl group equivalent: 174 g / eq, softening point: 82°C) (Cb-2) HE910-10 (product name, manufactured by Air Water Performance Chemicals Inc., trisphenylmethane type phenol novolac resin, hydroxyl group equivalent: 101 g / eq, softening point: 83°C) (D) component: elastomer (D-1) SG-P3 solvent modified product (product name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight-average molecular weight: 800,000, Tg: -7℃) (E) component: coupling agent (E-1) Z-6119 (product name, manufactured by Dow Toray Industries, Ltd., γ-ureidopropyltriethoxysilane) (F) component: curing accelerator (F-1) 2PZ-CN (product name, manufactured by Shikoku Chemicals, Ltd., 1-cyanoethyl-2-phenylimidazole) (F-2) 1B2MZ (product name, manufactured by Shikoku Chemicals, Ltd., 1-benzyl-2-methylimidazole) (F-3) 2PZ-T (product name, manufactured by Shikoku Chemicals, Ltd., 2-phenylimidazole)

[0120] <Preparation of Film - like Adhesive>A polyethylene terephthalate (PET) film with a thickness of 38 μm and subjected to a release treatment was prepared as a support film, and an adhesive varnish was applied onto the PET film. The applied adhesive varnish was heat - dried under the conditions of 90°C for 5 minutes and 130°C for 5 minutes to obtain a laminate comprising the support film and the film - like adhesives of Examples 1 and 2 and Comparative Examples 1 and 2 in the B - stage state on the support film. In the film - like adhesive, the thickness was adjusted to 25 μm according to the coating amount of the adhesive varnish.

[0121] <Evaluation of Film - like Adhesive><Measurement of Thermal Conductivity>- Preparation of Samples for Measuring Thermal Conductivity Using each of the above - mentioned adhesive varnishes, samples for measuring thermal conductivity were prepared. Each adhesive varnish was subjected to vacuum degassing, poured into a Teflon mold to a thickness of about 500 - 700 μm, and allowed to stand for 12 hours or more. The Teflon mold into which each adhesive varnish was poured was heated on a hot plate (manufactured by AS ONE Corporation) at 70°C for 1 hour, and then at 110°C for 20 minutes. Then, the Teflon mold was placed in a clean oven (manufactured by ESPEC Corporation) and heat - cured at 110°C for 1 hour and then at 170°C for 3 hours to obtain a sample in the C - stage state. The prepared sample was cut into 1 cm×1 cm pieces, and the thermal conductivity was measured as a sample for measuring thermal conductivity under the following measurement items / conditions.

[0122] - Calculation of Thermal Conductivity The thermal conductivity λ in the thickness direction of the sample for measuring thermal conductivity was calculated by the following formula. The thermal diffusivity α, specific heat Cp, and density ρ were measured by the following methods. A larger thermal conductivity λ means better heat dissipation in a semiconductor device. Thermal conductivity λ (W / (m·K)) = Thermal diffusivity α (m ２ / s)×Specific heat Cp (J / (kg·K))×Density ρ (g / cm ３ )

[0123] (Measurement of Thermal Diffusivity α) A measurement sample was prepared by blackening both sides of the sample for thermal conductivity measurement with graphite spray. Next, the thermal diffusivity α of this measurement sample was measured using the laser flash method (xenon flash method) with the following measurement device and conditions. • Measurement device: Thermal diffusivity measuring device (manufactured by Netch Japan Co., Ltd., product name: LFA447 nanoflash) • Pulse width of pulsed light irradiation: 0.04 ms • Applied voltage of pulsed light irradiation: 180 V • Processing of measurement sample: Both sides of the sample for thermal conductivity measurement were blackened with graphite spray • Measurement ambient temperature: 35°C

[0124] (Measurement of Specific Heat Cp (35°C)) The specific heat Cp (35°C) of the sample used for thermal conductivity measurement was determined by differential scanning calorimetry (DSC) using the following measuring device under the following conditions: • Measuring device: Differential scanning calorimeter (manufactured by Rigaku Corporation, product name: High-sensitivity differential scanning calorimeter DSC8231) • Reference material: Sapphire • Heating rate: 12°C / min • Heating temperature range: 25-75°C

[0125] (Measurement of Density ρ) The density ρ of the sample for thermal conductivity measurement was measured by the Archimedes method using the following measuring device under the following conditions: • Measuring device: Electronic hydrometer (Alpha Mirage Co., Ltd., product name: SD200L) • Water temperature: 25°C

[0126] <Calculation of the rate of change over time of the storage modulus> (Preparation of sample for measurement) Using the film-like adhesives of Examples 1 and 2 and Comparative Examples 1 and 2, the storage modulus of the cured product at 200°C was measured using the following procedure and the rate of change over time was calculated.

[0127] (1) Preparation of sample for measurement before time-dependent changes Multiple sheets of film-like adhesive were laminated on a hot plate at 60°C using a rubber roll to obtain a laminate (uncured) with a thickness of 180-200 μm and a size of approximately 50 mm x 50 mm. The obtained laminate was cured in an oven at 110°C for 1 hour, and then at 170°C for 3 hours. The obtained cured laminate was cut into strips with a width of 3 mm and a length of 33 mm, and these were used as the sample for measurement before time-dependent changes.

[0128] (2) Preparation of measurement samples after changes over time First, the film-like adhesive (before lamination) immediately after preparation was left to stand under the following conditions: - Example 1, Comparative Example 1 and Comparative Example 2: Left in a constant temperature bath at 40°C for 7 days. - Example 2: Left in a room with temperature controlled at 23°C ± 2°C for 28 days. Then, using the exact same procedure as in (1) above, multiple layers were laminated on a hot plate at 60°C using a rubber roll, and the resulting laminate was cured in an oven at 110°C for 1 hour, then at 170°C for 3 hours, cut into strips 3 mm wide x 33 mm long, and these were used as measurement samples after changes over time.

[0129] (Calculation of the rate of change of storage modulus over time) Each sample prepared in (1) and (2) above was mounted on a dynamic viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.), and the dynamic viscoelasticity of the sample was measured under the following conditions. From the measurement results, the storage modulus at 200°C was read, and the rate of change of storage modulus over time was determined from the samples used for measurement before and after the change over time, based on the following formula. The results are shown in Tables 1 and 2. Rate of change of storage modulus over time (%) = [(Storage modulus before change over time - Storage modulus after change over time) / Storage modulus before change over time] × 100 (Conditions) ・Measurement mode: Tensile ・Chuck distance: 20 mm ・Heating rate: 10°C / min (Example 1, Comparative Example 1, and Comparative Example 2), 3°C / min (Example 2) ・Frequency: 10 Hz ・Load: Automatic static load ・Measurement temperature: 35°C to 270°C

[0130]

[0131]

[0132] As shown in Table 1, when comparing Example 1, Comparative Example 1, and Comparative Example 2, which have similar amounts of thermally conductive particles, Example 1, which has a predetermined phenolic resin ((Ca) component) content of 100% by mass, showed a significantly suppressed rate of change in storage modulus over time compared to Comparative Example 1, which has a content of 50% by mass, and Comparative Example 2, which contains no (Ca) component. This indicates that a (Ca) component content of 50% by mass is insufficient, while a content of 70% by mass or more, especially 100% by mass, yields excellent results. Furthermore, as shown in Table 2, even in Example 2, where the thermally conductive particles were further increased in density (81% by mass) and different storage conditions were applied, the rate of change in storage modulus over time was kept sufficiently low. From these results, it was confirmed that the film-like adhesive of this disclosure, when highly densely packed with thermally conductive particles, can suppress the decrease in storage modulus over time at high temperatures after curing, even when stored at relatively low temperatures for a long period before curing.

[0133] 10...Adhesive layer, 10A...Film-type adhesive, 10a...Adhesive piece, 10ac...Cured adhesive piece, 12...Adhesive member, 20...Support film, 30, 30a...Adhesive layer, 40...Base layer, 50...Dicing tape, 60...Semiconductor chip with adhesive piece, 70...Wire, 72...Needle, 74...Suction collet, 80...Support member, 92...Sealing material layer, 94...Solder ball, 100...Dicing / die bonding integrated film, 200...Semiconductor device, W...Semiconductor wafer, Wa...Semiconductor chip.

Claims

1. A film-like adhesive containing thermally conductive particles, an epoxy resin, and a phenolic resin, wherein the phenolic resin contains a phenolic resin having a hydroxyl group equivalent of 185 g / eq or more, and the content of the phenolic resin having a hydroxyl group equivalent of 185 g / eq or more is 70% by mass or more based on the total amount of the phenolic resin.

2. A film-like adhesive containing thermally conductive particles, an epoxy resin, and a phenolic resin, wherein the phenolic resin includes a phenolic resin having a biphenyl skeleton, and the content of the phenolic resin having a biphenyl skeleton is 70% by mass or more based on the total amount of the phenolic resin.

3. The film-like adhesive according to claim 1, wherein the phenol resin having a hydroxyl group equivalent of 185 g / eq or more is a phenol resin having a biphenyl skeleton.

4. The film-like adhesive according to any one of claims 1 to 3, wherein the content of the thermally conductive particles is 60% by mass or more based on the total amount of the film-like adhesive.

5. The film-like adhesive according to any one of claims 1 to 3, further containing an elastomer.

6. The film-like adhesive according to any one of claims 1 to 3, wherein the epoxy resin comprises a liquid epoxy resin that is liquid at 30°C.

7. The film-like adhesive according to any one of claims 1 to 3, wherein the thermally conductive particles are metal particles.

8. A film-like adhesive according to any one of claims 1 to 3, wherein the thickness is 150 μm or less.

9. A dicing-die bonding integrated film comprising, in this order, a base layer, an adhesive layer, and an adhesive layer made of a film-like adhesive according to any one of claims 1 to 3.

10. A semiconductor device comprising: a semiconductor chip; a support member on which the semiconductor chip is mounted; and a cured film-like adhesive according to any one of claims 1 to 3, provided between the semiconductor chip and the support member to bond the semiconductor chip and the support member.

11. A method for manufacturing a semiconductor device, comprising the step of interposing a film-like adhesive according to any one of claims 1 to 3 between a semiconductor chip and a support member, and bonding the semiconductor chip and the support member together.

12. A method for manufacturing a semiconductor device, comprising: a step of attaching the adhesive layer of the dicing-die bonding integrated film described in claim 9 to a semiconductor wafer; a step of producing a plurality of individual semiconductor chips with adhesive pieces by dicing the semiconductor wafer to which the adhesive layer has been attached; and a step of bonding the semiconductor chips with adhesive pieces to a support member via the adhesive pieces.

Images