JP7600683B2 - Semiconductor device manufacturing method, film-like adhesive and its manufacturing method, and dicing/die bonding integrated film - Google Patents

Description

This disclosure relates to a method for manufacturing a semiconductor device, a film-like adhesive and its manufacturing method, and a dicing/die bonding integrated film.

Conventionally, semiconductor devices are manufactured through the following steps. First, a semiconductor wafer is attached to a dicing adhesive sheet, and in this state, the semiconductor wafer is diced into semiconductor chips (dicing step). Then, a pick-up step, a pressure bonding step, a die bonding step, and the like are performed. Patent Document 1 discloses an adhesive film (a dicing/die bonding integrated film) that has both the function of fixing the semiconductor wafer in the dicing step and the function of adhering the semiconductor chip to the substrate in the die bonding step. In the dicing step, the semiconductor wafer and the adhesive layer are diced into individual pieces, thereby obtaining semiconductor chips with adhesive pieces.

In recent years, devices known as power semiconductor devices that perform functions such as controlling electric power have become widespread. Power semiconductor devices tend to generate heat due to the current supplied to them, and so excellent heat dissipation is required. Patent Document 2 discloses a conductive film-like adhesive (film-like adhesive) and a dicing tape with a film-like adhesive (a dicing and die bonding integrated film) that have higher heat dissipation properties after curing than before curing.

JP 2008-218571 A JP 2016-103524 A

However, semiconductor devices manufactured using conventional film adhesives or integrated dicing and die bonding films do not have sufficient heat dissipation properties, and there is still room for improvement.

Therefore, the main objective of this disclosure is to provide a method for manufacturing a semiconductor device with excellent heat dissipation properties.

The inventors of the present disclosure conducted research to address the above-mentioned issues, and discovered that using a film-like adhesive containing a specific combination of silver particles as an adhesive member for bonding a semiconductor chip to a support member improved the heat dissipation properties of the resulting semiconductor device, leading to the completion of the present invention.

One aspect of the present disclosure relates to a method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device includes the steps of preparing a dicing/die bonding integrated film having, in this order, a base layer, a pressure sensitive adhesive layer, and an adhesive layer made of a film-like adhesive; attaching a semiconductor wafer to the adhesive layer of the dicing/die bonding integrated film; dicing the semiconductor wafer to which the adhesive layer is attached to produce a plurality of individualized semiconductor chips with adhesive pieces; and adhering the semiconductor chips with adhesive pieces to a support member via the adhesive pieces. The film-like adhesive contains first silver particles, second silver particles having an average particle size larger than the first silver particles, and a thermosetting resin component. According to this method for manufacturing a semiconductor device, the adhesive member forms a heat dissipation path and exhibits high thermal conductivity, and the resulting semiconductor device has excellent heat dissipation properties.

The average particle size of the first silver particles and the average particle size of the second silver particles may both be 0.01 to 10 μm. The average particle size of the second silver particles may be more than twice the average particle size of the first silver particles.

The total content of the first silver particles and the second silver particles may be 75 to 95 mass% based on the total amount of the film-like adhesive. Based on the total amount of the film-like adhesive, the mass ratio of the content of the second silver particles to the content of the first silver particles may be 3.1 times or more. Based on the total amount of the film-like adhesive, the mass ratio of the content of the second silver particles to the content of the first silver particles may be 76:24 to 84:16.

The thermal conductivity of the cured film adhesive may be 5.0 W/m·K or more.

The film adhesive may further contain an elastomer. The thermosetting resin component may contain an epoxy resin and a phenolic resin. The epoxy resin may contain an epoxy resin that is liquid at 25°C.

Another aspect of the present disclosure relates to a method for producing a film-like adhesive. The method for producing the film-like adhesive includes a step of mixing a raw material varnish containing first silver particles, second silver particles having an average particle size larger than the first silver particles, and an organic solvent to prepare an adhesive varnish containing the first silver particles, the second silver particles, an organic solvent, and a thermosetting resin component, and a step of forming a film-like adhesive using the adhesive varnish. By using the film-like adhesive obtained by such a production method, a semiconductor device with excellent heat dissipation properties can be produced.

Another aspect of the present disclosure relates to a film-like adhesive. The film-like adhesive contains first silver particles, second silver particles having an average particle size larger than the first silver particles, and a thermosetting resin component. By using such a film-like adhesive, a semiconductor device with excellent heat dissipation properties can be manufactured.

Another aspect of the present disclosure relates to a dicing/die bonding integrated film. The dicing/die bonding integrated film comprises, in this order, a base layer, a pressure-sensitive adhesive layer, and an adhesive layer made of the above-mentioned film-like adhesive. By using such a dicing/die bonding integrated film, a semiconductor device with excellent heat dissipation properties can be manufactured.

The present disclosure provides a method for manufacturing a semiconductor device with excellent heat dissipation. The present disclosure also provides a film-like adhesive capable of manufacturing a semiconductor device with excellent heat dissipation, a method for manufacturing the same, and an integrated dicing and die bonding film.

FIG. 1 is a schematic cross-sectional view showing one embodiment of a film-like adhesive. FIG. 2 is a schematic cross-sectional view showing one embodiment of a dicing/die bonding integrated film. 3A, 3B, 3C, 3D, 3E, and 3F are schematic cross-sectional views showing each step of a method for manufacturing a semiconductor device according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing one embodiment of a semiconductor device.

Below, an embodiment of the present disclosure will be described with reference to the drawings as appropriate. However, the present disclosure is not limited to the following embodiment. In the following embodiment, the components (including steps, etc.) are not essential unless specifically stated. The size of the components in each figure is conceptual, and the relative relationship of the size between the components is not limited to that shown in each figure.

In this specification, the numerical range indicated using "~" indicates a range including the numerical values described before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper limit or lower limit of a certain stage of the numerical range may be replaced with the upper limit or lower limit of the numerical range of another stage. In the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the examples. In addition, the upper limit and lower limit values described individually can be arbitrarily combined. In this specification, "(meth)acrylate" means at least one of acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl". In addition, "(poly)" means both the case with and without the "poly" prefix. In addition, "A or B" may include either A or B, or may include both. In addition, the materials exemplified below may be used alone or in combination of two or more types, unless otherwise specified. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of those multiple substances present in the composition, unless otherwise specified.

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

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

The film-like adhesive 10A contains first silver particles (hereinafter sometimes referred to as "component (A)"), second silver particles (hereinafter sometimes referred to as "component (B)") whose average particle size is larger than that of the first silver particles, and a thermosetting resin component (hereinafter sometimes referred to as "component (C)"). If necessary, it may further contain 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)"), etc.

Component (A): first silver particles, component (B): second silver particles The silver particles as components (A) and (B) are components for enhancing the heat dissipation in the film-like adhesive. Component (B) is a silver particle having an average particle size larger than that of component (A). The silver particles may be, for example, particles composed of silver (particles composed of silver alone) 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) and component (B) may be particles composed of silver.

The silver particles as components (A) and (B) are not particularly limited, but examples 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. Both the silver particles as components (A) and (B) may be silver particles produced by a reduction method.

In the liquid phase (wet) reduction method using a reducing agent, a surface treatment agent (lubricant) is usually added from the viewpoint of particle size control and prevention of aggregation and fusion, and the silver particles produced by the liquid phase (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 that have been 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 fatty 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.

The shape of the silver particles as components (A) and (B) is not particularly limited and may be, for example, flake-like, resin-like, spherical, etc., or may be spherical. When the silver particles are spherical, the surface roughness (Ra) of the film-like adhesive tends to be improved.

The average particle size of the silver particles as the (A) and (B) components may be 0.01 to 10 μm. When the average particle size of the silver particles is 0.01 μm or more, the adhesive varnish tends to have the following effects: viscosity increase can be prevented when it is produced; a desired amount of silver particles can be contained in the film-like adhesive; the wettability of the film-like adhesive to the adherend can be ensured to exhibit better adhesion. When the average particle size of the silver particles is 10 μm or less, the film formability is excellent, and the heat dissipation due to the addition of silver particles tends to be improved. In addition, by having the average particle size of the silver particles be 10 μm or less, the thickness of the film-like adhesive can be made thinner, and the semiconductor chips can be highly laminated, and the occurrence of cracks in the semiconductor chips due to the silver particles protruding from the film-like adhesive tends to be prevented. The average particle size of the silver particles as components (A) and (B) 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.

In this specification, the average particle size of the silver particles as components (A) and (B) means the particle size when the ratio (volume fraction) to the volume of the total silver particles is 50% (laser 50% particle size ( _D50 )). The average particle size ( _D50 ) can be determined by measuring a suspension of silver particles in water by a laser scattering method using a laser scattering type particle size measuring device (e.g., Microtrack).

The average particle size of the silver particles as component (A) may be, for example, 0.01 μm or more and 1 μm or less. The average particle size of the silver particles as component (A) may be 0.1 μm or more and 1 μm or less, or 0.5 μm or more and 1 μm or less.

The average particle size of the silver particles as component (B) may be more than 1 μm and not more than 10 μm. The average particle size of the silver particles as component (B) may be more than 1 μm and not more than 8.0 μm, more than 1 μm and not more than 7.0 μm, more than 1 μm and not more than 6.0 μm, more than 1 μm and not more than 5.0 μm, more than 1 μm and not more than 4.0 μm, or more than 1 μm and not more than 3.0 μm.

Component (B) is silver particles having an average particle size larger than component (A), and may be more than twice the average particle size of component (A). Component (B) may be, for example, 10 times or less, 8 times or less, 6 times or less, or 5 times or less the average particle size of component (A).

The total content of the (A) component and the (B) component may be 75 to 95% by mass based on the total amount of the film-like adhesive. When the total content of the (A) component and the (B) component is 75% by mass or more based on the total amount of the film-like adhesive, the thermal conductivity of the film-like adhesive can be further improved, and the heat dissipation of the semiconductor device tends to be further improved. The total content of the (A) component and the (B) component may be 78% by mass or more, 80% by mass or more, or 82% by mass or more based on the total amount of the film-like adhesive. When the total content of the (A) component and the (B) component is 95% by mass or less based on the total amount of the film-like adhesive, other components can be contained more sufficiently in the film-like adhesive, and when a dicing/die bonding integrated film is formed, the adhesion between the adhesive layer and the pressure-sensitive adhesive layer tends to be more sufficient. The total content of the (A) component and the (B) component may be 92% by mass or less, 90% by mass or less, less than 90% by mass, or 88% by mass or less based on the total amount of the film-like adhesive. The total content of the (A) component and the (B) component based on the total amount of solids in the adhesive varnish may be in the same range as above.

When the total amount of the film-like adhesive is used as a standard, the mass ratio of the content of the (B) component to the content of the (A) component (content of the (B) component/content of the (A) component) may be 3.1 times or more. When the mass ratio is 3.1 times or more, the adhesive strength and thermal conductivity of the film-like adhesive can be more effectively compatible. The mass ratio may be 3.2 times or more or 3.3 times or more. The upper limit of the mass ratio may be, for example, 6 times or less, 5 times or less, or 4 times or less. The mass ratio when the total amount of solids in the adhesive varnish is used as a standard may be the same as the above range.

Based on the total amount of the film-like adhesive, the mass ratio of the content of component (B) to the content of component (A) may be 76:24 to 84:16. When the mass ratio is in this range, the adhesive strength and thermal conductivity of the film-like adhesive can be more effectively compatible. The mass ratio may be 76:24 to 82:18 or 76:24 to 80:20. The mass ratio based on the total amount of solids in the adhesive varnish may be in the same range as above.

Component (C): Thermosetting Resin Component Component (C) may be, for example, a combination of a thermosetting resin (hereinafter sometimes referred to as "component (C1)") and a curing agent (hereinafter sometimes referred to as "component (C2)"). Component (C1) is a component that has the property of forming a three-dimensional bond between molecules and curing by heating or the like, and is a component that exhibits adhesive properties after curing. Component (C1) may be an epoxy resin. Component (C2) may be a phenolic resin that can be a curing agent for epoxy resin. Component (C) may contain an epoxy resin as component (C1) and a phenolic resin as component (C2).

(Epoxy resin)
The epoxy resin can be used without any 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. The epoxy resin may include an epoxy resin that is liquid at 25°C.

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, triphenol methane 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. These may be used alone or in combination of two or more.

The epoxy resin may contain an epoxy resin that is liquid at 25°C. By containing such an epoxy resin, the surface roughness (Ra) of the film-like adhesive tends to be improved. Examples of commercially available epoxy resins that are liquid at 25°C include EXA-830CRP (product name, manufactured by DIC Corporation) and YDF-8170C (product name, manufactured by Nippon Steel Chemical & Material Co., Ltd.).

The epoxy equivalent of the epoxy resin is not particularly limited, but may be 90 to 300 g/eq or 110 to 290 g/eq. When the epoxy equivalent of the epoxy resin is in such a range, it tends to be easier to ensure the fluidity of the adhesive varnish when forming the film-like adhesive while maintaining the bulk strength of the film-like adhesive.

The content of component (C1) may be 0.1% by mass or more, 1% by mass or more, 2% by mass or more, or 3% by mass or more based on the total amount of the film-like adhesive, and may be 15% by mass or less, 12% by mass or less, 10% by mass or less, 8% by mass or less, or 6% by mass or less. The content of component (C1) based on the total amount of solids in the adhesive varnish may be in the same range as above.

When the epoxy resin is liquid at 25°C as the component (C1), the mass ratio of the epoxy resin to the total amount of the component (C1) (mass of the epoxy resin/total mass of the component (C1)) may be 10-100%, 40-100%, 60%-100%, or 80%-100% in percentage. The mass ratio of the epoxy resin to the total amount of the component (C1) in the adhesive varnish may be the same as the above range. When the epoxy resin is liquid at 25°C as the component (C1), the content of the epoxy resin may be 0.1% by mass or more, 1% by mass or more, 2% by mass or more, or 3% by mass or more based on the total amount of the film-like adhesive, and may be 15% by mass or less, 12% by mass or less, 10% by mass or less, 8% by mass or less, or 6% by mass or less. The content of the epoxy resin based on the total amount of solids in the adhesive varnish may be the same as the above range.

(Phenol resin)
The phenolic resin can be used without any particular limitation as long as it has a phenolic hydroxyl group in the molecule. Examples of the phenolic resin include novolac-type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, etc. and/or naphthols such as α-naphthol, β-naphthol, dihydroxynaphthalene, etc. with a compound having an aldehyde group such as formaldehyde under an acidic catalyst, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, phenol aralkyl resins synthesized from phenols such as phenol and/or naphthols and dimethoxyparaxylene or bis(methoxymethyl)biphenyl, naphthol aralkyl resins, biphenyl aralkyl-type phenolic resins, phenyl aralkyl-type phenolic resins, etc. These may be used alone or in combination of two or more.

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. If the hydroxyl equivalent of the phenolic resin is 40 g/eq or more, the storage modulus of the film tends to be improved, and if it is 300 g/eq or less, it is possible to prevent defects due to the generation of foaming, outgassing, etc.

The ratio of the epoxy equivalent of the epoxy resin (C1) to the hydroxyl equivalent of the phenolic resin (C2) (epoxy equivalent of the epoxy resin (C1)/hydroxyl equivalent of the phenolic resin (C2)) 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. If the equivalent ratio is 0.30/0.70 or more, more sufficient curability tends to be obtained. If the equivalent ratio is 0.70/0.30 or less, it is possible to prevent the viscosity from becoming too high, and more sufficient fluidity can be obtained.

The content of the (C2) component may be 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, or 2% by mass or more based on the total amount of the film-like adhesive, and may be 15% by mass or less, 12% by mass or less, 10% by mass or less, 8% by mass or less, or 6% by mass or less. The content of the (C2) component based on the total amount of solids in the adhesive varnish may be in the same range as above.

The content of component (C) (the total content of components (C1) and (C2)) may be 0.1% by mass or more, 1% by mass or more, 3% by mass or more, or 5% by mass or more based on the total amount of the film-like adhesive, and may be 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less. The content of component (C) based on the total amount of solids in the adhesive varnish may be in the same range as above.

(D) component: elastomer Examples of the (D) component include polyimide resin, acrylic resin, urethane resin, polyphenylene ether resin, polyetherimide resin, phenoxy resin, modified polyphenylene ether resin, etc. The (D) component may be any of these resins having a crosslinkable functional group, or may be an acrylic resin having a crosslinkable functional group. Here, the acrylic resin means a (meth)acrylic (co)polymer containing a structural unit derived from a (meth)acrylate ((meth)acrylic acid ester). The acrylic resin may be a (meth)acrylic (co)polymer containing a structural unit derived from a (meth)acrylate having a crosslinkable functional group such as an epoxy group, an alcoholic or phenolic hydroxyl group, or a carboxy group. The acrylic resin may also be an acrylic rubber such as a copolymer of a (meth)acrylate and an acrylonitrile. These elastomers may be used alone or in combination of two or more.

Commercially available acrylic resins include, for example, SG-P3, 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).

The glass transition temperature (Tg) of the elastomer as component (D) may be -50 to 50°C or -30 to 20°C. If the Tg is -50°C or higher, the tackiness of the film-like adhesive will be reduced, and the handling properties will tend to be improved. If the Tg is 50°C or lower, the fluidity of the adhesive varnish when forming the film-like adhesive will tend to be more adequately 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).

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 property tends to be superior. 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 superior. Here, the Mw of the elastomer as component (D) means a value measured by gel permeation chromatography (GPC) and converted using a calibration curve with standard polystyrene.

The Mw of the elastomer as component (D) may be measured using, for example, the following equipment and conditions:
Pump: L-6000 (manufactured by Hitachi, Ltd.)
Column: A column in which 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) are connected in this order. Eluent: Tetrahydrofuran (hereinafter referred to as "THF")
Sample: 120 mg of sample dissolved in 5 mL of THF Flow rate: 1.75 mL/min

The content of component (D) may be 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 2% by mass or more, or 3% by mass or more based on the total amount of the film-like adhesive, and may be 15% by mass or less, 12% by mass or less, 10% by mass or less, 8% by mass or less, or 6% by mass or less. The content of component (D) based on the total amount of solids in the adhesive varnish may be in the same range as above.

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, 3-(2-aminoethyl)aminopropyltrimethoxysilane, etc. These may be used alone or in combination of two or more.

Component (F): Curing Accelerator Examples of the component (F) include imidazoles and their derivatives, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used alone or in combination of two or more. Among these, the component (F) may be imidazoles and their derivatives from the viewpoint of reactivity.

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

The film adhesive may further contain other components. Examples of other components include pigments, ion scavengers, antioxidants, etc.

The total content of the (E), (F), and other components may be 0.005 to 10% by mass based on the total mass of the film-like adhesive. The total content of the (E), (F), and other components based on the total solid content of the adhesive varnish may be in the same range as above.

[Method of manufacturing film-like adhesive]
The film-like adhesive 10A shown in Fig. 1 can be obtained, for example, by a manufacturing method including a step (mixing step) of mixing a raw material varnish containing the (A) component, the (B) component, and an organic solvent to prepare an adhesive varnish containing the (A) component, the (B) component, an organic solvent, and the (C) component, and a step (forming step) of forming a film-like adhesive using the adhesive varnish. The adhesive varnish may further contain the (D), (E), (F) component, and other components, etc., as necessary.

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

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 may be used alone or in combination of two or more. Among 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% by mass based on the total mass of the raw varnish.

The raw varnish can be obtained, for example, by adding each component to a container used with a mixer. In this case, the order of addition of each component is not particularly limited and can be set appropriately according to the properties of each component.

Mixing can be performed by appropriately combining ordinary mixers such as a homodisper, a three-one motor, a mixing rotor, a planetary rotor, or a mortar 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 the adhesive varnish. When a homodisper is used for mixing, the rotation speed of the homodisper may be 4000 rpm or more.

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 heated by a heating device or the like as necessary. According to the study by the inventors of the present disclosure, it has been found that when the mixing temperature in the mixing step is 50°C or higher, for example, when silver particles (preferably silver particles produced by a reduction method) are used, the resulting film-like adhesive may contain a sintered body of silver particles in the C-stage state. Such a phenomenon is more pronounced when silver particles produced by a reduction method are used as the (A) and (B) components. The reason for such a phenomenon is not necessarily clear, but the inventors of the present disclosure consider it as follows. The silver particles (produced by a liquid phase (wet) reduction method using a reducing agent) as the (A) and (B) components are usually coated on the surface with a surface treatment agent (lubricant). Here, it is presumed that when the mixing temperature in the mixing step is 50°C or higher, the surface treatment agent covering the silver particles dissociates and the silver surface (in a reduced state) is easily exposed. 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 for hardening, the silver particles are likely to sinter together to form a sintered body of silver particles. As a result, it is believed that the film-like adhesive contains a sintered body of silver particles in the C-stage state. Silver particles produced by the atomization method are covered with a silver oxide film on the surface of the silver particles due to the characteristics of the production method. According to the study by the inventors of the present disclosure, it has been 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 obtained film-like adhesive is unlikely to contain a sintered body of silver particles in the 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 of 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.

Component (C), component (D), component (E), component (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 material varnish before the mixing step, or added to the adhesive varnish after the mixing step. Component (E) and component (F) are preferably added to the adhesive varnish after the mixing step. When added to the adhesive varnish after the mixing step, they may be mixed after the addition under temperature conditions of less than 50°C (for example, room temperature (25°C)). In this case, the conditions may be room temperature (25°C) for 0.1 to 48 hours.

In this manner, an adhesive varnish containing component (A), component (B), an organic solvent, and component (C) can be prepared. After preparation, the adhesive varnish may be subjected to vacuum degassing or the like to remove air bubbles therein.

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

(Forming process)
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.

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, curtain coating, etc.

After the adhesive varnish is applied to the support film, the organic solvent may be dried by heating, if necessary. There are no particular limitations on the conditions for drying by heating, so long as the organic solvent used is sufficiently volatilized. For example, the drying temperature may be 50 to 200°C, and the drying time may be 0.1 to 30 minutes. Drying by heating may be performed in stages at different drying temperatures or times.

In this manner, the film-like adhesive 10A can be obtained. The thickness of the film-like adhesive 10A can be adjusted appropriately according to 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, or 30 μm or less.

In the C-stage state, the thermal conductivity (35°C) of the film-like adhesive 10A may be 5.0 W/m·K or more. When the thermal conductivity is 5.0 W/m·K or more, the heat dissipation of the semiconductor device tends to be better. The thermal conductivity may be 5.2 W/m·K or more, 5.4 W/m·K or more, 5.6 W/m·K or more, 5.8 W/m·K or more, or 6.0 W/m·K or more. The upper limit of the thermal conductivity (35°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, the thermal conductivity means a value calculated by the method described in the examples. In addition, the heating conditions for curing the film-like adhesive 10A to the C-stage state may be, for example, a heating temperature of 110°C for a heating time of 1 hour, and then a heating temperature of 170°C for a heating time of 3 hours.

[Dicing/Die Bonding Integrated Film and Its Manufacturing Method]
2 is a schematic cross-sectional view showing one embodiment of a dicing/die bonding integrated film. The dicing/die bonding integrated film 100 shown in FIG. 2 includes a base layer 40, a pressure-sensitive adhesive layer 30, and an adhesive layer 10 made of a film-like adhesive 10A, in this order. The dicing/die bonding integrated film 100 can also be said to include a dicing tape 50 including a base layer 40 and a pressure-sensitive adhesive layer 30 provided on the base layer 40, and an adhesive layer 10 provided on the pressure-sensitive adhesive layer 30 of the dicing tape 50. The dicing/die bonding integrated film 100 may be in the form of a film, a sheet, a tape, or the like. The dicing/die bonding integrated film 100 may include a support film 20 on the surface of the adhesive layer 10 opposite to the pressure-sensitive adhesive layer 30.

The base layer 40 in the dicing tape 50 may be, for example, a plastic film such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, or a polyimide film. In addition, the base layer 40 may be subjected to a surface treatment such as a primer coating, a UV treatment, a corona discharge treatment, a polishing treatment, or an etching treatment, as necessary.

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

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 standpoint of economy and ease of handling of the film.

The dicing/die bonding integrated film 100 shown in FIG. 2 can be obtained by a manufacturing method including a step of preparing a film-like adhesive 10A and a dicing tape 50 including a base layer 40 and a pressure-sensitive adhesive layer 30 provided on the base layer 40, and a step of bonding the film-like adhesive 10A to the pressure-sensitive adhesive layer 30 of the dicing tape 50. A known method can be used as a method for bonding the film-like adhesive 10A to the pressure-sensitive adhesive layer 30 of the dicing tape 50.

[Method of Manufacturing Semiconductor Device]
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 cross-sectional views showing each step. The method for manufacturing a semiconductor device includes a step of attaching a semiconductor wafer W to the adhesive layer 10 of the dicing-die bonding integrated film 100 (wafer lamination step, see Figures 3(a) and 3(b)), a step of dicing the semiconductor wafer W to which the adhesive layer 10 is attached to produce a plurality of individualized semiconductor chips 60 with adhesive pieces (dicing step, see Figure 3(c)), and a step of attaching 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 manufacturing method of the semiconductor device may further include, between the dicing step and the semiconductor chip bonding step, a step of irradiating the adhesive layer 30 (through the base layer 40) with ultraviolet light (ultraviolet light 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 is attached from the adhesive layer 30a (pick-up step, see Figure 3(e)), and a step of thermally curing the adhesive piece 10a in the semiconductor chip 60 with adhesive piece bonded to the support member 80 (thermal curing step), as necessary.

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

Semiconductor wafers W include, for example, single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

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

<Ultraviolet ray irradiation process>
When the adhesive layer 30 is an ultraviolet-curing adhesive layer, the method for manufacturing a semiconductor device may include an ultraviolet irradiation step. In this step, the adhesive layer 30 is irradiated with ultraviolet light (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 may be such that the illuminance and the dose are in the ranges of 30 to 240 mW/ ^cm2 and 50 to 500 mJ/ ^cm2 , respectively.

<Pickup process>
In this process, the adhesive piece-attached semiconductor chips 60 are separated from each other by expanding the base layer 40, and the adhesive piece-attached semiconductor chips 60 pushed up by the needle 72 from the base layer 40 side are sucked by the suction collet 74 and picked up from the adhesive layer 30a (see FIG. 3(e)). The adhesive piece-attached semiconductor chips 60 have a semiconductor chip Wa and an adhesive piece 10a. The semiconductor chip Wa is an individualized semiconductor wafer W, and the adhesive piece 10a is an individualized adhesive layer 10. The adhesive layer 30a is an individualized adhesive layer 30. The adhesive layer 30a may remain on the base layer 40 after the adhesive piece-attached semiconductor chips 60 are picked up. In this process, it is not necessarily necessary to expand the base layer 40, but by expanding the base layer 40, the pick-up property can be further improved.

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

<Semiconductor chip bonding process>
In this step, 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 pieces may be bonded to the support member 80.

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

<Thermal curing process>
In this step, the adhesive piece 10a in the semiconductor chip 60 with adhesive piece attached to the support member 80 is thermally cured. By (further) thermally curing the adhesive piece 10a or the cured product 10ac of the adhesive piece that bonds the semiconductor chip Wa and the support member 80, it is possible to bond and fix more firmly. In addition, when the (A) component and the (B) component are silver particles produced by a reduction method, by (further) thermally curing the adhesive piece 10a or the cured product 10ac of the adhesive piece, it tends to be easier to obtain a sintered body of silver particles. When performing thermal curing, pressure may be applied at the same time to harden. The heating temperature in this step 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, 90 to 190°C, or 120 to 180°C. The heating time may be 30 minutes to 5 hours, 1 to 3 hours, or 2 to 3 hours. The temperature or pressure may be changed stepwise.

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

The manufacturing method of the semiconductor device may include, as necessary, a process (wire bonding process) of electrically connecting the tip of the terminal portion (inner lead) of the support member to the electrode pad on the semiconductor element with a bonding wire. For example, a gold wire, an aluminum wire, a copper wire, etc., is used as the bonding wire. The temperature when performing the 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 combining ultrasonic vibration energy and compression energy by applied pressure while heated within the above temperature range.

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

The method for manufacturing a semiconductor device may include a process (post-curing process) for completely curing the encapsulating resin that is not fully cured in the encapsulating process, if necessary. Even if the adhesive piece is not thermally cured in the encapsulating process, the adhesive piece can be thermally cured in this process together with the encapsulating resin, thereby enabling adhesion and fixation. The heating temperature in this process can be set appropriately depending on the type of encapsulating resin, and may be within the range of 165 to 185°C, for example, and the heating time may be about 0.5 to 8 hours.

The method for manufacturing a semiconductor device may, if necessary, 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 by hot air or the like, and soldered. Examples of heating methods include hot air reflow and infrared reflow. The heating method may be to heat the entire surface or to heat localized areas. The heating temperature may be, for example, within the range of 240 to 280°C.

[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 product of a film-like adhesive containing a sintered body of silver particles (cured product 10ac of an adhesive piece). The connection terminal (not shown) of the semiconductor chip Wa may be electrically connected to an external connection terminal (not shown) via a wire 70. The semiconductor chip Wa may be sealed by a sealing material 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 with an external board (motherboard) (not shown).

The semiconductor chip Wa (semiconductor element) 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 in which a substrate such as glass nonwoven fabric is impregnated and hardened with plastics such as polyimide resin and epoxy resin; and ceramics such as alumina.

The semiconductor device 200 has excellent heat dissipation properties because it is provided with the above-mentioned cured film-like adhesive as an adhesive member.

The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to these.

(Example 1-1 and Comparative Example 1-1)
<Preparation of adhesive varnish>
Cyclohexanone was added as an organic solvent to the components (A), (B), (C), and (D) in the symbols and composition ratios (unit: parts by mass) shown in Table 1 to prepare raw varnishes. The raw varnishes were stirred for 20 minutes at 4000 rpm under a mixing temperature condition of 30°C using a homodisper (T.K. HOMO MIXER MARK II, manufactured by Tajima Chemical Machinery Co., Ltd.) to obtain adhesive varnishes. Next, components (E) and (F) were added to the adhesive varnish, and the mixture was stirred overnight at 250 rpm using a three-one motor. In this way, adhesive varnishes with a solid content of 61% by mass of Example 1-1 and Comparative Example 1-1 were prepared.

The symbols for each component in Table 1 and Table 2 below have the following meanings:

Component (A): first silver particles (A-1) AG-2-1C (product name, manufactured by Dowa Electronics Co., Ltd., shape: spherical, average particle size (laser 50% particle size (D ₅₀ )): 0.7 μm)

Component (B): second silver particles (B-1) AG-5-1F (product name, manufactured by Dowa Electronics Co., Ltd., shape: spherical, average particle size (laser 50% particle size (D ₅₀ )): 2.9 μm)
(B-2) AG-4-1F (product name, manufactured by Dowa Electronics Co., Ltd., shape: spherical, average particle size (laser 50% particle size (D ₅₀ )): 2.5 μm)
(B-3) AG-3-1F (product name, manufactured by Dowa Electronics Co., Ltd., shape: spherical, average particle size (laser 50% particle size (D ₅₀ )): 1.5 μm)
(B-4) Ag-HWQ (product name, Fukuda Metal Foil and Powder Co., Ltd., silver particles produced by atomization method, shape: spherical, average particle size (laser 50% particle size (D ₅₀ )): 1.5 μm)

Component (C): Thermosetting resin component Component (C1): Thermosetting resin (C1-1) EXA-830CRP (trade name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 159 g/eq, liquid at 25°C)
Component (C2): Curing agent (C2-1) MEH-7800M (product name, manufactured by Meiwa Kasei Co., Ltd., phenolic resin, hydroxyl group equivalent: 175 g/eq)

Component (D): Elastomer (D-1) SG-P3 (product name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight average molecular weight: 800,000, Tg: -7°C)

Component (E): Coupling agent (E-1) A-1160 (product name, manufactured by GE Toshiba Silicones Co., Ltd., γ-ureidopropyltriethoxysilane)

Component (F): Curing accelerator (F-1) 2PZ-CN (trade name, manufactured by Shikoku Chemical Industry Co., Ltd., 1-cyanoethyl-2-phenylimidazole)

<Preparation of film adhesive>
Film-like adhesives were prepared using the adhesive varnishes of Example 1-1 and Comparative Example 1-1. Each adhesive varnish was vacuum degassed, and the adhesive varnish was then applied to a polyethylene terephthalate (PET) film (thickness: 38 μm) that had been subjected to a release treatment, which was a support film. The applied adhesive varnish was heated and dried in two stages, at 90° C. for 5 minutes and then at 130° C. for 5 minutes, to obtain film-like adhesives of Example 1-1 and Comparative Example 1-1 in a B-stage state and having a thickness of 20 μm on the support film.

<Measurement of thermal conductivity>
(Preparation of film for measuring thermal conductivity)
A laminated film having a thickness of 100 μm or more was prepared by laminating the film-like adhesives of Example 1-1 and Comparative Example 1-1 with a rubber roll. The laminated film obtained was covered on both sides with PET films and heat-cured 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.

(Measurement of thermal conductivity)
The thermal conductivity λ of the film for measuring thermal conductivity was calculated by the following formula. The results are shown in Table 1.
Thermal conductivity λ (W/m・K) = Thermal diffusivity α (mm ² /s) × Specific heat Cp (J/g・K) × Specific gravity ρ (g/cm ³ )
The thermal diffusivity α, the specific heat Cp, and the specific gravity ρ were measured by the following methods: A high thermal conductivity λ means that the semiconductor device has better heat dissipation properties.

(Measurement of thermal diffusivity α)
The obtained thermal conductivity measurement film was cut into 10 mm squares. Blackguard spray (FC-153, Fine Chemical Japan Co., Ltd.) was applied to both sides of the cut thermal conductivity measurement film to prepare a measurement sample. A flash analyzer (LFA467 HyperFlash, Netsch Japan Co., Ltd.) was used to measure the thermal diffusivity α at 35°C.

(Measurement of specific heat Cp)
The specific heat Cp at 35° C. was calculated by measuring using a differential scanning calorimeter (DSC) (high sensitivity differential scanning calorimeter DSC8231 (manufactured by Rigaku Corporation)) at a temperature rise rate of 10° C./min at temperatures of 25° C. to 70° C.

(Measurement of specific gravity ρ)
The measurement was performed by the Archimedes method using an electronic specific gravity meter (EW-300SG, manufactured by Alpha Mirage Co., Ltd.).

As shown in Table 1, the film adhesive of Example 1-1, which used a specified combination of silver particles, was superior in terms of thermal conductivity to the film adhesive of Comparative Example 1-1, which used a non-specified combination of silver particles.

(Examples 2-1 to 2-5 and Comparative Example 2-1)
<Preparation of adhesive varnish>
Cyclohexanone was added as an organic solvent to the components (A), (B), (C), and (D) in the symbols and composition ratios (unit: parts by mass) shown in Table 2 to prepare raw varnishes. The raw varnishes were stirred for 20 minutes at 4000 rpm under a mixing temperature condition of 70°C using a homodisper (T.K. HOMO MIXER MARK II, manufactured by Tajima Chemical Machinery Co., Ltd.) to obtain adhesive varnishes. The adhesive varnishes were then left to stand until they reached 20 to 30°C, after which the 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 with a solid content of 61% by mass for Examples 2-1 to 2-5 and Comparative Example 2-1 were prepared.

<Preparation of film adhesive>
The film-like adhesives of Examples 2-1 to 2-5 and Comparative Example 2-1 were prepared in the same manner as for the film-like adhesives of Example 1-1 and Comparative Example 1-1, except that the adhesive varnishes of Examples 2-1 to 2-5 and Comparative Example 2-1 were used instead of the adhesive varnishes of Example 1-1 and Comparative Example 1-1.

<Measurement of thermal conductivity>
The thermal conductivity of the film-like adhesives of Examples 2-1 to 2-5 and Comparative Example 2-1 was measured in the same manner as in the measurement of the thermal conductivity of the film-like adhesives of Example 1-1 and Comparative Example 1-1, except that the film-like adhesives of Examples 2-1 to 2-5 and Comparative Example 2-1 were used instead of the film-like adhesives of Example 1-1 and Comparative Example 1-1. The results are shown in Table 2.

As shown in Table 2, the film-like adhesives of Examples 2-1 to 2-5, which used a specified combination of silver particles, were superior in terms of thermal conductivity compared to the film-like adhesive of Comparative Example 2-1, which used a non-specified combination of silver particles. In addition, compared to the results shown in Table 1, it was found that the thermal conductivity of the resulting film-like adhesive was improved by increasing the mixing temperature.

These results confirm that the film-like adhesive of the present disclosure has high thermal conductivity and high heat dissipation properties in the C-stage state. In a semiconductor device, the cured product of the film-like adhesive constitutes the adhesive member of the semiconductor device. Therefore, when the film-like adhesive of the present disclosure is applied to a semiconductor device, the cured product of the film-like adhesive of the present disclosure becomes the adhesive member of the semiconductor device, and the resulting semiconductor device is expected to have excellent heat dissipation properties.

10...adhesive layer, 10A...film-like adhesive, 10a...adhesive piece, 10ac...cured adhesive piece, 12...adhesive member, 20...support film, 30, 30a...adhesive layer, 40...substrate 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 and die bonding integrated film, 200...semiconductor device, W...semiconductor wafer, Wa...semiconductor chip.

Claims (10)

A step of preparing a dicing/die bonding integrated film including a base layer, a pressure-sensitive adhesive layer, and an adhesive layer made of a film-like adhesive in this order;
attaching a semiconductor wafer to the adhesive layer of the dicing and die bonding integrated film;
dicing the semiconductor wafer to which the adhesive layer is attached to produce a plurality of individual adhesive-attached semiconductor chips;
a step of adhering the semiconductor chip with the adhesive piece to a support member via the adhesive piece;
Equipped with
the film-like adhesive contains first silver particles, second silver particles having an average particle size larger than that of the first silver particles, and a thermosetting resin component;
the total content of the first silver particles and the second silver particles is 75 to 95 mass% based on the total amount of the film-like adhesive,
the mass ratio of the content of the second silver particles to the content of the first silver particles is 3.1 times or more based on the total amount of the film-like adhesive;
A method for manufacturing a semiconductor device, wherein the average particle size of the second silver particles is more than twice but not more than 10 times the average particle size of the first silver particles . The method for manufacturing a semiconductor device according to claim 1, wherein the average particle size of the first silver particles and the average particle size of the second silver particles are 0.01 to 10 μm. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the mass ratio of the content of the second silver particles to the content of the first silver particles is 76:24 to 84:16 based on the total amount of the film-like adhesive. The method for manufacturing a semiconductor device according to any one of claims 1 to 3 , wherein the thermal conductivity of the cured product of the film-like adhesive is 5.0 W/m·K or more. The method for manufacturing a semiconductor device according to claim 1 , wherein the film-like adhesive further contains an elastomer. 6. The method for manufacturing a semiconductor device according to claim 1 , wherein the thermosetting resin component includes an epoxy resin and a phenolic resin. The method for manufacturing a semiconductor device according to claim 6 , wherein the epoxy resin contains an epoxy resin that is liquid at 25°C. a step of mixing a raw material varnish containing first silver particles, second silver particles having an average particle size larger than that of the first silver particles, and an organic solvent to prepare an adhesive varnish containing the first silver particles, the second silver particles, the organic solvent, and a thermosetting resin component;
forming a film-like adhesive using the adhesive varnish;
Equipped with
the total content of the first silver particles and the second silver particles is 75 to 95 mass% based on the total amount of the film-like adhesive,
the mass ratio of the content of the second silver particles to the content of the first silver particles is 3.1 times or more based on the total amount of the film-like adhesive,
A method for producing a film-like adhesive , wherein the average particle size of the second silver particles is more than twice but not more than 10 times the average particle size of the first silver particles . The electrochemical ink comprises first silver particles, second silver particles having an average particle size larger than that of the first silver particles, and a thermosetting resin component,
the total content of the first silver particles and the second silver particles is 75 to 95 mass% based on the total amount of the film-like adhesive,
the mass ratio of the content of the second silver particles to the content of the first silver particles is 3.1 times or more based on the total amount of the film-like adhesive,
A film-like adhesive, wherein the average particle size of the second silver particles is more than twice but not more than 10 times the average particle size of the first silver particles . 10. An integrated dicing and die bonding film comprising, in this order, a base layer, a pressure-sensitive adhesive layer, and an adhesive layer made of the film-like adhesive according to claim 9 .

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