Resin composition for encapsulation and semiconductor device

Abstract

To provide a resin composition for encapsulation that enables superior continuous moldability at a higher level.SOLUTION: A resin composition for encapsulation according to the present invention comprises: (A) an epoxy resin, (B) a phenolic curing agent, (C) an inorganic filler, and (D) a butadiene-acrylonitrile copolymer, and is configured to meet the following condition (i): Condition (i): Using a transfer molding machine, the resin composition for encapsulation is injected into a mold containing a chromium-plated copper plate, at a mold temperature of 175°C, and is cured by heating at 175°C for 300 seconds. The die shear strength (at a rate of 300 μm / sec and temperature of 25°C) between the resulting cured product of the resin composition for encapsulation and the copper plate is 7.0 N / mm2 or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an encapsulating resin composition and a semiconductor device. [Background technology]

[0002] In recent market trends toward smaller, lighter, and more powerful electronic devices, the integration of semiconductor elements has progressed year by year, and the surface mounting of semiconductor devices has been promoted. In addition, new area-mounted semiconductor devices have been developed, and semiconductor devices with conventional structures are being replaced by these. Accordingly, the requirements for the performance of encapsulating resin compositions used in the manufacturing process of semiconductor devices have become more diverse and sophisticated, and various encapsulating resin compositions have been researched and developed accordingly.

[0003] For example, Patent Document 1 discloses that, from the viewpoint of improving the adhesion of an encapsulating resin composition for semiconductor elements to metals and the resistance to high-temperature reflow during mounting, the encapsulating resin composition contains, as essential components, an epoxy resin containing an epoxy compound of a predetermined structure, a phenolic curing agent, an inorganic filler, a hollow structural body made of at least one material selected from an organic material and a silicone material, and a curing accelerator, and preferably further contains a butadiene-acrylonitrile copolymer or a triazine phenol resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-33514 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have focused on the problem of problems occurring in the encapsulation process of semiconductor devices, resulting in reduced productivity, and have found that when continuous molding is performed using a conventional encapsulating resin composition as disclosed in Patent Document 1, cracks occur in parts of the mold for the encapsulating resin composition, unfilled areas occur in the mold, and so on, resulting in reduced continuous moldability. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the problems of cracks and non-filling that occur when continuous molding is performed, and have found that even among encapsulating resin compositions containing an epoxy resin, a phenolic curing agent, an inorganic filler, and a butadiene-acrylonitrile copolymer, some have good continuous moldability and some do not. Therefore, the inventors have found that controlling the die shear strength of the cured encapsulating resin composition against chromium is an effective requirement for distinguishing between the two, and have embodied this as condition I to complete the present invention.

[0007] According to the present invention, the following encapsulating resin composition and related techniques can be provided.

[0008] [1] (A) an epoxy resin; (B) a phenol-based curing agent; (C) an inorganic filler; (D) butadiene-acrylonitrile copolymer, The encapsulating resin composition is configured to satisfy the following condition i: Condition i: Using a transfer molding machine, the encapsulating resin composition is injected into a mold in which a copper plate with a chrome-plated surface is placed at a mold temperature of 175° C., and cured by heating at 175° C. for 300 seconds. The die shear strength (speed 300 μm / sec, temperature 25° C.) between the obtained cured product of the encapsulating resin composition and the chrome-plated surface of the copper plate was 7.0 N / mm 2 The following is the result. [2] The encapsulating resin composition according to [1], (D) An encapsulating resin composition having a butadiene-acrylonitrile copolymer content of 0.01 to 2 mass % based on the total amount of the encapsulating resin composition. [3] The encapsulating resin composition according to [1] or [2], (D) An encapsulating resin composition, wherein the butadiene-acrylonitrile copolymer is represented by the following formula (1): [ka] (In formula (1), x and y are both positive numbers less than 1 and satisfy x+y=1.) [4] The encapsulating resin composition according to [3], An encapsulating resin composition, wherein in formula (1), y is 0.05 or more and 0.24 or less. [5] The encapsulating resin composition according to any one of [1] to [4], (A) An encapsulating resin composition comprising one or more epoxy resins selected from the group consisting of crystalline epoxy resins, novolac-type epoxy resins, polyfunctional epoxy resins, phenol aralkyl-type epoxy resins, naphthol-type epoxy resins, triazine nucleus-containing epoxy resins, and bridged cyclic hydrocarbon compound-modified phenol-type epoxy resins. [6] The encapsulating resin composition according to any one of [1] to [5], (B) An encapsulating resin composition, wherein the phenol-based curing agent comprises one or more selected from the group consisting of novolac-type phenolic resins, polyfunctional phenolic resins, modified phenolic resins, aralkyl-type phenolic resins, and bisphenol compounds. [7] The encapsulating resin composition according to any one of [1] to [6], (E) The encapsulating resin composition further comprising a curing accelerator. [8] The encapsulating resin composition according to any one of [1] to [7], (F) An encapsulating resin composition further comprising a silicone oil. [9] The encapsulating resin composition according to any one of [1] to [8], An encapsulating resin composition used for encapsulating a semiconductor element.

[10] A semiconductor device, comprising a semiconductor element encapsulated with the encapsulating resin composition according to any one of [1] to [9]. Effect of the Invention

[0009] The encapsulating resin composition of the present invention can provide excellent continuous moldability at a higher level. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a configuration of a semiconductor device according to an embodiment of the present invention. [Diagram 2] 11 is a cross-sectional view showing a configuration of a modified example of the semiconductor device in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In this specification, the expression "a to b" in the description of a numerical range means from a to b, unless otherwise specified. For example, "1 to 5 mass%" means "1 mass% to 5 mass%". Furthermore, the lower limit and upper limit of a numerical range can be arbitrarily combined with the lower limit and upper limit of another numerical range.

[0012] Unless otherwise specified, each of the components and materials exemplified in this specification may be used alone or in combination of two or more kinds.

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In order to avoid complexity, when there are multiple identical components in the same drawing, only one of them may be marked with a symbol, and not all of them may be marked with a symbol. All drawings are for illustrative purposes only. The shape and dimensional ratio of each component in the drawings do not necessarily correspond to the actual product.

[0014] <Sealing resin composition> The encapsulating resin composition of the present embodiment contains (A) an epoxy resin, (B) a phenol-based curing agent, (C) an inorganic filler, and (D) a butadiene-acrylonitrile copolymer, and is configured to satisfy the following condition i, thereby further improving the continuous moldability.

[0015] Condition i: Using a transfer molding machine, the encapsulating resin composition is injected into a mold in which a copper plate with a chrome-plated surface is placed at a mold temperature of 175°C, and cured by heating at 175°C for 300 seconds. The die shear strength (speed 300 μm / sec, temperature 25°C) between the obtained cured product of the encapsulating resin composition and the chrome-plated surface of the copper plate is 7.0 N / mm 2 The following is the result.

[0016] Although the details of the mechanism by which the encapsulating resin composition of the present embodiment can obtain the above-mentioned effects by satisfying condition i are not clear, it is presumed as follows. The die shear strength of condition i is intended to be the adhesive strength between the cured product of the encapsulating resin composition and the mold. Therefore, by controlling the die shear strength, it is possible to maintain good releasability from the mold, and it is considered that it is possible to suppress the occurrence of cracks in the cured product of the encapsulating resin composition and the occurrence of unfilled areas in the mold even when continuously molded. Furthermore, as one of the techniques for improving the releasability from the mold, it is known that the surface of the mold is plated with chromium or the like to improve the releasability. Therefore, in the encapsulating resin composition of this embodiment, by controlling the die shear strength against chromium plating, the releasability can be controlled at a higher level, and the continuous moldability can be effectively improved.

[0017] In condition i, the copper plate with a chromium-plated surface is a test piece for adhesion testing, which is a flat copper substrate plated with 0.5 μm of chromium. Die shear strength with copper plate is 7.0N / mm 2 By controlling the die shear strength to the following value, the mold releasability of the cured product of the encapsulating resin composition from the mold can be improved, and continuous moldability can be improved. The die shear strength is preferably 6.5 N / mm 2 More preferably, it is 6.0 N / mm2 More preferably, it is 5.0 N / mm 2 More preferably, it is 4.5 N / mm 2 The following is the result. On the other hand, the lower limit of the die shear strength is not particularly limited, and the lower the better. However, from the viewpoint of maintaining good handleability of the encapsulating resin composition, it is preferable that the lower limit of the die shear strength is 0.01 N / mm 2 More preferably, it is equal to or greater than this.

[0018] The encapsulating resin composition that satisfies condition i can be realized by combining known methods, and examples of such methods include controlling the combination of various materials that constitute the encapsulating resin composition, the blending amounts of various materials, controlling the manufacturing conditions of the encapsulating resin composition, etc. For example, examples of such methods include adjusting the combination of (A) epoxy resin, (B) phenolic curing agent, and (D) butadiene-acrylonitrile copolymer in the encapsulating resin composition, controlling the content of (D) butadiene-acrylonitrile copolymer, and the content of structural units derived from butadiene and acrylonitrile in the copolymer.

[0019] Furthermore, when the encapsulating resin composition of this embodiment is injection molded under conditions of a mold temperature of 175°C, an injection pressure of 9.8 MPa, and a curing time of 120 seconds, and then post-cured by heat treatment at 175°C for 4 hours to prepare a test specimen, it is preferable that the flexural strength and flexural modulus (in accordance with JIS K 6911) of the test specimen at 260°C satisfy the following, respectively. The bending strength is preferably 5 to 100 MPa, more preferably 10 to 80 MPa, and further preferably 15 to 50 MPa. The flexural modulus is preferably 100 to 1000 MPa, more preferably 200 to 900 MPa, and further preferably 300 to 800 MPa.

[0020] Hereinafter, each component contained in the encapsulating resin composition of the present embodiment will be described.

[0021] [(A) Epoxy resin] (A) Epoxy resin is a compound having two or more epoxy groups in one molecule, and may be any of a monomer, oligomer, and polymer.

[0022] Specifically, the (A) epoxy resin is one or more selected from the group consisting of crystalline epoxy resins such as biphenyl-type epoxy resins, bisphenol-type epoxy resins, and stilbene-type epoxy resins; novolac-type epoxy resins such as phenol novolac-type epoxy resins and cresol novolac-type epoxy resins; polyfunctional epoxy resins such as trisphenylmethane-type epoxy resins and alkyl-modified triphenolmethane-type epoxy resins; phenol aralkyl-type epoxy resins such as phenylene skeleton-containing phenol aralkyl-type epoxy resins and biphenylene skeleton-containing phenol aralkyl-type epoxy resins; naphthol-type epoxy resins such as dihydroxynaphthalene-type epoxy resins and epoxy resins obtained by glycidyl etherifying a dimer of dihydroxynaphthalene; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; and bridged cyclic hydrocarbon compound-modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins. Two or more types are more preferred.

[0023] From the viewpoint of obtaining good mold releasability and continuous moldability, the (A) epoxy resin is preferably one or more selected from the group consisting of trisphenylmethane type epoxy resins, biphenyl aralkyl type polyfunctional epoxy resins, orthocresol type difunctional epoxy resins, biphenyl type difunctional epoxy resins, and bisphenol type difunctional epoxy resins. From a similar viewpoint, the (A) epoxy resin is preferably one or more selected from the group consisting of tris(hydroxyphenyl)methane type epoxy resins, biphenylene skeleton-containing phenol aralkyl type epoxy resins, ortho-cresol novolac type epoxy resins, 3,3,5,5'-tetramethylbiphenyl glycidyl ether type epoxy resins, and dicyclopentadiene skeleton-containing polyfunctional solid epoxy resins, more preferably one or more selected from the group consisting of biphenylene skeleton-containing phenol aralkyl type epoxy resins, 3,3',5,5'-tetramethylbiphenyl glycidyl ether type epoxy resins, and dicyclopentadiene skeleton-containing polyfunctional solid epoxy resins, and even more preferably a biphenylene skeleton-containing phenol aralkyl type epoxy resin.

[0024] From the viewpoint of obtaining suitable fluidity during molding and improving filling properties and continuous moldability, the content of the (A) epoxy resin is preferably 2 mass % or more, more preferably 3 mass % or more, and further preferably 4 mass % or more, based on the entire encapsulating resin composition. In addition, from the viewpoint of improving the reliability of a semiconductor device obtained by using the encapsulating resin composition, the content of the (A) epoxy resin is preferably 40 mass % or less, more preferably 30 mass % or less, even more preferably 20 mass % or less, and even more preferably 10 mass % or less, based on the entire encapsulating resin composition.

[0025] [(B) Phenol-based hardener] As the (B) phenol-based curing agent, any monomer, oligomer or polymer having two or more phenolic hydroxyl groups in one molecule can be used, and there are no limitations on the molecular weight or molecular structure.

[0026] Examples of the (B) phenol-based curing agent include novolac-type phenolic resins such as phenol novolac resin, cresol novolac resin, and bisphenol novolac; polyvinylphenol; multifunctional phenolic resins such as phenol-hydroxybenzaldehyde resin and triphenolmethane-type phenolic resin; modified phenolic resins such as terpene-modified phenolic resin and dicyclopentadiene-modified phenolic resin; aralkyl-type phenolic resins such as phenol aralkyl resin having at least one of a phenylene skeleton and a biphenylene skeleton, and naphthol aralkyl resin having at least one of a phenylene skeleton and a biphenylene skeleton; and bisphenol compounds such as bisphenol A and bisphenol F. These may be used alone or in combination of two or more. Among these, from the viewpoint of obtaining good continuous moldability while improving the insulating properties of a semiconductor device obtained by using the encapsulating resin composition, it is more preferable to use one or more selected from the group consisting of trisphenolmethane type phenolic resins, biphenylaralkyl type phenolic resins, novolac type phenolic resins, biphenylene skeleton-containing phenolaralkyl type resins and biphenylene skeleton-containing phenolaralkyl type-formaldehyde polycondensates.

[0027] In the present embodiment, the content of the (B) phenol-based curing agent is, from the viewpoint of realizing excellent fluidity during molding and improving filling property and continuous moldability, preferably 0.5 mass % or more, more preferably 1 mass % or more, even more preferably 2 mass % or more, and particularly preferably 3 mass % or more, based on the entire encapsulating resin composition. In addition, from the viewpoint of improving the moisture resistance reliability and reflow resistance of a semiconductor device obtained using the encapsulating resin composition, the content of the (B) phenolic curing agent is preferably 25 mass % or less, more preferably 15 mass % or less, and even more preferably 10 mass % or less, based on the total mass of the encapsulating resin composition.

[0028] The equivalent ratio (EP / OH) of all epoxy groups (EP) to all phenolic hydroxyl groups (OH) used in the encapsulating resin composition of this embodiment is preferably 0.5 or more and 2 or less, and more preferably 0.8 or more and 1.7 or less, from the viewpoint of suppressing deterioration of moisture resistance, curing property, etc.

[0029] [(C) Inorganic filler] As the inorganic filler (C), any filler that is generally used in semiconductor encapsulation resin compositions can be used, and the inorganic filler (C) may be one that has been subjected to a surface treatment.

[0030] Specific examples of the (C) inorganic filler include silica such as fused silica, crystalline silica, and amorphous silicon dioxide; alumina; talc; titanium oxide; silicon nitride; and aluminum nitride. These inorganic fillers may be used alone or in combination of two or more.

[0031] (C) The inorganic filler preferably contains silica from the viewpoint of excellent versatility. Examples of the shape of silica include fused spherical silica, fused crushed silica, crystalline silica, etc. For example, from the viewpoint of suppressing an increase in the melt viscosity of the encapsulating resin composition, spherical silica is preferred.

[0032] From the viewpoint of improving continuous moldability and adhesion, the average diameter (D50) of the (C) inorganic filler is preferably 0.1 μm or more, more preferably 0.3 μm or more, and is preferably 80 μm or less, more preferably 50 μm or less, and even more preferably 40 μm or less. (C) The particle size distribution of the inorganic filler can be obtained by measuring the particle size distribution of the particles on a volume basis using a commercially available laser diffraction particle size distribution measuring device (for example, SALD-7000 manufactured by Shimadzu Corporation).

[0033] From the viewpoint of improving continuous moldability and adhesion, the (C) inorganic filler preferably has a plurality of peaks in particle size distribution measured by laser diffraction particle size distribution measurement, and more preferably has at least one peak between 0.1 and 5 μm and at least one peak between 10 and 30 μm.

[0034] In order to increase the content of the inorganic filler (C), the particle size distribution of the inorganic filler (C) may be adjusted to be broader.

[0035] The content of the (C) inorganic filler is preferably 50 mass % or more, more preferably 60 mass % or more, and even more preferably 65 mass % or more, based on the entire encapsulating resin composition, from the viewpoints of improving the low moisture absorption and low thermal expansion properties of the encapsulating material formed using the encapsulating resin composition while obtaining the releasability of the cured product, and more effectively improving the moisture resistance reliability and reflow resistance of the resulting semiconductor device. In addition, from the viewpoint of more effectively improving the fluidity and filling property during molding of the encapsulating resin composition, the content of the (C) inorganic filler is preferably 97 mass % or less, more preferably 95 mass % or less, and even more preferably 90 mass % or less, based on the entire encapsulating resin composition.

[0036] [(D) Butadiene-acrylonitrile copolymer] (D) Butadiene-acrylonitrile copolymer imparts releasability to the cured product and also acts to bind (A) epoxy resin and (C) inorganic filler to the semiconductor element and organic substrate, which are components of the semiconductor device. In addition, it is presumed that because (D) butadiene-acrylonitrile copolymer is compatible with the mixture of (A) epoxy resin and (B) phenol-based hardener and can be uniformly dispersed, releasability is maintained over the entire outer surface of the cured product, improving continuous moldability.

[0037] As the (D) butadiene-acrylonitrile copolymer, one having a structure represented by the following formula (1) is preferable.

[0038] [ka]

[0039] In the above formula (1), x and y are both positive numbers less than 1, and satisfy x+y=1. In particular, y is preferably 0.05 or more and 0.24 or less, and more preferably 0.07 or more and 0.20 or less.

[0040] By setting the content y of the structural unit derived from acrylonitrile within the above numerical range, it becomes possible to obtain an appropriate compatibility with the epoxy resin (A), and to easily obtain good continuous moldability.

[0041] The number average molecular weight of the butadiene-acrylonitrile copolymer (D) is preferably 2,000 or more and 5,000 or less, and more preferably 3,000 or more and 4,000 or less. The number average molecular weight can be calculated in terms of polystyrene using a GPC device such as HLC-8120 manufactured by Tosoh Corporation. By setting the number average molecular weight within the above range, it is possible to prevent the occurrence of poor filling during molding due to a decrease in fluidity.

[0042] The (D) butadiene-acrylonitrile copolymer is preferably liquid at 25° C. and has a viscosity of 50 to 160 Pa s. It is more preferably liquid at 40° C. and has a viscosity of 5 to 50 Pa s. This provides suitable fluidity and improves mold releasability and continuous moldability.

[0043] The content of the (D) butadiene-acrylonitrile copolymer is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, and even more preferably 0.1 mass % or more, based on the total mass of the encapsulating resin composition, from the viewpoints of obtaining releasability of the cured product while also obtaining flowability and adhesion. In addition, the content of the butadiene-acrylonitrile copolymer (D) is preferably 2 mass % or less, more preferably 1 mass % or less, and even more preferably 0.5 mass % or less, based on the entire encapsulating resin composition, in order to suppress an increase in viscosity and obtain good continuous moldability.

[0044] The encapsulating resin composition of the present embodiment may further contain the following components.

[0045] [(E) Curing accelerator] (E) The curing accelerator is used to accelerate the curing reaction between the epoxy groups in (A) the epoxy resin and the phenolic hydroxyl groups in (B) the phenol-based curing agent.

[0046] The (E) curing accelerator can include one or more types selected from the group consisting of phosphorus atom-containing compounds such as organic phosphines, tetra-substituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, and adducts of phosphonium compounds and silane compounds; nitrogen atom-containing compounds such as amidines and tertiary amines, exemplified by 1,8-diazabicyclo[5.4.0]undecene-7, benzyldimethylamine, and 2-methylimidazole, and quaternary salts of the above amidines and amines; and polyhydroxynaphthalene compounds, such as 2,3-dihydroxynaphthalene. Among these, from the viewpoint of improving the curability, it is more preferable to include a phosphorus atom-containing compound. Examples of phosphorus atom-containing compounds include 4-hydroxy-2-(triphenylphosphonium)phenolate. In addition, from the viewpoint of improving the balance between continuous moldability and curability, it is more preferable to include a compound having latency such as a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, or an adduct of a phosphonium compound and a silane compound.

[0047] From the viewpoint of improving the curing properties of the encapsulating resin composition, the content of the (E) curing accelerator is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, and even more preferably 0.1 mass % or more, based on the entire encapsulating resin composition. From the viewpoint of obtaining favorable fluidity during molding of the encapsulating resin composition while obtaining releasability of the cured product, the content of the (E) curing accelerator is preferably 2.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less, based on the total amount of the encapsulating resin composition.

[0048] [(F) Silicone oil] The silicone oil (F) is partially compatible with the resin component in a molten state, and partially incompatible with the resin component, and therefore exhibits a surface-active effect. As a result, even if a crystalline epoxy resin is used as the epoxy resin (A), for example, the recrystallization of the epoxy resin can be suppressed, and the variation in the curing property of the encapsulating resin composition can be reduced. In addition, when a mold release agent is used, the mold release agent is prevented from separating during molding and precipitating on the surface of the cured product, and mold contamination can be prevented.

[0049] Examples of the (F) silicone oil include epoxy-modified organopolysiloxanes, amino-modified organopolysiloxanes, hydrocarbon group-modified organopolysiloxanes, and polycaprolactone-modified organopolysiloxanes.

[0050] From the viewpoint of improving the curing properties of the encapsulating resin composition, the content of the (F) silicone oil is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, and even more preferably 0.1 mass % or more, based on the entire encapsulating resin composition. From the viewpoint of obtaining favorable fluidity during molding of the encapsulating resin composition while obtaining releasability of the cured product, the content of the (F) silicone oil is preferably 2.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less, based on the total mass of the encapsulating resin composition.

[0051] [Other ingredients] The encapsulating resin composition of the present embodiment may contain components other than the above-mentioned components. For example, one or more of various additives such as a coupling agent, a fluidity imparting agent, a release agent, an ion scavenger, a low stress component, a flame retardant, a colorant, and an antioxidant may be appropriately blended.

[0052] As the coupling agent, for example, various silane-based compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane; titanium-based compounds; aluminum chelates; aluminum / zirconium-based compounds and other known coupling agents can be used.

[0053] The aminosilane is not particularly limited, but examples thereof include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-phenylγ-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-6-(aminohexyl)3-aminopropyltrimethoxysilane, and N-(3-(trimethoxysilylpropyl)-1,3-benzenedimethanamine).

[0054] The content of the coupling agent is preferably from 0.01 to 10 parts by mass, and more preferably from 0.05 to 5 parts by mass, based on 100 parts by mass of the inorganic filler (C).

[0055] The release agent can include one or more selected from the group consisting of natural waxes such as carnauba wax; synthetic waxes such as Montan acid ester wax and oxidized polyethylene wax; higher fatty acids such as zinc stearate and metal salts thereof; paraffin; and carboxylic acid amides such as erucic acid amide. From the viewpoint of improving the releasability of the cured product of the encapsulating resin composition, the content of the release agent is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, even more preferably 0.1 mass % or more, and is preferably 2.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less, based on the entire encapsulating resin composition.

[0056] A specific example of the ion scavenger is hydrotalcite. From the viewpoint of improving the reliability of the encapsulating material, the content of the ion scavenger is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, and is preferably 1.0 mass % or less, more preferably 0.5 mass % or less, based on the entire encapsulating resin composition.

[0057] Specific examples of the low stress component include silicones and rubbers such as silicone rubber, silicone elastomer, and silicone resin. From the viewpoint of improving the reliability of the encapsulating material, the content of the low stress component is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, even more preferably 0.1 mass % or more, and is preferably 5 mass % or less, more preferably 3 mass % or less, and even more preferably 1 mass % or less, based on the entire encapsulating resin composition.

[0058] Specific examples of flame retardants include aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphazene. From the viewpoint of improving the flame retardancy of the encapsulating material, the content of the flame retardant is preferably 1 mass % or more, more preferably 5 mass % or more, and is preferably 20 mass % or less, more preferably 10 mass % or less, based on the entire encapsulating resin composition.

[0059] Specific examples of colorants include carbon black and red iron oxide. From the viewpoint of obtaining a preferable color tone of the encapsulating material, the content of the colorant is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and is preferably 2 mass % or less, more preferably 1 mass % or less, based on the entire encapsulating resin composition.

[0060] Specific examples of the antioxidant include hindered phenol compounds, hindered amine compounds, and thioether compounds.

[0061] <Sealing resin composition> The encapsulating resin composition of the present embodiment is solid at room temperature (25° C.), and its shape can be selected depending on the molding method of the encapsulating resin composition, etc., and examples thereof include a tablet form; a particulate form such as a powder form or a granule form; and a sheet form.

[0062] The encapsulating resin composition can be produced, for example, by mixing the above-mentioned components by known means, melt-kneading them with a kneader such as a roll, a kneader or an extruder, cooling, and then pulverizing them. After pulverization, the mixture may be molded to obtain a particulate or sheet-like encapsulating resin composition. For example, the particulate encapsulating resin composition may be molded into a tablet shape. For example, a sheet-like encapsulating resin composition may be obtained by a vacuum extruder. The degree of dispersion, flowability, etc. of the obtained encapsulating resin composition may be appropriately adjusted.

[0063] The encapsulating resin composition obtained in this embodiment has excellent adhesion to a metal member. More specifically, according to this embodiment, it is possible to improve the adhesion between the cured product of the encapsulating resin composition and a member made of Ag, Ni, Cu, or an alloy containing at least one of these elements. The encapsulating resin composition of the present embodiment can be used for transfer molding, injection molding, or compression molding. Moreover, by using the encapsulating resin composition obtained in this embodiment, a semiconductor device with excellent reliability can be obtained.

[0064] The melt viscosity of the encapsulating resin composition of this embodiment at 175° C. is 30 Pa s or less, and preferably 20 Pa s or less, which provides excellent moldability and excellent processing stability when a semiconductor element is encapsulated with the encapsulating resin composition.

[0065] <Semiconductor device> The semiconductor device in this embodiment is a semiconductor element encapsulated with the cured product of the encapsulating resin composition in this embodiment. Specific examples of the semiconductor element include integrated circuits, large-scale integrated circuits, transistors, thyristors, diodes, solid-state imaging elements, etc. The semiconductor element is preferably an element that does not involve light input or output, excluding optical semiconductor elements such as light receiving elements and light emitting elements (light emitting diodes, etc.).

[0066] The substrate of the semiconductor device is, for example, a wiring board such as an interposer, or a lead frame, and the semiconductor element is electrically connected to the substrate by wire bonding, flip chip connection, or the like.

[0067] Examples of semiconductor devices obtained by encapsulating a semiconductor element by encapsulation molding using an encapsulating resin composition include Mold Array Package (MAP), Quad Flat Package (QFP), Small Outline Package (SOP), Chip Size Package (CSP), Quad Flat Non-leaded Package (QFN), Small Outline Non-leaded Package (SON), Ball Grid Array (BGA), Lead Flame BGA (LF-BGA), Flip Chip BGA (FCBGA), Molded Array Process BGA (MAPBGA), Embedded Wafer-Level BGA (eWLB), Fan-In type eWLB, and Fan-Out type eWLB. The present invention will be described in more detail below with reference to the drawings.

[0068] 1 and 2 are cross-sectional views showing the configuration of a semiconductor device. Note that, in this embodiment, the configuration of the semiconductor device is not limited to that shown in FIGS. First, the semiconductor device 100 shown in FIG. 1 includes a semiconductor element 20 mounted on a substrate 30, and a sealing material 50 that seals the semiconductor element 20. The encapsulant 50 is composed of a cured product obtained by curing the encapsulating resin composition of the present embodiment described above.

[0069] 1 also illustrates a case where the substrate 30 is a circuit substrate. In this case, as shown in FIG. 1, a plurality of solder balls 60 are formed on the other surface of the substrate 30 opposite to the surface on which the semiconductor element 20 is mounted. The semiconductor element 20 is mounted on the substrate 30 and electrically connected to the substrate 30 via a wire 40. On the other hand, the semiconductor element 20 may be flip-chip mounted on the substrate 30. Here, the wire 40 is not limited to, but may be, for example, an Ag wire, a Ni wire, a Cu wire, an Au wire, or an Al wire, and it is preferable that the wire 40 is made of Au, Cu, or Ag, or an alloy containing one or more of these.

[0070] The sealing material 50 seals the semiconductor element 20 so as to cover, for example, one surface of the semiconductor element 20 opposite to the surface facing the substrate 30. In the example shown in FIG. 1, the sealing material 50 is formed so as to cover the other surface and the side surface of the semiconductor element 20. In the present embodiment, the encapsulant 50 is formed of a cured product of the above-mentioned encapsulating resin composition. Therefore, in the semiconductor device 100, the encapsulant 50 and the wires 40 have excellent adhesion, and therefore the semiconductor device 100 has excellent reliability. The encapsulant 50 can be formed, for example, by encapsulating and molding an encapsulating resin composition using a known method such as transfer molding or compression molding.

[0071] Fig. 2 is a cross-sectional view showing the configuration of a semiconductor device 100 in this embodiment, and shows an example different from that in Fig. 1. The semiconductor device 100 shown in Fig. 2 uses a lead frame as the substrate 30. In this case, the semiconductor element 20 is mounted on, for example, a die pad 32 of the substrate 30, and is electrically connected to an outer lead 34 via a wire 40. The encapsulant 50 is made of a cured product of the encapsulating resin composition in this embodiment, similar to the example shown in Fig. 1.

[0072] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted. EXAMPLES

[0073] (1) Raw materials (A) Epoxy resin Epoxy resin 1: Orthocresol novolac epoxy resin "CNE-195LL" manufactured by Chang Chun Plastics Co., Ltd. Epoxy resin 2: Phenol aralkyl type epoxy resin "NC-3000" manufactured by Nippon Kayaku Co., Ltd. Epoxy resin 3: Biphenyl type epoxy resin "YX4000K" manufactured by Mitsubishi Chemical Corporation

[0074] (B) Phenol-based hardener Phenol-based hardener 1: Phenol aralkyl type phenolic resin containing biphenylene skeleton "MEH-7851SS" manufactured by UBE

[0075] (C) Inorganic filler Inorganic filler 1: Spherical silica "FB-940" manufactured by Denka, particle size 15 μm Inorganic filler 2: Spherical silica "SO-C5" Admatechs, particle size 1.5μm Inorganic filler 3: Spherical silica "SO-C2" Admatechs, particle size 0.5μm

[0076] (D) Butadiene-acrylonitrile copolymer -Butadiene-acrylonitrile copolymer 1: A compound represented by the following formula (d1). Viscosity 39 Pa·s (40℃) [ka]

[0077] -Butadiene-acrylonitrile copolymer 2: A compound represented by the following formula (d2). Viscosity 10 Pa·s (40°C) [ka]

[0078] -Butadiene-acrylonitrile copolymer 3: A compound represented by the following formula (d3). Viscosity 39 Pa·s (40℃) [ka]

[0079] (E) Curing accelerator Curing accelerator 1: 4-hydroxy-2-(triphenylphosphonium)phenolate Curing accelerator 2: 2,3-dihydroxynaphthalene

[0080] (F) Silicone oil Silicone oil 1: Dimethylsiloxane-alkylcarboxylate-4,4'-(1-methylethylidene)bisphenol glycidyl ether copolymer (Sumitomo Bakelite Co., Ltd., M69B)

[0081] (others) Coupling agent 1: N-phenyl-3-aminopropyltrimethoxysilane Coupling agent 2: 3-mercaptopropyltrimethoxysilane Release agent 1: Carnauba wax "TOWAX-132" manufactured by Toa Kasei Co., Ltd. Ion scavenger 1: "DHT-4H" manufactured by Kyowa Chemical Industry Co., Ltd. Colorant 1: Carbon black, manufactured by Tokai Carbon Co., Ltd.

[0082] (2) Preparation of encapsulating resin composition Using the above raw materials, the components shown in Table 1 were mixed in a mixer. The resulting mixture was then kneaded with a roll, cooled, and pulverized to obtain an encapsulating resin composition in the form of a powder or granule.

[0083] (3) Evaluation and measurement of encapsulating resin composition <Condition i> Using a transfer molding machine ("KTS-15" manufactured by Kotaki Seiki Co., Ltd.), the encapsulating resin composition was injected into a mold in which a copper plate with a chrome-plated surface (chrome-plated copper substrate for adhesion evaluation manufactured by Aska Corporation, chrome plating treatment of 0.5 μm) was placed, at a mold temperature of 175° C., and cured by heating at 175° C. for 300 seconds. The die shear strength (speed 300 μm / sec, temperature 25° C.) (N / mm) between the obtained cured product of the encapsulating resin composition and the copper plate was measured. 2 ) was measured using a DAGE4000 model manufactured by Nordson Advanced Technology.

[0084] <Continuous molding> Continuous moldability: Using a low-pressure transfer automatic molding machine (Daiichi Seiko, GP-ELF), silicon chips and the like were encapsulated with the encapsulating resin composition under conditions of a mold temperature of 175°C, an injection pressure of 9.6 MPa, and a curing time of 90 seconds, and an 80-pin QFP (Cu lead frame, package outer dimensions: 14 mm × 20 mm × 2 mm thick, pad size: 6.5 mm × 6.5 mm, chip size: 6.0 mm × 6.0 mm × 0.35 mm thick) was continuously molded up to 150 shots. The evaluation criteria were as follows: ⊚: 150 shots of continuous molding were possible without any problems such as unfilling; ◯: 100 shots of continuous molding were possible without any problems such as unfilling; and ×: unfilling occurred within 50 shots.

[0085] <Flexural modulus, flexural strength> Using a low-pressure transfer molding machine (KTS-30, manufactured by Kotaki Seiki Co., Ltd.), the encapsulating resin composition was injected and molded under conditions of a mold temperature of 175°C, an injection pressure of 9.8 MPa, and a curing time of 120 seconds to obtain a molded product with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm. The molded product was then further heat-treated at 175°C for 4 hours to post-cure it, and used as a test specimen. The test pieces were used to measure the flexural modulus and flexural strength in accordance with JIS K 6911 at an atmospheric temperature of 260°C.

[0086] [Table 1] [Explanation of symbols]

[0087] 20 Semiconductor elements 30 Substrate 32 Die pad 34 Outer lead 40 Wire 50 Encapsulating material 60 Solder balls 100 Semiconductor device

Claims

1. (A) an epoxy resin; (B) a phenol-based curing agent; (C) an inorganic filler; (D) butadiene-acrylonitrile copolymer; and is configured to satisfy the following condition i. Condition i: Using a transfer molding machine, the encapsulating resin composition is injected into a mold in which a copper plate having a chrome-plated surface is placed at a mold temperature of 175° C., and cured by heating at 175° C. for 300 seconds. The die shear strength (speed 300 μm / sec, temperature 25° C.) between the obtained cured product of the encapsulating resin composition and the chrome-plated surface of the copper plate is 7.0 N / mm ２ The following is the result.

2. The encapsulating resin composition according to claim 1, (D) An encapsulating resin composition having a butadiene-acrylonitrile copolymer content of 0.01 to 2 mass % based on the total amount of the encapsulating resin composition.

3. The encapsulating resin composition according to claim 1 or 2, (D) An encapsulating resin composition, wherein the butadiene-acrylonitrile copolymer is represented by the following formula (1): 【Chemistry 1】 (In formula (1), x and y are both positive numbers less than 1 and satisfy x+y=1.)

4. The encapsulating resin composition according to claim 3, An encapsulating resin composition, wherein in formula (1), y is 0.05 or more and 0.24 or less.

5. The encapsulating resin composition according to claim 1 or 2, (A) An encapsulating resin composition comprising one or more epoxy resins selected from the group consisting of crystalline epoxy resins, novolac-type epoxy resins, polyfunctional epoxy resins, phenol aralkyl-type epoxy resins, naphthol-type epoxy resins, triazine nucleus-containing epoxy resins, and bridged cyclic hydrocarbon compound-modified phenol-type epoxy resins.

6. The encapsulating resin composition according to claim 1 or 2, (B) An encapsulating resin composition, wherein the phenol-based curing agent comprises one or more selected from the group consisting of a novolac-type phenolic resin, a multifunctional phenolic resin, a modified phenolic resin, an aralkyl-type phenolic resin, and a bisphenol compound.

7. The encapsulating resin composition according to claim 1 or 2, (E) The encapsulating resin composition further comprising a curing accelerator.

8. The encapsulating resin composition according to claim 1 or 2, (F) An encapsulating resin composition further comprising a silicone oil.

9. The encapsulating resin composition according to claim 1 or 2, An encapsulating resin composition used for encapsulating a semiconductor element.

10. A semiconductor device, comprising a semiconductor element encapsulated with the encapsulating resin composition according to claim 1 or 2.

Images