Method for producing semiconductor encapsulating resin composition

Abstract

The present invention provides a method for producing a resin composition for semiconductor encapsulation, which can give tablets with no defects in appearance and can be molded at a low temperature of 150°C or less in a short time of 120 seconds or less. [Solution] A method for producing a resin composition for semiconductor encapsulation, comprising: mixing a first powder composition essentially comprising 20 to 80 mass% of the total amount of (A) and (B) (C) (B), 250 to 1,200 mass% of (C) inorganic filler, 2 to 30 mass% of (D) curing accelerator, and 0.5 to 5 mass% of (E) black pigment, relative to 100 mass% of the total amount of (A) epoxy resin and (B) phenolic resin curing agent, such that the ratio of the number of epoxy groups in component (A) to the number of phenolic hydroxyl groups in component (B) is in the range of 0.5 to 1.5; and mixing a second powder composition essentially comprising 20 to 80 mass% of the total amount of (B) (D) and 10 to 20 mass% of the total amount of (E) (D).

Description

[Technical Field]

[0001] The present invention relates to a method for producing a resin composition for semiconductor encapsulation. [Background technology]

[0002] Conventional technologies use transfer molding to encapsulate devices such as ICs, LSIs, and discrete components, protecting them from physical and environmental stress. Transfer molding has traditionally been used as a low-cost, highly reliable, and highly productive process. Specifically, a tablet-shaped thermosetting resin composition is placed in a mold pot, heated and melted, and then pressurized with a plunger into the mold cavity at 150°C to 190°C. The mold is then typically cured for 45 to 180 seconds before being molded. In recent years, efforts to reduce CO2 emissions and achieve carbon neutrality have been promoted as one of the goals of the Sustainable Development Goals (SDGs). CO2 emissions are calculated by multiplying the CO2 emission coefficient by the amount of power consumed. The use of green energy with a low CO2 emission coefficient and reduced power consumption are required. In transfer molding, reducing the amount of power consumed by heaters to heat the mold and increasing production volume per unit time are effective. In other words, it is desirable to keep the mold temperature as low as possible and the curing time as short as possible.

[0003] To achieve short-term curing at low temperatures, a large amount of highly active curing accelerators must be added. However, semiconductor encapsulation resin compositions are first prepared by weighing and mixing predetermined amounts of components, such as a thermosetting resin (e.g., epoxy resin), a curing agent (e.g., phenolic resin), an inorganic filler, a curing accelerator, and a black pigment. The resulting mixture is then heated, melted, and kneaded in a kneading machine. After cooling, the mixture is crushed and molded into tablets. Because the temperature of the resin composition reaches 80 to 120°C during the heat-melting and kneading process in the kneading machine, adding a large amount of highly active curing accelerators can promote crosslinking between the epoxy resin and the curing agent. This can lead to increased viscosity and decreased fluidity, resulting in molding defects such as underfilling, wire deformation, and pad shifting.

[0004] In response to these issues, a resin composition for semiconductor encapsulation has been proposed in which an epoxy resin and an inorganic filler are mixed, heated to melt, kneaded, and crushed, and a phenolic resin, a curing accelerator, and an inorganic filler are mixed, heated to melt, kneaded, and crushed, and the two materials are packaged separately and mixed before molding (see, for example, Patent Document 1). This method requires the customer to have their own molding equipment, which may not be acceptable. Furthermore, the molding temperature is relatively high at 175°C, as the main focus is on transportation and storage at room temperature.

[0005] Another proposal involves obtaining a resin composition by mixing a first powder obtained by mixing, heating, melting, kneading, and crushing a first component containing an epoxy resin, the curing agent, and the inorganic filler but not a curing accelerator, and then dispersing and mixing the resulting powder with a second powder containing a curing accelerator (see, for example, Patent Documents 2 and 3). The second powder is a crushed product containing the curing accelerator as the main ingredient. When mixed with the first powder and formed into tablets, the curing accelerator is visible as white spots, resulting in poor appearance and customer unacceptability. Furthermore, the product is designed for transportation and storage at room temperature, and the molding temperature is 175°C, which may result in poor curing at low temperatures. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-5888 [Patent Document 2] Patent No. 5838659 [Patent Document 3] Patent No. 5824900 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the above problems, and aims to provide a method for producing a resin composition for semiconductor encapsulation, which can produce tablets without defective appearance and can be molded at a low temperature of 150°C or less in a short time of 120 seconds or less. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides: The following components (A) to (E): For a total of 100 parts by mass of (A) epoxy resin and (B) phenolic resin curing agent, (C) inorganic filler: 250 to 1,200 parts by mass, (D) curing accelerator: 2 to 30 parts by mass, and (E) Black pigment: 0.5 to 5 parts by mass wherein the ratio of the number of epoxy groups in component (A) to the number of phenolic hydroxyl groups in component (B) is in the range of 0.5 to 1.5, A first powder composition essentially comprising the following components (A), (B), (C), and (E): (A) epoxy resin, (B) 20 to 80% by mass of the total amount of phenolic resin curing agent; (C) inorganic fillers, and (E) 80 to 90% by mass of the total amount of black pigment and a second powder composition essentially comprising the following components (B), (D), and (E): (B) 20 to 80% by mass of the total amount of phenolic resin curing agent; (D) a curing accelerator, and (E) 10 to 20% by mass of the total amount of black pigment The present invention provides a method for producing a semiconductor encapsulating resin composition, comprising the step of mixing:

[0009] By using this method for producing a resin composition for semiconductor encapsulation, and by mixing two powder compositions in an appropriate compounding ratio, it is possible to obtain a resin molded product that has no defects in appearance even when tableted and has good curability and fluidity even at low temperatures.

[0010] In this case, it is preferable to use an epoxy resin represented by the following formula (1) as the component (A). [ka] (In the formula, X is a divalent group selected from the following formulae, and n is an integer of 1 to 10.) [ka]

[0011] Epoxy resins having no alkyl substituents at the ortho-position, such as those represented by the general formula (1), are preferred because they have excellent reactivity.

[0012] Furthermore, it is preferable to use an imidazole compound represented by the following formula (2) as the component (D). [ka] (wherein R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R 1 is a hydrogen atom or a methyl group.)

[0013] The imidazole compound represented by the above general formula (2) is preferred because the temperatures of the reaction initiation region and the active region are low.

[0014] Furthermore, it is possible to provide a method for producing a resin tablet for semiconductor encapsulation, which comprises, following the mixing step described above, a pressure molding step of pressing the obtained resin composition into a tablet shape.

[0015] By using such a method for producing a resin tablet for semiconductor encapsulation, it is possible to obtain a tablet free from white spots derived from the curing accelerator and free from defects in appearance.

[0016] Furthermore, a method for manufacturing a semiconductor device can be provided, which includes, following the pressure molding step described above, a step of transfer molding the obtained resin tablet for semiconductor encapsulation at a molding temperature of 150°C or less for a molding time of 120 seconds or less.

[0017] By using such a method for manufacturing a semiconductor device, it becomes possible to reduce power consumption, which contributes to reducing CO2 emissions. [Effects of the Invention]

[0018] As described above, according to the present invention, a semiconductor encapsulating resin composition can be produced with a high yield because the tablet surface is free of white spots derived from the curing accelerator and has no defects in appearance. Furthermore, a method for producing a semiconductor encapsulating resin composition can be provided that does not cause an increase in viscosity or a decrease in fluidity during the heating, melting, and kneading processes in a kneading machine, and does not cause molding defects such as underfilling, wire deformation, or pad shift when transfer molding a semiconductor device. Furthermore, the semiconductor encapsulating resin composition can be molded in a short time similar to conventional methods even at low molding temperatures, and can reduce CO2 emissions during the molding process, making it industrially useful. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present inventors have conducted extensive research to solve the above problems and have found that by separating the epoxy resin and phenolic curing agent into two powder compositions so that a curing accelerator is not present in the mixture during the heat-melting and kneading process in a kneader, and by adjusting the composition ratio of these powders appropriately, an increase in viscosity and a decrease in fluidity do not occur, and no unfilled spaces or wire deformation occur during transfer molding of semiconductor devices. Furthermore, they have found that the semiconductor encapsulating resin composition of the present invention can be molded in a short time similar to conventional methods, even at low molding temperatures, and have completed the present invention.

[0020] That is, the present invention provides a composition comprising the following components (A) to (E): For a total of 100 parts by mass of (A) epoxy resin and (B) phenolic resin curing agent, (C) inorganic filler: 250 to 1,200 parts by mass, (D) curing accelerator: 2 to 30 parts by mass, and (E) Black pigment: 0.5 to 5 parts by mass wherein the ratio of the number of epoxy groups in component (A) to the number of phenolic hydroxyl groups in component (B) is in the range of 0.5 to 1.5, A first powder composition essentially comprising the following components (A), (B), (C), and (E): (A) epoxy resin, (B) 20 to 80% by mass of the total amount of phenolic resin curing agent; (C) inorganic fillers, and (E) 80 to 90% by mass of the total amount of black pigment and a second powder composition essentially comprising the following components (B), (D), and (E): (B) 20 to 80% by mass of the total amount of phenolic resin curing agent; (D) a curing accelerator, and (E) 10 to 20% by mass of the total amount of black pigment The present invention relates to a method for producing a resin composition for semiconductor encapsulation, the method comprising the step of mixing the above components.

[0021] The present invention will be described in detail below, but the present invention is not limited thereto.

[0022] [(A) Epoxy resin] The semiconductor encapsulating resin composition of the present invention contains (A) an epoxy resin.

[0023] The epoxy resin (A) is not particularly limited, but examples thereof include epoxy resins conventionally used in the technical field of epoxy resin compositions for semiconductor encapsulation. Examples of such epoxy resins include crystalline epoxy resins such as phenol novolac epoxy resins, orthocresol novolac epoxy resins, naphthol novolac epoxy resins, biphenyl epoxy resins, bisphenol epoxy resins, stilbene epoxy resins, and dihydroanthracene diol epoxy resins; polyfunctional epoxy resins such as triphenol methane epoxy resins and alkyl-modified triphenol methane epoxy resins; phenol aralkyl epoxy resins having a phenylene skeleton; biphenyl aralkyl epoxy resins having a biphenylene skeleton; naphthol aralkyl epoxy resins having a phenylene skeleton; and polyfunctional epoxy resins such as triphenol methane epoxy resins and alkyl-modified triphenol methane epoxy resins. naphthol-type epoxy resins such as dihydroxynaphthalene-type epoxy resins and epoxy resins obtained by glycidyl etherifying dihydroxynaphthalene dimers; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; cyclic hydrocarbon compound-modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins; and copolymer compounds obtained by the hydrosilylation reaction of an alkenyl group-containing epoxy compound with a hydrogenorganopolysiloxane represented by the following average formula (3):

[0024] [ka] (wherein R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, a is 0.01≦a≦1, b is 1≦b≦3, and 1.01≦a+b<4)

[0025] The above resin or compound may be used alone or in combination of two or more kinds.

[0026] Examples of the alkenyl group-containing epoxy compound include those obtained by epoxidizing an alkenyl group-containing phenol resin with epichlorohydrin or by partially reacting a conventionally known epoxy compound with 2-allylphenol. The epoxy compound can be represented, for example, by the following average formula (4). [Chemical formula] (In the formula, R 2’ is an aliphatic monovalent hydrocarbon group having an alkenyl group, with 3 to 15 carbon atoms, preferably 3 to 5 carbon atoms, and R 3’ is a group represented by a glycidyloxy group or -OCH2CH(OH)CH2OR’, and R’ is a monovalent hydrocarbon group having an alkenyl group, with 3 to 10 carbon atoms, preferably 3 to 5 carbon atoms, k is 1, k ’ is 0 or 1, x is a positive number from 1 to 30, and y is a positive number from 1 to 3)

[0027] Examples of the epoxy compound represented by the above average formula include the following compounds. [Chemical formula] [Chemical formula] (In the formula, x and y are positive numbers represented by 1 < x < 10 and 1 < y < 3)

[0028] The hydrogen organopolysiloxane represented by the average formula (3) above has at least one SiH group per molecule. In formula (3), R represents an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, octyl, nonyl, or decyl; an alkenyl group such as vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, or octenyl; an aryl group such as phenyl, tolyl, xylyl, or naphthyl; an aralkyl group such as benzyl, phenylethyl, or phenylpropyl; or groups in which some or all of the hydrogen atoms have been substituted with halogen atoms such as fluorine, bromine, or chlorine, or a cyano group, such as a halogen-substituted alkyl group such as chloromethyl, chloropropyl, bromoethyl, or trifluoropropyl; or a cyanoethyl group. A methyl group, an ethyl group, or a phenyl group is preferred.

[0029] The organopolysiloxane represented by the above average formula (3) may be linear, cyclic, or branched, and can be represented, for example, by the following formulas (a) to (c). [ka] (In the formula, R is, independently of each other, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and R 9 is a hydrogen atom or a group selected from the options for R, and R 8 is the group shown below. 1 is an integer between 5 and 200, and n 2 is an integer between 0 and 2, and n 3 is an integer between 0 and 10, and n 4 is either 1 or 0.) [ka] (Wherein R and R 9 is as described above, and n 5 is an integer of 1 to 10. However, the compound of the above formula (a) has at least one hydrogen atom bonded to a silicon atom in one molecule.

[0030] [ka] (In the above formula (b), R is as defined above, and n 6 is an integer between 1 and 10, and n 7 is 1 or 2.)

[0031] [ka] (In the above formula (c), R and R 9 is as defined above, r is an integer of 0 to 3, and R 10 is a monovalent hydrocarbon group having 1 to 10 carbon atoms which may contain a hydrogen atom or an oxygen atom, and the compound of the above formula (c) has at least one hydrogen atom bonded to a silicon atom in one molecule.

[0032] Suitable examples of the hydrogen organopolysiloxane include hydrogen-terminated methylpolysiloxanes and hydrogen-terminated methylphenylpolysiloxanes. For example, the following compounds are preferred: [ka] (wherein n is an integer of 20 to 100) [ka] (wherein m is an integer of 1 to 10, and n is an integer of 10 to 100) Examples of the hydrogen organopolysiloxane include those mentioned above, and these may be used alone or in combination of two or more.

[0033] As component (A), an epoxy resin represented by the following general formula (1), which has no alkyl substituents at the ortho position, is desirable because it has excellent reactivity. [ka] (In the formula, X is a divalent group selected from the following formulae, and n is an integer of 1 to 10.) [ka]

[0034] [(B) Phenolic resin curing agent] The semiconductor encapsulating resin composition of the present invention contains (B) a phenolic resin curing agent.

[0035] Examples of (B) phenolic resin curing agents include novolac-type phenolic resins, naphthalene ring-containing phenolic resins, aralkyl-type biphenyl resins, aralkyl-type phenolic resins, triphenolalkane-type phenolic resins, biphenyl-type phenolic resins, alicyclic phenolic resins, heterocyclic phenolic resins, naphthalene ring-containing phenolic resins, bisphenol A-type phenolic resins, and bisphenol F-type phenolic resins, and these may be used alone or in combination of two or more. Among these, preferred are novolac-type phenolic resins, triphenolalkane-type phenolic resins, aralkyl-type biphenyl resins, aralkyl-type phenolic resins, and biphenylaralkyl-type phenolic resins, and particularly preferred are novolac-type phenolic resins, triphenolalkane-type phenolic resins, and aralkyl-type biphenyl resins.

[0036] The blending ratio of epoxy resin to curing agent (epoxy group / phenolic hydroxyl group) is an equivalent ratio of 0.5 to 1.5, preferably 0.8 to 1.2. Within this blending ratio range, the curing agent is appropriate, which is economically advantageous and prevents insufficient curing.

[0037] [(C) Inorganic filler] The semiconductor encapsulating resin composition of the present invention contains (C) an inorganic filler.

[0038] Examples of the (C) inorganic filler that can be used include fused silica, crystalline silica, cristobalite, alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fiber, alumina fiber, zinc oxide, talc, and calcium carbide. Two or more of these may be used in combination. The top cut diameter of the (C) inorganic filler, as determined by a wet sieve method, is preferably 5 to 150 μm, more preferably 10 to 75 μm, and the average particle size D50, as determined by a volume particle size distribution measured with a laser diffraction particle size analyzer, is preferably 5 to 50 μm, more preferably 8 to 40 μm. The top cut diameter here refers to the mesh size of the sieve used to classify the produced inorganic filler by the wet sieve method, and refers to the value at which the proportion of particles larger than the mesh size is 2% by volume or less in the volume particle size distribution measured by the laser diffraction method.

[0039] The amount of inorganic filler (C) added is 250 to 1,200 parts by mass, preferably 250 to 1,000 parts by mass, and more preferably 400 to 850 parts by mass, per 100 parts by mass of the total of components (A) and (B).

[0040] [(D) Curing accelerator] The semiconductor encapsulating resin composition of the present invention contains (D) a curing accelerator.

[0041] (D) Examples of curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, trimellitate, 1-cyanoethyl-2-phenylimidozolium trimellitate, 2,4-diamino-6-[2'-methylimidozolium] 2,4-Diamino-6-[2'-undecylimidazolyl-(1')]ethyl-s-triazine, 2,4-Diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenyl Imidazoles such as imidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, and 1H-imidazole; 1,8-diazabicyclo[5.4.Examples of suitable organic amines include tertiary amines such as 0]undecene-7, triethylenediamine, and benzyldimethylamine; organic phosphines such as triphenylphosphine, tributylphosphine, and tetraphenylphosphonium tetraphenylborate, as well as microencapsulated versions of these; and compounds having a urea structure such as N,N,N',N'-tetramethylurea, N'-phenyl-N,N-dimethylurea, N,N-diethylurea, N'-[3-[[[(dimethylamino)carbonyl]amino]methyl]-3,5,5-trimethylcyclohexyl]-N,N-dimethylurea, and N,N"-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea). These may be used alone or in combination of two or more.

[0042] Among the curing accelerators, imidazole compounds represented by the following general formula (2) are preferred because the temperatures of the reaction initiation region and the active region are low. [ka] (wherein R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R 1 is a hydrogen atom or a methyl group.)

[0043] The amount of curing accelerator added is 2 to 30 parts by mass, preferably 3 to 15 parts by mass, per 100 parts by mass of the total of (A) epoxy resin and (B) phenolic resin curing agent components. Within this range, the epoxy groups and phenolic hydroxyl groups react quickly even at low temperatures, allowing a cured product to be obtained in a short time.

[0044] [(E) Black pigment] The semiconductor encapsulating resin composition of the present invention contains (E) a black pigment.

[0045] (E) Examples of black pigments include carbon black, titanium black, FeCr2O4, and CuCr2O4, and these may be used alone or in combination of two or more.

[0046] The amount of black pigment added is 0.5 to 5 parts by mass, and more preferably 1 to 3 parts by mass, per 100 parts by mass of the total of (A) epoxy resin and (B) phenolic resin curing agent components. Within this range, the cured product will have a grayish black to black color and will not impair its electrical properties.

[0047] [Other additives] The resin composition of the present invention may further contain additives such as a mold release agent, a flame retardant, an ion trapping agent, a flexibility imparting agent, an adhesion aid, and the like, as required.

[0048] Examples of the release agent include waxes such as carnauba wax, rice wax, polyethylene, polyethylene oxide, montanic acid, ester compounds of montanic acid with saturated alcohols, 2-(2-hydroxyethylamino)-ethanol, ethylene glycol, glycerin, etc.; stearic acid, stearic acid esters, stearic acid amide, ethylene bisstearic acid amide, copolymers of ethylene and vinyl acetate, etc., and these may be used alone or in combination of two or more.

[0049] Examples of the flame retardant include halogenated epoxy resins, phosphazene compounds, silicone compounds, zinc molybdate-supported talc, zinc molybdate-supported zinc oxide, aluminum hydroxide, magnesium hydroxide, molybdenum oxide, antimony trioxide, etc. These flame retardants may be used alone or in combination of two or more, but from the viewpoint of environmental load and ensuring fluidity, phosphazene compounds, zinc molybdate-supported zinc oxide, molybdenum oxide, aluminum hydroxide, and magnesium hydroxide are preferably used.

[0050] Examples of the ion trapping agent include hydrotalcite compounds, bismuth compounds, and zirconium compounds, and these may be used alone or in combination of two or more.

[0051] Examples of the flexibility-imparting agent include silicone compounds such as silicone oil, silicone resin, silicone-modified epoxy resin, and silicone-modified phenolic resin, and thermoplastic elastomers such as styrene resin and acrylic resin, and these may be used alone or in combination of two or more.

[0052] Adhesion aids include N-[3-trimethoxysilyl)propyl]-[1,3,5]triazine-2,4,6-triamine, N-[3-triethoxysilyl)propyl]-[1,3,5]triazine-2,4,6-triamine, (1-{2-[4,6-diamino-(1,3,5)triazin-2-yl]-ethyl}-3-[3-(trimethoxysilyl)propyl]urea, 1-{2-[4,6-diamino-(1,3,5)triazin-2-yl]-ethyl}-3-[3-(triethoxysilyl)propyl]urea, 3-isocyanatepropyltriethoxysilane, 3-ureidopropyltriethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, tris-(triethylsilylpropyl)isocyanurate, 1-(3 -(trimethoxysilyl)propyl)-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3-(trimethoxysilyl)propyl)1,3,5-triazine-2,4,6(1H,3H,5H)-trione, N-[5-(trimethoxysilyl)-2-aza-1-oxopentyl]caprolactam, N-[5-(triethoxysilyl)-2-aza-1-oxopentyl]caprolactam, N-[3-(triethoxysilyl)propyl]-carbamic acid ethyl ester, N-[3-(trimethoxysilyl)propyl]-carbamic acid ethyl ester, 3,5-dimethyl-N-[3-(trimethoxysilyl)propyl]-1H-pyrazole-1-carboxamide, 3,5-Dimethyl-N-[3-(triethoxysilyl)propyl]-1H-pyrazole-1-carboxamide, 2-[3-(trimethoxysilyl)propyl]succinic anhydride, 2-[3-(triethoxysilyl)propyl]succinic anhydride, N-(trimethoxysilylpropyl)-1H-benzotriazole-1-carbodiamide, Dihydro-3-(trimethoxysilylpropyl)-2,5-furandione, 2,2-Dimethoxy-1-phenyl-1-aza-2-silacyclopentane, N-2-pyridinyl-N-(triethoxysilylpropyl)-urea, 3-[(trimethoxysilyl)propyl]-1H-imidazole, 3-Methacryloxypropyltrimethoxysilane, 3-Methacryloxypropyltriethoxysilane, 3-Methacryloxypropylmethyl Examples of suitable silanes include epoxy silanes such as dimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, p-styryltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino silanes such as N-2(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane; and mercaptosilanes such as 3-mercaptosilane. These may be used alone or in combination of two or more.

[0053] The content of these other additives in the resin composition may be determined appropriately within a range that allows each additive to exhibit its function well, and is, for example, in the range of 0.1 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the total of (A) the epoxy resin and (B) the phenolic resin curing agent component.

[0054] [Method of producing resin composition] The semiconductor encapsulating resin composition of the present invention is produced, for example, as follows. First, (A) epoxy resin, 20 to 80 mass% of the total blend amount of (B) phenolic resin curing agent, (C) inorganic filler, (E) 80 to 90 mass% of the total blend amount of black pigment, and other materials are blended in predetermined amounts and thoroughly mixed uniformly using a mixer or the like. After that, the mixture is melt-mixed and kneaded at a temperature of 80 to 120°C using a kneading machine such as a heat roll, kneader, or extruder, and then cooled and solidified, and pulverized to an appropriate size to obtain a first powder composition. Separately, a predetermined amount of the curing accelerator (D), 20 to 80 mass% of the total amount of the phenolic resin curing agent (B), and 10 to 20 mass% of the total amount of the black pigment (E) are blended and mixed thoroughly and uniformly using a mixer or the like, and then melt-mixed and kneaded at a temperature of 80 to 120°C using a kneading machine such as a heat roll, kneader, or extruder.The mixture is then cooled and solidified, pulverized to an appropriate size, and sieved through a 150 μm mesh to obtain a second powder composition. The first powder composition and the second powder composition are prepared separately, but either one may be produced first, or they may be produced separately and simultaneously.

[0055] In the second powder composition, if the phenolic resin curing agent (B) is less than 20% by mass of the total blend amount, it is difficult to melt-mix the curing accelerator (D) with the phenolic resin curing agent (D). If it is more than 80% by mass of the total blend amount, the amount of phenolic resin curing agent in the first powder becomes too small, making kneading difficult. Furthermore, if the phenolic resin curing agent is in a large amount, the reactivity becomes faster. In the second powder composition, if the amount of the black pigment (E) is less than 10% by mass of the total amount blended, white spots may appear on the tablet surface, and if it is more than 20% by mass of the total amount blended, black spots may appear.

[0056] As a crushing device, a general crushing machine such as a power mill, a sample mill, or a roll crusher can be used.

[0057] The particle size of the first powder composition is preferably 30% or less of particles 75 μm or less and 5% or less of particles 1,400 μm or more. If the proportion of particles 75 μm or less exceeds 30%, aggregation may occur in the hopper during the tablet production process. If the proportion of particles 1,400 μm or more exceeds 5%, the bulk density may decrease, making it impossible to produce large sizes during the tablet production process.

[0058] The particle size of the second powder composition is preferably fine so that it can be dispersed evenly throughout the gaps in the first powder composition. Specifically, the proportion of particles between 45 μm and 150 μm is preferably 70% or more. Furthermore, the proportion of coarse particles of 150 μm or more is preferably 1% or less. The particle size is a value measured by the following method.

[0059] [Measurement method] A sieve with a specified mesh size was set in a sieve shaker, and 100 g of the powder composition was sieved at an amplitude of 1.5 mm / g for 10 minutes, and the mass on each sieve was measured to determine the weight.

[0060] Next, the first powder composition and the second powder composition are blended in predetermined amounts and thoroughly and uniformly mixed using a mixer or the like to obtain the desired semiconductor encapsulation resin composition. A pressure molding step may be performed, in which the mixture is further pressed into a tablet shape with a good appearance. Examples of methods for molding into tablets include placing the mixture in a mold with a tablet size (diameter, height, weight) tailored to the customer's requirements and compression molding using a compression molding machine at a compression ratio of 80 to 95%. While the size of the tablet is not particularly limited, specific examples include a shape in which the outer diameter D is 20 mm or less and the ratio L / D of the outer diameter D to the length L is 1 or greater; or a shape in which the outer diameter D is 20 mm or greater and the ratio L / D of the outer diameter D to the length L is 1 or less.

[0061] [Uses and methods of use of semiconductor encapsulation resin composition] Semiconductor devices that can be encapsulated with the semiconductor encapsulation resin composition produced by the method of the present invention include, but are not limited to, transistor types, module types, dual in-line packages (DIPs), quad flat packages (QFPs), low-profile quad flat packages (LQFPs), small outline packages (SOPs), small outline J-lead packages (SOJs), thin small outline packages (TSOPs), thin quad flat packages (TQFPs), tape carrier packages (TCPs), ball grid arrays (BGAs), and chip-size packages (CSPs). The method for encapsulating semiconductor devices with the semiconductor encapsulation resin composition can be used for transfer molding, injection molding, compression molding, etc., but is particularly suitable for transfer molding, which is used for mass production.

[0062] That is, the present invention can provide a method for manufacturing a semiconductor device, which includes, following the pressure molding step described above, a step of transfer molding the obtained resin tablet for semiconductor encapsulation at a molding temperature of 150°C or less for a molding time of 120 seconds or less.

[0063] The mold temperature during molding is typically 175°C, but when the semiconductor encapsulation resin composition is used, molding can be performed at 130 to 150°C. The curing time is also typically 45 to 120 seconds, but molding can be performed within the same curing time. A semiconductor device in which an element is encapsulated by the above-described molding method is generally mounted on an electronic device after a process known as post-cure, in which the resin composition is completely cured at a temperature of about 150 to 200°C for about 1 to 6 hours. A semiconductor device encapsulated with the semiconductor encapsulation resin composition can be completely cured by post-cure at a temperature of about 130 to 180°C for about 10 minutes to 1 hour.

[0064] From the above, by using the semiconductor encapsulation resin composition, it is possible to reduce power consumption in the molding process and post-cure process, which can contribute to reducing CO2 emissions.

[0065] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0066] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0067] The raw materials used in the examples and comparative examples are shown below.

[0068] (A) Epoxy resin Epoxy resin 1: NC-2000L (Nippon Kayaku Co., Ltd., phenol aralkyl type) [ka] Epoxy resin 2: NC-3000 (Nippon Kayaku Co., Ltd., biphenyl aralkyl type) [ka] Epoxy resin 3: EPPN-501H (manufactured by Nippon Kayaku Co., Ltd., triphenolmethane type) [ka] Epoxy resin 4: A copolymer of an alkenyl group-containing epoxy compound and a hydrogenorganopolysiloxane synthesized according to the synthesis example below.

[0069] Synthesis Example A 1-liter four-neck flask equipped with a reflux condenser, thermometer, stirrer, and dropping funnel was charged with 200 g of allyl glycidyl ether-modified phenolic novolac resin (phenol equivalent 125, allyl equivalent 1100), 800 g of chloromethyloxirane, and 0.6 g of cetyltrimethylammonium bromide. The mixture was heated and stirred at 110°C for 3 hours. The mixture was cooled to 70°C and the pressure was reduced to 160 mmHg. Then, 128 g of a 50% aqueous solution of sodium hydroxide was added dropwise over 3 hours with azeotropic dehydration. The resulting mixture was evaporated under reduced pressure to remove the solvent. The resulting mixture was then dissolved in a mixed solvent of 300 g of methyl isobutyl ketone and 300 g of acetone, washed with water, and the solvent was evaporated under reduced pressure to obtain an allyl-containing epoxy resin (allyl equivalent 1590, epoxy equivalent 190). This epoxy resin was mixed with 170g of methyl isobutyl ketone, 330g of toluene, and 0.07g of a 2% platinum 2-ethylhexanol-modified chloroplatinic acid solution. The mixture was subjected to azeotropic dehydration for 1 hour, and then 133g of an organohydrogenpolysiloxane represented by formula (5) was added dropwise over 30 minutes at reflux temperature. After stirring for 4 hours at the same temperature, the resulting mixture was washed with water and the solvent was distilled off under reduced pressure, yielding a whitish-yellow, opaque solid copolymer. The epoxy equivalent was 280, the ICI melt viscosity at 150°C was 800cP, the silicon content was 31%, and the epoxy equivalent was 323. [ka]

[0070] (B) Phenolic resin hardener TD-2131 (DIC Corporation, phenol novolac type)

[0071] (C) Inorganic filler Spherical fused silica (Tatsumori Co., Ltd., average particle size = 15 μm)

[0072] (D) a curing accelerator; Curing accelerator 1: 1H-imidazole (SIZ Shikoku Chemicals Co., Ltd.) Curing accelerator 2: 2-methylimidazole (2MZ-H manufactured by Shikoku Chemicals Co., Ltd.) Curing accelerator 3: 2-undecylimidazole (C11Z manufactured by Shikoku Chemicals Co., Ltd.)

[0073] (E) Black pigment Black pigment 1: Mitsubishi Carbon #3230MJ (carbon black, manufactured by Mitsubishi Chemical Corporation) Black pigment 2: Tilac D (TSV Ako Kasei Co., Ltd., low-order titanium dioxide) Black pigment 3: LD-38S (Shepherd Colors, Inc., CuCr2O4)

[0074] (others) Ion trapping agent: DHT-4A-2 (manufactured by Toagosei Co., Ltd.) Release agent: TOWAX-131 (manufactured by Toa Kasei Co., Ltd.) Adhesion aid: KBM-403 (Shin-Etsu Chemical Co., Ltd.)

[0075] (Production of Resin Composition) Examples 1 to 7, Comparative Examples 1 to 4 The first powder components listed in Table 1 were mixed at room temperature using a blade rotary mixer, melt-kneaded in a twin-screw kneader set at 100 ° C, cooled, and then pulverized in a power mill to obtain a first powder. The second powder components listed in Table 1 were then mixed at room temperature using a blade rotary mixer, melt-kneaded in a twin-screw kneader set at 80 ° C, cooled, and then pulverized in a sample mill. The second powder was obtained by sieving through a 150 μm mesh sieve. Next, a predetermined amount of the first powder and the second powder were weighed, rotated at room temperature for 3 minutes in a blade rotary mixer, and dispersed and mixed to obtain a resin composition. The resulting resin composition was then molded into tablets using a tablet machine under a pressure of 2 MPa to obtain resin tablets with a compression ratio of 90%, a diameter of 16 mm, and a weight of 8.0 g.

[0076] Comparative Example 5 The first powder components listed in Table 1 were mixed at room temperature in a rotary blade mixer, melt-kneaded in a twin-screw kneader set at 100°C, cooled, and then pulverized in a power mill to obtain the first powder. The second powder component, 2MZ-H, was pulverized in a mortar and passed through a sieve with 45 μm openings.

[0077] The first powder and the second powder were weighed in predetermined amounts and mixed in a rotary blade mixer at room temperature for 3 minutes to obtain a resin composition. The resin composition was then molded into tablets using a tablet machine under a pressure of 2 MPa to obtain resin tablets with a compression ratio of 90%, a diameter of 16 mm, and a weight of 8.0 g.

[0078] Comparative Example 6 The components listed in Table 2 were mixed at room temperature in a rotary blade mixer, melt-kneaded in a twin-screw kneader set at 100°C, cooled, and then pulverized in a power mill to obtain a resin composition. The resulting resin composition was then molded into tablets using a tablet machine under a pressure of 2 MPa to obtain resin tablets with a compression ratio of 90%, a diameter of 16 mm, and a mass of 8.0 g.

[0079] The obtained resin tablets were evaluated by the following methods, and the results are shown in Tables 1 and 2.

[0080] Evaluation method <Tablet appearance> The appearance was visually observed, and a sample with less than three white or black spots was judged to be acceptable, while a sample with three or more spots was judged to be unacceptable.

[0081] <Fluidity; Spiral Flow> Using a mold conforming to the EMMI standard, measurements were taken under conditions of a mold temperature of 130°C, injection pressure of 6.9 MPa, and curing time of 120 seconds.

[0082] <Melt viscosity> Using a high-performance flow tester (Shimadzu Corporation, CFT-500), the temperature was 130°C and the pressure was 10 kgf / cm. 2 The measurement was performed with a capillary diameter of 1.0 mm.

[0083] <Room temperature storage stability; Spiral flow> The resin composition was stored in a sealed plastic bag at 25°C for 72 hours. Then, using a mold according to the EMMI standard, measurements were taken under the conditions of a mold temperature of 130°C, an injection pressure of 6.9 MPa, and a curing time of 120 seconds. The rate of change from the initial value was determined.

[0084] <Gelation time> Using a curastometer (registered trademark) MODEL7 (manufactured by JSR Trading Co., Ltd.), the torque change at 130°C was measured, and the time when the torque reached 0.04 N·m was defined as the gelation time. obtained.

[0085] <TO-247 package formability> The TO-247 package was injection molded 10 shots at a mold temperature of 130°C, an injection pressure of 6.9 MPa, and curing times of 120 seconds and 180 seconds, and the presence or absence of mold sticking in the product part, the presence or absence of flash, the presence or absence of runner sticking, and the presence or absence of unfilled package were observed.

[0086] <Glass transition temperature> Using a transfer molding machine, cured products of 5 mm × 5 mm × 15 mm were obtained at a mold temperature of 130°C, an injection pressure of 6.9 MPa, and a curing time of 120 seconds. Further post-cured at 180°C for 30 minutes, and these cured products were set in a thermomechanical analyzer (TMA8140C, manufactured by Rigaku Corporation). The heating rate program was set to a heating rate of 5°C / min, and after setting so that a constant load of 49 mN was applied to the test piece of the cured product, the dimensional change of the test piece was measured between 25°C and 300°C. The relationship between this dimensional change and temperature was plotted on a graph. From the graph of the dimensional change and temperature thus obtained, the glass transition temperature was determined.

[0087]

Table 1

[0088]

Table 2

[0089] As shown in Table 1 above, the semiconductor encapsulation resin compositions (Examples 1 to 7) produced by the production method of the present invention had good tablet appearance and showed excellent fluidity and curability even at a low temperature of 130°C, equivalent to the evaluation results at a general curing temperature of 175°C. On the other hand, in the semiconductor encapsulation resin compositions obtained by the production method of the present invention, in Comparative Examples 1 to 5 in which the blending amounts of the first powder and second powder components were different, the tablet appearance was unacceptable in all Comparative Examples. In Comparative Example 6, in which the two powder components were not mixed separately, the tablet appearance was acceptable, but the fluidity and hardening properties were inferior to those of the Examples.

[0090] The semiconductor encapsulation resin composition produced by the production method of the present invention is industrially useful because it can reduce the amount of electricity consumed by a heater for heating a mold in a transfer molding process and contribute to reducing CO2 emissions.

[0091] The present specification includes the following aspects. [1] The following components (A) to (E): For a total of 100 parts by mass of (A) epoxy resin and (B) phenolic resin curing agent, (C) inorganic filler: 250 to 1,200 parts by mass, (D) curing accelerator: 2 to 30 parts by mass, and (E) Black pigment: 0.5 to 5 parts by mass wherein the ratio of the number of epoxy groups in component (A) to the number of phenolic hydroxyl groups in component (B) is in the range of 0.5 to 1.5, A first powder composition essentially comprising the following components (A), (B), (C), and (E): (A) epoxy resin, (B) 20 to 80% by mass of the total amount of phenolic resin curing agent; (C) inorganic fillers, and (E) 80 to 90% by mass of the total amount of black pigment and a second powder composition essentially comprising the following components (B), (D), and (E): (B) 20 to 80% by mass of the total amount of phenolic resin curing agent; (D) a curing accelerator, and (E) 10 to 20% by mass of the total amount of black pigment 1. A method for producing a semiconductor encapsulating resin composition, comprising: [2] The method for producing a semiconductor encapsulating resin composition according to [1], characterized in that the component (A) is an epoxy resin represented by the following formula (1): [ka] (In the formula, X is a divalent group selected from the following formulae, and n is an integer of 1 to 10.) [ka] [3] The method for producing a semiconductor encapsulating resin composition according to [1] or [2], wherein the component (D) is an imidazole compound represented by the following formula (2): [ka] (wherein R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R 1 is a hydrogen atom or a methyl group.) [4] A method for producing a resin tablet for semiconductor encapsulation, characterized by comprising, following the mixing step described in any one of [1] to [3], a pressure molding step of pressing the obtained resin composition into a tablet shape. [5] A method for manufacturing a semiconductor device, comprising the step of transferring the obtained resin tablet for semiconductor encapsulation at a molding temperature of 150°C or less for a molding time of 120 seconds or less after the pressure molding step described in [4].

[0092] The present invention is not limited to the above-described embodiments, which are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that provides similar effects is included within the technical scope of the present invention.

Claims

1. The following components (A) to (E): For a total of 100 parts by mass of (A) epoxy resin and (B) phenolic resin curing agent, (C) inorganic filler: 250 to 1,200 parts by mass, (D) curing accelerator: 2 to 30 parts by mass, and (E) Black pigment: 0.5 to 5 parts by mass wherein the ratio of the number of epoxy groups in component (A) to the number of phenolic hydroxyl groups in component (B) is in the range of 0.5 to 1.5; A first powder composition comprising the following components (A), (B), (C), and (E): (A) an epoxy resin, (B) 20 to 80% by mass of the total amount of the phenolic resin curing agent, (C) an inorganic filler, and (E) 80 to 90% by mass of the total amount of black pigment and a second powder composition essentially comprising the following components (B), (D), and (E): (B) 20 to 80% by mass of the total amount of the phenolic resin curing agent, (D) a curing accelerator, and (E) 10 to 20% by mass of the total amount of black pigment 1. A method for producing a semiconductor encapsulating resin composition, comprising:

2. 2. The method for producing a semiconductor encapsulating resin composition according to claim 1, wherein the component (A) is an epoxy resin represented by the following formula (1): 【Chemistry 1】 (In the formula, X is a divalent group selected from the following formulae, and n is an integer of 1 to 10.) 【Chemistry 2】

3. 2. The method for producing a semiconductor encapsulating resin composition according to claim 1, wherein the component (D) is an imidazole compound represented by the following formula (2): 【Transformation 3】 (wherein R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R １ is a hydrogen atom or a methyl group.)

4. 4. A method for producing a resin tablet for semiconductor encapsulation, comprising, after the mixing step according to claim 1, a pressure molding step of pressing the obtained resin composition into a tablet shape.

5. 5. A method for manufacturing a semiconductor device, comprising the step of transfer molding the obtained semiconductor encapsulation resin tablet at a molding temperature of 150° C. or less for a molding time of 120 seconds or less, following the pressure molding step according to claim 4.

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