JP2012067252A - Sealing epoxy resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmentally friendly sealing epoxy resin composition good in thermal conductivity, flame retardancy, strength, and moldability and excellent in mold release after being molded and in burr formation resistance and to provide a semiconductor device using such composition.SOLUTION: There are disclosed a sealing epoxy resin composition consisting essentially of (A) a cresol novolac epoxy resin, (B) a phenol novolac resin, (C) triphenylphosphine, (D) a mixture containing 70 mass% or more crystalline silica of an average particle diameter of 10-30 μm, 10 mass% or less crystalline silica of an average particle diameter of below 3.0 μm, 5-15 mass% spherical fused silica of an average particle diameter of below 3.0 μm, and 5-15 mass% spherical fused silica of an average particle diameter of 5-15 μm, (E) a phosphazene compound, and (F) a metal hydrate and/or a metal borate, wherein the content of component (D) to the entire composition amount is 70-85 mass%, and a semiconductor device prepared by sealing a semiconductor element with a cured product of such composition.

Description

  The present invention relates to an epoxy resin composition for sealing, and a semiconductor device using the same, and more specifically, has high thermal conductivity, flame retardancy, and environmental friendliness useful for power device applications. The present invention relates to an excellent epoxy resin composition for sealing and a semiconductor device using the same.

  Epoxy resin compositions used for resin sealing of semiconductor devices such as power devices are required to have high thermal conductivity in order to cope with a large amount of heat released from the element. Therefore, in order to obtain good thermal conductivity, for example, an epoxy resin composition in which crystalline silica and fused spherical silica having a small particle diameter are used in combination and filled with an inorganic filler at a high density has been proposed (for example, Patent Documents 1 and 2).

  However, increasing the filling amount of the inorganic filler decreases the fluidity of the composition. As a result, for example, when applied to a semiconductor device in which the island portion of the inner lead is bent and the semiconductor element is mounted, the balance of the fluidity of the resin composition on the front and back of the inner lead in the mold cavity is achieved. There is a possibility that a failure such as a void may occur, a bonding wire may be deformed, or an island shift may occur may occur.

  On the other hand, in recent years, in order to reduce the burden on the environment, there has been a demand for an epoxy resin composition for sealing that imparts good flame retardancy without using a halogen flame retardant. The use of metal hydrates such as aluminum hydroxide and magnesium hydroxide as a flame retardant instead of a flame retardant has been studied.

  However, in order to obtain high flame retardancy with a metal hydrate, it is necessary to add a large amount of the metal hydrate, and there is concern about a decrease in the mechanical strength of the molded product. In response to this problem, if a metal hydrate having a small particle size is used, the flame retardancy can be increased and the amount of use can be reduced. Decrease the property and curability. Then, in order to make high flame retardance, favorable fluidity | liquidity, and sclerosis | hardenability compatible, the composition using the metal hydrate which has a specific particle size distribution is proposed (for example, refer patent document 3).

  However, when applied to an epoxy resin composition for sealing that is highly filled with silica powder in order to obtain a good thermal conductivity as described above, only by specifying the particle size of the metal hydrate, good fluidity and In addition to being unable to obtain curability and the like, the target thermal conductivity may not be obtained.

  Furthermore, in order to improve the releasability from the mold, the epoxy resin composition for sealing is usually blended with waxes, but the metal hydrate has a large oil absorption amount, so it is easy to absorb the waxes. There was also a problem that mold releasability was lowered. If molding is performed in a state in which the releasability is lowered, the molded product may be cracked or chipped. Particularly, when the strength of the resin composition is low, the occurrence of these problems is remarkable. To deal with this problem, for example, it is conceivable to increase the amount of the release agent or to use a release agent having a high release property. The number of molds and the surface of the semiconductor device is likely to become dirty, which may impair productivity.

  In addition, as a flame retardant, a sealing epoxy resin composition containing a cross-linked phosphazene compound and a cyclic compound without using a metal hydrate, or a sealing epoxy resin using a cross-linked phenoxyphosphazene compound and zinc borate in combination. Resin compositions have been proposed (see, for example, Patent Documents 4 and 5). However, in the former, due to the large amount of the organic flame retardant, the thermal conductivity and strength are lowered, and there is a possibility that the semiconductor device may be cracked or chipped. In the latter case, when a plurality of cavities are connected in series by the through-gate method and molded using a mold with an increased number of elements per unit area, so-called slit burrs may be a problem. there were.

Japanese Patent No. 2811933 JP 2001-44337 A JP 2000-109647 A JP 2005-8835 A JP 2002-37979 A

  The present invention has been made to solve the above-mentioned problems of the prior art, and has a good balance of thermal conductivity, flame retardancy, strength and moldability, mold release from the mold during molding, An object of the present invention is to provide an epoxy resin composition for sealing excellent in suppression and less burden on the environment, and a highly reliable semiconductor device sealed using such an epoxy resin composition for sealing Yes.

  As a result of intensive research to achieve the above object, the present inventors have found that cresol novolac type epoxy resin, phenol novolac resin, triphenylphosphine, specific silica powder, phosphazene compound, metal hydrate and / or boron. The inventors have found that the above object can be achieved by a specific sealing epoxy resin composition containing an acid metal salt as an essential component and a semiconductor device using the same, and have completed the present invention.

  That is, the epoxy resin composition for sealing according to one embodiment of the present invention includes (A) a cresol novolac type epoxy resin, (B) a phenol novolac resin, (C) triphenylphosphine, (D) (d1) an average particle diameter. 70% by mass or more of crystalline silica powder of 10 to 30 μm, (d2) 10% by weight or less of crystalline silica powder having an average particle size of less than 3.0 μm, (d3) 5 to 15 mass of fused spherical silica powder having an average particle size of less than 3.0 μm And (d4) a silica powder mixture comprising 5 to 15% by mass of fused spherical silica powder having an average particle size of 0.5 to 3 μm, (E) a phosphazene compound, and (F) a metal hydrate and / or a metal borate A salt is an essential component, and the ratio of the (D) silane powder mixture to the entire composition is 70 to 85% by mass.

  A semiconductor device according to another aspect of the present invention is characterized in that a semiconductor element is sealed with a cured product of the above-described sealing epoxy resin composition having a thermal conductivity of 2 W / mK or more. .

  According to the present invention, the balance of thermal conductivity, flame retardancy, strength and moldability is good, the mold releasability from the mold at the time of molding, the suppression of burrs, and the environmental load is small An epoxy resin composition for use, and a semiconductor device with excellent reliability sealed using such an epoxy resin composition for sealing can be obtained.

  Embodiments of the present invention will be described below.

First, each component used for the epoxy resin composition for sealing of this invention is demonstrated.
The component (A) cresol novolac type epoxy resin used in the present invention is characterized by excellent moldability and solder heat resistance. From the viewpoint of curability, the epoxy equivalent is preferably in the range of 150 to 300, more preferably in the range of 180 to 250. Specifically, as the component (A), ESCN-190 manufactured by Sumitomo Chemical Co., Ltd. (trade name of o-cresol novolac type epoxy resin; epoxy equivalent 195, softening point 65 ° C.) is preferably used. . A cresol novolac type epoxy resin may be used individually by 1 type, and 2 or more types may be mixed and used for it. Although the compounding quantity of this cresol novolak type epoxy resin is not specifically limited, The range of 7-35 mass% is preferable with respect to the whole quantity of a composition, and the range of 8-15 mass% is more preferable. If it is less than 7% by mass, the water absorption rate may increase. Moreover, when it exceeds 35 mass%, there exists a possibility that a flame retardance may fall.

  In the present invention, an epoxy resin other than the cresol novolac type epoxy resin can be used in combination as necessary. For example, for the purpose of adjusting curability etc., phenol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, naphthalene type epoxy resin, triphenolmethane type epoxy resin, containing triazine nucleus Epoxy resins, biphenyl type or stilbene type bifunctional epoxy compounds can be used. These epoxy resins may be used individually by 1 type, and 2 or more types may be mixed and used for them. When using together with another epoxy resin, it is preferable to mix | blend in the range of 50 mass% or less of epoxy resin total mass. A more preferable range is 30% by mass or less of the total mass of the epoxy resin.

  As the phenol novolak resin of component (B) used in the present invention, if it has two or more phenolic hydroxyl groups in the molecule that can react with the epoxy group of the cresol novolak type epoxy resin of component (A), It is used without particular limitation. For the purposes of the present invention, those having a phenolic hydroxyl group equivalent in the range of 100 to 200 are preferred, and those having a phenolic hydroxyl group equivalent in the range of 100 to 150 are particularly preferred from the viewpoint of curability. Moreover, the thing of the range whose softening point is 50-110 degreeC is preferable, and the thing of the range which is 70-90 degreeC is more preferable. Specifically, H-1 (trade name; hydroxyl equivalent 106, softening point 83 ° C.) manufactured by Meiwa Kasei Co., Ltd. is preferably used as the component (B). A phenol novolac resin may be used individually by 1 type, and 2 or more types may be mixed and used for it. The amount of this phenol novolak resin is equivalent to the phenolic hydroxyl group equivalent in the phenol novolak resin per one equivalent of the epoxy group in the cresol novolac type epoxy resin of the above component (A) and other epoxy resins blended as necessary. Is preferably in the range of 0.5 to 2.0 equivalents, more preferably in the range of 0.8 to 1.20 equivalents. In the range of less than 0.5 equivalent, flame retardancy and the like may be reduced. Moreover, in the range exceeding 2.0 equivalent, there exists a possibility that a water absorption rate may increase and reliability may fall.

  In this invention, the phenol resin which acts as a hardening | curing agent of the said epoxy resin other than a phenol novolak resin can be used together as needed. Specifically, modified resins of novolak type phenol resins such as cresol novolak resin, phenol aralkyl resin, naphthol aralkyl resin, phenol novolak resin, cresol novolak resin (for example, epoxidized or butylated novolak type phenol resin), di A cyclopentadiene modified phenol resin, a paraxylene modified phenol resin, a triphenolalkane type phenol resin, a polyfunctional type phenol resin, or the like can be used. These may be used individually by 1 type, and may mix and use 2 or more types. When using other phenol resin together, it is preferable to mix | blend in the range of 50 mass% or less of phenol resin total mass. A more preferable range is 30% by mass or less of the total mass of the phenol resin. When a phenol resin other than phenol novolac resin is used in combination, the phenolic hydroxyl group equivalent in the resin is the cresol novolac type epoxy resin of component (A), and other epoxy resins blended as necessary. The range described above, that is, a range of 0.5 to 2.0 equivalents per equivalent of epoxy group is preferable, and a range of 0.8 to 1.20 equivalents is more preferable.

  In the sealing epoxy resin composition of the present invention, (C) triphenylphosphine is used as a curing accelerator for promoting the reaction between the epoxy resin and the phenol resin. Triphenylphosphine having a low impurity concentration is preferable. Although the compounding quantity of this triphenylphosphine is not specifically limited, The range of 0.01-5 mass% is preferable with respect to the whole quantity of a composition. By mixing triphenylphosphine within this range, good mold releasability can be obtained. As a result, the cycle of mold cleaning can be extended, so that the continuous formability is excellent. Moreover, if the compounding quantity of triphenylphosphine is less than 0.01 mass%, gel time will become long and the production cycle of a semiconductor device will become long. On the other hand, if it exceeds 5% by mass, the fluidity is lowered and the filling property becomes poor, and the moisture resistance reliability after mounting may be lowered. A more preferable range is a range of 0.05 to 1.0% by mass with respect to the total amount of the composition.

  In the present invention, if necessary, a known curing accelerator other than triphenylphosphine, for example, a phosphorus curing accelerator, an imidazole curing accelerator, a DBU (diazabicycloundecene) curing accelerator, It can use together in the range which does not inhibit the effect of this invention. These curing accelerators may be used alone or in combination of two or more.

  The silica powder mixture of component (D) used in the present invention comprises (d1) crystalline silica powder having an average particle size of 10 to 30 μm, preferably 25 to 30 μm, and (d2) an average particle size of less than 3.0 μm, preferably 0.00. 5 to 2.0 μm crystalline silica powder, (d3) fused spherical silica powder having an average particle size of less than 3.0 μm, preferably 0.5 to 1.5 μm, and (d4) average particle size of 5 to 15 μm, preferably 8 It is a mixture of fused spherical silica powder of ˜15 μm.

  The silica powder mixture of component (D) is the total amount of components (d1) to (d4), and is blended in a proportion of 70 to 85% by mass, preferably 75 to 85% by mass, based on the total amount of the composition. When the proportion of the silica powder mixture is less than 70% by mass, the thermal conductivity is low, and when it exceeds 85% by mass, the fluidity is lowered and molding becomes difficult.

  In the silica powder mixture of component (D), the ratio of (d1) crystalline silica powder having an average particle size of 10 to 30 μm is 70% by mass or more, preferably 70 to 75% by mass, and (d2) average particle size of 3 The proportion of crystalline silica powder of less than 0.0 μm is 10% by weight or less, preferably 5 to 10% by weight. (D1) The ratio of the crystalline silica powder having an average particle diameter of 10 to 30 μm is less than 70% by mass, or (d2) the ratio of the crystalline silica powder having an average particle diameter of less than 3.0 μm is more than 10% by weight. High thermal conductivity cannot be expressed.

  In the silica powder mixture of component (D), the ratio of (d3) fused spherical silica powder having an average particle size of less than 3.0 μm is 5 to 15% by mass, preferably 5 to 10% by mass, and (d4) average The ratio of the fused spherical silica powder having a particle size of 5 to 15 μm is 5 to 15% by mass, preferably 5 to 10% by mass. If any of (d3) fused spherical silica powder having an average particle size of less than 3.0 μm and (d4) fused spherical silica powder having an average particle size of 5 to 15 μm is out of the above ratio, the fluidity is lowered. Molding becomes difficult.

  Furthermore, in the present invention, the mass ratio (d3) / (d4) of (d3) fused spherical silica powder having an average particle size of less than 3.0 μm and (d4) fused spherical silica powder having an average particle size of 5 to 15 μm is 0. It is preferable that it is .75-1.25. By setting the mass ratio (d3) / (d4) within the above range, the balance of the resin composition between the inner lead and the island front and back in the mold cavity is improved, and the occurrence of voids, island shift, bonding wire deformation, etc. Can be suppressed. The mass ratio (d3) / (d4) is more preferably 0.85 to 1.15.

  The average particle size of the silica powder is a particle size at which the cumulative weight becomes 50% in the particle size distribution measured by a laser diffraction particle size distribution measuring device (product name: Cirrus Laser Type 920, manufactured by Horiba, Ltd.).

  The phosphazene compound of component (E) used in the present invention is a component that imparts flame retardancy to the sealing epoxy resin composition of the present invention, together with component (F) described below. As the phosphazene compound, a crosslinked phenoxyphosphazene compound obtained by crosslinking a phenoxyphosphazene compound with a crosslinking group such as a phenylene group is particularly preferably used.

（式中、ｍは３〜２５の整数を表す）

（式中、Ｘは基−Ｎ＝Ｐ（ＯＣ₆ Ｈ₅ ）₃ または基−Ｎ＝Ｐ（Ｏ）ＯＣ₆ Ｈ₅ を、Ｙは基−Ｐ（ＯＣ₆ Ｈ₅ ）₄ または基−Ｐ（ＯＣ₆ Ｈ₅ ）₂ を、ｎは３〜１００００の整数をそれぞれ表す） Examples of the phenoxyphosphazene compound include a cyclic phenoxyphosphazene compound represented by the following structural formula (1), a chain phenoxyphosphazene compound represented by the following structural formula (2), and the like.

(In the formula, m represents an integer of 3 to 25)

Wherein X is a group —N═P (OC ₆ H ₅ ) ₃ or a group —N═P (O) OC ₆ H ₅ , Y is a group —P (OC ₆ H ₅ ) ₄ or a group —P ( OC ₆ H ₅ ) ₂ and n represents an integer of 3 to 10,000)

（式中、Ａは基−Ｃ（ＣＨ₃ ）₂ −、基−ＳＯ₂ −、基−Ｓ−または基−Ｏ−を、ａは０または１を表す） Moreover, as a crosslinking group, the bisphenylene group etc. which are represented by following Structural formula (3) other than a phenylene group are mentioned.

(Wherein A represents a group —C (CH ₃ ) ₂ —, a group —SO ₂ —, a group —S— or a group —O—, and a represents 0 or 1).

  As the phosphazene compound of component (E), a crosslinked phenoxyphosphazene compound is preferable. A phosphazene compound may be used individually by 1 type, and may mix and use 2 or more types.

  The blending amount of the phosphazene compound is not particularly limited, but is preferably in the range of 0.1 to 3.0% by mass, and in the range of 0.1 to 2.0% by mass with respect to the total amount of the composition. More preferred. If it is less than 0.1% by mass, the effect of imparting flame retardancy is not sufficient, and if it exceeds 3.0% by mass, the reliability of the semiconductor device may be lowered.

  The component (F) used in the present invention is a metal hydrate and / or a boric acid metal salt that releases crystal water at a temperature of 180 ° C. or higher or releases water by thermal decomposition. . Examples of the metal hydrate include aluminum hydroxide and magnesium hydroxide. Specific examples of commercially available aluminum hydroxide include B-52, B-73, B-1403, and B-703 (all are trade names) manufactured by Nippon Light Metal Co., Ltd. H-100E, H-210, H-310, H-X, H-42M (all are trade names), etc. Specific examples of commercially available magnesium hydroxide include water manufactured by Kamiwa Chemical Co., Ltd., such as Kisuma 5A, Kisuma 5B, Kisuma 5E (all of which are trade names). Examples thereof include a mug 10 and a water mug 10A (all are trade names).

Examples of the boric acid metal salt include borax, zinc borate, aluminum borate, magnesium borate and the like. Among these, zinc borate having a crystal water discharge temperature of 200 ° C. or higher and having a low-molecular gas capturing ability is preferable. Zinc borate is generally a hydrate having a formula represented by 2ZnO · 3B ₂ O ₃ · xH ₂ O (x = 3.3 to 3.7), but x is 3.5 and 260 Those which are stable up to a temperature of 0 ° C. or higher are preferred. Specific examples of preferable commercial products of zinc borate include Alkanex FRF-30, Alkanex FRC-150, Alkanex FRC-500, Alkanex FRC-600 (above, manufactured by Mizusawa Chemical Co., Ltd.) All of them are trade names) and Firebreak ZB (trade names) manufactured by Rio Taint Japan Co., Ltd. Incidentally Arca Nex FRC-500 is a _{2ZnO · 3B 2 O 3 · 3.5H} 2 O.

  In addition, a metal hydrate and a boric acid metal salt may each be used individually by 1 type, and 2 or more types may be mixed and used for them.

  The metal hydrate and / or borate metal salt of component (F) as a whole preferably has an average particle size of 20 μm or less and a maximum particle size of 100 μm or less, and an average particle size of 10 μm or less and a maximum More preferably, the particle size is 50 μm or less. When the average particle diameter exceeds 20 μm, or the maximum particle diameter exceeds 100 μm, there is a possibility of causing a decrease in fluidity, a decrease in filling property, a wire flow, and the like. Furthermore, the metal hydrate and metal borate used for the component (F) preferably have a particle size of 0.1 to 50 μm, and more preferably 0.2 to 30 μm. When the particle size is less than 0.1 μm, the specific surface area increases, so that the amount of oil absorption increases, and the fluidity and mold releasability may decrease. On the other hand, if the particle diameter exceeds 50 μm, the mechanical strength may be lowered in some cases.

  The average particle size, maximum particle size, and particle size of the metal hydrate and metal borate are determined by, for example, a laser diffraction particle size distribution analyzer (product name: Cirrus Laser Type 920, manufactured by Horiba, Ltd.). The average particle size is a particle size at which the cumulative weight is 50% in the particle size distribution measured by the same apparatus.

  (F) Although the compounding quantity of the metal hydrate of a component and / or a boric-acid metal salt is not specifically limited, The range of 5-15 mass% is preferable with respect to the whole quantity of a composition, 7-10 A range of mass% is more preferred. If it is less than 5% by mass, the effect of imparting flame retardancy is not sufficient, and if it exceeds 15% by mass, the moldability and adhesive strength as a sealing material are reduced and the moisture absorption rate is increased, thereby improving the reliability of the semiconductor device. May be reduced.

  In the sealing epoxy resin composition of the present invention, a coupling agent can be further blended for the purpose of enhancing the filling property, the adhesion between the inorganic filler and the resin, and the like. Examples of the coupling agent include silane coupling agents, titanium coupling agents, aluminum chelates, aluminum / zirconium-based compounds, and the like, and silane coupling agents are particularly preferable from the viewpoint of the effect of addition.

  Examples of preferred silane coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, N-β-aminoethyl. -Γ-aminopropyltrimethoxysilane and the like. For example, γ-glycidoxypropyltrimethoxysilane is NUC A-187, γ-mercaptopropyltrimethoxysilane is NUC A-189, γ-aminopropyltriethoxysilane is NUC A-1100, γ-ureidopropyltriethoxysilane. NUC A-1160 and N-β-aminoethyl-γ-aminopropyltrimethoxysilane are trade names NUC A-1120, both of which are commercially available from Unicar Corporation.

  The blending amount of the coupling agent is preferably in the range of 0.03 to 5.0% by mass with respect to the total amount of the composition, from the viewpoint of the effect by addition, heat resistance, cost, etc. % Range is more preferred.

  In addition to the above components, the sealing epoxy resin composition of the present invention generally contains a synthetic wax, natural wax, ester, metal salt of linear fatty acid, acid amide, etc. A release agent, a colorant such as carbon black, a low-stress imparting agent such as silicone oil and silicone rubber, and the like can be blended as necessary within a range that does not impair the effects of the present invention.

  The general preparation method of the epoxy resin composition for sealing of the present invention is as follows. First, in a dry mixing apparatus, (D) component silica powder mixture, (E) component phosphazene compound, and (F) component metal hydrate. Add and / or add metal borate and mix. In addition, you may make it add (d1)-(d4) component of (D) component separately to a dry-type mixing apparatus, without mixing previously. Next, (A) cresol novolac type epoxy resin, (B) phenol novolac resin, (C) triphenylphosphine, and various components blended as necessary are added in a powder state and mixed uniformly. Thereafter, the mixture is melt-kneaded with a two-roll, continuous kneader, etc., formed into a sheet, cooled, and pulverized to an appropriate size. .

  The semiconductor device of this invention can be manufactured by sealing various semiconductor elements using the said epoxy resin composition for sealing. Examples of semiconductor elements that perform sealing include ICs, diodes, thyristors, and transistors. As a sealing method, a low-pressure transfer method is generally used, but sealing by injection molding, compression molding, casting, or the like is also possible. After sealing with the sealing epoxy resin composition, the semiconductor device is finally heated and cured to be sealed with the cured product. The cured product preferably has a thermal conductivity of 2 W / m · K or more measured by a hot wire method.

  The sealing epoxy resin composition of the present invention has high thermal conductivity, good fluidity, excellent moldability, good mold releasability, and excellent halogen-free flame retardancy. is doing. Therefore, it is very useful as a sealing material for various semiconductor devices, especially as a sealing material for semiconductor devices such as transistors, diodes, and thyristors called power devices.

  Next, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to these Examples at all. In the following description, “part” means “part by mass”.

Example 1
As silica powder, 57 parts of crystalline silica powder having an average particle diameter of 11 μm (trade name MCC-4; expressed as crystalline silica powder (d1) manufactured by Tatsumori Co., Ltd.), crystalline silica powder having an average particle diameter of 1.5 μm ) Tatsumori product name 5X; crystalline silica powder (indicated as d2)) 7 parts, fused spherical silica powder having an average particle size of 0.5 μm (trade name SO-25R, manufactured by Admatechs Co., Ltd.) fused spherical silica powder (d3) )) 5 parts, 5 parts of fused spherical silica powder having an average particle size of 5.8 μm (trade name FB-7SDC manufactured by Denki Kagaku Kogyo Co., Ltd .; designated as fused spherical silica powder (d4)), and metal borate As a salt, 10 parts of zinc borate having an average particle diameter of 8 μm (trade name: FRC-150, manufactured by Mizusawa Chemical Industry Co., Ltd.) is placed in a mixer and stirred with a silane coupling agent (trade name, manufactured by Nippon Unicar Co., Ltd.). -9669) 0. 5 parts were added for surface treatment. Thereafter, 0.2 part of silicone oil (trade name KF-101, manufactured by Shin-Etsu Silicone Co., Ltd.) was added.

  Furthermore, o-cresol novolak type epoxy resin (trade name ESCN-190, manufactured by Sumitomo Chemical Co., Ltd .; epoxy equivalent 195, softening point 65 ° C.) 9.7 parts, phenol novolac resin (trade name, manufactured by Meiwa Kasei Co., Ltd.) -1; hydroxyl group equivalent 106, softening point 83 ° C. 4.8 parts, triphenylphosphine (trade name PP-360, manufactured by Keiai Kasei Co., Ltd.) 0.15 parts, crosslinked phenoxyphosphazene (trade name, manufactured by Otsuka Chemical Co., Ltd.) 0.15 part of SPE-100), refined carnauba wax (trade name No-1 manufactured by Celerica NODA) 0.3 part, and carbon black (trade name MA-600 manufactured by Mitsubishi Chemical Corporation) 0.2 part After mixing at room temperature, the mixture was kneaded at 60 to 70 ° C. using a biaxial roll kneader, cooled and pulverized to produce a sealing epoxy resin composition.

(Example 2)
A sealing epoxy resin composition was produced in the same manner as in Example 1 except that the amount of zinc borate (trade name FRC-150) was changed to 7.0 parts.

(Example 3)
A sealing epoxy resin composition was produced in the same manner as in Example 1 except that the addition amount of zinc borate (trade name FRC-150) was changed to 15.0 parts.

Example 4
Sealed in the same manner as in Example 1 except that aluminum hydroxide (trade name B-1403 manufactured by Nippon Light Metal Co., Ltd.) having an average particle diameter of 1.0 μm was used instead of zinc borate (trade name FRC-150). An epoxy resin composition was prepared.

(Example 5)
For sealing in the same manner as in Example 1 except that magnesium hydroxide (trade name Echo Mug, manufactured by Tateho Chemical Industry Co., Ltd.) having an average particle diameter of 1.0 μm was used instead of zinc borate (trade name FRC-150). An epoxy resin composition was produced.

(Example 6)
Instead of 10.0 parts of zinc borate (trade name FRC-150), 5.0 parts of the same zinc borate (trade name FRC-150) and aluminum hydroxide having an average particle size of 1.0 μm (trade name B-1403) ) A sealing epoxy resin composition was produced in the same manner as in Example 1 except that 5.0 parts was used.

(Example 7)
The same procedure as in Example 1 except that the addition amount of triphenylphosphine (trade name PP-360) was 0.30 parts and the addition amount of zinc borate (trade name FRC-150) was 8.0 parts. An epoxy resin composition for sealing was produced.

(Example 8)
o-cresol novolac type epoxy resin (trade name ESCN-190), phenol novolac resin (trade name H-1), crystalline silica powder (d2), fused spherical silica powder (d3), fused spherical silica powder (d4), and An epoxy resin composition for sealing was produced in the same manner as in Example except that the addition amount of zinc borate (trade name FRC-150) was changed as shown in Table 1.

Example 9
Sealed in the same manner as in Example 1 except that the addition amount of phenoxyphosphazene (trade name SPE-100) was 0.50 parts and the addition amount of zinc borate (trade name FRC-150) was 4.0 parts. A stopping epoxy resin composition was produced.

(Comparative Example 1)
The addition amounts of crystalline silica powder (d1), crystalline silica powder (d2), fused spherical silica powder (d3) and fused spherical silica powder (d4) are 40.0 parts, 5.0 parts, 7.0 parts and A sealing epoxy resin composition was produced in the same manner as in Example 1 except that the amount was 6.0 parts.

(Comparative Example 2)
A sealing epoxy resin composition was produced in the same manner as in Example 1 except that the amount of crystalline silica powder (d2) added was changed to 10.0 parts.

(Comparative Example 3)
A sealing epoxy resin composition was produced in the same manner as in Example 1 except that the amount of the fused spherical silica powder (d3) added was 2.0 parts.

(Comparative Example 4)
The addition amounts of the fused spherical silica powder (d3) and the fused spherical silica powder (d4) are 5.5 parts and 2.0 parts, respectively, and the added quantity of zinc borate (trade name FRC-150) is 11.0. A sealing epoxy resin composition was produced in the same manner as in Example 1 except that the part was used.

(Comparative Example 5)
An epoxy resin composition for sealing was produced in the same manner as in Example 1 except that the addition amounts of the crystalline silica powder (d2) and the fused spherical silica powder (d3) were 5.0 parts and 13.0 parts, respectively. .

(Comparative Example 6)
The addition amount of the crystalline silica powder (d2) is 5.0 parts, the addition amount of the fused spherical silica powder (d4) is 13.0 parts, and the addition amount of zinc borate (trade name FRC-150) is 11. A sealing epoxy resin composition was produced in the same manner as in Example 1 except that the content was 0 part.

(Comparative Example 7)
Epoxy resin composition for sealing in the same manner as in Example 1 except that the addition amount of phenoxyphosphazene (trade name SPE-100) was 3.00 parts and zinc borate (trade name FRC-150) was not blended. The thing was manufactured.

(Comparative Example 8)
The addition amounts of crystalline silica powder (d1), crystalline silica powder (d2), fused spherical silica powder (d3) and fused spherical silica powder (d4) are 50.0 parts, 5.0 parts, 7.0 parts and Example except that the amount of addition of 6.0 parts, the amount of phenoxyphosphazene (trade name SPE-100) was 0.10 parts, and the amount of zinc borate (trade name FRC-150) was 20.0 parts. In the same manner as in Example 1, a sealing epoxy resin composition was produced.

(Comparative Example 9)
Epoxy for sealing in the same manner as in Example 1 except that 2-ethyl-4-methylimidazole (trade name: Curesol 2E4MZ, manufactured by Shikoku Kasei Co., Ltd.) was used instead of triphenylphosphine (trade name: PP-360). A resin composition was produced.

(Comparative Example 10)
o-cresol novolac type epoxy resin (trade name ESCN-190), phenol novolac resin (trade name H-1), crystalline silica powder (d1), crystalline silica powder (d2) fused spherical silica powder (d3), fused spherical silica An epoxy resin composition for sealing was produced in the same manner as in Example except that the addition amount of powder (d4) and zinc borate (trade name FRC-150) was changed as shown in Table 1.

  About the resin composition for sealing obtained by each said Example and each comparative example, various characteristics were evaluated by the method shown below. The results are shown in Table 1 and Table 2.

[Mold releasability]
The epoxy resin composition for sealing is molded with a mold heated to 175 ° C., and the load (mold release load) at the time of releasing from the mold is measured with a push-pull gauge. Evaluation based on the criteria. The mold used was a mirror-finished mold and a satin-finished mold.
○: Release load value of less than 40N Δ: Release load value of 40N or more and less than 50N ×: Release load value of 50N or more [spiral flow]
Using a spiral flow mold according to EMMI-1-66, the sealing epoxy resin composition was transfer molded under the conditions of a temperature of 175 ° C. and a pressure of 9.8 MPa, and the spiral flow was measured.
[Flow viscosity]
The flow viscosity at a temperature of 175 ° C. and a load pressure of 10 kgf / cm ² (about 0.98 MPa) was measured using a Koka flow tester (CFT-100, manufactured by Shimadzu Corporation).
[Slit burr]
Using a mold for slit burr measurement (thickness 10 μm and 20 μm, length 200 mm, width 8 mm slit), the sealing epoxy resin composition was subjected to conditions of a temperature of 175 ° C., an injection pressure of 7.0 MPa, and a curing time of 120 seconds. Then, the distance filled in the slit was measured and evaluated according to the following criteria.
○: Burr length less than 3 mm Δ: Burr length 3 mm or more and less than 5 mm ×: Burr length 5 mm or more [thermal conductivity]
The sealing epoxy resin composition was thermoformed at 175 ° C. for 8 hours to prepare a test piece having a diameter of 100 mm and a thickness of 25 mm. About this test piece, it measured using the rapid thermal conductivity measuring apparatus (Kyoto Electronics Industry Co., Ltd. product).

[Hot bending strength]
The sealing epoxy resin composition was transfer molded at 175 ° C. for 120 seconds, and then a test piece having a diameter of 100 mm and a thickness of 3.0 mm was prepared without post-curing. With respect to this test piece, the bending hardness at a temperature of 175 ° C. was measured using an Instron universal testing machine (measuring machine name 5942 manufactured by Instron) according to JIS K 6911.
[Flame retardance]
The epoxy resin composition for sealing was transfer molded at 175 ° C. for 120 seconds, and then post-cured at 175 ° C. for 8 hours to obtain a cured product of 12.7 mm × 1.27 mm × 0.8 mm, A combustion test based on the UL94 flame resistance test standard was conducted.
[Formability]
Using a 20-cavity mold (3-pin small semiconductor device: vertical 2.5 mm × horizontal 1.5 mm × height 0.5 mm), the sealing epoxy resin composition was heated to a temperature of 175 ° C. and an injection pressure of 7.0 MPa. Then, sealing molding was carried out under the condition of a curing time of 120 seconds, and the number of cracks or chippings observed by visual observation in the molded product when the mold was opened was counted. Similarly, the number (number of defects) of molded products that were not sufficiently filled with the epoxy resin composition for sealing on the back surface of the semiconductor device by visual observation was counted.

  As is apparent from Tables 1 and 2, the epoxy resin composition for sealing of the examples of the present invention, in particular, as a silica powder component, 70% by mass or more of crystalline silica powder having an average particle size of 10 to 30 μm and an average particle size of 3 10% by mass or less of crystalline silica powder less than 0.0 μm, 5 to 15% by mass of fused spherical silica powder having an average particle size of less than 3.0 μm, 5 to 15% by mass of fused spherical silica powder having an average particle size of 5 to 15 μm, and In an example using a silica powder having a mixing ratio (mass basis) of a fused spherical silica powder having an average particle size of less than 3.0 μm and a fused spherical silica powder having an average particle size of 5 to 15 μm of 0.75 to 1.25 It was found that the cured product strength characteristics and mold releasability were excellent and had good molding, as well as excellent flame retardancy and thermal conductivity.

Claims (6)

  (A) Cresol novolac type epoxy resin, (B) phenol novolac resin, (C) triphenylphosphine, (D) (d1) 70% by mass or more of crystalline silica powder having an average particle size of 10 to 30 μm, (d2) average particle size 10% by mass or less of crystalline silica powder less than 3.0 μm, (d3) 5 to 15% by mass of fused spherical silica powder having an average particle size of less than 3.0 μm, and (d4) fused spherical silica powder 5 having an average particle size of 5 to 15 μm A silica powder mixture comprising ˜15% by mass, (E) a phosphazene compound, and (F) a metal hydrate and / or a borate metal salt as essential components, and the ratio of the (D) silane powder mixture to the total composition is It is 70-85 mass%, The epoxy resin composition for sealing characterized by the above-mentioned.   (D) component is (d1) 70-75 mass% or more of crystalline silica powder with an average particle diameter of 10-30 μm, (d2) 5-10 mass% or less of crystalline silica powder with an average particle diameter of less than 3 μm, (d3) average particle 2. A silica powder mixture comprising 5 to 15% by mass of fused spherical silica powder having a diameter of less than 3 [mu] m and (d4) 5 to 15% by mass of fused spherical silica powder having an average particle size of 5 to 15 [mu] m. An epoxy resin composition for sealing.   (E) Content of a phosphazene compound is 0.1-3.0 mass% of the whole composition, The epoxy resin composition for sealing of Claim 1 or 2 characterized by the above-mentioned.   The epoxy for sealing according to any one of claims 1 to 3, wherein the content of (F) metal hydrate and / or metal borate is 5 to 15% by mass of the total composition. Resin composition.   In the component (D), the mass ratio (d3) / (d4) of (d3) fused spherical silica powder having an average particle size of less than 3.0 μm and (d4) fused spherical silica powder having an average particle size of 5 to 15 μm is 0. It is 75-1.25, The transparent resin composition of any one of the Claims 1 thru | or 4 characterized by the above-mentioned.   6. A semiconductor comprising a semiconductor element sealed with a cured product of the epoxy resin composition for sealing according to any one of claims 1 to 5, having a thermal conductivity of 2 W / m · K or more. apparatus.