JP2011058003A - Epoxy resin composition for sealing semiconductor, resin-sealed semiconductor device and method for mounting semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing a semiconductor corresponding to lead-free solder, giving a cured product having excellent solder crack resistance, high temperature stability and moisture resistance reliability; and to provide a semiconductor device using the composition and a method for mounting the device. <P>SOLUTION: The composition prepared by formulating (a) an epoxy resin, (b) an epoxy resin-curing agent and (c) an inorganic filler as essential components, and provides the cured product having a relative humidity of 85% at 85°C, moisture absorptivity of ≤0.2% for 72 hours and weight loss of ≤0.5% for 5 hours at 240°C in the air. The resin-sealed semiconductor device for mounting lead-free solder with use of the composition and the method for mounting the device are also provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lead-free solder mounting epoxy resin composition for semiconductor encapsulation that gives a cured product excellent in solder crack resistance, high-temperature stability, and moisture resistance reliability, and a resin seal suitable for high-temperature reflow using lead-free solder. The present invention relates to a mounting method for a semiconductor device having excellent mounting reliability using a lead-type semiconductor device and lead-free solder.

Epoxy resin compositions are used in a wide range of fields such as adhesion, casting, sealing, lamination, molding and painting because of their excellent cured properties and easy handling. In addition, there are many types of epoxy resin compositions and molding methods thereof, and the moldability and cured product properties vary greatly depending on the selection thereof, so that they are properly used depending on the purpose of the field of use.
In recent years, as the use conditions of polymer materials become severe, various properties required for polymer materials have become severe, and various commonly used resin compositions cannot sufficiently satisfy the required properties. It was.
For example, a composition in which an epoxy resin and a phenol resin curing agent are blended is widely used for semiconductor encapsulation, but the required performance is becoming strict in this field as well.
That is, surface mounting is the mainstream for mounting semiconductor devices on wiring boards. In surface mounting (solder reflow), the entire semiconductor device is exposed to a temperature higher than the melting temperature of the solder, so that moisture that has been absorbed rapidly expands, resulting in defects such as cracks in the sealing material. .
Furthermore, in recent years, there has been a movement to limit the use of harmful lead from the viewpoint of environmental protection, and lead-free solder has come to be used for mounting solder. Lead-free solder is solder containing conventional lead. It is necessary to have a higher melting temperature and a higher reflow temperature. For this reason, the epoxy resin composition for semiconductor encapsulation corresponding to lead-free solder mounting is required to have more severe solder crack resistance than conventional products. In addition, the novolac epoxy resins and phenols currently in use are also affected by the fact that a part of the cured resin is thermally decomposed due to high temperature, and the generated corrosive substance deteriorates the moisture resistance reliability of the internal semiconductor. Epoxy resin compositions for semiconductor encapsulation that contain a brominated epoxy resin as a flame retardant in a resin hardener cannot be used for lead-free solder mounting in terms of solder crack resistance, high-temperature stability, and moisture resistance reliability. It was.

  The present invention relates to a lead-free solder mounting epoxy resin composition for semiconductor encapsulation that gives a cured product excellent in solder crack resistance, high-temperature stability, and moisture resistance reliability, and a resin seal suitable for high-temperature reflow using lead-free solder. It is an object of the present invention to provide a mounting method for a semiconductor device having excellent mounting reliability using a stationary semiconductor device and lead-free solder.

As a result of various studies to solve the above-mentioned problems, the inventors of the present invention have achieved the object by using an epoxy resin composition in which the moisture absorption rate of the cured product and the weight reduction at high temperature holding are less than a specific amount. Was achieved. The present invention
“1. (a) Epoxy resin (b) Curing agent for epoxy resin (c) Inorganic filler is blended as an essential component, and the cured product has a relative humidity of 85% at 85 ° C. and a moisture absorption rate at 72 hours. An epoxy resin composition for semiconductor encapsulation corresponding to lead-free solder mounting, which is 0.2% or less and the weight loss after 5 hours in air at 240 ° C. is 0.5% or less.
2. Item 1. The epoxy resin composition for semiconductor encapsulation according to Item 1, wherein the component (a) and the component (b) are used in combination with a combination in which the mixture has a melt viscosity of 1.0 poise or less at 150 ° C.
3. A curing agent having a group that reacts with an epoxy group is used as the component (b), and the total number of groups that react with the epoxy group in the component (b) is 0 with respect to 1 mol of the epoxy group in the component (a). The epoxy resin composition for semiconductor encapsulation corresponding to lead-free solder mounting described in the item 1 or 2, which is 0.5 to 2.0 mol.
4). Item (1) or Item (2), wherein a curing agent that initiates polymerization of an epoxy group is used as component (b), and 0.1 to 10 parts by weight of component (b) is used with respect to 100 parts by weight of component (a). The epoxy resin composition for semiconductor encapsulation corresponding to lead-free solder mounting.
5. (C) The epoxy resin for semiconductor encapsulation according to any one of items 1 to 4, which contains 80 to 95% by weight of a fused and / or crystalline silica powder filler as an inorganic filler, based on the total composition. Composition.
6). The halogen element content is 0.5% by weight or less based on the total amount of the component (a) and the component (b), and the cured product has flame retardancy equivalent to V-0 of UL94 standard, 6. An epoxy resin composition for encapsulating a semiconductor according to any one of items 1 to 5.
7). A resin-encapsulated lead-free solder mounting type in which a semiconductor element and / or a semiconductor integrated circuit is encapsulated with a cured product of the epoxy resin composition for encapsulating a semiconductor according to any one of items 1 to 6 Semiconductor device.
8). A method of mounting a semiconductor device, characterized by soldering and mounting the resin-encapsulated semiconductor device described in item 7 on a wiring board using solder that does not substantially contain lead and has a melting temperature of 200 ° C. or higher. "
About.

  The epoxy resin composition for semiconductor encapsulation of the present invention provides a cured product excellent in solder crack resistance, high-temperature stability and moisture resistance reliability, so that it can be advantageously used for sealing a semiconductor device compatible with lead-free solder mounting. it can. Since the resin-encapsulated semiconductor device of the present invention is excellent in solder crack resistance, high-temperature stability, and moisture resistance reliability, it can be advantageously used for mounting using lead-free solder. Since the mounting method of the semiconductor device of the present invention is excellent in mounting reliability, it can be advantageously used for mounting using lead-free solder.

In the mounting method using lead-free solder with a high melting temperature, it is necessary to increase the reflow temperature. However, in the conventional epoxy resin composition for semiconductor encapsulation, moisture absorbed during storage is high due to its high moisture absorption rate. When the material is exposed to a high temperature, it rapidly expands, and as a result, defects such as cracks in the sealing material are likely to occur. In addition, since brominated epoxy resins with poor thermal stability are blended, they are thermally decomposed at high temperatures, corrosive substances such as halogen compounds are generated, and the moisture resistance reliability of internal semiconductors deteriorates. There is also.
In the present invention, high-temperature reflow using lead-free solder is performed by blending a large amount of silica filler into a low melt viscosity resin system, reducing moisture absorption, and not blending components with poor thermal stability. Even so, solder cracks are less likely to occur, and the reliability of moisture resistance is greatly improved.

Examples of the (a) epoxy resin used in the epoxy resin composition for semiconductor encapsulation of the present invention include bisphenol A, bisphenol F, bisphenol AD, biphenol, tetramethylbiphenol, tetramethylbisphenol F, hydroquinone, methylhydroquinone, and dibutylhydroquinone. , Resorcin, methylresorcin, dihydroxydiphenyl ether, dihydrokistilbene derivatives, dihydroxynaphthalene, phenol novolac resin, cresol novolac resin, naphthol novolac resin, bisphenol A novolac resin, phenol aralkyl resin, terpene phenol resin, dicyclopentadiene phenol resin; Phenols, benzaldehyde, hydroxybenzaldehyde, croton aldehyde , Polyhydric phenol resins obtained by condensation reactions with various aldehydes such as glyoxal; various phenols such as modified phenol resins obtained by polycondensation reaction of heavy oils or pitches, phenols and aldehyde compounds Epoxy resins produced from epoxy compounds and epihalohydrins, various amine compounds such as diaminodiphenylmethane, aminophenol and xylenediamine, and epoxy resins produced from epihalohydrins, methylhexahydroxyphthalic acid, dimer acids, etc. Hydrogenated epoxy resins such as epoxy resins produced from carboxylic acids and epihalohydrins, hydrogenated bisphenol A type epoxy resins, hydrogenated bisphenol F type epoxy resins, 1,2-epoxyethyl-3,4-epoxycyclohexane, 3 , - epoxycyclohexyl carboxylate-3,4-epoxy cyclohexylmethyl, alicyclic epoxy resins such as adipic acid bis (3,4-epoxy-6-methylcyclohexyl methyl> and the like.
These epoxy resins may be used individually by 1 type, and may be used in mixture of 2 or more types.
Among various epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenol type epoxy resin, tetramethylbiphenol type epoxy resin, phenol novolac type epoxy resin, cresol novolac type due to availability and cured properties At least one epoxy resin selected from an epoxy resin, a bisphenol A novolac type epoxy resin, a terpene phenol type epoxy resin, and a dicyclopentadiene phenol type epoxy resin is preferable.

Next, (b) a curing agent for epoxy resin is blended as an essential component in the epoxy resin composition for semiconductor encapsulation of the present invention.
Examples of the curing agent that can be used include bisphenol A, bisphenol F, bisphenol AD, hydroquinone, resorcin, methylresorcin, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, phenol novolac resin, cresol novolac resin, bisphenol A novolac resin. Condensation reaction of various polyphenol resins such as dicyclopentadiene phenol resin, terpene phenol resin, naphthol novolak resin, biphenyl phenol resin, and various phenols with various aldehydes such as hydroxybenzaldehyde, crotonaldehyde, and glyoxal Polyhydric phenol resin obtained from the above and heavy oils or pitches, phenols and formaldehyde Various phenolic resins such as modified phenolic resins obtained by polycondensation of hydride compounds, acid anhydrides such as methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, methylnadic acid, diethylenetriamine, isophorone Examples include amines such as diamine, diaminodiphenylmethane, diaminodiphenylsulfone, and dicyandiamide.

Examples of the curing agent that initiates polymerization of epoxy groups include phosphine compounds such as triphenylphosphine, phosphonium salts such as tetraphenylphosphonium tetraphenylborate, 2-methylimidazole, 2-phenylimidazole, and 2-ethyl. Imidazoles such as -4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6- [2-methylimidazolyl- (1)]-ethyl-S-triazine, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-methylimidazolium isocyanurate, 2-ethyl-4-methylimidazolium tetraphenylborate, 2-ethyl-1,4-dimethylimidazolium tetraphenylborate, etc. No Dazolium salts, amines such as 2,4,6-tris (dimethylaminomethyl) phenol, benzylmethylamine, ammonium salts such as triethylammonium tetraphenylborate, 1,5-diazabicyclo (5,4,0) -7- Undecene, diazabicyclo compounds such as 1,5-diazabicyclo (4,3,0) -5-nonene, tetraphenylborate, phenol salt, phenol novolak salt, 2-ethylhexanoate and the like of these diazabicyclo compounds, and triflic acid (Triflic acid) salt, boron trifluoride ether complex compound, metal fluoroboron complex salt, bis (perfluoroalkylsulfonyl) methane metal salt, aryldiazonium compound, aromatic onium salt, dicarbonyl chelate of group IIIa to Va element, Thiopyrylium salt MF6 ^- form of VIb element anions (here chosen phosphorous, antimony and arsenic), arylsulfonium complex salts, aromatic iodonium complex salts, aromatic sulfonium complex salt, bis [4- (diphenylsulfonio) phenyl] sulfide - Bis-hexafluorometal salts (eg, phosphates, arsenates, antimonates, etc.), arylsulfonium complex salts, aromatic sulfonium or iodonium salts of halogen-containing complex ions, and the like can be used.
The epoxy resin curing agent (b) may be used alone or in combination of two or more.
Among these curing agents for epoxy resins, phenol novolac resins, terpene phenol resins, phenol aralkyl resins, dicyclopentadiene phenol resins, biphenyl phenol resins, heavy oils or pitches, phenols and aldehyde compounds are subjected to a polycondensation reaction. The modified phenolic resin obtained in this way is preferable from the viewpoints of cured physical properties and availability.

The use ratio of the component (b) used in the epoxy resin composition for semiconductor encapsulation of the present invention is the total component (a) when only a compound having a group that reacts with an epoxy group is used as the component (b). The total amount of the groups that react with the epoxy groups in the component (b) is preferably 0.5 to 2.0 mol, more preferably 0.7 to 1. The amount is 5 mol.
(B) When using the hardening | curing agent of the type which starts the superposition | polymerization of an epoxy group as a component, 0.1-10 weight part is preferable with respect to 100 weight part of all the (a) components, More preferably, it is 0.00. 3 to 5 parts by weight.
The epoxy resin composition for semiconductor encapsulation of the present invention has a relative humidity of 85% at 85 ° C. and a moisture absorption rate at 72 hours of 0.2% or less in order to prevent solder cracks during high reflow using lead-free solder. And preferably 0.15% or less.
If the moisture absorption rate is high, cracks are likely to occur at high temperatures, which is not desirable. To maintain reliability after reflow at a high temperature using lead-free solder, the weight after holding in air at 240 ° C. for 5 hours The reduction needs to be 0.5% or less, preferably 0.3% or less.

In the epoxy resin composition for semiconductor encapsulation of the present invention, it is necessary to blend a large amount of silica filler in order to reduce the moisture absorption rate. For this purpose, it is necessary to lower the melt viscosity of the resin system (mixture of the components (a) and (b)), and the melt viscosity at 150 ° C. is preferably 1.0 poise or less, more preferably 0. The type and mixing ratio of each of the component (a) and the component (b) must be adjusted so that they are 0.8 poise or less, more preferably 0.6 poise or less. If the melt viscosity of the resin system is too high, the flowability of the epoxy resin composition is lowered and molding becomes difficult.
Next, (c) inorganic filler is mix | blended with the epoxy resin composition for semiconductor sealing of this invention. Examples of the inorganic filler include fused silica, crystalline silica, glass powder, alumina, calcium carbonate, and the like. Its shape is crushing or spherical. Various inorganic fillers may be used alone or in combination of two or more. Among them, fused silica or crystalline silica is preferable. The amount used is 80 to 95% by weight of the total composition, preferably 85 to 95% by weight, and more preferably 87 to 93% by weight. (C) When there is too little usage-amount of an inorganic filler, it is inferior to low hygroscopicity, and is inferior to solder crack resistance as a result. (C) When there is too much usage-amount of an inorganic filler, the fluidity | liquidity at the time of shaping | molding will be impaired.
If necessary, the epoxy resin composition of the present invention includes a curing accelerator, a flame retardant, a flame retardant aid, a coupling agent, an ion scavenger, a plasticizer, a pigment, a solvent, a release agent, a reinforcing fiber, and the like. Can be blended appropriately.

The curing accelerator is a compound that promotes the reaction between the epoxy group in the epoxy resin and the active group in the curing agent, and a phosphine compound such as tributylphosphine and triphenylphosphine, and a phosphonium salt such as tetraphenylphosphonium tetraphenylborate. , Imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, amines such as 2,4,6-tris (dimethylaminomethyl) phenol, benzyldimethylamine, triethylammonium tetraphenyl Ammonium salts such as borate, diazabicyclo compounds such as 1,5-diazabicyclo (5,4,0) -7-undecene, tetraphenylborate, phenol salt, phenol novolac salt of these diazabicyclo compounds, 2 Such as ethylhexanoic acid salts.
In general, since epoxy resin compositions for semiconductor encapsulation are required to impart flame retardancy, halogen compounds such as brominated epoxy resins are often added as flame retardants. However, it is preferable not to add a halogen-based flame retardant, because halogen ions and the like are generated by thermal decomposition at a high temperature during reflow using lead-free solder and adversely affect electrical characteristics. Although the halogen element may be brought in as an impurity in the raw material, the total amount of the component (a) and the component (b) including the amount thereof is preferably 0.5% by weight or less, more preferably 0%. .3% by weight or less, more preferably 0.1% by weight or less. Since the flame retardancy of the cured product is obligated by the standards of electrical and electronic parts and equipment, it must have flame retardancy equivalent to UL94 standard V-0 or higher.

Instead of halogen flame retardants, phosphorus flame retardants such as phosphate esters and phosphines, nitrogen flame retardants such as melamine derivatives, and inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide can be used. However, since these substances also generate corrosive substances at high temperatures and deteriorate the hygroscopicity, it is preferable not to use them or to minimize them.
The flame retardancy of the epoxy resin composition varies greatly depending on the type and blending ratio of the epoxy resin, the curing agent, the inorganic filler, and other additives. In the epoxy resin composition for semiconductor encapsulation of the present invention, it is necessary to adjust the types and blending ratios of the respective components so that the necessary flame retardance is exhibited while maintaining the moisture absorption rate and weight reduction below the predetermined values. There is.

In the resin-encapsulated semiconductor device of the present invention, a semiconductor element such as an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, or a diode and / or a semiconductor integrated circuit is a cured product of the epoxy resin composition for semiconductor encapsulation of the present invention. It is a sealed resin semiconductor device for lead-free solder mounting, and is not particularly limited to the type of semiconductor element and / or semiconductor integrated circuit, sealing method, package shape, and the like.
The sealing method includes low-pressure transfer molding method using a solid epoxy resin composition at room temperature, injection molding method, potting method using a liquid epoxy resin composition at room temperature, screen printing method, underfill method, etc. Certain curing conditions after molding vary depending on the types and blending amounts of the components of the epoxy resin composition, but are usually from 30 seconds to 10 hours at a temperature of 150 to 220 ° C.
The package shape of the resin-encapsulated semiconductor device is a lead frame type such as DIP, ZIP, SOP, SOJ, and QFP, a single-side encapsulated type such as BGA, TAB, and CSP.

The semiconductor device mounting method of the present invention is a semiconductor device mounting method characterized by soldering and mounting the resin-encapsulated semiconductor device of the present invention on a wiring board using lead-free solder.
Lead-free solders used in the mounting method of the present invention are Sn-Ag, Sn-Ag-Cu, Sn-Ag-Bi, Sn-Bi, Sn-Bi-Ag-Cu, Sn-Cu. Solder that does not substantially contain lead, such as a Sn-Zn-based or Sn-Zn-Bi-based solder, and their melting temperature is generally 200 ° C. or higher.
The reflow method includes infrared reflow, solder bath dip, vapor phase reflow, hot air reflow, and the like, and the heating temperature needs to be 30 to 60 ° C. higher than the melting temperature of the solder.
The epoxy resin composition for semiconductor encapsulation of the present invention provides a cured product excellent in solder crack resistance, high-temperature stability and moisture resistance reliability, so that it can be advantageously used for sealing a semiconductor device compatible with lead-free solder mounting. Since the resin-encapsulated semiconductor device of the present invention is excellent in solder crack resistance, high temperature stability and moisture resistance reliability, it can be advantageously used for mounting using lead-free solder. Since the mounting method of the semiconductor device of the present invention is excellent in mounting reliability, it can be advantageously used for mounting using lead-free solder.

Hereinafter, the epoxy resin composition for semiconductor encapsulation, the resin-encapsulated semiconductor device, and the method for mounting the semiconductor device of the present invention will be described in further detail with reference to examples and comparative examples.
Examples 1-5 and Comparative Examples 1 and 2
As shown in Table 1, (a) cresol novolac type epoxy resin, tetramethylbiphenol type epoxy resin or bisphenol type epoxy resin as epoxy resin, and brominated bisphenol A type epoxy resin as flame retardant, (b) epoxy resin Phenol aralkyl resin, phenol novolac resin, or heavy oils or pitches, modified phenol resin obtained by polycondensation reaction with phenols and aldehyde compound, (c) spherical fused silica as inorganic filler Each semiconductor sealing epoxy resin composition was blended using powder, triphenylphosphine as a curing accelerator, antimony trioxide as a flame retardant aid, carnauba wax as a release agent, and epoxysilane as a silane coupling agent. Subsequently, each compound was melt-mixed at a temperature of 70 to 130 ° C. for 5 minutes using a mixing roll, and each obtained melt mixture was taken out into a sheet and pulverized to obtain each molding material.
Each of these molding materials was molded with a low-pressure transfer molding machine at a mold temperature of 180 ° C. and a molding time of 90 seconds to obtain each test piece and a 160-pin TQFP-type resin-encapsulated semiconductor device. Post cure. Table 1 shows the results of testing the moisture absorption rate, weight loss, and flame retardancy of each molding material after post-curing.
Further, each resin-encapsulated semiconductor device was mounted on a wiring board by infrared reflow at 260 ° C. using Sn—Ag—Cu-based lead-free solder (melting temperature: 220 ° C.). The results of testing the solder crack resistance after mounting and the moisture resistance reliability are also shown in Table 1, and each composition of Examples 1 to 5 is more resistant to solder cracking and moisture than the compositions of Comparative Examples 1 and 2. The balance of reliability was excellent.

(註)
* 1: A; Tetramethylbiphenol type epoxy resin (Oilized Shell Epoxy, trade name: Epicoat YX4000H, epoxy equivalent: 193)
* 2: B: Mixture of tetramethylbiphenol type epoxy resin and biphenol type epoxy resin (Oilized Shell Epoxy, trade name: Epicoat YL6121H, epoxy equivalent: 171)
* 3: C: Mixture of orthocresol novolac type epoxy resin and biphenol type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd., Epicoat YL6640, epoxy equivalent: 193)
* 4: D: Orthocresol novolac type epoxy resin (Oilized Shell Epoxy Corporation, trade name: Picoat 180S65, epoxy equivalent: 212)
* 5: Brominated bisphenol A type epoxy resin (Oilized Shell Epoxy product name Epicoat 5050, epoxy equivalent: 385, bromine content: 49%)
* 6: E; phenol novolac resin (manufactured by Gunei Chemical Co., hydroxyl equivalent: 105)
* 7: F: Phenol aralkyl resin (trade name: Mitex XL225-3L, hydroxyl equivalent: 170, Mitsui Chemicals)
* 8 * G: Modified phenol resin obtained by polycondensation reaction of heavy oils or pitches, phenols and aldehyde compounds (trade name: FPI5167, hydroxyl equivalent: 165, Kashima Oil Co., Ltd.)
* 9: Melt viscosity of the mixture at the use ratio of component (a) and component (b) * 10: Calculated from the halogen content of each raw material * 11: Spherical fused silica powder (Nippon Aerosil Co., Ltd., trade name ERISL BF100)
* 12: Epoxy silane (trade name KBM-403, Shin-Etsu Chemical Co., Ltd.)
* 13: 85 ° C, 85% RH Hygroscopicity after 72 hours * 14: Weight loss after holding in 240 ° C air for 5 hours * 15: Measured according to UL-94 * 16: 85 160 ° C TQFP 16 pieces After absorbing moisture for 168 hours at 85% RH, 260 ° C. infrared reflow was performed to determine the number of cracks.
* 17: An unsaturated PCT bias test (130 ° C., 85% RH V = 50 V) was performed on the 160-pin TQFP after mounting, and the average failure life was obtained.

Claims (8)

(A) Epoxy resin (b) Curing agent for epoxy resin (c) An inorganic filler is blended as an essential component, and the cured product has a relative humidity of 85% at 85 ° C. and a moisture absorption rate at 72 hours of 0.2%. % Epoxy resin composition for lead-free solder mounting that is less than 0.5% and the weight loss in air at 240 ° C. for 5 hours is 0.5% or less. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the component (a) and the component (b) are used in combination with a combination in which the mixture has a melt viscosity at 150 ° C. of 1.0 poise or less. A curing agent having a group that reacts with an epoxy group is used as the component (b), and the total number of groups that react with the epoxy group in the component (b) is 0 with respect to 1 mol of the epoxy group in the component (a). The epoxy resin composition for semiconductor encapsulation corresponding to lead-free solder mounting according to claim 1 or 2, which is 0.5 to 2.0 mol. The hardener which starts superposition | polymerization of an epoxy group is used as (b) component, and 0.1-10 weight part of (b) component was used with respect to 100 weight part of all (a) components, The claim 1 or 2 The epoxy resin composition for semiconductor encapsulation corresponding to lead-free solder mounting. (C) The epoxy resin for semiconductor encapsulation according to any one of claims 1 to 4, which contains 80 to 95% by weight of a fused and / or crystalline silica powder filler as an inorganic filler based on the total composition. Composition.   The halogen element content is 0.5% by weight or less based on the total amount of the component (a) and the component (b), and the cured product has flame retardancy equivalent to V-0 of UL94 standard, The semiconductor sealing type epoxy resin composition described in any one of Claims 1 thru | or 5.   A resin-encapsulated type for mounting lead-free solder, wherein the semiconductor element and / or the semiconductor integrated circuit is encapsulated with a cured product of the epoxy resin composition for encapsulating a semiconductor according to any one of claims 1 to 6. Semiconductor device. A method of mounting a semiconductor device, characterized by soldering and mounting the resin-encapsulated semiconductor device according to claim 7 on a wiring board using solder that does not substantially contain lead and has a melting temperature of 200 ° C. or higher. .