JP2008031326A - Epoxy resin composition for semiconductor encapsulation and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for semiconductor encapsulation that has good flowability, curability, mold release characteristics and continuous moldability during encapsulation forming, and has good solder resistance without causing peeling and cracks upon solder treatment at an elevated temperature meeting lead-free soldering. <P>SOLUTION: This epoxy resin composition for semiconductor encapsulation comprises an epoxy resin (A), a phenolic resin curing agent (B), an inorganic filler (C), a curing accelerator (D) and a release agent (E), wherein the curing accelerator (D) comprises a curing accelerator (d1) having a cation moiety and a silicate anion moiety, and the release agent (E) comprises an oxidized polyethylene wax (e1). The semiconductor device encapsulating the semiconductor by use of the resin composition is also disclosed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition for semiconductor encapsulation and a semiconductor device using the same.

As a sealing method for semiconductor elements such as IC and LSI (hereinafter also referred to as “chips”), transfer molding of an epoxy resin composition is suitable for low-cost, mass production, and has been used for a long time. However, the improvement of the property has been achieved by improving the epoxy resin and the phenol resin which is a curing agent. However, in recent years, electronic devices have become smaller, lighter, and higher in performance, and semiconductors have been increasingly integrated, and the surface mounting of semiconductor devices (hereinafter also referred to as “packages”) has been promoted. In particular, the demand for epoxy resin compositions for semiconductor encapsulation has become increasingly severe. For this reason, the problem which cannot be solved with the conventional epoxy resin composition has also come out.
The biggest problem is that by adopting surface mounting, the semiconductor device is suddenly exposed to a high temperature of 200 ° C. or higher in the solder dipping or soldering process, and the moisture when moisture absorbed explosively evaporates. In particular, a phenomenon in which reliability is remarkably reduced due to peeling at the interface between various plated joints such as gold plating and silver plating on semiconductor elements, lead frames, and inner leads and the cured product of the epoxy resin composition. It is. In addition, with the shift from leaded solder to lead-free solder, which originated from environmental problems, the temperature during the soldering process increased, and the solder resistance due to explosive stress generated by the evaporation of moisture contained in the semiconductor device However, it has become a bigger problem than before.

  For such a problem, by applying a low water-absorbing epoxy resin or a curing agent to improve solder heat resistance (for example, refer to Patent Documents 1, 2, and 3), the mounting temperature rises. The correspondence has come to come. On the other hand, the epoxy resin composition exhibiting such low water absorption and low elastic modulus has a low crosslinking density, and the molded product immediately after curing is soft, and in continuous production, there is a problem in moldability such as resin tray on the mold. There was a problem of lowering productivity.

  As an effort to improve productivity, which is the above problem, application of a release agent having a high release effect has been proposed (see, for example, Patent Document 4), but a decrease in resin components accompanying an increase in inorganic fillers. As a result, there are problems with poor mold releasability, which is thought to be due to insufficient dispersibility of the mold release agent components, resin trays on the mold, and poor appearance of molded products. In particular, mold release agents with a high mold release effect are inevitable. In particular, the surface of the molded product is easily raised, and there is a drawback that the appearance of the molded product is markedly soiled when continuously produced. Therefore, even if the blending amount of the inorganic filler is increased, the flowability and filling property at the time of molding are not impaired, it is possible to cope with problems such as continuous moldability, appearance of the molded product, mold contamination, and the semiconductor device. There is a need for further technology that can satisfy reliability.

Japanese Patent Laid-Open No. 9-3161 JP 9-235353 A JP-A-11-140277 JP 2002-220434 A

  The present invention has good fluidity, curability, mold release and continuous formability at the time of sealing molding, and good solder resistance that does not cause peeling or cracking even by high-temperature solder processing corresponding to lead-free solder. The present invention provides a semiconductor sealing epoxy resin composition having high reliability and a highly reliable semiconductor device.

The present invention
[1] In the epoxy resin composition comprising (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) an inorganic filler, (D) a curing accelerator, and (E) a release agent, the curing acceleration An epoxy resin for semiconductor encapsulation, wherein the agent (D) contains a curing accelerator (d1) having a cation part and a silicate anion part, and the release agent (E) contains an oxidized polyethylene wax (e1) Composition,
[2] The epoxy resin composition for semiconductor encapsulation according to item [1], wherein the cation part of the curing accelerator (d1) having the cation part and the silicate anion part contains a phosphorus cation.

（ただし、上記一般式（１）において、Ｒ¹、Ｒ²、Ｒ³及びＲ⁴は、それぞれ、芳香環又は複素環を有する有機基、あるいは脂肪族基を表し、互いに同一であっても異なっていてもよい。Ｘ¹は、基Ｙ¹及びＹ²と結合する有機基である。Ｘ²は、基Ｙ³及びＹ⁴と結合する有機基である。Ｙ¹及びＹ²はプロトン供与性置換基がプロトンを放出してなる基であり、同一分子内の基Ｙ¹、及びＹ²が珪素原子と結合してキレート構造を形成するものである。Ｙ³及びＹ⁴はプロトン供与性置換基がプロトンを放出してなる基であり、同一分子内の基Ｙ³及びＹ⁴が珪素原子と結合してキレート構造を形成するものである。Ｘ¹、及びＸ²は互いに同一であっても異なっていてもよく、Ｙ¹、Ｙ²、Ｙ³、及びＹ⁴は互いに同一であっても異なっていてもよい。Ｚ¹は芳香環又は複素環を有する有機基、あるいは脂肪族基を表す。） [3] The semiconductor encapsulation according to item [1] or [2], wherein the curing accelerator (d1) having the cation part and the silicate anion part is a compound represented by the following general formula (1): Epoxy resin composition for

(In the above general formula (1), R ¹ , R ² , R ³ and R ⁴ each represents an organic group or an aliphatic group having an aromatic ring or a heterocyclic ring, and they may be the same or different from each other. X ¹ is an organic group bonded to the groups Y ¹ and Y ^2. X ² is an organic group bonded to the groups Y ³ and Y ^4. Y ¹ and Y ² are proton donating groups. The substituent is a group formed by releasing a proton, and the groups Y ¹ and Y ² in the same molecule are bonded to a silicon atom to form a chelate structure, and Y ³ and Y ⁴ are proton-donating substitutions. The group is a group formed by releasing a proton, and the groups Y ³ and Y ⁴ in the same molecule are bonded to a silicon atom to form a chelate structure, and X ¹ and X ² are the same as each other. Y ¹ , Y ² , Y ³ , and Y ⁴ may be the same or different from each other. Z ¹ represents an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group.)

[4] The epoxy resin composition for semiconductor encapsulation according to any one of [1] to [3], wherein the dropping point of the oxidized polyethylene wax (e1) is 100 ° C. or higher and 140 ° C. or lower.
[5] The average particle diameter of the oxidized polyethylene wax (e1) is 20 μm or more and 70 μm or less, and the content ratio of particles having a particle diameter of 106 μm or more in the total oxidized polyethylene wax (e1) is 0.1% by weight or less. The epoxy resin composition for semiconductor encapsulation according to any one of items [1] to [4],
[6] The epoxy resin composition for semiconductor encapsulation according to any one of [1] to [5], wherein the acid value of the oxidized polyethylene wax (e1) is 10 mgKOH / g or more and 50 mgKOH / g or less. ,
[7] The epoxy resin composition for semiconductor encapsulation according to any one of [1] to [6], wherein the oxidized polyethylene wax (e1) has a number average molecular weight of 500 or more and 5000 or less.
[8] The semiconductor encapsulation according to any one of items [1] to [7], wherein the density of the oxidized polyethylene wax (e1) is 0.94 g / cm ³ or more and 1.03 g / cm ³ or less. Epoxy resin composition for
[9] Polyethylene wax oxide (e11) produced by low-pressure polymerization method using oxidized polyethylene wax (e1), polyethylene wax oxide (e12) produced by high-pressure polymerization method, and oxidation of high-density polyethylene polymer The epoxy resin composition for semiconductor encapsulation according to any one of items [1] to [8], which is at least one selected from the product (e13),
[10] A semiconductor device comprising a semiconductor element sealed using the epoxy resin composition for semiconductor sealing according to any one of [1] to [9],
It is.

  According to the present invention, peeling and cracking are generated even at high temperature soldering treatment corresponding to lead-free solder having good fluidity, curability, releasability, and continuous formability during sealing molding of semiconductor elements and the like. Thus, an epoxy resin composition for semiconductor encapsulation having good solder resistance is obtained.

The present invention includes an epoxy resin, a phenol resin-based curing agent, an inorganic filler, a curing accelerator having a cation portion and a silicate anion portion, and a mold release agent containing oxidized polyethylene wax. An epoxy resin composition for semiconductor encapsulation having excellent fluidity, curability, releasability, and continuous moldability and excellent solder resistance can be obtained.
Hereinafter, the present invention will be described in detail.

  The epoxy resin (A) used in the present invention is a monomer, oligomer, or polymer in general having two or more epoxy groups in one molecule, and its molecular weight and molecular structure are not particularly limited. Epoxy resin, bisphenol type epoxy resin, stilbene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenolmethane type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene Modified phenol type epoxy resin, phenol aralkyl type epoxy resin (having phenylene skeleton, biphenylene skeleton, etc.), sulfur atom containing type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, naphthol Aralkyl type epoxy resin (phenylene skeleton, a biphenylene having a skeleton or the like), and the like. These may be used in combination of two or more be used one kind alone. Among these, from the viewpoint of solder resistance and flame resistance, a phenol aralkyl type epoxy resin containing a biphenylene skeleton is preferable.

  The phenol resin-based curing agent (B) used in the present invention is a monomer, oligomer or polymer in general having two or more phenolic hydroxyl groups in one molecule, and its molecular weight and molecular structure are not particularly limited. For example, phenol novolac resin, cresol novolak resin, dicyclopentadiene modified phenol resin, terpene modified phenol resin, triphenolmethane type resin, phenol aralkyl resin (having phenylene skeleton, biphenylene skeleton, etc.), sulfur atom containing type phenol resin, naphthol novolak Examples thereof include resins and naphthol aralkyl resins (having a phenylene skeleton, a biphenylene skeleton, etc.), and these may be used alone or in combination of two or more. Among these, from the viewpoint of solder resistance and flame resistance, a phenol aralkyl resin containing a biphenylene skeleton is preferable.

  The blending amount of the epoxy resin (A) and the phenol resin curing agent (B) used in the present invention is the ratio of the number of epoxy groups (EP) of all epoxy resins and the number of phenolic hydroxyl groups (OH) of all phenol resin curing agents. (EP / OH) is preferably 0.7 or more and 1.3 or less. Within this range, a decrease in curability of the epoxy resin composition, a decrease in glass transition temperature of the cured product, a decrease in moisture resistance reliability, and the like can be suppressed.

As an inorganic filler (C) used for this invention, what is generally used for the epoxy resin composition for semiconductor sealing can be used. For example, fused silica, crystalline silica, talc, alumina, silicon nitride and the like can be mentioned, and the most suitably used is spherical fused silica. These inorganic fillers (C) may be used alone or in combination. The maximum particle size of the inorganic filler (C) is not particularly limited, but considering the prevention of problems such as wire flow caused by the coarse particles of the inorganic filler (C) being sandwiched between the narrowed wires, 105 μm Or less, and more preferably 75 μm or less.
Although content of an inorganic filler (C) is not specifically limited, 80 weight% or more and 94 weight% or less are preferable in all the epoxy resin compositions. Within this range, a decrease in solder resistance, a decrease in fluidity, and the like can be suppressed.

The curing accelerator (D) used in the present invention is a curing accelerator (d1) having a cation part that can accelerate the curing reaction of the epoxy resin and a silicate anion part that suppresses the catalytic activity of the cation part that accelerates the curing reaction. ) (Hereinafter also simply referred to as “curing accelerator (d1)”). Since the curing accelerator (d1) does not easily start and accelerate the curing reaction at a temperature lower than the molding temperature of the epoxy resin (A) and the phenol resin-based curing agent (B), fluidity and storage stability. It is possible to impart excellent characteristics to the above. In addition, the curing accelerator (d1) can be imparted with excellent curability at the same time in addition to the above properties because the cation portion is easily liberated in the molding temperature range to promote the curing reaction. It is. As a hardening accelerator (d1) which has a cation part and a silicate anion part, what a cation part contains a phosphorus cation is preferable, and the compound represented by following General formula (1) is more preferable.

In the general formula (1), R ¹ , R ² , R ³ and R ⁴ each represents an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group, and may be the same or different from each other. Good. Examples of R ¹ , R ² , R ³ and R ⁴ include phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, naphthyl group, hydroxynaphthyl group, benzyl group, methyl group, ethyl group, and n-butyl. Group, n-octyl group, cyclohexyl group and the like. Among these, aromatic groups such as phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group and hydroxynaphthyl group are more preferable.

In the general formula (1), X ¹ is an organic group bonded to group Y ¹ and Y ^2. Similarly, X ² is an organic group bonded to the groups Y ³ and Y ⁴ . Y ¹ and Y ² are groups formed by proton-donating substituents releasing protons, and groups Y ¹ and Y ² in the same molecule are bonded to a silicon atom to form a chelate structure. Similarly, Y ³ and Y ⁴ are groups formed by proton-donating substituents releasing protons, and groups Y ³ and Y ⁴ in the same molecule are combined with a silicon atom to form a chelate structure. X ¹ and X ² may be the same or different from each other, and Y ¹ , Y ² , Y ³ , and Y ⁴ may be the same or different from each other. Such a group represented by Y ¹ X ¹ Y ² and Y ³ X ² Y ⁴ in the general formula (1) is composed of a group formed by releasing two protons from a divalent or higher proton donor. Examples of divalent or higher proton donors include catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,2′-biphenol, 2,2′-binaphthol, Salicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chloranilic acid, tannic acid, 2-hydroxybenzyl alcohol, 1,2-cyclohexanediol, 1,2-propanediol, glycerin, etc. Among these, catechol, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene are more preferable.

Z ¹ in the general formula (1) represents an organic group or an aliphatic group having an aromatic ring or a heterocyclic ring, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, Aliphatic hydrocarbon groups such as hexyl group and octyl group, aromatic hydrocarbon groups such as phenyl group, benzyl group, naphthyl group and biphenyl group, glycidyloxypropyl group, mercaptopropyl group, aminopropyl group and vinyl group Although a reactive substituent etc. are mentioned, Among these, a methyl group, an ethyl group, a phenyl group, a naphthyl group, and a biphenyl group are more preferable from the surface of thermal stability.

  Although the compounding quantity of the hardening accelerator (d1) which has a cation part and a silicate anion part used by this invention is not specifically limited, 0.1 weight% or more and 1.5 weight% or less are in all the epoxy resin compositions. Desirably, more preferably 0.2% by weight or more and 1% by weight or less. Within the above range, the viscosity of the epoxy resin composition can be lowered, the fluidity can be increased, and the storage stability during storage can be improved.

  In the present invention, as long as the effect of using the curing accelerator (d1) having a cation part and a silicate anion part is not impaired, a curing accelerator other than the curing accelerator (d1) may be an epoxy group and a phenol. As long as it promotes the reaction of the reactive hydroxyl group, it can be used in combination without any particular limitation, but the blending ratio of the curing accelerator (d1) having a cation silicate anion moiety is 50% by weight with respect to the total curing accelerator (D). The above is preferable. Examples of curing accelerators that can be used in combination include adducts of phosphine compounds and quinone compounds; diazabicycloalkenes such as 1,8-diazabicyclo (5,4,0) undecene-7 and derivatives thereof; tributylamine, benzyl Amine compounds such as dimethylamine; imidazole compounds such as 2-methylimidazole; organic phosphines such as triphenylphosphine and methyldiphenylphosphine; tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrakis (benzoyloxy) borate, tetra Examples thereof include tetra-substituted phosphonium / tetra-substituted borates such as phenylphosphonium / tetrakis (naphthoyloxy) borate, and these may be used alone or in combination of two or more.

  Since the oxidized polyethylene wax (e1) used in the present invention generally has a polar group composed of carboxylic acid and the like and a nonpolar group composed of a long carbon chain, the polar group is on the resin cured product side during molding. Alignment, and conversely, the nonpolar group functions as a release agent by orienting to the mold side.

  The dropping point of the oxidized polyethylene wax (e1) is preferably 100 ° C. or higher and 140 ° C. or lower, more preferably 110 ° C. or higher and 130 ° C. or lower. The dropping point can be measured by a method based on ASTM D127. Specifically, using a metal nipple, it is measured as the temperature at which molten wax first drops from the metal nipple. In the following examples, it can be measured by the same method. When the dropping point is within the above range, the oxidized polyethylene wax (e1) is excellent in thermal stability, and the oxidized polyethylene wax (e1) is hardly seized at the time of molding. Therefore, it is excellent in the mold release property of the hardened | cured material from a metal mold | die, and is excellent also in continuous moldability. Furthermore, when it is within the above range, the oxidized polyethylene wax (e1) is sufficiently melted when the epoxy resin composition is cured. Thereby, the oxidized polyethylene wax (e1) is dispersed substantially uniformly in the cured product. Therefore, segregation of the oxidized polyethylene wax (e1) on the surface of the cured product is suppressed, and deterioration of the mold stain and the appearance of the cured product can be reduced.

  The acid value of the oxidized polyethylene wax (e1) is preferably 10 mgKOH / g or more and 50 mgKOH / g or less, more preferably 15 mgKOH / g or more and 40 mgKOH / g or less. The acid value affects the compatibility between the cured resin and the acid value polyethylene wax (e1). The acid value affects the compatibility in the cured product. The acid value can be measured by a method based on JIS K 3504. Specifically, it is measured as the number of milligrams of potassium hydroxide required to neutralize free fatty acids contained in 1 g of waxes. In the following examples, it can be measured by the same method. When the acid value is within the above range, the oxidized polyethylene wax (e1) is in a compatible state with the epoxy resin matrix in the cured product. As a result, the oxidized polyethylene wax (e1) and the epoxy resin matrix do not cause phase separation. Therefore, segregation of the oxidized polyethylene wax (e1) on the surface of the cured product is suppressed, and deterioration of the mold stain and the appearance of the cured product can be reduced. Furthermore, since the oxidized polyethylene wax (e1) is present on the surface of the cured product, the releasability of the cured product from the mold is excellent. On the other hand, if the compatibility between the oxidized polyethylene wax (e1) and the epoxy resin matrix is too high, the oxidized polyethylene wax (e1) cannot ooze out on the surface of the cured product, and sufficient releasability cannot be ensured. There is a case.

  The number average molecular weight of the oxidized polyethylene wax (e1) is preferably 500 or more and 5000 or less, more preferably 1000 or more and 4000 or less. The number average molecular weight can be calculated by polystyrene conversion using a GPC apparatus such as HLC-8120 manufactured by Tosoh Corporation. In the following examples, it can be measured by the same method. When the number average molecular weight is within the above range, the oxidized polyethylene wax (e1) and the epoxy resin matrix are in a preferable affinity state. Therefore, the cured product is excellent in releasability from the mold. On the other hand, if the affinity between the oxidized polyethylene wax (e1) and the epoxy resin matrix is high, sufficient releasability may not be obtained. On the other hand, if the affinity is low, phase separation may occur, and the mold may become dirty or the appearance of the cured resin may be deteriorated.

The density of the oxidized polyethylene wax (e1) is preferably 0.94 g / cm ³ or more and 1.03 g / cm ³ or less, more preferably 0.97 g / cm ³ or more and 0.99 g / cm ³ or less. The density can be calculated by density measurement at 20 ° C. by a floating method based on ASTM D1505. In the following examples, it can be measured by the same method. When the density is within the above range, the oxidized polyethylene wax (e1) is excellent in thermal stability, and the oxidized polyethylene wax (e1) is hardly seized at the time of molding. Therefore, it is excellent in the mold release property of the cured product from the mold and also in the continuous moldability. Furthermore, when the epoxy resin composition is cured within the above range, the oxidized polyethylene wax (e1) is sufficiently melted. Thereby, the oxidized polyethylene wax (e1) is dispersed substantially uniformly in the cured product. Therefore, segregation of the oxidized polyethylene wax (e1) on the surface of the cured product is suppressed, and deterioration of the mold stain and the appearance of the cured product can be reduced.

  The average particle diameter of the oxidized polyethylene wax (e1) is preferably 20 μm or more and 70 μm or less, more preferably 30 μm or more and 60 μm or less. The average particle diameter can be measured by using a laser diffraction particle size distribution measuring device such as SALD-7000 manufactured by Shimadzu Corporation as a solvent and water, and a weight-based 50% particle diameter as an average particle diameter. it can. In the following examples, it can be measured by the same method. When the average particle size is within the above range, the oxidized polyethylene wax (e1) is in a compatible state with the epoxy resin matrix in the cured product. Thereby, the oxidized polyethylene wax (e1) is present on the surface of the cured product, and the release property of the cured product from the mold is excellent. On the other hand, if the compatibility with the epoxy resin matrix is too high, the cured product surface cannot be oozed out and sufficient releasability cannot be ensured. Further, since the oxidized polyethylene wax (e1) and the epoxy resin matrix are in a preferable compatible state, segregation of the oxidized polyethylene wax (e1) on the surface of the cured product is suppressed, and mold contamination and the appearance of the cured product are deteriorated. Can be reduced. Furthermore, when it is in the above range, the oxidized polyethylene wax (e1) is sufficiently melted when the epoxy resin composition is cured. Therefore, the epoxy resin composition is excellent in fluidity.

  The content ratio of particles having a particle size of 106 μm or more in the total oxidized polyethylene wax (e1) is preferably 0.1% by weight or less. This content ratio can be measured using a standard sieve having an opening of 106 μm according to JIS Z8801. In the following examples, it can be measured by the same method. If it is said content ratio, an oxidation polyethylene wax (e1) will disperse | distribute substantially uniformly and it can suppress the deterioration of the external appearance of a mold | die stain | pollution | contamination and resin cured material. In addition, when the epoxy resin composition is cured, the oxidized polyethylene wax is sufficiently melted, and thus has excellent fluidity.

  The content of the oxidized polyethylene wax (e1) is 0.01% by weight or more and 1% by weight or less in the epoxy resin composition, preferably 0.03% by weight or more and 0.5% by weight or less. It is excellent in the mold release property of the hardened | cured material from a metal mold | die within the said range. Furthermore, since the adhesiveness with the lead frame member is excellent, peeling between the lead frame member and the cured product can be suppressed during the soldering process. In addition, it is possible to suppress deterioration of the mold and the appearance of the cured product during molding.

The oxidized polyethylene wax (e1) used in the present invention is commercially available, and can be used after adjusting the particle size.
Examples of the oxidized polyethylene wax (e1) used in the present invention include a polyethylene wax oxide (e11) produced by a low pressure polymerization method, a polyethylene wax oxide (e12) produced by a high pressure polymerization method, and a high density polyethylene polymer. The oxide (e13) is preferred.
Other release agents may be used in combination as long as the effects of using the oxidized polyethylene wax (e1) used in the present invention are not impaired. Examples of release agents that can be used in combination include natural waxes such as carnauba wax, and metal salts of higher fatty acids such as zinc stearate.

  The present invention relates to a curing accelerator (d1) having a cation part capable of promoting the curing reaction of an epoxy resin and a silicate anion part suppressing the catalytic activity of the cation part promoting the curing reaction, and a polyethylene oxide wax (e1). The synergistic effect is expressed by using together the mold release agent (E) containing. By using these two types in combination, even when the amount of the inorganic filler is increased, an ideal release behavior is exhibited without impairing the dispersibility of the release agent in the cured product.

  The epoxy resin composition of the present invention comprises (A) an epoxy resin, (B) a phenol resin curing agent, (C) an inorganic filler, and (D) a curing accelerator (d1) having a cation part and a silicate anion part. And a curing accelerator containing (E) a release agent containing polyethylene oxide wax (e1), but if necessary, cups of aminosilane, epoxysilane, mercaptosilane, alkylsilane, ureidosilane, acrylicsilane, etc. Ring agents; Hydrotalcites and ion trapping agents such as hydrous oxides of elements selected from magnesium, aluminum, bismuth, titanium and zirconium; Low stress additives such as silicone oil and rubber; thiazolines, diazoles, triazoles, triazines, Adhesion imparting agents such as pyrimidine; brominated epoxy resin and anti-trioxide Emissions, aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, be suitably blended additives such as flame retardants such as phosphazene no problem.

  In addition, the epoxy resin composition of the present invention is prepared by mixing the raw materials sufficiently uniformly using a mixer or the like, and then melt-kneaded with a hot roll or a kneader, pulverized after cooling, etc. as necessary. What adjusted the dispersion degree etc. suitably can be used.

FIG. 1 is a view showing a cross-sectional structure of an example of a semiconductor device using the epoxy resin composition according to the present invention. The semiconductor element 1 is fixed on the die pad 3 via the die bond material cured body 2. The electrode pad of the semiconductor element 1 and the lead frame 5 are connected by a gold wire 4. The semiconductor element 1 is sealed with a cured body 6 of a sealing resin composition.
The epoxy resin composition of the present invention is used to encapsulate various electronic components such as semiconductor elements, and to manufacture semiconductor devices by conventional molding methods such as transfer molding, compression molding, and injection molding. do it.

Examples of the present invention are shown below, but the present invention is not limited thereto. The blending ratio is parts by weight.
In addition, it shows below about the content of the hardening accelerator and mold release agent which were used by the Example and the comparative example.

Curing accelerator 1: Compound represented by the following chemical formula (2)

Curing accelerator 2: Compound represented by the following chemical formula (3)

Curing accelerator 3: Compound represented by the following chemical formula (4)

Curing accelerator 4: Compound represented by the following chemical formula (5)

Curing accelerator 5: Compound represented by the following chemical formula (6)

Curing accelerator 6: Compound represented by the following chemical formula (7)

Curing accelerator 7: Compound represented by the following chemical formula (8)

Release agent 1: Oxidized polyethylene wax 1 (drop point 120 ° C., acid value 20 mgKOH / g, number average molecular weight 2000, density 0.98 g / cm ³ , average particle size 45 μm, particle size 106 μm or more 0.0% by weight) Oxide of high density polyethylene polymer)

Release agent 2: Oxidized polyethylene wax 2 (dropping point 110 ° C., acid value 12 mg KOH / g, number average molecular weight 1200, density 0.97 g / cm ³ , average particle size 50 μm, particle size 106 μm or more 0.0% by weight) Oxide of high density polyethylene polymer)

Release agent 3: Oxidized polyethylene wax 3 (dropping point 110 ° C., acid value 20 mg KOH / g, number average molecular weight 1100, density 0.95 g / cm ³ , average particle diameter 45 μm, particle diameter 106 μm or more 0.0% by weight) Polyethylene wax oxide produced by low pressure polymerization method)

Release agent 4: Polyethylene wax (drop point 135 ° C., acid value 0 mg KOH / g, number average molecular weight 5500, density 0.93 g / cm ³ , average particle size 45 μm, particle size 106 μm or more, 0.0% by weight, low pressure Polyethylene wax produced by polymerization)

  Mold release agent 5: Carnauba wax (Nikko Fine Products Co., Ltd., trade name Nikko Carnauba)

Here, as an example, a method for synthesizing the curing accelerator 1 will be described, but the present invention is not limited thereto.
In a flask containing 1800 g of methanol, 249.5 g of phenyltrimethoxysilane and 384.0 g of 2,3-dihydroxynaphthalene were added and dissolved, and then 231.5 g of 28% sodium methoxide-methanol solution was added dropwise with stirring at room temperature. Furthermore, when a solution prepared by dissolving 503.0 g of tetraphenylphosphonium bromide prepared in advance in 600 g of methanol was added dropwise with stirring at room temperature, crystals were deposited. The precipitated crystals were filtered, washed with water, and vacuum-dried to obtain a pinky white crystal curing accelerator 1.

Example 1
Epoxy resin 1: phenol aralkyl type epoxy resin having a biphenylene skeleton represented by the following formula (9) (Nippon Kayaku Co., Ltd., trade name: NC3000P, softening point: 58 ° C., epoxy equivalent: 273) 67 parts by weight

Phenol resin 1: phenol aralkyl resin having a biphenylene skeleton represented by the following formula (10) (Maywa Kasei Co., Ltd., trade name MEH-7851SS, softening point 107 ° C., hydroxyl group equivalent 204) 40 parts by weight

Fused spherical silica 1: (average particle size 20 μm, specific surface area 3.6 m ² / g)
780 parts by weight Fused spherical silica 2: (average particle size 0.5 μm, specific surface area 5.9 m ² / g)
100 parts by weight Curing accelerator 1 5 parts by weight Release agent 1 2 parts by weight Coupling agent: γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403) 3 parts by weight Carbon black: (Mitsubishi Chemical Co., Ltd., trade name MA-600) 3 parts by weight are mixed with a mixer, melt kneaded at 95 ° C. for 8 minutes using a heat roll, cooled and pulverized to obtain an epoxy resin composition. It was. The obtained epoxy resin composition was evaluated by the following methods. The results are shown in Table 1.

Evaluation method: Spiral flow: Using a low-pressure transfer molding machine (KTS-15, manufactured by Kotaki Seiki Co., Ltd.), a mold for spiral flow measurement according to EMMI-1-66, a mold temperature of 175 ° C. and an injection pressure of 6. The epoxy resin composition was injected under the conditions of 9 MPa and curing time of 120 seconds, and the flow length was measured.

  Metal wire flow rate: 160 pin low profile quadrature using a low pressure transfer automatic molding machine (Daiichi Seiko, GP-ELF) under conditions of a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 70 seconds. Flat package (160pLQFP; pre-plating frame, gold-plated nickel / palladium alloy, package outer dimensions: 24 mm x 24 mm x 1.4 mm thickness, pad size: 8.5 mm x 8.5 mm, chip size 7.4 mm x 7. 4 mm) was obtained by sealing with an epoxy resin composition. The obtained 160pLQFP package was observed with a soft X-ray fluoroscope (PRO-TEST100, manufactured by Softex Corp.), and the flow rate of the gold wire was expressed as a ratio of (flow rate) / (gold wire length). The criterion was ○ for less than 5% and x for 5% or more.

  Curability (curing torque ratio): Using a curast meter (manufactured by Orientec Co., Ltd., JSR curast meter IVPS type), under the conditions of a die diameter of 35 mm, an amplitude angle of 1 °, and a mold temperature of 175 ° C. The curing behavior of the resin composition charged in the apparatus is measured by a change in torque. From the torque values 60 seconds and 300 seconds after the start of measurement, the curing torque ratio: (torque after 60 seconds) / (torque after 300 seconds) was calculated. The curing torque ratio in the curast meter is a parameter representing curability, and the larger the curing torque ratio, the better the curability. Judgment criteria set 0.7 or more as ◯ and less than 0.7 as x.

Continuous formability: 80-pin quad flat machine using a low-pressure automatic transfer molding machine (Daiichi Seiko, GP-ELF) under conditions of a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 70 seconds. Package (80pQFP; Cu lead frame, package outer dimensions: 14mm x 20mm x 2mm thickness, pad size: 6.5mm x 6.5mm, thickness 250μm, chip size 6.0mm x 6.0mm, thickness 350μm) The epoxy resin composition was continuously molded up to 500 shots. The judgment criteria were “good” for those that could be continuously molded up to 500 shots without occurrence of unfilling, and “x” for others.

  Package Appearance and Mold Dirt: In the evaluation of the continuous moldability, the package surface and mold surface after 500 shot molding were visually evaluated for dirt. The package appearance judgment and the mold contamination standard are indicated by “x” when dirty and by “◯” when not dirty up to 500 shots. In the above-mentioned continuous formability, those that could not be molded without occurrence of unfilling up to 500 shots were judged based on the package appearance and mold contamination status when the continuous molding was abandoned.

  Solder resistance: 80-pin quad flat package using a low-pressure transfer molding machine (Daiichi Seiko, GP-ELF) under conditions of a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 90 seconds. (80pQFP; 80-pin pre-plating frame, NiPd alloy plated with Au, package outer dimensions: 14 mm x 20 mm, thickness 2 mm, pad size: 8 mm x 8 mm, thickness 250 μm, chip size: 7 mm x 7 mm, thickness 350 μm) was obtained by sealing with an epoxy resin composition. The obtained package was heat-treated at 175 ° C. for 8 hours as an afterbake. Then, after performing the humidification process for 120 hours at 85 degreeC and 85% of relative humidity, IR reflow process of 260 degreeC was performed. Peeling and cracks inside the package were confirmed with an ultrasonic flaw detector. The number of defective packages among the 10 packages is shown.

Examples 2 to 12, Comparative Examples 1 to 6
According to the composition of Table 1, Table 2, and Table 3, an epoxy resin composition was obtained in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 1, Table 2, and Table 3.
The raw materials used other than Example 1 are shown below.
Epoxy resin 2: Biphenyl type epoxy resin represented by the following formula (11) (manufactured by Japan Epoxy Resin Co., Ltd., trade name YX-4000, epoxy equivalent 190, melting point 105 ° C.)

Phenol resin 2: Phenol aralkyl resin represented by the following formula (12) (Mitsui Chemicals, trade name: XLC-LL, hydroxyl group equivalent: 165, softening point: 79 ° C.)

  Although the curing accelerator (d1) having a cation part and a silicate anion part is used, in Comparative Example 1 in which the oxidized polyethylene wax (e1) is not used, the releasability is insufficient. Resin trays and the like were generated, and continuous molding was not possible up to 500 shots. Moreover, the release resistance when the package was removed from the mold was an incentive, resulting in poor solder resistance. Moreover, although the hardening accelerator (d1) is used, in the comparative examples 2 and 3 using polyethylene wax and carnauba wax in place of the oxidized polyethylene wax (e1), releasability is insufficient. Therefore, continuous molding could not be performed up to 500 shots. Also in this case, the release resistance was an incentive, resulting in poor solder resistance. Further, although the oxidized polyethylene wax (e1) is used, instead of the curing accelerator (d1) having a cation part and a silicate anion part, respectively, a compound represented by the chemical formula (6) and a chemical formula (7) In Comparative Examples 4 and 5 using the represented compounds, although the mold release property is good, continuous molding is possible, but the package exudation and mold contamination occur due to non-uniform leaching of the mold release agent. It was. Further, in Comparative Examples 4 and 5, the fluidity (spiral flow) was lowered and the gold wire flow was inferior. In Comparative Example 6 in which the compound represented by the chemical formula (8) was used instead of the curing accelerator (d1) and carnauba wax was used instead of the oxidized polyethylene wax (e1), fluidity, gold wire flow, and curing Performance, continuous formability, package appearance, mold contamination, and solder resistance were all inferior.

  On the other hand, Examples 1 to 12 are resin compositions containing a curing accelerator (d1) having a cation portion and a silicate anion portion and an oxidized polyethylene wax (e1), and the component (d1) and the component (e1) In any case, it is included in all of fluidity, wire flow, curability, continuous formability, package appearance, mold contamination, and solder resistance. Results were obtained. From the above, by providing the above components (d1) and (e1), it has good fluidity, curability, releasability and continuous formability at the time of sealing molding of semiconductor elements and the like, and is lead-free. It can be seen that good solder resistance without peeling or cracking can be achieved even by high-temperature soldering corresponding to solder.

  According to the present invention, it has good fluidity, curability, releasability, and continuous formability at the time of sealing molding, and good resistance to peeling and cracking even by high-temperature solder processing corresponding to lead-free solder. Since an epoxy resin composition for semiconductor encapsulation having solderability can be obtained, it can be suitably used for the production of industrial resin-encapsulated semiconductor devices, in particular, resin-encapsulated semiconductor devices for surface mounting.

It is the figure which showed the cross-section about an example of the semiconductor device using the epoxy resin composition which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Die-bonding material hardening body 3 Die pad 4 Gold wire 5 Lead frame 6 Hardening body of resin composition for sealing

Claims (10)

In the epoxy resin composition containing (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) an inorganic filler, (D) a curing accelerator, and (E) a release agent, the curing accelerator (D ) Contains a curing accelerator (d1) having a cation part and a silicate anion part, and the release agent (E) contains an oxidized polyethylene wax (e1). The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the cation part of the curing accelerator (d1) having the cation part and the silicate anion part contains a phosphorus cation. The epoxy resin composition for semiconductor encapsulation according to claim 1 or 2, wherein the curing accelerator (d1) having the cation part and the silicate anion part is a compound represented by the following general formula (1).

(In the above general formula (1), R ¹ , R ² , R ³ and R ⁴ each represents an organic group or an aliphatic group having an aromatic ring or a heterocyclic ring, and they may be the same or different from each other. X ¹ is an organic group bonded to the groups Y ¹ and Y ^2. X ² is an organic group bonded to the groups Y ³ and Y ^4. Y ¹ and Y ² are proton donating groups. The substituent is a group formed by releasing a proton, and the groups Y ¹ and Y ² in the same molecule are bonded to a silicon atom to form a chelate structure, and Y ³ and Y ⁴ are proton-donating substitutions. The group is a group formed by releasing a proton, and the groups Y ³ and Y ⁴ in the same molecule are bonded to a silicon atom to form a chelate structure, and X ¹ and X ² are the same as each other. Y ¹ , Y ² , Y ³ , and Y ⁴ may be the same or different from each other. Z ¹ represents an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group.) The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 3, wherein the dropping point of the oxidized polyethylene wax (e1) is 100 ° C or higher and 140 ° C or lower. The average particle size of the oxidized polyethylene wax (e1) is 20 µm or more and 70 µm or less, and the content ratio of particles having a particle size of 106 µm or more in the total oxidized polyethylene wax (e1) is 0.1 wt% or less. The epoxy resin composition for semiconductor sealing in any one of Claim thru | or 4. The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 5, wherein the acid value of the oxidized polyethylene wax (e1) is 10 mgKOH / g or more and 50 mgKOH / g or less. The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 6, wherein the oxidized polyethylene wax (e1) has a number average molecular weight of 500 or more and 5000 or less. The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 7, wherein the density of the oxidized polyethylene wax (e1) is 0.94 g / cm ³ or more and 1.03 g / cm ³ or less. The oxidized polyethylene wax (e1) is a polyethylene wax oxide (e11) produced by a low pressure polymerization method, a polyethylene wax oxide (e12) produced by a high pressure polymerization method, and a high density polyethylene polymer oxide (e13). The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 8, wherein the epoxy resin composition is for semiconductor encapsulation. A semiconductor device comprising a semiconductor element sealed using the epoxy resin composition for semiconductor sealing according to any one of claims 1 to 9.

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