TW201341421A - Epoxy resin hardening accelerator - Google Patents

Abstract

A hardening accelerator is provided. In an epoxy resin composition for sealing semiconductors, the hardening accelerator can lower melting viscosity of the composition to increase liquid fluidity. On the other hand, the hardening accelerator can improve demolding property by heightening initial hardness during hardening. An epoxy resin hardening accelerator is formed by including a quaternary phosphonium (A) represented by formula (1) and a phenol resin (B) providing a phenoxide ion served as an anion with respect to the quaternary phosphonium. [In the formula, R1 to R5 respectively represents a hydrogen atom, a linear chain or branched alkyl group having a carbon number from 1 to 4, or an alkoxy group having a carbon number from 1 to 4.]

Description

Epoxy resin hardening accelerator

The present invention relates to an epoxy resin hardening accelerator. More specifically, the present invention relates to an epoxy resin hardening accelerator containing a quaternary phosphonium salt suitable for the production of an epoxy resin-based sealing material for electronic parts such as semiconductors.

Since the prior art, the novolac type epoxy resin or the biphenyl type epoxy resin has been widely used for various other electronic parts such as semiconductor wafers in terms of hardening characteristics and the like. Further, triphenylphosphine (hereinafter abbreviated as TPP (Triphenylphosphine)) is used as a curing accelerator for these epoxy resins.

The curing of the epoxy resin using TPP as the curing accelerator is low in initial hardness at the time of curing, and it is difficult to release the mold from the mold during the production of the semiconductor wafer, so that there is a problem that the rapid flow of the semiconductor wafer production line becomes difficult. As a method for improving the problem, tetraphenylborate of tetraphenylphosphonium (hereinafter abbreviated as TTP-K (Tetraphenylphosphonium tetraphenylborate)) (refer to Patent Document 1), alkyl quaternary phosphonium and polyphenol of TPP have been proposed. Salt (see Patent Document 2), a salt of an alkyl quaternized hydrazine of TPP and a phenol resin (see Patent Document 3 and Patent Document 4). However, if these hardening accelerators are used, the initial hardness of the epoxy resin during hardening Though it is higher than when TPP is used, it is easy to release the mold, but when it is used for a sealing material in which an inorganic filler such as cerium oxide is added in a high concentration in order to improve heat resistance (thus, the ratio of the resin component is lowered), the hardness Still not enough, the improvement of mold release is not sufficient.

Moreover, TPP-K has low activity due to the catalyst, so it is only formulated to epoxy resin and In the hardener, the hardening is not sufficiently performed, and it is necessary to previously prepare the phenol resin and heat it to convert the tetraphenylborate into a phenol resin salt. At this time, there is a problem that a toxic benzene is slightly generated. Further, the polyalkylene salt of the alkyl quaternized hydrazine of TPP has a melting point of 150 ° C or more, and it is difficult to mix with an epoxy resin, which causes a poor mixing and causes uneven density, which causes a hardening failure. Further, in the sealing material composition in which the inorganic filler is blended at a high concentration, when a phenol resin salt of an alkyl quaternized hydrazine of TPP is used as a hardening accelerator, a mixture of an epoxy resin, a hardener, and a hardening accelerator is used. Since the viscosity of the preparation liquid heated and melted becomes high, it is a cause of the so-called liquid fluidity defect, and the liquid fluidity defect means the wiring of the semiconductor wafer at the time of mold filling, or the viscosity before the preparation is spread over every corner. Rise to form an unfilled portion.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 48-800

[Patent Document 2] Japanese Patent Laid-Open No. 55-157594

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-256643

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2005-162944

In view of the above, an object of the present invention is to provide a curing accelerator for curing an epoxy resin, which can improve the viscosity of a preparation liquid obtained by heating and melting a mixture containing an epoxy resin, a curing agent, and a curing accelerator. Liquid fluidity, on the other hand, can improve the initial hardness at the time of hardening to improve the mold release property.

In order to solve the above problems, the inventors of the present invention have found that a curing accelerator capable of solving the above problems has been found, and the present invention has been completed. That is, the present invention is an epoxy resin hardening accelerator comprising a quaternary phosphonium (A) represented by the general formula (1) and a phenoxy ion provided as an anion corresponding to the above-described fourth-order ruthenium (A) ( Phenoxide ion) formed by the phenol resin (B).

In the formula, R1 to R5 each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.

According to the present invention, it is possible to obtain an epoxy resin hardening accelerator having the following characteristics: the formulation liquid obtained by heating and melting the epoxy resin, the curing agent, and the curing accelerator is suppressed to have a low viscosity. It brings rapid hardening and imparts high initial hardness to the epoxy resin during hardening. Hardening with the above epoxy resin Since the semiconductor sealing material composition of the agent is excellent in liquid fluidity when it is filled in a molding die of a semiconductor wafer, excessive force during filling can be prevented from acting on the wiring of the semiconductor, and the preparation can be easily spread over various corners, and The hardened semiconductor wafer is quickly released from the mold, and since the initial hardness is high, the inorganic filler can be blended at a high concentration in order to improve heat resistance, and therefore it is particularly suitable for use in a semiconductor sealing material.

Hereinafter, embodiments of the present invention will be described in detail.

In the quaternary phosphonium (A) represented by the formula (1), R1 to R5 each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a carbon number of 1 to 4; Alkoxy group. R1 to R5 are preferably hydrogen, methyl or methoxy.

The quaternary ruthenium (A) represented by the above formula (1) is characterized by having a specific quaternary phosphonium cation structure in which an ethyl group is bonded to a phosphorus element on the cation side, and the specific structure is imparted as a promoter. High hardening performance. As the quaternary phosphonium (A) represented by the formula (1), triphenylethylphosphonium, tris(m-methylphenyl)ethylanthracene or tris(o-methoxyphenyl)ethyl group is preferred.鏻, particularly preferably triphenylethyl hydrazine (in the formula (1), R1 to R5 are each a hydrogen atom).

The epoxy resin hardening accelerator of the present invention comprises a phenol resin (B) which provides a phenoxy ion as a quaternary ruthenium (A) pair represented by the general formula (1) The anion should be.

Examples of the phenol resin (B) include a phenol novolak resin, a cresol novolak resin, and a resin represented by the formula (2).

Wherein R6 is a hydrogen atom or a methyl group; R7 is a linear or branched alkyl group having a carbon number of 1 to 4, an alkoxy group having a carbon number of 1 to 4, a hydroxyl group, or a halogen atom; and Z is selected from the group consisting of In the structure of the following group, m and n are each an integer of 0 to 20, and represent an integer of m+n=0 to 20]

Among the resins represented by the formula (2), a resin wherein R6 is a hydrogen atom, R7 is a methoxy group or an ethoxy group, and Z is a -CH2- group is preferred.

By replacing the phenolic hydroxyl group in the phenol resin with an alkoxy group (methoxy or ethoxy group), the viscosity of the accelerator itself is lowered, and the mixing time with the epoxy resin or the like is shortened, and the epoxy resin can be blended. The reaction with the hardener is suppressed to be low, and as a result, the initial fluidity at the time of molding is improved.

Therefore, as a method for producing the curing accelerator of the present invention, for example, the following methods [I] to [III] can be used, and it is preferable that the halogen ion and the alkali metal are each 5 ppm or less. Is the method of [I] or [II].

[I] in the presence or absence of a solvent (for example, ethanol: used in an amount of 10 wt% (weight%) to 1,000 wt% based on the weight of the tertiary phosphine), preferably 40 ° C to 200 ° C, preferably 80 The reaction temperature of °C to 170 °C reacts a tertiary phosphine which is a raw material of the fourth-grade cerium (A) with an equivalent amount or more (preferably 1.1 equivalents to 5.0 equivalents) of diethyl carbonate to form a quaternary phosphonium salt, and further The above phenol resin (B) (equivalent to 1.0 equivalent to 1.5 equivalent based on the quaternary phosphonium) was added, and the mixture was stirred at 10 ° C to 150 ° C for 1 hour to carry out salt exchange. The excess diethyl carbonate is separated from the solvent at 80 ° C to 150 ° C under normal pressure or reduced pressure to obtain a target hardening accelerator. In addition, the unit MPa of the following decompression means the gage pressure.

[II] mixing a tertiary phosphine as a raw material of (A) with diethyl carbonate and the above phenol resin (B) in the same amount as in the method of [I], in the presence or absence of a solvent, After the reaction is carried out at a reaction temperature of 40 ° C to 200 ° C, preferably 80 ° C to 170 ° C, the excess diethyl carbonate is separated from the solvent at 80 ° C to 150 ° C under normal pressure or reduced pressure to obtain a target. Hardening accelerator.

[III] In the presence of a solvent (for example, toluene: used in an amount of 10% by weight to 1,000% by weight based on the weight of the tertiary phosphine), the reaction temperature is from 10 ° C to 100 ° C, preferably from 40 ° C to 100 ° C. The tertiary phosphine as the raw material of (A) is reacted with 1.0 equivalent to 1.5 equivalents of ethyl halide (Ethyl Halide) to form a quaternary phosphonium salt. For the quaternary phosphonium salt, 1 equivalent of sodium hydroxide and 1.0 equivalent to 1.5 equivalents of phenol resin are used (B) Perform salt exchange, remove 50%~400% of water based on the weight of the mixture, and remove the organic layer of the salt at 10 ° C ~ 100 ° C, 80 ° C ~ 150 ° C under normal pressure or reduced pressure The solvent is separated to obtain a target hardening accelerator.

For example, epoxy resin (component A) and phenol resin (component B) are hardened. In the case of 100 parts by weight of the phenol resin (component B) (hereinafter referred to as "parts"), the amount of the curing accelerator of the present invention is preferably in the range of 5 parts to 20 parts, more preferably 6 parts. ~15 servings. In other words, if the amount is less than 5 parts, the curing reaction between the target epoxy resin (component A) and the phenol resin (component B) is difficult to proceed, so that it is difficult to obtain sufficient curability; if it exceeds 20 parts, It can be seen that the hardening reaction is too fast to impair the formability.

In addition, it is also known that it is not within the scope of the characteristics of the present invention. Various hardening accelerators are used in combination with the hardening accelerator of the present invention. Examples of the various hardening accelerators known in the prior art include triarylphosphines and tetraphenylphosphonium. Imidazoles such as tetraphenylborate and 2-methylimidazole, 1,8-diazabicyclo(5,4,0)undecene-7 and the like. These hardening accelerators may be used alone or in combination of two or more.

The epoxy resin composition using the hardening accelerator of the present invention is also optionally An inorganic filler such as molten cerium oxide or aluminum oxide, a coupling agent such as epoxysilane, vinyl decane or titanate, stearic acid and its metal salt, palm wax, etc. An internal mold release agent which is easy to release the mold, a pigment such as carbon black, a flame retardant such as tetrabromobisphenol A, ammonium polyphosphate or antimony trioxide.

Manufacture of epoxy resin composition using the hardening accelerator of the present invention In the kneading device such as a kneader or a three-roller, the epoxy resin (component A) and the curing agent (component B) are heated at a temperature of 80 ° C to 120 ° C, preferably 90 ° C to 110 ° C. The hardening accelerator of the present invention and other additives are melt-mixed and kneaded. The obtained mixture is cooled, solidified, and pulverized, and if necessary, can be produced by tableting into a tablet.

[Examples]

The invention is further illustrated by the following examples, but is not intended to limit the invention thereto. In the examples, "parts" means parts by mass.

Example 1 [hardening accelerator a1]

Phenol resin salt of triphenylethyl hydrazine (softening point is 108 ° C)

24 parts of diethyl carbonate, 36 parts of ethanol, and 60 parts of triphenylphosphine were added to a stirred autoclave, and reacted at a reaction temperature of 160 ° C for 80 hours to obtain a triphenylethyl fluorene. Ethyl carbonate in ethanol.

The above-obtained triphenylethylguanidine was slowly added to a reaction vessel containing 80 parts of a phenol novolak resin (manufactured by Megumi Kasei Co., Ltd., trade name: MEHC-7800S) which was heated and melted at 150 ° C. 24 parts of an ethanol solution of ethyl carbonate was used to remove the generated carbon dioxide, and the pressure was reduced to remove the remaining ethanol. The obtained molten salt was taken out, cooled to room temperature, and then pulverized by a table pulverizer and passed through a mesh of 100 meshes to prepare a powdery hardening accelerator a1.

Example 2 [hardening accelerator a2]

Phenolic novolac resin salt of triphenylethyl hydrazine (softening point is 100 ° C)

A hardening accelerator a2 was obtained in the same manner as in the above Example 1, except that MEFC-7800S was used instead of the phenol resin, which was a phenol novolak resin (manufactured by Megumi Kasei Co., Ltd., trade name: MF-4).

Example 3 [hardening accelerator a3]

Phenolic novolac resin salt of triphenylethyl hydrazine (softening point is 103 ° C)

A hardening accelerator a3 was obtained in the same manner as in the above Example 1, except that MEFC-7800S was used instead of the phenol resin, which was a phenol novolak resin (manufactured by Megumi Kasei Co., Ltd., trade name: MF-1M).

Example 4 [hardening accelerator a4]

Phenolic novolac resin salt of triphenylethyl hydrazine (softening point is 105 ° C)

A hardening accelerator a4 was obtained in the same manner as in the above Example 1, except that phenol novolak resin (manufactured by Megumi Kasei Co., Ltd., trade name: MF-3M) was used instead of the phenol resin MEHC-7800S.

Example 5 [hardening accelerator a5]

Phenolic novolac modified resin salt of triphenylethyl hydrazine (softening point is 98 ° C)

A hardening accelerator a5 was obtained in the same manner as in the above Example 1, except that MEFC-7800S in which a phenol novolak resin (a resin in which a phenol group of MF-4 was 25% ethylated) was used instead of the phenol resin.

Example 6 [hardening accelerator a6]

Phenolic novolac modified resin salt of triphenylethyl hydrazine (softening point is 95 ° C)

In addition to the use of phenol novolac resin (the phenolic group of MF-4 is 25% methylated) A hardening accelerator a6 was obtained in the same manner as in the above Example 1 except that MECC-7800S was used instead of the phenol resin.

Example 7 [hardening accelerator a7]

Phenolic novolac modified resin salt of triphenylethyl hydrazine (softening point is 100 ° C)

A hardening accelerator a7 was obtained in the same manner as in the above Example 1, except that MEFC-7800S in which a phenol novolak resin (a resin in which a phenol group of MF-1M was 25% ethylated) was used instead of the phenol resin.

Example 8 [hardening accelerator a8]

Phenolic novolac modified resin salt of triphenylethyl hydrazine (softening point is 100 ° C)

A hardening accelerator a8 was obtained in the same manner as in the above Example 1, except that MEFC-7800S in which a phenol novolak resin (a resin in which a phenol group of MF-1M was methylated by 25%) was used instead of the phenol resin.

Example 9 [hardening accelerator a9]

Phenolic novolac modified resin salt of triphenylethyl hydrazine (softening point is 105 ° C)

A hardening accelerator a9 was obtained in the same manner as in the above Example 1, except that MEFC-7800S in which a phenol novolak resin (a resin in which a phenol group of MF-3M was ethylated by 25%) was used instead of the phenol resin.

Example 10 [hardening accelerator a10]

Phenolic novolac modified resin salt of triphenylethyl hydrazine (softening point is 105 ° C)

A hardening accelerator a10 was obtained in the same manner as in the above Example 1, except that MEFC-7800S in which a phenol novolak resin (a resin in which a phenol group of MF-3M was methylated by 25%) was used instead of the phenol resin.

Example 11 [hardening accelerator a11]

Phenolic novolac resin salt of triphenylethyl hydrazine (softening point is 110 ° C)

20 parts of diethyl carbonate, 6 parts of ethanol, 26 parts of triphenylphosphine, and 120 parts of phenol novolak resin (manufactured by Mingwa Chemical Co., Ltd., trade name: MF-4M) were added to the high temperature and high pressure sealed reactor. After reacting for 80 hours at a reaction temperature of ° C, the pressure was reduced to remove the remaining raw material. The obtained molten salt was taken out, cooled to room temperature, and then pulverized by a table pulverizer and passed through a mesh of 100 meshes to prepare a powdery hardening accelerator a11.

Example 12 [hardening accelerator a12]

Triphenylethyl hydrazine phenol novolac modified resin salt (softening point is 108 ° C)

A hardening accelerator a12 was obtained in the same manner as in the above Example 11 except that MEFC-7800S which used a phenol novolak resin (a resin in which the phenol group of MF-4M was 25% ethylated) was used instead of the phenol resin.

Comparative Example 1 [hardening accelerator b]

TPP-K (tetraphenylphosphonium tetraphenylborate)

Comparative Example 2 [hardening accelerator c]

TPM-P (methyltriphenylphosphonium-p-xylylene phenolate resin, softening point is 110 ° C)

<Sclerosing test>

A component

[Epoxy resin]

Biphenyl type epoxy resin (epoxy equivalent 186, melting point 105 ° C)

Component B

[phenol resin]

P-xylylene phenol resin (hydroxy equivalent weight 176, softening point 80 ° C)

C component

Hardening accelerators of Examples 1 to 12, Comparative Example 1, and Comparative Example 2

With respect to the powdery hardening accelerators obtained in Examples 1 to 12 and Comparative Examples 1 to 2, the amount of addition was adjusted so that the gel time at 175 ° C was 35 seconds, and the above-mentioned addition was added. 100 parts of the benzene type epoxy resin and the adjustment amount of the above-mentioned curing agent (the total number of OH group equivalents of various phenol resins contained in the curing accelerator and the number of OH group equivalents of the curing agent, and the epoxy resin of the epoxy resin) The blending amount was adjusted in such a manner that the ratio of the number of equivalents became 1/1, and then uniformly mixed using an automatic mortar (manufactured by AS ONE). The mixture was kneaded for 5 minutes using a hot roll at 100 °C. After cooling, coarse pulverization was carried out, and then an ingot having a diameter of 15 mm was produced by a press. The ingot was used and the gel time of 175 ° C and the torque value after 90 seconds were measured by a Curelastometer (manufactured by Nikken Co., Ltd.), and the evaluation was made. The initial hardenability of the price. The component compositions of the respective examples of the obtained initial cured product and the results obtained are shown in Table 1.

According to the results of the hardening torque and Tg after 90 seconds, compared with the comparative example, The hardening accelerator of the present invention has a sharp rise in torque when it is hardened and has a high Tg of the cured product.

That is, it is understood that the hardening accelerator of the present invention has better curing promotion performance than the comparison. Examples of TPP-K, TPM-P.

[Industrial availability]

Since the hardening accelerator of the present invention can achieve rapid hardening of the epoxy resin and high hardness of the cured product, it is provided as a curing agent for providing an epoxy resin for a sealing material which is excellent in filling property in semiconductor wafer production and excellent in mold release property. The agent is useful. Further, since the epoxy hardening reaction has a high promoting effect, it can be applied to other electronic materials such as conductive materials and substrate insulating materials, as well as applications such as adhesives and paints.

Claims (7)

An epoxy resin hardening accelerator comprising a quaternary phosphonium (A) represented by the general formula (1) and a phenol resin (B) which provides a phenoxide ion as an anion corresponding to the above-described fourth-order ruthenium (A) And formed, In the formula, R1 to R5 each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. The epoxy resin hardening accelerator according to claim 1, wherein in the above formula (1), R1 to R5 are each a hydrogen atom. The epoxy resin hardening accelerator according to the first or second aspect of the invention, wherein the phenol resin (B) is a phenol novolak resin, a cresol novolak resin, or a compound represented by the formula (2) Resin, Wherein R6 is a hydrogen atom or a methyl group; R7 is a linear or branched alkyl group having a carbon number of 1 to 4, an alkoxy group having a carbon number of 1 to 4, a hydroxyl group, or a halogen atom; and Z is selected from the group consisting of In the structure of the following group, m and n are each an integer of 0 to 20, and represent an integer of m+n=0 to 20] The epoxy resin hardening accelerator according to claim 3, wherein in the above formula (2), R6 is a hydrogen atom, R7 is a methoxy group or an ethoxy group, and Z is a -CH2- group. The epoxy resin hardening accelerator according to any one of the items 1 to 4, wherein the weight of the halogen ion or the alkali metal ion based on the weight of the epoxy resin hardening accelerator is 5 ppm or less. . An epoxy resin composition comprising an epoxy resin, a hardener, and an epoxy resin hardening accelerator according to any one of claims 1 to 5. A cured product formed by hardening an epoxy resin composition as described in claim 6 of the patent application.