JP2000234048A - Semiconductor sealing epoxy resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor sealing epoxy resin composition which improves the shelf stability at ordinary temperatures without microcapsulation of curing accelerators. SOLUTION: A semiconductor sealing epoxy resin composition contains as essential components an epoxy resin, a hardener, an accelerator and an inorganic filler. Here, the epoxy resin is an o-cresol novolak epoxy resin, the hardener is a phenol novolak resin, and the curing accelerator is a compound having a skeleton of the formula. In the formula, R1-R7 are each hydrogen, methyl or hydroxyethyl.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for encapsulating a semiconductor and a semiconductor device using the epoxy resin composition for encapsulating a semiconductor.

[0002]

2. Description of the Related Art Conventionally, as a method of sealing electric / electronic parts such as diodes, transistors, integrated circuits, etc., semiconductor devices, etc., for example, a method of sealing with epoxy resin or silicon resin, glass, metal, ceramic, etc. Hermetic sealing method using
Resin encapsulation by low-pressure transfer molding using an epoxy resin, which has the merit of being able to improve reliability and is cost-effective, has become the mainstream.

In a sealing method using this epoxy resin, an o-cresol novolak type epoxy resin is used as a resin component, a phenol novolak resin as a curing agent, an organic phosphorus compound as a curing accelerator, tertiary amines,
Epoxy resin compositions containing imidazoles are commonly used.

[0004]

However, since the curing reaction of the epoxy resin composition proceeds at room temperature and the material deteriorates, the transportation and storage of the epoxy resin composition are performed at 5 ° C.
A certain degree of refrigeration is required, and the pot life after returning the epoxy resin composition to room temperature is generally about 24 to 72 hours. Therefore, there is a problem that the epoxy resin composition has many restrictions in transportation, storage and use. Therefore, in Japanese Patent Application Laid-Open No. 10-182949,
By using a curing accelerator coated with a thermoplastic resin and microencapsulated, the storage stability of the epoxy resin is enhanced, but this has caused problems such as cost.

[0005] The present invention has been made in view of the above points, without the need to microencapsulate the curing accelerator,
An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation and a semiconductor device that can enhance the storage stability at room temperature.

[0006]

The epoxy resin composition for semiconductor encapsulation according to claim 1 of the present invention comprises an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler as essential components. In the epoxy resin composition, an o-cresol novolak type epoxy resin is used as an epoxy resin, a phenol novolak resin is used as a curing agent, and a compound having a skeleton of the following formula (1) is used as a curing accelerator. Is what you do.

[0007]

Embedded image

Further, the invention of claim 2 provides a curing accelerator having a skeleton of the above formula (1) in an amount of from 1.0 to 20% based on the total amount of the resin.
% By weight.

The invention according to claim 3 is characterized in that the inorganic filler is blended in an amount of 60 to 93% by weight based on the total amount of the composition.

A semiconductor device according to a fourth aspect of the present invention is characterized in that a semiconductor is sealed with the epoxy resin composition according to any one of the first to third aspects.

[0011]

Embodiments of the present invention will be described below.

In the present invention, the epoxy resin may be o
-A cresol novolak type epoxy resin is used, and other epoxy resins that can be used other than the o-cresol novolak type epoxy resin include biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin, and bromide-containing epoxy resin. Resin, an epoxy resin having a naphthalene ring, and the like. o-
The cresol novolak type epoxy resin is preferably blended so as to account for 50 to 100% by weight of the total amount of the epoxy resin in the epoxy resin composition.

In the present invention, a phenol novolak resin is used as a curing agent. In addition to the phenol novolak resin, a compound having two or more phenolic hydroxyl groups in one molecule may be blended as a curing agent. For example, there are phenol ziloc resin, naphthol resin, phenol aralkyl resin and the like. The phenol novolak resin is preferably blended so as to account for 50 to 100% by weight of the total amount of the curing agent.

Further, as a curing accelerator (curing aid),
A compound having a skeleton represented by the above formula (1) is used. As a curing accelerator that can be used in addition to the compound represented by the formula (1), an organic phosphorus compound such as triphenylphosphine, trimetatrilephosphine, triparatolylphosphine, etc.
1,8-diazabicyclo (5,4,0) undecene-7
Examples include tertiary amines such as (DBU) and imidazoles such as 2-phenylimidazole (2PZ). The curing accelerator having the skeleton of the above formula (1) is preferably blended so as to account for 50 to 100% by weight of the total amount of the curing accelerator in the epoxy resin composition.

Further, in the present invention, as the inorganic filler, fused silica, crystalline silica, alumina, silicon nitride and the like can be used, and among these, fused silica is preferable.

The epoxy resin, the curing agent, the curing accelerator, and the inorganic filler are blended as essential components, and further, if necessary, a coupling agent, a flame retardant, a pigment, a silicone flexible agent, and the like are blended. This is uniformly mixed with a mixer, a blender, or the like, and then heated and kneaded with a kneader, a roll, or the like, whereby the epoxy resin composition for semiconductor encapsulation according to the present invention can be obtained. After kneading in this manner, the mixture may be cooled and solidified as required, and may be pulverized and used in the form of powder.

Here, the compounding amount of the curing agent to the epoxy resin is determined by the ratio (X / mol) of the number of moles of epoxy group (X) of the epoxy resin to the number of moles of phenolic hydroxyl group (Y) of the curing agent.
Y) is preferably set to be 0.7 to 1.3, and if it is out of this range, it may be disadvantageous in the curability at the time of curing or the low stress property of the cured product. The compounding amount of the curing accelerator is preferably in the range of 0.3 to 30 parts by weight based on 100 parts by weight of the total of the epoxy resin and the curing agent, but the curing accelerator having the skeleton of the above formula (1) is preferably an epoxy resin. It is preferable to mix 1.0 to 20% by weight with respect to the total amount of the resin in the composition. Specifically, the total amount of the resin is the total amount of the epoxy resin in the epoxy resin composition and the resin blended as the curing agent. When the compounding amount of the curing accelerator having the skeleton of the above formula (1) is less than 1.0% by weight based on the total amount of the resin, the storage stability by using the one of the above formula (1) as the curing accelerator. The effect of improvement cannot be obtained sufficiently. On the other hand, if it exceeds 20% by weight, the fluidity during molding of the epoxy resin composition deteriorates, which is not preferable.

The amount of the inorganic filler is preferably in the range of 60 to 93% by weight based on the total weight of the epoxy resin composition. If the blending amount of the inorganic filler is less than 60% by weight based on the total amount of the epoxy resin composition, the molded article using the epoxy resin composition will have a large amount of moisture absorption, resulting in poor moisture absorption resistance. On the other hand, if the content exceeds 93% by weight, the fluidity during molding of the epoxy resin composition deteriorates, which is not preferable.

Further, a semiconductor device can be obtained by sealing the semiconductor such as an IC by low pressure transfer molding the epoxy resin composition obtained as described above.

[0020]

The present invention will be described below in detail with reference to examples.

The compounds shown in Tables 1 and 2 were uniformly mixed by a mixer, and then heated and kneaded with a kneader to obtain epoxy resin compositions for semiconductor encapsulation of Examples 1 to 9 and Comparative Examples 1 to 4. Was.

Here, in Tables 1 and 2, "E" manufactured by Sumitomo Chemical Co., Ltd. was used as an o-cresol novolak type epoxy resin.
SCN195XL "(epoxy equivalent 195) as a biphenyl type epoxy resin" YX400 "manufactured by Yuka Shell Co., Ltd.
"OH" (epoxy equivalent 192), "ESB400" (epoxy equivalent 400) manufactured by Sumitomo Chemical Co., Ltd. as a brominated epoxy resin, and "Tamanol 752" (hydroxyl equivalent 105) manufactured by Arakawa Chemical Co. as a phenol novolak resin.
And “HE100C” (hydroxyl equivalent 169) manufactured by Sumikin Chemical Co., Ltd. as a phenol aralkyl resin, and “350” manufactured by San Apro Co. as a curing accelerator having a skeleton of the formula (1).
3N "was used. Fused silica treated with γ-glycidoxypropyltrimethoxysilane was used as an inorganic filler.

The gel time of the epoxy resin composition obtained as described above was measured at a mold temperature of 170 ° C. using “Culastometer” manufactured by Nippon Synthetic Rubber Co., Ltd. The spiral flow of the epoxy resin composition obtained as described above was measured at a mold temperature of 170 ° C. using a mold conforming to EMMI. Further, the storage stability of the epoxy resin composition obtained as described above was measured. The shelf life was measured by measuring the initial spiral flow value measured before the epoxy resin composition was allowed to stand in a thermo-hygrostat at 25 ° C. and 60% RH for 96 hours, and the spiral after the test measured after the epoxy resin composition was allowed to stand. It was performed by calculating the spiral flow deterioration rate from the flow value as in the following equation.

Spiral flow deterioration rate = (spiral flow value after test) / (initial spiral flow value) × 1
The results are shown in Tables 1 and 2.

[0025]

[Table 1]

[0026]

[Table 2]

As can be seen from the column of spiral flow deterioration rate in Tables 1 and 2, the temperature of each of the Examples was 25 ° C., 60 ° C.
Even when the epoxy resin composition was left in an environment of% RH for 96 hours, the spiral flow was little reduced, and it was confirmed that the storage stability at room temperature was excellent and the pot life was long.
The gel times of Comparative Examples 1 and 2 were too long to measure the spiral flow. Further, it is confirmed that each of the examples has excellent storage stability, but also has good performance in gel time and spiral flow.

[0028]

As described above, the first aspect of the present invention relates to an epoxy resin composition for semiconductor encapsulation containing an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler as essential components. Since a cresol novolak type epoxy resin, a phenol novolak resin as a curing agent, and a compound having a skeleton of the above formula (1) as a curing accelerator are respectively blended, an o-cresol novolak type epoxy resin is used as an epoxy resin. By using a phenol novolak resin as a curing agent and a compound having a skeleton of the above formula (1) as a curing accelerator, there is no need to microencapsulate the curing accelerator,
The storage stability at room temperature can be improved and the pot life can be extended.

Further, the invention of claim 2 provides a curing accelerator having a skeleton of the above formula (1) in an amount of from 1.0 to 20% based on the total amount of the resin.
Since the composition is blended by weight, high storage stability can be obtained and the reactivity required for molding can be sufficiently ensured.

According to the third aspect of the present invention, the inorganic filler is blended in an amount of 60 to 93% by weight with respect to the total amount of the composition. It can improve the performance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme coat ゛ (Reference) H01L 23/29 H01L 23/30 R 23/31 F-term (Reference) 4J002 CC04X CD06W CE00X DE147 DJ007 DJ017 ET016 EU096 EU116 EW016 FD017 FD14X FD156 GQ05 4J036 AA04 AF08 DA01 DA02 DC25 DC40 DC46 DD07 FA01 FA03 FA05 FB08 JA07 4M109 AA01 BA01 CA21 EA03 EB03 EB04 EB06 EB07 EB08 EB12 EB13 EB19 EC01 EC03 EC14

Claims (4)

[Claims] 1. An epoxy resin composition for semiconductor encapsulation containing an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler as essential components, wherein an o-cresol novolac type epoxy resin is used as an epoxy resin, and a phenol is used as a curing agent. Novolak resin is used as a curing accelerator in the following formula (1)
An epoxy resin composition for encapsulating a semiconductor, comprising a compound having a skeleton of the formula: Embedded image 2. The semiconductor encapsulation according to claim 1, wherein a curing accelerator having a skeleton represented by the formula (1) is compounded in an amount of 1.0 to 20% by weight based on the total amount of the resin. Epoxy resin composition. 3. An inorganic filler is used in an amount of 60 to 60% based on the total amount of the composition.
The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the composition is 93% by weight. 4. A semiconductor device comprising a semiconductor encapsulated with the epoxy resin composition according to claim 1.