JPS5927945A - Liquid epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent moisture resistance and chemical bondability, by blending an inorg. filler having a surface treated with a silane compd., with a mixture consisting of a liquid epoxy resin, an acid anhydride and a silane coupling agent. CONSTITUTION:The surface of an inorg. filler (E) such as crustalline silica powder is treated with a silane compd. (D) of formula II, III or IV (wherein R, R', R'' are each a 1-6C alkyl, phenyl; R1 is H, a 1-6C alkyl). The surface- treated filler is blended with a mixture consisting of a liquid epoxy resin (A), an acid anhydride (B) such as methyltetrahydrophthalic anhydride, and a silane coupling agent (C) of formula I (wherein Y is a monovalent org. group having an oxirane ring; R2 is a 1-5C alkyl) in weight ratios of E/A of 1-6, D/C of 0.3- 10, and C+D/E of 0.15-2.0/100.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid epoxy resin composition with excellent moisture resistance for sealing semiconductor devices.

More specifically, the inorganic filler that makes up the liquid epoxy resin composition is surface-treated with a silane compound to make it water repellent, and the silane filler is used to strengthen the bond between the surface-treated inorganic filler and the epoxy resin. This invention relates to a liquid epoxy resin composition containing a coupling agent and having excellent moisture resistance and chemical bonding properties.

Conventionally, semiconductor devices have been packaged with hermetic sealing or resin sealing in order to protect them from the external environment and mechanical shock. Currently, packages sealed with epoxy resin compositions are widely used, except for some special applications, due to both technical and cost considerations.

However, resin sealing has the disadvantage of being inferior in moisture resistance compared to hermetic sealing, and causes corrosion of aluminum wiring and pads of semiconductor elements. The reason for this is thought to be that impurities contained in the resin composition react with water and become ionized, and the generated impurity ions, particularly chlorine ions, cause corrosion.

Since it is difficult and virtually impossible to completely remove impurities during the production of resin compositions, in order to improve the moisture resistance of resin sealing, it is necessary to The key point is to prevent the reaction between the resulting impurities and water.

Conventionally, as a method to control the resin-inorganic photoresist interface and improve moisture resistance, the surface of the inorganic photoresist side of a solid tablet was directly treated with an interfacial treatment agent, and then treated with a heated roll of epoxy resin. They were mixed to produce an epoxy resin composition for semiconductor encapsulation.

However, as the amount of surface treatment agent used increases, the bonding property with the epoxy resin deteriorates and the mechanical strength of the epoxy resin composition decreases, so the amount of surface treatment agent used is only a small amount compared to the inorganic photonic agent. As a result, unevenness occurs on the surface of the inorganic optical fiber, causing moisture resistance to deteriorate in a relatively short period of time.

In view of this problem, the present inventors have prepared a hydrophobic group as a surface treating agent. By using a silane compound, a silane coupling agent of the same type as a surface treatment agent is used as a coupling agent in order to develop water repellency on the inorganic optical fiber side surface and to strengthen the bond with the epoxy resin.
We discovered scales with significantly enhanced moisture resistance and chemical bonding properties, and completed the present invention.

That is, the present invention provides a liquid epoxy resin composition for semiconductor encapsulation comprising a liquid epoxy resin, an acid anhydride, an inorganic photonic agent, a silane compound, and a silane coupling agent. billion): R81 (OR
yo>3(1) RR'5i(ORyo>2(n) RR'u"5t(oR) 100,000,000) (In the formula, R, R' and R" are an alkyl group having 1 to 6 carbon atoms or phenyl R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. % (wherein, Y is a monovalent organic group having an oxirane ring, 1'
A liquid epoxy resin composition for semiconductor encapsulation, characterized in that it is added to a mixture of a silane coupling agent (I2 represents an alkyl group having 1 to 5 carbon atoms), an epoxy resin, and an acid anhydride. It is about things.

In addition, since the epoxy resin composition of the present invention is liquid, the inorganic photonic agent, silane coupling agent, epoxy resin, and acid anhydride that have been surface-treated with a silane compound are uniformly blended, so that the surface of the inorganic photonic side is uniformly blended. It also has the effect of eliminating spots and improving moisture resistance.

The ratio of the silane compound (A) and the silane coupling agent (B) used is preferably (A)/(B) = 0.3 to 100. (A) / (B) =
When it is larger than 1o, bonding with the epoxy resin becomes difficult to occur, the mechanical strength is significantly reduced, and the corrosion inhibiting effect is reduced. Further, if (A)/(B) = less than 0.3, the water repellency of the inorganic photonic side surface will be poor and the corrosion inhibiting effect will be reduced, both of which are not preferred.

The usage amount (A) + (B) of the silane compound (A) and silane coupling agent (B) is 0 based on the weight of the inorganic photonic agent.
．． It is preferably within the range of 15 to 2.0%.
If it is less than 15% by weight, internal penetration of moisture cannot be sufficiently prevented and the corrosion inhibiting effect will be reduced. Also 2.0% by weight
If the amount is higher than that, excess silane compound (A) and silane coupling agent (B) will be liberated due to high temperature and high humidity, promoting corrosion, which is not preferable.

General formula (I) having a hydrophobic group in the molecule used in the present invention
), (II) and (Ill) include, for example, methyltrimethoxysilane,
Methyltriethoxysilane, dimethyldimethoxysilane, dimethyljethoxysilane, trimethylmethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyldimethylethoxysilane, triphenylmethoxysilane, phenyltrimethoxysilane Examples include pentoxysilane and triphenylsilanol, and the surface of the inorganic filler is directly treated using a Henschel mixer.

Silane coupling agent (B) represented by general formula (5))
For example, r-glycidoxyprobyltrimethoxysilane, β-(3,4-epoxycyclohexyl)
Examples include ethyltrimethoxysilane and r-glycidoxypropyltribenoxysilane.

Examples of the inorganic filler in the present invention include crystalline silica powder, fused silica powder, glass fiber, and alumina, and epoxy resin 1o.

It is preferable to use about 1 part by weight of 100 to +500 parts by weight.

Epoxy resins used in the present invention include those having two or more epoxy groups in the molecule, such as liquid bisphenol A epoxy resin, liquid phenol novolac epoxy resin, liquid cresol novolac epoxy resin, or liquid alicyclic epoxy resin. are preferred, and one or more of these can be used in combination.

As the acid anhydride, liquid acid anhydrides such as methylhexahydrophthalic anhydride and/or methyltetrahydrophthalic anhydride are most preferably used; Phthalic acid and the like can also be used.

In addition, the epoxy resin composition for semiconductor encapsulation of the present invention may further contain a curing accelerator, a mold release agent, a coloring agent, a flame retardant, and the like as appropriate. Examples of curing accelerators include imidazole compounds and tertiary amines, and release agents include natural waxes, synthetic waxes, metal salts of straight chain fatty acids, esters,
Examples include acid amides. Further, as the flame retardant, a combination of brominated epoxy resin and antimony trioxide is preferably used, and as the coloring agent, carbon plaque and the like can be used.

Next, Examples and Comparative Examples of the present invention will be described.

Examples 1 to 9 and Comparative Examples 1 to 9 Using fused silica powder and crystalline silica powder as inorganic fillers, a silane compound was directly treated with a Henschel mixer. Next, a silane coupling agent was added to a mixture of an epoxy resin and an acid anhydride to obtain a mixture in which the silane coupling agent was uniformly dissolved. The above-mentioned inorganic filler is blended into this mixture, a curing accelerator, a mold release agent, a coloring agent, and a retarding agent are blended as appropriate, and the mixture is mixed under reduced pressure at 140°0 for 10 minutes using a kneader to form a liquid epoxy resin for semiconductor encapsulation. I got the composition. Table 1 shows the composition ratios of each example, and Table 2 shows the composition ratios of each comparative example. In Tables 1 and 2, the silane compounds and silane coupling agents are expressed in weight percent relative to the inorganic filler, and the others are expressed in parts by weight. Note that the epoxy resin of Comparative Example 3 is solid.

Silicon elements for moisture resistance evaluation were molded using the epoxy resin compositions for soil with semiconductors shown in Tables 1 and 2 under molding conditions of 170° for 0.3 minutes. Furthermore, it is 170°
It was post-cured for 8 hours and used as a sample for a moisture resistance test.

Moisture resistance, test is P(FT (Pres8ure Cook
The failure occurrence time was investigated under the condition of 121°012 atm. The results are shown in Tables 3 and 4.

Reference Example As a reference example, a moisture resistance test (PQT') of a silicon element for moisture resistance evaluation which was transfer molded using a commercially available product (resin for solid transfer mold).

The results are shown in Table 5.

As is clear from Tables 3, 4 and 5, the epoxy resin composition for semiconductor encapsulation obtained by the present invention is as follows:
It was found to have excellent moisture resistance.

Table 4 Table 5 Procedural amendment (spontaneous) Indication of the Civic Agency Commissioner's Palace case Patent application 1984-1! +765B Title of the invention Liquid epoxy resin composition for sealing a conductor Person making the amendment Representative Kata Yuhito Department' (Representative 5, Subject of amendment (1) Column 6 of "Detailed description of the invention" of the specification Contents of the amendment (1) On page 6, lines 12-16 of the specification, "reacting with" is amended to "under the influence of minutes."

(2) On page 6, line 19, the answer to the question ``impurities and water that occur is corrected to ``and impurity ions that enter from within the resin.''

(8) Delete "solid tablet-like" from lines 2 and 3 on page 4.

(4) Delete ``Increasing the amount of the surface treatment agent used deteriorates the bonding properties with the epoxy resin and reduces the mechanical strength of the epoxy resin composition'' on page 4, lines 7 to 9.

(5) Tables 1 and 2 on pages 12 to 15 are amended as follows.

Claims (1)

[Scope of Claims] (1) A liquid epoxy resin composition for semiconductor encapsulation comprising a liquid epoxy resin, an acid anhydride, an inorganic filler, a silane compound, and a silane coupling agent, which has the general formula (1) ), (II) and @): R51 (OR) 3
(I) Lung'5i (OR) 2 (II) RR'R''5i (OR) (1) (in the formula, R,
R' and R/7 represent an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
an inorganic filler surface-treated with at least one type of silane compound represented by (representing 5 alkyl groups),
General formula % Formula % () (wherein, Y is a monovalent organic group having an oxirane ring, R2
represents an alkyl group having 1 to 5 carbon atoms) A liquid epoxy resin composition for semiconductor encapsulation, characterized in that it is added to a mixture of a silane coupling agent represented by 1 to 5 carbon atoms, an epoxy resin, and an acid anhydride. . (2) The liquid epoxy resin composition for semiconductor encapsulation according to claim (1), wherein the acid anhydride is methyltetrahydrophthalic anhydride and/or methylhexahydroheptalic anhydride. (8) The silane compound (A) and the silane coupling agent (B) are blended in a weight ratio of (A)/(B) = 0.3 to 10, and this blend has a weight ratio of 0.3 to 10 to the inorganic filler. The liquid epoxy resin composition for semiconductor encapsulation according to claim (1) or (2), wherein the composition is mixed in a range of .15 to 2.0% by weight.