JPS627721A - Semiconductor sealing material - Google Patents

Abstract

PURPOSE:To provide the titled material of high performance in both heat cycle and pressure cooker characteristics, comprising flexible liquid epoxy resin, filler, and curing agent, with its cured product limited in both contents of Na<+> and Cl<-> ions. CONSTITUTION:The objective sealing material comprising (A) 100pts.wt. of a liquid epoxy resin including flexible one (e.g., polybutadiene-modified epoxy resin), (B) pref. 20-30pts.wt. of filler (e.g., molten silica), and (C) a curing agent (an acid anhydride or aromatic amine) with its cured product containing <=10ppm of Na<+> ion and <=300ppm of Cl<-> ion and having a Shore D hardness pref. 50-80. For limiting the contents of Na<+> and Cl<-> ions, it is recommended that the resin A be purified to effect the contents of the Na<+> and Cl<-> ions <=1ppm and <=500ppm, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor encapsulation material, and particularly to a semiconductor encapsulation material that has a good balance between heat cycle properties and PCT properties.

[Prior art]

Conventionally, ceramic encapsulation and can encapsulation have been used as semiconductor encapsulation materials, but in recent years resin encapsulation has begun to be used, and Scheffexy resin has become widely used due to its economic efficiency and characteristics. It's here.

Such epoxy resins for semiconductor encapsulation are used by blending cresol novolac epoxy resins, alicyclic epoxy resins, phenol resins, amines, etc. It is difficult to harmonize the PCT characteristics, and if emphasis is placed on PCT characteristics, there are many problems such as cracks occurring during heat cycles.

[Purpose of the invention]

As a result of various studies to improve PCT properties and heat cycle properties, which were previously insufficient, the inventors of the present invention suppressed the content of Na-1 and Cl-1 in epoxy resin compositions and Gives flexibility □ PC from K
The present invention was completed by reaching the conclusion that both T characteristics and heat cycle properties could be maintained well.

[Structure of the invention]

The present invention relates to a thermosetting resin composition comprising a liquid epoxy resin including a flexible liquid epoxy resin, an acid-free □hydrate or an aromatic amine as a filler and a hardening agent, A semiconductor encapsulating material characterized in that the cured product has an Na+ content of 10 ppm or less and a ct- content of 300 ppm or less. The flexible liquid epoxy resin used in the present invention is not particularly limited as long as it has flexibility and has two or more epoxy groups in the molecule, but it has a Na content of 1 ppm or less, a Cl content of 1 ppm or less,
- The content is preferably 500 ppm or less. Examples of such flexible liquid epoxy resin include hibutadiene-modified epixy resin, rubber-modified niboxy resin, and urethane-modified epoxy resin. Although these flexible liquid epoxy resins may be used as they are, they are usually used as a mixture with a liquid epoxy resin.

The liquid epoxy resin used here is not particularly limited as long as it has two or more epoxy groups in the molecule like the above-mentioned flexible liquid epoxy resin, but the Na+ content is 1
Preferably, the Cl- content is 500 ppm or less. Examples of such epoxy resins include novolac type epoxy resins, bisphenol A glycidyl type epoxy resins, bisphenol F glycidyl ether type epoxy resins, and fatty m type epoxy resins. The filler may be alumina, silica, etc., of which fused silica, which has low water absorption, is most suitable. Its particle size is 1-10
o and y are preferably used. The amount added is preferably 20 to 300 parts by weight based on 100 parts by weight of the total epixy resin. As the curing agent, acid anhydride or aromatic amine is used.

In the epoxy resin composition of the present invention, a cured product having appropriate flexibility can be obtained, but one having a sear D hardness of 50 to 80 is optimal.

In addition to the above components, the present invention also includes the addition of reactive diluents, pigments, thixotropy imparting agents, and the like.

The Nixi resin composition of the present invention has a cured product with an Na+ content of 10 ppm or less and a ct- content of 300 ppm.
It is necessary that the following is true. Among the components of the composition of the present invention, the epoxy resin has a high content of CL- in Na, while the other components have a low content of Cl- in Na and can be virtually ignored.

In the present invention, it is necessary to refine the eixy resin to reduce Na and Cl to as much as possible, but as mentioned above, it is preferable that the Na content is 1 ppm or less and the Cl content is 500 ppm or less. Na+ content in the substance is 1
The reason for setting the Cl- content to 0 ppm or less and 300 ppm is because if Na contains more Cl-, it tends to contaminate the semiconductor element and shorten the reliability life of the semiconductor element. It is.

〔Effect of the invention〕

The present invention has the following effects.

1. Since the content of Na'' and Cl- is low, the amount of water absorbed in PCT is very small, making it optimal for protecting semiconductor devices. It is even more preferable to use fillers with low water absorption.

2. Since the Eixy resin has flexibility, it has excellent heat cycle properties, and stress is not directly transmitted to the semiconductor element, so there is no risk of destroying the semiconductor element.

3. It has excellent PCT characteristics and heat cycle properties, making it ideal as a semiconductor encapsulation material.

〔Example〕

As Examples 1 and 2 and Comparative Example 1, epoxy resin compositions having the following formulations were used. "Parts" represent "parts by weight."

Example 1 100 parts of pybutadiene-modified niboxy resin
= (Epoxy equivalent weight 370) Hexahydrophthalic anhydride 50 parts 2
-Ethyl-4-methylimidazole 2 parts fused silica 200 parts N in hardened material
a” 3 ppmCL-250
ppm Example 2 Bisphenol F type edexy resin 75 parts (
Epoxy equivalent: 170) Aliphatic alkyl-modified bisphenol A 25 parts Nixi resin (Epoxy equivalent: 325) Diaminodiphenylmethane 30 parts DMP-30 3 parts Fused silica 200 parts N in cured product
a+45 ppm C1280ppm Comparative Example 1 Bisphenol A type epixy resin 100 parts (
Epoxy equivalent: 190) Hexahydrophthalic anhydride 80 parts 2
-Ethyl-4-methylimidazole 2 parts Calcium carbonate 200 parts Na+ in cured product
23 ppm C1-650 ppm The Nixy resin used in the examples was purified and Na
+ and Cl- less than 1 ppm and 500 ppm, respectively
m or less was used.

The resin compositions of Example 1.2 and Comparative Example 1 were
The mixture was injected into a 10 sm case, cured at 120°C for 3 hours, and used as Su/Pull.

As shown in Table 1, in terms of PCT characteristics, the resin composition of Comparative Example 1 dissolved after 65 hours, but the resin composition of Example 1.2 each dissolved by 0.58% after 100 hours. , 1.18chi, which is an extremely excellent value. As shown in Table 2, in the heat cycle test, all cracks occurred in Comparative Example 1 after 75 cycles, but no cracks were observed in Example 1.2 even after 100 cycles.

Table-1 Water absorption rate in pressure shock test: 2.1 atm 125℃ Table-2 Number of samples in heat shock test Number of samples: 20 Conditions Knee 55℃ 1 hour 4 + 150℃ 1 hour Procedure amendment (voluntary) Showa August 9, 1960

Claims (1)

[Claims] A thermosetting epoxy resin composition comprising a liquid epoxy resin including a flexible liquid epoxy resin, a filler, and an acid anhydride or an aromatic amine as a hardening agent, the cured product of this composition containing Na^+ The amount is 10 ppm or less, Cl^-
A semiconductor encapsulation material having a content of 300 ppm or less.