JPH0228213A - Epoxy resin composition for semiconductor sealing - Google Patents

Abstract

PURPOSE:To obtain the title composition containing a flexibilizer obtained by reacting a specific modified silicone oil with an epoxy resin, epoxy resin and curing agent, having heat resistance and moisture resistance as well as low modulus and capable of providing cured product having high glass transition point. CONSTITUTION:The aimed composition obtained by reacting a modified silicone oil expressed by the formula [R1-R4 are bivalent organic groups; R21-R27 are 1-5C alkyl, phenyl, etc.; a is 10-300; b is 0-10; 0<=b/(a+b)<=0.32] with an epoxy resin so as to afford a flexibilizer and then blending the resultant flexibilizer with an epoxy resin (e.g., cresol novolak resin type epoxy resin) and curing agent (e.g., phenol novolak resin). Furthermore, equivalent ratio of the phenolic hydroxyl group of the compound expressed by the formula with epoxy group of the epoxy resin is preferably kept to <=0.4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is applied to an epoxy resin composition for semiconductor encapsulation.

[Conventional technology]

In recent years, semiconductor devices have become more integrated, resulting in larger chip areas and thinner resins. When encapsulated with conventional epoxy resin compositions, chips may crack, bonding lines may be cut, or aluminum wiring may occur. Sliding, cracks in the encapsulating resin, etc. can cause fatal failures in semiconductor parts (1).This is because conventional epoxy resins for semiconductor encapsulation are
This is because it was developed from the viewpoint of moisture resistance, and its cured product has poor flexibility, and the stress applied to the element is large.

Generally, in order to reduce the stress of an epoxy resin for semiconductor sealing, there are two ways: to reduce the coefficient of thermal expansion of the resin to reduce thermal strain, and to lower the modulus of elasticity to reduce stress due to thermal strain. In addition, from the viewpoint of maintaining heat resistance and moisture resistance and expanding the temperature range where thermal distortion is small, it is necessary to increase the glass transition temperature. One way to reduce stress is to add a flexibilizer, but conventional flexibilizers (for example, long-chain alkylene polyamines, polyoxyalkylene glycols, bisphenol A-type diamides with long-chain alkylene oxides) The method of lowering the elastic modulus using glycidyl ether (glycidyl ether) has the disadvantage that the glass transition temperature of the cured product is significantly lowered, resulting in lower heat resistance and moisture resistance. (
Equity 1↓ Publication No. 559-8718, Special Publication No. 59-308
(No. 20, Japanese Patent Publication No. 59-226066) Polybutadiene, which has a functional group capable of reacting with an epoxy resin or a phenol resin at both ends, is used as a flexibilizing agent with a small drop in 1-sealability and glass transition temperature; Alternatively, an elastomer modifying agent obtained from a copolymer of butadiene and acrylonitrile has also been devised. (
Special Publication No. Sho 58-108220, Special Publication No. Sho 58-174
(See Japanese Patent Publication No. 416, Japanese Patent Publication No. 58-184204, Japanese Patent Publication No. 62-9248, Japanese Patent Publication No. 59-113021, Japanese Patent Publication No. 59-58024) Also, it has excellent electrical properties and thermal stability at high temperatures. Another method involves dispersing silicone resin or silicone rubber with a low elastic modulus as a flexibilizing agent. (Tokuko Showa 62-8
(Japanese Patent Publication No. 4147, Japanese Patent Publication No. 564647) [Problems to be Solved by the Invention] The above-mentioned conventional elastomer modification flexibility agents have a poor flexibility effect because the unsaturated bonds in the elastomer are oxidized and deteriorated at high temperatures. There is a problem that the silicone resin disappears, and silicone resin has poor adhesion with gold hA (frames, etc.).
Silicone oil has a weak interface with the epoxy matrix, so the moisture permeability of the cured product increases, resulting in poor moisture resistance (
However, there was a problem in that it lacked reliability due to its low mechanical strength.

The present invention has been made to solve these problems, and therefore, it is possible to obtain a cured product that has heat resistance, moisture resistance, low elastic modulus, low coefficient of thermal expansion, and a high glass transition temperature comparable to or higher than conventional products. The purpose of the present invention is to obtain an epoxy resin composition for semiconductor confinement.

[Means to solve the problem]

The epoxy resin composition for semiconductor encapsulation of this invention has the following formula: During the ceremony, R3 + R4 is a divalent organic group, ”!I+R23!”2”′\ \ It is.

It contains a flexibilizing agent, an epoxy resin, and a curing agent obtained by reacting at least one of the modified silicone oils shown in the following with an epoxy resin.

[Effect]

In this invention, the copolymer obtained by preliminary reaction between silicone oil and epoxy resin is produced by the reaction between both ends of the silicone polymer or both ends and the phenolic hydroxyl group contained within the molecule and the epoxy group in the epoxy resin. By doing so, the silicone polymer, which is the flexibilizing component, is chemically pre-bonded, and the interface between the silicone and the matrix in the cured epoxy product is strengthened.

〔Example〕

Epoxies Z and M according to the present invention include, for example, cresol novolak type epoxy resin, phenol novolac type epoxy resin, alkylbenzene-modified phenol novolac type epoxy! Examples include flL halogenated phenol novolak type epoxy resin, bisphenol A novolac type epoxy resin, multifunctional type epoxy resin such as tris(glycidoxyphenyl)methane, etc.
It is not limited to this. These may be used alone or in combination of two or more.

Further, the epoxy resin to be reacted with the modified silicone oil and the other epoxy resins may be of the same type or different types.

Examples of the curing agent according to this invention include phenol novolak resin, cresol novolak resin, alkyl-modified phenol resin, and bisphenol A novolak 1flL)-
Examples include, but are not limited to, phenolic novolak curing agents such as polyfunctional phenolic resins such as lis(hydroxyphenyl)methane. These are not limited to use alone, but two or more types can be used in combination.

Further, in the present invention, additives such as a curing accelerator (catalyst), an inorganic filler, an internal mold release agent, a surface treatment agent, a pigment, a flame retardant, and an antioxidant may be appropriately included.

The curing accelerator is not particularly limited as long as it is a common catalyst, and specific examples thereof include phosphorus compounds represented by the present sphines such as triphenylphosphine, 2-methylimidazole, and 2-ethyl- Imidazoles such as 4-methylimidazole, tertiary amines, 1,
Examples include 8-diazabicyclo(5,4,0)undecene 7 and its organic salts. These may be used alone or in combination without any problem. The amount added is desirably 1% by weight or less in the sealing resin composition. If it exceeds 1% by weight, gelation occurs too quickly and molding becomes difficult. The inorganic filler is preferably used in an amount of 250 to 1300 parts by weight per 100 parts by weight of the epoxy diencephalon.If it is less than 250 parts by weight, the strength will be low and problems will occur in terms of heat resistance and thermal shock resistance. Poor fluidity makes molding difficult. Inorganic fillers include natural silica, synthetic silica, and crushed silica in the form of
Examples include, but are not limited to, crushed quartz such as spherical silica, talc, mica, silicon nitride, and alumina.

Further, these may be used alone or in combination of two or more. In addition, fatty acids and their metal salts, internal mold release agents such as natural waxes and synthetic waxes, surface treatment agents,
Pigments such as carbon black, flame retardants such as antimony trioxide, and antioxidants are used.

The modified silicone oil according to the present invention has an alkoxy group, a phenyl group, and a carbon I! ! , 1 to 5 (-[-1, a of the fluorine-substituted alkyl group is 10 to 3
00), b is an integer from 0 to 10, 0≦b/(a+b
)≦0.32.

and R+R3, R4 are, for example, methylene,
Divalent saturated hydrocarbon groups such as ethylene, trimethylene, tetramethylene and propylene, divalent groups containing an ether bond having θ to 10 carbon atoms, phenylene groups, divalent alicyclic hydrocarbon groups, and heterocycles There are two groups, each of which may be the same or different.

Further, the number of siloxane units C in formula (1) a) is 10 to 30
If the at is smaller than 10, the effect of lowering the elastic modulus is poor, and if it is larger than 300, the reactivity with the epoxy resin is extremely small (not only does it cause a decrease in the sea-island interface) Because the strength is weak, it will cause problems in properties such as crack resistance. Therefore, in silicones with a large a value, it is desirable to have a phenolic hydroxyl group in the molecule in addition to both ends. is an integer of 0≦1)/(a+b)≦0.32, and 0.3
If it is larger than 2, gelation occurs during the preliminary reaction with the epoxy resin, making it impossible to obtain a stable flexibilizing agent.

Further, the above-mentioned modified silicone oil can be used alone or in combination of two or more kinds.

In the reaction of reacting the above-mentioned modified silicone oil and epoxy resin to obtain a flexibilizing agent, the equivalent ratio of the phenolic hydroxyl group in the phenol-modified silicone oil to the epoxy group of the epoxy resin (phenolic hydroxyl group/epoxy group)
The value of is preferably 0.4 or less. If it is larger than 0.4, gelation occurs during the preliminary reaction with the epoxy resin, making it impossible to obtain a stable flexibilizing agent. The amount of the catalyst is preferably 3 parts by weight or less per 100 parts by weight of silicone oil. The pre-reacted product synthesized in this manner is preferably one in which 70% or more of the phenolic hydroxyl groups in the silicone oil have reacted with the epoxy groups of the epoxy resin.

If the amount of the reactant is less than 70%, there will be problems such as a large decrease in strength as a semiconductor sealing material and a large weight loss when held at high temperatures for a long time.

The epoxy resin composition for semiconductor encapsulation of the embodiment of the present invention controls the amount of modified silicone oil added, and contains α3 organic components such as epoxy zone IJ&, other epoxy eye fat, and curing agent that react with the modified silicone oil. ], it is desirable that [Al/(IAI+1BI) is 3 to 20% by weight. If it is less than 3% by weight, the effect of lowering the elastic modulus of the molded product is small and the improvement in the glass transition temperature is small. On the other hand, if it exceeds 20%, the decrease in mechanical strength will be significant.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 A modified silicone oil represented by the general formula with an average molecular weight of 12 rl O and phenolic hydroxyl groups of 50 [L parts]
Epoxy weight jl (W, P, E) 170 multifunctional epoxy resin (trade name EPPN-502, Nippon Kayaku) 1
00ffiffi part and 1 part by weight of triphenylphosphine were reacted at 140°C in a nitrogen atmosphere, and a flexibilizer (1 part by weight) was reacted with 1 part by weight of triphenylphosphine.
) was obtained.

Next, the epoxy resin (EPPN502
) 81 parts by weight, epoxy equivalent (W, P-E) 2so brominated phenol novolac epoxy resin (trade name BREN
-8 Parts of Nippon Kayaku manufactured by Nippon Kayaku, phenol novolac resin with a phenolic hydroxyl equivalent of 105 added so that the total epoxy equivalent of the above epoxy resin and the phenolic hydroxyl equivalent are equal (product name PSF4261 manufactured by Gunei Chemical Co., Ltd.)
66 overlapping parts, 29 parts by weight of the above-mentioned flexibilizing agent (o), 1 part by weight of triphenylphosphine (TPP), silane coupling agent, internal mold release agent, fused silica as an inorganic filler,
Antimony trioxide and a colorant were mixed in the amounts shown in the table, and additions were made to facilitate kneading to obtain an epoxy resin composition for semiconductor encapsulation according to an embodiment of the present invention.

Examples 2 and 3 Semiconductor encapsulation of other examples of the present invention was made in the same manner as in Example 1 except that the amount of the flexibilizing agent (1) obtained in Example 1 and others were mixed as shown in the table. A stopper epoxy resin composition was obtained.

Example 4 Flexibility agent (2) was prepared in the same manner as in Example 1 except that instead of the modified silicone oil used in Example 1, a modified silicone oil represented by the general formula and having an average molecular fi of 4500 and a phenolic hydroxyl group of ff 122oo was used. An epoxy resin composition for semiconductor encapsulation according to another example of the present invention was prepared in the same manner as in Example 1 except that the flexibilizing agent (2) and others were adjusted as shown in the table.

Example 5 In place of the modified silicone oil used in Example 1, a silicone oil was used which was expressed by the monomer formula and had an average molecular weight of uooo and a phenolic hydroxyl group of 1
A flexibilizer (3) was obtained in the same manner as in Example 1 using 15600 modified silicone oil, and in the same manner as in Example 1 except that the flexibilizer (3) and others were mixed as shown in the table. An epoxy resin composition for semiconductor encapsulation according to another example of the present invention was obtained.

Example 6 In place of the modified silicone oil used in Example 1, a modified silicone oil represented by the general formula and having an average molecular weight of 11,000 and an i of 12,100 per phenolic hydroxyl group was used.
A semiconductor encapsulation according to another embodiment of the present invention was prepared in the same manner as in Example 1 except that the flexibilizing agent (4) was obtained in the same manner as in Example 1, and the flexibilizing agent (4) and others were mixed as shown in the table. A stopper epoxy resin composition was obtained.

Example 7 The flexibilizing agent (4) synthesized in Example 6 and other organic components were used in the same manner as in Example 6, and the inorganic filler was added to 1.
An epoxy resin composition for semiconductor encapsulation according to yet another example of the present invention was obtained in the same manner as in Example 1 except that 200 parts of the composition were mixed.

Comparative Example 1 A silicone oil flexibilizing agent (5) having a phenolic hydroxyl equivalent of 210 was used and mixed as shown in the table to obtain an epoxy resin composition.

Comparative Example 2 An epoxy resin composition was obtained by mixing as shown in the table without using a flexibilizing agent.

Characteristic Test Cured test pieces of the epoxy resin compositions of Examples 1 to 6 and Comparative Example 1.2 were prepared, and the mechanical properties (JISK6911
), glass transition temperature, coefficient of thermal expansion, -196℃×30se
The package crack characteristics after 100 thermal cycles of c~260°CX30SeC were measured. The results are shown in the table. As is clear from the results in the table, the cured product of the epoxy-resin composition for semiconductor encapsulation of the example of the present invention has high heat resistance, a low coefficient of thermal expansion, and a low modulus of elasticity, and is also superior to the conventional example. It can be seen that it achieves a glass transition temperature as high as or higher than that, and has moisture resistance due to the epoxy resin component, and can be suitably used for semiconductor encapsulation.

〔Effect of the invention〕

As explained above, the present invention provides: - By using a material containing a flexibilizing agent obtained by reacting an epoxy resin with at least one of the modified silicone oils represented by the formula, an epoxy resin, and a curing agent, Has heat resistance, moisture resistance, low elastic modulus, low coefficient of thermal expansion,
It is possible to obtain an epoxy t'dk composition for semiconductor encapsulation, which can produce a cured product with a glass transition temperature as high as or higher than conventional epoxy t'dk compositions.

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (In the formula, R_1, R_3, R_4 are divalent organic groups, R_
2_1, R_2_2, R_2_3, R_2_4, R_2
_5, R_2_6, R_2_7 are alkyl groups having 1 to 5 carbon atoms, hydroxyalkyl groups having 1 to 5 carbon atoms, and 1 carbon number.
~5 alkoxy groups, phenyl groups, and fluorine-substituted alkyl groups having 1 to 5 carbon atoms, a is an integer of 10 to 300, b is a number of 0 to 10, 0≦b/(a+b)≦0. 3
It is 2. ) An epoxy resin composition for semiconductor encapsulation containing a flexible agent, an epoxy resin, and a curing agent obtained by reacting at least one of the modified silicone oils shown in the following formula with an epoxy resin.