JPH03205443A - Sealing resin composition and semiconductor sealing apparatus - Google Patents

Abstract

PURPOSE:To obtain the title compsn. excellent in the thermal properties, moisture resistance, moldability, and mechanical properties by compounding specific resins, a specific disilane compd., and a specified amt. of a whisker as the essential components. CONSTITUTION:The title compsn. is prepd. by compounding an epoxy resin (e.g. a cresol novolac epoxy resin), a novolac phenol resin, a methyl methacrylate-butadiene-styrene copolymer; a disilane compd. of the formula (wherein R is CH3 or phenyl, X is a group reactive with an epoxy group, Y is a group reactive with a phenolic hydroxyl group, and n>=3), and a beta-silicon nitride whisker having an aspect ratio of 20-50 in an amt. of 25-90wt.% based on the total compsn.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides an epoxy-based material with a good balance of properties, which has a small coefficient of thermal expansion, high thermal conductivity, excellent moisture resistance, and moldability. The present invention relates to a semiconductor sealing device sealed with a sealing resin composition and a cured product thereof.

(Prior Art) Conventionally, methods have been used to seal electronic components such as diodes, transistors, and integrated circuits using ripe hardening resins. This resin sealing is economically advantageous compared to hermetic sealing methods using glass, metal, or ceramic, and is therefore widely put into practical use. Among thermosetting resins, epoxy resin is most commonly used as the sealing resin in terms of reliability and cost. For epoxy resins, curing agents such as acid anhydrides, aromatic amines, and novolac-type phenolic resins are used. Among these, epoxy resins that use novolac-type phenolic resin as a curing agent are preferred as resins for semiconductor encapsulation because they have excellent moldability and moisture resistance, are nontoxic, and are inexpensive compared to those that use other curing agents. It is widely used as Further, as a filler, fused silica powder and crystalline silica powder are most commonly used together with the above-mentioned curing agent. In recent years, with the increasing density and power consumption of semiconductor components, there has been a demand for semiconductor encapsulation resins with better heat dissipation properties.

(Problems to be Solved by the Invention) However, a resin composition made of an epoxy resin using a novolac type phenol resin as a curing agent and fused silica powder has a thermal expansion Il! Although it has the characteristics of a small coefficient, good moisture resistance, and excellent resistance to bonding wire opens, resin cracks, and P1/T1~ cracks in hot and cold cycle tests, heat dissipation is poor due to low mature conductivity. Unfortunately, power semiconductors that consume large amounts of power have the disadvantage that they cannot perform their functions. On the other hand, for resin composites made of epoxy resin using novolac-type phenolic resin as a curing agent and crystalline silica powder, increasing the blending ratio of crystalline silica powder increases the conductivity and improves heat dissipation. However, it has the disadvantage of having a large coefficient of thermal expansion and poor reliability in moisture resistance.

Furthermore, the sealed crystal using this resin composition has the disadvantage that mechanical properties and shapeability are deteriorated. Therefore, there is a natural limit to the ability to increase the thermal conductivity of sealing resin composites using silica powder.

The present invention has been developed in order to eliminate the above-mentioned drawbacks, so it has excellent thermal conductivity, moisture resistance, formability, small coefficient of thermal expansion, good heat dissipation, and good mechanical strength, and has a good balance of these properties. It is an object of the present invention to provide a good and highly reliable sealing resin composition and semiconductor sealing device.

[Elements of the Invention] (Means for Solving the Problems) As a result of extensive research in an attempt to achieve the above object, the present inventor has developed a methyl methacrylate-butadiene-styrene copolymer resin, a specific disilane compound and It has been found that the above object can be achieved by blending a specific β silicon nitride whisker, and the present invention has been completed.

That is, the present invention comprises (A"l epoxy resin, (B) novolac type phenol resin, (C) methyl methacrylate-butadiene-lene copolymer resin, <D) a disilane compound having the following general formula, , in the formula, R represents a methyl group or a phenyl group, X represents a substituent that reacts with an epoxy group, Y represents a substituent that reacts with a phenolic hydroxyl group, and n represents an integer of 3 or 2, respectively) E) β silicon nitride whiskers having an aspect ratio of 20 to 50 are essential, and the resin composition contains 25 to 90% by weight of the β silicon nitride whiskers of (E) above. A semiconductor sealing device characterized in that a semiconductor device is sealed with a sealing resin assembly and a cured product thereof.

6 The epoxy resin (A) used in the present invention is a compound having at least two epoxy groups in its molecule, and there are no particular restrictions on molecular ellipse, molecular weight, etc., and commonly used epoxy resins may be used. Can be broadly encompassed. Examples include aromatic resins such as bisphenol type, alicyclic resins such as cyclohexane derivatives, and epoxy novolac type epoxy resins represented by the following general formula.

(However, in the formula, R1 represents a hydrogen atom, a halogen atom, or an alkyl group, R2 represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins are used alone or in a mixture of two or more. .

The (B) novolac type phenolic resin used in the present invention includes novolac type phenol resins obtained by reacting phenols such as phenol and alkylphenols with formaldehyde or paraformaldehyde, and modified resins thereof, such as epoxidized or butylated novolak types. Examples include phenol resins, and these may be used alone or in combination of two or more. The blending ratio of the novolac type phenolic resin is determined by the molar ratio of the epoxy group (a) of the above (A) epoxy resin and <B) the phenolic hydroxyl group (b) of the novolac type phenolic resin [(a)/(b) ]
is o. Luco is desirable within the range of i to io. If the molar ratio is less than 0.1 or more than 10, the moisture resistance, moldability and electrical properties of the cured product will deteriorate, and either case is unfavorable.

The methyl methacrylate/butadiene/styrene copolymer resin (C) used in the present invention may be a copolymer of methyl methacrylate 1-1, butadiene, and styrene, and is not limited to the composition or ratio of each monomer. do not have.
The blending ratio of methyl methacrylate 1 to butadiene styrene copolymer resin is 0.1 to 10 to the resin composition.
It is desirable to contain it in a proportion of % by weight. If the proportion is less than 0.1% by weight, there will be no effect of lowering the elasticity;
If it exceeds 0% by weight, the shapeability is poor and undesirable. The method of blending the methyl methacrylate-ptadiene-styrene copolymer resin, which is preferably in the range of 1.0 to 5.0% by weight, is not particularly limited, but it is possible to uniformly disperse it in the novolac type phenolic resin. It is preferable to leave it.

As the <D> disilane compound used in the present invention, one having the following general formula is used.

However, in the formula, R is a methyl group or a phenyl group, and X bonded to the polymethylene group (n≧3) is a substituent that reacts with an epoxy group, specifically -OH, -SH, -SSR3
-NH2, -NHR', anhydrous phthalate, etc. (here R
3, R'' represents an alkyl group), and Y bonded to the polymethylene group (n≧3) is a substituent 9 that reacts with a phenolic hydroxyl group, specifically 100OH, 1NGO.

Specific examples of disilane compounds include:
These can be used alone or in combination of two or more. The disilane compound is desirably contained in a proportion of 0.01 to 5% by weight based on the resin composition. If the proportion is less than 0.01% by weight, the surface treatment for the β silicon nitride whiskers will not be appropriate, and if it exceeds 5% by weight, the surface of the β silicon nitride whiskers will be easily decomposed by moisture, which is undesirable. . It is preferably within the range of 0.1 to 1.0% by weight.

(E) β with an asbec ratio of 1 to 20 to 50 used in the present invention
As a silicon nitride whisker, the diameter of the whisker is 0.
．． It is desirable to have a 5 to 1.5 μm mark, a length of 10 to 30 μm, and an aspect ratio of 20 to 50. If the diameter of the whisker is less than 0.5 μm or more than 1.5 μm, it is not preferable because it reduces workability in manufacturing. In addition, if the length of the whisker is less than 10 μ■, the mechanical strength will be insufficient, and 30
If it exceeds μm, wire flow may occur during molding, which is not preferable. Therefore, whiskers having an aspect ratio of 20 to 50 are preferred. The blending ratio of the β silicon nitride whiskers is preferably 25 to 90% by weight based on the resin composition. If the proportion is less than 25% by weight, the thermal expansion is I1! It is undesirable because it has a large coefficient, low thermal conductivity, and weak mechanical strength. Moreover, if it exceeds 90% by weight, bulkiness is large and moldability is poor, making it unsuitable for practical use.

Sealing resin assembly of the present invention e. ′! lJ is epoxy resin,
Novolac type phenolic resin, methyl methacrylate
The essential components are a ptadiene-styrene copolymer resin, a disilane compound, and a β-silicon nitride whisker, but natural waxes, synthetic waxes, and straight chain fatty acids may be added as necessary to the extent that it does not contradict the purpose of the present invention. Mold release agents such as metal salts, acid amides, esters, paraffins, etc.
Flame retardants such as chlorinated paraffin, bromotoluene, hexabromobenzene, and antimony dioxide, colorants such as carbon black and pen color, various hardening agents, etc. can be appropriately added and blended into the sealing resin composition of the present invention. General methods for preparing materials as molding materials include epoxy resins, novolac type phenolic resins, methyl methacrylate/butadiene-styrene copolymer resins, disilane compounds, β-silicon nitride whiskers, and other materials. After mixing the raw materials selected with a composition ratio of It can be crushed and made into a shape material. The thus obtained shaped material can provide excellent properties and reliability when applied to sealing, covering, insulating, etc. electronic or electrical components including semiconductor devices.

The semiconductor encapsulation device of the present invention can be easily manufactured by encapsulating a semiconductor device using the above-mentioned encapsulation resin assembly. The semiconductor device to be sealed may be, for example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, etc., but is not particularly limited.
The most common method of sealing is a low-pressure transfer or molding method, but sealing by injection molding, compression molding, casting, etc. is also possible. After the sealing resin composition is shaped, it is further heated to be post-cured, and finally a semiconductor sealing device sealed with a cured composite is obtained. For post-curing by heating, it is preferable to heat and cure at 150° C. or higher.

(Examples) The present invention will be specifically explained by examples, but the present invention is not limited to the following examples.

In Examples and Comparative Examples, "%j" means 13 Means "% by weight".

Example l Cresol novolac epoxy resin <epoxy per i 2
15) 16%, novolak type phenolic resin (phenol equivalent: 107), 8%, β silicon nitride whiskers
(Asbec 1 to ratio 30, average diameter 1.0μl'N) 71%
, 2% of methyl methacrylate/gutagene/styrene copolymer resin, 0.5% of a disilane compound represented by the following formula, and 2.5% of a mold release agent were mixed at room temperature, and
The mixture was kneaded at 95° C., cooled and ground to produce a shaped material.

Example 2 In Example 1, β silicon nitride whiskers (average diameter 1.0 μIn) were used instead of single β silicon nitride whiskers.
31% and crystalline silica powder (average particle size 38 μm) 40%
A molding material was produced in the same manner as in Example 141 except that the mixed system was used.

Comparative Example 1 16% of cresol novolak epoxy resin (.T. boxy equivalent: 215), 8% of novolak type phenol resin (phenol equivalent: 107), 2.0% of methyl methacrylate-butadiene-styrene copolymer resin, expressed by the following formula. 0.5% disilane compound, fused silica powder 71
A molding material was produced in the same manner as in Example 1, except that the mold release agent and the like were 2.5%.

Comparative Example 2 A shaped material was produced in the same manner as in Comparative Example 1 except that crystalline silica powder (average particle size of 28 μm) was used instead of fused silica powder.

Comparative Example 3 Cresol nophorac epoxy resin (i 2 per epoxy
15) 18%, novolak type phenolic resin 15 (phenol equivalent: 107) 9%, β silicon nitride whiskers (Asbec 1 to 30 ratio, average diameter 1.0 μm) 70
A molding material was produced in the same manner as in Comparative Example 1 with the addition of 3% and 3%.

Comparative Example 4 A molding material was produced in the same manner as in Comparative Example 3 except that silicon nitride powder (average particle size 17 μ+n) was used instead of β-nitride and diagonal whiskers.

Examples 1 to 2 and Comparative Examples 1 to 4! ! ! A semiconductor device was manufactured by sealing the semiconductor device using the leftover molded material and curing it at 170°C. Various tests were conducted on certain materials and semiconductor encapsulation devices, and the results are shown in Table 1. The present invention has good thermal properties, moisture resistance, and shapeability, and the effects of the present invention were confirmed.

1 6 No. 1 table (unit *2: *3: ．． Measured according to JII S-K-6 9 1 1.

A rapid thermal conductivity meter (manufactured by Showa Denko,
A 16-pin DI with 120 cavities was measured at room temperature using the product name QTM-MD.
Using a P mold, transfer molding was carried out at 170° C. for 3 minutes to test the filling property.

○ mark: Good, △ mark: Poor.

17 *4: A semiconductor device having two aluminum wirings was transfer-molded using a molding material at 170'C for 3 minutes, and then cured for 8 hours. A moisture resistance test was conducted on 100 of these semiconductor sealing devices in high-pressure steam at 120° C., and the time required for 50% disconnection (defect generation) due to aluminum corrosion was evaluated.

[Effects of the Invention] As is clear from the above explanation and Table 1, the encapsulating resin composition and semiconductor encapsulating device of the present invention have excellent thermal properties, moisture resistance, and moldability, and are mechanically resistant. It has good physical characteristics, good balance of characteristics, and high reliability.

1 8

Claims (1)

[Scope of Claims] 1 (A) an epoxy resin, (B) a novolac type phenol resin, (C) a methyl methacrylate-butadiene-styrene copolymer resin, (D) a disilane compound having the following general formula, and ▲ mathematical formula, There are chemical formulas, tables, etc.▼ (However, in the formula, R is a methyl group or phenyl group, X is a substituent that reacts with an epoxy group, Y is a substituent that reacts with a phenolic hydroxyl group, and n is an integer of 3 or more. (E) β silicon nitride whiskers having an aspect ratio of 20 to 50 are an essential component, and the β silicon nitride whiskers of (E) are contained in an amount of 25 to 90% by weight based on the resin composition. A sealing resin composition characterized by: 2 (A) Epoxy resin, (B) Novolac type phenolic resin, (C) Methyl methacrylate-butadiene-styrene copolymer resin, (D) Disilane compound having the following general formula, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, R represents a methyl group or a phenyl group, X represents a substituent that reacts with an epoxy group, Y represents a substituent that reacts with a phenolic hydroxyl group, and n represents an integer of 3 or more.) (E ) A cured product of a sealing resin composition containing β silicon nitride whiskers having an aspect ratio of 25 to 50 as an essential component and containing 25 to 90% by weight of the β silicon nitride whiskers of (E) based on the resin composition. A semiconductor sealing device characterized in that a semiconductor device is sealed.