JPH03119052A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition having excellent reliability and moldability and giving semiconductor devices generating no crack when soldered by compounding an epoxy resin, a modified silicone compound, a bismaleimide compound, fused silica and a hardening agent. CONSTITUTION:An epoxy resin composition comprises (A) an epoxy resin comprising a biphenyl epoxy resin having skeletons of the formula (R<1> to R<8> are H, 1-4C lower alkyl or halogen) as an essential component, (B) a hardening agent, (C) a modified silicone compound, (D) fused silica and (E) a bismaleimide compound. The resin having the skeletons of the component A includes 4,4'-bis (2,3-epoxypropoxy) biphenyl. The components C and E are compounded in amounts of 0.3-2wt.% and 40-60wt.%, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an epoxy resin composition that has excellent solder heat resistance, reliability, and moldability, and has properties suitable for semiconductor encapsulation.

<Conventional technology> Epoxy resins have excellent heat resistance, moisture resistance, electrical properties, and adhesive properties, and can be imparted with various properties depending on the formulation, so they are used in industrial applications such as paints, adhesives, and electrical insulation materials. It is effectively used as a material.

For example, as methods for encapsulating electronic circuit components such as semiconductor devices, hermetic seals using metals and ceramics, and resin encapsulation using phenolic resins, silicone resins, and epoxy resins have been proposed. Resin sealing using epoxy resin has become the main method due to the balance of physical properties and other properties.

Recently, higher density and automation have been promoted in the mounting of components onto printed circuit boards.

In place of the conventional "insertion mounting method," in which lead pins are inserted into holes in the board, surface mounting methods, in which components are soldered to the surface of the board, are becoming popular. DIP (Dual Inline)
There is a shift from the FPP (Flat Plastic Package) type to the thin FPP (Flat Plastic Package) type, which is suitable for high-density packaging and surface mounting.

However, with the shift to surface mount methods, the soldering process, which used to be less of a problem, has become a major problem.

In other words, in the conventional bottle insertion mounting method, the soldering process only partially heats the leads, but in the surface mounting method, the entire package is immersed in a heating medium and heated, so it requires immersion in a solder bath, In soldering methods such as heating with saturated steam of inert gas (vapor phase method) and infrared reflow method, the entire package is heated to a high temperature of 210 to 270 ° C.
In packages sealed with conventional sealing resin, cracks sometimes occur in the resin part during soldering, resulting in lower reliability and the problem that the package cannot be used as a product.

It is said that the occurrence of cracks in the soldering process is due to moisture absorbed between the post-curing process and the mounting process explosively turning into water vapor and expanding when soldering is heated. A method is used in which the post-cured package is completely dried, stored in a sealed container, and shipped.

On the other hand, various improvements have been made to the sealing resin. For example, a method of blending a rubber component into the sealing resin to reduce internal stress (JP-A-58-219218, JP-A-59
96122), a method of reducing stress by blending silicone oil (Japanese Patent Laid-Open No. 62-254454).

Japanese Patent Publication No. 62-296449, Japanese Patent Publication No. 63-328
No. 07) and polyimide-based sealing materials that provide a high Tg have been proposed.

<Problems to be Solved by the Invention> However, the method of enclosing a dry package in a container in order to improve soldering heat resistance has the drawbacks of complicating the manufacturing process and handling of the product, and making the product extremely expensive. There is.

Further, the polyimide sealants that have been proposed so far have problems with moldability, fluidity, post-curing properties, etc., and are also insufficient in soldering heat resistance, so they have not yet been put into practical use.

Therefore, the object of the present invention is to obtain a resin composition for semiconductor encapsulation that solves the problem of cracks that occur during the soldering process and has improved moldability, fluidity, post-curing properties, and the like.

Therefore, an object of the present invention is to provide an epoxy resin-containing composition that is excellent in solder heat resistance, reliability, and moldability in a well-balanced manner, and to make it possible to realize a resin-sealed semiconductor device that can be surface mounted. be.

Means for Solving the Problems> As a result of intensive studies to achieve the above object, the present inventors have found that by using a modified silicone compound as a stress reducing agent and further mixing a bismaleimide compound. The inventors have discovered that an epoxy resin composition meeting the above objectives can be obtained, and have arrived at the present invention.

That is, the present invention comprises an epoxy resin (A), a curing agent (B)
, a modified silicone compound (C), fused silica (D>, and bismaleimide) as essential components, and the epoxy resin (A) has the following formula (I) ( Provided that R1 to R8 represent a hydrogen atom, a lower alkyl group of 01 to C4, or a halogen atom. It is.

Hereinafter, the configuration of the present invention will be explained in detail.

The epoxy resin (A>) in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule.

For example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bishydroxybiphenyl type epoxy resin, bisphenol A type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, halogenated epoxy resin and spiro ring-containing epoxy resins.

Depending on the application, two or more types of epoxy resins may be used in combination, but for semiconductor device encapsulation, cresol novolac type epoxy resins, bishydroxybiphenyl type epoxy resins, etc. with an epoxy equivalent of 50 are preferred in terms of heat resistance and moisture resistance.
It is preferable that the total epoxy resin contains 50% by weight or more of an epoxy resin having a molecular weight of 0 or less, particularly 300 or less.

In the present invention, the epoxy resin (A) has a skeleton represented by the following formula (I> (where R1-R8 represent a hydrogen atom, a C-C4 lower alkyl group, or a halogen atom). It is preferable to contain the epoxy resin (AN) as an essential component.By containing the epoxy resin (AN), the fluidity can be further improved.

Preferred specific examples of R1-R8 in the epoxy resin (A') represented by the above formula (1) include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a 5ec-butyl group, Examples include tert-butyl group, chlorine atom and bromine atom.

Preferred specific examples of the epoxy resin (AN in the present invention) include 4,4-bis(2,3-epoxypropoxy)biphenyl, 4,4'-bis(2,3-epoxypropoxy)-3'3-. 5.5-Tetramethylbiphenyl, 4゜4゛-bis(2,3-epoxypropoxy)3
．． 3-. 5.5-Tetramethyl-2-chlorobiphenyl, 4.4-bis(2,3-epoxypropoxy)-
3,1,5,5”-tetramethyl-2-bromobiphenyl, 4.4bis(2,3-epoxypropoxy)-3,
35,5'-tetraethylbiphenyl and 4,4'-
Bis(2,3-epoxy 10boxy)-3,1,5,5
--tetrabutylbiphenyl and the like.

In the present invention, the epoxy resin (A) is added to the epoxy resin (A).
When containing AI as an essential component, the epoxy resin (A>) may contain an epoxy resin other than the epoxy resin (Ai) together with the epoxy resin (A"). Other epoxy resins that can be used in combination For example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, novolac type epoxy resin represented by the following formula (I[) (where n is an integer of 0 or more) synthesized from bisphenol A, resorcin, etc. Examples include various novolac type epoxy resins, bisphenol A type epoxy resins, linear aliphatic epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins.

When using epoxy resin (A-), epoxy resin (
There is no particular restriction on the proportion of the epoxy resin (A') contained in A), and the epoxy resin (A') is included as an essential component.
The effect of the present invention is exhibited if N is contained, but in order to exhibit a more sufficient effect, the epoxy resin (A')
must be contained in the epoxy resin (A) in an amount of usually 50% by weight or more, preferably 70% by weight or more, particularly preferably 90% by weight or more.

In the present invention, the curing agent (B>) is an epoxy resin (A
It is not particularly limited as long as it can be cured by reacting with >.

For example, novolac resins such as phenol novolac and cresol novolac, bisphenol compounds such as tetrabromobisphenol A, acid anhydrides such as maleic anhydride, phthalic anhydride, and pyromellitic anhydride, and metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, etc. aromatic amines, etc. Among them, for semiconductor device encapsulation, heat resistance,
Phenol novolak and cresol novolak are preferably used from the viewpoint of preservability. Depending on the application, two or more types of curing agents may be used together.

In the present invention, the blending amount of the curing agent (B) is usually 2 to 15
Weight%.

Furthermore, the mixing ratio of the epoxy resin (A) and the curing agent (B) should be adjusted to (B) to (A) from the viewpoint of mechanical properties and moisture resistance.
The chemical equivalent ratio of is preferably in the range of 0.5 to 1.6, particularly 0.7 to 1.3. Further, in the present invention, a curing catalyst may be used to promote the curing reaction between the epoxy resin (A) and the curing agent (B). The curing catalyst is not particularly limited as long as it promotes the curing reaction. For example, 2-methylimidazole, 2,4-dimethylimidazole, 2
-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2
- Imidazoles such as heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 2-(dimethylaminomethyl)phenol, 2,4.6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo (5, 4,
O) Tertiary amines such as undecene-7, zirconium tetramethoxide, zirconium tetrapropoxide,
Organic metals such as tetrakis(acetylacetonato)zirconium and tri(acetylacetonato)aluminum, and triphenylphosphine, triethylphosphine, tributylphosphine, trimethylphosphine, tri(p-methylphenyl)phosphine, l.su(nonylphenyl) ) Examples include organic phosphines such as phosphine. These curing catalysts may be used in combination of two or more types depending on the application, and the amount added is 1 epoxy resin (A).
The range of 0.1 to 10 parts by weight per 00 parts by weight is preferable.

The modified silicone compound (C) in the present invention is a compound having an organopolysiloxane structure, and specific examples thereof include those having the structure of the following formula.

(R~R5 is hydrogen, one or more functional groups selected from a C1-C20 alkyl group, a phenyl group, and a vinyl group, X and Y are a C1-C20 alkyl group, a phenyl group,
A functional group having one or more groups and/or atoms selected from a vinyl group, a hydroxyl group, an amino group, an epoxy group, a carboxyl group, a mercapto group, a polyoxyalkylene group, an alkoxy group, and a fluorine atom, and Y may also be hydrogen. good. Further, m represents an integer of 1 or more, and n represents an integer of 0 or more. ) The amount of this modified silicone compound (C) added is usually 0.
01-5% by weight, preferably 0.1-3% by weight, especially 0
．． A range of 3 to 2% by weight is preferable in terms of soldering heat resistance and workability.

The fused silica (D) in the present invention has an average particle size of 2
The diameter is preferably 0 μm or less, and either crushed fused silica or spherical fused silica can be used alone or in combination.

In the present invention, the blending amount of fused silica is preferably in the range of 60 to 80% by weight, particularly 65 to 80% by weight; if it is less than 60%, the soldering heat resistance will be insufficient, and 80% by weight.
Exceeding this is not preferable because fluidity decreases and molding becomes difficult.

In the present invention, it is preferable to surface-treat the fused silica (D) with a coupling agent such as a silane coupling agent or a titanate coupling agent in advance in terms of moisture resistance and mechanical properties.

The bismaleimide compound (E) used in the present invention includes a compound obtained by the reaction of maleic anhydride and an aromatic diamine, or a compound obtained by modifying this with an amine or triazine, etc., and a compound having a bismaleimide group. If so, there are no particular limitations.

The blending amount of the bismaleimide compound (E) in the present invention is preferably in the range of 30 to 70% by weight, particularly 40 to 60% by weight based on the epoxy resin (A), and if it is less than 30% by weight, the soldering heat resistance is insufficient. Therefore, if it exceeds 70% by weight, fluidity decreases and molding becomes difficult, which is not preferable.

The epoxy resin composition of the present invention includes crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide,
Fillers such as asbestos and glass fibers, halogen compounds such as halogenated epoxy resins, flame retardants such as phosphorus compounds, flame retardant aids such as antimony trioxide, colorants such as carbon black and iron oxide, silicone oil, modified nitrile Rubber, elastomers such as modified polybutadiene rubber, coupling agents such as silane coupling agents and titanate coupling agents, long chain fatty acids, metal salts of long chain fatty acids, esters of long chain fatty acids, amides of long chain fatty acids, paraffins Mold release agents such as waxes and crosslinking agents such as organic peroxides can optionally be added.

The epoxy resin composition of the present invention is preferably melt-kneaded, and a known method can be used for the melt-kneading.

For example, Banbury mixer, kneader, roll,
A resin composition can be prepared using a screw or twin screw extruder, a co-kneader, etc., usually at a temperature of 50 to 150°C.

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

The numbers in the examples mean parts by weight.

Examples 1 to 4, Comparative Examples 1 to 2 Reagents were triblended using a mixer at the composition ratios shown in Tables 1 and 2. After heating and kneading this for 5 minutes using a mixing roll with a roll surface temperature of 90°C,
The mixture was cooled and pulverized to produce an epoxy resin composition.

Using this composition, 1
4. The simulated element was sealed by molding at 80°C for 2 minutes.
After obtaining the 4-pin QFP, it was post-cured at 180°C for 5 hours. After post-curing, the physical properties of each composition were measured using the following physical property measuring method.

Soldering heat resistance: 16 44-pin QFPs at 85℃,
After humidification treatment at 85% RH for 72 hours, the QFPs were immersed in a VPS bath at 215° C. for 90 seconds, and the percentage of QFPs without cracks was determined.

Reliability: 44 pins subjected to the solder heat resistance test described above.
Using QFP, humidification treatment was performed at 121° C. and 100% RH, and the time required for the pin failure rate to reach 50% was determined.

These results are shown in Table 2.

As is clear from the results in Table 2, the epoxy resin composition of the present invention has excellent moldability, soldering heat resistance, and reliability in a well-balanced manner.

<Effects of the Invention> As explained above, the epoxy resin composition of the present invention has an excellent balance of solder heat resistance, reliability, and moldability, making it possible to realize a resin-encapsulated semiconductor device that can be surface mounted. That is.

Patent application Daitoshi Co., Ltd.

Claims (2)

[Claims] (1) An epoxy resin composition comprising an epoxy resin (A), a curing agent (B), a modified silicone compound (C), fused silica (D), and a bismaleimide compound (E) as essential components. (2) Epoxy resin (A) has the following formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (However, R^1 to R^8 are hydrogen atoms, C_1 to C_4
represents a lower alkyl group or a halogen atom. ) Biphenyl epoxy resin having a skeleton represented by (
The epoxy resin composition according to claim 1, which contains A') as an essential component.