JPH066619B2 - Epoxy resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for encapsulation. More specifically, the present invention relates to an epoxy resin composition for encapsulating a semiconductor device or the like which has low stress and high Tg and high strength.

(Prior Art) Conventionally, as a sealing method for electric / electronic parts such as diodes, transistors, integrated circuits, and semiconductor devices, resin sealing methods such as epoxy resin or silicon resin, glass, metal, ceramics, etc. The hermetic sealing method using has been adopted, but in recent years,
The mainstream is resin encapsulation by low-pressure transfer molding using epoxy resin, which has advantages in terms of mass production and cost as well as improved reliability.

In this encapsulation method using an epoxy resin, a molding material composed of a composition containing an orthocresol novolac type epoxy resin as a resin component and a phenol novolac type resin as a curing agent component is most commonly used.

(Problems to be Solved by the Invention) However, due to the thinning of the mold resin accompanying the high density and high integration of electronic parts such as IC, LSI, and VLSI and semiconductor devices, and the flattening of devices, the conventional epoxy The resin composition cannot always satisfy the requirement.

For example, due to the manifestation of the stress caused by the difference in the thermal expansion coefficient between the IC substrate, the lead frame and the cured molded product due to the temperature change, the slide of the IC aluminum wiring, the breaking of the bonding gold wire, the IC interface and the cured cured product. And peeling of the cured product and cracks of the cured cured product have occurred.

As a method for coping with these problems, lowering the stress of the cured product of the encapsulating resin can be mentioned, but simply lowering the elastic modulus of the cured product simultaneously lowers the glass transition point (Tg), Will cause stress. At the same time, the mechanical strength must be reduced, and as a means for satisfying the contradictory characteristic requirements of lowering the elastic modulus (lowering stress) and higher Tg, the epoxy resin cured product matrix is A so-called resin hybrid, in which rubber-like low-elasticity fine particles are uniformly dispersed, has been proposed and has been widely adopted.

For example, specifically, it is a method of adding a silicone rubber powder and an organopolysiloxane oil having a functional group capable of reacting with an epoxy resin at the time of kneading the resin and the filler.

However, this method has a problem in uniform dispersibility of particles from the viewpoint of compatibility, and naturally the amount added is limited, so that a desired high Tg and low elastic modulus cured product has not been obtained. . Further, in this case, the so-called domain particle size formed by the organopolysiloxane also becomes very large, which causes separation and the like when used as a sealing body, which causes various problems as a sealing IC.

The present invention has been made in view of the above circumstances, and is a new encapsulation capable of improving the defects of the conventional encapsulating epoxy resin, improving the low stress property, and increasing the Tg and the strength. The purpose is to provide an epoxy resin composition for stopping.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention was obtained by radical-adding polymerization of vinyl silicone with a peroxide to an epoxy resin to which (A) an amino silicone was added. There is provided an epoxy resin composition for encapsulation, which comprises an epoxy resin, (B) a curing agent, (C) a curing accelerator, and (D) an inorganic filler.

As the epoxy resin to which the aminosilicone is added for the component (A) in this composition, an appropriate one such as a conventionally known orthocresol novolac type epoxy resin, bisphenol A type epoxy resin, or bisphenol F type epoxy resin is used. And more preferably an orthocresol novolac type epoxy resin can be used.

Amino silicone added to these epoxy resins is
It is shown as an organopolysiloxane or the like modified by introducing an amino group into the molecule, and the amino group equivalent can be in a wide range of, for example, about 300 to 3,000.

When the epoxy resin added with this aminosisilicone is used alone, the strength of the encapsulating resin is largely reduced, and if the strength is to be maintained, the desired low stress property cannot be obtained.

On the other hand, in the case where the vinyl silicone used in the component (A) of the present invention is only radically added to the epoxy resin, the particle size of the silicone domain is very large from the viewpoint of compatibility, and the effect of reducing stress is reduced. Moreover, since the adhesion to the matrix is poor, the mechanical strength is reduced. It is possible to reduce the domain diameter and improve the adhesion to the matrix by using various compatibilizers such as polyether-modified silicone. In this case, in this case, the chemical property between the domain and the matrix is reduced. Since it does not have a mechanical bond, there is a limit to the effect of preventing reduction in mechanical strength.

Further, a compatibilizing agent such as polyether silicone has high hygroscopicity, which is disadvantageous from the viewpoint of resistance to moisture absorption cracking.

However, the above problems are solved by the component (A) of the present invention. That is, the aminosilicone-added epoxy resin has the property as a compatibilizer, the domain diameter of the vinylsilicone radical addition polymer is reduced, and it occurs with the chemical bond between the domain and the matrix, that is, with the addition of vinyl groups to each other. Due to the bond formed by the reaction between the methyl group and the like of the aminosilicone and the vinyl group, the reduction in mechanical strength and the reduction in stress can be achieved.
Entangled as a crosslinked structure, it is considered to have a unique effect. The vinyl silicone in this case is also made of organopolysiloxane having a vinyl group.

From these viewpoints, the weight ratio of the component (A) as a silicone component is usually preferably about 1/4 to 2/1 of aminosilicone / vinylsilicone. If it is less than 1/4, the compatibilizing effect becomes small and the domain particle size becomes large. On the other hand, if it is larger than 2/1, the effect of aminosilicone becomes large, resulting in a large decrease in strength.

The type of peroxide used in radical addition polymerization of vinyl silicone is not particularly limited, but for example, the following formula (Wherein R ₁ and R ₂ each represent a methyl group or a phenyl group) can be preferably used.

A phenol resin is preferably used as the curing agent of the component (B), and a phenol novolac resin is shown as a specific example. There is no particular limitation on the type of the component (C) curing accelerator to be blended therein, and one or more effect accelerators such as phosphorus-based, tertiary amine-based, or imidazole-based effect accelerators can be used. .

Also for the inorganic filler of the component (D), silica, alumina, talc, aluminum hydroxide, magnesia and the like can be appropriately used. Silica is particularly preferable.

Of course, the resin composition of the present invention has the above (A)
It goes without saying that, in addition to (B), (C) and (D), suitable additives such as flame retardants and release agents may be added.

(Operation) In the epoxy resin composition of the present invention, by using an epoxy resin by vinyl silicone addition polymerization to an amino silicone addition epoxy resin, various properties as a sealing material are maintained, stress is reduced, and high Tg is achieved. And high strength can be realized.

(Example) Hereinafter, an Example is shown and the epoxy resin composition for closure of this invention is demonstrated still in detail.

Examples 1 to 3 (Comparative Examples 1 and 2) The following types of epoxy resins were prepared as the epoxy resin to be added to the composition.

Resin (a): 130 parts of a cresol novolac type epoxy resin having an epoxy equivalent of 195 and 7 parts of a terminal aminosilicone (a-1) having an amino group equivalent of 2400 at N at a temperature of 140 ° C.
_The mixture was heated and reacted in ₂ atmospheres for 3 hours.

Next, an equivalent weight 15,000 terminal vinyl-modified silicone (a-
2) 23 parts and 0.2 part of t-butylcumyl peroxide were added dropwise, and the mixture was heated and reacted at a temperature of 140 ° C. for 1 hour under N ₂ atmosphere to obtain a predetermined resin.

Resin (b): Aminosilicone (a
-1) 12 parts and 18 parts of inylsilico (a-2) were reacted to obtain a predetermined resin.

Resin (c): The resin (a) was reacted with 20 parts of amino silicone (a-1) and 10 parts of vinyl silicone (a-2) to obtain a predetermined resin.

Resin (d): 30 parts of amino silicone (a-1) in resin (a) and vinyl silicone (a-)
The reaction was carried out without adding 2) to obtain a predetermined resin.

Resin (e): In the resin (a), vinyl silicone (a-
30 parts of 2) was reacted to obtain a predetermined resin.

A resin composition of the present invention was prepared using the resins (a) to (c) described above, and a resin composition for comparison was prepared using the resins (d) to (e). The blending ratio is shown in Table 1.

In addition, the flexural modulus, flexural strength, Tg (glass transition point), and coefficient of linear expansion of each resin composition were evaluated. The results are also shown in Table 1.

It can be seen that Examples 1 to 6 of the present invention have lower stress properties and higher Tg and strength than the Comparative Examples.

(Effects of the Invention) As described in detail above, according to the present invention, a resin encapsulating material having a high Tg and a high strength, which achieves low stress and does not impair other characteristics, is provided.

Claims (2)

[Claims] 1. An epoxy resin in which vinyl silicone is radical-addition-polymerized with the following components (A) aminosilicone-added epoxy resin, (B) curing agent (C) curing accelerator (D) inorganic An epoxy resin composition for encapsulation, which comprises a filler. 2. The epoxy resin composition according to claim 1, wherein the weight ratio of the aminosilicone to the vinylsilicone in the epoxy resin (A) is 1/4 to 2/1.