JPH09267329A - Epoxy resin composition tablet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide epoxy resin composition tablet excellent in moldability and reliability wherein a cavity is hardly generated in the inside or outside of a resin seal type semiconductor device. SOLUTION: This epoxy resin composition tablet has at least 90% packing ratio and is obtained by molding an epoxy resin composition powder. The tablet is that in which the maximum particle size of the powder is at most 2mm. The tablet comprises the epoxy resin composition containing a biphenyl type epoxy resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition tablet having excellent moldability and reliability.

[0002]

2. Description of the Related Art Generally, a resin-encapsulated semiconductor device is manufactured by charging a doublet-shaped encapsulating resin into a heated mold pot.
The element and the frame are manufactured by sealing by a transfer molding method in which the element and the frame are transferred and injected into a preset cavity portion.

[0003]

However, since the tablet-like sealing resin is usually manufactured by compression using a mold of a crushed resin composition, it necessarily contains a certain amount of gas (air) component. I'm out. When the resin melts and flows into the cavity, this gas component enters the cavity at the same time, and causes voids generated inside or outside the package. Such internal / external cavities are not only a problem in appearance, but also greatly affect the reliability of the semiconductor device such as humidity resistance and thermal shock resistance.

With the recent increase in size and thickness of semiconductor packages, the problem of nests has become more serious. The encapsulating resin using a biphenyl-type epoxy resin, which has been recently studied as a highly reliable encapsulating resin, has a drawback that cavities are particularly likely to occur.

The present invention has been made in view of the above circumstances, and provides an epoxy resin composition tablet excellent in moldability and reliability, in which cavities are less likely to occur inside or outside a resin-sealed semiconductor device. Is what you are trying to do.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that controlling the particle size of the powder of an epoxy resin composition drastically reduces the generation of cavities. The present invention has been completed and the present invention has been completed.

That is, the present invention is an epoxy resin composition tablet having a filling rate of 90% or more obtained by preforming a powdered epoxy resin composition, wherein the maximum particle size of the powder is
It is an epoxy resin composition tablet characterized by being 2 mm or less.

Hereinafter, the present invention will be described in detail.

The epoxy resin composition used in the present invention may be any one that can be used for tablets, and contains an epoxy resin, a phenol resin type curing agent, a curing accelerator, a filler and the like. Next, each component of the epoxy resin composition will be described.

The epoxy resin is not particularly limited as long as it has two epoxy groups in one molecule. Specific examples of the epoxy resin include, for example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol A glycidyl ether, and tri (hydroxyphenyl) alkane. Examples of the epoxy resin, tetra (hydroxyphenyl) alkane epoxy resin, bishydroxybiphenyl epoxy resin, various brominated epoxy resins, and the like can be used alone or in combination of two or more.

In the present invention, it is more preferable to use a biphenyl type epoxy resin having the structure of Chemical formula 1 in all or part of the epoxy resin. This is because inner and outer cavities are likely to occur when this epoxy resin is used.

[0012]

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Any epoxy resin curing agent may be used as long as it has a phenolic hydroxyl group in the molecule, and those obtained by condensation of phenol or alkylphenols with hydroxybenzaldehyde can be used. For example, tris (hydroxyphenyl) methane, tris (hydroxymethylphenyl) methane, tris (hydroxyphenyl) propane, tris (hydroxyphenyl) methylmethane, various novolac type phenol resins, phenol aralkyl resins, terpene phenol resins, dicyclopentadiene. Examples thereof include phenol resins and naphthol resins, which can be used alone or in combination of two or more kinds. To ensure the reliability of semiconductor devices, these resins contain 1% of free phenols in the resin.
It is desirable that:

The mixing ratio of the epoxy resin and the phenol resin curing agent is such that the ratio of the number of phenolic hydroxyl groups of the phenol resin as a curing agent to the number of epoxy groups of the epoxy resin (number of phenolic hydroxyl groups / number of epoxy groups) is in the range of 0.1 to 2.5. It is desirable to mix them as follows. If this ratio is less than 0.1, the curing reaction is difficult to occur sufficiently, and if it exceeds 2.5, the properties of the cured product, especially the moisture resistance, are poor, and this is not preferred.

As the curing accelerator, those which accelerate the curing reaction of the resin and those which can be used as the ordinary curing accelerator for the sealing material can be widely used. Specific examples of the curing accelerator include 2-methylimidazole, imidazoles such as 2-heptadecylimidazole, diazabicycloalkenes such as diazabicycloundecene and salts thereof, organic phosphines such as triphenylphosphine,
Other examples include organic metal compounds.

The inorganic filler is not particularly limited as long as it is generally used as a sealing material, and can be widely used. As a specific inorganic filler, for example, fused silica, crystalline silica, alumina,
Examples thereof include silicon nitride and aluminum nitride, which can be used alone or in combination of two or more.

The epoxy resin composition used in the present invention contains the above-mentioned epoxy resin, curing agent, curing accelerator, inorganic filler and the like. Flame retardant aids such as antimony oxide, natural waxes, synthetic waxes, linear fatty acids and metal salts thereof, mold release agents such as acid amides, esters and baffins, pigments such as carbon black and titanium dioxide, silicone oils. , Silicone rubber, various plastic powders, various engineering plastic powders, ABS resin and MBS resin powders, and other stress-reducing agents can be added as appropriate.

Epoxy resin is prepared by blending the above-mentioned components, thoroughly mixing them with a mixer such as a Henschel mixer, melt-processing with a hot roll or melt-mixing with a biaxial extruder, and then cooling and pulverizing. The composition can be manufactured. Maximum particle size of crushed powder is 2
mm or less. More preferably, the maximum particle size is 2 mm or less, and particles having a maximum particle size of 1 mm or less account for 60% by weight or less of the whole particles. Maximum particle size is 2m
If it exceeds m, the air remaining in the tablet is a cause, and a nest is generated in the semiconductor package, which is not preferable. It is considered that by using a large number of particles having a small particle size, the lump of air remaining in the tablet is divided into small pieces, and even if they enter the cavity, they are crushed by the pressure during molding. In this case, the filling rate of the tablet is 90% or more, preferably 95% or more. If the filling rate is less than 90%, for example, even if the pressure is reduced, it is not possible to obtain a sufficient effect on the cavities, which is not preferable.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In the following Examples and Comparative Examples, “parts” means “parts by weight”.

Example 1 Biphenyl type epoxy resin (epoxy equivalent 193) 4.9
Parts, bisphenol A type brominated epoxy resin (epoxy equivalent 460) 2.0 parts, phenol novolac resin (phenol hydroxyl equivalent 104) 3.1 parts, triphenylphosphine
0.15 parts, carnauba wax 0.3 parts, spherical fused silica (average particle size 20 μm) 87.0 parts, carbon black 0.3 parts,
2.0 parts of antimony trioxide and 0.4 parts of epoxy silane coupling agent are mixed and mixed in a Henschel mixer, kneaded with a heating roll at 60 to 130 ° C, cooled and pulverized to prepare an epoxy resin composition. did.

Next, the particle size of the crushed epoxy resin composition is adjusted to a maximum particle size of 2 mm,
A cylindrical doublet having a packing density of 95% and a diameter of 30 mm was molded by a compression press to manufacture an epoxy resin composition tablet.

Example 2 Epoxy was treated in the same manner as in Example 1 except that 60% of particle size 2 mm and 40% of particle size 1 mm were used instead of the particle size in the epoxy resin composition of Example 1. A resin composition tablet was produced.

Example 3 Epoxy was treated in the same manner as in Example 1 except that 40% of particle size was 40% and 1 mm of particle size was 60% instead of the particle size in the epoxy resin composition of Example 1. A resin composition tablet was produced.

Example 4 An epoxy resin composition tablet was produced in the same manner as in Example 1 except that 100% of particle size 1 mm was used instead of the particle size in the epoxy resin composition of Example 1.

Comparative Example 1 An epoxy resin composition tablet was prepared in the same manner as in Example 1, except that 100% of the epoxy resin composition having a particle size of 3 mm was used instead of the particle size of the epoxy resin composition of Example 1. Manufactured.

Comparative Example 2 An epoxy resin composition tablet was prepared by the same procedure as in Example 1 except that 100% of the epoxy resin composition having a particle diameter of 3 mm was used instead of the particle diameter of the epoxy resin composition of Example 1. did.

Comparative Example 3 Epoxy was treated in the same manner as in Example 1 except that 60% of particle size 3 mm and 40% of particle size 1 mm were used instead of the particle size in the epoxy resin composition of Example 1. A resin composition tablet was produced.

Using the epoxy resin composition tablets prepared in Examples 1 to 4 and Comparative Examples 1 to 3, transfer injection was performed into a mold heated to 180 ° C., and a body size of 32 mm equipped with a 15 mm square dummy chip was mounted. Corner (thickness 3.5m
m) QFP was molded. The appearance nests and inner nests of these packages were observed, and the results are shown in Table 1. In all of the present invention, the generation of nests was small, and the effect of the present invention could be confirmed.

[0029]

[Table 1] * 1: The number of nests per 1 package (PKG) was measured. * 2: Polished little by little and measured the number of cavities per package (PKG) of φ 0.3 or more.

[0030]

As is clear from the above description and Table 1, the epoxy resin tablet of the present invention is less likely to have cavities inside or outside during resin encapsulation of a semiconductor device,
It has excellent moldability and reliability.

Claims (2)

[Claims] 1. An epoxy resin composition tablet having a filling rate of 90% or more obtained by preforming a powdered epoxy resin composition, wherein the maximum particle size of the powder is 2 mm or less. Epoxy resin composition tablet. 2. The epoxy resin composition tablet according to claim 1, wherein the epoxy resin composition is an epoxy resin composition containing a biphenyl type epoxy resin.