JPS62223246A - Highly thermally conductive resin composition for use in sealing semiconductor - Google Patents

Abstract

PURPOSE:To improve the thermal conductivity of the compsn. and the working stability, life, moisture resistance, etc. of sealed semiconductors, by using a filler mainly composed of boron nitride as a filler to be blended with a resin compsn. for use in sealing semiconductors. CONSTITUTION:A filler powder which is mainly composed of boron nitride and pref. spherical is prepd. The filler powder is mixed with a base resin (e.g., an epoxy resin or a silicone resin) to obtain the desired highly thermally conductive resin compsn. for use in sealing semiconductors. The resulting resin compsn. is particularly suitable for use as an epoxy mold resin compsn. for low-pressure transfer molding.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a highly thermally conductive resin composition for semiconductor encapsulation.

More specifically, the present invention relates to a highly thermally conductive resin composition for encapsulating a semiconductor, which is suitably used as an epoxy mold resin composition for low-pressure transfer molding.

[Conventional technology and its problems] In recent years, the needs for higher integration, higher speed operation, and higher current processing of semiconductor devices such as highly integrated memories such as LSI and VLSI, power semiconductors, ECLnAH, and video RAM have been met. , the production of semiconductor devices that consume high power during operation is increasing. However, if these elements are sealed with resin from the viewpoint of cost benefits, the semiconductor elements consume high power and generate a large amount of heat, so if heat is not dissipated sufficiently, the temperature of the element will rise. As a result, basic performance such as operational stability and life characteristics of semiconductor device junctions and gold-aluminum alloy wire bond joints deteriorates, causing major problems in product reliability. For this reason, conventional measures have been taken to install heat sinks and heat sinks to dissipate the heat generated from semiconductor elements, but the heat is not dissipated sufficiently with the above measures, and it is necessary to install heat sinks and heat sinks. This complicates the structure of the product, leading to new problems such as deterioration of moisture resistance, which has the disadvantage of reducing product reliability.

Therefore, there is a need for a resin composition for semiconductor encapsulation with high thermal conductivity that can encapsulate a semiconductor element that generates a large amount of heat with a resin even when a heat sink or a heat sink is not installed.

Conventional resin compositions for semiconductor encapsulation, especially epoxy mold resin compositions such as epoxy mold resin compositions for low-pressure transfer molding, are filled with fillers for the purpose of improving heat resistance, mechanical strength, heat shrinkage rate, cost, etc. Amorphous quartz powder is mainly blended as a material, but the quartz powder,
Although it is recognized that the quartz powder contributes to improving the thermal conductivity of the molding resin composition, it is not very effective in improving the thermal conductivity of the molding resin composition itself because the thermal conductivity of the quartz powder itself is not so high. For example, in a typical epoxy mold resin composition for semiconductor encapsulation, the thermal conductivity of the cured product after thermosetting is lX10-4 to 5x1O-4Ca.
The resin base material has a thermal conductivity of 0.006 to 0.008Ca1/cm-8eC・℃, which is about 1/cI+l−5eC・℃.
Approximately 50% by volume of amorphous quartz powder in the composition
The thermal conductivity of the cured product of the conventional low-pressure transfer molding epoxy mold resin composition is approximately 0.5x.
10-3~1. Ox 10-'ca1/cm-se
The thermal conductivity was about Ce'c and the thermal conductivity was not sufficiently improved.

Therefore, in order to further increase the thermal conductivity of the molding resin composition, molding resin compositions have been developed that contain crystalline quartz powder and magnesia powder, which have high thermal conductivity among quartz powders, as fillers. No molding resin composition with satisfactory thermal conductivity has been found so far. Furthermore, since magnesia powder itself is highly hygroscopic, it has a major problem in that the moisture resistance reliability, which is an important performance of resin-sealed semiconductor devices, is significantly inferior.

As a result of extensive research to solve the above-mentioned problems, the present inventors found that when boron nitride powder is blended as a filler, which is the main component of a resin composition for semiconductor encapsulation, quartz The heat dissipation properties of semiconductor elements encapsulated with this resin composition are greatly improved compared to cases where powder or magnesia powder is blended, and the reliability such as moisture resistance of semiconductor elements after resin encapsulation is also improved. It was discovered that no problem occurred, and the present invention was completed.

That is, the present invention improves the thermal conductivity of a semiconductor encapsulating resin composition such as a molding resin composition for low-pressure transfer molding, thereby increasing the heat dissipation of a semiconductor element encapsulated with the resin composition. The purpose is to improve product performance such as operational stability and life characteristics.

[Means for Solving the Problems] The present invention relates to a highly thermally conductive resin composition for semiconductor encapsulation characterized by comprising a filler containing boron nitride as a main component and a base material.

[Function] The highly thermally conductive resin composition for semiconductor encapsulation of the present invention contains boron nitride powder as a main filler component of the resin composition. The heat dissipation properties of semiconductor devices that consume high power are significantly improved, and the heat dissipation properties are significantly improved compared to the above-mentioned quartz powder and magnesia powder. It also has excellent characteristics and reliability.

[Example] In the present invention, boron nitride (hereinafter referred to as BN) powder is used as the main component of the filler. B
The shape of the N powder may be crushed, spherical, or a mixture thereof, but its particle size and particle size distribution are similar to conventional quartz powder, with an average particle size of about 10 to 20 ρ, and a maximum particle size of about 10 to 20 ρ. Preferably, the diameter is less than about 200ρ. If the maximum grain size is larger than about 200 uIn, the opening of the gate, which is the entrance to the mold, is about 200 to 300 mm, which may cause it to become clogged. The ratio of the BN powder in the filler is preferably 80% (volume %, the same applies hereinafter) or more,
More preferably, it is 95% or more.

As the resin base material, which is the other main component constituting the highly thermally conductive resin composition for semiconductor encapsulation of the present invention, the epoxy resin or silicone resin base material used so far can be used as is.

The filling rate of the filler containing the BN powder as a main component with respect to the epoxy resin or silicone base material is preferably within the range of 30 to 80%. In particular, when the shape of the filler is spherical, mold wear and fluidity during resin sealing are greatly improved, which is particularly preferable in terms of preventing mold wear and improving moldability.

Hereinafter, the effects of the present invention will be explained in more detail using Examples and Comparative Examples, but the present invention is not limited to the detailed explanations given so far or the Examples below.
In particular, it is obvious that thermoplastic resins such as PPS (polyphenylene sulfide) can also be used as the resin base material.

Example 1 and Comparative Example 1 Comparative Example 1 is a resin composition for semiconductor encapsulation of conventional specifications in which crystalline quartz powder is blended as a filler into an epoxy mold resin base material for low-pressure transfer molding using a cresol novolac type epoxy resin. , as well as BN as filler
The highly thermally conductive resin composition for semiconductor encapsulation of the present invention containing the powder was prepared as Example 1, and the resin composition for semiconductor encapsulation was vA$
I did 1. The average particle size of each filler is about 15 to 20 particles, and the filling rate is about 50%.

Using each of the obtained resin compositions, an evaluation diode chip (1.7n+n+x 1.7 mm) for measuring thermal resistance was molded, and the thermal resistance of the molded package was measured according to a predetermined measuring method. The results are shown in Table 1.

Table 1 (Note) θ: Diode junction and -A Thermal resistance between package and surrounding environment , and the smaller the value of θ, the -A The resin composition has good heat dissipation properties. and

Example 2 and Comparative Example 2 Using the resin compositions obtained in Example 1 and Comparative Example 1, 64
A mold package of a bit video RAM was produced in a size 4×4, and a mold package was prepared as Example 2 and Comparative Example 2. These 175℃
When comparing the high temperature operation life time (time until the defective rate reaches 50%) in , it was found that using the resin composition obtained in Example 1 of the present invention was better than using the resin composition obtained in Comparative Example 1. It had a lifespan more than twice as long as that of the previous model, and there were no problems with various reliability characteristics such as moisture resistance.

[Effect of the invention 1] From the above Examples and Comparative Examples, the highly thermally conductive resin composition for semiconductor encapsulation of the present invention has good heat dissipation properties, excellent operational stability and life characteristics of semiconductor devices, and reliable moisture resistance. It can be seen that it has excellent properties in terms of properties and moldability.

Claims (2)

[Claims] (1) A highly thermally conductive resin composition for semiconductor encapsulation, comprising a filler containing boron nitride as a main component and a base material. (2) The highly thermally conductive resin composition for semiconductor encapsulation according to claim (1), wherein the filler containing boron nitride as a main component is spherical.