JPS59151436A - Resin sealing process of semiconductor device - Google Patents

Abstract

PURPOSE:To make the quality of the titled resin unchangeable reducing the cost thereof by a method wherein semiconductor elements are inserted into cavities provided in formed molds and firstly high purity fluid epoxy resin is poured into a runner communicating to the cavities and secondly this resin is forwarded by less fluid multipurpose epoxy resin to seal the semiconductor elements with the high purity resin. CONSTITUTION:Semiconductor elements 8 to be resin-sealed are inserted into cavities provided in formed molds 5 and resin is poured from an opening of a sprue 2 to runner 3. At this time, two kinds of resin, i.e. the first synthetic resin 8A, 8B and the second synthetic resin 9 are used. The first resin 8A, 8B comprises high purity epoxy containing excellent filler, hardener and stabilizer in terms of the electric characteristics and the mechanical strain while the second resin comprises cheap multipurpose epoxy resin not to be mixed with the former resin. Through these procedures, firstly the resin 8A, 8B and secondly the resin 9 are forwarded into the cavities by means of a plunger 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin sealing method for semiconductor devices such as transistors and semiconductor integrated circuits.

FIG. 1 shows a mold for resin-sealing semiconductor devices such as semiconductor integrated circuits. A spool 2 for injecting a sealing synthetic resin is provided in the center of the mold 1, and a runner 3 is formed in a direction perpendicular to the spool 2 as a passage for the molten synthetic resin. A plurality of runners 4 are formed in a radial shape (1) in order to equalize the flow of resin. A plurality of cavities 5 are formed at regular intervals on both sides of each runner 4 arranged in parallel, into which semiconductor devices are inserted and for molding synthetic resin for sealing into a prescribed shape.

In this mold 1, when comparing the volume occupied by the spool 2 and runners 3.4 with the volume occupied by each cavity 5, the volume of the spool 2 and runners 3.4 varies depending on the size of the molded product. Generally, the ratio is around 40% of the total. Figure 2 shows 1. , shows a cross section of the spool 2 and runner 3.4 portion of the synthetic resin molded product molded in this mold 1 along the line ■-■ in FIG.

As is clear from this figure, it can be seen that in the molded synthetic resin 6, the proportion of the synthetic resins 6A and 6B of the spool 2 and runner 3.4 is extremely large.

The spool 2 and runner 3 occupy a large volume in this way.
．． In No. 4, the molded and solidified synthetic resin is completely wasted, which greatly affects the price of the product. In particular, synthetic resins for resin encapsulation of semiconductor devices use high-purity epoxy resins to ensure the electrical characteristics, robustness, stability, etc. (2) of semiconductor devices, which increases the product price. It occupies a considerable proportion.

An object of the present invention is to provide a method for resin-sealing a semiconductor device, which can eliminate the waste of synthetic resin used for such resin-sealing and reduce the product price.

In the present invention, after inserting a semiconductor device to be resin-sealed into a cavity of a mold, a first synthetic resin is filled, and a second synthetic resin is filled from behind the first synthetic resin. The method is characterized in that the semiconductor device is sealed with a first synthetic resin.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 3 shows the same mold as shown in FIG. 1, and in the spool 2 and runner 3.4 of this mold 1, the volume of the portion 7 surrounded by the broken line and the entire volume of the mold 1 is calculated. .

Based on this calculation result, the synthetic resin for sealing is measured as shown in FIG. , 8B, the capacity of the second synthetic resin 9 used for the portion 7 is set. The first synthetic resins 8A and 8B are epoxy resins with high purity and high fluidity, which are used as fillers, hardening materials, stabilizers, etc., taking into consideration the electrical characteristics of semiconductor devices or the occurrence of mechanical distortion due to molding pressure. Use. On the other hand, the second synthetic resin 9 is a general-purpose epoxy resin with low fluidity, with a large amount of filler and a curing agent so as not to mix with the first synthetic resins 8A and 8B. etc. shall be used.

Next, as shown in FIG. 5, after inserting the semiconductor device 8 into the cavity 5 of the mold 1, the first synthetic resins 8A and 8B weighed as described above are placed behind the second synthetic resin. The resin 9 is heated and filled into the cavity 5 of the mold 1 sequentially from the direction of the arrow 11 using the plunger 10, and pressure molding is performed.

In this way, the first synthetic resins 8A, 8 with high purity
B goes to the cavity 5 for forming the desired semiconductor device 8, but at this time, in the second synthesis (4), the synthetic resin 9 is transferred by transmitting pressure from the rear of the first synthetic resins 8A and 8B. fulfill the role of As a result, in FIG. 3, the portion 7 surrounded by the broken line is occupied by the second synthetic resin 9, and the semiconductor device 8 in the cavity 5 is sealed with the high-purity first synthetic resins 8A and 8B as in the conventional case. It will be stopped.・ .

In the case of the above embodiment, the first and second synthetic resins 8A, 8B, and 9, which were weighed in relation to the mold, were shaped like disks, but as shown in FIG. The measured amounts of the second synthetic resins 8A, 8B, and 9 may be integrally formed. It goes without saying that the same effect can be obtained by using granular resins for the first and second synthetic resins instead of solid resins.

Furthermore, by color-coding the first and second synthetic resins, it may be possible to detect the mixture of the first and second synthetic resins during molding. The occurrence of defective products due to contamination between synthetic resins can be detected by detecting changes in the color of molded products.

(5) Furthermore, in the above embodiment, resin encapsulation of a semiconductor integrated circuit was explained, but such a resin encapsulation method can be similarly applied to transistors and other electronic components, and similar effects can be obtained. You can expect it.

As explained above, according to the present invention, the first synthetic resin for sealing the semiconductor device is of high purity as in the conventional method, and the first synthetic resin is transferred to the molding cavity. By using an inexpensive, low-purity synthetic resin for the second synthetic resin, we can maintain a constant product quality, save on high-purity synthetic resin, eliminate its waste, and reduce the manufacturing cost of the product. It is possible to reduce the

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the mold, Figure 2 is n-n of Figure 1.
FIG. 3 is a cross-sectional view of the synthetic resin molded product taken along the line; FIG.
FIG. 5 is an explanatory diagram showing a resin sealing method for a semiconductor device of the present invention, and FIG. 6 is a perspective view showing the structure of a synthetic resin for sealing. (6) 1... Molding mold, 2... Spool, 3.4... Runner, 5... Cavity, 8... Semiconductor device, 8A,
8B...first synthetic resin, 9...second synthetic resin. (7) Figure 1 Figure 2 b b Figure 3 Figure 4 Figure 5 Figure 6, 4+1- 5j-3235

Claims (1)

[Claims] After inserting the semiconductor device to be resin-sealed into the cavity of the mold, a first synthetic resin is filled, and a second synthetic resin is filled from behind the first synthetic resin, and the semiconductor device is filled with a second synthetic resin. 1. A resin sealing method for a semiconductor device, characterized in that the resin sealing method is performed using a synthetic resin according to item 1.