JPS609133A - Molding mold for semiconductor resin sealing - Google Patents

Abstract

PURPOSE:To enable to quickly flow out the resin located in the center part of the resin supply part which becomes hard lastly by a method wherein a conical- shaped or semispherical guide groove, which is interconnected to a resin supply part, is provided on a bottom force or a top force. CONSTITUTION:A plunger 5 is pressed upward in the state wherein the internal resin 71 which becomes hard lastly is located in the center part of a resin supply part and the external resin 72 which becomes hard relatively earlier is located in the circumference of the internal resin 71, and the internal resin 71 is flown out to a cavity preferentially through a gate 6 so that the resin 71 will not be left in the final stage of sealing at the resin supply part 3 and the guide groove 2. A conical-shaped guide groove 2 is provided on the parting surface of a top force in such a manner that it will be interconnected to the resin supply part 3. As a result, the internal resin 71 can be preferentially flown out to the cavity passing through the gate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a semiconductor resin encapsulation mold, and particularly to a semiconductor resin encapsulation mold in which there are a plurality of resin transfer plungers.

[Technical background of the invention and its problems]

As is well known, a mold for semiconductor resin encapsulation is used to encapsulate a semiconductor chip mounted on a lead frame with resin.

Conventionally, the mainstream of such molds has been one having a runner structure with a single plunger (hereinafter referred to as SPS). However, SPS has the disadvantage that the cycle time is long and the resin is not uniformly distributed to the tip of the runner.

For this reason, a structure having a plurality of grungers without a runner (hereinafter referred to as MPS) has recently been implemented. Below, the above 8 P S , l! :M
A comparison will be made of the performance when a semiconductor chip of a lead frame, for example, a 42-pin DIP type IC, is resin-sealed using PS.

Table MPS has the advantage that the cycle time can be shortened compared to SPS as shown in the table above, and that the resin can evenly spread to each cavity. However, M
PS has the disadvantage that the output per hour is lower than that of SPS.

By the way, in order to solve this problem of production volume, it is only necessary to further shorten the cycle time. However, thermosetting resins are generally used for semiconductor resin encapsulation. Therefore, after the resin is softened by heating, it is cured by a chemical change, but the way the resin is heated is not uniform, resulting in a difference in curing time. That is,
In MPS, the resin in the pot section (resin supply section) where resin is set, especially the central part of the pot section, is the slowest. As a result, when the mold is opened after the semiconductor chip is sealed with resin, uncured resin adheres to the mold. Therefore, it is necessary to open the mold after the resin in the slowest hardening area has hardened.
It becomes difficult to reduce the cycle time below the value shown in the table above (3 minutes).

[Purpose of the invention]

The original [! J] was made in view of the above circumstances, and the purpose is to provide a semiconductor resin encapsulation mold that can prevent differences in curing time depending on the resin installation location, shorten cycle time, and thereby improve productivity. That is.

[Summary of the invention]

The present invention provides a resin supply section provided on one side of the upper mold or the lower mold, a plunger provided on the resin supply section, and a resin supply section provided on the lower mold or the stopper mold. By having a conical or hemispherical guide groove provided so as to communicate with each other, when the resin set in the resin supply section flows through the dirt into the cavity where the semiconductor chip is set, the resin hardens after molding. The main idea is to quickly drain out the resin in the central part of the resin supply section, where it is thought to be the most delayed, so that it does not remain in the resin supply section, thereby improving productivity. ] Hereinafter, one embodiment of the present invention will be described with reference to FIG.

1 in the figure is the upper mold. A conical guide groove 2 is provided on the 74-ring surface of the upper mold 1 so as to communicate with a resin supply section described later.

Furthermore, a lower mold 4 having a resin supply section 3 is provided below the upper mold 1 . The resin supply section 3 of the lower mold 4 is provided with a vertically movable gland shear 5 that pushes out the resin. A dart 6 is provided between the upper mold 1 and the lower mold 4, and a cavity (not shown) having a shape capable of accommodating a semiconductor chip mounted on a lead frame is provided.

Next, the case where the resin flows out into the cavity using the above-mentioned mold will be explained using FIGS. 2(a) to 2(d). 1. As shown in No. 21ffi(a), the internal resin 7. which hardens the slowest is placed in the central portion of the resin supply section 3. has
From the state where the outer peripheral resin 72, which hardens relatively quickly, is provided around the inner resin 71 of the bracket, the glasher 5 is pressed upward to bring it into the state shown in FIG. 2(b). At this time, the outer peripheral resin 7
The internal resin 7I is allowed to stay on the side and flow out preferentially through the dart 6 into the cavity. Below, Fig. 2(c), (
7. Internal resin as shown in d). preferentially flows through the dart 6 into the cavity, causing the slow-curing internal resin 7. Make sure that the resin supply portion 3 and the resin remain in the id groove 2 until the end.

According to the mold for semiconductor resin encapsulation of the present invention, the conical guide groove 2 is provided in the parting surface of the upper mold so as to communicate with the resin supply section 3. Therefore, during molding, the slow-curing internal resin 7. can be preferentially flowed through R-Toro to Kyagiti.

Therefore, the guide groove 2 has an outer peripheral resin 7. which hardens relatively quickly. can remain, and the curing speed of the resin at each part of the mold after molding can be kept almost constant. As a result, cycle time can be shortened compared to conventional methods and productivity can be improved. In fact, the cycle time with the mold of the invention is, for example, 42 bins DIP
mIC.

It took 1.5 minutes to take 24 pieces, and the production amount per hour was 960 pieces. This confirms that the mold of the present invention has productivity approximately 1.3 times higher than that of conventional SPS, and is significantly superior.

2. In the above embodiment, the case where a conical groove is provided on the parting surface of the upper mold is described, but the present invention is not limited to this. For example, even when a hemispherical guide groove 8 is provided on the A-ting surface of the upper mold as shown in FIG. 3, the same external effects as in the above embodiment can be expected.

〔Effect of the invention〕

As detailed above, according to the invention, it is possible to provide a highly reliable semiconductor resin restraining mold that can improve productivity.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a semiconductor resin encapsulation mold according to an embodiment of the present invention, and FIG. 2 (a) to (d) illustrate the state of resin flow in the total sugar shown in FIG. 1. FIG. 3 is a cross-sectional view of a semiconductor resin encapsulation mold showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Upper mold, 2, 8... Guide groove, 3... Resin supply part, 4... Lower mold, 5... Silanger, 6...
...Dart, 7. ...Internal resin, 7. ...Outer peripheral resin 3, Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Do b Figure 2 (c) (d) Figure 3 Fi

Claims (1)

[Claims] In semiconductor resin encapsulation molds used for resin encapsulation of semiconductor chips mounted on lead frames,
an upper mold, a lower mold, a resin supply section provided in either the upper mold or the lower mold, a plunger provided in the resin supply section, and the lower mold or the upper mold. 1. A mold for resin encapsulating a semiconductor, comprising: a conical or hemispherical guide groove provided to communicate with the resin supply section.