JPS5843900B2 - Sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device sealing device, and particularly to a transfer resin molding device.

As is well known, in the manufacture of semiconductor devices and semiconductor integrated circuit devices, there is a step of molding main parts such as semiconductor elements, wires, and inner ends of leads with resin.

By the way, when performing this molding by transfer molding, the resin is applied to the lead frame 1 as shown in FIG.
The liquid flows forcefully from an injection port (gate) 5 provided at the upper part of the lower mold 3 into a mold space 4 consisting of an upper mold 2 and a lower mold 3 which sandwich the mold.

However, the injection port 5 is generally provided on a surface portion of the upper mold 2 or the lower mold 3.

Therefore, the injection port 5 is located on one side of the lead frame 1, and the inflowing resin obliquely collides with the guide rod 6 closest to the injection port 5.

As a result, a shadow appears on one side of the ribbon 6 (the upper side in the figure).

After resin molding, a void 7 is generated at this position.

This air pore 7 is also a cause of moisture infiltration, resulting in a decrease in the moisture resistance of the semiconductor device, which is undesirable.

Therefore, it is conceivable to form gates by providing grooves on the lower surface of the upper mold and the upper surface of the lower mold, respectively, but if gates are provided on the upper and lower sides.

As shown in Figure 2, the resin solidification part 8 of the main runner
There is a drawback that the lead frame 23 is embedded in the resin solidified portion 10 of the sub-runner that connects the mold part 9 and cannot be easily separated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the moisture resistance of a semiconductor device and to provide a sealing device that can easily separate a mold portion from a solidified resin portion used for injection.

Hereinafter, the present invention will be explained in detail using Examples.

FIG. 3 shows a portion of the sealing device of the present invention, viz.

The plane of the mold is shown.

As shown in FIG. 4, the mold mold consists of an upper mold 11 and a lower mold 12.
and when stacked on top of each other, a plurality of side-by-side mold spaces 13 and a main launch (resin flow path) 14 extending to the side of the mold spaces 13 are formed. Further, a sub-runner (resin flow path) 15 connecting the main runner 14 and each mold space 13 is formed.

Further, two sub-runners 15 are arranged for one mold space 13.

One of these sub-runners 15 is provided on the lower surface of the upper mold 11 and the other is provided on the upper surface of the lower mold, and the mold space 13
The resin injection ports 16 facing each other overlap with each other.

However, the connecting portions 17 of the sub-runner 15 and the main runner 14 are separated from each other as shown in FIG.

On the other hand, an air vent hole 18 is provided on the side of the mold space opposite to the sub-runner 15, and as the resin flows into the mold space 13, the mold space 13
The air inside flows out.

Next, the sealing method will be described. As shown by chain lines in FIG. 3, the semiconductor element 19 and wires 20 are attached, and the lead frame 21 is set in a mold.

At this time, the semiconductor element 19 is positioned at the center of the mold space 13.

Then, semiconductor element 19. Wire 20. The inner end of the lead 22 is located within the mold space 13, and the lead frame 2
1 outer frame 23. Inner frame 24. Dam 2 connecting each lead 22 etc.
5 etc. are held between the upper mold 11 and the lower mold 12.

In this state, the molten resin 26, which is press-fitted into the main in-runner 14, flows into the mold space 13 through the two sub-runners 15.

At this time, since the resin 26 flows along the upper and lower edges of the outer frame 23, the resin 26 moves to the upper and lower surfaces of each lead 22 while deworming, and no air bubbles are generated as in the conventional case.

Therefore, a semiconductor device with good moisture resistance can be obtained.

After molding, the upper die 11 is removed and the knockout pin 27 attached to the lower die 12 is pushed up to take out the molded product.

FIG. 5 shows a part of the molded product taken out.

In this figure, the molded portion 28 is indicated by a chain line and is the resin solidified portion of the main sub-runner 14,15.

That is, the main coagulation portion 29. The sub-solidified portion 30 and a portion of the outer frame 23 of the lead frame are shown in solid lines.

As shown in the figure, when the molded product is taken out from the lower mold 12, the mold part 28, the main/sub solidified parts 29, 30, and the lead frame are taken out as one piece.

Therefore, since the sub-solidified part 30 is thin, it is cut at this part and the sub-main solidified part 30.2 is cut from the mold part 28.
9 is separated, and unnecessary lead frame portions are cut and removed to obtain a semiconductor device.

As described above, according to one aspect of the present invention, air bubbles are not generated inside the mold portion, so that moisture resistance is improved and reliability of the semiconductor device can be improved.

Further, according to the present invention, the unnecessary solidified resin portion after molding can be easily cut and removed, thereby improving work efficiency.

Furthermore, according to the present invention, two sub-runners are provided as flow paths for resin to the mold section.

Since the parts facing the mold space, ie, the resin inlet part, are together, they are mixed with each other and flowed in, and there is no problem such as a particular decrease in the strength of a part of the mold part.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing the sealed state of a conventional semiconductor device, FIG. 2 is a partial perspective view showing the resin molded state at the time of molding with the improved sealing device, and FIG.
The figure is an explanatory view showing a partial plane of the sealing device for a semiconductor device of the present invention, FIG. 4 is a sectional view taken along line IV-IY in FIG. 3, and FIG.
The figure is a partial perspective view showing the relationship between a semiconductor device sealed by the sealing device of the present invention and solidified resin. 1...Lead frame, 2...Mold upper mold. 3...Mold lower mold, 4...Mold space, 5...Injection port (gate), 6...
...Reed, 7...Void, 8
・・・・・・Resin solidification part of main runner, 9...
...Mold part, 10...Resin solidification part of subrunner, 11...Upper mold, 12...
Lower mold. 13...Mold space, 14...Main runner. 15...Subrunner, 16...Resin inlet. 17... Connection portion, 18... Air vent hole, 19... Semiconductor element, 20... Wire, 21... Lead frame 22...
・Lead, 23...Outer frame, 24...Inner frame, 25...Dam, 26...Resin,
27...Knockout pin, 28...
Mold part, 29... Main solidification part, 30.
...Sub-coagulation part.

Claims (1)

[Claims] 1. In a sealing device that includes an upper mold and a lower mold that sandwich a lead frame from above and below, and a resin injection port that injects resin into a mold space formed by the upper mold and the lower mold, the resin injection port is marked with @. The resin injection ports are provided in the upper mold and the lower mold, respectively, and are arranged so as to overlap with each other, and the resin flow paths from the main runner to the resin injection ports are separated from each other. A sealing device characterized by being a channel.