JPS618932A - Method and apparatus for manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To restrain generation of voids by reducing a quantity of the air included in a resin actively by arranging an exhaust vent in the resin introducing part ranging from a lower part of the hole for throwing a mold for resin sealing in to the resin sealing part where a semiconductor chip is resin-sealed and by exhausting the air from said exhaust vent after throwing a resin tablet in. CONSTITUTION:A tablet 6 is put in a pot 5 and a door 13 is shut. At this time, electromagnet valves 17 and 18 open immediately to connect a reduced pressure box 11, the pot 5 and a runner 9 with a buffer box 19 which holds a vacuum of hgh degree and the pressure rapidly falls from the atmospheric pressure to about 1/10 of that, for example. After the reduced-pressure box 11, the pot 5 and the runner 9 are brought in the reduced-pressure state, a plunger 4 is lowered rapidly and its front end 4a presses a fused resin so as to flow it from the runner 9 to a cavity 7. Before the fused resin is flown in the cavity 7, the air is exhausted suddenly from an exhaust vent 15 thereby reducing a quantity of the air included into the resin actively.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical field of the invention The present invention relates to a method for manufacturing a semiconductor device and a semiconductor manufacturing apparatus, and more specifically to voids contained in a resin molded product.
The present invention relates to a resin molding method capable of reducing air pressure and a resin molding apparatus equipped with an inexpensive structure capable of efficiently exhausting air within the mold.

(2) Technology background For example, a semiconductor chip is attached to a lead frame.

In order to resin-seal this chip, a molding device shown in the cross-sectional view of Fig. 4 is used, and in the same figure, 1 is an upper gouer, and 2 is movable in the vertical direction and unites with the upper gou when it rises. The lower die (to be clamped), 3 is a housing to which the upper die 1 is fixed, 4 is a plunger, 4a is the tip of the plunger, 4b is a groove formed in this tip, 5 is a tablet 6 inside it. A pot (sealed chamber) into which a plunger 4 can be inserted and removed; 7 indicates a cavity formed symmetrically between the upper die and the lower die. A lead frame with a semiconductor chip mounted inside the lower cavity 7 is arranged in a direction perpendicular to the plane of the paper, and although there are many such cavities, only two rows are shown as squares in Figure 1 for the sake of simplicity. .

With the lower die 2 clamped, a resin material tablet (generally about 50 centimeters thick,
One or more pieces (having a diameter of about 60 pieces) are inserted through the opening in the upper die 1 located above the plane of the paper as seen in the figure, and are housed below the pot 5, inside the pot 5. The tablet 6 is heated to about 160° C. and melted. When the plunger 4 is lowered and the tip 4a presses the molten resin.

The molten resin material flows into the cavity 7 through the launch provided in the lower die 2 and seals the semiconductor chip.

A ring-shaped groove 4b is cut in the tip 4a of the plunger, and molten resin enters the groove 4b to serve as an O-ring. The plunger tip 4a is placed inside the pot 5.
When it enters, the pot becomes sealed.

As described above, by providing a large number of cavities 7, it is possible to resin-seal a large number of chips in one operation of the illustrated molding device, and a resin-sealed semiconductor integrated circuit package (also called a plastic IC package) is obtained. The mold (equipment) involved in manufacturing is essential.

(3) Problems with the Prior Art In operation of the molding device described above, since the upper portion 8 is open, air is drawn into the pot 5 when the tip portion 4a of the plunger enters the pot 5. The molten resin is then poured into the cavity, and air mixes with the resin.

When a chip is sealed with a resin, a void called a void is created in the resin material, and this state is shown in the cross-sectional view of the cavity in FIG. In FIG. 5 and subsequent figures, the same parts as those already illustrated are denoted by the same reference numerals, and in the figure, 9 is a launch through which the molten resin flows, 10 is a gate, 21 is a lead frame, 22 is a semiconductor chip,
23 indicates a wire for electrical connection between the semiconductor chip and the lead frame, 24 indicates a resin used for sealing 4, and resin 2
4 was put into pot 5 as a bullet in the evening and the runner was 9.
It is molded by entering the cavity through the gate 10.

When the above-mentioned air is mixed with the resin, voids 25 (exaggerated in Figure 3) are created, and the field
In some cases, voids 25 are formed on the surface and can be observed with the naked eye. The presence of such voids has a problem of adversely affecting the strength and moisture resistance of the molded product and increasing the incidence of defective products.

Therefore, the present applicant previously proposed in Japanese Patent Application No. 58-241323 to provide a sealed vacuum box in the upper portion 8 of the pot.

FIG. 6 shows a sectional view of the molding device. In the figure, the fourth
The same parts as in the figure are given the same symbols.

11 is a decompression box, 13 is a door for putting resin tablets in, and 14 is an exhaust port.

By connecting the exhaust port of this device to an exhaust mechanism and reducing the pressure in the vacuum box, the amount of air drawn into the pot 5 when the tip 4a of the plunger enters the pot 5 can be reduced, resulting in the generation of poids. was able to suppress it.

However, when the lower die 2 is raised from the state shown in FIG. 6(a) to be combined with the upper die 1, the resin tablet is introduced, the door 13 is closed, and the air is exhausted from the exhaust port 14.

The resin tablet is heated from around the pot 5.

The surface may melt and adhere to the side wall of the pot 5, as shown in FIG. 6 (bl), almost blocking the pot 5.

At this time, the lower part of pot 5 and the runner.

There is a problem in that the air in the cavity cannot be exhausted, and the air in these parts mixes with the resin when the plunger 4 presses the resin, resulting in voids.

(4) Purpose of the Invention In view of the above-mentioned conventional problems, the present invention improves air exhaust from the bottom of the pot to the cavity, reduces the occurrence of voids, and provides a resin seal with excellent strength and moisture resistance. The purpose of the present invention is to provide a type semiconductor integrated circuit puff cage.

(5) Structure of the Invention According to the present invention, the above object is achieved from the lower part of the inlet of the resin-sealing mold into which the resin tablet is introduced to the resin-sealing part where the semiconductor chip is resin-sealed. A method for manufacturing a semiconductor device, characterized in that an exhaust port is provided in a resin introduction part, and after exhausting the air through the exhaust port and inserting the resin tablet, exhausting the air through the exhaust port to perform resin sealing, and a resin tablet. An exhaust port is provided in the resin introduction part from the lower part of the input port of the mold for resin sealing to be resin-sealed to the resin sealing part for resin-sealing the semiconductor chip, and after the resin tablet is inserted, the resin is exhausted from the exhaust port,
This is achieved by a semiconductor manufacturing apparatus characterized by resin sealing.

(6) Embodiments of the Invention Below, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial sectional view of a resin molding apparatus according to an embodiment of the present invention. In the figure, the same parts as in FIG. 6 are designated by the same reference numerals.

The resin molding apparatus shown in FIG. 1 differs from that shown in FIG. 4 in that an exhaust port 15 connected to a runner 9 is provided. This exhaust port 15 is the exhaust port 1 provided in the decompression box 11.
4 or to a separate exhaust mechanism.

FIG. 2 is a schematic layout diagram showing an exhaust mechanism commonly used for the exhaust ports 15 and 14. FIG. The pressure reduction box 11 and the runner 9 are connected to I via solenoid valves 17 and 18, respectively.
The buffer box 19 is also connected to the exhaust pump 20 .

A method for resin-sealing a semiconductor chip using the resin molding apparatus shown in FIG. 1 will be described below.

First, the door 13 is opened, the resin tablet 6 is put into the pot 5, and then the door 13 is closed. At that time, the solenoid valve 17
and 18 open, vacuum box 11° pot 5 and runner 9
is connected to a buffer box 19 maintained at a high degree of vacuum, and the pressure rapidly drops from atmospheric pressure to, for example, about 1/10 of atmospheric pressure.

Here, the vacuum box 11. After the bot 5 and the runner 9 are in a reduced pressure state, the plunger 4 is rapidly lowered, and its tip 4a presses the molten resin to flow from the runner 9 into the cavity 7.

In other words, according to this embodiment, after the resin tablet 6 is put into the pot 5 and before the molten resin flows into the cavity 7, the molten resin is rapidly evacuated from the exhaust port 15 provided in the runner 9, thereby preventing the mixture from entering the resin. It is possible to actively reduce the amount of air that enters the air, and to manufacture a high-quality resin-sealed semiconductor integrated circuit package free of voids.

In the above embodiment, the exhaust port is provided at one location on the runner 9 as shown in FIG. 1, but it may be provided at multiple locations as shown in FIG. By providing it in the introduction part, it may be provided so that the pressure in the same part can be efficiently reduced.

(7) Effect of invention As described in detail above, according to the present invention.

An exhaust port is provided in the resin introduction section from the bottom of the input port of the resin sealing mold into which the resin tablet is inserted to the resin sealing section where the semiconductor chip is resin-sealed, and after the resin tablet is inserted, the air is exhausted from the exhaust port. By.

By actively reducing the amount of air mixed into the resin, it is possible to manufacture a resin-sealed pancage that suppresses the generation of voids and has excellent strength and moisture resistance, which is highly effective in improving the reliability of semiconductor devices.

[Brief explanation of the drawing]

FIG. 1 is a sectional view for explaining a resin molding device according to an embodiment of the present invention, FIG. 2 is a diagram for explaining an exhaust mechanism according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view for explaining an exhaust mechanism according to an embodiment of the present invention. 4 and 6 are cross-sectional views of a conventional molding device, and FIG. 5 is a cross-sectional view of a resin-sealed semiconductor integrated circuit package having voids. 1... Upper die, 2... Lower die. 3... Housing, 4... Plunger. 4a... tip of the plunger, 4b...
・Groove, 5... Pot, 6... Resin tablet, 7... Cavity. 8... Upper part of the pot, 9... Runner,
10...Gate, 11...Decompression box, 13...Door, 14,15゜16
...Exhaust port, 17.18...Solenoid valve,
19...Buffer Box. 20... Exhaust pump, 21... Lead frame, 22... Semiconductor chip 5, 23... Wire, 24... Resin. 25... Void. Patent Applicant: Fujitsu Limited 74 tier (,,','
:, 'i Representative Patent Attorney Hiroshi Matsuoka yi-,
', 'j 1st Flash Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) An exhaust port is provided in the resin introduction section from the lower part of the input port of the resin mold into which the resin tablet is introduced to the resin sealing section where the semiconductor chip is resin-sealed, and after the resin tablet is introduced, the exhaust port is A method for manufacturing a semiconductor device, characterized by exhausting the air through the mouth and sealing with a resin. (2) An exhaust port is provided in the resin introduction section from the lower part of the input port of the resin sealing mold into which the resin tablet is inserted to the resin sealing section where the semiconductor chip is resin-sealed, and after the resin tablet is inserted, the exhaust port is provided. Semiconductor manufacturing equipment characterized by exhaust air from the mouth and resin sealing.