JPS63280607A - Molding device - Google Patents

Abstract

PURPOSE:To remove molding resin accumulated in a channel easily by providing a tapered channel in a section where a plunger to press molding resin into cavities of a top and a bottom mold comes into contact with a pump for fitting. CONSTITUTION:Molding resin heated preliminarily is put into a pot 2 and pressed into cavities 3a and 4a by a plunger 1 to manufacture a semi-conductor device. At that time, at the end of the plunger 1, a tapered channel 1a is provided. When the molding resin is pressed into the pot 2 by the plunger 1, the molding resin is accumulated in the channel 1a to prevent the molding resin in the mold from leaking. The molding resin accumulated in the channel 1a however, should be removed as the same wears the side wall of the pot 2. Said molding resin is of a ring shape of a wedge-shaped section and can be removed by an air gun, a brass bar or the like easily.

Description

[Detailed Description of the Invention] [Summary] A tapered groove is provided in the part of the plunger that fits into the pot of the plunger that press-fits the mold resin into the cavities of the joined upper and lower molds of the molding die. A molding device that makes it possible to easily remove accumulated mold resin.

[Industrial application field]

The present invention relates to a molding device, and particularly to the structure of a plunger for press-fitting a molding resin into a molding die.

2. Description of the Related Art In a mold used in a molding device used in the final process of manufacturing mold-type semiconductor devices, a combination of a plunger and a pot are used to press-fit molding resin.

A groove is provided in the fitting portion of the plunger with the pot, and the mold resin is collected in the groove to prevent the mold resin from leaking from the gap between the plunger and the pot.

However, the mold resin accumulated in this groove is 10 to 2
Since it must be removed for every 0 shot, it is necessary to be able to remove it easily.

Under the above circumstances, there is a need for a molding device that can easily remove the molding resin accumulated in the groove of the plunger.

[Conventional technology]

As shown in FIG. 2, the molding die of the conventional molding device has a lead frame 5 on which a semiconductor element 6 is mounted between an upper mold 3 and a lower mold 4, and the semiconductor element 6 mounting portion is placed between the upper mold 3 and the lower mold. Set the upper mold 3 so that it is positioned in the cavities 3a and 4a of the mold 4. A preheated mold resin is put into a pot 2 provided in a pot 2, and a plunger 11 that fits into the pot 2 is used to press fit the mold resin into the cavities 3a and 4a to manufacture a semiconductor device.

The details of the conventional plunger 11 are shown in FIG. 3, in which a circular or oval groove 11a is machined at the tip of the plunger 11 that fits into the pot 2.

However, although the mold resin accumulated in this groove is effective in preventing leakage of the mold resin, it also causes wear on the side walls of the pot 2.

[Problem that the invention seeks to solve]

The problem with the molding die of the conventional molding device described above is that the mold resin accumulated in the groove of the plunger causes severe wear on the side wall of the pot, so the mold resin accumulated in this groove is removed every 10 to 20 shots. This is something that must be removed.

The mold resin accumulated in this groove is necessary to prevent leakage of the mold resin that is press-fitted, but on the other hand, it abrades the side walls of the pot.

As a countermeasure to this problem, various investigations and experiments were conducted regarding the material and surface treatment of the plunger, but it was found that making it easier to remove the resin accumulated in the groove was more effective than the problem of material or surface treatment.

The present invention aims to provide a molding device that can solve the above-mentioned problems with a simple structure.

[Means for solving problems]

The above problem can be solved by a molding device according to the present invention in which a tapered groove is provided in the portion of the plunger that fits into the pot of the plunger that press-fits the mold resin into the cavities of the joined upper and lower molds of the molding device. solved by.

[Effect]

That is, in the present invention, tapered grooves are provided in the four portions of the plunger that fit into the pot of the plunger that press-fits the mold resin into the cavities of the joined upper and lower molds of the mold, so that no dirt accumulates in these grooves. Since the molded resin has a very thin cross-section, it can be easily and easily removed using an air gun, a brass rod, or the like.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

The overall structure of the molding die is completely the same except that the plunger 11 of the molding die shown in FIG. 2 is replaced with the plunger 1.

Put the preheated mold resin into pot 2,
Plunger 1 fits into mold resin into cavity 3.
A and 4a are press-fitted to manufacture a semiconductor device.

As shown in FIG. 1, a tapered groove 1a is formed at the tip of the plunger 1, which fits into the pot 2 provided on the upper mold 3.

In this embodiment, the depth of this groove 1a is 0.5 mm, and the width is 2 mm.

When the mold resin is press-fitted into pot 2 with plunger 1, the ? The mold resin accumulates in the ila, making it possible to prevent the mold resin from leaking inside the mold.

However, the mold resin accumulated in this groove 1a is removed from the pot 2.
This mold resin must be removed every 10 to 20 shots as it wears out the side walls of the mold, but as mentioned above, this mold resin has a maximum thickness of 0.5 + (0.02 to 0.04)■
, the minimum is half the difference between the inner diameter of pot 2 and the outer diameter of plunger 1, about 0.02 to 0.04 m1, and the length is in the shape of a ring with a cross section of a model of 211, so air guns, brass It is possible to simply remove the knot with a stick or the like.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a groove with an extremely simple structure in the fitting part of the plunger with the pot, it becomes possible to easily remove the mold resin accumulated in this groove. It has advantages such as being able to prevent the side wall of the pot from being worn out by the molding resin, and can be expected to have a significant economical and reliability improvement effect, making it extremely useful industrially.

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing the main parts of a mold according to an embodiment of the present invention, Fig. 2 is a side sectional view showing the main parts of a conventional mold, and Fig. 3 shows a conventional plunger. It is a side sectional view. In the figure, 1 is a plunger, 1a is a groove, 2 is a pot, 3 is an upper mold, 3a is a cavity, 4 is a lower mold, 4a is a cavity, 5 is a lead frame, and 6 is a semiconductor element. FIG. 1 is a side sectional view showing the main parts of a mold according to an embodiment of the present invention. FIG. 2 is a side sectional view showing the main parts of a conventional mold. FIG. 3 is a side sectional view showing a conventional plunger.

Claims (1)

[Claims] The part of the plunger (1) that press-fits the mold resin into the cavities (3a, 4a) of the joined upper mold (3) and lower mold (4) of the molding die, which is fitted with the pot (2), has a tapered shape. A molding device characterized in that a groove (1a) is provided.