JPH0229314A - Mold die - Google Patents

Abstract

PURPOSE:To store leaked mold resin in a channel and reduce the down time of a semiconductor manufacturing equipment and its recovery maintenance man-hours by forming a ring-shaped channel on the outer periphery of a sliding pin in a mold die used in the mold process of semiconductor manufacture. CONSTITUTION:An ejector pin 21 is of round shape and a main body 7 and a cavity insert 8 are bored commonly and inserted into a pin hole 15 opened in a cavity 8a. Two ring-shaped channels 21a, 21a are with half-round section shape formed on the outer periphery of the end side of the ejector pin 21. Mold resin leaked into a space between the pin hole 15 and the ejector pin 21 are stored in the channels 21a, 21a to form a resin ring on the outer periphery of the ejector pin 21. The resin ring prevents the leakage of the resin to follow to eliminate defective sliding of ejector pin 21 caused by the leakage, and friction deterioration of the pin hole 15 and the ejector pin 12 are eliminated to increase the part life.

Description

[Detailed Description of the Invention] [Summary of the Invention] It relates to molds used in the molding process of semiconductor manufacturing, and more specifically, in the manufacturing process of resin-sealed type semiconductors (plastic ICs), dies, wires, etc. Regarding the mold used to seal wired semiconductor chips with thermosetting resin, we have created a structure that prevents the mold resin from leaking around the mold push-up pins, reducing downtime of semiconductor manufacturing equipment and the number of restoration maintenance steps required. The purpose of this project is to provide a mold that can reduce leakage on the outer periphery of the sliding pin in the part of the mold runner or chase part that comes into contact with the mold resin in the mold used in the molding process of semiconductor manufacturing. The present invention includes a molding die characterized by forming a ring-shaped groove for storing molding resin.

[Industrial application field]

The present invention relates to a mold used in the molding process of semiconductor manufacturing, and more specifically, in the manufacturing process of resin-sealed type semiconductors (plastic ICs), diced and wired semiconductor chips are heated. This invention relates to a mold used for sealing with a curable resin.

[Conventional technology]

In a conventional molding process for semiconductor manufacturing, a diced and wired semiconductor chip is sealed with a thermosetting plastic resin using a transfer molding method. In order to perform this resin molding, a molding die is attached to a molding device.

FIGS. 3(a) and Φ) are perspective views of the upper and lower molds of a conventional molding die. In the same figure, the mold is
It is composed of an upper mold 1 and a lower mold 2.

The upper mold 1 has a pot 3 in which a plunger (not shown) for press-fitting the resin molding material is inserted into the upper mold center block at approximately the center thereof, as shown in Figure (a) (perspective view from the back side). is provided.

The lower die 2 also includes a large number of chase blocks 4. as shown in FIG. A cull portion 5 is formed in the central lower center block, and a runner 6 through which molten resin passes from this cull portion 5 is provided for each chase block 4. It is connected to...

4 is a perspective view of the chase block portion of FIG. 3(1)), and FIG. 5 is an enlarged sectional view taken along line A--A of the chase block of FIG. 4. In these figures, the chase block 4 includes a block body 7, a cavity insert 8, a return spring 9, and a return plate 10.
, ejector plate 11, and ejector bin 12
The mounting consists of a boss 13 and the like. The block body 7 is formed into a substantially elongated rectangular body, and the cavity insert 8 is fitted into a groove 78 formed in the upper part. This cavity insert 8 has a cavity 8a and a gate 8b formed in its upper part, and communicates with a runner 7b formed in the center of the block body 7. A groove 70 is formed in the lower part of the block body 7, and a return plate 10 and an ejector plate 1-11, which are integrated with bolts (not shown), are arranged in the groove 7c, and are attached to the block body 7 with bolts 14. The fixed attachment is guided by a boss 13 to move up and down a predetermined distance. Further, the ejector bin 12 is formed in a round shape, and a head 12a formed with an enlarged diameter at one end is fixed to the return plate 10 and the ejector plate 11, and the other end is a block body 7. The groove 70 of the cavity insert 8 and the cavity 8a of the cavity insert 8 are inserted into a common bottle hole 15. Block body 7
A return spring 9 is disposed between the ejector pin 12 and the return brake 10, and is biased so that the tip of the ejector bin 12 does not protrude from the bottom of the cavity 8a.

In the mold having the above configuration, a lead frame with a die and after wire wiring is set between the upper mold 1 and the lower mold 2 attached to the mold press, and is clamped.

Then, the preheated resin is charged from the pot 3, and pressure is applied from the upper part of the pot 3 with a plunger, and the molten resin passes through the cull part 5 and the runner 6, and then reaches the runner 7b of the chase block 4.

It passes through the gate 8b and is injected into the cavity 8a under pressure, and after cooling, sealing is completed.

Next, in order to take out the molded product IC, the ejector bar of the mold press pushes up the return plate 10 against the biasing force of the return spring 9, so that the tip of the ejector bin 12 protrudes into the gap 8a and molds the IC. The product IC is pushed up. Then, when the mold press is lowered and the mold is opened, the ejector bin 12 is pushed down to its original position by the biasing force of the return spring 9.

[Problem to be solved by the invention]

In the conventional mold, the ejector bin 12 for pushing up the mold of the chase block 4 was simply formed into a round shape. However, in this round-shaped ejector bin 12, under a high-temperature, high-pressure molding environment, when press-fitting the molding resin, the ejector bin 12 and the bin hole 15 of the cavity insert 8 are The mold resin enters between the holes, and a thin resin film 16 is formed on the peripheral wall of the bottle hole 15, causing frequent sliding failures of the ejector bottle 12 and damage to the bottle hole 15 and the ejector bottle 1.
No. 2 wear and tear deterioration occurred. Moreover, the mold push-up pin of the 4th part of the runner was also the same. Therefore, work performed using the mold frequently stops, resulting in downtime and maintenance man-hours, which has become a major problem.

In the mold sealing process, high temperatures (160 to 20
0°C) and high pressure (40 to 80 kg/c), it is necessary to be able to perform initial molding operations even under these conditions. It is necessary to satisfy the accuracy of the mold, the operation such as sliding properties, and the appearance such as the surface finish, product dimensions, and aesthetics of the product.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a mold having a structure that prevents mold resin from leaking around a mold push-up pin, and which can reduce downtime of semiconductor manufacturing equipment and the number of restoration maintenance steps.

[Means to solve problems]

The above problem was solved by forming a ring-shaped groove to collect leaked mold resin on the outer periphery of the sliding pin in the part of the mold runner or chase part that comes into contact with the mold resin in a mold used in the molding process of semiconductor manufacturing. The problem is solved by a molding die characterized by forming.

[Effect]

In the present invention, by forming a ring-shaped groove on the outer periphery of the sliding pin, leaked mold resin collects in the groove, and a resin ring is formed on the outer periphery of the sliding pin. This resin ring prevents subsequent resin leakage.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to an illustrated embodiment.

FIG. 1 is a sectional view of a chase block portion of a mold according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the ejector pin portion of FIG. 1. Note that parts corresponding to the conventional example are denoted by the same reference numerals.

In these figures, the ejector pin 21 has a substantially round shape similar to the conventional example, and is inserted into a bottle hole 15 that is bored in both the block body 7 and the cavity insert 8 and opened in the cavity 8a. At the end of the ejector bin 21, two ring-shaped grooves 21a, 21a having a semicircular cross section are formed on the outer periphery. The width (d) and depth (1) of such groove 21a are:
When the outer diameter of the ejector pin 21 is D, it is preferable to form it to approximately t.(1/100 to 1/200)D d=(1/20 to 1/40)D.

In the mold having the above configuration, the two ring-shaped grooves 21a, 21a are formed on the outer periphery of the ejector pin 21, so that the mold resin leaking into the gap between the bottle hole 15 and the ejector pin 21 is absorbed into the grooves 21a, 21a. A ring of resin is formed around the outer periphery of the ejector pin 21.

This resin ring prevents subsequent resin leakage. Therefore, the sliding failure of the ejector pin 21 due to resin leakage, which was a drawback of the conventional example, and the abrasion deterioration of the bottle hole 15 and the ejector bottle 12 are eliminated, and the life of the parts is improved. In other words, the ejector bin 21 is used approximately once a month for each conventional model.
Whereas cleaning was previously required, this can now be extended from once every six months to once a year, reducing downtime for semiconductor manufacturing equipment. Furthermore, there is no wear caused by resin leakage, and the life of the ejector bin 21 can be extended by about 3 to 5 times compared to the conventional one.

In the above embodiment, the ejector pin 21 of the chase block part was explained as an example, but it can be similarly applied to other parts that come into contact with resin, such as sliding pins of the runner ejector and cal ejector part. be.

Further, the shape, number, etc. of the grooves of the sliding pins may be formed into a ring shape so as to collect leaked mold resin, and the number of sliding pins used is not limited to the embodiments.

〔Effect of the invention〕

As explained above, according to the present invention, by forming a ring-shaped groove on the outer periphery of the sliding pin, leaked mold resin collects in the groove, and this resin ring prevents subsequent resin leakage. . Therefore, it is possible to reduce downtime of semiconductor manufacturing equipment and the number of man-hours required for restoration and maintenance thereof.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the chase block portion of the embodiment of the present invention, Fig. 2 is an enlarged view of the ejector bin portion of Fig. 1, and Fig. 3 is a perspective view of a conventional mold. is a view of the upper die, (b) is a view of the lower die, Fig. 4 is a perspective view of the chase block part in Fig. 3, and Fig. 5 is an enlarged sectional view taken along line A-A of the chase block in Fig. 4. , FIG. 6 is a diagram showing a conventional resin leakage state. 21 is an ejector bin, and 21a is a groove.

Claims (1)

[Claims] In a mold used in the molding process of semiconductor manufacturing, leaked mold resin is collected on the outer periphery of a sliding pin (21) in a part of a mold runner or chase part that comes into contact with the mold resin. A molding die characterized by forming a ring-shaped groove (21a).