JPS63124428A - Sealing apparatus for semiconductor - Google Patents

Abstract

PURPOSE:To prevent the occurrence of flash burrs and also the deformation of a lead frame, by forming a plurality of slit grooves on either upper surface side or lower surface side of at least one of upper and lower stationary platens. CONSTITUTION:Grid-shaped slit grooves 40a-40f are formed by machining on the surface of a lower stationary platen 40 to which the main tool of a mold is fitted, while slit grooves 40g-40j are formed by machining on the rear surface of the platen. The structure of a top force is the same with that of a bottom tool. Although a temperature difference occurs between the upper part of the stationary platen 40 and the lower part thereof in the course of sealing operation with resin in an apparatus constructed as stated above, the amount of a shell-like change in each part of the platen is made small by the provision of the grooves 40a-40j. When the shell-like change is modified, on the other hand, only a small force of modification needs to be applied in addition to a clamping force due to the existence of the grooves 40a-40j, and thus the force of modification of the change in the shape can be reduced sharply. Accordingly, a pressure can be applied to a lead frame uniformly and efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a semiconductor sealing device for sealing a semiconductor device with resin.

[Conventional technology]

Figures 3 to 6 are diagrams showing this type of conventional structure, and in the figures, flli'j:) transfer bracelet,
Consists of an upper platen (la), a base (:rb), a slide table (lc), and a tie rod (1d).
A transfer cylinder (1e) is installed on the upper platen (1a).
However, a mold clamping cylinder (1f) is attached to each pace (1b). The slide table (1c) is connected to the piston rod of the mold clamping cylinder (1f) and moves up and down. (2) is a plunger head attached to the piston rod of the transfer cylinder (1e).

(3) is the lower mold, which includes a runner (3a), a gate (3b),
The lower mold cavity (3c) is machined and fixed to the lower surface plate (4). (5) is Cal (5a) in the lower center block.
A runner (5b) branching from the cull (5a) is machined and fixed to the lower surface plate (4). Lower center block (
The runner (5b) of 6) is the runner (3a) of the lower mold (3).
are connected to each other. (6) is a guide pin that is press-fitted and fixed to the lower surface plate (4), and when the upper and lower molds are clamped, it slides into the guide bush (I5) that is press-fitted and fixed to the upper surface plate (7). , align the upper and lower molds. (8) is a lower support frame, and (9) is a lower heat insulating plate, which are attached as shown in FIG. 3 and constitute a framework together with the lower surface plate (4).

(lO) is the lower ejector plate) and (II) is the lower holding plate, which is built into the framework of the lower surface plate (4), the lower support frame (8), and the non-insulated plate (9), and is attached to the flange of the ejector bin (12). Hold and install. The ejector pin (12) is attached to the lower surface plate (4).
), the molded product is ejected by penetrating the lower die (31) or the lower center block (5). The ejector plate f101 is pushed back toward the non-insulated plate (9).04) is attached to the base (1b) with the ejector rod.
The lower ejector plate (101) is pushed up from near the bottom dead center of the press, and the ejector bin (121) ejects the molded product.

(16) is an upper mold, which has a processed upper mold cavity (16a) and is fixed to an upper surface plate (7). (171 is the upper center block) It is fitted with (18) and fixed to the upper surface plate (7). (19) is the upper supporting frame, and the shank is the heating plate, which together with the upper surface plate (7) constitute the framework as shown.

(21) is an upper ejector plate, and the upper presser plate (21) is built into the framework, and is attached to the ejector bin (23) and the return pin by holding the flanges thereof. The ejector bin (23) and return pin (24) are connected to the upper surface plate (7).
) and upper mold (181 or upper center block (I71)
Penetrates through to eject the molded product. (Upper ejector plate (2+) and appeal heating plate (2) with 251i-I compression spring.
0) and always upper ejector play 1- @
1) is pushed back toward the upper surface plate (7).

(Foundation) is a lower support bin, and 2 is an upper support bin, each consisting of a lower surface plate (4) and a non-insulating plate (9) or an upper surface plate (7).
It is installed between the top and bottom of the hot plate to prevent the upper and lower surface plates from deflecting due to mold clamping pressure.

(2a, (29) is inserted into the upper and lower surface plates with a heater,
Raise the temperature of the mold.

In the device configured as described above, the resin-sealed semiconductor device is encapsulated with resin using the mold described above. Temperature Beata (Company), (29
) to raise the temperature and properly place the lead frame on the lower mold (3). The mold clamping cylinder (1f) is operated to raise the slide table (1c) and clamp the lower mold and the upper mold. Next, load resin into pot α8) and transfer cylinder (
1e) to lower the plunger head (2), the resin in 181 melts and flows from the cull (5a) to the runner (sb), runner (3a), and gate (3b) in this order, and enters the lower mold cavity. (3C) and the upper mold cavity (16a). When the mold is opened after waiting for the resin to harden, the resin in the upper mold is compressed by the spring pressure of the compression spring □□□. The ejector bin (23) held by the plate (22) is forcibly projected downward to release the mold.Also, the resin in the lower mold is released from near the bottom dead center of the press by the ejector rod (14) into the lower ejector plate. (10) is pushed up and released from the mold by the ejector bin (12).

[Problem that the invention seeks to solve]

Conventional semiconductor encapsulation equipment is configured as described above, and the temperature is raised by heaters inserted into the upper and lower surface plates, so the mold temperature is not uniform throughout and is lower toward the press mounting surface. A temperature gradient occurs.

As a result, the surface temperature of the surface plate on which the upper and lower molds are housed becomes high, and the difference in thermal expansion causes not only the surface plate to deform into a central shell shape, but also the support frame to deform into an arched shape. For this reason, the parting surfaces of the main die that have been defeated by the surface plate are not on the same plane and a gap occurs.

Since the lead frame placed in this gap generating portion is not completely clamped by the upper and lower dies, resin also flows into the gap, causing flash burrs. Lead frames with flash burrs not only cause the problem of not being plated in the subsequent plating process, but also require a process to remove the burrs left on the parting surface of the mold. there were.

Furthermore, there is a problem in that the lead frame placed in the gap generating portion is deformed by the injection pressure, resulting in serious defects in the semiconductor device.

Therefore, in order to alleviate these problems, in conventional mold structures, a thin plate is inserted between the surface plate and the main mold in the area where flash burrs occur, or between the press and the mounting surface of the mold to adjust the mold vibration. Attempts were made to adjust the dimensions of the support frame or support pins, but not only did it take a long time, but it was also incomplete.

Furthermore, in order to correct the deformation of the surface plate and support frame by press mold clamping pressure, the press becomes larger than necessary, which poses problems in terms of cost, space, etc.

This invention was made to solve the above-mentioned problems. It eliminates the occurrence of flash burrs on lead frames, prevents deformation of lead frames, and manufactures high-quality semiconductor devices. It is an object of the present invention to provide an efficient semiconductor sealing device by omitting an adjustment process.

[Means for solving problems]

In the semiconductor encapsulation device according to the present invention, a plurality of slit grooves are arranged in parallel on either the upper surface side or the lower surface side of at least one of the upper and lower surface plates.

[Effect]

The semiconductor encapsulation device according to the present invention has a plurality of slit grooves arranged in parallel, and the force for correcting the shell-like deformation amount by pressure can be achieved with a small pressure force due to the slit grooves.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the lower mold structure;
The structure itself is the same as that explained in the conventional structure, so only the differences will be described.

(40) is a lower surface plate, and the main mold mounting surface has lattice-shaped slit grooves (40a) to (40f), and the back surface thereof has slit grooves (40g) to (40j). The lower surface plate (40) is supported by a lower support frame (6).

The ring is a guide pin and is press-fitted into the lower surface plate (40). ■ is the lower center block, and (c) is the lower mold, each of which is attached to the lower surface plate (40). ) is the lower presser plate, and t4 is the lower ejector plate.

(c) is the lower insulation board, and the opening is the heater insertion hole.

The upper mold structure is also the same as the conventional upper mold structure, so a description thereof will be omitted.

In the structure configured as described above, the semiconductor device is resin-sealed using the upper and lower molds, but the sealing operation itself is the same as that of the conventional type, so a description thereof will be omitted.

By the way, during the resin sealing work, a temperature difference occurs between the upper and lower parts of the surface plate (40), and the amount of deformation of each part is determined by the slit grooves (40a) to (40J) in Fig. 2. On the other hand, when correcting shell-like deformation, it is sufficient to apply a small correction force in addition to the mold clamping force using the slit grooves (40a) to (40'').
The deformation correction force can be significantly reduced, and it is also possible to apply pressure locally.

Therefore, the lead frame is uniformly and efficiently pressurized.

In addition, in the above embodiment, the upper and lower surface plates (n, (40)
Although the slit grooves are shown in Fig. 3 in the form of a lattice, radial grooves may also be used, and the lower support frame (40), (
If 6) is combined with one in which slit grooves have been processed, even more effects can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, since a plurality of slit grooves are arranged in parallel on either the upper surface side or the lower surface side of at least one of the upper and lower surface plates, thermal deformation can be reduced. It is possible to seal high-quality semiconductor devices that can prevent the occurrence of flash burrs and lead frame deformation, and it is not only possible to eliminate flash burr removal work, but also to use press equipment with high efficiency. There are effects that can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a perspective view of the main part thereof, Fig. 3 is a sectional view of a conventional device, Fig. 4 is a plan view of the lower mold, and Fig. 5 is a perspective view of an embodiment of the present invention. FIG. 6 is a bottom view of the upper mold, and a perspective view of the mold. In the figure, (40) is the lower surface plate, (40a) to (40f) are the slit grooves, (6) and 0■ are the lower support frame, and the path is the guide bin.
(2) is the lower center block, (C) is the lower mold, (2) is the lower press plate, 171 is the lower ejector plate, and the decoy is the lower heat insulating plate. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (2)

[Claims] (1) In a semiconductor encapsulation device that has an upper mold and a lower mold supported by upper and lower surface plates, and injects resin into these upper mold and lower mold to resin-seal a semiconductor element, the above-mentioned A semiconductor encapsulation device characterized in that a plurality of slit grooves are arranged in parallel on either the upper surface side or the lower surface side of at least one of the upper and lower surface plates. (2) The semiconductor sealing device according to claim 1, wherein the slit grooves are formed in a grid pattern.