JPS6294312A - Mold - Google Patents

Abstract

PURPOSE:To make the replacement of a mold main body easier and to improve processability of package molding of products in a small quantity and varied types, by setting an ejector pin for taking out a molded product on the outer part of the mold main body. CONSTITUTION:Ejector pins 11 are extendedly set in the insides of ejector pin guides 10 under a condition movable to the perpendicular direction on both sides of a mold main body 7 set on a mold plate 8, and the end parts of larger diameter 12 of the ejector pins 11 are put in ejector pin holders 13 and a backing plate 14 is fixed on the end surface side. The ejector pin holders 13 are usually energized to the outer direction of the mold plate 8 by means of a spring 15 and pushing action of the ejector pins 11 of both sides can be done by pressing the backing plate 14 mechanically or manually. As described above, no ejector pin is provided inside of the mold main body, and only taking off the mold main body 7 from the mold plate 8 therefore sufficient enough for replacing the mold main body 7.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a technique that is effective when applied to molds, particularly molds used for package molding in the manufacturing process of resin-sealed semiconductor devices. ] In the manufacturing process of a resin-sealed semiconductor device, a lead frame, which is an object to be molded, is placed in a cavity of a mold consisting of an upper mold and a lower mold so as to be sandwiched therebetween, and the lead frame is placed in the cavity of the mold, and By injecting resin into and curing it,
It is known to mold a package into a predetermined shape.

Incidentally, it is known that the mold is provided with an ejector pin that performs an ejecting operation perpendicularly toward the cavity so that the package-molded lead frame can be easily taken out.

However, this ejector pin has its end fixed to the ejector pin holder and backing plate, and extends to the cavity through the mold plate and the mold body so that it can move up and down, so if the mold body is replaced. The inventor has clarified that when necessary, members such as the ejector plate and ejector pin must be removed, which complicates the replacement work of the mold body. It was done.

Furthermore, the present inventors have also revealed that the complexity of the mold body replacement work reduces the workability in package molding of small-volume, high-mix products, which requires frequent replacement of the mold body.

In addition, since the mold with the above structure has an ejector pin that directly pushes out the package body, when taking the product out of the mold, the resin part of the pan cage body may be damaged or pin marks may remain on the package surface. The inventors have also discovered that there are problems such as the following.

An example of a mold for molding a package of a resin-sealed semiconductor device is "Integrated Circuit Handbook JP420 to P424, published by Maruzen Co., Ltd., November 25, 1961.

[Object of the Invention] An object of the present invention is to provide a technique that allows easy replacement of a mold body.

Another object of the present invention is to improve workability in forming pancakes for small-volume, high-mix products.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

In other words, by providing an ejector pin for ejecting the molded product on the outside of the mold body, which is the molding part,
Since there is no need to extend the ejector pin inside the mold body, the mold body can be easily replaced, and workability in pancage molding for small-lot, high-mix products can be improved.

[Example 1] FIG. 1 is a partial sectional view showing a molding die which is an example of the present invention.

The molding die 1 of the first embodiment is used to mold a package of a resin-sealed semiconductor device, and the molded object is a lead frame 4 on which a pellet 2 and a wire 3 are attached.

The molding die 1 is composed of a mold 5 and a lower mold 6, but since it has a symmetrical structure, only the lower mold 6 will be explained below.

A mold body 7 for performing package molding is detachably attached to a template plate 8 by means such as bolts (not shown). A cavity 9, which is a molding part, is formed in the mold body 7, and an epoxy resin or the like, which is a molding material, is injected into the cavity 9 through a lunch or the like (not shown). Further, ejector pin guides 10 are provided on both sides of the mold body 7, and an ejector pin 11 extends vertically movably inside the ejector pin guide IO.

The ejector pin 11 has a large diameter portion 12 at its end, and this large diameter portion 12 is housed in an ejector pin holder 13, and a banking plate 14 is attached to the end surface side. This ejector pin holder 13 is normally biased toward the outside of the template 8 by a spring 15, and by mechanically or manually pressing the backing plate 14, the ejector pins on both sides are pressed. 11 ejection operations can be performed.

The upper mold 5 also has the same structure as the lower mold 6 described above, and therefore is given the same reference numeral in FIG. 1 and the explanation thereof will be omitted.

Next, the operation of this embodiment will be explained.

First, the upper mold 5 and lower mold 6 of the mold die 1 are opened,
When the lead frame 4, which is the object to be molded, is placed at a predetermined position on the lower mold 6, the upper mold 5 and the lower mold 6 are closed, and the resin 16 is injected into the cavity 9. When the resin 16 hardens and package molding is completed, the upper mold 5 and lower mold 6 are opened and the pancage molded lead frame 4 is taken out.

At this time, when the backing plate 14 is pressed against the biasing direction of the spring 15, the ejector pin 11 operates to protrude the frame portion 4a of the lead frame 4. The glued frame 4 can be easily removed from the mold body 7 by being lifted up from the mold body 7.

In this way, according to the first embodiment, the ejector pin 11
is provided on the side of the mold body 7 to protrude the frame portion 4a of the lead frame 4, and no ejector pin is provided inside the mold body 7. Therefore, when replacing the mold body 7, it can be done simply by removing the mold body 7 from the template plate 8. For this reason,
The mold body 7 can be replaced extremely easily, thereby improving workability in package molding for small-lot, wide-variety products.

Further, since the ejector pin 11 does not penetrate through the mold body 7, the structure of the mold body 7 is simplified, and the mold body 7 can be provided at low cost.

Furthermore, when removing the lead frame 4 from the molding die 1 after completion of the Pasono 1D molding, the ejector pin 11 does not press the resin part 16, which is the package body, so no pin marks remain. Damage to the package body can be prevented.

Furthermore, according to this molding die 1, the end of the ejector pin 11 is not exposed on the circumferential surface of the cavity 9, so that package molding can be performed with no pin marks remaining and the surface being flat. .

As a result, marking on the package surface (resin portion 16) can be performed satisfactorily.

[Embodiment 2] FIG. 2 is a partial sectional view showing a molding die according to another embodiment of the present invention.

The mold die 21 of the second embodiment is almost the same as the mold l described in the first embodiment, but the ejector pin 11 is ejected not from the lead frame 4 but from a loading jig. The difference is that it is applied to 22.

That is, according to the second embodiment, first, the lead frame 4, which is the object to be molded, is placed on the loading jig 22 and supplied to a predetermined position on the lower mold 6.

Next, when the resin 16 injected into the cavity 9 hardens, the upper mold 5 and the lower mold 6 are opened, and the lead frame 4 on which package molding has been performed is taken out from the molding die 21. At this time, the ejector pin 11 operates to press the loading jig 22.

In this way, according to the second embodiment, the ejector pin 11
Since the loading jig 22 is pressed without directly pressing the lead frame 4, deformation of the lead frame 4 due to protrusion of the ejector pin 11 can be prevented.

Note that the other structure of the mold die 21 is similar to the mold die l described in the first embodiment.

[Effects] (1) By providing the ejector pin for ejecting the molded product on the outside of the mold body, which is the molding part, there is no need to extend the ejector pin inside the mold body. The main body can be easily replaced.

(2) According to (1) above, the mold body can be easily replaced, so that workability in buff cage molding for small-volume, high-mix products can be improved.

(3) According to (1) above, the structure of the mold body can be simplified, so that the mold body can be provided at low cost.

(4) Since the package body is not directly pressed by the ejector pin, damage to the package body can be prevented when taking out the molded product.

(5) Since the end of the ejector pin is not exposed on the circumferential surface of the cavity, the package can be molded with a flat surface.

(6) According to (5) above, the surface of the puff cage can be marked well.

(7) By having a structure in which the ejector pin operates to project the loading jig, deformation of the lead frame due to the ejector pin can be prevented.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

[Field of Application] In the above explanation, the invention made by the present inventor was mainly applied to the field of application, which is a mold die used for molding a package of a so-called resin-sealed semiconductor device. The present invention is not limited to this, and is an effective technique even when applied to molds for forming packages of molded products such as other electronic parts or mechanical parts.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing a molding die according to a first embodiment of the present invention, and FIG. 2 is a partial cross-sectional view showing a molding die according to a second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Mold die, 2... Pellet, 3... Wire, 4... Lead frame, 4a... Frame part, 5...
...Top mold, 6...Bottom mold, 7...Mold body, 8...
Template plate, 9... Cavity, IO... Ejector pin guide, 11... Ejector pin, 12... Large diameter part, 13... Ejector pin holder, 14... Banking plate, I5...・Spring, 16...Resin (pan cage body), 21...Mold die, 22...Loading jig.

Claims (1)

[Scope of Claims] 1. A molding die characterized in that an ejector pin for ejecting a molded product is provided on the outside of the mold body, which is a molding section. 2. The mold according to claim 1, wherein the ejector pin operates by ejecting the lead frame. 3. The mold according to claim 1, wherein the ejector pin operates to eject the loading jig. 4. The mold according to claim 1, wherein the molded product is a resin-sealed semiconductor device.