KR0121648Y1 - Mold die without a gate - Google Patents

Abstract

The present invention is to install an eject pin at the site instead of installing a gate that connects the runner and the cavity so that the function of the eject pin and the gate function can be performed at the same time. By reducing the number and reducing the traces of the eject pin remaining after the package is formed, the marking area can be obtained during the marking process.

Description

Gateless Mold Dies

Figure 1a is a partial plan view of a typical lower mold die.

FIG. 1B is a cross-sectional view taken along the line A-A of FIG. 1A.

2 is a partial cross-sectional view of the present invention.

Figure 3a is a partial cross-sectional view of the pre-clamping state of the present invention.

Figure 3b is a partial cross-sectional view of the post-clamping state of the present invention.

* Explanation of symbols for main parts of the drawings

10: Runner block 10A: Runner

10B: Runner Block Gate 20: Cavity Block

20A: Cavity 30,30A: Eject Pins

50: space

The present invention relates to a semiconductor mold die, and more particularly to a mold die that does not constitute a gate.

The mold die is an apparatus used for encapsulation of a lead frame in which die attach and wire bonding is completed, and is classified into a lower die and an upper die.

The upper and lower dies each include a runner block integrated with a chase block and a cavity block on both sides thereof.

In detail, FIG. 1A is a partial plan view of a lower die among general mold dies, and FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A, and the cavity block 2 is disposed on both sides of the runner block 1. In this position, the cavity 2A having a predetermined depth is formed on the surface of each cavity block 2.

The runner 1A formed at a predetermined depth on the surface of the runner block 1 communicates with each cavity 2A by gates 1B and 2B formed over the runner block 1 of each cavity block 2. The molding compound is injected into each cavity 2A through the runner 1A and the gates 1B and 2B. (Each gate 1B and 2B is selectively configured on the lower die or the upper die.)

At the bottom of each cavity 2A, an eject pin 3 is provided to easily separate the molding compound cured in the cavity 2A.

As described above, the problem occurring when using the mold die formed in the eject pin of the gate and the cavity bottom will be described.

(A) The gate 2B, which has a predetermined depth on the surface of the cavity block 2 corresponding to the tip of each cavity 2A, is repeatedly worn and thus wear occurs, thereby smoothing the molding compound into the cavity 2A. No injection is made.

In this case, since the entire cavity block 2 needs to be replaced, an increase in economic loss occurs that the normal cavity 2A cannot be used.

(B) In order to easily separate the hardened molding compound inside the cavity 2A, the end of the eject pin 3 provided at the bottom of each cavity 2A is flush with the bottom of each cavity 2A. Unevenness (roughness) caused by the eject pin 3 occurs on the surface of the cured molding compound. The marking state becomes poor due to the non-uniformity of the package surface appearing in the marking process for displaying the manufacturer and product characteristics on the package surface, thereby limiting the marking area of the package surface.

(C) If the eject pin 3 is not installed in order to prevent this, excessive force may be applied to separate the hardened molding compound in each cavity 2A, which may cause damage to the package.

The present invention is to solve the above-mentioned problems caused by the gate and the eject pins of the mold die, and by installing the eject pins adjacent to the gate portion of the runner block without forming a gate, the function of the gate and the eject pins It relates to a mold die configured to perform a unique function together.

Hereinafter, with reference to the accompanying drawings of the present invention will be described in detail.

1A is a partial plan view of a typical lower mold die.

FIG. 1B is a cross-sectional view of FIG. 1A taken along a temporary line, and thus description thereof will not be repeated.

2 is a partial cross-sectional view of the present invention, showing a molding die and a lower die together.

A runner 10A and a gate 10B are formed in the runner block 10 of the forming die, and a cavity 20A is formed in the cavity block 20, respectively, as in the dies shown in FIGS. 1A and 1B.

A feature of the present invention is that the eject pin 30 is provided on the surface of the cavity block 20 corresponding to each gate 10B of the runner block 10 without forming a gate. The lower end of the eject pin 30 is formed so as to span the gate 10B edge of the runner block 10 and the cavity 20A edge formed in the cavity block 20. In each cavity block 20 of the upper die, only one eject pin 30A is installed so as to correspond to each cavity 20A.

When explaining the function of the present invention as described above, Figure 3A is a cross-sectional view of the upper and lower die die before the clamping state of the present invention, in the state before the upper and lower die die clamping the runner gate 10B of the runner block 10 On the bottom of the eject pin 30 installed in the upper surface of the cavity block 20 of the die die is made horizontal.

In this state, when the lead frame is seated in the cavity 20A of the cavity block 20 and the upper die is pressed and clamped, the state of FIG. 3B is obtained.

3B is a cross-sectional view after clamping the upper and lower dies. When the upper die is pressed except for the eject pin 30A provided at the edge of the gate 10B of the runner block 10, the upper die and the lower die are brought into contact with each other. Each cavity configured in the cavity block of the lower die forms the enclosed space 40, but the eject pin 30 installed near the cavity 20A of the upper die maintains the initial installation state.

Accordingly, a space 50 having a predetermined height is generated between the ejection pin 30 mounting surface of the upper die and the lower die 60 corresponding thereto, and the height of the space 50 is equal to the moving height of the upper die.

In other words, the upper die is lowered by a certain length, but because the eject pin 30 is fixed, the result is that the eject pin 30 rises.

Therefore, the upper die die space into which the eject pin 30 is inserted is formed into an empty space.

This space 50 communicates the gate 10B formed near the runner 10A of the runner block 10 and the cavity 20A of the cavity block 20 with each other, thus molding compound injected into the runner 10A. Is injected into the cavity 20A through the space 50 formed under the gate 10B and the eject pin 30 of the runner block 10.

On the other hand, since the eject pin 30 is installed at the edge of the cavity 20A, only one eject pin 30A needs to be installed on the upper portion of the cavity 20, so that the marks caused by the eject pin on the surface of the package during the marking process after the molding process. This reduces the amount of space in the marking area can be carried out the marking process.

The present invention as described above can solve the problem of the wear of the gate by installing the eject pin in the position where the gate of the cavity block is formed, and the number of marks remaining on the package surface is reduced by reducing the number of eject pins installed in the cavity Both can afford the surface marking process.

Claims (1)

A runner block including a runner and a plurality of gates communicating with the runner, a plurality of gates corresponding to each gate of the runner block in a one-to-one correspondence, and a plurality of cavities communicating with each gate, each ejector pin corresponding to each cavity In the upper mold die composed of the installed cavity block and the lower mold die corresponding thereto, the cavity 20A of each cavity block 20 adjacent to each gate 10B configured on the runner block 10 of the upper mold die. When the upper and lower mold dies are pressurized by installing an eject pin 30 instead of a gate at the edge, a space 50 is formed at an installation portion of the eject pin 30 so that the space 50 is the runner block 10. And a runner (10A) and a gate (10B) of each of the cavities and the respective cavities (20A) of the cavity block (20).