JPH04340730A - Gate breaking method in sealing process of semiconductor device - Google Patents

Abstract

PURPOSE:To easily set the sectional area of the gate part of a metal mold, by releasing a runner and a package by cutting a gate with a cutting tool. CONSTITUTION:A gate 4 is cut with a cutting tool 3, thereby releasing a runner 5 and a package 8. For example, a lead frame 1 wherein resin sealing is finished is fixed with a lead frame clamp 2. A rotating diamond blade 3 is made to ascend aiming the end surface of a gate 4 side package 8, and gate breaking is performed by cutting the gate 4 with precision wherein the gate residue is 0.1mm at its maximum. Thereby the generation ratio of gate residue failures and the geration ratios of package cracks and lead nicks in a cutting and a bending processes become almost 0%. Since the gate residue caused by excessive sectional area of the gate part is not necessary to be considered, the setting of the sectional area of the gate part is made easy. Further, the sectional area of the gate part can be increased, so that the flow of resin becomes smooth and the generation ratio of voids and parts which are not filled can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate breaking method in a semiconductor device sealing process, and more particularly to a gate breaking method using a cutting tool.

0002

2. Description of the Related Art In a conventional gate breaking method in a semiconductor device sealing process, as shown in FIG. By bending in the direction, stress was concentrated at point B of the gate portion 4 and gate breaking was performed. At this time, if the cross-sectional area of the gate portion 4 at point B is too large, a so-called gate residue will occur where a portion of the gate portion 4 remains in the package 8. For this reason, it is necessary to make the cross-sectional area of the gate section 4 at point B as small as possible so that the gate section 4 can easily break from point B.

0003

[Problems to be Solved by the Invention] In such a conventional gate breaking method, if the cross-sectional area at point B of the gate portion 4 is too large, a gate remains, resulting in package cracks and lead dents during the cutting and bending process. etc., was the cause. Furthermore, if the cross-sectional area at point B of the gate section 4 is made smaller as a countermeasure against remaining gates, this has the disadvantage of increasing the incidence of voids and unfilling. The problem was that it was difficult.

[0004] The purpose of the present invention is to solve the above problems, and
It is an object of the present invention to provide a gate breaking method in a sealing process of a semiconductor device in which the cross-sectional area of a point can be easily set.

[0005]

Means for Solving the Problems The gate breaking method in the sealing process of a semiconductor device according to the present invention is characterized in that the gate is cut with a cutting tool to separate the runner and the package.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view of a gate breaking method using a diamond blade according to an embodiment of the present invention.

In FIG. 1, in this embodiment, a resin-sealed lead frame 1 is fixed with a lead frame clamp 2. As shown in FIG. Next, the rotating diamond blade 3 is raised to aim at the end face of the package 8 on the side of the gate 4, and the gate 4 is cut with an accuracy such that the gate remaining is at most 0.1 mm, thereby performing a gate break.

[0008]

Effects of the Invention As explained above, in the present invention, the gate is cut with a cutting object and the gate is broken, so that the occurrence rate of gate remaining defects is equal to 1% to 0%, and the cutting, This has the effect of reducing the incidence of package cracks and lead dents to almost 0% during the bending process, and in particular, there is no need to consider gate residue due to excessive cross-sectional area at point B of gate section 4. Another effect is that it becomes easier to set the cross-sectional area at point B of section 4.

Further, according to the present invention, it is possible to increase the cross-sectional area at point B of the gate portion 4, and the flow of the resin becomes smoother, which has the effect of reducing the incidence of voids and unfilled parts.

[Brief explanation of drawings]

FIG. 1 is a front view showing a gate breaking method in the sealing process of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a front view showing a conventional gate breaking method.

[Explanation of symbols]

1 Lead frame 2 Lead frame clamp 3 Diamond blade 4 Gate 5 Runner 6 Runner clamp 7 Center of rotation 8 Package

Claims (1)

[Claims] 1. A gate breaking method in a semiconductor device sealing process, which comprises cutting the gate with a cutting tool to separate the runner and the package.