JPS63228656A - Lead frame for semiconductor device - Google Patents

Abstract

PURPOSE:To simplify an assembling apparatus by omitting a deburring step and to improve abrasion resistance and quality of parts, by preventing the occurrence of dam burr in the direction of die bars with a dam burr stopper when resin molding is performed. CONSTITUTION:A dam burr stopper 7 is connected to a part 301 of a die bar 3 facing a molding resin 6. The dam burr stopper 7 is composed of a longitudinal part 7a, which is connected to a die bar part 301, and a lateral part 7b, which is connected to the tip of the longitudinal part 7a in a T shape. The dam burr stopper is molded with the resin as a unitary body together with the die bar 3 and has the same thickness as an electrode 1, outer electrodes 2 and a frame body 4. They are isolated one another. When the dam burr stopper 7 is provided in this way, a front surface 701 of the dam burr stopper 7 is just positioned on the boundary line of the molding resin. At the time of packaging and molding with the molding resin, a gap between top and bottom forces is filled. Therefore, the resin is not injected between the outer electrodes 2 and between the outer electrodes 2 and the frame body 4, and dam burr is not yielded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in lead frames used for assembling semiconductor devices.

[Conventional technology]

A conventional lead frame for a semiconductor device will be explained with reference to FIGS. 6 to 9. Figure 6 is a front view, Figure 7 is a front view after resin molding, Figure 8 is a sectional view taken along line ■-■ in Figure 6,
Figure 9 is a cross-sectional view along line 1) (-1 in Figure 7. In the figure, (υ is an electrode on which a semiconductor element (not shown) is placed, and (2) is another electrode on the semiconductor element. and Hoso II (not shown)
a plurality of external electrodes connected to and led out to the outside;
(3) is a tie bar that connects and supports each external electrode (2);
4) is the tie bar (3), electrode (1) and each external electrode (2)
It is a frame body that supports and has positioning holes (5) and the like.

(6) is the molded resin, and (6A) is the dam burr generated during resin molding.

When performing sealing with mold resin, the mold resin is injected between the outer electrodes (2) and between the outer electrodes (2) and the frame (4) from the gap between the upper and lower molds (not shown). As it is, the tie bar (3) prevents outflow, and a dam burr (6A) is formed as shown in FIGS. 7 and 9.

[Problem that the invention seeks to solve]

In the conventional lead frame for semiconductor devices as mentioned above,
Since dam burrs (6A) are generated during resin molding, a deburring process is required to remove the damper IJ (6A), which complicates the assembly equipment, and also causes parts to wear quickly and cause damage to external electrodes (2), etc. There was a problem in that the quality deteriorated due to paris implantation.

This invention was made to solve these problems, and by preventing the occurrence of dam burrs, it is possible to simplify assembly equipment by eliminating the need for deburring processes, and to improve the wear resistance and quality of parts. The object is to obtain a lead frame for a semiconductor device as shown in FIG.

[Means for solving problems]

A lead frame for a semiconductor device according to the present invention is provided with a dam burr stopper which is repeatedly cast on a tie bar portion facing a mold resin and has the same thickness as the electrode, external electrode, and frame and is separated from the lead frame.

[Effect]

In this invention, when sealing with mold resin, the T gap between the upper and lower molds is closed by the dambur stopper, so that the gap between the external electrodes and between the external electrode and the frame body is No resin is injected during the process, and no dam burrs occur.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. Figure 1 is a front view, Figure 2 is a front view after resin molding, Figure 3 is a sectional view taken along line i-I in Figure 1, and Figure 4 is a
A cross-sectional view of line IV-IV in the figure, Figure 5 is my-v in Figure 2.
FIG. 2 is a cross-sectional view of the conventional device, in which the same or corresponding parts as those of the conventional device are given the same reference numerals and explanations thereof will be omitted. In the figure, (
7] is a dam burr stopper that is connected to the part (301) of the tie bar a) facing the molded resin (6), and the vertical part (7a) that is repeatedly thrown on the tie bar part (301) and this vertical part (7a ) is connected in a T-shape to the tip of the horizontal part (
7b). This Dambari Topper (
7) is integrally molded in resin with the tie bar (3), and has the same thickness as the electrode (1) to the external electrode (2) and the frame (4), and is separated from the electrode (1) to the external electrode (2).

Providing the damburi stopper (7) in this way,
The front surface (701) of the dam burr stopper (7) is located exactly on the mold resin boundary line and closes the gap between the upper and lower molds during sealing with the mold resin, as shown in Figures 2 and 5G. As a result, no resin is injected between the external electrodes (2) or between the external electrodes (2) and the frame (4), and no dam burrs occur.

Note that if the dam burr stopper (7) is made to have the same thickness as the electrode (1), external electrode (2), and frame (4), the contact between the lead frame and the mold will be reduced when the lead frame is held down by the upper and lower molds. There is no gap in between.Also, throw the Dambari stopper (7) on the tie bar (3 doors in a row) and the electrode (1),
By separating the external electrode (2) and the frame (4), the dam burr stopper (7) can be removed together with the tie bar (3) during the tie bar cutting process.

In the above embodiments, the shape of the lead frame is shown in each figure, but other shapes may be used, for example, the electrode (1) may be connected and supported by the tie bar (3) together with the external electrode (2). It may be of any shape.

〔Effect of the invention〕

As described above, according to the present invention, by preventing the occurrence of dam burrs, it is possible to simplify and reduce the cost of assembly equipment by eliminating the need for a deburring process, and to improve the wear resistance and quality of parts.

[Brief Description of the Drawings] Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is a front view after resin molding, Fig. 3 is a sectional view taken along line 1-1 in Fig. 1, Fig. 4 is a sectional view taken along line IV-IV of No. 10, Fig. 5 is a sectional view taken along @V-V in Fig. 2, Fig. 6 is a front view showing the conventional one, and Fig. 7 is after resin molding. 8 is a cross-sectional view taken along the line ■-■ in FIG. 6, and FIG. 9 is a cross-sectional view taken along the line ■-■ in FIG. 7.
FIG. 2 in the figure, (1) is the electrode, (2) is the external electrode, (3)
is tie bar, (301) is tie bar part, (4) is frame body, (5) is positioning hole, (6) is resin, (6A) is dam burr, (7] is dam burr stopper, (7a) Lt vertical part , (7b) is the horizontal part. 2. The same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) An electrode on which a semiconductor element is mounted, a plurality of external electrodes connected to the semiconductor element and led out, a tie bar that connects and supports each external electrode or each external electrode and the electrode; A lead frame for a semiconductor device comprising a tie bar and a frame supporting the electrodes and external electrodes and having positioning holes, etc., wherein the lead frame is connected to the tie bar portion facing the mold resin and is connected to the electrodes, external electrodes, and the frame. A lead frame for a semiconductor device, comprising dam burr stops having the same thickness and being separated, the dam burr stoppers preventing the occurrence of dam burrs in the direction of the tie bar during resin molding. . (2) For a semiconductor device according to claim 1, wherein the dam burr stopper is composed of a vertical portion connected to a tie bar and a horizontal portion connected in a T-shape to the tip of the vertical portion. Lead frame.