JPH05226552A - Lead frame for resin sealed semiconductor device - Google Patents

Abstract

PURPOSE:To suppress the generation of dam burrs or thin burrs caused by resin on the outside of resin during molding. CONSTITUTION:A polyimide tape 7 with high thermal resistance and flexibility is formed on an inner lead 2 side of mold resin line 9 in a lead frame, and when it is pressed down by a molding die 6 during resin molding, a resin 1 is prevented from exuding, thereby simplifying the following processes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-encapsulated semiconductor device lead frame.

[0002]

2. Description of the Related Art Conventionally, when a resin-sealed semiconductor device is manufactured, a semiconductor element is die-bonded to a die pad of a lead frame, and these are resin-sealed with a molding resin. A diver is provided in the middle of the outer lead of the lead frame in order to eliminate leakage of the resin when forming the sealing resin, that is, the mold.

FIGS. 4A and 4B are a top view and a sectional view showing a conventional lead frame for a semiconductor device of this type. In FIG. 4, 1 is a resin-sealed mold resin,
Reference numeral 2 is an inner lead of the lead frame, 3 is also an outer lead, 4 is a tie bar provided in the middle of the outer lead 3, 5 is a dam burr dammed by the tie bar 4, 6 is a molding die for resin sealing, and 8 is a mold die. Is a thin burr formed by the resin exuding from a slight gap between the molding die 6 and the lead frame, and 9 is a molding resin line (meaning a boundary where the leads are exposed from the molding resin 1 to the outside). is there. As shown in FIG. 4, the outer lead 3
A tie bar 4 is provided in the middle of the process, and the lead frame is pressed down by the mold die 6, so that when the molten resin is injected into the mold die 6, the tie bar 4 dams it and forms a resin-sealed semiconductor package. To be done. At this time, there is a slight gap between the pressed mold 6 and the lead frame, and thin burrs 8 and dam burrs 5 are formed on the upper surface of the lead outside the mold resin line 9 due to resin bleeding. .

[0004]

In the conventional lead frame as described above, the dam burr 5 dammed by the tie bar 4 is removed (deburring) and the thin burr 8 exuding on the surface of the outer lead 3 is removed (deburring). ) Is required, and finally the tie bar 4 in the middle of the outer lead 3 needs to be removed (tie bar cut). As described above, there is a problem that many steps (treatments) are required after the resin sealing.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a lead frame for a semiconductor device in which the processing steps after resin molding are simplified.

[0006]

In a lead frame for a semiconductor device according to the present invention, an insulating film for preventing exudation of mold resin is provided on the inner lead side or outer lead side of the mold resin line or on the mold resin line. It is a thing.

[0007]

In the lead frame of the present invention, the heat resistant and flexible insulator is formed on the inner lead side or the outer lead side of the mold resin line or on the mold resin line. When applied, the melted resin is dammed by the insulator, preventing thin burrs and dam burrs from occurring.

[0008]

The present invention will be described below. Figure 1
(A), (b) is the top view and sectional drawing of the principal part of the lead frame which shows one Example of this invention. This example
An insulating film having heat resistance and excellent flexibility, for example, a polyimide tape 7 is provided on the inner lead 2 side of the molding resin line 9, and the molding resin 1 is dammed by the polyimide tape 7.

The same effect can be obtained when a silicone resin is provided instead of the polyimide tape 7 of the above embodiment. At this time, the silicone resin may be obtained by solidifying a silicone adhesive.

FIGS. 2A and 2B are views showing another embodiment of the present invention, in which the same polyimide tape 7 as that shown in FIG.
Are stopped by the polyimide tape 7 on the mold boundary.

In the embodiment shown in FIG. 2, the same effect can be obtained when the polyimide tape 7 is replaced with a silicone resin.

FIGS. 3 (a) and 3 (b) are views showing still another embodiment of the present invention. A polyimide tape 7 similar to the embodiment of FIGS. 1 and 2 is provided on the outer lead 3 side from the mold resin line 9. Provided, the mold resin 1 is the mold resin 1
It is stopped by the polyimide tape 7 on the outside. At this time, since this polyimide tape 7 is an insulator, it need not be removed. In the embodiment of FIG. 3, the same effect can be obtained when the polyimide tape 7 is replaced with a silicone resin.

[0013]

As described above, according to the present invention,
Prevents exudation of mold resin without forming a tie bar by providing a heat-resistant and highly flexible insulating film on the inner lead side or outer lead side of the mold resin line of the lead frame or on the mold resin line it can. Therefore, it is possible to eliminate the generation of dam burrs and thin burrs as in the conventional example, and it is possible to omit the removal process (treatment) thereof.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a lead frame for a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a main part of a lead frame for a semiconductor device according to another embodiment of the present invention.

FIG. 3 is a diagram showing a main part of a lead frame for a semiconductor device according to still another embodiment of the present invention.

FIG. 4 is a diagram showing a main part of a conventional lead frame for a semiconductor device.

[Explanation of symbols]

 1 Mold Resin 2 Inner Lead 3 Outer Lead 6 Mold Die 7 Polyimide Tape 8 Thin Burr 9 Mold Resin Line

Claims (1)

[Claims] 1. In a resin-encapsulated semiconductor device lead frame, an insulating film is provided on the inner lead side, the outer lead side, or the mold resin line of the mold resin line at the boundary where the leads are exposed to the outside from the mold resin. A lead frame for a resin-sealed semiconductor device, which is characterized by: