JPH11145342A - Power semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adhesivity of a resin mold to a power semiconductor device. SOLUTION: This device is constituted of a metal base 1, a power semiconductor chip 4, an input/output terminal 5 and a resin mold 3 prepared through injection mold method. A tapered hole, wherein a diameter of the metal base 1 at the side in which the resin mold 3 is formed is small, and a large diameter at an opposite side of the side where the resin mold 3 is formed is provided. Thereby, the peel off between a base and a resin mold of a power semiconductor device can be eliminated, thus improving productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the adhesion of a resin mold to a metal base of a power semiconductor device.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional power semiconductor device includes a metal base 21, a power semiconductor chip 24, input / output terminals 25, and a resin mold 23. The metal base 21 is provided with a screw hole for screw mounting in a region where the resin mold 23 is formed, and a screw 22 several millimeters longer than the thickness of the metal base 21 is inserted into the screw hole, and the resin mold is formed by a metal injection method. Is done. The resin molding material injected by the injection method is filled around the screw thread of the screw 22 and hardened, and the metal base 21 and the resin mold 23 are firmly fixed to prevent the resin mold 23 from being separated from the metal base 21. You.

[0003]

However, in the prior art, a screw 22 is fixed to a metal base 21 and the screw 22
The resin mold and the metal base are stopped together to prevent the metal base and the resin mold from peeling off.
This requires time and effort to mount the power semiconductor device, which is a factor that reduces the productivity of the power semiconductor device.

[0004]

A power semiconductor device according to the present invention comprises a power semiconductor chip, a metal base on which the power semiconductor chip is mounted, an input / output terminal connected to the power semiconductor chip, and an injection or transfer device. And a resin mold for protecting the power semiconductor chip, wherein the diameter of the metal base on the side where the resin mold is formed is the same as that of the resin mold. Has at least one tapered hole that is smaller than the diameter on the side opposite to the side on which is formed. By forming a tapered hole in the metal base, a part of the resin material of the resin mold is cut into the tapered hole of the metal base when the resin material is filled, thereby preventing the resin mold from peeling off the metal base.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIG. 1 showing an embodiment thereof. The power semiconductor device includes a metal base 1, a power semiconductor chip 4, input / output terminals 5, and a resin mold 3 manufactured by injection molding.
It is composed of

[0006] The metal base 1 is provided with at least one hole 2 having a tapered shape. Hole 2 with taper
Is a tapered hole having a small diameter on the side of the metal base 1 where the resin mold 3 is formed and a large diameter on the side opposite to the side where the resin mold 3 is formed.

When forming a mold by the injection molding method, a mold for the mold 3 is manufactured, and a liquid resin molding material is injected onto the metal base 2 while applying pressure. The resin molding material is simultaneously injected into the tapered hole 2 by the applied pressure. The liquid resin molding material injected into the tapered hole 2 cures in the tapered hole 2 and fixes the resin mold 3 to the metal base 1. Hole 2 with taper
Since the diameter of the metal base 1 on the side where the power semiconductor chip 4 is mounted is small and the diameter of the tapered hole 2 on the opposite side of the metal base is large, the diameter of the tapered hole 2 is smaller than that of the power semiconductor chip 4 mounting side. Due to the difference on the opposite side, when the resin mold material is injected into the tapered hole 2, the resin mold 3 becomes difficult to separate from the metal base 1.

In the above-described embodiment, the power semiconductor device is described by the injection molding method. However, the power semiconductor device may be performed by general transfer molding.

[0009]

By providing a tapered hole in the metal base, peeling between the base of the power semiconductor device and the resin mold can be eliminated, and the productivity can be improved.
Also, there is no need to drill screw holes for screws in the metal base, and there is no need to attach screws.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an embodiment of a power semiconductor device of the present invention.

FIG. 2 is a structural diagram of a conventional power semiconductor device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 metal base 2 tapered hole 3,23 resin mold 4,24 power semiconductor chip 5,25 input / output terminal 21 metal base 22 screw

Claims (1)

[Claims] 1. A power semiconductor device having a power semiconductor chip, a metal base on which the power semiconductor chip is mounted, input / output terminals connected to the power semiconductor chip, and a resin mold for protecting the power semiconductor chip. And at least one taper at a portion of the metal base where the resin mold is formed, the diameter of the side where the resin mold is formed is smaller than the diameter of the side opposite to the side where the resin mold is formed. A power semiconductor device having a perforated hole.