Packaging shell structure for semiconductor power module

Abstract

The invention relates to a packaging shell structure for a semiconductor power module. At least four electrodes are embedded on the two sides of a shell respectively; aluminum wire bonding seats of all the electrodes are arranged on a base on the inner side of a wall plate; connecting seats are arranged on all electrode seats on the outer side of the wall plate; connecting pieces with internal threads are respectively inserted into slots of all the electrode seats and are connected with the connecting seats of the electrodes; limiting bumps for limiting the connecting pieces are arranged on the end parts of elastic arms on the two sides of the slots of the electrode seats; at least four signal terminals are embedded in the wall plate of the shell; the aluminum wire bonding seats of all the signal terminals are arranged on the base on the inner side of the wall plate; the other side of each signal terminal passes through the upper end face of the shell wall plate; a cover plate is arranged at a seam of the shell wall plate and is clamped on the inner wall of the shell wall plate; the shell is positioned on the outer side of the wall plate and is provided with at least two mounting seats; and T-shaped bushings are pressed on the mounting seats and a bottom plate. The structure is reasonable, the bonding fastness of all the electrodes and all the signal terminals is effectively improved, external copper bars are reliably arranged, and the structure is convenient to assemble.

Description

technical field [0001] The invention relates to a package shell structure of a semiconductor power module, which belongs to the technical field of semiconductor power module manufacturing. Background technique [0002] Semiconductor power modules are widely used in industrial control such as electric transmission and motor control, automobile drive and hybrid power, wind energy, welding machine, locomotive traction and many other fields, to convert the input direct current (DC) into three-phase alternating current (AC) output, as Various switching power supplies. The traditional power module is mainly composed of a semiconductor chip, a metal-ceramic substrate (DBC), a copper base plate, a housing, a cover plate, etc. The semiconductor chip and electrodes are welded on the metal-ceramic substrate or base plate, and the bottom of the metal-ceramic substrate is fixed. On the copper base plate, the semiconductor chip and the metal-ceramic substrate are sealed and fixed in the ...

AI Technical Summary

Problems solved by technology

Since the electrodes on the semiconductor power module and one end of each terminal are fixed on the metal-ceramic substrate, each electrode and each terminal pass through the casing and the end cover to realize electrical connection with the outside. The electrodes and signal terminals are fixed, so the electrodes and signal terminals are easy to shake. During the long-term operation of the semiconductor power module, the electrodes and terminals of the semiconductor chip will be subjected to mechanical vibration, mechanical stress and thermal stress, etc. Influenced by various factors, and some semiconductor power modules work in a vibration environment, various stresses and vibration forces will cause the electrodes and signal terminals to vibrate and spread to the bonding places, thereby reducing the vibration of each terminal and each electrode. The firmness of the bonding point, resulting in power loss due to shaking

Secondly, since each electrode needs to be bent and placed on the electrode holder, and the installation requirements for the external copper bars are relatively high, otherwise it is easy to damage the firmness of the electrode bonding during the installation process

Furthermore, because the electrode is connected to the copper bar after being bent at the end, the installation surface of the electrode cannot be completely flat. After the copper bar is installed, it is easy to make poor contact with the electrode and cause excessive contact resistance, which in turn causes local overheating. It will also affect the firmness of the electrode connections

In the currently disclosed semiconductor power modules, the casing and the bottom plate are connected by fasteners, and the end cover is fixed on the casing. Not only the structure is complicated, but also the assembly process is complicated, and the installation efficiency is not high.

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