Connection structure of intelligent power module terminal

Abstract

The invention relates to an intelligent power module terminal and a connection structure thereof. The terminal is of a step structure, and comprises a connection column which is vertically positioned, an upper bonding seat which is arranged on the lower part of the connection column, a lower bonding seat on the bottom, and a connection seat which is vertically positioned between the upper bonding seat and the lower bonding seat. The terminals are embedded on the periphery of a shell window at interval, the connection seats of the terminals are arranged in a shell, the lower bonding seats are fixed on a lower step surface of the window, the upper bonding seats are fixed on an upper step surface of the window, the connection columns penetrate out of the upper end face of the shell, a main circuit board is sealed and fixed on the bottom of the shell, the lower bonding seats of the terminals are bonded with the main circuit board through metal bonding wires, and the upper bonding seats of the terminals are bonded with a drive circuit board, which is arranged in the shell, through the metal bonding wires. The intelligent power module terminal and the connection structure thereof have the characteristics of reasonability in structure, small size, firmness in terminal bonding and improved working reliability.

Description

technical field [0001] The invention relates to an intelligent power module terminal and its connection structure, belonging to the technical field of power module manufacturing. Background technique [0002] Intelligent power modules (IPM for short) are widely used in AC motor frequency conversion speed regulation and DC motor chopper speed regulation and various high-performance power supplies, such as UPS, induction heating, electric welding machines, active compensation, DC-DC, etc., as well as industrial electrical automation And other fields, has a broad market. The traditional intelligent power semiconductor module mainly includes the casing, the main circuit board and the driving circuit board, semiconductor chips and other devices and multiple terminals welded on the metal-ceramic substrate to form the main circuit board, and the printed circuit board with the integrated circuit chip and various devices welded The drive circuit board constitutes the drive circuit b...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the terminals on the power module are sintered on the metal layer of the cermet-clad substrate by solder at high temperature. The terminals include electrode terminals and signal terminals. The welding stress is generated at the place, and the working environment of the intelligent power module is cycled at -40°C to 125°C, so after a period of work, the metal layer of the metal-ceramic substrate and the terminal connection will eventually fall off, resulting in welding fatigue phenomenon, thus affecting the life of the overall power device

Secondly, the terminals are welded on the metal layer of the cermet-clad substrate with solder, which not only has high requirements on the surface of the metal layer of the cermet-clad substrate and the surface of the terminal, especially the metal layer of the cermet-clad substrate, that is, the copper foil and the copper material of the electrode terminal. There will also be a difference in thermal expansion between them, and the welding performance is not high, which will affect the electrical conductivity

At the same time, the welding process not only requires solder, flux and protective gas during welding, not only the high-temperature sintering welding process takes a long time, but also the high temperature generated can easily lead to weakening of the metal properties of other parts of the material, and the solder flow and solder resistance during the welding process Factors such as ink will cause the risk of contamination on the welding surface. The existing terminal welding has the problems of difficult control of the welding surface, complicated process operation, and low welding efficiency.

Furthermore, the electrode terminal needs to be bent, but the bending strength and angle of the electrode terminal are not easy to control, which makes the bending process more demanding. On the one hand, the electrode terminal will also have cracks at the bend. and cause the problem of increased local resistance

On the other hand, it is not easy for multiple electrode terminals after bending to be at the same height, and it will also cause excessive contact resistance caused by poor contact between the drive circuit board and the terminals, which will cause local overheating and affect the firmness of the terminal connection. sex

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