Method for reducing overflow in injection molding of IPM (Intelligent Power Module) and DBC substrate

Abstract

The invention discloses a method for reducing overflow in injection molding of an IPM (Intelligent Power Module) and a DBC substrate. The method changes an island design on the DBC substrate and enables the DBC substrate to be balanced in stress in the injection molding process. In addition, a wedge-shaped table structure is designed on a DBC back copper layer at the back of the DBC substrate, a buffer table for the flow rate of an injection molding material at the back of the DBC substrate is formed, and the injection molding material overflowed towards the back of the DBC substrate is reduced under a condition that the DBC substrate is uneven. According to the invention, the method of reducing the overflow through changing the DBC design idea is adopted to replace a laser burr removing process, the production efficiency is improved, and the production cost and technological input are reduced.

Description

technical field [0001] The invention belongs to the technical field of IGBT chips and relates to injection molding of IPM modules, in particular to a method for reducing injection molding overflow of IPM modules and a DBC substrate. Background technique [0002] Intelligent power module IPM (Intelligent Power Module) is a new type of control module that integrates IGBT chip and its drive circuit, control circuit and overcurrent, undervoltage, short circuit, overheating and other protection circuits. It is a complex and advanced power module that can automatically realize complex protection functions such as overcurrent, undervoltage, short circuit and overheating, so it has intelligent features. At the same time, it has the advantages of low cost, miniaturization, high reliability, and easy use, and is widely used in frequency conversion household appliances, servo motors, industrial frequency conversion and other fields. [0003] The plastic-encapsulated IPM module will ad...

AI Technical Summary

Problems solved by technology

When each module is injected, the fixed positioning of the DBC is mainly achieved by the pressure exerted by the top of the upper mold on the two islands of the DBC. The pressure on the DBC is mainly concentrated at the far end of the PCB, so it often occurs that the DBC is close to the PCB. Flashing occurs, which not only affects the appearance quality of the module, but also greatly reduces the heat dissipation function of the module due to the reduction of the heat dissipation area, and reduces the reliability of the module

At present, the problem of flashing can only be improved by laser deburring process

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