Ceramic-copper substrate technology introduction

Ceramic-copper substrate is used to achieve the combination between copper and ceramic (Al₂O₃ or AlN) under high temperatures by bonding or brazing process, then through dedicate lamination – etching technology to develop the designed layout in copper surface, finally parts go with plating and singulation process for surface treatment before shipping to the end-user. Ceramic-copper substrate has perfect performance in terms of insulation, thermal conductivity, solderability, and adhesion strength. Besides, the copper on surface can afford huge current due to the fact that ceramic has good reliability and thermal-cycling performance. According to technical visit and audit to suppliers’ manufacturing process and based on several years’ experience of mass production for electric vehicle power module package, this article introduces two mainstream ceramic-copper substrate processing methods currently on the market: direct bond copper (DBC) and active metal brazing (AMB) which can be widely used for the intelligent power module and electric vehicle power module, also introduces the major failure mode during application and analyzes the root cause for each failure mode, clarifies key incoming monitoring method, like crosshatch, silver plating thickness measurement and blister test. This article also clarifies the Incoming Quality Control system, which can provide guidance to process engineer during the application.