基于COB组装工艺的芯片失效分析

在市场上逐步推广的液晶模块(LCM)生产中,其LCD系列驱动电路的封装工艺主要采用裸芯片的COB(chip on Board)封装方式。文中通过总结自行设计和加工的LCD系列电路在应用厂商批量使用过程中出现的COB封装问题,对COB的工艺流程、COB工艺中的关键工艺——键合以及主要的失效点以及常见的失效原因进行分析,并结合在实际推广过程中问题的解决方法,对LCD系列驱动电路和其他芯片在COB应用中主要出现的键合不良、边缘铝层颜色异常、钝化孔残留、键合参数、COB环境等方面问题加以整理归纳,并提出了可行的解决办法。

Chip Defect Analysis Based on COB Assembly Process

In mass production of LCD module under widely developed market,the assembly process of LCD drive circuits is based on COB(Chip on Board)technique.This article conclude the COB assembly prob- lems of LCD series circuits which designed and fabricated by our company in the course of custom's application. We analysis the COB process,the key process-bond process,main defect phenomenon and common defect cause.Combined with the practical solution,we summarize the main defect problems of LCD drive circuits and other chips in COB application such as abnormal bond,abnormal colour on verge of aluminium,residual in passivation via,bond parameter and COB environment etc,and put forward more effective solution.