超声波清洗引入的芯片金属化裂纹机理分析

对某塑封器件进行破坏性物理分析(DPA),发现芯片表面存在玻璃钝化层裂纹和金属化层划伤的缺陷。对缺陷部位进行扫描电子显微镜(SEM)检查和能谱(EDS)分析,通过形貌和成分判断其形成原因为开封后的超声波清洗过程中,超声波振荡导致环氧塑封料中的二氧化硅填充颗粒碰撞挤压芯片表面,从而产生裂纹。最后,进行了相关的验证试验。研究结论对塑封器件的开封方法提出了改进措施,对塑封器件的DPA检测及失效分析(FA)有一定借鉴意义。

Mechanism analysis for die crack of plastic encapsulated microcircuits caused by ultrasonic cleaning

The destructive physics analysis(DPA) was performed on a batch of the plastic encapsulated microcircuits. Some glass passivation layer cracks and metal layer scratches were found on the surface of the chip. Scanning electron microscope(SEM) and energy disperse spectroscopy were used to analyze the surface defects. It was determined that the cause of the defects and cracks was that during the ultrasonic cleaning process after unsealing, the ultrasonic oscillation caused the silica filled particles in the epoxy molding compounds to collide and compress the surface of the chip. Finally, the relevant verification tests were carried out. The research conclusions put forward the improvement measures for the unsealing method of plastic encapsulated microcircuits. Experiences are accumulated for the DPA and failure analysis of the plastic encapsulated microcircuits.