功率VDMOS器件粗铝丝键合工艺研究

摘要

The heavy Aluminum wire bonding is the key process in the flow of the power VDMOS devices packaging. It is very important to have a bonding quality which will affect the finished product yield and the screening yield. The process of wire bonding with 380 µm heavy Aluminum was studied on power VDMOS devices. Results show that the pad width should be larger to 150 µm in order to improve the bonding quality when the second bonding angle was 130°. Moreover, the bonding damage was less with the second bonding angle decreasing. The pad minimum width is 1 800 µm for the non-damaged bonding point with the default second bonding angle.%粗铝丝键合是功率VDMOS器件封装的关键工序，键合质量的好坏直接影响到器件的封装成品率以及后续的筛选成品率。针对直径为380μm的粗铝丝进行功率VDMOS器件的键合工艺研究。结果显示，在选取130°的键合角度时，焊盘宽度应适当增加且应至少增加150μm，才能保证键合质量；随着第二点键合角度的增加，键合点尾丝端划伤芯片的情况变好；同时考虑键合点尾端和键合点颈部都完全在焊盘内，且采用默认的第二点键合角度，则所需焊盘宽度至少应为1800μm。