Research on TSV Stress of Ultra-thin Optical Fingerprint Chip

With the rapid development of consumer electronics and other industries, the packaging of ultra-thin optical fingerprint chips is constantly developing towards smaller packages. TSV is an effective means to realize ultra-thin fingerprint chip packaging. In order to solve the phenomenon of the stress of TSV of the existing ultra-thin optical fingerprint chip which has led to the delamination of copper and polyamide (PA) after temperature cycling (TC) in the existing package, this paper adopts the method of finite element simulation to establish two models of slope metal-free and metal interconnection. Through the simulation results, it can be found that the metal interconnection structure can make the PA in a state of uniform stress distribution at the bottom of the groove; for the model structure without metal on the slope, the metal and the upper surface of the PA will not form stress locations, but compared with the original model, it increases about 25.7% the stress of PA at the bottom corner of the groove, so it is easy to cause the fracture of PA.