Reliability and thermal structure design for CMOS image sensor

The characteristic of overall structure for CMOS image sensor has been studied in this paper. This paper demonstrates the thermal design for the material of compound, UV glue as well as glass. A three-dimensional solid model of CMOS image sensor based on finite element ANSYS software is developed to predict the thermal strain distributions. It is found that the peak stress in UV glue plays a significant role through the manufacturing process. The predicted thermal strains were based on previous researches with the Moire interferometry experimental scheme. The developed finite element 3D model is compared with the JEDEC standard JESD22-A104 reliability thermal cycle test (TCT). The failure mode trend for both predicted model and TCT experimental result were found to be good agreement. A series of comprehensive parametric studies were conducted in this paper. The design rules for thermal optimization of CMOS image sensor are summarized