Research on PCT Reliability of Power Devices based on FOPLP

Fan-Out Panel Level Package (FOPLP) is a newly developed package scheme, which has high packaging efficiency, low internal resistance and high heat dissipation. In the development process of package scheme, the air-tightness of package is a key research object. At present, the research on air-tightness mainly focuses on traditional wire bond (WB) and clip welding, but there is little research on the new FOPLP package scheme. Therefore, the air-tightness of the FOPLP package scheme for the Pressure Cook Test (PCT) was studied in this paper. Through the measurement of CTE of Epoxy molding compound (EMC) before and after PCT, it was found that wet stress plays a major role in the process of PCT; however, through the analysis of electrical performance parameters and C-SAM image, it was found that the stress does not have a significant impact on the air-tightness of the package. Additionally, the mechanism of moisture diffusion of EMC after moisture absorption was studied and tested by two kinds of EMC with different moisture absorption rates, it was found that the corrosion of the package chip is directly related to the moisture absorption rate of the EMC, which provides a theoretical reference to the selecting of the EMC for the package in the future.