Analysis and Root and Cause Investigation on Non-Wet Defect between Solder Bump and PCB

초록

In this study, the root cause of non-wet defect between the solder bump and printed circuit board (PCB) was investigated through five step traceback analysis. It was identified that unknown particles with a size of ca. 500?nm were the primary cause of the non-wet defects. To investigate the formation mechanism, a step-by-step review of the PCB manufacturing process is conducted. Traceback analysis demonstrates that PGMEA cleaning solvent can form spherical emulsions when mixed with deionized (DI) water during the cleaning process. Thus, organic nanoparticles grow in the PGMEA emulsion on the Cu pad during OSP application for surface finishing purposes. These results confirm the importance of optimizing the PCB cleaning process to prevent unknown nanoparticle formation, ensuring improved reliability in semiconductor packaging applications. -본 연구는 2025년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(No. 2022R1A6A1A03051705). Keywords: Non-wet defect, Traceback method, OSP, Unidentified particles, Emulsion.