Ceramic Capacitors Attached with Sac Solder
Failure avoidance in ceramic chip capacitors has been accomplished through the development of design guidelines based on physics of failure principles. The transition to Pb-free solder, specifically SnAgCu, has resulted in both a change in processes and materials. This has required a review of current guidelines and modifications where appropriate.
Failure mechanisms for ceramic capacitors are presented and the drivers for failure occurrence, mechanical, thermal, chemical, and electrical, are tabulated. The influence of Pb-free solder on each driver is then analyzed, with the subsequent output changes in current design guidelines with justification when appropriate.