基于湿气分层扩散理论塑封集成电路失效案例研究OA

Layered failure is one of the core failure modes of Plastic Encapsulated Integrated Circuits(PEIC).Based on the theory of moisture stratified diffusion,this study systematically analyzed the intrinsic coupling mechanism between moisture and stratification phenomena,while also examining the transfer laws of heat and thermal stress during the PEIC stratification process.This profoundly revealed the principle behind the"popcorn"phenomenon of PEIC.Based on theoretical analysis,this paper conducts in-depth research on typical failed transformer samples.Through I-V electrical characteristic tests,X-ray examinations,acoustic scans,X-CT slice analyses,and elemental spectroscopy detections on the failed transformers,it was confirmed that the adhesion between the soft gel and the encapsulation material of the failed samples had failed.Heat continuously flows into the interlayer area between the two,and in the high-temperature and high-humidity conditions,bubbles are generated between the bonding layers.As the bubbles continue to accumulate,macroscopic layering occurs,which is known as the"popcorn"phenomenon.Ultimately,this study focused on optimizing the performance of the encapsulation material(selecting highly stable encapsulation materials),improving the encapsulation process and curing parameters(adopting a stepped pressure increase strategy combined with a three-level vacuum exhaust method and using the"stepwise heating method"for the curing process),and designing a reasonable structure(using CTE difference gradient materials and rounding the edges of the substrate).These targeted improvement measures provide theoretical support and technical guidance for the research and manufacturing processes of high-reliability PEIC.