Analysis And Improvement For DIP Low Voltage Smart Power Module Packaging Defects

The low voltage Smart Power Module is developing rapidly in industrial and consumer field. The supplier of SPM must improve the manufacturing process stability, yield and reliability as well as must reduce the cost to meet the marketing requirement. The purpose of the paper is to improve the major defects happened during SPM packaging process: solder void in die mounting & reflow process and incomplete fill in molding process. These two defects were analyzed and the process parameters optimized after DOE (Design of Experiment). Two significant factors: the reflow temperature profile and the EMC (Epoxy Molding Compound) transfer parameter were indicated and optimized after DOE. The improvement action items were also concluded after mechanism analysis for process failures. The study concluded that the solder void defects is the major reason of the die crack, the void caused by the entrapped flux and oxide outgassing issue. Optimization for reflow temperature profile can improve the outgassing and reduce the solder void defects;The incomplete fill defect is the major reason of SPM module isolation and reliability test failure. The improper flowability of EMC caused incomplete fill. The best flowability can be achieved by optimization for EMC transfer pressure, transfer time and molding temperature. The incomplete fill defects can be reduced consequently. The quality of process is improved significantly under the optimized Packaging process condition.