Development of Cu-Cu Joining Technology by Laser Welding for Terminal Attach within Power Semiconductor Package

Inhalt:
This paper presents the results of laser welding which connect the copper terminal to the Direct Copper Bonded (DCB) substrate within the power semiconductor discrete package. The laser welding process was optimized using various evaluation methods such as optical inspection, shear strength measurement, analysis of micrograph sections, isolation check and electrical characteristics. Shear strength values are 50% higher than current technology and repeatedly achieved for all units. The thermal cycling of units is exceeded far more than expectation with no failure. Reliability tests are still on-going to end of life failure. This contribution compares the laser welding technology results with the conventional soldering technology. The results of this study are going to be used for further development of terminal to the substrate attach for power semiconductor module packages.