Development of Cu-Cu Joining Technology by Laser Welding

More and more applications require higher power density, reliability and efficiency, but also lower costs. To meet this demand, power semiconductors made of Silicon Carbide (SiC) as well as Gallium Nitride (GaN) are already in use. However, these advanced applications are limited not only by the performance of the semiconductor devices, but also by the packaging materials and interconnect technologies.

Laser welding technology has been established as a highly productive bonding technology, providing strong and reliable interconnects. Therefore, this study investigates the substitution of soldering technology and ultrasonic welding technology with laser welding of Cu connections.

This whitepaper contains:

• Reasons behind growing market demand for new technologies for Cu-Cu joints in power semiconductor packages.
• Benefits of using laser welding to join copper (Cu) leads to direct copper bonded (DCB) substrates.
• Overview of laser welding technology as a substitute for soldering technology to achieve strong and reliable joints.
• Optimization of the laser welding process using various evaluation methods such as optical inspection, shear strength measurement, analysis of micrograph sections, isolation check, and electrical characteristics.