Reliable SiC Discrete Package by Pressure-less Sintering: Die Attach Material Selection and Reliability Study

The rapid adoption of wide-bandgap materials such as silicon carbide (SiC) and gallium nitride (GaN) in high-power packages (e.g., TO series, and power modules) has significantly increased the demand for high-performance die-attach (DA) materials with superior thermal conductivity. Conventional soft solders with limited thermal conductivity are no longer sufficient to meet the requirements of high-performance power device application. In contrast, silver sintering, known for its ultra-high thermal conductivity, has emerged as a critical solution for power electronics. This work systematically evaluates the DA performance and device reliability using three pressure-less silver sintering pastes, one pressure-less copper paste and a traditional Sn-based solder for direct attachment on bare copper leadframes. It is found that proper material selection and packaging process control are critical for forming reliable die-to-leadframe interconnection on bare copper leadframe. Finally, a high-reliable TO-247 package, achieving automotive reliability requirements, for SiC MOSFET using pressure-less silver sintering was demonstrated.