Tuning the thermal and insulation properties of bismuth borate glass for SiC power electronics packaging

Abstract Silicon carbide (SiC) power devices are attracting significant attention due to their outstanding stability in high‐voltage, high‐temperature, and high‐frequency environments. To replace toxic Pb‐based glass, there is an urgent need to develop Pb‐free glass for SiC power device encapsulation, considering its superior electrical insulation properties and processing capabilities. Here, we developed a Bi‐based glass for effective encapsulation practical of SiC power devices. By increasing the content of glass modifier BaO, the structure of bismuth borate glass can be tuned to reduce glass network density, leading to the transition of structural units from [BO 4 ] to [BO 3 ]. The softened temperature is reduced to 363.4°C with the BaO content increasing to 15 mol%. After encapsulating the SiC power devices using Bi‐based glass, the glass demonstrated a reverse breakdown voltage of 650 V and an extremely low leakage current. Therefore, our work provided a route for adapting Pb‐free‐based low‐melting glass for encapsulating SiC devices and offered potential for advanced semiconductor packaging.