Interfacial microstructures and thermal/electrical conductivity of high‐temperature co‐fired alumina ceramic substrates

Abstract The thermal, electrical, and mechanical properties of the metal–ceramic interface in ceramic substrates are now critical in the performance and reliability of electronic equipments. This study systematically investigated the interfacial properties between platinum and alumina in HTCC substrates. Results revealed that a high interfacial bonding strength of approximately 1 GPa was achieved between platinum and alumina, which was attributed to minimized thermal stress, reduced interface defects due to the incorporation of ultrafine alumina powders in the platinum paste, and the closely matched thermal expansion coefficients of Pt and Al ₂ O ₃ . Meanwhile, the thermal conductivity was 98.33 W/m·K at 25°C, and the electrical conductivity was 1.67 × 10 ⁷ S/m at 20°C. As a result, high‐temperature Co‐fired ceramics substrates with strong interfacial bonding between platinum and alumina, coupled with excellent thermal and electrical properties, are promising materials for advanced electronic packaging.