Reliability study of large-area sintered Cu for power electronic packaging

Purpose This study aims to investigate the fracture behavior and reliability of large-area sintered Cu for power electronic packaging, with a specific focus on the influence of the “edge effect” on interfacial performance and structural deformation. Design/methodology/approach By fabricating sintered Cu joints with different dimensions (8 × 8 mm2, 16 × 16 mm2 and 32 × 32 mm2) and evaluating their microstructures, mechanical properties and warpage behavior, the mechanism of nonuniform performance degradation induced by the “edge effect” is revealed. Findings As bonding area increases from 8 × 8 mm2 to 32 × 32 mm2, shear strength drops from 105.18 MPa to 61.36 MPa, while edge porosity rises from 13.92% to 28.87%. High-temperature storage and thermal cycling (TC) exacerbate void expansion, with edge porosity reaching 37.73% after TC. Simulation reveals that stress induced by coefficient of thermal expansion mismatch increases nonlinearly with area, correlating with strength degradation zones. Experimental warpage matches simulation results within 6% error. Originality/value This study provides a crucial experimental basis and theoretical support for the process optimization and reliability design of large-area sintered Cu.