Pressureless Large-Area (15 × 15 mm2) Bonding by Novel Silver Paste for WBG Packaging

Among the most effective die-attach materials for achieving wide-bandgap (WBG) device performance in harsh environments is sintered silver. However, organic residues and low shear strength largely limit the practical application of sintered silver in large-area interconnections. In this paper, by proposing a novel silver paste, robust large-area (15 × 15 mm
²
) interconnections are achieved at pressureless and 300 °C sintering temperature in air atmosphere. The relationship between the shear strength and microstructural changes in the areal distribution in large-area interconnections is studied in detail. The shear strength distribution law in large-area interconnections is studied in detail. The average shear strength of the bonding joint is 29.6 MPa, the edge shear strength is the lowest at 25.4 MPa, and the shear strength distribution is uniform. The development of novel silver paste has successfully solved the problems of low shear strength in large-area sintering, and greatly promoted the practical application of high-power density dies.