Pressure-assisted sinter bonding method at 300 °C in air using a resin-free paste containing 1.5 μm Cu@Ag particles

摘要

Pressure-assisted sinter bonding was conducted in air through in-situ Ag shells dewetting of 1.5 mu m Ag-coated Cu particles during die attachment for power devices. The effects on bonding when adding a solvent in the prepared paste were addressed. The dewetting-formed Ag nano-nodules induced faster Ag-Ag sintering. Furthermore, the bonding strength in the die was enhanced by the progress of out-diffused Cu-Cu sintering after dewetting. The reducibility of the solvent had a significant effect on the progress of Cu-Cu sintering. The bonding pressure and temperature were 5 MPa and 300 degrees C, respectively, and the resulting die exhibited an average shear strength of 22.7 MPa with a polyol-based solvent providing high reducibility.