Die-bonding performance and mechanism based on the sintering of micro Ag paste for high power devices

Commercially available micron-sized Ag flake particles and submicron-sized Ag particles were used to make Ag paste. The Ag paste was used to connect Si dies to Ni-Ag plated Cu substrates to achieve die-bonding joint for high temperature application. The contact between die and Ag paste was affected by the loading pressure, and was realized with only 0.2 MPa pressure. And the shear strength depended on the bonding pressure and increased over 20 MPa with only 0.2 MPa pressure. The high shear strength achieved at low bonding pressure contributed to the tight contact between die and paste, and optimized bonding pressure.