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The combination of excellent electrical conductivity and low cost makes copper a good selection for interconnect materials. However, rapid oxidation of Cu nanoparticles especially at high temperatures is a fatal demerit. To improve the oxidation resistance and realized mass production, Cu@Ag core-shell submicron particles were prepared using commercial copper oxide particles through a low temperature reduction method and subsequent electroless-plating to form Ag shells. Thermal analytical results suggest that Ag coated Cu particles show improved anti-oxidation ability. Mixed with Ag submicron particles obtained from thermal spray pyrolysis, the electrical resistivity of the sintered Cu-Ag composite pastes reaches 10.4 μΩ cm under a reductive atmosphere. Under the bonding pressure of 10 MPa at 275 °C for 30 min, robust Cu to Cu bonding can be achieved with the Cu-Ag composite pastes, for which the shear strength of the joints reaches 32.7 MPa, and it remains 28.2 MPa as the bonding pressure is reduced to 5 MPa. It was also demonstrated that the joints thus formed have superior elevated temperature strength, and excellent reliability subjected to high temperature storage at 250 °C as well as thermal cycling ranged from −65 °C to 150 °C. [ABSTRACT FROM AUTHOR]

A high-power packaging device composed of 600 V/450 A insulated gate bipolar transistor (IGBT) module is presented. Thermal dissipation is improved, and the temperature of junction declines after Ag paste sintering is applied instead of conventional soldering. A 100 μm-thick sintered Ag preform is utilized to assemble two IGBTs and two diodes on Al 2 O 3 direct bonded copper (DBC) substrate during reflow in a vacuum oven. Three DBCs are attached on a copper baseplate to construct a power module. After a thermal cycling test is conducted for up to 2000 cycles, the die shear strength of the sintered Ag is as high as 24.8 MPa. Lowering the induced stress to fracture failure by using finite element simulation is carefully suggested. Furthermore, the measured thermal resistance is reduced by approximately 22%, and the noise during the electrical performance is eliminated by using Ag sintering. This research reveals the successful application of Ag paste sintering in 600 V/450 A IGBT module. • A 600 V/450 A insulated gate bipolar transistor module is presented. • Thermal and electrical properties of silver paste sintering are measured. • Die shear strength of the sintered Ag is as high as 24.8 MPa is acquired. • Scaling diode and preform thicknesses has a good advantage in releasing thermal stress. • Lowering fracture failure is suggested using finite element simulation. [ABSTRACT FROM AUTHOR]