Copper based composite: L-Cop Cu High thermal Conductive Cu 2 O Low thermal expansive Anna malai Industrial Engineering Material Science

Introduction Application Electronic devices to achieve long life and reliable performance High current power modules To reduce high shear stress at soldering joint Mismatch in coefficient of thermal expansion between ceramic substrate to Cu/Al base plate attachment Silicon carbide reinforced aluminum SiC/Al Difficult to machine due to high ceramic content Cu/Mo & Cu/W Composite Difficult to manufacture – Sintering at above 2000°C

L-Cop: powder-metallurgy process Electrolytic Cu powder & and CuO powder are used Cu 2 O is thermally stable than CuO and in elevated temperature stable phase of Cu & Cu 2 O can be readily achieved in sintering process due to internal oxidation of Cu & CuO. It is possible to distribute the Cu phase and Cu 2 O phase uniformly by Cu + CuO Cu 2 O reaction Fabricated into preform using a press Ball Milling

Microstructure in Powder metallurgy process

Thermal Conductivity Vs. Coefficient of Thermal Expansion

Hot Extrusion Process 6500 Mpa Cold Isostatic press Subsequent hot extrusion. Improves Heat conductivity, Coefficient of thermal expansion & Density

Extruded L-Cop Vs. Sintered L-Cop

Extruded L-Cop application

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