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1. Copper based composite:
L-Cop
Cu High thermal Conductive
Cu2O Low thermal expansive
Material Science

2. 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

3. L-Cop: powder-metallurgy
process
Electrolytic Cu powder & and CuO powder are used
Cu2O is thermally stable than CuO and in elevated temperature stable
phase of Cu & Cu2O can be readily achieved in sintering process due
to internal oxidation of Cu & CuO.
It is possible to distribute the Cu phase and Cu2O phase uniformly by
Cu + CuO Cu2O reaction Fabricated into preform
using a press
Ball Milling

4. Microstructure in Powder metallurgy process

5. Thermal Conductivity Vs. Coefficient of Thermal Expansion

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

7. Extruded L-Cop Vs. Sintered L-Cop

8. Extruded L-Cop application