Tungsten Copper Heat Sink Electrical Conductivity (1/2)

Except Rockwell hardness (HRB) of detection, it is essential that electrical conductivity measuring in tungsten copper composite materials as heat sink materials. Electrical conductivity is an important indicator to measure ability to conduct electricity of tungsten copper heat sink, which directly affects the final properties of products. The stronger ability to conduct electricity, the smaller electrical resistance, on the contrary, electrical resistance is greater. For hardness testing, if tungsten copper material over-burning, the inside Cu phase will exude and lead to the emergence of the hole, making the overall decrease in hardness; while the precipitation of Cu phase of segregation occurred, and thus will make the hardness not dropped significantly. Based on the theory, the relevant researchers have concluded that the most likely two factors tungsten copper electrical conductivity of heat sink, one is copper content, the other is the porosity.

Theoretically, tungsten copper composite material is composed of tungsten (W) and copper (Cu). W phase has higher hardness and melting point, lower electrical conductivity; on the contrary, Cu has lower hardness and melting point, but it has excellent electrical conductivity. Therefore, it can be speculate that electrical conductivity of tungsten copper heat sink material depends on how much copper content, the higher the copper content, the corresponding tungsten-copper composite conductivity is higher. From chemical energy band, different metal has different equivalent orbital and atom distance, which band (or empty) overlap, constitutes a full conduction band, and easily to have a metallic conductivity. So as long as there is not full of the conduction band, whether it itself is not full band, or the empty band and full band formed by overlapping unfilled band, under the action of external electric field will form a directional flow of electrons, thereby such that the material has conductivity.