Thermal conductivity indicates that how fast the materials conduct heat, it has the unit of watt per meter kelvin. The table below summaries the thermal conductivity of different materials.
|Material||Thermal Conductivity (W/mK)|
|Copper Brass (Copper 70% + Zirconium 30%)||111|
|Copper Bronze (Copper 75% + Tin 25%)||26|
Copper alloy, aluminum and tin are the common interface materials between the LED package and heat sink in the LED lighting industry. Although diamond and silver have the relatively higher thermal conductivity (1000 and 406 W/mK respectively), the cost of using these material is very high, which makes the lamp cost become unreasonable. If someone told you that they have the “superconducting” material having 200,000 to 300,000 W/mK, or even higher, they deserve the Nobel Prize.