Bonding microwave absorbing ferrites to thermal conducting copper

In the present study, the thermal characteristics of spinel ferrites are reported. The thermal expansion coefficient of ferrites is slightly larger than that of silicon; furthermore, these ferrites all demonstrate capability to absorb microwave. Nevertheless, their thermal conductivity is relatively low. A copper plate is bonded to ferrite to provide a backing for heat spreading. Microstructure observation at the interface reveals no reaction phase. The thermal resistance at the copper-ferrite interface is low. With the bonding of metallic copper, the heat generated in ferrites by microwave absorbing is possible to be removed by the backing copper layer.

Automated summary

The study found that spinel ferrites have a larger thermal expansion coefficient and microwave absorbing capability, but relatively low thermal conductivity. Bonding with a copper plate can provide heat conduction support, and a low thermal resistance at the copper-ferrite interface was observed.