Ceramic heat plates are flat boards that are shaped and go behind a printed circuits. the main aim is to help spread the heat over a larger surface to improve conduction to the final heatsink or act as a heatsink itself and increase convection.
The main advantage of doing this in ceramic versus a metal plate is the lower expansion of the material and the high dielectric strength. This will respectively, increase the reliability of the module due to reduced pump out and wear as well allow for spreading the heat from multiple
This set up is mostly used with complex rigid PCB in FR4 or flex boards where there are multiple hotspots on the board and little room to spread the heat on the PCB itself. Using thermal vias or cavities in the board the heat is been transferred from the component to the heat plate cooling down the component itself.
Furthermore, a ceramic heat plate offers hermeticity and protection from chemical hazards and the material is strong and rigid. It does not suffer from corrosion and can operate under high temperatures
Both aluminum oxide (Al2O3) and aluminum nitride (AlN) are used as a heat plate, however, the second is most often choose because of its thermal superior properties. There is also a possibility to print the circuit directly onto the heat plate making it a ceramic PCB. Read more about our solutions in ceramic PCB here.