Depending on the ceramic material, the AMB ceramic substrates for mature applications can be divided into: alumina, aluminum nitride and silicon nitride substrates.
AMB alumina substrate
Based on the wide source of alumina plates and the lowest cost, it is the most cost-effective AMB ceramic substrate at present, and its process is also the most mature. However, due to the low thermal conductivity and limited heat dissipation capability of alumina ceramics, AMB alumina substrates are mostly used in areas where the power density is not high and there are no strict requirements for reliability.
AMB aluminum nitride substrates
AMB substrates have higher heat dissipation capability, which makes them more suitable for some high power and high current operating environments. However, due to the relatively low mechanical strength, aluminum nitride AMB copper-clad substrates have a limited high and low temperature cyclic shock life, thus limiting their application. Aluminum nitride AMB substrates have a higher heat dissipation capacity, which makes them more suitable for some high power, high current operating environments. However, due to the relatively low mechanical strength, aluminum nitride AMB copper-clad substrates have limited high and low temperature cyclic shock life, thus limiting their application.
AMB silicon nitride substrates
The coefficient of thermal expansion of silicon nitride ceramics (2.4ppm/K) is small and close to that of silicon chips (4ppm/K); AMB silicon nitride substrates have high thermal conductivity (>90W/mK.) The combined mechanical properties of AMB-Si3N4 substrates provide excellent high temperature resistance, thermal characteristics, and ultra-high power density.
AMB-Si3N4 substrates are the preferred substrate material for automobiles, wind turbines, traction systems, and high-voltage DC drives that require high reliability, heat dissipation, and partial discharge. In addition, the current-carrying capacity is high and the heat transfer is very good.