Aluminum Nitride (AlN) ceramic substrate has good thermal conductivity, electrical properties, strength, and high-temperature resistance. The AlN substrate with the properties of chemical corrosion resistance, high electrical resistivity, low dielectric loss, non-toxicity, is an excellent substitute material for BeO ceramics. It is mainly used in high-density hybrid circuits, microwave power devices, power electronic devices, optoelectronic components, semiconductor refrigeration, and other products for high-performance substrate materials and packaging materials.