Aluminum Nitride (AlN) ceramic substrate has good thermal conductivity, electrical properties, strength as well as 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 materials for BeO ceramics. It's 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.