Advantages of Ceramic PCB
The main material of ceramic substrate
Alumina is the most commonly used substrate material in ceramic substrates, because compared with most other oxide ceramics, it has high strength and chemical stability in terms of mechanical, thermal science and electrical properties. technology. Manufacturing and different shapes. The percentage of alumina (Al2O3) can be divided into: 75 porcelain, 96 porcelain, and 99.5 porcelain. The content of alumina is different, and its electrical properties are hardly affected, but their mechanical properties and thermal guidance are very different. There are many glass with low purity substrates, and the surface roughness is large. The higher the purity of the substrate, the smoother, the dense, and the lower the dielectric loss, but the higher the price.
It has a higher thermal conductivity than metal aluminum, which requires high thermal guidance applications. After the temperature exceeds 300 ° C, the temperature drops rapidly, but its toxicity limits its own development.
Aluminum nitride (aln)
Aluminum nitride ceramics are ceramics with aluminum nitride powder as the main crystal phase. Compared with alumina ceramic substrates, it has higher insulation resistance, higher insulation resistance and lower dielectric constant. Its thermal conductivity is 7-10 times that of AL2O3, and its thermal expansion coefficient (CTE) is similar to the silicon wafer, which is essential for high-power semiconductor chips. In the production process, ALN’s thermal guidance rate is greatly affected by the content of remnant oxygen impurities, and reducing oxygen content can significantly increase thermal guidance. At present, the heating coefficient of the process production level exceeds 170W/(m · k) is no longer a problem.