Aluminum nitride ceramic PCB
Aluminum nitride ceramic is a kind of ceramic material with aluminum nitride (AIN) as the main crystal phase. Etching metal circuit on aluminum nitride ceramic substrate is aluminum nitride ceramic substrate.
1. Aluminum nitride ceramic is a ceramic with aluminum nitride (AIN) as the main crystalline phase.
2. Ain crystal takes (ain4) tetrahedron as structural unit, covalent bond compound, has wurtzite structure and belongs to hexagonal system.
3. Chemical composition ai65 81%，N34. 19%, specific gravity 3.261g/cm3, white or gray white, single crystal colorless and transparent, sublimation and decomposition temperature under normal pressure is 2450 ℃.
4. Aluminum nitride ceramic is a high-temperature heat-resistant material with a coefficient of thermal expansion of (4.0-6.0) x10 (- 6) / ℃.
5. Polycrystalline ain has a thermal conductivity of 260W / (m.k), which is 5-8 times higher than that of alumina, so it has good heat shock resistance and can withstand high temperature of 2200 ℃.
6. Aluminum nitride ceramics have excellent corrosion resistance.
Ceramic circuit board has good high-frequency and electrical properties, and has properties that organic substrates do not have, such as high thermal conductivity, excellent chemical stability and thermal stability. It is an ideal packaging material for the new generation of large-scale integrated circuits and power electronic modules.
Semiconductor instruments required by living facilities and industrial equipment are developing rapidly, with high power consumption, high scale integration and modularization, high safety factor and sensitive operation. Therefore, the preparation of high thermal conductivity materials is still an urgent problem to be solved so far. The ceramics based on aluminum nitride have the most suitable comprehensive properties. And after various experiments, it has gradually appeared in people’s vision, and the largest application field is high-power LED products.
As the main path of heat flow, aluminum nitride ceramic circuit board is essential in the packaging application of high-power LED. It plays a very important role in improving the heat dissipation efficiency, reducing the junction temperature and improving the reliability and service life of the device.
LED cooling circuit board is mainly divided into: LED grain circuit board and system circuit board. LED grain circuit board is mainly used as the medium of heat energy export between LED grain and system circuit board, which is combined with LED grain by the process of wire drawing, eutectic or cladding.
With the development of high-power LED, ceramic circuit board is the main circuit board based on the consideration of heat dissipation: there are three traditional preparation methods of high-power circuit:
1. Thick film ceramic board
2. Low temperature co fired multilayer ceramics
3. Thin film ceramic circuit board
Based on the combination mode of LED grain and ceramic circuit board: gold wire, but the connection of gold wire limits the efficiency of heat dissipation along the electrode contact, so it meets the bottleneck of heat dissipation.
Aluminum nitride ceramic substrate will replace aluminum circuit board and become the overlord of high-power LED chip market in the future.