AlN ceramic circuit board, which has the largest demand of customers in the market, is widely used in high-power integrated circuits. Al 2O 3 and BeO ceramics have been used in the circuit board materials, but the thermal conductivity of Al 2O 3 substrate is low, and the coefficient of thermal expansion does not match Si; Although BeO has excellent comprehensive performance, its high production cost and high toxicity limit its application. Therefore, in terms of performance, cost and environmental protection requirements, Al2O3 and BeO ceramics can no longer meet the development and demand of electronic power devices, instead of AlN ceramic circuit board.
Properties of AlN ceramic circuit board
Aluminum nitride ceramics are a new generation of advanced ceramics with excellent comprehensive properties, which have been widely concerned in recent years. It has a wide range of application prospects in many aspects, especially with the advantages of high thermal conductivity, low dielectric constant, low dielectric loss, excellent electrical insulation, coefficient of thermal expansion matching with silicon and non-toxic, which make it a high-density, low-cost, low-cost, low-cost, high-cost, low-cost, high-cost, low-cost, high-cost, low-cost, high-cost, high-cost, low-cost, high-cost It is an ideal material for high power and high speed integrated circuit board and packaging substrate.
AlN ceramic circuit board is a heat dissipation substrate with high thermal conductivity
Among a series of important properties of AlN, the most remarkable one is high thermal conductivity. Its main mechanism is: through lattice or lattice vibration, that is, with the help of lattice wave or thermal wave transmission. Aluminum nitride ceramics are insulating ceramics. For insulating ceramics, heat energy is transmitted by atomic vibration, which belongs to phonon heat conduction. Phonon plays an important role in its heat conduction process. Theoretically, the thermal conductivity of AlN can reach 320W (m · K), but due to impurities and defects in AlN, the thermal conductivity of AlN ceramic circuit board can not reach the theoretical value. The impurities in AlN powder are mainly oxygen and carbon, and a small amount of metal ions impurities, which produce various defects in the lattice. The scattering of these defects on phonons will lead to the thermal conductivity. Even so, AlN ceramic circuit board is the highest thermal conductivity circuit board on the market.
