Aluminum Nitride Ceramic Overview
1.1 Definition
Aluminium nitride (AlN) is a solid nitride of aluminium. Its wurtzite phase (w-AlN) has a band gap of ~6 eV at room temperature. It is considered as the ideal material for the new generation of heat dissipation substrates and electronic device packaging.
For the properties,
Ø Thermal conductivity: theoretical 320 W/(m·K); actual more than 180 W/(m·K);
Ø thermal expansion coefficient： 4. 5×10－6 K－1 (room temperature ~ 400 ℃);
Ø Excellent electrical properties (dielectric constant, dielectric loss, volume resistivity and dielectric strength);
Ø good mechanical performance, flexural strength beter than that of Al2O3 and BeO ceramic, can be pressureless sintering;
Ø optical transmission characteristics;
Ø non-toxic.
1.2 Perparation
The preparation of aluminum nitride ceramics includes 3 processes: powder preparation, forming and sintering.
Powder preparation: Aluminum nitride powder is a raw material for ceramic preparation. Its purity, particle size, oxygen content and impurity content have an important influence on the thermal conductivity and the subsequent sintering and forming processes.
Forming: According to the different preparation requirements and the difficult levels of the technological process, the manufacturing should take suitable forming method. For example, AlN substrates are formed by the fluidization method.
Sintering: This process affects directly the microstructure of ceramics, such as grain size and distribution, porosity etc, which is an important step of ceramic preparation.
1.3 Application
Aluminum nitride has become an important precision ceramic material due to its high thermal conductivity, high insulation resistance coefficient, excellent mechanical strength and thermal shock resistance, etc. It is the ideal heat dissipation and packaging material for the new generation of large-scale integrated circuits, semiconductor module circuits and high-power devices.
Aluminum Nitride Ceramic Industry Chain Analyses
Aluminum nitride ceramic products are mainly used in aerospace & defense, electronic & electrical fields of heat dissipation, ceramic electronic substrate and electronics component packaging materials, etc.
Upstream raw material: Al2O3, AlCl3, N2, NH3 chemicals etc, sintering aids.
Midstream: Aluminum nitride powder, aluminum nitride products.
Downstream: Thermal conductive substrate, electronic packaging materials, crucible, thermocouple protection tube etc.
The main factors affecting the quality of AlN ceramics are the properties of powder, modification of powder, forming process and sintering process, etc., and the properties of powder are the key factors determining the preparation process and quality of AlN ceramics.
Aluminum Nitride Ceramic Market Analyses in CHINA
3.1 Powder output
China's AlN powder production can not meet the domestic market demand, need to import a large quantity of AlN powder every year;
As China's AlN powder projects have been put into operation and the capacity utilization rate has been improved, the output of AlN powder has been rising rapidly. The annual output in 2019 has reached about 740 tons, and the compound growth rate from 2014 to 2019 has exceeded 50%. But the growth rate is expected to slow down, and the annual output is expected to be about 1,000 tons in 2020.
3.2 Market demand
With the development of the electronics industry in recent years, the market demand for aluminum nitride and its products has increased rapidly, with an average annual growth rate of over 50%.
In 2019, the market demand of AlN powder in China is about 2,710 tons, with a lower growth rate than previous years. It is expected that in the next few years, China's demand for AlN powder will still keep the growth rate at about 30%; In 2022, the estimated chinese market capacity will be about 5,500 tons.
3.3 Semiconductor Assembly & Test - driving force
Ceramic packaging material is a kind of electronic packaging material, which is used for mechanical support, seal and heat dissipation of electronic components.
At present, the ceramic substrate materials used for production mainly include Al2O3, BeO and AIN, etc. Due to AlN's excellent physical and chemical properties, it has gradually become the first choice of packaging materials.
As a carrier for various types of chips (IGBT, 5BT, RESISTANCE, SiC, etc.), AlN ceramic substrate should be able to separate the chip and the module cooling plate, effectively increase the module's insulation performance.
Aluminum Nitride Ceramic Growing Trend
4.1 Technology development trend
Ø The development direction of AlN preparation technology is to obtain high performance powder with higher purity, controllable particle size and uniform dispersive morphology.
Ø Product diversification trend: develop a variety of specifications of AlN powder to meet the demands of thermal conductive ceramic substrates, AlN single crystal semiconductor, high purity of target materials and thermal conductive filler.
Ø To improve product batch stability, increase production efficiency, reduce production cost, technology and equipment continuous optimization is the manufacturer's key point.
4.2 China market demande trend
In the next few years, China's aluminum nitride market demand will continue to maintain a growth rate of 30% (estimated). The main demand driving performance is shown in the following aspects:
Ø with LED lighting products especially high-power outdoor lighting products' cooling improving requirements, the demand of aluminum nitride ceramic substrate will be rapid growth;
Ø China is gradually becoming the global auto market back-lighting products production centre, LED lamp market demand for aluminum nitride ceramic substrate will also grow rapidly;
Ø "Military and civilian integration" industry increasing demand for high-performance materials, high performance aluminum nitride, will get more extensive application.
