2001年7月26日
ALN于1877年首次合成，但直到1980年代中期，其在微电子中的应用可能促进了高质量的商业可行材料的发展。
AlN is synthesised by carbothermal reduction of alumina or by direct nitridation of aluminium. It has a density of 3.26 g.cm-3and although it does not melt, it dissociates above 2500 °C at atmospheric pressure. The material is covalently bonded and is resistant to sintering without the assistance of liquid forming additives. Typically oxides such as Y2O3或CAO允许在1600-1900°C之间的温度下实现烧结。
Key Properties
- AlN is resistant to attack by most molten metals, most notably aluminium, lithium and copper
- It is resistant to attack from most molten salts including chlorides and cryolite
- 陶瓷材料的高热电导率（仅次于贝利利亚）
- 高体积电阻率
- High dielectric strength
- It is attacked by acids and alkalis
- In the powder form it is susceptible to hydrolysis by water or humidity
表格1。硝酸铝的典型物理和机械性能
| 财产 |
价值 |
| 密度（g.cm-3) |
3.32 |
| Modulus of rupture (MPa) |
300 - 350 |
| Modulus of elasticity (GPa) |
310 |
| Fracture toughness (MPa.m-1/2) |
3.35 |
| Coeff of thermal expansion RT-1000 °C (x10-6K-1) |
5.6 |
| Thermal conductivity (W/m.K) |
140-177 |
| Specific Heat (J.kg.K-1) |
780 |
| Volume resistivity (ohm.cm) |
1010 |
| Dielectric Strength (kV.mm-1) |
>20 |
| Dielectric constant |
8.6 |
| Loss tangent at 1 MHz |
5x10-4 |
Applications
Microelectronics
ALN展出的最引人注目的特性是其高温电导率 - 在陶瓷材料中仅次于Beryllia。亚博网站下载在中等温度（〜200°C）下，其热导率超过了铜的电导率。这种高电导率加上高体积电阻率和介电强度，导致其作为微电源或高密度组件的底物和包装的应用。限制电子组件堆积密度的控制因素之一是需要散发由于欧姆损失而产生的热量，并将组件保持在其工作温度范围内。由ALN制成的底物比常规和其他陶瓷底物提供更有效的冷却，因此它们用作芯片载体和散热器（见图1）。
|
Figure 1.AlN substrates for microelectronic applications (Photo Courtesy of Ceram Research Ltd) |
其他应用程序
Because of the cost of AlN its applications have been developed mainly for military aeronautics and transport fields.
Other applications of AlN lie in refractory composites for handling of aggressive molten metals, and high efficiency heat exchange systems.