ALN（窒化アルミニウム）：式、構造、用途

Aluminum nitride (AlN) – often abbreviated as ALN or AIN – is a ceramic compound of aluminum and nitrogen. Its molecular/chemical formula is AlN, meaning one Al atom bonded to one N atom.In the literature, "AlN" and "AIN" are used interchangeably; the chemical name is aluminum nitride (IUPAC name: aluminium nitride)  .This binary nitride crystallizes in a hexagonal wurtzite lattice (similar to GaN or ZnO).Because of the strong Al–N bonds and tetrahedral coordination, AlN is an electrical insulator with an ultra-wide bandgap (~6.1 eV).Key material properties include a high density (~3.26 g/cm³unipretec-ceramics.com), extreme hardness (~11 GPa Vickers), and outstanding thermal conductivity.

Great Ceramic offers custom AlN substrates and components (plates, washers, spacers, etc.) with excellent thermal and electrical properties. Its AlN ceramics are >96% pure and exhibit high thermal conductivity (>170–200 W/m·K)、 very low thermal expansion, high strength and hardness, and excellent electrical insulation. AlN remains stable at very high temperatures; it decomposes (effectively "melts") only above ~2200 °C.These properties make AlN an ideal material for electronic packaging and thermal management – for example, heat sinks and substrates in high-power LED modules, IGBT and MOSFET power modules, RF/microwave devices, and other circuits where efficient heat dissipation and electrical isolation are critical.In fact, AlN substrates can have thermal conductivity up to 9× that of alumina (Al₂O₃), while their coefficient of thermal expansion (~4.6×10⁻⁶/K) closely matches silicon, easing stress in chip packages.Typical AlN ceramic parts include plates, rods, tubes, washers and custom machined components – all available from Great Ceramic via precision CNC machining or laser processing.

AlN's hexagonal wurtzite structure gives each Al atom four nearest N neighbors (and vice versa). This strong ionic/covalent bonding yields an ultra-wide bandgap (~6.1 eV) semiconductor,as well as high breakdown voltage. In pure form AlN is a very good electrical insulator,with volume resistivity >10¹⁴ Ω·cm.Thermal conductivity is exceptionally high among ceramics (bulk AlN 170–200+ W/m·K;single crystals up to ~320 W/m·K.For comparison, AlN's thermal conductivity is roughly eight times that of aluminaand far exceeds that of most other technical ceramics. AlN's low thermal expansion (~4.5–5.2×10⁻⁶/K) is near silicon's (~2.6×10⁻⁶/K), minimizing thermal strain in electronics. Hardness is also high (Vickers ~11 GPa),and AlN is chemically stable (resists acids/bases and molten metal). These combined properties – high-T stability, high stiffness (Young's modulus ~320 GPa), and optical transparency in the UV – enable a wide range of uses.

AlN ceramics are used wherever heat must be efficiently moved or where insulation at high temperature and power is needed. Key applications include:

These applications leverage AlN's unique combination of thermal management and electrical insulation. In many cases AlN is chosen over alumina (Al₂O₃) or beryllium oxide (BeO) because of its superior heat conduction and similar expansion to silicon.

AlN is gaining attention as an ultrawide-bandgap (UWBG) semiconductor material. With a bandgap ≈6 e, AlN is suited for extreme high-power and high-frequency electronics. Cornell University researchers note AlN's "thermal conductivity, high breakdown voltage and strong electric field tolerance" make it ideal for next-generation power transistors and diodes. Current R&D (e.g. DARPA-funded projects) focuses on AlN-based PIN diodes with ultralow on-state resistance to cut power losses. Moreover, AlN substrates have enabled the first deep-UV diode lasers (wavelengths <280 nm) – critical for sterilization and sensing – due to AlN's lattice compatibility with aluminum gallium nitride (AlGaN) layers.

In electronic packaging, AlN ceramic substrates are playing a "game-changing" role. AlN's thermal conductivity (150–230 W/m·K) vastly exceeds alumina's, allowing heat to be routed away from chips with minimal thermal resistance.. Its thermal expansion matches silicon, enabling direct chip-attach or flip-chip bonding on AlN without inducing stress.As a result, AlN substrates are widely used in IGBT modules, power converters, and advanced LED packages.AlN is also found in advanced packaging technologies – for example, fan-out wafer-level packages and 3D stacked modules – because its high thermal performance and insulation improve reliability of dense, high-power assemblies.In short, AlN ceramics serve as both the heat sink and substrate in many cutting-edge semiconductor and electronics applications.

Great Ceramic is a professional manufacturer of AlN ceramics and custom components.We offer high-purity (>96%) aluminum nitride ceramic materials in many forms – plates, substrates, tubes, rods, washers, spacers, and fully machined parts.Our AlN parts can be custom-designed and OEM-produced with tight tolerances and optional metalization (e.g. copper or DBC coating) for power electronics. Great Ceramic's AlN ceramics typically have density ~3.3 g/cc and thermal conductivity >170 W/m·K.We support rapid prototyping and small-batch production, including precision laser cutting and grinding. To explore our ALN capabilities or request a quote, see our Aluminum Nitride (AlN) products page or contact us for technical support.