Aluminum Nitride Ceramic Plates are flat parts used as wear plates, insulating barriers, substrate blanks, heat spreaders and precision reference surfaces.
Aluminium nitride plates are heat spreaders. They sit under power devices and heat sinks where the plate has to move heat away while staying electrically insulating, and they are the standard replacement for beryllium oxide in this role.
Aluminium nitride is the thermal-management ceramic. Conductivity of 170-200 W/m·K rivals metals while the material stays an electrical insulator, and its 4.5 ×10⁻⁶/K expansion sits close to silicon, which is why it underpins power electronics substrates.
It degrades in humid or alkaline conditions unless protected, its flexural strength of 300-350 MPa is only moderate, and it costs considerably more than alumina.
Specifications
| Maximum size | up to 400×400 mm |
| Thickness | 0.3-30 mm |
| Flatness | 0.005 mm per 100 mm |
| Parallelism | 0.01 mm |
| Surface finish | Ra 0.4 µm ground, Ra 0.2 µm lapped |
| Holes and slots | ground, drilled or laser cut |
| Edges | square, chamfered or radiused |
Aluminium Nitride Properties
| Composition | Aluminium nitride |
| Density | 3.26 g/cm³ |
| Vickers hardness | 1100-1200 HV |
| Flexural strength | 300-350 MPa |
| Fracture toughness | 2.5-3.5 MPa·m½ |
| Max. service temperature | 1000°C |
| Thermal conductivity | 170-200 W/m·K |
| Thermal expansion (20-1000°C) | 4.5 ×10⁻⁶/K |
Machining and Tolerances
Plates are pressed or tape cast, fired, then surface ground and lapped. Thin large plates are the most likely to warp, so material is removed in equal amounts from both faces to keep the stress balanced, and grinding is followed by a relaxation step before the final passes.
Where It Is Used
- Wear plates and chute liners in bulk handling
- Electrical insulation barriers in switchgear and heaters
- Hot platens and press tooling in electronics manufacturing
- Vacuum chuck and metering surfaces in semiconductor equipment
- Precision reference and gauge blocks in metrology
Frequently Asked Questions
How flat can a large ceramic plate be held?
0.005 mm per 100 mm is the working standard for lapped plates. Larger areas are harder, and above 300×300 mm we generally specify flatness over a defined area rather than across the whole plate.
Will it warp when I bolt it down?
It can. A plate that is flat when unclamped will follow a distorted mounting face, so we recommend a relieved or lapped mounting surface, evenly torqued fixings and a compliant interlayer.
