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Excellent thermal and electrical properties

Aluminium Nitride AlN Substrates

Achieving maximum performance in minimum space inevitably means that power semiconductors develop ever higher temperatures. To protect the components and connection technology, this heat must be dissipated quickly and reliably. This is where CeramTec's aluminium nitride ceramic Alunit® sets standards.

Aluminium nitride substrates in front of a firewall.

Substrates made of aluminium nitride AlN HP convince with outstanding thermal and electrical properties, high flexural strength (450MPa), longer durability (thermocycling), excellent thermal conductivity (170W/mK) as well as high resistance to abrasion and and oxidation. AlN HP is therefore ideal for very high power electronics and is used in the areas of trains & railways, industry and renewable energies as well as in high power density modules.

Due to the coefficient of expansion adapted to chip materials, AlN HP is excellently suited as an insulation material in the field of power modules. Aluminium nitride substrates also have a significantly higher thermal conductivity with better temperature resistance and insulation capability than PCB materials. This makes such materials suitable for use in high-power LEDs and passive components such as chip resistors.

Aluminum Nitride (AlN) - Discover more information & examples of use

AlN Substrates

Key Advantages

Split image: On the left is a modern electrified train, on the right two men walk over a solar installation
Aluminium Nitride AlN Substrates - For Rail & Renewables

Technical Values & Parameters

Physical properties

  • Density: ≥ 3.34 g/cm3


Surface properties

  • Ra value: ≤ 0.4 µm


Mechanical properties

  • Flexural strength (double ring): 450 MPa


Thermal properties

  • CTE: 100-200°C: ± 3.7 - 5.7 10-6/K
  • CTE: 100-300°C: ± 3.7 - 5.7 10-6/K
  • CTE: 100-600°C: ± 4.5 - 5.9 10-6/K
  • CTE: 100-800°C: ± 4.8 - 6.2 10-6/K
  • Specific heat capacity at 20°C: 0,6 J/gK bei 100°C: 0,7 J/gK
  • Thermal conductivity at 20°C: ≥ 170 W/mK

Electrical properties

  • Dielectric strength: ≥ 15kV/mm


Geometry - Masterplates

  • 190.5 x 138.0 x 0.635 mm (7.5" x 5.4" x 0.025")
  • Length and width tolerance: +/- 2%
  • Thickness tolerance: +/- 10%
  • Curvature: 0.3% 


Geometry - lasered substrates

  • Thickness: 0.635mm (0.025")
  • Length and width tolerance: + 0.20 mm / - 0.05 mm (+0.0079" / 0.002")

Download Datasheet

Substrate Data Sheet: Alunit AlN HP
Material Properties Aluminum Nitride

Ceramic Substrates Application Areas

List of materials and markets for CeramTec substrate solutions

Please click to enlarge

CeramTec Substrates in Comparison

MaterialFlexural strength
Thermal conductivity
Dielectric strength
Al2O34506 - 92215
AlN4504 - 617015
ZTA6257 - 92625
Si3N47002 - 48025


Technical Values