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Aluminum Nitride · Power Electronics Substrate
AlN

The thermal management ceramic —
built for power electronics and wafer heaters.

Aluminum nitride delivers thermal conductivity 170 W/m·K (nearly 6× alumina) while remaining an electrical insulator. That rare combination makes AlN the substrate of choice for power semiconductor modules, wafer-processing heaters, and laser diode submounts — anywhere heat must move out and electricity must stay in.

170
Thermal W/m·K
10¹⁴
Resistivity Ω·cm
3.26
Density g/cm³
14
Dielectric kV/mm
Certifications & Standards
ISO 9001IATF 16949CERoHS · REACHUL Recognized
01 · Material Properties

AlN by the numbers.

Properties below are typical for our standard, high-thermal-conductivity, and metallized AlN grades. Standard grade serves most heater and substrate applications; high-K grade for power-density-critical electronics.

PropertyUnitStandardHigh-KMetallized DBC
Densityg/cm³3.263.303.26 + Cu
Thermal ConductivityW/m·K170200170
Thermal Expansion (RT–400°C)×10⁻⁶/K4.54.54.5
Dielectric StrengthkV/mm141514
Volume Resistivity (20°C)Ω·cm10¹⁴10¹⁵10¹⁴
Dielectric Constant (1 MHz)8.88.78.8
Hardness (HV)Vickers110011001100
Flexural StrengthMPa320360320
Max Service Temp (inert)°C220022002200
Surface Finish (as-fired)Ra μm0.40.40.05
Thermal expansion (4.5 × 10⁻⁶/K) matches silicon (~3) and GaN/SiC power devices — minimizes thermal-cycling stress at the die/substrate interface.
02 · Three Manufacturing Forms

Pick the right AlN form factor.

AlN typically ships in one of three finished forms — bare ceramic substrate for downstream metallization, direct-bonded-copper (DBC) substrate for power module assembly, or finished heaters with integrated heating elements.

Substrate — Bare or DBC/DBA

AlN substrates as 0.25/0.38/0.63/1.0 mm thick discs or rectangles. Bare ceramic for downstream customer processing, or pre-metallized as DBC (Direct-Bonded Copper) and DBA (Direct-Bonded Aluminum) for IGBT and SiC power modules.

Best for → Power modules · IGBT · automotive inverters
🌡️
Heater — Wafer Chuck

AlN heaters with integrated tungsten or molybdenum heating elements for semiconductor wafer chucks. Used in PVD, CVD, ALD, and etch chamber wafer handling. Temperature uniformity ±1% across 200/300 mm wafer.

Best for → Semi fab equipment · wafer process chambers
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Submount — Laser & RF

Small-format AlN substrates (typically 0.5–5 mm square) with gold/silver metallization for high-power laser diode submounts, high-frequency RF packages, and high-brightness LED thermal management.

Best for → Laser diodes · RF packages · high-brightness LED
03 · Typical Applications

Where AlN shows up.

AlN ships into six application categories. Common thread: heat must move out of a power-dense device while electrical isolation is maintained.

04 · When to Choose AlN

AlN vs. the alternatives.

AlN is the only ceramic that pairs high thermal conductivity with electrical insulation. Pick it when both matter — otherwise alumina (cheaper) or BeO (toxic) might serve.

Pick AlN when…

AlN wins
  • Heat out + electricity stay in — 170 W/m·K thermal + 10¹⁴ Ω·cm resistivity, the only ceramic combining both at this level
  • Thermal expansion match to Si/SiC — 4.5 × 10⁻⁶/K closely tracks Si (~3) and SiC, low cycling stress
  • Power electronics substrate — DBC/DBA-AlN is industry-default for SiC MOSFET and IGBT modules above 500V
  • High-power RF packages — Low dielectric loss + high thermal K enables compact 5G/radar designs
  • Molten aluminum non-wetting — AlN doesn't wet molten Al, ideal for aluminum-handling crucibles
  • Replacing toxic BeO — AlN delivers similar thermal performance without beryllia's machining hazards

Reach for something else when…

Other materials
  • Cost is the driver, lower power density is OK — Use Al₂O₃: 30 W/m·K is enough for low-power isolators
  • Maximum hardness / abrasion resistance — Use SiC: HV 2800 vs AlN 1100
  • Maximum service temp in air — Use Al₂O₃ (1700°C) or SiC (1600°C); AlN oxidizes above 700°C in air
  • Maximum fracture toughness — Use ZrO₂ (10 MPa·m½) for impact-loaded service
★ Engineering Case · EV Traction Inverter OEM

SiC MOSFET inverter — DBC-Al₂O₃ to DBC-AlN: +45% power density.

An Asian Tier-1 EV inverter OEM was bumping into thermal limits on their 800V SiC MOSFET traction inverter design — DBC-Al₂O₃ substrates couldn't move heat out fast enough at peak torque demand. Switching to DBC-AlN substrates raised power density 45% in the same chassis volume, enabling them to hit the OEM's continuous-torque spec.

DBC-Al₂O₃ → DBC-AlN
Inverter switch outcome
  • +45% Peak power density
  • −12°C Junction temp at peak torque
  • −8% Inverter chassis volume
  • 5.7× K Thermal conductivity vs alumina
05 · Engineering FAQ

The questions power-electronics engineers ask.

Direct answers from our application team. Email engineering@ceramitell.com with your power-module spec or substrate drawing.

DBC-AlN vs DBC-Al₂O₃ — when does the switch make sense?
At higher power densities (typically 500V+ EV inverters, industrial motor drives above 30 kW continuous, or fast-switching SiC MOSFET modules). Below that, DBC-Al₂O₃ is more cost-effective. Run a thermal simulation with your specific die/baseplate stack — we can supply both DBC options.
How does AlN oxidize at elevated temperatures?
AlN oxidizes above approximately 700°C in air, forming an Al₂O₃ surface layer that gradually consumes the AlN. For service above 700°C, AlN must be operated in inert atmosphere (nitrogen, argon, vacuum). For air service above 700°C, switch to alumina or SiC.
What thickness AlN substrates do you stock?
Standard thicknesses: 0.25 mm, 0.38 mm, 0.63 mm, 1.0 mm, 1.5 mm. Standard panel size up to 138 × 190 mm. Custom thickness from 0.15 mm to 5 mm available with 500+ piece MOQ. DBC and DBA metallization available on most standard sizes.
Can you supply pre-singulated DBC substrates for direct module assembly?
Yes — laser-singulated DBC-AlN substrates to customer drawing dimensions, etched with custom copper pattern. Standard turnaround 4–6 weeks from approved artwork. Production MOQ typically 1,000+ pieces.
Is AlN compatible with brazing and active-metal joining?
Yes — AlN can be brazed to metals using active-metal brazes (TiCuSil, CuSil-ABA). Common in laser submount and high-power RF package assemblies. We provide pre-brazed assemblies for OEM customers on volume orders.
What's the lead time for custom AlN heaters?
Custom AlN heaters with embedded tungsten heating elements: 6–10 weeks for first prototype (tooling-dependent), 8–12 weeks for production runs. DFM review and quote within 48 hours of receiving design specs and operating conditions.