Aluminum Nitride Ceramic Cylinder for Power Electronics Thermal Management

Application of Aluminium Nitride Ceramic Cylinder

• Power Electronics Modules and Inverters

  ✅Key Advantages

  1. Lower junction temperature in compact modules – The aluminum nitride ceramic cylinder conducts heat away from busbars and substrates, helping reduce device junction temperature by several degrees in dense layouts.
  2. High-voltage insulation in confined spaces – The AlN ceramic cylinder provides creepage and clearance distances while maintaining volume resistivity above 10¹³ Ω·cm.
  3. Dimensional stability under thermal cycling – The matched expansion of the AlN cylinder reduces stress under repeated thermal cycles between ambient and operating temperature.

  ✅ Problem Solved

  A European inverter manufacturer replaced alumina spacers with aluminum nitride ceramic cylinders in a 50 kW power module. With similar geometry but higher thermal conductivity, module junction temperature dropped by about 8–12 °C at rated load. The lower temperature and better mechanical stability reduced early-life failures, and the annual scrap cost related to module overheating decreased by more than 30%.

• Industrial Vacuum and Thermal Processing Systems

  ✅Key Advantages

  1. High thermal conductivity path inside furnace fixtures – An AlN cylinder can transfer heat more evenly through fixtures, reducing temperature gradients within the working zone.
  2. Low outgassing ceramic support in vacuum – The aluminum nitride ceramic cylinder has low outgassing and stable insulation, supporting vacuum or controlled atmosphere processing.
  3. Mechanical support at elevated temperature – The AlN cylinder carries load at temperatures around 800–1000 °C in air and even higher in inert gas, reducing deformation compared with metal supports.

  ✅ Problem Solved

  A mid-size furnace OEM used aluminum nitride ceramic cylinders as support posts in a high-temperature test chamber. By replacing metallic supports, they reduced temperature variations across the test plate from ±12 °C to around ±5 °C at 900 °C. The improved uniformity shortened calibration time and reduced the number of rejected test runs, saving several production days per quarter.

• High-Temperature Sensors and Measurement Devices

  ✅Key Advantages

  1. Compact thermal bridge with full electrical insulation – An aluminum nitride ceramic cylinder can transfer heat to sensing elements while maintaining galvanic isolation.
  2. Low thermal mass geometry – Slim AlN cylinders enable fast response in temperature or flow sensors by minimizing thermal lag.
  3. Geometry tailored to probe design – The AlN ceramic cylinder can be shaped as stepped, slotted or hollow supports to integrate leads and protective housings.

  ✅ Problem Solved

  A manufacturer of high-temperature gas sensors integrated a hollow aluminum nitride cylinder into the probe design as both support and thermal conductor. The new design improved response time by roughly 20% and reduced drift over 500+ thermal cycles between ambient and 750 °C. Field returns related to mechanical cracking of the support structure dropped noticeably in the first year of use.

AlN Ceramic Cylinder Usage Instructions

• Installation

  1. Verify that the aluminum nitride ceramic cylinder dimensions and tolerances match your drawing and mating parts before assembly.
  2. Use clean, burr-free metal or ceramic mating components to avoid point loads on the AlN cylinder surface.
  3. For press-fit or interference-fit designs, follow the recommended interference ranges; excessive interference can induce tensile stress and cracking.
  4. When using screws or clamps around the AlN ceramic cylinder, tighten fasteners gradually and cross-wise so the load is distributed evenly.

• Operation

  1. Bring assemblies containing aluminum nitride ceramic cylinders up to temperature with controlled ramp rates, especially for large cross-sections or thick walls.
  2. Avoid sudden exposure of the hot AlN cylinder to cold air or liquid; strong thermal shock can generate surface cracks.
  3. Maintain the specified atmosphere (air, vacuum or inert gas) to keep electrical insulation and mechanical properties stable.

• Storage

  1. Store aluminum nitride ceramic cylinders in dry, clean conditions inside their original packaging or covered containers.
  2. Keep parts away from abrasive dust and metal chips that can scratch the surface or embed into the ceramic.
  3. Do not stack heavy objects on top of cartons containing small or thin-walled cylinders.

• Cleaning

  1. For normal dust or fingerprints, use clean compressed air and lint-free cloths; avoid hard tools that can chip the ceramic.
  2. If deeper cleaning is needed, use suitable solvents that do not leave conductive or corrosive residues, and dry parts completely before use.
  3. Do not use aggressive mechanical brushing on critical sealing or fitting surfaces of the AlN cylinder.

• Typical user issues and recommended actions

  1. Issue: Small chips at edges after assembly
  Likely cause: Over-tightening clamps or misalignment of metal hardware against the aluminum nitride ceramic cylinder.
  Action: Reduce clamping force, add chamfers to mating parts or introduce small compliant pads where possible.

  2. Issue: Cracks after fast temperature cycling
  Likely cause: Thermal shock beyond the tolerance of the AlN cylinder thickness and geometry.
  Action: Slow down heating and cooling ramp rates, redesign geometry to reduce section thickness, or review temperature gradients in the system.

  3. Issue: Unexpected leakage currents in high-voltage sections
  Likely cause: Surface contamination or conductive residue on the ceramic cylinder.
  Action: Clean the surface with appropriate solvents, avoid handling with oily gloves, and ensure drying before high-voltage testing.

FAQ – Aluminum Nitride Ceramic Cylinder

1. Q: What is an aluminum nitride ceramic cylinder used for?
   A: An aluminum nitride ceramic cylinder is a high thermal conductivity insulating post or spacer used in power electronics modules, industrial furnaces, vacuum systems and high-temperature sensors to support components while conducting heat and maintaining electrical isolation.

2. Q: What size range can you supply for aluminum nitride ceramic cylinders?
   A: We typically supply AlN ceramic cylinders with outer diameters from a few millimetres up to around 80 mm and lengths up to about 300 mm, with both solid and hollow structures depending on the design.
3. Q: How does an aluminum nitride ceramic cylinder compare with alumina or silicon nitride cylinders?
   A: Compared with alumina, an aluminum nitride ceramic cylinder offers much higher thermal conductivity and a closer thermal expansion match to silicon or SiC, while silicon nitride cylinders trade some thermal conductivity for higher fracture toughness.
4. Q: What is the maximum service temperature of an aluminum nitride ceramic cylinder?
   A: In many designs an aluminum nitride cylinder can be used continuously around 800–1000 °C in air and at higher temperatures in vacuum or inert atmospheres, but the exact limit depends on loading conditions and the surrounding materials.
5. Q: Can aluminum nitride ceramic cylinders be machined after sintering?
   A: Yes, aluminum nitride ceramic cylinders can be diamond-ground after sintering to reach defined OD, ID and length tolerances as well as surface finishes, but design changes at this stage are more costly than adapting the green body.
6. Q: What information do you need to quote a custom aluminum nitride ceramic cylinder?
   A: For a custom aluminum nitride ceramic cylinder we normally need a drawing or sketch with OD, ID, length, tolerances, end details, any slots or holes, material grade requirements and expected annual usage.

Customer Reviews – Aluminum Nitride Ceramic Cylinder

• ⭐️⭐️⭐️⭐️⭐️
  We use custom aluminum nitride ceramic cylinders from ADCERAX as support posts in our IGBT inverter stacks. The tight tolerances on OD and length simplified mechanical assembly, and the thermal performance helped us lower device temperatures in a compact housing.
  -- Daniel K., Power Electronics Engineering Manager, VoltPhase Systems (Germany)
• ⭐️⭐️⭐️⭐️⭐️
  Our engineering team specified solid and hollow AlN cylinders for a new test furnace series. ADCERAX provided clear feedback on machinable dimensions and delivered consistent batches, which made it easier to standardize internal fixture designs.
  -- Maria Lopez, Purchasing Specialist, ThermoLine Furnace Technologies (Spain)
• ⭐️⭐️⭐️⭐️⭐️
  We integrated a small aluminum nitride ceramic cylinder into a high-temperature sensor design as both support and thermal link. The stable insulation and low thermal mass improved response time compared with our previous ceramic spacers.
  -- James O’Neill, R&D Engineer, NovaSense Measurement Solutions (UK)
• ⭐️⭐️⭐️⭐️⭐️
  For our power converter platforms we require high thermal conductivity ceramic cylinders with defined tolerances. The aluminum nitride cylinders we receive from ADCERAX have been dimensionally consistent, which has reduced rework and simplified quality inspections.
  -- Satoshi Tanaka, Component Sourcing Manager, KyoTech Industrial Electronics (Japan)