Ceramic substrate AlN

for power electronicsaluminum nitride

Multilayer Aluminum Nitride (AlN) substrate and package — up to 15 internal routing layers, 170–180 W/m·K
TDK's AlN multilayer substrates and packages are designed for wide-band-gap power electronics, delivering increased power density, improved heat dissipation, reduced footprint and higher reliability by combining high thermal conductivity, compatible thermal expansion with SiC/GaN/Si and advanced multilayer routing and shielding options.

AlN ceramics

• Efficient heat dissipation and excellent insulating properties
  AlN offers much higher thermal conductivity than many ceramics and substrate materials (≈170–180 W/m·K).
• Reduced EMI thanks to embedded shielding
  Multilayer architecture enables internal EMI shielding layers positioned at the source of emissions.
• Multilayer design for compact packages and substrates
  Customer-specific substrates and 3D packaging with up to 15 internal routing layers.

Main benefits in detail
Efficient heat dissipation and excellent insulating properties

• High thermal conductivity (~170–180 W/m·K) allows drastically smaller substrate footprints to dissipate equivalent thermal power versus Al2O3 or Si3N4.
• Thermal expansion coefficient closely matches SiC, GaN and Si, enabling stable long-term mechanical and thermal bonding.

Reduced EMI thanks to embedded shielding

• Shielding layers can be routed inside the multilayer substrate so protection is applied locally where EMI is generated.
• External filtering can be reduced or eliminated, lowering system complexity and cost.

Smaller and more compact packages and substrates

• Multilayer routing increases power density, minimizes footprint and reduces loop inductance by enabling up to 15 internal routing layers.
• Short electrical contacts lower parasitics and enable higher switching frequencies, allowing smaller passive components and reduced system cost.

Heat dissipation and footprint
AlN yields a very local heat spread from the source due to its high thermal conductivity. For a given heat source and power, AlN enables significantly smaller substrate footprints compared with Si3N4 or Al2O3. Typical footprint reductions: approx. 5× vs Si3N4 and up to 12× vs Al2O3, reducing enclosure size, loop inductance and thermal-management effort.

Features that bring your power electronics to the next level
Wide-band-gap semiconductors benefit from a high-performance smart substrate. Key features include:

• Shielding layers — internal shielding layers routed to suppress EMI at the source.
• Minimized stray inductance — antiparallel and multilayer routing reduce stray inductance.
• Embedded Faraday cages — local shielding structures for power and signal lines.
• Integrated bus bars — multilayer bus-bar designs for phase current distribution and local decoupling.
• Embedded temperature measurement — tungsten or similar structures under the die for fast temperature sensing.
• Cavities for embedded components — enable closer die/component placement, planar top surfaces and reduced distances to controller boards.
• Power vias — copper-laminated vias between top and bottom layers for high-current transfer.
• Multisubstrate approach — stacked substrates and cavity integration provide extra heat paths and allow bondwire removal when using alternative interconnects (e.g., silver sintering).

Material properties
Ceramics: single-layer or multilayer aluminum nitride (AlN)
Thermal conductivity at 25 °C: 170–180 W/m⋅K
Tensile stress limit (bending strength): 450–500 MPa
Young's modulus: 320 GPa
Thermal expansion coefficient: 4.7 ppm/K
Dielectric constant: ≈8.7
Isolation resistance @ 500 V (25 °C): 7.0 × 10^14 Ω
Dielectric strength / breakdown voltage: 30 kV/mm
Loss factor (tan delta): 2.0 × 10^-14

Technical characteristics / specifications

• Thermal conductivity: ≈170–180 W/m⋅K (at 25 °C)
• Tensile stress limit (bending strength): 450–500 MPa
• Young's modulus: ≈320 GPa
• Thermal expansion coefficient: ≈4.7 ppm/K (compatible with SiC/GaN/Si)
• Dielectric constant: ≈8.7
• Isolation resistance @500 V (25 °C): ≈7.0 × 10^14 Ω
• Dielectric strength: ≈30 kV/mm
• Loss factor (tan δ): ≈2.0 × 10^-14
• Multilayer routing: up to 15 internal routing layers
• Embedded EMI shielding layers and Faraday-cage options
• Power vias copper-laminated for high-current transfer
• Options for embedded temperature sensing and cavities for component embedding
• Typical footprint reduction: ~5× vs Si3N4, up to ~12× vs Al2O3 (for same heat dissipation)