DCB substrate materials
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Aluminum oxide, silicon nitride, or aluminum nitride — the selected substrate directly affects power module performance.
Designed for thermal performance and durability
Designers can choose from a range of ceramic materials and copper thicknesses. Selecting the right DCB substrate requires balancing thermal conductivity, mechanical robustness, cost and application requirements.
Aluminum oxide (Al2O3): a cost-efficient combination of thermal performance and reliability
Silicon nitride (Si3N4): robust enough for challenging use cases that prioritize reliability
Aluminum nitride (AlN): superior thermal conductivity for maximum heat dissipation in demanding power systems
Aluminum oxide (Al2O3)
Al₂O₃ combines cost efficiency with stable mechanical properties and sufficient thermal conductivity. Readily available and proven, it remains the standard substrate for conventional power module use cases.
Features:
Cost-effective material
Good thermal conductivity
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Silicon nitride (Si3N4)
Si₃N₄ is thermally conductive, mechanically robust and highly durable. It conducts heat efficiently and remains stable under mechanical and thermal stress. This makes it well suited for high-reliability power modules.
Features:
Highest physical robustness
High thermal conductivity
Lowest thermal expansion coefficient
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Aluminum nitride (AlN)
AlN efficiently conducts heat in high-power applications. Although more costly than Al₂O₃, it delivers strong thermal performance and reliable operation for demanding tasks.
Features:
Highest thermal conductivity
Low thermal expansion coefficient
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Comparing key DCB substrate properties
Al2O3 (Alumina) | Si3N4 (Silicon Nitride) | AlN (Aluminum Nitride) | |
|---|---|---|---|
Thermal conductivity (W/m*K) | 24 - 25 | ~85 - 90 | ≥ 170 (up to ~230 in premium grades) |
Bending strength (MPa) | ~400 - 500 | ~700 - 800 | ~350 - 450 |
Fracture toughness (MPa·√m) | ~3 | ≥ 6.5 | ~3 |
DCB CTE (10⁻⁶/K) 1 | ~8.3 ... 9.2 | ~4.9 ... 6.4 | ~6.6 ... 7.9 |
Thermal‑cycling reliability | good | very good | good to very good 2 |
1 CTE of full DCB stack-up depends on thickness of ceramic, top and bottom copper
2 With AMB technology
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