Ceramic PCB Substrate
Al2O3, AlN, Si3N4 | Thermal 24-170 W/mK | 1000C+ operation — for SiC/GaN power modules, RF power amplifiers, and extreme environments.
24-170
W/mK Thermal
1000 C+
Max Temp
SiC/GaN
Power
DBC/AMB
Bonding
What is Ceramic PCB?
Ceramic PCB substrates (alumina Al2O3, aluminum nitride AlN, and silicon nitride Si3N4) provide thermal conductivity 100-500x higher than organic substrates, enabling power density levels impossible with FR-4 or even metal-core PCBs. They are the substrate of choice for SiC and GaN power semiconductor modules driving the EV and renewable energy revolution.
Two primary bonding technologies attach copper to ceramic: DBC (Direct Bonded Copper) uses a copper-oxide eutectic bond at 1065C for cost-effective high-volume production, while AMB (Active Metal Brazing) uses a titanium-silver-copper braze alloy for superior thermal cycling endurance required in automotive and aerospace applications.
The ceramic substrate market is experiencing explosive growth driven by electric vehicle inverter modules, where SiC MOSFETs operating at 175C junction temperature and switching at 800V demand substrates that can conduct 100+ W/cm2 while maintaining electrical isolation at 2.5kV or higher.
100-500x FR-4 Thermal
24-170 W/mK versus 0.3 W/mK organic substrates.
SiC/GaN Compatible
Handles power densities required by wide-bandgap semiconductors.
1000C+ Operation
Inorganic substrate with no thermal decomposition limit.
High Voltage Isolation
2.5-10kV isolation with thin ceramic substrates.
Ceramic PCB Key Properties
Representative values from the manufacturer datasheet.
| Property | Value | Why it matters |
|---|---|---|
| Thermal conductivity (Al2O3) | 24 W/mK | Standard ceramic — cost-effective, adequate for many power applications. |
| Thermal conductivity (AlN) | 170 W/mK | Premium ceramic — 7x alumina for highest power density. |
| Thermal conductivity (Si3N4) | 70-90 W/mK | High strength — best thermal cycling, automotive EV. |
| Breakdown voltage | 10-20 kV/mm | Inherently high isolation for power module safety. |
| CTE | 6-8 ppm/C | Matched to SiC (4 ppm) and GaN (5.6 ppm) dies. |
| Flexural strength (Si3N4) | 700+ MPa | Mechanical robustness for thermal cycling without cracking. |
| Operating temperature | Up to 1000C+ | No organic decomposition limit. |
| Copper bonding | DBC or AMB | 300um+ copper for high-current power modules. |
| Surface finish | Nickel, Gold, Silver | Wire-bond and solder compatible metallizations. |
Ceramic Substrate Selection for Power Modules
Alumina (Al2O3, 96%) remains the workhorse for moderate power applications: IGBT modules below 200A, LED high-power assemblies, and RF power amplifiers. Its 24 W/mK thermal conductivity and low cost make it adequate when power density stays below 50 W/cm2. DBC alumina dominates the industrial power module market by volume.
Aluminum nitride (AlN, 170 W/mK) handles the highest power densities for laser diodes, GaN HEMT amplifiers, and compact SiC modules where thermal resistance must be absolutely minimized. Its CTE (4.5 ppm/C) closely matches SiC (4 ppm), reducing die-attach stress. Cost is 3-5x higher than alumina.
Silicon nitride (Si3N4, 70-90 W/mK) is the emerging choice for automotive EV inverters. Its flexural strength (700+ MPa versus 300 MPa for alumina) provides dramatically better thermal cycling endurance — surviving 3000+ power cycles between 25C and 175C where alumina substrates crack after 300-500 cycles. Major EV platforms are standardizing on Si3N4 AMB substrates.
EV Inverter Standard
Si3N4 AMB becoming the automotive SiC inverter substrate of choice.
Wide-Bandgap Ready
CTE-matched to SiC and GaN for direct die attach reliability.
Thermal Cycling Champion
Si3N4 survives 3000+ cycles where alumina fails at 300-500.
High Voltage Isolation
10+ kV/mm inherent dielectric strength for safety-critical modules.
Ceramic Substrate Material Comparison
Selecting the right ceramic for your power module application.
| Material | Dk | Df | Best For |
|---|---|---|---|
| Al2O3 (Alumina) DBC | 24 W/mK | Low cost | Standard power modules, RF, LED — highest volume. |
| AlN (Aluminum Nitride) DBC | 170 W/mK | High cost | Maximum thermal — laser diodes, GaN PA, compact SiC. |
| Si3N4 (Silicon Nitride) AMBThis page | 70-90 W/mK | Premium | EV inverters — best thermal cycling, automotive standard. |
| Copper MCPCB | 1-3 W/mK | Lowest cost | Budget power — when ceramic isolation not needed. |
| Organic FR-4 | 0.3 W/mK | Baseline | Reference only — inadequate for power module applications. |
Ceramic PCB Applications
SiC/GaN power modules, RF power amplifiers, IGBT substrates, EV inverters, aerospace, laser diodes
EV Traction Inverters
SiC MOSFET power modules for 400V and 800V electric vehicle drivetrains.
Industrial Power Modules
IGBT and SiC modules for motor drives, solar inverters, and UPS systems.
RF Power Amplifiers
GaN HEMT power amplifiers for radar, 5G massive MIMO, and broadcast.
High-Power Laser
Laser diode bar and stack thermal management on AlN substrates.
Renewable Energy
Power conversion modules for solar, wind, and battery storage systems.
Aerospace Power
Radiation-hardened power converters for satellite and launch vehicle systems.
Ceramic PCB Design Considerations
Select ceramic type based on primary requirement: Al2O3 for cost-sensitive moderate power, AlN for maximum thermal performance, Si3N4 for maximum thermal cycling endurance (automotive). The cost ratio is approximately 1x (Al2O3) : 3-5x (AlN) : 4-6x (Si3N4).
DBC copper thickness is typically 300um (standard) to 800um (high current). Thicker copper improves current capacity but increases thermal cycling stress. AMB enables thicker copper with better reliability due to the ductile braze layer absorbing CTE mismatch stress.
Get Instant QuoteMatch Ceramic to Need
Al2O3 for cost, AlN for thermal, Si3N4 for cycling endurance.
DBC vs AMB
DBC for cost/volume. AMB for automotive thermal cycling reliability.
Copper Thickness
300um standard, up to 800um for high current. Thicker = more stress.
Isolation Design
Verify creepage/clearance at operating voltage per IEC 60664.
Genuine Ceramic PCB, Verified on Every Order
Material CoC
Certificate of Conformance with lot number ships with every order.
Stock Verified
We confirm laminate availability before order confirmation.
No Substitutions
Specified material guaranteed — never swapped without written approval.
FAQ
Ceramic PCB Questions
What is ceramic PCB?
A printed circuit substrate made from inorganic ceramic (Al2O3, AlN, or Si3N4) with bonded copper conductors, providing 100-500x better thermal conductivity than organic PCBs for power semiconductor modules.
DBC vs AMB — which bonding method?
DBC (Direct Bonded Copper) for cost-effective volume production. AMB (Active Metal Brazing) for superior thermal cycling endurance — required for automotive EV and aerospace applications.
What ceramic for EV inverters?
Si3N4 AMB is the emerging standard. Its 700+ MPa flexural strength survives 3000+ thermal cycles between 25C and 175C, far exceeding alumina DBC.
Can AtlasPCB produce ceramic PCBs?
Yes. We offer Al2O3 DBC, AlN DBC, and Si3N4 AMB substrates with pattern etching, metallization, and testing. Prototype to production quantities.
What is the lead time for ceramic substrates?
Standard Al2O3 DBC: 2-3 weeks. AlN and Si3N4 AMB: 3-5 weeks. Custom sizes and patterns available.
Need ceramic PCB substrates?
Al2O3, AlN, Si3N4 — DBC and AMB bonding — for SiC/GaN power modules and extreme environments.
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