Kingdta manufactures ceramic PCBs on alumina (Al2O3), aluminum nitride (AlN), and beryllium oxide (BeO) substrates for applications requiring thermal conductivity, electrical isolation, and dimensional stability beyond the capability of polymer-based PCB materials.
What Is a Ceramic PCB?
Ceramic PCBs use inorganic ceramic materials as the substrate instead of the organic polymer (epoxy/glass fiber) used in standard FR4. The most common ceramic substrates are alumina (Al2O3, 96% purity) with thermal conductivity of 24 W/m·K, and aluminum nitride (AlN) with thermal conductivity of 170 W/m·K — more than 500× better than FR4.
Ceramic substrates also offer excellent electrical isolation (dielectric strength > 15 kV/mm), extremely low CTE (6–8 ppm/°C, closely matching silicon and GaN die), and stability at operating temperatures up to 350°C. These properties make ceramic PCBs the substrate of choice for high-power semiconductor packaging, RF power amplifiers, and aerospace electronics.
Kingdta manufactures ceramic PCBs using DBC (Direct Bonded Copper) and thick-film processes. DBC bonds copper foil directly to the ceramic substrate at high temperature, creating a metallurgical bond with no adhesive layer. Thick-film uses screen-printed and fired metal paste to create conductors, resistors, and dielectric layers.
Technical Specifications
Key Advantages
Ultra-High Thermal Conductivity
AlN at 170 W/m·K enables direct die attachment for power semiconductors without additional heatsink in many applications.
High-Temperature Stability
Stable to 350°C continuous — suitable for automotive underhood, aerospace, and industrial high-temperature environments.
CTE Match to Silicon
6–8 ppm/°C CTE closely matches silicon (2.6 ppm/°C) and GaN (5.6 ppm/°C), minimizing die attachment stress in thermal cycling.
Excellent Electrical Isolation
> 15 kV/mm dielectric strength enables high-voltage isolation in power modules and EV inverters.
No Organic Outgassing
Ceramic substrates produce no outgassing in vacuum environments — required for space and some medical applications.
Chemical Resistance
Resistant to most acids, bases, and solvents — suitable for harsh chemical environments.
Where It's Used
Power Electronics
IGBT modules, SiC/GaN power devices, EV inverters
RF Power Amplifiers
GaN PA substrates, high-power RF modules
Aerospace
Avionics, satellite power systems, space electronics
Automotive
EV traction inverters, underhood electronics
Medical
High-power laser drivers, implantable devices
Industrial
Induction heating, plasma systems, welding equipment
LED
High-power UV LEDs, laser diode packages
Defense
Radar transmitters, EW systems
Why Choose Kingdta for Ceramic PCB?
- DBC and thick-film ceramic PCB processes — both available from a single supplier
- AlN substrate capability for maximum thermal performance applications
- Engineering consultation on substrate selection, metallization, and die attachment
- Precision laser cutting for complex ceramic substrate shapes
- ISO 9001:2015 certified process with full material traceability
- Experience with aerospace, medical, and power electronics ceramic applications
Frequently Asked Questions
When should I use AlN instead of Al2O3?
Use AlN (170 W/m·K) when thermal resistance is the primary constraint — typically for power densities above 50 W/cm² or when junction temperature targets cannot be met with Al2O3 (24 W/m·K). Al2O3 is significantly less expensive and is suitable for most LED and moderate power applications.
What is DBC and how is it different from standard PCB?
DBC (Direct Bonded Copper) bonds copper foil directly to the ceramic substrate at 1065°C using a Cu-O eutectic reaction — no adhesive layer. This creates a metallurgical bond with very low thermal resistance. Standard PCBs use an adhesive or prepreg layer between copper and substrate, which adds thermal resistance.
Can you assemble components on ceramic PCBs?
Yes. We assemble SMT components on ceramic PCBs using high-temperature solder pastes (SAC305 or AuSn) and custom reflow profiles. We also offer die attachment and wire bonding for bare die assembly on ceramic substrates.
What is the minimum order quantity for ceramic PCBs?
Minimum order is 10 pieces for standard sizes. Custom shapes and sizes require a minimum of 20 pieces due to the laser cutting setup cost. We offer prototype quantities from 5 pieces with a NRE charge for custom tooling.
Related PCB & PCBA Types
AlN DBC Substrate for 800V SiC MOSFET Half-Bridge Module
A Swiss power electronics company developing an 800V/300A SiC MOSFET half-bridge module for EV traction inverters — targeting a power density of 35 kW/L in a water-cooled housing.
The Problem
The customer's initial design used Al2O3 DBC substrates (24 W/m·K). Thermal simulation showed SiC die junction temperatures of 168°C at full load — 18°C above the 150°C maximum junction temperature. The only solution without redesigning the cooling system was to switch to AlN DBC (170 W/m·K).
Key Challenges
- AlN DBC requires different bonding temperature profile than Al2O3 — process qualification needed
- 800V isolation requirement: dielectric withstand ≥6000V between copper circuit and base plate
- SiC die attach using AuSn solder — requires nitrogen atmosphere reflow at 320°C
- Substrate flatness ≤0.05mm over 60mm × 40mm — critical for thermal interface to water-cooled baseplate
- AEC-Q101 automotive qualification testing required for OEM program
Our Solution
We qualified AlN DBC with 0.3mm copper on both sides, using a modified bonding cycle optimized for AlN's higher bonding temperature (1075°C vs. 1065°C for Al2O3). The substrate flatness specification of ≤0.05mm was achieved by implementing a controlled cooling rate after bonding to minimize warpage. All substrates were 100% tested for dielectric withstand at 7000V (25% margin above 6000V requirement) and flatness measured by laser profilometry before shipment. We also provided AuSn solder preforms and process parameters for the customer's die attach operation.
Results & Outcomes
"Kingdta was one of very few suppliers who could qualify AlN DBC on our timeline. Their process documentation was thorough, and the flatness consistency across the production lot was better than we achieved with our previous European supplier at twice the price."
Power Module Design Engineer, Power Electronics Company — Zurich, Switzerland