What is Ceramic PCB?
A Ceramic PCB is a printed circuit board that uses a ceramic base material. Unlike regular PCBs, which often use materials like FR-4 (a composite of epoxy and woven fiberglass), ceramic PCBs use thermally conductive ceramics like alumina (Al2O3), aluminum nitride (AlN), or beryllium oxide (BeO). These materials are chosen because they can handle high temperatures and conduct heat well.
What are the different types of ceramic PCB?
There are different types of ceramic PCBs, which can be classified by the type of ceramic used and the way they are made. The most common types are: Alumina (Al2O3) PCBs, Aluminum Nitride (AlN) PCBs, and Beryllium Oxide (BeO) PCBs.
Comparison of Ceramic PCB Materials:
| Material | Thermal Conductivity (W/mK) | Typical Applications |
|---|---|---|
| Alumina (Al2O3) | 24-28 | LEDs, Power Circuits |
| Aluminum Nitride (AlN) | 170-200 | High-frequency RF Applications |
| Beryllium Oxide (BeO) | 250-330 | Military and Aerospace |
How to manufacture ceramic PCB?
1. Thick Film Technology
- Substrate Preparation: Clean the ceramic substrate.
- Printing and Firing: Apply conductive, insulating, and resistive pastes onto the substrate using screen printing techniques, then fire at high temperatures.
2. Thin Film Technology
- Material Deposition: Deposit conductive materials onto a clean ceramic substrate.
- Patterning: Use photolithography to create circuit patterns, followed by etching.
3. Direct Bonded Copper (DBC)
- Copper Bonding: Bond copper directly to the ceramic substrate at high temperatures and under controlled atmosphere.
- Patterning: Form the desired circuit patterns through etching.
These are the basic steps for making ceramic PCBs using different technologies. You choose the technology based on what you need the board to do, such as resist high temperatures, communicate at high frequencies, or conduct heat.
The advantages of ceramic PCB
Ceramic PCBs offer several advantages over traditional PCBs made from materials like FR-4:
- Higher Thermal Conductivity: Efficient heat dissipation keeps components cooler, enhancing performance and longevity.
- Greater Mechanical Strength: Ceramic substrates are more robust, resisting breakage and bending.
- Improved Electrical Insulation: Higher electrical insulation properties reduce the risk of short circuits and electrical failures.
Is FR-4 Ceramic?
FR-4 is a popular material for PCBs, but it's not ceramic. It's a fiberglass-reinforced epoxy laminate, which doesn't have the same level of thermal conductivity or heat resistance as ceramics.
