Because its special characteristics of DCB ceramic board, you cannot design DCB PCB following normal FR4 PCB design rule. Here are simple design guide for DCB ceramic printed circuit board.
- Conductor material: Copper, thickness 0.1mm~0.3mm;
- Copper thickness VS trace space & trace width
For 0.1mm (3OZ) copper thickness, trace space & width should be 0.3mm;
0.2mm copper, 0.4mm space & width;
0.3mm copper, 0.5mm space & width
- Maximum effective working area: 126x176mm
- Substrate (Al2O3 & AIN) thickness:
0.25mm (seldom used, extreme expensive), 0.38mm, 0.50mm, 0.63mm(standard), 0.76mm, 1.0mm, and 1.27mm (only for AIN)
- There should be 0.3mm margin between trace and edge of board at each side for 0.1mm thickness copper; 0.4mm margin for 0.2mm copper thickness; 0.5mm margin for 0.3mm copper thickness;
- Surface finishing: Nickel (1~7um); or Aug plating (0.075~0.1um, 3~4 u”)
- No soldermask is better (working temperature is -55~+850C, as most of ceramic board was working in high temperature > 200C, no good oil is suitable for that temperature range)
- We will ship via single piece, as Al2O3 need to be cut by laser and not easy de-panel like normal FR4 PCB
- ore hole, more expensive. Min hole: 0.15mm, no Max. Hole diameter > 0.5mm will be better in price.
- Normally trace should be related much simple compared with FR4 board
Knowing ceramic substrate feature will be better for you to understand and design a good board. Here is a picture showing above design guide.