Short answer: For ceramic and ceramic-filled boards, pick PCD or CVD-diamond tooling: PCD is 5-8x carbide hardness and alumina-grade tools last over 50x a carbide bit; run PCD on 3k-8k rpm with water-based coolant (never dry cut) at rake 0-5 deg and clearance 10-15 deg. CVD-diamond-coated microdrills reach 5-10x FR4 life on standard ceramic-filled and 10-20x on M9 grades.
Number: PCD hardness is 5-8x carbide; alumina-grade tool life exceeds 50x carbide. PCD runs at 3k-8k rpm with water-based coolant (dry cutting is prohibited), rake 0-5 deg and clearance 10-15 deg (linkuttools). PCB ceramic-filled M9 uses CVD diamond-coated microdrills at 5-10x FR4 life, 10-20x on M9; nano-ceramic AlN CCL drill life is only 32-41 percent of a PTFE board (tshztech, gopcba).
Boundary: The tool owns life and chipping; the entry/backup board stabilizes the brittle substrate. Select the bit by the ceramic grade and the laminate maker's guidance, not a generic table.
Drilling ceramic and ceramic-filled laminates is a tooling decision first. A standard carbide bit either wears out in hundreds of hits or chips the edge; the answer is diamond in one of two forms.
PCD vs CVD diamond
| Tool | Hardness / life | Use |
|---|---|---|
| PCD | 5-8x carbide hardness | Production runs, rigid setups |
| Alumina-grade | >50x carbide life | Selected ceramic grades |
| CVD diamond-coated microdrill | 5-10x FR4 life, 10-20x on M9 | Fine ceramic-filled holes |
Operating rules
- Coolant: water-based only; dry cutting is prohibited (heat cracks ceramic).
- Speed: PCD at 3k-8k rpm.
- Angles: rake 0-5 deg, clearance 10-15 deg.
- Reality check: nano-ceramic AlN CCL drill life is only 32-41 percent of a PTFE board — qualify before volume (tshztech, gopcba).
Pair the tool with a rigid, flat backup so the brittle substrate does not flex. See the no-chipping page and bit-life comparison.
