| Material |
Tg (°C) |
Dk |
Df |
TCE (z) (%) (50-260ºC) |
Application / Comments |
| Multifunctional FR4 |
135 |
3.8-4.6 |
0.025 |
4.5 |
Popular PCB material used in computer and telecommunication applications etc. Can also have specific CTI. Higher Tg than Di-functional |
| Laser drillable pre-preg |
135 |
4.6 |
0.025 |
4.5 |
Easier to laser drill giving smoother hole walls |
| Getek |
180 |
3.9 |
0.012 |
3.9 |
Improved thermal and electrical properties |
| High Tg FR4 |
180 |
4.6 |
0.025 |
4.1 |
Withstands higher temperatures |
| BT / Epoxy |
185 |
4.1 |
0.015 |
3.5 |
Withstands higher temperatures. Better electrical properties – lower Dk and Df |
| Cyanate Ester |
250 |
3.7 |
0.009 |
2.5 |
Withstands extremely high temperatures and has excellent electrical properties |
| Polyimide |
260 |
4.5 |
0.013 |
1.8 |
Withstands extremely high temperatures due to high Tg and low TCE (z). Low Df |
| PTFE Alternatives |
280 3.4 |
3.5 |
0.002 |
0.004 |
Properties approaching PTFE but can be processed like FR4. Optimum frequency range 100MHz – 15GHz |
| PTFE |
260 |
2.3 |
0.001 |
|
Optimum frequency range 1 – 90GHz |
| Metal backed PTFE |
280 |
|
|
|
Can be thick Aluminium, Brass or Copper backed |
| SI glass |
|
|
|
|
Better signal integrity |
| Resin Coated Copper (RCC) |
160 |
3.4 |
0.026 |
|
Ideal for outer layers with laser micro-drilling down to penultimate layers, bonded to rigid core. No re-inforcement |
| Halogen free |
|
|
|
|
Environmentally friendly |
| Thermount |
|
|
|
|
Aramid fibre reinforcement. Epoxy or Polyimide. Easily laser ablatable. Improved / repeatable dimensional stability. Ideal for sequential bond |
