A prepreg (from pre-impregnated) is fibreglass impregnated with resin. The resin is pre-dried, but not hardened, so that when it is heated, it flows, sticks, and is completely immersed. Prepregs are thus fibreglass strengthened by an adhesive layer (similar to FR4 material). The name of each prepregs derives from the type of fibreglass used.
The prepreg types of different suppliers vary in thickness; in addition there are the versions "SR" Standard Resin, "MR" Medium Resin "and" HR "High Resin, depending on the resin content. The best possible material is used depending on the desired final thickness, layer structure or impedance. The mentioned thicknesses are thus to be considered only as examples. Contact us for technical advice.
Prepregs and cores are also available in High-Tg and halogen-free types, but not always in every possible thickness.
For customer layer buildup, please always state the desired final thickness, not just the prepreg.
Prepregs
We have the following FR4 prepregs in stock:
| Type | Typical thickness | After pressing* |
|---|---|---|
| 1080 | 75µm | approx. 70µm |
| 2116 | 120µm | approx. 115µm |
| 7628 | 190µm | approx. 180µm |
The following FR4 prepregs are partially in stock, or are available for order:
| Type | Typical thickness | After pressing* |
|---|---|---|
| 106 | 60µm | approx. 55µm |
| 2125 | 105µm | approx. 100µm |
| 2165 | 160µm | approx. 150µm |
Cores
Circuit boards cores are pre-pressed layers according to the pattern: copper foil – prepreg – copper foil. Multi-CB also manufactures printed circuit boards with metal core. PCB cores that are not in stock can also be pressed for specific projects.
Multi-CB normally has the following circuit boards cores in stock:
| Thickness | Copper thickness |
|---|---|
| 50µm | 18µm/18µm |
| 100µm | 18µm/18µm; 35µm/35µm |
| 150µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
| 200µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
| 300µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm |
| 350µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm |
| 400µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm |
| 500µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm |
| 550µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm |
| 600µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm |
| 700µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm |
| 800µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm |
| 900mm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
| 1000µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
| 1200µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
| 1500µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 175µm/175µm |
| 2000µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
| 2400µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
| 3200µm | 18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm |
Copper foils
The copper for the outer layers of multilayer boards is applied in the form of copper foil and pressed together with the prepregs / cores. For use with microvias, the copper foil is replaced by RCC foil (Resin Coated Copper).
We have copper foil in the following thicknesses in stock:
| 12µm | 18µm | 35µm | 70µm | 105µm | 210µm |
|---|
The following FR4 prepregs are partially in stock, or are available for order:
| 65µm | 80µm | 100µm |
|---|
Additional information:
- Metal Core PCBs
- Standard layer buildup
- Flex-, Rigid-Flex-, Metal Core- sample layer buildups
- Material data sheets