Prepregs, cores, foils

Printed Circuit Board Prepreg

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:

TypeTypical thicknessAfter pressing*
Type1080Typical thickness75µmAfter pressing*approx. 70µm
Type2116Typical thickness120µmAfter pressing*approx. 115µm
Type7628Typical thickness190µmAfter pressing*approx. 180µm

The following FR4 prepregs are partially in stock, or are available for order:

TypeTypical thicknessAfter pressing*
Type106Typical thickness60µmAfter pressing*approx. 55µm
Type2125Typical thickness105µmAfter pressing*approx. 100µm
Type2165Typical thickness160µmAfter pressing*approx. 150µm

* Prepreg thicknesses after pressing, at approx. 80% copper utilization on the inner layers.

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.

Multi-CB normally has the following circuit boards cores in stock*:

ThicknessCopper thickness
Thickness50µmCopper thickness18µm/18µm;
Thickness100µmCopper thickness18µm/18µm; 35µm/35µm
Thickness150µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness200µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness300µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm;
Thickness350µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm
Thickness400µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm
Thickness500µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm
Thickness550µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm; 210µm/210µm
Thickness600µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm;
Thickness700µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm;
Thickness800µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm; 140µm/140µm;
Thickness900mmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness1000µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness1200µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness1500µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness2000µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness2400µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;
Thickness3200µmCopper thickness18µm/18µm; 35µm/35µm; 70µm/70µm; 105µm/105µm;

*Special cores may also be pressed for a particular project.

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:

12µm18µm35µm70µm105µm210µm

The following FR4 prepregs are partially in stock, or are available for order:

65µm80µm100µm