Pre-preg is "pre-impregnated" composite fibers where a thermoset polymer matrix material, such as epoxy, is already present. B-Stage pre-preg is always stored in cooled areas since heat accelerates complete polymerization. Hence, composite structures built of pre-pregs will mostly require an oven or autoclave to cure.
I'm not very familiar with the multilayer PCB fabrication.As for the prepreg,should it be precoated in the copper? (See More)
Now I am designing my own PCB,but I want to define its prepreg thickness.I wonder that if the fabrication houses or manuafacturers have some standards for the prepreg thicknesses. (See More)