Substrate is manufactured from thin sheets of a dielectric material bonded to a sheet of electrically conductive material. illustrates the first three steps of circuit board fabrication.
Substrate is manufactured from thin PCB sheets of a dielectric material bonded to a sheet of electrically conductive material. illustrates the first three steps of circuit board fabrication.
FR4 is the most common substrate used in printed circuit boards. Epoxy resin is used to bond fiberglass to copper foil in the creation of FR4. A fire retardant is added so the PCB substrate can be safely soldered in later Processes. Some other PCB substrates are:
· polyimide/fiberglass, which can sustain higher temperatures and is much PCB harder than FR4
· FR2-fire retardant coated phenolic/paper, which is cheap and used mainly in low cost consumer electronics
· Flex circuits, usually polyimide, in some PCB cases polyester, used in automotive and other applications where space and weight are at a premium. New technology allows adhesiveless material for even PCB thinner flex circuits.
Problems that occur during substrate PCB production usually have little impact on solderability during SMT assembly.
