T
treez
Guest
Hello,
I am doing a 4 layer PCB.....(central FR4 core and outer prepreg layers).
How do they put the copper on the top and bottom layers.....i mean does the prepreg "card" come precoated with copper , and then they dissolve the unwanted copper off it?......or do they have to somehow coat the prepreg with the copper traces and pads etc?
....i am asking because if the latter, then that would mean that having copper pours on the prepreg copper would be expensive.....because the copper would all need to be actively coated on there...............as opposed to with FR4 cards, where they come pre-coated with copper and so having a copper pour is actually cheaper because it means less etchant is needed to dissolve away the unwanted copper.
I am doing a 4 layer PCB.....(central FR4 core and outer prepreg layers).
How do they put the copper on the top and bottom layers.....i mean does the prepreg "card" come precoated with copper , and then they dissolve the unwanted copper off it?......or do they have to somehow coat the prepreg with the copper traces and pads etc?
....i am asking because if the latter, then that would mean that having copper pours on the prepreg copper would be expensive.....because the copper would all need to be actively coated on there...............as opposed to with FR4 cards, where they come pre-coated with copper and so having a copper pour is actually cheaper because it means less etchant is needed to dissolve away the unwanted copper.