The double sided printed circuit boards that we offer are individual PCBs that are stepped up onto a bigger panel, tooled with fiducial marks to assist assembly and are bridged (using break out pips) or scored so boards can be freed from the panel.
It allows many PCBs to be manufactured at once and also means many PCBs can be assembled together that reduces the process time. The entire gamut is manufactured using CEM1, CEM3, FR2, and FR4, polyimide, RT duroid and PTFE.