Typical Build-up ( Flexible PCB )

Single Sided Flex PCB

A single sided flexible printed circuit construction with a polyimide cover film laminated to copper allowing access from one side only. One single conductive layer, either bonded between two insulating lamination or uncovered on one side.

Single Side Double Access

Applied with single sided material to make pattern but make some window on base film and add on cover layer on pattern top. The final products will have single layer copper but two side access possibility. This structure we call that single side double access boards.

Double Sided FPC Structure

Double sided flexible circuit consist of double-sided copper clad material with top and bottom cover films (PI or Green/Yellow Oil, etc).  Two conductive layers with an insulating layer between, plus convert layers on outer layer. The cover films are pre-routed to access copper from both sides using plated thru holes (PTH).