Close-up of Substrate material or within rigid stackup
Sheets of copper foil, about as thin as a human hair, are then bonded to one or both sides of the substrate.
Strands of Human Hair
Sheet of ½ oz. copper thickness shown to scale/comparison with strands of hair
This copper-clad substrate can be repeatedly etched and plated to build up multiple layers of circuitry, creating a rigid board
around (60 mils) 1-2 mm thick
PCB Stackup showing standard thickness of a 4-layer PCB
5 www.cadence.com
Rigid Flex Design Guide