What is Flexible PCB
A flexible PCB is also known as a flexible circuit board, flex PCB, FPC. Copper circuit traces are etched on the non-conductive flexible polyimide materials, and different circuit layers are interconnected by plated through holes (PTH) or buried vias. On the two sides of a flexible PCB, electronic components can be surface-mounted on the PCB pads. For better mechanical support, sometimes, PCB stiffeners can add to the ends of flexible PCBs for connection with the system/device/other parts.
flexible PCB stiffeners
Like traditional PCBs, flexible PCBs are custom designed and manufactured, and they can be single-sided, double-sided, single-layer, dual-layer, or multi-layer. One circuit layer counts one PCB layer. But flexible PCBs are so different from traditional rigid PCBs, and everyone can identify them immediately - flexible PCBs are thin, light, and usually, yellow.
And the thickness range of flexible PCBs falls within 0.05mm to 0.6mm. This is also the finished flex PCB thickness range from PCBHERO.
Flexible PCBs are usually double-sided. To better understand flexible PCBs, you need to know the basic structure of flexible PCBs.