When working on the Rigid-Flex PCB Layer stack-up, an essential factor to consider is the stresses that flex board experiences due to bends and curves of the PCB.
So, use these 4 tips to help you create a stack-up for a robust rigid-flex PCB:
1. Keep the flexible section symmetrically in the center of the rigid PCB layers.
2. When routing traces on flexible sections of the PCB, make sure that the traces are running perpendicular to any bending lines. This ensures that the copper does not fatigue and wear out early.