Rigid-flex boards are PCBs that have Flexible PCBs (FPC) and Rigid PCBs on the same board, which are commonly employed to save space, remove wiring assemblies and can also be welded with complex components. Combining other higher technology boards, such as HDI, as a part of its packaging, is also a common design.
Rigid-flex with 2-16L rigid board and 1-6L flex board
Air gap structure on flexible area
Rigid-flex PCB with 2-step HDI
Rigid-flex with asymmetric structure (1 flexible layer + 1 rigid layer)
Dispensing on rigid flex transition area