Rigid Flex Architecture against Two Boards and a Connector
Rigid-flex architecture eliminates discrete connector failures and signal discontinuities while reducing assembly labor, justifying higher bare-board costs.
Un Bonded Flex Construction
Independent Layer Assembly
Flexible printed circuit designs where the individual polyimide trace layers are not glued together in the bending region allow for maximum movement and a tighter fold radius. Utilizing an un bonded flex construction reduces the mechanical stiffness of a multi-layer flexible board. This method is used in applications that require dynamic flexing or where the circuit must fit into highly restricted spaces.
The loose layers slide against each other during bending to prevent the copper traces from stretching and breaking.
Trace Fatigue Reduction
Solidly laminated multi-layer boards suffer high mechanical strain on the outer layers when bent. Selecting un bonded flex construction relieves this strain by allowing each layer to flex independently. This structure extends the operational lifetime of the conductors.
Fabrication Routing Difficulty
Cutting and laminating boards with unbonded regions requires precise alignment and the selective application of adhesive layers. When executing un bonded flex construction, the manufacturer must use selective lamination and laser cutting to ensure the loose layers remain clean and separate. This selective process increases the processing time but yields a highly reliable assembly.
It represents the optimal design choice for complex hinges and medical imaging devices that demand continuous movement.