Rigid flexible printed circuit boards
Technologically, a distinction is made here between symmetrical and asymmetrical structures, the asymmetric solution being the more cost-effective.
The advantages of asymmetric rigid flex PCBs:
Reliable connection between flexible and rigid areas
High dynamic and mechanical load capacity
Cost savings in assembly and assembly
No manual soldering, since connectors and cables are eliminated
Simple layout design
In the rigid area, all commercially available FR4 materials (TG135, TG150, TG180) can be used. In the flexible region, one-sided or double-sided polyimide films are preferably used.
These flex materials differ in polyimide thickness, adhesive systems and copper overlays.
For copper overlays, a distinction must be made between ED and RA copper.
The advantages of symmetrical rigid flex PCBs are equal to the asymmetrical but in addition:
Higher flexibility and resilience
Higher number of layers in the flex area
Flexible base material
Polyimide with acrylic adhesive for dynamic applications
Polyimide with epoxy adhesive for static applications
Polyimide adhesiveless for high dynamic applications
15 μ, 25 μ, 50 μ and 75 μ plus glue and copper coating
Composite adhesive layer
20 μ per side
Copper supports one-sided and double-sided in 12 μ, 18 μ, 35 μ, 70 μ
ED copper for static applications with few bending cycles
RA copper for dynamic applications
Acrylic adhesive system
Protective films and paints
Coverlays made of acrylic
Coverlays of epoxy
Photo-structurable flexible solder mask