Rigid-flex PCBs
Rigid-flex PCBs
About Rigid-Flex PCB
Rigid-flex PCBs are new creative types of PCBs that own the convenience of rigid PCBs and the high flexibility and adaptability of flexible PCBs. Among all PCBs, rigid-flex can withstand seriously tough application environments, which is favored by high-end industrial control and the medical industry. Rigid-flex PCBs differ from the original flex board and rigid board in raw material and manufacturing processes. Rigid-flex PCBs own the advantage of both rigid FR4 PCBs and flexible PCBs. In the rigid space, where electrical and electronic components will be soldered on, the whole board can bend in the flexible PCB space. That is to make the assembly more flexible and space-saving and keep tight trace designing.
Advantages of Rigid-Flex PCBs
The benefits of Rigid-Flex PCBs are below:
Save space and weight by applying 3D and removing connectors
Assure higher reliability with fewer solder joints
Simplified assembly and test processes.
Provide simple modular interfaces to the system environment.
Adapt to more complexity of mechanical designs
The disadvantage of the rigid-flex PCBs is that: the manufacturing process is complex with a low yield ratio, higher unit price, and longer lead time.
Applications of Rigid-Flex PCBs
Consumer electronics
Mainly high-end consumer electronics products for 3D connections, such as folding mobile phones, notebooks, camera modules, radio frequency modules, etc.
Automotive electronics
Rigid-Flex PCBs are commonly applied to build physical connections among variant functions of the unit, like the main control board and the control button of the steering wheel, the touch panel, the rear seat control panel, the video system screen, the vehicle communication system, satellite navigation, and vehicle exterior detection system, etc.
Equipment
For the link and signal transmission between different functional boards in the device, the circuit boards must ensure high reliability, high precision, low impedance loss, complete signal transmission quality, and durability.
Our Rigid-Flex PCB
Layers: 6(2+2+2) L Thickness: 1.0mm
Out Layer Copper Thickness: 1 OZ
Inner Layer Copper Thickness: 1 OZ
Min Hole Size: 0.2mm Min Line Width/: 3mil
Surface Finish: ENIG
Application: TWS
Layers: 12(4+4+4) L Thickness: 1.8mm
Out Layer Copper Thickness: 1 OZ
Inner Layer Copper Thickness: 1 OZ
Min Hole Size: 0.3mm Min Line Width: 4mil
Surface Finish: ENIG
Application: Home Appliance
Layers: 12(5+2+5) L Thickness: 1.6mm
Out Layer Copper Thickness: 1 OZ
Inner Layer Copper Thickness: 1 OZ
Min Hole Size: 0.25mm Min Line Width: 3.5 mil
Surface Finish: ENIG
Application: Industrial Control
What are the difficulties in making rigid-flex PCBs?
FPC part
PCB production equipment makes flexible boards. Due to the material of the flexible PCB being too soft and thin, it is easy to scrap in the manufacturing process, so it is necessary to use a traction board to pass all the horizontal lines.
Press the PI cover film. The PI cover film should be attached locally, and the pressure parameters must be controlled well. During fast pressing, the pressure should reach 2.45MPa, and it should be flat and compacted, and there should be no issues like bubbles and voids.
Rigid board part
The rigid board adopts controlled depth milling to open the window, and the PP adopts NO-FLOW PP to prevent excessive glue overflow during pressing.
The expansion and contraction control
Due to the flexible board’s poor expansion and shrinkage stability, it is crucial to prioritize the production of the flexible board and the laminated PI cover film in advance and to make the rigid board part according to its expansion and shrinkage coefficient.
Eashub’s capability on Rigid-Flex PCBs
| Feature | Capability |
| Quality Grade | Standard IPC 2, IPC 3 |
| Number of Layers | 2 – 24layers |
| Material | FR4/PTFE/R-F |
| Max Board Size | Max 450mm x 540mm |
| Final Board Thickness | 0.25mm – 5.0mm |
| Copper Thickness | 0.5oz – 2.0oz |
| Min Tracing/Spacing | 3mil/3mil |
| Min Hole Diameter – Mechanical | 6mil |
| Min Hole Diameter – laser | 3mil |
| Solder Mask Color | Green, Red, Yellow, Blue, White, Black, Purple, Matte Black, Matte green |
| Silkscreen Color | White, Black, Yellow |
| Surface Treatment | HASL, Hard Gold Finger, OSP, Immersion Gold, Immersion Tin, Immersion Sliver |
| Impedance control | ±10% |
| Lead Time | 2 – 28days |
