PCB Types / Flex PCB
Flexible printed circuits on polyimide substrates from 1 to 8 layers. Adhesiveless construction, laser-cut coverlay, and FR-4/PI/stainless stiffeners — for applications that must fold, bend, or fit where rigid boards cannot.
Technology Overview
Flexible PCBs (FPCs) replace traditional wire harnesses and rigid-board interconnects with thin, bendable polyimide circuits that can be folded, twisted, or dynamically flexed millions of times. Originally developed for aerospace and military applications, flex circuits now enable the miniaturization of consumer electronics, medical devices, and automotive systems.
Unlike rigid PCBs, flex circuits use a polyimide base film (typically 25-50µm) with rolled-annealed copper for superior ductility, protected by a polyimide coverlay — not solder mask. Our adhesiveless process eliminates acrylic adhesive layers that can crack during dynamic flexing.
Technical Specifications
| Number of Layers | 1 – 8 layers (single-sided, double-sided, multilayer) |
| Base Material | Polyimide (PI) 25/50/75/125µm · LCP · Teflon (PTFE) |
| Copper Type | Rolled-Annealed (RA) 12/18/35/70µm · ED copper for static applications |
| Min. Trace / Space | 3 / 3 mil (0.075 / 0.075 mm); 2/2 mil with 1/3 OZ base |
| Coverlay | 12.5 – 50µm polyimide coverlay; laser-cut apertures ±50µm |
| Min. Bend Radius | 1 mm (single-sided); 2-3 mm (double-sided); 6× board thickness rule |
| Stiffener Types | FR-4 (0.2-1.6mm) · Polyimide (0.1-0.3mm) · Stainless Steel (0.1-0.3mm) |
| Surface Finish | ENIG · ENEPIG · Immersion Ag · OSP · HASL |
| Min. Finished Thickness | 0.08 mm (single-layer); 0.2 mm (double-layer) |
| Impedance Control | ±7% (single-ended, due to variable Dk of PI) |
| Shielding | Silver ink screen-print · Copper foil laminate · Conductive PSA film |
| Quality Standard | IPC-6013 Class 2 / Class 3 · IATF 16949 · ISO 9001 |
One copper layer on polyimide with coverlay. Maximum bendability, minimum cost. Used for simple interconnects, ZIF tails, and jumper replacements.
Copper on both sides of polyimide with PTH interconnection. Good bend performance with more routing capability. Common in camera modules and display interconnects.
Multiple polyimide layers laminated with adhesiveless bonding. Higher routing density with reduced flexibility. Used in aerospace harness replacements and medical probe assemblies.
Selectively etched copper to create flexible bend areas with thicker rigid terminal ends. Ideal for one-piece connector replacements — no ZIF connector needed at assembly.
Manufacturing Process
Traditional flex PCBs use acrylic or epoxy adhesive to bond copper to polyimide — but these adhesives are the primary failure point during repeated bending. Our adhesiveless process directly casts polyimide onto copper foil or sputters a seed layer, eliminating the weak interface entirely.
Display flex, camera module, button interconnect
Dashboard flex harness, LED lighting, sensor interconnect
Ultrasound probe flex, endoscope interconnect, hearing aids
Satellite harness replacement, avionics interconnect
Smartwatch flex, fitness tracker, AR/VR headset
Dynamic flex for articulated robot joints, slip-ring replacement
Upload your flex circuit design — include bend requirements, stiffener needs, and any special coverlay openings. We'll review for manufacturability and respond within 24 hours.
Tell us layer count, bend radius, stiffener needs, and quantity. Free DFM within 24h.