Rigid-flex PCBs represent the ultimate integration of flexible circuit technology with traditional rigid board construction. By combining rigid FR4 areas for component mounting with flexible polyimide sections for interconnection, rigid-flex assemblies eliminate the connectors and cables that would otherwise be needed to join separate boards.
The benefits extend beyond simple connector elimination. Rigid-flex assemblies are more reliable (fewer solder joints means fewer potential failure points), more compact (flex sections fold into 3D configurations), lighter weight, and often more economical when total assembly cost is considered.
Our rigid-flex capability spans from simple 4-layer single-flex designs to complex multilayer constructions with multiple flex regions. We support both commercial and high-reliability applications with appropriate certifications and quality systems.
Replace cables and connectors with integrated flex sections. Fewer connections means higher reliability and reduced assembly cost.
Flex sections fold to enable true 3D packaging. Fit more functionality into less volume. Essential for compact product designs.
Eliminate the weight and volume of connectors and cables. Critical for portable, wearable, and aerospace applications.
Monolithic construction eliminates intermittent connection failures. Proven reliability in high-vibration and extreme environments.
Rigid-flex designs range from simple to highly complex.
Two rigid boards connected by one flex section. The most common configuration for basic board-to-board connections.
Three or more rigid areas connected by multiple flex regions. Enables complex 3D assemblies with multiple fold points.
Multiple parallel flex sections connecting two rigid boards. Provides redundancy and distributes stress across multiple flex regions.
Flex sections with varying thickness. Thinner in high-flex areas, thicker where additional copper is needed for current capacity.
Some designs place components directly on flex sections. Requires stiffeners for support and careful thermal management.
Layer count can vary between rigid and flex regions. Flex sections typically use fewer layers than rigid areas for improved flexibility.
Rigid-flex design requires attention to the unique aspects of combined construction.
Keep flex sections as simple as possible. Use fewer layers in flex (typically 1-2 for best flexibility). Route traces perpendicular to bend axis.
The transition zone between rigid and flex requires careful design. Graduated stiffener edges reduce stress concentration. Anchor pads help prevent pad lifting.
Place components only in rigid regions unless specifically designed otherwise. Keep adequate clearance from flex transition zones.
Minimize vias in flex regions. No vias within 0.5mm of flex boundaries. Use teardrop via pads in transition zones.
Balance copper on opposite sides of flex sections to prevent warping. Use hatched rather than solid planes in flex regions.
Design for the assembled bend radius from the start. Factor in material thickness, layer count, and number of bend cycles.
Rigid-flex manufacturing combines multiple PCB technologies with additional process steps.
Rigid areas typically use FR4 (Tg 170°C+ for lead-free assembly). Flex areas use polyimide. Material compatibility at interfaces is critical.
Rigid and flex layers are defined in a unified stackup. Sequential lamination may be required for complex constructions.
Rigid material is removed to create flex regions. Controlled depth routing ensures proper flex exposure without damaging flex layers.
Polyimide coverlay protects flex regions. Applied before or after rigid lamination depending on construction type.
FR4 or polyimide stiffeners support connector areas and component mounting zones on flex regions.
Electrical testing, visual inspection, and dimensional verification ensure quality. Flex life testing validates dynamic flex designs.
Compact rigid-flex assembly connecting sensor board, processor board, and display in smartwatch form factor. Folds into 3D assembly during manufacturing.
6-layer rigid-flex connecting camera head, LED illumination, and control electronics through 3mm diameter articulating section.
8-layer rigid-flex integrating IMU, GPS, radio, and power management. Rigid sections stack vertically with flex sections routing between.
Consider rigid-flex when: space is constrained, reliability is critical, 3D packaging is beneficial, or total assembly cost (including connectors and cables) favors integration. We can help analyze your specific situation.
Rigid-flex boards cost more than equivalent separate rigid boards. However, total assembly cost often favors rigid-flex when connector, cable, and labor costs are included. We provide comparative quotes.
We support rigid-flex constructions up to 20+ layers in rigid regions. Flex regions typically use fewer layers (2-4) to maintain flexibility. Complex constructions require careful stackup planning.
Yes, with appropriate design. Flex regions can be designed for dynamic flexing with proper bend radius, copper type, and layer count. We validate dynamic flex designs with life testing.
Our rigid-flex manufacturing is supported by ISO 9001, AS9100D for aerospace, and ISO 13485 for medical devices. IPC-6013 Class 2 and Class 3 workmanship standards are available.
