Rigid flex PCB manufacturer · Rigid-flex circuit boards
Rigid-Flex PCB Manufacturer: Rigid Flex Circuit Boards Built to Bend
Rigid multilayer sections and polyimide flex circuits laminated into one board. Our engineers check bend zones, transitions and stack-up against how the board actually moves in your product.
- Rigid layers (up to)
- 20
- Flex layers (up to)
- 4
- Polyimide flex core
- 25–100 µm
- Impedance in rigid & flex
- ±8%
What is a rigid-flex PCB
One board instead of boards, cables and connectors.
A rigid-flex PCB combines rigid multilayer sections and flexible polyimide circuits in one laminated board, with copper running continuously from rigid area to flex zone. It replaces board-to-board connectors and cables, which saves space and weight and removes common interconnect failure points.
The rigid sections carry components and mounting features. The flex sections fold to fit a three-dimensional enclosure, or move during operation. Only the layers that must pass between rigid areas continue through the flex, so a design may use 8–12 rigid layers but only 2 layers in the flex zone.
As a rigid flex PCB manufacturer, AstroPCB starts DFM from the mechanical use case: where the board bends, how far, how often and in which direction. Then we confirm that the copper, coverlay, stiffeners and rigid-to-flex transitions support it.
- Fewer connectors and cables, so fewer intermittent failures under vibration
- Smaller, lighter packaging and three-dimensional fit
- Simpler assembly, with no cable harness to build and plug
A rigid flex circuit board: two rigid multilayer sections joined by one polyimide flex circuit, with no connectors or cables.
Why AstroPCB
Why choose AstroPCB as your rigid flex PCB manufacturer.
A rigid flex PCB manufacturer has to understand the mechanics as well as the circuit. We review bend radius, rigid-to-flex transitions, stiffeners and coverlay against how your rigid flex circuit board actually moves before it is built.
- Up to 20 rigid and 4 flex layers, bonded or air-gap, adhesiveless or adhesive-based
- Bend and transition review included with every rigid-flex quote
- Engineering since 2008: 1,000+ engineers and 30+ partner factories in Shenzhen, Xi’an, Chengdu and Hangzhou
- Written DFM review on every order, prototype or production, before fabrication starts
- 99.6% on-time delivery across the partner factory network
- From 1 piece to volume with the same stack-up and process controls
- IPC Class 2 by default, Class 3 on request, with inspection records and batch traceability
- Fabrication plus assembly: component sourcing, SMT and tracked worldwide shipping
Rigid-flex PCB capabilities
Published rigid-flex manufacturing capabilities.
Every rigid-flex quote includes an engineering review of bend radius, rigid-to-flex transitions and stack-up feasibility.
| Parameter | AstroPCB capability |
|---|---|
| Rigid layer count | Up to 20 layers |
| Flex layer count | Up to 4 layers |
| Flex core (polyimide) | 25 to 100 µm |
| Flex construction | Adhesiveless and adhesive-based laminates; bonded or air-gap (unbonded) flex layers |
| Flex copper | Rolled-annealed (RA) copper for dynamic flex; ED copper for static designs |
| Flex protection | Polyimide coverlay; flexible solder mask where fine openings are needed |
| Stiffeners | FR-4, polyimide and stainless steel |
| HDI in rigid sections | Microvias and via-in-pad, up to 7-step HDI reviewed per design |
| Min. line / space | 50 / 50 µm |
| Controlled impedance | ±8% in rigid and flex zones with confirmed stack-up |
| Surface finishes | ENIG, ENEPIG, immersion silver, immersion tin, OSP, hard gold |
| Acceptance standard | IPC-6013 Class 2 by default, Class 3 on request |
Rigid-flex constructions
Pick the construction for how the circuit moves.
Static (flex-to-install)
The flex zone is bent once, or a few times, during assembly and then stays put. This allows more flex layers, ED copper and tighter bend ratios, and it is the most cost-effective rigid-flex construction.
Dynamic flex
The flex zone moves during operation, as in hinges, print heads or moving sensors. Use 1–2 flex layers of rolled-annealed copper on the neutral axis, generous bend radius, and no plated holes in the bend area.
Air-gap (unbonded) flex
Multiple flex layers are left unbonded to each other in the flex zone, so each bends independently. Use it when a design needs more than two flex layers but must stay flexible.
Rigid-flex design guidelines
Rules that prevent cracked copper and delamination.
Bend radius is usually given as a multiple of the total flex thickness. Commonly used IPC-2223 starting ratios are:
| Flex construction | Static bend | Dynamic bend |
|---|---|---|
| Single-layer flex | ≈ 6× thickness | ≈ 100× thickness |
| Double-layer flex | ≈ 12× thickness | Avoid where possible |
| Multilayer flex (3+ layers) | ≈ 24× thickness | Not recommended |
- Route traces perpendicular to the bend line and use curved, not sharp-angled, corners in flex areas.
- Stagger traces on two-layer flex so conductors on top and bottom do not overlap (avoids the “I-beam” effect).
- Keep vias, pads and plated holes out of bend zones, and keep plated holes clear of the rigid-to-flex transition (a common starting rule is about 1.3 mm / 50 mil).
- Use hatched ground planes in flex zones that must stay flexible, and account for them in impedance calculations.
- Add teardrops and anchoring spurs on flex pads to resist peeling.
- Show the bend in the drawing: location, direction, angle, radius and static or dynamic use.
More detail in our rigid-flex PCB design guide.
The rigid-to-flex transition is the highest-stress area of the board.
Rigid-flex materials
Materials for rigid sections, flex zones and the bond between them.
Polyimide flex laminates
Adhesiveless polyimide offers thinner builds, better dimensional stability and higher temperature performance. Adhesive-based laminates remain a cost option for static designs.
Polyimide materialRigid sections
High-Tg FR-4 for most designs, with low-loss laminates where rigid sections carry high-speed channels. No-flow or low-flow prepreg controls resin squeeze-out at the transition.
FR-4 material guideCoverlay & stiffeners
Polyimide coverlay protects flex copper. FR-4, polyimide or stainless steel stiffeners support connectors, ZIF tails and components on flex areas.
Polyimide PCB guideWhere rigid-flex is used
Industries that rely on rigid-flex circuit boards.
Medical devices
Wearable monitors, handheld diagnostics and imaging probes, where size, weight and reliability set the design.
Medical PCB
Aerospace & defense
Avionics, satellite and rugged handheld electronics that must survive vibration without connector failures.
Aerospace & defense PCB
Industrial, automotive & consumer
Camera modules, sensors, robotics joints and folding consumer devices.
Automotive PCBQuality & verification
How rigid-flex boards are verified.
Rigid-flex boards get more inspection than rigid boards because their main failure modes, cracked copper in the bend and delamination at the transition, are mechanical.
- Written DFM review of bend radius, transition and stack-up
- AOI of rigid and flex layers
- 100% electrical test (flying probe or fixture)
- TDR impedance testing on rigid and flex coupons
- Microsection analysis of plated holes and the transition
- IPC-6013 Class 2 or 3 acceptance; flex endurance testing when specified
Need assembled boards? See rigid-flex PCB assembly.
Rigid-flex PCB cost
What drives rigid-flex PCB cost.
A rigid-flex board often costs several times as much as a rigid board of the same size. Compare it instead with the full assembly it replaces: rigid boards, connectors, cables and the labor to build and test them. For many products, total system cost and field reliability favor rigid-flex.
- Flex layer count and bonded vs air-gap construction
- Rigid layer count and HDI in rigid sections
- Panel utilization: rigid-flex outlines nest less efficiently than rectangles
- Adhesiveless vs adhesive-based polyimide
- Stiffeners, coverlay openings and selective finishes
- Impedance control through flex zones
- Quantity and inspection class
Rigid-flex outlines are routed free of the panel and held by breakaway tabs, so fewer boards fit per panel than rectangular designs.
Send your files and bend drawing. Our quote points out where a simpler construction meets the same mechanical requirement.
Request a rigid-flex quote
What to include in your rigid-flex RFQ.
- Gerber, ODB++ or IPC-2581 data (IPC-2581 carries zone-based stack-ups well)
- Rigid and flex stack-ups with material intent
- Bend drawing: location, direction, angle, radius
- Static or dynamic use and any required flex cycles
- Stiffener material, thickness and location
- Coverlay openings, connector and ZIF tail details
- Impedance-critical nets in rigid and flex zones
- IPC class, finish, quantity and assembly needs
FAQ
Rigid-flex PCB questions, answered.
What is a rigid-flex PCB?
A rigid-flex PCB combines rigid multilayer sections and flexible polyimide circuits in one laminated board, with copper running continuously between them. It replaces connectors and cables between separate boards.
How many layers can a rigid-flex PCB have?
AstroPCB manufactures rigid-flex boards with up to 20 rigid layers and up to 4 flex layers. A typical construction uses 4–12 rigid layers with 1–2 layers through the flex zone.
What is the minimum bend radius for a rigid-flex PCB?
Common IPC-2223 starting points for static bends are about 6× the flex thickness for single-layer flex, 12× for double-layer and 24× for multilayer flex. Dynamic flexing needs about 100× with single-layer, rolled-annealed copper. Your construction is confirmed during DFM.
What is the difference between static and dynamic flex?
Static (flex-to-install) circuits bend once or a few times during assembly. Dynamic circuits flex repeatedly in operation, which calls for fewer flex layers, rolled-annealed copper and a larger bend radius.
Rigid-flex vs flex PCB with connectors: which is better?
Rigid-flex removes connectors, cables and assembly steps, so it improves reliability and saves space and weight, but the bare board costs more. A flex circuit plugged into rigid boards is cheaper per board and easier to rework. See also our flex PCB service.
Can you assemble rigid-flex PCBs?
Yes. Components are placed on the rigid sections, or on stiffened flex areas. AstroPCB offers rigid-flex fabrication plus component sourcing and SMT and through-hole assembly as a turnkey service.
What standards do your rigid-flex boards meet?
Rigid-flex boards are built and accepted to IPC-6013, Class 2 by default and Class 3 on request, with design guidance from IPC-2223.
How do I get a rigid-flex PCB quote?
Upload your fabrication data, stack-up and bend drawing on the quote page. Every rigid-flex quote includes a written DFM review, typically within one business day.
Ready when your files are
Send your rigid-flex design and bend drawing for review.
Upload Gerber, ODB++ or IPC-2581 data. Every quote includes a written engineering DFM review, typically within one business day.