/Rigid-Flex PCB Solutions from Prototype to Production/
Rigid Flex PCB
Rigid Flex PCB is a hybrid printed circuit board that integrates rigid FR-4 sections and flexible polyimide circuits into a single, unified structure.
PCBSAIL provide end-to-end rigid flex PCB services—from DFM review and material selection to fabrication, SMT/THT assembly, and functional testing—backed by IPC Class 3 standards and advanced process control.
Rigid Flex PCB Manufacturer.
PCBSAIL is a professional rigid flex PCB manufacturer in China.
With advanced manufacturing and assembly facilities, PCBSAIL provides end-to-end rigid flex PCB solutions—from design verification and rapid prototyping to volume fabrication and turnkey assembly. Our operations are built around process control, material reliability, and strict adherence to IPC quality standards.
We serve OEMs, EMS providers, startups, and engineering teams that require high reliability, fast turnaround, and scalable manufacturing capacity.
By integrating fabrication and assembly under one system, we reduce supply-chain risk, shorten lead times, and ensure consistent product quality.
High Layer Design
PCBSAIL supports complex, high-layer-count rigid-flex PCB designs, including:
- 2 to 30-layer rigid-flex PCB stack-ups
- Flex-in-core and external flex structures
- HDI rigid-flex boards with microvias
- Buried and blind via constructions
- Asymmetrical and bookbinder stack-ups
Precision Fabrication
Our equipment enables:
- 3/3 mil trace and spacing
- Laser-drilled vias down to 3 mil
- Mechanical holes as small as 0.1 mm
- Controlled impedance within ±10%
Process Control
We use only qualified, traceable PCB materials from trusted suppliers, including:
- High-Tg FR-4 for rigid sections
- Polyimide substrates for flexible circuits
- Adhesiveless polyimide for dynamic bending applications
- Rogers laminates for RF and high-frequency designs
Feature Rigid Flex PCB.
We offer a complete portfolio of rigid-flex PCB solutions, covering a wide range of structures, materials, layer counts, and application requirements.
Rigid Flex PCB We Offer.
Single-Sided Rigid Flex PCB
This model features one copper layer in the flexible section bonded to one or more rigid FR-4 boards.
- Simple stack-up with high bend reliability
- Low manufacturing complexity
- Lightweight and cost-efficient
- Excellent flexibility for tight spaces
Double-Sided Rigid-Flex PCB
The flexible portion contains two conductive layers, connected by plated through-holes.
- Higher routing density than single-sided flex
- Stable electrical performance
- Balanced cost vs. complexity
Multilayer Rigid-Flex PCB
Multilayer rigid-flex PCBs include three or more copper layers in the flexible circuit, laminated with polyimide dielectrics and bonding films. Three or more copper layers in flexible areas
- Integrated power and ground planes
- Controlled impedance routing
- Improved EMI shielding
- High signal integrity for dense layouts
Laminated Rigid Flex PCB
Rigid and flexible sections are fully laminated into one unified structure using heat, pressure, and adhesive systems.
- Fully integrated rigid and flex sections
- No connectors or cables required
- Superior electrical continuity
- High vibration and shock resistance
- Long service life
Non-Laminated Rigid Flex PCB
Rigid boards and flex circuits are manufactured separately and connected using connectors or mechanical interfaces.
- Easier rework and replacement
- Lower initial manufacturing cost
- Reduced structural complexity
HDI Rigid Flex PCB
This model integrates laser-drilled microvias, blind vias, and buried vias to achieve extremely high routing density.
- Fine-pitch BGA / CSP support
- Ultra-high routing density
- Compact and lightweight design
Item | Unit | Rigid-Flex PCB Manufacturing Capability |
Max. Layers | L | 30 |
Max. Finished Board Thickness | mm | 4.0 |
Max. Production Size | mm | 500 × 1000 |
Min. Laser Drill Hole | mm | 0.075 |
Max. Aspect Ratio | / | 13:1 |
Min. Inner Layer Line Width / Spacing | mm | 0.04 / 0.04 |
Min. Outer Layer Line Width / Spacing | mm | 0.05 / 0.05 |
Solder Mask Registration Tolerance | mm | 0.035 |
Min. Solder Mask Bridge | mm | 0.08 |
Min. BGA Pitch | mm | 0.08 |
Single-ended Impedance (Size) | mm | 0.45 |
Single-ended Impedance Tolerance | % | ±7 |
Base Materials | / | Mid-Tg, High-Tg, Low Dk, Low Loss FR4, High-frequency materials |
Base Material Brands | / | Shengyi, TUC, ITEQ, Rogers, Panasonic, DuPont, Taiflex |
Surface Finish | / | ENIG, ENEPIG, OSP, Electroplated Gold, Electroplated Gold + ENIG, Electroplated Gold + OSP, Immersion Silver, Immersion Tin, Electroplated Tin |
Rigid-Flex + HDI | / | 3+N+3 (Prototype) |
Rigid Flex PCB Materials
Rigid-flex PCBs are built from a carefully selected combination of rigid and flexible materials. It was engineered to deliver mechanical stability, electrical reliability, and long-term performance in demanding environments. PCBSAIL uses only qualified, traceable materials that meet high-reliability manufacturing standards.
Flexible Core Material
Polyimide (PI) is the foundation of the flexible sections in rigid-flex PCBs. It is selected for its exceptional balance of thermal resistance, mechanical flexibility, and chemical stability.
Key Characteristics:
- High temperature resistance (Tg > 250 °C)
- Excellent bend endurance for dynamic and static flexing
- Stable dielectric properties
- Resistant to chemicals, moisture, and radiation
Polyimide is ideal for applications where the circuit must bend repeatedly or operate in extreme environments where long-term reliability is critical.
Rigid Core Materials
The rigid portions of a rigid-flex PCB require a stable structural backbone to support components, connectors, and vias.
FR-4 (Glass-Epoxy Laminate)
- High mechanical strength and dimensional stability
- Cost-effective and widely used
- Suitable for most rigid sections
Polyimide Rigid Laminates
- Higher thermal resistance than FR-4
- Better performance in high-temperature and harsh environments
- Reduced risk of delamination under thermal cycling
By combining FR-4 and polyimide laminates, designers can achieve the required mechanical support while meeting stringent thermal and reliability specifications without sacrificing manufacturability.
No-Flow Prepregs
No-flow prepregs are glass-reinforced resin systems specifically engineered for rigid-flex PCB lamination. Their primary function is to bond rigid and flexible layers together without resin flowing into the flexible areas.
Why no-flow prepregs matter:
- Prevents resin contamination of flex zones
- Maintains flexibility and bend reliability
- Ensures dimensional stability during lamination
No-flow prepregs are a critical and cost-significant component in rigid-flex PCB manufacturing, directly affecting yield, reliability, and long-term performance.
Conductive Layers
Copper foil forms the electrical interconnects in both rigid and flexible sections. The type and thickness of copper directly influence signal integrity, current capacity, and flex life.
Rolled-Annealed (RA) Copper
- Excellent ductility and fatigue resistance
- Grain structure aligned for bending
- Preferred for flexible and dynamic-bend areas
Electro-Deposited (ED) Copper
- Strong adhesion and fine-line capability
- Cost-effective
- Commonly used in rigid sections
Copper weight and dielectric spacing determine impedance control, signal loss, and noise performance. Precise copper selection ensures electrical performance without compromising flexibility or reliability.
Protective Layers
Coverlay (Polyimide Film)
- Primary protection for flexible circuits
- Shields copper from moisture, abrasion, and mechanical stress
- Excellent performance in high-flex and harsh environments
Flexible Solder Mask
- Photo-imaged polymer coating
- Thinner than coverlay
- Suitable for fine-pitch features and complex geometries
While both options provide insulation and protection, coverlay is generally preferred for applications requiring high wear resistance, repeated bending, or environmental durability.
Supporting Materials
Adhesives
Adhesives bond copper, polyimide, and other layers together.
Polyimide Adhesives
High thermal resistance
Ideal for aerospace, military, and high-temperature applications
Acrylic Adhesives
Better flexibility and peel strength
Suitable for consumer and industrial designs
Stiffeners
Stiffeners reinforce areas requiring mechanical stability, such as:
- Connectors
- Mounting holes
- Component-dense zones
Common Stiffener Materials:
- FR-4
- Polyimide
- Stainless steel
Stiffeners improve assembly reliability and prevent mechanical stress at critical interface points.
Rigid Flex PCB Feature
Our Rigid flex PCBs significantly reduce overall size and weight by eliminating bulky connectors, cables, and wiring harnesses. Flexible sections allow the circuit to fold and conform to the product’s enclosure, making rigid-flex technology ideal for space-constrained and lightweight electronic devices.
High Reliability
Rigid-flex PCB is designed to withstand repeated bending, vibration, and thermal cycling. Rolled annealed (RA) copper and polyimide films ensure long flex life. It makes rigid-flex PCBs ideal for applications with constant motion or tight mechanical constraints.
Enhanced Signal Integrity
Our Rigid-flex PCB shorter interconnect paths and fewer solder joints minimize signal loss, impedance discontinuities, and EMI. Controlled impedance structures and optimized copper thickness support high-speed and high-frequency signal transmission.
Wide Material Options
Our Rigid-flex PCB Supports multiple material combinations, including:
- FR4 and polyimide rigid cores
- RA or ED copper foils
- No-flow prepregs for clean lamination
- Coverlay or flexible soldermask
This flexibility allows designs to be optimized for thermal performance, flexibility, cost, or reliability.
Excellent Thermal
Polyimide materials and optimized copper distribution provide superior heat resistance and thermal stability. It is suitable for high-temperature environments and lead-free assembly processes.
Design Freedom
Flexible sections enable folding, wrapping, and three-dimensional integration within enclosures. This allows innovative product designs that are impossible with traditional rigid PCBs.
Rigid Flex PCB Manufacturing
The rigid-flex PCB manufacturing process combines rigid PCB fabrication techniques with flexible circuit processing in a tightly controlled production flow. Because rigid and flexible materials behave differently under heat, pressure, and mechanical stress, rigid-flex PCB fabrication requires precise process control, advanced equipment, and experienced engineering support.
At PCBSAIL, every rigid-flex PCB is produced under strict IPC standards to ensure mechanical durability, electrical reliability, and long-term performance.
Engineering Verification
Before production begins, our engineering team performs a comprehensive DFM (Design for Manufacturability) and DRC (Design Rule Check).
This stage includes:
- Layer stack-up validation
- Material selection review (FR-4, polyimide, Rogers, etc.)
- Bend radius and flex zone analysis
- Impedance control verification
- Via structure and HDI feasibility check
Flexible Circuit Core Fabrication
The flexible circuit portion is manufactured first using polyimide substrates. Key steps include:
- Copper-clad polyimide preparation (adhesive or adhesiveless)
- Imaging and pattern transfer
- Copper etching to form flex traces
- Flex layer inspection and dimensional control
Rigid Layer Core Preparation
Rigid sections are fabricated using FR-4 or high-performance rigid materials. This includes:
- Rigid core lamination
- Copper pattern imaging and etching
- Inner-layer AOI inspection
- Prepreg preparation for lamination
Rigid-Flex Lamination
Rigid and flexible layers are bonded into a single structure using heat, pressure, and adhesive systems. Depending on design requirements, we apply:
- Acrylic adhesive films
- Epoxy bonding films
- Polyimide hot-melt adhesives
- Adhesiveless lamination (for high-reliability designs)
Drilling
After lamination, vias and holes are formed to interconnect layers.
- Mechanical drilling for standard vias
- Laser drilling for microvias and HDI structures
- Burr and debris removal to protect flex zones
Copper Plating
All drilled holes and vias are plated with copper to establish electrical connections across layers. This process ensures:
- Reliable interlayer conductivity
- Strong via wall integrity
- Compliance with IPC Class 3 requirements
Outer Layer Imaging
Outer copper layers are patterned through photolithography:
- Photoresist application
- UV exposure using circuit artwork
- Copper etching to define final traces
- Final AOI inspection
Solder Mask
Solder mask is applied to rigid sections to:
- Protect copper traces
- Prevent solder bridging
- Improve insulation and durability
Surface Finish
Surface finishes are applied to exposed copper pads to ensure solderability and oxidation protection. Available finishes include:
- ENIG (Electroless Nickel Immersion Gold)
- OSP
- HASL
- Hard gold
- Immersion silver
Silkscreen
Component designators, polarity markings, traceability codes, and fabrication notes are printed using silkscreen or laser marking. This step supports:
- Accurate assembly
- Product identification
- Quality traceability
Electrical Testing
Each rigid-flex PCB undergoes 100% electrical testing to verify:
- Continuity
- Isolation
- Netlist accuracy
Final Inspection
Before shipment, boards are inspected for:
- Dimensional accuracy
- Layer alignment
- Surface finish quality
- Mechanical integrity in flex zones
| Item | Unit | Flex PCB |
| Max. Layers | L | 16 |
| Min. Finished Board Thickness | mm | 0.04 |
| Max. Size | mm | 500 × 2200 |
| Min. Laser Drill Hole | mm | 0.025 |
| Min. Mechanical Drill Hole | mm | 0.1 |
| Min. Line Width / Spacing | mm | 0.035 / 0.035 |
| Min. Annular Ring (Single / Double Side) | mm | 0.075 |
| Min. Annular Ring (Multilayer Inner Layer) | mm | 0.1 |
| Min. Annular Ring (Multilayer Outer Layer) | mm | 0.1 |
| Min. Coverlay Bridge | mm | 0.1 |
| Min. Solder Mask Opening | mm | 0.15 |
| Min. Coverlay Opening | mm | 0.30 × 0.30 |
| Min. BGA Pitch | mm | 0.45 |
| Single-ended Impedance Tolerance | % | ±7 |
| Base Material Type | / | Polyimide, LCP, PET |
| Base Material Brands | / | Shengyi, ITEQ, Taiflex, Newflex, Nikko, Panasonic, DuPont, Jiujiang |
| Stiffener Types | / | FR4, PI, PET, Steel, Aluminum, PSA, Nylon |
| Surface Finish | / | ENIG, ENEPIG, OSP, Electroplated Gold, Electroplated Gold + ENIG, Electroplated Gold + OSP, Immersion Silver, Immersion Tin, Electroplated Tin |
| Flex + HDI | / | 2+N+2 (Mass production) |
Rigid Flex PCB Applications
Our Rigid Flex PCBs are widely used in applications that require high reliability, compact packaging, mechanical durability, and stable electrical performance.
Defense
Rigid-flex PCBs are extensively used in aerospace and military systems where reliability under extreme conditions is critical. Typical applications
- Avionics control systems
- Flight instrumentation
- Radar and communication modules
- Guidance and navigation systems
Automotive
Rigid-flex PCBs are increasingly adopted in modern vehicles due to tight space constraints and harsh operating environments. Typical applications
- ADAS control modules
- Camera and sensor systems
- Infotainment electronics
- Battery management systems
Industrial Control
Industrial environments demand electronics that can operate reliably under mechanical stress, temperature variation, and long operating cycles. Typical applications
- Industrial controllers
- Robotics systems
- Sensors and actuators
- Embedded control modules
Medical Devices
Medical electronics require compact design, high reliability, and long service life—all strengths of rigid-flex PCB technology. Typical applications
- Diagnostic imaging equipment
- Implantable and wearable medical devices
- Patient monitoring systems
- Portable medical instruments
Consumer Electronics
Compact consumer products benefit greatly from the size and weight reduction offered by rigid-flex PCBs. Typical applications
- Smartphones and tablets
- Foldable and wearable devices
- Cameras and imaging modules
- Smart home electronics
Fast Quotation
Our professional sales and engineering teams provide fast PCB quotes and technical support. Simply send us your Gerber files, BOM, and assembly drawings, and we will respond promptly with a competitive solution.
- Gushu Tangxi Second Industrial Zone, Shenzhen
- +86 755 2335 0814
- +86 135 1078 8094
- sales@pcbasail.com
FAQ About Rigid Flex PCB?
1. What Is A Rigid Flex PCB?
A rigid flex PCB is a hybrid printed circuit board that combines rigid PCB sections (such as FR-4) with flexible circuits (typically polyimide) into a single integrated structure. It eliminates connectors and cables, improving reliability, reducing size and weight, and enabling complex 3D designs.
2. Are Rigid-Flex PCBs More Reliable Than Traditional PCBs?
Yes. By eliminating connectors, solder joints, and wiring harnesses, rigid-flex PCBs reduce common failure points. Their flexible sections absorb vibration and mechanical stress, making them more reliable in dynamic and harsh environments.
3. What Materials Are Used In Rigid Flex PCBs?
Rigid-flex PCBs typically use:
- Rigid materials: FR-4, high-Tg FR-4, BT resin
- Flexible materials: Polyimide (PI), PET (cost-sensitive designs)
- Copper: Rolled annealed (RA) for flex zones, electro-deposited (ED) for rigid areas
- Adhesives: Acrylic, epoxy, or adhesiveless constructions
4. What Is The Difference Between Adhesive And Adhesiveless Rigid-Flex PCBs?
- Adhesive-based designs use bonding films to laminate layers and are more cost-effective.
- Adhesiveless rigid-flex PCBs offer better heat resistance, lower CTE, improved flexibility, and higher long-term reliability—ideal for aerospace, medical, and high-reliability applications.
5. How Many Layers Can A Rigid-Flex PCB Have?
Rigid flex PCBs typically range from 2 to 30 layers, depending on design complexity. Multilayer structures can support controlled impedance, power planes, HDI features, and high-speed signals.
6. Can Rigid Flex PCBs Support Controlled Impedance?
Yes. Controlled impedance routing is supported, typically within ±10% tolerance, making rigid-flex PCBs suitable for high-speed digital, RF, and sensitive signal applications.
7. What Is The Minimum Bend Radius For Rigid Flex PCBs?
The minimum bend radius depends on:
- Number of flex layers
- Copper thickness
- Material type (adhesive vs adhesiveless)
- Static or dynamic bending requirements
PCBSAIL provides bend-radius analysis during DFM review to ensure reliability.
8. Are Rigid Flex PCBs Suitable For Dynamic Bending?
Yes, when designed correctly. Dynamic flex applications require:
- Rolled annealed copper
- Proper bend-zone design
- Adhesiveless or high-performance adhesive systems
These designs support repeated bending without cracking or signal failure.
Dynamic flex designs are commonly used in hinges, robotics, and camera modules.
9. Are Rigid Flex PCBs More Expensive Than Rigid PCBs?
The fabrication cost is higher than standard rigid PCBs. However, rigid-flex PCBs often reduce total system cost by:
- Eliminating connectors and cables
- Reducing assembly time
- Lowering failure rates and maintenance costs
10. What Surface Finishes Are Available For Rigid Flex PCBs?
Common surface finishes include:
- ENIG
- OSP
- HASL
- Hard gold
- Immersion silver
Finish selection depends on assembly method and reliability requirements.
11. Do You Provide Turnkey Rigid-Flex PCB Assembly?
Yes. PCBSAIL offers one-stop turnkey services, including PCB fabrication, component sourcing, assembly, and testing.
12. What Files Are Required To Manufacture Rigid Flex PCBs?
Commonly required files include:
- Gerber or IPC-2581 files
- Stack-up details
- Drill files
- BOM and pick-and-place files (for PCBA)