Flex PCB Capability
Flexible PCB Manufacturing Capabilities
APTPCB is a professional PCB manufacturer providing flexible PCB (FPC) solutions for compact and lightweight electronic products such as consumer devices, wearable electronics, automotive modules, and medical equipment. We manufacture 1–16 layer flex PCBs with polyimide, PET, PEN, and FR-4 base films, supporting bend-radius optimization and dynamic flex applications.
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Flex PCB Manufacturing Capabilities – APTPCB
APTPCB is a professional PCB manufacturer and assembler, providing flexible PCB (FPC) solutions for compact and lightweight electronic products such as consumer devices, wearable electronics, automotive modules and medical equipment.
We can work with almost all common PCB engineering data formats, including design files from mainstream PCB design software such as Altium Designer, Cadence Allegro and OrCAD, Mentor Xpedition and PADS, KiCad, Protel and others. For mass production, we recommend sending standard Gerber and drill files (and, where available, ODB++ or IPC-2581) as the final manufacturing data to ensure maximum accuracy.
Flex PCB Capability Overview for PCB Designers
The capability table below summarizes APTPCB’s standard manufacturing window for flexible PCBs. It lists the typical ranges for layer count, materials, thickness, line width/spacing, copper thickness, drilling, surface treatment and profile tolerance. PCB designers can use these values as a direct reference when defining design rules and stack-ups in their CAD tools.
If your flex design is close to these limits, or you need special constructions (e.g. very thin or very thick flex, unusual material combinations, special stiffeners or specific finish thicknesses), please send your preliminary files and requirements to our engineering team. We will check feasibility, highlight risk points and suggest practical adjustments where needed.
Flex PCB Manufacturing Capabilities
| Item | Description |
|---|---|
| Layer | Flexible board: 1–16 layers (for standard flex applications); rigid-flex and higher layer counts are handled on a separate capability page |
| Materials (base film) | PI (polyimide), PET, PEN, FR-4, DuPont polyimide and other specified materials on request |
| Stiffeners | FR-4, aluminum, polyimide, stainless steel stiffeners available according to design requirements |
| Final Thickness | Flexible board: 0.002″ – 0.10″ (0.05 – 2.5 mm) |
| Surface Treatment (lead-free) | ENIG (gold), OSP, immersion silver, immersion tin; other finishes on request |
| Max / Min Board Size | Min: 0.2″ × 0.3″; Max: 20.5″ × 13″ (panelized) |
| Min Trace Width / Min Clearance – inner layers | 0.5 oz copper: 4 / 4 mil; 1 oz: 5 / 5 mil; 2 oz: 5 / 7 mil |
| Min Trace Width / Min Clearance – outer layers | 1/3 oz – 0.5 oz copper: 4 / 4 mil; 1 oz: 5 / 5 mil; 2 oz: 5 / 7 mil |
| Min Hole Ring – inner layers | 0.5 oz: 4 mil; 1 oz: 5 mil; 2 oz: 7 mil |
| Min Hole Ring – outer layers | 1/3 oz – 0.5 oz: 4 mil; 1 oz: 5 mil; 2 oz: 7 mil |
| Copper Thickness (flex area) | 1/3 oz – 2 oz (thinner or thicker copper on request after engineering review) |
| Max / Min Insulation Thickness | Max: 2 mil (50 μm); Min: 0.5 mil (12.7 μm) |
| Min Hole Size and Tolerance | Min finished hole size: 8 mil; PTH tolerance: ±3 mil; NPTH tolerance: ±2 mil |
| Min Slot | 24 mil × 35 mil (0.6 × 0.9 mm) |
| Solder Mask / Coverlay Alignment Tolerance | ±3 mil |
| Silkscreen (legend) Alignment Tolerance | ±6 mil |
| Silkscreen Line Width | 5 mil minimum |
| Gold Plating (hard gold / gold fingers) | Nickel: 100 μ″ – 200 μ″; Gold: 1 μ″ – 4 μ″ |
| Immersion Nickel / Gold (ENIG) | Nickel: 100 μ″ – 200 μ″; Gold: 1 μ″ – 5 μ″ |
| Immersion Silver | Silver thickness: 6 μ″ – 12 μ″ |
| OSP | Film thickness: 8 μ″ – 20 μ″ |
| Test Voltage | Electrical testing (fixture): 50 – 300 V according to customer specification |
| Profile Tolerance of Punch – accurate mould | ±2 mil |
| Profile Tolerance of Punch – ordinary mould | ±4 mil |
| Profile Tolerance of Punch – knife mould | ±8 mil |
| Profile Tolerance of Punch – hand-cut | ±15 mil |
Design Notes and Early Communication for Flex PCB Projects
Compared with standard rigid boards, flex PCBs are more sensitive to layer stack-up, material choice and mechanical conditions. Bend radius, copper thickness and trace routing in bending areas all influence lifetime and reliability, especially in dynamic applications.
When you design a flex PCB, we recommend that you:
- avoid placing vias, pads and sharp copper corners directly in dynamic bend regions,
- choose copper thickness and insulation thickness according to the required bend radius,
- keep copper balanced across the width of the flex area to reduce stress, and
- confirm that stiffener type, thickness and outline are compatible with your connectors and assembly process.
If you share your preliminary stack-up, mechanical drawing and PCB data with APTPCB at the early stage, our engineering team can perform a focused DFM review specifically for your flex design. This helps prevent cracking or delamination in bend areas, reduces the chance of late design changes and ensures that the final product can be manufactured reliably within the capability ranges listed above.
Frequently Asked Questions
What materials are used for flex PCBs?
We support polyimide (PI), PET, PEN, and FR-4 base films. Polyimide is most common for high-reliability designs due to thermal stability and flexibility.
What is the minimum bend radius for flex PCBs?
It depends on material and thickness. Typical guidance is 5–10× board thickness; we’ll recommend a safe radius for your stack-up.
Can flex PCBs handle dynamic flexing?
Yes. With proper copper/coverlay choices and trace routing, polyimide-based flex can endure thousands to millions of cycles.
What surface finishes are available?
ENIG, OSP, immersion silver, and immersion tin are supported; we’ll match finish to your assembly and reliability needs.
Do you support controlled impedance on flex PCBs?
Yes. We align stack-up and TDR validation to meet impedance targets on flex builds.
Partner with APTPCB for Flexible PCB Solutions
If your flex design is close to capability limits or requires special constructions (very thin/thick flex, unusual material combinations, special stiffeners), our engineering team will check feasibility, highlight risk points, and suggest practical adjustments.