Flexible Design Solutions
1–16 layer flex PCBs optimized for compact, lightweight applications in consumer devices, wearables, automotive modules, and medical equipment.
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 Capability Overview
APTPCB specializes in flexible PCB manufacturing for compact and lightweight electronic products across multiple industries.
Material Flexibility
Support for polyimide (PI), PET, PEN, FR-4, and other specified materials with stiffeners (FR-4, aluminum, polyimide, stainless steel).
Design Support
Early-stage DFM review to prevent cracking or delamination in bend areas and ensure reliable manufacturing.
Multiple File Formats
Support for Altium Designer, Cadence Allegro, OrCAD, Mentor Xpedition, PADS, KiCad, and standard Gerber/ODB++/IPC-2581 formats.
Flex PCB Manufacturing Capabilities
| Item | Description | Notes |
|---|---|---|
| Layer Count | 1–16 layers (standard flex); rigid-flex and higher layer counts handled separately | Flexible board standard range |
| Base Materials | PI (polyimide), PET, PEN, FR-4, DuPont polyimide, and other specified materials | Material selection per design requirements |
| Stiffeners | FR-4, aluminum, polyimide, stainless steel stiffeners available | According to design requirements |
| Final Thickness | 0.002″–0.10″ (0.05–2.5 mm) | Flexible board thickness range |
| Surface Treatment | ENIG (gold), OSP, immersion silver, immersion tin; other finishes on request | Lead-free options |
| Max / Min Board Size | Min: 0.2″ × 0.3″; Max: 20.5″ × 13″ (panelized) | Panelized production available |
| Min Trace Width / Clearance (inner) | 0.5 oz: 4/4 mil; 1 oz: 5/5 mil; 2 oz: 5/7 mil | Copper weight dependent |
| Min Trace Width / Clearance (outer) | 1/3–0.5 oz: 4/4 mil; 1 oz: 5/5 mil; 2 oz: 5/7 mil | Copper weight dependent |
| Min Hole Ring (inner) | 0.5 oz: 4 mil; 1 oz: 5 mil; 2 oz: 7 mil | Inner layer specifications |
| Min Hole Ring (outer) | 1/3–0.5 oz: 4 mil; 1 oz: 5 mil; 2 oz: 7 mil | Outer layer specifications |
| Copper Thickness (flex area) | 1/3–2 oz (thinner or thicker on request after engineering review) | Standard copper weight range |
| Max / Min Insulation Thickness | Max: 2 mil (50 μm); Min: 0.5 mil (12.7 μm) | Insulation layer control |
| Min Hole Size & Tolerance | Min finished hole: 8 mil; PTH: ±3 mil; NPTH: ±2 mil | Drilling precision specifications |
| Min Slot | 24 mil × 35 mil (0.6 × 0.9 mm) | Minimum slot dimensions |
| Solder Mask / Coverlay Alignment | ±3 mil | Alignment tolerance |
| Silkscreen (Legend) Alignment | ±6 mil | Legend alignment tolerance |
| Silkscreen Line Width | 5 mil minimum | Legend line width specification |
| Gold Plating (hard gold / fingers) | Nickel: 100–200 μ″; Gold: 1–4 μ″ | Hard gold specifications |
| Immersion Nickel / Gold (ENIG) | Nickel: 100–200 μ″; Gold: 1–5 μ″ | ENIG surface finish |
| Immersion Silver | Silver thickness: 6–12 μ″ | Immersion silver finish |
| OSP | Film thickness: 8–20 μ″ | Organic Solderability Preservative |
| Test Voltage | 50–300 V according to customer specification | Electrical testing range |
| Profile Tolerance (accurate mould) | ±2 mil | Accurate punch mould tolerance |
| Profile Tolerance (ordinary mould) | ±4 mil | Ordinary punch mould tolerance |
| Profile Tolerance (knife mould) | ±8 mil | Knife punch mould tolerance |
| Profile Tolerance (hand-cut) | ±15 mil | Hand-cut profile tolerance |
| Typical lead time | 7–20 working days | Varies by complexity, layer count, and production volume; expedited options available |
Design Notes and Best Practices for Flex PCB
Flex PCBs are more sensitive to layer stack-up, material choice, and mechanical conditions than rigid boards. Bend radius, copper thickness, and trace routing in bending areas all influence lifetime and reliability.
Avoid Vias in Bend Regions
Avoid placing vias, pads, and sharp copper corners directly in dynamic bend regions to prevent cracking and stress concentration.
Copper & Insulation Thickness
Choose copper thickness and insulation thickness according to the required bend radius to ensure adequate flexibility and durability.
Copper Balance
Keep copper balanced across the width of the flex area to reduce stress and prevent uneven bending behavior.
Stiffener Compatibility
Confirm that stiffener type, thickness, and outline are compatible with your connectors and assembly process.
Early DFM Review
Share preliminary stack-up, mechanical drawing, and PCB data at the early stage for focused DFM review to prevent late design changes.
Flex PCB Manufacturing Process
- 1
Design Review & Intake
Collect flex PCB design files, mechanical drawings, material requirements, and bend-radius specifications. Verify compatibility with manufacturing capabilities.
- 2
Material & Stackup Planning
Select base film (PI, PET, PEN, FR-4), copper weight, insulation thickness, and stiffener type based on bend-radius and reliability requirements.
- 3
Lamination & Copper Patterning
Laminate base film with copper foil, pattern circuits, and etch traces according to design specifications and line/space tolerances.
- 4
Drilling & Hole Processing
Perform precision drilling, hole sizing, and plating to meet PTH/NPTH tolerances and copper ring specifications.
- 5
Surface Finish & Coverlay
Apply surface finish (ENIG, OSP, immersion silver/tin), apply coverlay or solder mask, and perform alignment verification.
- 6
Profile Cutting & Testing
Cut final profile using appropriate mould (accurate, ordinary, knife, or hand-cut), perform electrical testing, and validate bend characteristics.
Flex PCB Applications
Flexible PCBs are ideal for compact, lightweight applications requiring space-saving and dynamic flex capabilities.
Consumer Electronics
Smartphones, tablets, laptops, cameras, and portable devices requiring compact and flexible interconnections.
Wearable Electronics
Smartwatches, fitness trackers, medical wearables, and flexible sensors for body-worn applications.
Automotive Modules
Dashboard displays, infotainment systems, sensor modules, and flexible connectors for automotive applications.
Medical Equipment
Diagnostic devices, implantable electronics, flexible sensors, and medical wearables with biocompatibility requirements.
Industrial & IoT
Flexible interconnects for industrial equipment, IoT devices, and space-constrained applications.
Design for Manufacturability (DFM) Support
Our engineering team provides comprehensive DFM guidance to optimize your flex PCB designs for performance, reliability, and cost-effectiveness.
Early-Stage Review
Perform focused DFM review on preliminary stack-up, mechanical drawing, and PCB data to prevent cracking or delamination.
Bend-Radius Optimization
Validate bend-radius requirements, copper thickness, and insulation thickness for dynamic flex applications.
Material Selection
Guidance on base film selection (PI, PET, PEN, FR-4), stiffener type, and surface finish for your specific application.
Design Rule Definition
Help define design rules and stack-ups in CAD tools based on APTPCB's manufacturing capabilities and tolerances.
Frequently Asked Questions
What materials are used for flex PCBs?
We support polyimide (PI), PET, PEN, and FR-4 base films. Polyimide is the most common for high-reliability applications due to its thermal stability and flexibility.
What is the minimum bend radius for flex PCBs?
Minimum bend radius depends on the material and thickness. Typically, it's 5–10× the board thickness. Our engineering team will recommend the safe bend radius for your specific design.
Can flex PCBs handle dynamic flexing?
Yes, flex PCBs are designed for dynamic flexing. Polyimide-based designs can withstand thousands to millions of flex cycles depending on bend radius, copper weight, and trace routing.
What is the maximum layer count for flex PCBs?
APTPCB supports 1–16 layer flex PCBs. Multi-layer flex designs require careful stack-up planning to ensure manufacturability and reliability.
What surface finishes are available?
We offer ENIG, OSP, immersion silver, and immersion tin finishes. Surface finish selection depends on your assembly process and environmental requirements.
Can you add stiffeners to flex PCBs?
Yes, we can add FR-4, polyimide, or aluminum stiffeners to specific areas of flex PCBs to support component placement and improve mechanical stability.
What is the typical lead time for flex PCBs?
Lead times typically range from 7–20 working days depending on complexity, layer count, and production volume. Expedited options are available.
Do you support controlled impedance on flex PCBs?
Yes, we can support controlled impedance designs on flex PCBs with proper stack-up design and validation using TDR coupons.
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.