Flexible PCB Manufacturing: Complete Guide to Flex & Rigid-Flex Boards

Published June 10, 2026 · By Mayio Engineering Team · 8 min read

Flexible PCBs are everywhere — in your phone, your smartwatch, your earbuds, your car's dashboard. If your product needs to bend, fold, or fit into a tight space, a flex PCB is probably what you need. This guide covers everything: materials, types, pricing, design rules, and how to get them manufactured.

What Is a Flexible PCB?

A flexible PCB (flex PCB) is a circuit board built on a flexible substrate instead of rigid FR4. It can bend, fold, and conform to 3D shapes. The most common flexible substrate is polyimide (Kapton) — the same material used in spacecraft insulation.

✅ Advantages of Flex PCB

Bends and folds to fit any shape
Lighter than rigid boards
Higher reliability (fewer connectors = fewer failure points)
Thinner profile
Better vibration resistance

❌ Disadvantages of Flex PCB

2-5x more expensive than rigid
Harder to design (bend radius rules)
More fragile during handling
Fewer manufacturers can make them well
Assembly requires more care

Types of Flexible PCBs

Type	Description	Use Case
Single-layer flex	1 copper layer on polyimide	Simple interconnects, displays
Double-layer flex	2 copper layers on polyimide	USB cables, sensor arrays
Multi-layer flex	3+ copper layers on polyimide	Complex flex circuits
Rigid-Flex	Flex layers bonded between rigid boards	Phones, wearables, medical devices
PCB stiffer	Flex board with localized stiffeners	Connector areas, mounting points

Flex PCB Materials

Material	Temperature Range	Cost	Best For
Polyimide (Kapton)	-269°C to +400°C	Standard	Most flex applications
PET (Polyester)	-70°C to +150°C	Cheaper	Low-temp, cost-sensitive
PEEK	-260°C to +260°C	Expensive	Aerospace, medical

Polyimide is the industry standard. It handles lead-free soldering temperatures, has excellent chemical resistance, and is widely available. Unless you have a specific reason to use something else, go with polyimide.

Flex PCB Pricing

Type	5pcs	10pcs	50pcs	Lead Time
Single-layer flex	$8.00	$15.00	$50.00	5-7 days
Double-layer flex	$12.00	$22.00	$80.00	7-10 days
4-layer rigid-flex	$25.00	$45.00	$160.00	10-14 days
Multi-layer flex (6+)	Quote	Quote	Quote	14-21 days

Note: Flex PCB pricing depends heavily on the number of bend zones, stiffener requirements, and coverlay specifications. Send your Gerber files for an accurate quote — the table above is for standard configurations.

Flex PCB Design Rules

1. Respect the Bend Radius

The minimum bend radius depends on the number of copper layers and the total thickness:

Single-layer: Minimum bend radius = 6× board thickness
Double-layer: Minimum bend radius = 10× board thickness
Multi-layer: Minimum bend radius = 15× board thickness

Example: A 0.1mm thick single-layer flex board can be bent to a 0.6mm radius. Tighter than that and the copper cracks.

2. Route Traces Perpendicular to Bend Lines

Traces that run parallel to the bend direction are under maximum stress. Route them perpendicular instead. Use curved corners, not 90° angles.

3. Use Hatched Copper Pours

Solid copper pours crack when bent. Use hatched (grid) patterns instead. This allows the copper to flex without fracturing.

4. Add Stiffeners Where Needed

Connector areas and component mounting points need to be rigid. Specify stiffeners (polyimide or FR4) at these locations.

5. Account for ZIF Connectors

Most flex boards connect to rigid boards via ZIF (Zero Insertion Force) connectors. Design your flex tail to match the connector's pitch and thickness requirements.

When to Use Flex vs Rigid-Flex vs Rigid

Scenario	Best Choice
Simple flat board, no bending	Rigid (FR4)
Board needs to bend during assembly but stays flat	Flex
Board must flex repeatedly during use	Flex (with proper bend radius design)
3D product with multiple rigid sections	Rigid-Flex
Wearable or medical device	Rigid-Flex
LED strip	Flex

How to Order Flex PCBs

The process is the same as ordering rigid boards — export your Gerber files and send them to your manufacturer. The key difference is that flex PCBs require more detailed specifications:

Material type (polyimide, PET, etc.)
Copper weight (typically 0.5oz or 1oz)
Coverlay type and thickness
Stiffener locations and material
Bend requirements (dynamic flex vs static bend)

Pro tip: Send a mechanical drawing along with your Gerber files that shows where the board needs to bend, how far, and how often. This helps the manufacturer optimize the build-up for your specific application.

Get a Flex PCB Quote

Flex PCBs are more complex than rigid boards — that's why having an engineer review your design matters. Send us your files and we'll review the design, suggest optimizations, and give you an accurate quote.

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