Flexible PCB Manufacturer China – Custom Flex Circuits, Fast Delivery

What Is a Flexible PCB?

A flexible PCB — also called a flex circuit, flex board, FPC, or flexible circuit board —is a printed circuit board built on a thin, bendable plastic film instead of a rigid fiberglass base. Unlike a standard PCB, a flex circuit can bend, fold, and even twist without breaking.

The plastic film is almost always made of polyimide. Polyimide can handle high temperatures, it doesn’t conduct electricity, and it stays flexible through thousands of bend cycles without cracking.

Why does this matter? Because not every device has a flat, rectangular space for a circuit board. Smartphones, earbuds, smartwatches, medical implants, and camera modules all need
electronics that can curve, fold, or move with the product. A flexible PCB makes that possible — without adding heavy cables or bulky connectors.

In short: if your device bends, your circuit board should too.

Types of Flexible PCBs We Manufacture

Not all flex PCBs are the same. Here are the four main types and what each one is used for:

Single-Sided Flex PCB

A single-sided flex PCB has copper traces on just one side of the polyimide film. It’s the simplest and most affordable type to manufacture. Single-sided flex is the right choice when your circuit is relatively simple and needs to bend just once during assembly — like a flat cable connecting a camera to a phone’s main board, or a display ribbon connector.

Double-Sided Flex PCB

A double-sided flex PCB has copper on both sides of the polyimide film. The two copper layers are connected by plated through-holes called vias — the same way a standard double-sided rigid PCB works. Double-sided flex supports more complex circuits and higher component density than single-sided. It accounts for about 46% of all flex PCB production because it balances capability and cost well. Common in industrial controls, power supplies, and mid-complexity wearables.

Multi-Layer Flex PCB

A multi-layer flex PCB stacks three or more copper layers inside the polyimide structure.This allows very complex circuits, controlled impedance traces, and dedicated power/ground planes — all in a board that still bends. Multi-layer flex is common in high-frequency RF designs, medical imaging equipment, and aerospace electronics where signal integrity and weight reduction are both critical.

Rigid-Flex PCB

A rigid-flex PCB combines rigid FR4 sections and flexible polyimide sections in a single board. The rigid areas hold heavy components and connectors. The flexible section connects them — bending around tight corners or across hinges without any cables. This eliminates connectors, reduces weight, and improves reliability. Rigid-flex is common in aerospace, military, medical devices, and foldable consumer electronics. We have a dedicated page with full rigid-flex specifications:
→ Further Reading: Rigid-Flex PCB Manufacturing

Flexible PCB Manufacturing Capabilities

Here’s exactly what we can build. If your project needs something outside these specs, contact our engineering team for a custom quote.

Specification	PCBINQ Capability
PCB type	Single-sided / Double-sided / Multi-layer / Rigid-flex
Layer count	1 – 10 layers (flex); up to 20 layers (rigid-flex)
Base material	Polyimide (PI) — standard; Polyester (PET) — low-cost option
Minimum trace width / spacing	0.075 mm / 0.075 mm
Minimum via diameter	0.2 mm drilled; 0.1 mm laser (HDI flex)
Board thickness	0.05 mm – 0.5 mm
Copper weight	0.5 oz – 2 oz
Coverlay material	Polyimide coverlay; LPI solder mask
Stiffener material	FR4, polyimide, steel, aluminum
Surface finish	ENIG, HASL, OSP, Immersion Silver, Hard Gold
Max board size	450 mm × 1,000 mm
Min bend radius	6× board thickness; 10× (dynamic/repeated bending)
Dynamic flex life	Up to 1,000,000 bend cycles
Lead time	7 – 12 business days
Lead time	3 – 5 business days
Quality standard	IPC-6013 , IPC Class 2 & Class 3
Certifications	ISO 9001, UL, RoHS, REACH

What Materials Go Into a Flexible PCB?

The material choices in a flex PCB determine how it bends, how much heat it survives, and how long it lasts. Here’s what you need to know:

Polyimide (PI) — The Standard

Polyimide is the most common base material for flexible PCBs. You might recognize it as Kapton — a brand name from DuPont that became the industry shorthand for this yellow-orange film.

Polyimide handles temperatures from -269°C up to 400°C without melting or cracking. It survives soldering. It stays flexible after years of repeated bending. And it’s a natural electrical insulator, so your copper traces don’t short-circuit through the film. Almost every high-reliability flex PCB — in aerospace, medical devices, and automotive electronics — uses polyimide as its base.

Polyester — The Budget Option

Polyester film is cheaper than polyimide and works fine for simple, low-temperature applications. The trade-off: it can’t survive the temperatures of standard PCB soldering, so components must be attached with conductive adhesives instead. PET flex circuits are common in membrane keyboards, disposable medical sensors, and simple ribbon cables. If your application involves reflow soldering, use polyimide.

Coverlay — The Protective Layer

The coverlay is the outer protective film bonded over the copper traces. It works like the solder mask on a rigid PCB — protecting the copper from moisture, oxidation, and physical damage — but it’s made of flexible polyimide film rather than liquid epoxy. Openings in the coverlay expose the pads where components are soldered.

Stiffeners — Targeted Rigidity

A flex PCB can have rigid sections added exactly where they’re needed — under component areas, at connector zones, or anywhere the board needs to stay flat. These reinforcements are called stiffeners. They’re usually made of FR4, polyimide, steel, or aluminum. Stiffeners don’t affect the flexible section of the board at all — the bend area stays fully flexible.

Flexible PCB vs Rigid PCB — Which Do You Need?

Both types are printed circuit boards. The difference is what they’re made of and what they can do. Here’s a quick side-by-side:

Feature	Rigid PCB (FR4)	Flexible PCB (Polyimide)
Can it bend?	No — breaks if flexed	Yes — designed to bend and fold
Base material	FR4 fiberglass	Polyimide (PI) or polyester (PET)
Thickness	0.6 mm – 3.2 mm	0.05 mm – 0.5 mm (flex zone)
Weight	Heavier	Up to 75% lighter
Space required	More — needs flat, rectangular space	Less — wraps around curves and into gaps
Heat resistance	Up to 130°C (standard FR4)	Up to 400°C (polyimide)
Cost	Lower	Moderate to higher (offset by eliminating cables)
Dynamic bending life	Zero — not designed for movement	Up to 1,000,000 bend cycles
Best for	Stable electronics: motherboards, power supplies	Wearables, cameras, medical devices, folding devices

Flexible PCB Design Rules — What to Know Before You Lay Out Your Board

Flex PCB design has a few rules that don’t apply to rigid boards. Get these right before
you send us your files and you’ll avoid the most common prototype failure modes.

Bend Radius

The bend radius is the tightest curve your flex PCB will make. Too tight, and the copper traces crack. The rule of thumb:

• Static bending: minimum bend radius = 6× the total board thickness.
• Dynamic bending: minimum bend radius = 10× the board thickness. Go larger if you can.

Trace Routing in the Flex Zone

• Route traces perpendicular to the bend line — not parallel to it. A trace that runs along the direction of bending stretches and can crack.
• Fan traces out in the bend zone. Avoid sharp 90-degree corners anywhere in the flex area. Use curved or 45-degree routing instead.
• Keep traces centered in the flexible area. Off-center traces experience more stress during bending.

Via Placement

• Never place vias in the bend zone. Vias are rigid points. In a flex section, they concentrate stress and crack the plating.
• Teardrop your vias everywhere on a flex board — not just in high-stress areas. Teardrops distribute the bending stress across a wider area.

Stiffeners and Component Placement

• Don’t place components in the flex zone. Components are rigid. They’ll crack solder joints when the board bends.
• Add a stiffener under any area with components, connectors, or ZIF contacts. Stiffeners keep those areas rigid while the rest of the board flexes normally.

Copper Coverage

• In the flex zone, use 70% copper coverage or less. High copper density stiffens the board and reduces flex life.
• Use a hatched ground plane in the flex zone instead of a solid pour. It preserves shielding while keeping the zone flexible.

Our free DFM check catches all of these issues automatically when you upload you Gerber files. We flag problems before production starts — saving you a respin.

How Much Does a Flexible PCB Cost?

Flex PCB pricing is more variable than rigid PCB pricing. Here’s what drives your quote:

• Layer count — A single-sided flex board is the least expensive. Every additional layer adds lamination cycles, materials, and processing time. Multi-layer flex costs significantly more than single-sided.
• Board size and panel utilization — Polyimide film is more expensive per square inch than FR4. A smaller board that panels efficiently costs less per piece.
• Bend zone length — Longer flex sections require more polyimide material and more attention during manufacturing.
• Coverlay vs LPI solder mask — Polyimide coverlay is the standard for flex boards. It costs more than LPI solder mask, but it’s more flexible and more durable. For dynamic-bending applications, always choose coverlay.
• Stiffeners — Each stiffener type has different costs. FR4 stiffeners are typically the most affordable.
• Quantity — Larger orders have lower per-unit costs. Prototypes cost more per board than production runs of 500+.
• Lead time — Express 3–5 day production carries a premium over standard 7–12 day lead time.

The quickest way to get your real price: upload your Gerber files. Our instant quoting tool reads your design files and generates a real price in under 30 seconds — no email required.

Why Engineers Choose PCBINQ for Flexible PCB Manufacturing

Here’s what we do differently:

• Factory-direct pricing — No distributors, no middlemen. We make your boards in our own factory in China. That means lower prices and direct access to your production team.
• Free DFM review on every order — Our automated system checks your Gerber files for flex-specific design issues before production starts. We flag problems — and suggest fixes — before they turn into expensive reprints.
• Instant online quoting — Upload your files, get a real price in under 30 seconds. No waiting for a sales rep. No back-and-forth emails.
• No minimum order quantity — Order 5 prototype boards or 5,000 production boards. Same factory. Same quality control.
• Tested for dynamic bending — Our flex PCBs are qualified to 1,000,000 bend cycles using IPC-TM-650 test methods. If your design involves repeated bending, we can validate it meets your life-cycle spec before you commit to production.
• IPC Class 2 and Class 3 support — For medical, aerospace, and defense designs that require the highest reliability standards.
• Certified quality — ISO 9001:2015 certified. 100% electrical testing before shipment. UL listed, RoHS and REACH compliant.

Full material traceability — Every batch of polyimide and copper foil is tracked from supplier to finished board. Required for medical and aerospace applications.

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