• +61 1300 BUY PCB (1300 289 722)
  • +61 3 9111 1887
We make a difference (An ISO 9001 & ISO 13485 certified company)

For quick, professional and Friendly PCB manufacturing and PCB assembly you can rely on, talk to QualiEco Circuits

Technical Articles

Technical Articles

Flexible PCBs (Part I) - Pure Flexible and Hybrid Rigid-Flexible PCBs, A New Era in Electronics Manufacturing

The technology, which was out of reach all these years due to its cost and complexity, is now affordable, convenient and less complicated – thanks to the rise in demand in wearable electronics. The cost is still a little more expensive than rigid PCBs but the time is not far from when the manufacturing cost of flexible PCBs would be at par with rigid PCBs.

Why flexible PCBs are getting popular?

The technology offers reduced volume and weight, increased electrical performance, larger design freedom and improved interconnect reliability. Increased use in handheld and mobile devices demand reduction in form factor, increased functional density and enlarged user comfort, which can only be achieved with flexible printed circuit board technology. A flexible circuit board is generally installed bent, folded or twisted. Flexible PCBs have not only replaced wiring and connectors but have also allowed designers to create configurations and complex geometries that were impractical with rigid printed circuit boards.

Basics of Flexible Circuits

Two major varieties of flexible circuits can be manufactured
(1) Pure Flexible PCB
(2) Rigid-flexible PCB

Pure Flexible PCB
Flexible Printed Circuits Boards made their introduction into the electronics industry as substitutes for cable assemblies. It is a patterned arrangement of printed circuitry and components that utilizes flexible based material with or without flexible coverlay. A flexible PCB is nothing but a pattern of conductive traces bonded on a flexible substrate like polyimide (PI) – similar to FR-4 and CEM in rigid PCBs.

Rigid-Flexible PCB
Rigid-Flexible circuit boards are made of rigid circuits (FR-4 PCB) and Flex circuits and circuitries. The rigid circuits (FR-4 PCB) are connected with single or multiple flex through PTH (via), inside or outside of the Flex circuit layer, so it enjoys the advantage of both Rigid FR-4 PCB and Flex circuit.

Advantages of Flexible Circuits

The primary benefits of flexible PCB compared to traditional cabling and rigid boards include the following benefits:

  • Reduced wiring errors
  • Elimination of mechanical connectors
  • Unparalleled design flexibility
  • Higher circuit density
  • More robust operating temperature range
  • Stronger signal quality
  • High vibration resistance
  • Improved reliability and impedance control
  • Size and weight reduction

Disadvantages of Flexible PCBs

  • Higher material cost than rigid or rigid flex PCB
  • Low temperature ability in flex circuits
  • More difficult and complex assembly for contract manufacturer or independent assembler (please choose your PCB assembler/contract manufacturer carefully for your FPCB assembly requirements)
  • Easily damaged through improper handling (easy to bend and dent)
  • Sensitive to scratching
  • Difficult or impossible to repair once damaged

Things to know and understand while ordering Flexible PCBs

PCB Thickness
In general, following are the final PCB thicknesses you should expect from QualiEco Circuits:

No. of Layers Final PCB thickness
1 >= 0.12mm and <= 0.2mm
2 >= 0.17mm and <= 0.3mm
4 & above >= 0.25mm

* Above figures are for general purposes only

Bend Radius
Depending on the number of layers, following are the bend radius you should expect. Please confirm with our technical team, if you have any doubt.

No. of Layers Bend Radius
1 6-8 times PCB thickness
2 10-15 times PCB thickness
4 & above >=12 times PCB thickness

* Above figures are for general purposes only

Stiffeners are a less expensive alternative to rigid-flex PCBs. Some components (e.g. ZIF connectors) require rigidity in the PCB for better mounting. Stiffeners are materials added to a flexible circuit to fulfil this purpose.

3 types of material normally used as stiffener – Polyimide, Rigid FR-4 and Metal (e.g. stainless steel or aluminium)

QualiEco’s FPCB manufacturing capabilities

We can manufacture almost any type of flexible and rigid-flexible PCBs. Following are some of our capabilities:

  • Single, double and multi-layer (up to 12 layers) flexible/rigid-flexible PCBs
  • Base material stock in the range of 1-5mil (i.e. 0.025-0.127mm)
  • Minimum 2mil (i.e. 0.05mm) track width and spacing
  • Minimum 0.1mm finish hole size
  • Polyimide, Rigid FR-4 and Metal – all 3 types of stiffeners
  • Apart from yellow coverlay, other colours like blue, red, white and black are also possible (we already trialled different colours successfully)

PCB Design Tips

When designing a PCB, try to limit the amount of draws you use. Draws use a lot of memory and slow the programming time. Use a flash for pads instead.

More tips...
Contract Assembly

Contract Assembly

We are one-stop solution provider for all your contract assembly requirements. We have the capability and resources to provide PCB assemblies, as well as cable and harness assemblies.

Learn more

SMT stencils

SMT stencils

More efficient manufacturing of solder paste SMT stencils.

Learn more

PCB design

PCB design

We'll review your PCB designs and identify refinements for easier manufacturing.

Learn more

What our customers say?

For printed circuit boards (PCBs) or PCB assembly you can count on. Talk to the friendly and experienced team at QualiEco Circuits, Australia.