Flexible PCB

About flexible PCBs and their advantages

What is a flexible PCB?

A flexible PCB (flexible printed circuit board, flex PCB, or just FPCB) is a printed circuit technology using a flexible substrate instead of a rigid one (generally FR4). The flexible substrate can have different thicknesses and the most common materials used are polyimide (also known by the name Kapton®), PET, and PEN.

Other materials can also be used, including woven fibres such as fibreglass or LCP for RF applications.

Quelques produits de circuits imprimés made in français
Gros plan sur la fabrication d'un circuit imprimé

What are the main advantages of a flex PCB?

The main advantages of FPCBs are their reduced weight and size compared to rigid PCBs while still allowing for the assembly of ordinary components. Because they can be easily reshaped in three dimensions and offer great reliability of contact, flexible PCBs can also be used to replace wired connections. As such, a single flex PCB can replace several rigid PCBs or even a series of cables.

Why should I use an FPCB in my products?

Flexible PCBs help you get around the constraints of rigid FR4 PCBs. Thanks to their characteristics, FPCBs can be easily incorporated into complex environments:

  • Flexible – it’s easy to shape and adapt flex PCBs to the geometry of your product in all three dimensions;
  • Compact – FPCBs reduce the size of your product;
  • Light – they’re easy to set in place and they reduce weight;
  • Reliable and strong – flexible PCBs can improve contact at connections and offer excellent mechanical characteristics in dynamic situations;
  • High-performance – they have advantageous dielectric properties (particularly impedance).
Réalisation d'un circuit imprimé, en action, made in Alsace

Does a flexible PCB work well under extreme conditions of usage (temperature, humidity, vibration, etc.)?

Flex PCBs work well for both static and dynamic applications in sectors such as electronics and lighting manufacturing, medical, aeronautics, defence, space, and more. FPCBs perform under the most extreme usage conditions, presenting better mechanical strength and dielectric characteristics than rigid PCBs, particularly when it comes to resistance to vibrations and high temperatures.