Flexible PCB is a circuit board that can be bent as desired according to the surface or area to be mounted. Flexible PCBs can be bent easily without damaging the circuit. Flexible PCBs are found in many devices that we use in our daily life, such as smartphones, tablets, cameras, laptops, printers.
It is the substrate material used inside the PCB that provides the flexibility of the PCB. Polyamide, also called nylon, an organic thermoplastic polymer PEEK (Polyether ether ketone), or transparent polyester film is used to make flexible PCBs.
The layers of flexible PCB are very similar to rigid PCB. A single layer flexible PCB, consists of dielectric substrate film, copper conductors, protective coating. Polyimide film, also known as kapton film, is used instead of solder mask as surface coating on flexible PCB. This high temperature resistant layer protects the circuit from damage.
Flexible PCBs are more costly to manufacture than rigid PCBs. As a result, the selling price is higher. Flexible PCBs have a number of advantages for certain applications and therefore the high cost incurred in some cases is acceptable.
For example, flexible PCBs are widely used to make electrical and mechanical connections of LEDs in automobile headlights and taillights where space for mounting is small. Similarly, LED strip, which is a decorative lighting product, is made with flexible PCBs. In this way, LED light strips can be easily applied to different geometric shapes.
FlexibFlexible PCBs eliminate the need for connectors and cables in many applications, improve connection reliability, reduce assembly time, reduce device dimensions and thus reduce overall cost.
Other advantages of flexible PCB are that it is lighter than rigid circuit boards and has high resistance to vibration. For this reason, flexible circuit boards are often preferred in mobile electronic devices.
Flexible PCBs are slightly more difficult to repair than rigid PCBs. Repairing a damaged flex PCB requires appropriate equipment and a great deal of experience. To interfere with the PCB, the protective film surrounding the circuit must first be removed. Protection should be restored once the repair process is complete.
The advantages and disadvantages of using flexible PCB should be carefully considered during the design phase. Flexible PCB selection is mandatory in some applications. For applications other than this, it can be decided which PCB to be used by evaluating the cost and benefit.
