FPC is an abbreviation from flexible circuit board, the update products after universal application of rigid PCB. In dictionary, FPC is a technology for assembling electronic circuits by mounting electronic devices on flexible plastic substrates, such as polyimide, PEEK or transparent conductive polyester film.
Flexible
printed circuit boards (FPCs) are applied to various electronic devices due to their mechanical characteristics and are indispensable to electronic devices requiring system miniaturization, weight reduction and multi-functionality. Examples of applications for FPCs include cell-phone liquid crystal display enclosure, hinge parts, keypad, battery enclosure and interface components. FPCs are also used in optical pickup and device interfaces inside hard disk drives, digital still cameras and digital camcorders. By now, we could see that compared with rigid PCB, FPC is newly innovated connection mode between electronic components. Flexible PCB market now is poised for more growth. 2012 was a bumper year for flexible printed circuit board manufacturers, a new report says. The global flex circuit market reached $10.68 billion, up 15.2% from 2011, says Research and Markets. Moreover, FPC will maintain the strong growth momentum in 2013, Research and Markets said. The global market is expected to grow another 8.9% year-over-year to $11.63 billion this year.
But why make FPC market growing and keep prosperous in the following years? As we all know, the electronic market is pursuing portable and high density products. The traditional rigid PCB cost too much space in a circuit board and has limited space for mounting components, which cannot meet the requirement of modern development tendency. So FPC takes an advantage of opportunity to grow. Of course, there’re several reasons that the continuous boom of FPC.
Weight& Space-saving:
Flexible PCBs are with thinner board thickness. Today, the most common flexible printed circuit substrates are 12.5 - 25 µm thick, with the trend toward even thinner materials. Two primary types of copper foil are used for flex: electrolytic copper foil and rolled copper foil. Electrolytic copper foils typically come in thicknesses of 18 or 12 µm; while most rolled copper foils are 18 µm thick, which could be light weight. It can be bent, rolled, folded freely, can be arranged randomly according to the space, can be moved and stretched in 3-D space, then integrate the components assembly and wiring connection.
Better Electrical Performance:
The flexible circuit provides good electrical performance. Lower dielectric constant allows electrical signals to transmit quickly. Good thermal performance makes the assembly easy to cool. Higher glass transfer temperature or melting point makes the assembly work well at higher temperature.
Thermal and Mechanical Characteristics
Flexible circuits commonly pass through different electrical, thermal, and mechanical environments. For example, the basic disk drive circuit moves back and forth millions of time over a rotating platter. Electrically, the flexible printed circuit compromises its signal integrity each time a trace carrying a signal is moved with respect to the surrounding electrical environment. Thermally, the circuit is exposed to the heat generated within the disk drive enclosure. Mechanically, the circuit works like a spring, either resisting or adding force to the mechanical movement.
Conclusion
Flexible circuitry is a medium that offers many advantages over traditional interconnection methods and, in many cases, is the only viable solution. When deciding whether to use flexible or traditional wiring interconnects, several factors need to be considered. If the application requires high packaging density, dynamic flexing, bonding sites for digital devices, and high reliability over time, then flexible circuitry is probably the best choice.
