Nearly all modern electronic products have benefitted from flexible and rigid-flex circuitry technology. Today, electronic equipment typically uses flexible circuitry for applications that must process critical signals, need to perform flawlessly in extreme environments, enable national defense, manage heat and power distribution, reduce automobile accidents and more, and do so through increasingly miniaturized design.
Advanced flexible circuit material options and customized flexible circuit design deliver unprecedented benefits to various sectors. For instance, anti-lock brake systems and engine maintenance units in vehicles are now increasingly replacing traditional wiring harness with polyimide-based circuits. Not only do these circuits save on weight and cost, they can easily withstand under-the-hood environments as well. Other examples include:
Although the concept of flexible circuitry is not new, as early researchers had patents issued in 1903, the defense and aerospace industry developments in the 1950s triggered the momentum of using flexible printed circuits as a replacement for wiring bundles. This led to a vast expansion of the use of flex PCBs across consumer and industrial electronic sectors. Beyond the 1990s, the growth of flex solutions took off with technical advancements, the demand for replacement of rigid boards, and the shrinking of wiring design footprints, including space constraints.
The markets for flexible circuits opened further with the use of all-polyimide circuitry as the base for environments where temperatures exceeded 200°C, such as under the hood of an automobile. Even space exploration is making use of flex circuits with NASA using them in Mars explorations, where flexible circuitry components facilitated capturing panoramic views of the Mars surface and the search for water there.
Manufacturers are coming up with newer fabrication techniques for flex circuits for the next generation of design options. They are using liquid crystal polymer and other similar low-moisture-absorption/high-speed dielectrics along with ultra-thin copper conductors of thicknesses less than 5 microns.
Others are experimenting with non-copper metal traces such as with cupro nickel or Inconel. These and other thermal management components on the flex circuits deliver precise heating. Such advances are improving navigation for pilots and other naval aviators, acting as deicers for aircraft wings. Flexible circuits heat up the wings quickly, shedding unwanted ice and preventing it from building up in flight, thereby improving airline safety.
Flexible circuits are also being increasingly used by hospitals for their newborn incubation chambers, surgical rooms, and equipment support, all of which require consistent and uniform temperature control. Additionally, flexible circuits are in great demand in low-power environments such as in deep-space satellites for heating, in military electronics for vision systems, and in the automotive sector for heating and cooling of seats.
The requirement for flexible circuits is evolving very fast, as they are increasingly being used in electronic devices. They are allowing equipment to become efficient, rugged, and lightweight, improving development of miniature, complex, next-generation electronics.