Flexible circuits are designed to improve space utilization and product design flexibility, allowing for smaller and higher density installations, as well as helping to reduce assembly processes and enhance reliability. It is the only solution to meet the requirements of miniaturization and mobility of electronic products.
Flexible circuits are copper circuits etched onto a polymer substrate, or polymer thick film circuits printed. For devices that are both thin and light, compact and complex, the design solutions range from single-sided conducting circuits to complex multi-layer THREE-DIMENSIONAL packages. The total mass and volume of the flexible package is 70% less than that of the traditional element wire harness method. Flexible circuits can also gain additional mechanical stability by increasing their strength by using reinforced materials or liners.
Flexible circuits can move, bend and twist without damaging wires and can come in different shapes and special package sizes. The only limitation is the problem of volume space. Being able to withstand millions of dynamic bends, flexible circuits can be well suited to internal connected systems that move continuously or regularly as part of the functionality of the final product. Some products that require electrical signal/power movement and small form factor/package size benefit from flexible circuits.
Flexible circuits provide excellent electrical performance. Low dielectric constant allows fast transmission of electrical signals; Good thermal performance makes components easy to cool down; The higher glass conversion temperature or melting point allows the components to operate well at higher temperatures.
By reducing the amount of hardware required for interconnections, such as solder joints, trunks, baseboard lines and cables commonly used in traditional electronic packages, flexible circuits can provide higher assembly reliability and yield. Because the traditional interconnect hardware composed of complex multiple systems is prone to high component dislocation rate during assembly. With the advent of quality engineering, a thin, flexible system was designed to be assembled in only one way, eliminating the human error usually associated with independent wiring engineering.
Early flexible circuits are mainly used in small or thin electronic products and rigid printed boards and other fields. In the late 1970s, it was gradually applied to computers, digital cameras, inkjet printers, car stereos, OPTICAL disk drives (see Figure 11-1) and hard disk drives and other electronic products. Open a 35mm camera with 9 to 14 different flexible circuits. The only way to reduce volume is for components to be smaller, lines to be more precise, joints to be closer together, and things to be bendable. Pacemakers, medical devices, video cameras, hearing AIDS, laptops -- almost everything in use today has flexible circuits inside it.
