Brief Classification Of Flexible Printed Circuits (FPC)
In this section, we would like to give brief classification of FPC. First of all, let’s start with FPC’s definition! Simply defined, flexible circuitry is an array of conductors bonded to a thin dielectric film. It has the unique property of being a three-dimensional circuit that can be shaped in multi planar configurations, rigidized in specific areas, and molded to backer boards for specific applications. It offers the advantages of increased reliability, greater impedance control, weight and space savings, and a reduction in mechanical connectors.
Flexible printed circuits are made with a variety of materials and techniques suitable for different applications and can be single- and multilayer or rigid-flex. Considerations such as cost solder ability, and dynamic (continual) flexing will determine which materials are used to fabricate a flexible circuit. Circuit density can be increased by adding layers to the circuit and decreasing line widths and spacing.
Primarily there are four types of flexible circuitry: single-sided, double-sided, multilayer, and rigid-flex. Single-sided circuits consist of a single conductive layer and are the simplest type of flexible circuits. They are also the most broadly specified, least expensive, and produced in the greatest volume. Single-sided circuits are always specified for dynamic flexing applications such as printer and disk drive heads. Double-sided and multilayer circuits cannot be used in dynamic flexing applications as the copper will fatigue in a short time.
The mainly base material is polyimide CCL with high heat resistance and good stability. It is pressed with the cover lay that is featured for mechanical protection and good electrical insulation properties. The outer and inner conductor of double sided flexible PCB or multilayer flexible PCB achieve the electrical connection of the wiring in different layers by metallization.
According to the combination method of the substrate and the copper foil, flexible PCB can be divided into plastic flexible PCB and non-plastic flexible PCB. The copper foil and the substrate of plastic flexible PCB is connected together by glue which is widely used. The copper foil and the substrate of non-plastic flexible PCB is connected together by pressing machine. The latter is better in flexibility, combination of copper foil and substrate, flatness of pad and so on. As the cost is relatively higher, it’s generally used in the device with high demand, such as COF.
The same with the other industrial technology, flexible PCB has widely development and prosperity should experience a long period of transformation and innovation. However, some aspects of FPC manufacturing still need further improvement, such as high initial cost, the difficulty of modifying and mending, the restriction of the dimension and easy damage for improper operation. In order to meet FPC’s market, Wonderful PCB will make great effort to offer high quality flexible PCB in the future.
About the Author
Wonderful PCB Limited is experienced PCB board manufacturer.We specialize in manufacturing and selling high-precision, high-density double-sided PCBs and multilayer PCBs. Wonderful PCB Technology Co., Ltd. is a professional manufacturer and exporter for PCB and FPC prototype, PCB assembling, and stencil. We have capability in making PCB layer from 1layer to 28layer. Especially with advantages in 2-8layers! Approved with ISO, UL, TS16949 certifications, our PCB is widely exported to Asian, Western Europe, America and so on! More details about our company please kindly visit our website .
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