Flexible circuit board, for short, "soft plate", commonly known as FPC in industry, is a printed circuit board made of flexible insulating substrate (mainly polyimide or polyester film),
It has the advantages of many hard printed circuit boards. For example, it can be freely curved, winding and folding. The use of FPC can greatly reduce the volume of electronic products, and the application of electronic products to high density, miniaturized and high reliable direction. Therefore, FPC has been widely used in the fields of space, military, mobile communications, portable computers, computer peripherals, PDA, digital cameras and other fields and products.
FPC also has the advantages of good heat dissipation and weldability, easy to connect, and low comprehensive cost.
Flexible printed circuit boards are divided into single, double-sided and multi-layer plates. The base material used is polyimide copper clad plate. The material has high heat resistance, good dimensional stability, and the cover film, which has both mechanical protection and good electrical insulation properties, is made up of the final product by pressing. The surface and inner conductor of the double-sided and multilayer printed circuit board and the inner conductor are electralized to realize the electrical connection of the inner and outer circuits.
柔性线路板的功能可区分为四种，分别为引线路 、印刷电路 、连接器 以及多功能整合系统 ，用途涵盖了电脑、电脑周边辅助系统、消费性民生电器及汽车等范围
The functions of flexible circuit boards can be divided into four categories, they are lead circuits, printed circuits, connectors and multi-functional integration systems. They include computers, computers, auxiliary systems, consumer appliances and automobiles.
Type of flexible PCB
1, single panel
A single layer of PI copper sheet material is used to cover a layer of protective film after the circuit is completed, and a soft circuit board with a single layer of conductor is formed.
2, common double-sided plate
After the double sided PI coated copper plate is used to complete the double-sided circuit, a layer of protective film is added to both sides to become a circuit board with double layer conductors.
3. The substrate is made of a single panel
In the process of circuit manufacturing, a protective film is added on both sides of the circuit with pure copper foil material. It becomes a single circuit conductor with only one conductor, but on both sides of the circuit board.
4. The substrate is made of two sides
The two layer single side PI copper clad material is supplemented by bonding glue with window opening at specific position. It becomes a double-sided conductor circuit board with partial separation in the local area and two layers in the local area. The circuit board with high flexural property in the layered area is achieved.
Advantages and disadvantages of flexible PCB
(1) it can be freely bent, folded and folded, and can be arranged according to the layout requirements of the space, and it can move and expand freely in 3D space, so as to achieve the integration of component assembly and wire connection.
(2) the use of FPC can greatly reduce the volume and weight of electronic products.
(3) FPC also has the advantages of good heat dissipation and solderability, easy connection and low comprehensive cost. The design of soft and hard combination has made up for a slight lack of load bearing capacity of flexible substrates.
(1) high one-time initial cost
The soft PCB is designed for special application, manufacturing, so the circuit design, start wiring and photographic plate by the cost of higher. Unless there is a special need to apply soft PCB, it is best not to use a small amount of application.
(2) it is difficult to change and repair soft PCB
Soft PCB once made you want to change, must start from the map or the preparation of light painting program, so it is not easy to change. It is a difficult job to cover a layer of protective film on its surface, to remove it before repair, and to restore it after repair.
(3) size is limited
Soft PCB is usually made by batch process under the condition that it is not popular, so it is limited by the size of production equipment and can not be done very long and wide.
(4) improper operation and easy damage
Connected due to improper operation caused by damage to the flexible circuit, the soldering and rework operation requires trained personnel.