The circuit board can be called a printed circuit board or a printed circuit board. The English name is (PrintedCircuitBoard)PCB, (FlexiblePrintedCircuitboard) FPC circuit board (FPC circuit board is also called flexible circuit board). A substrate made of a highly reliable and flexible printed circuit board. It has the characteristics of high wiring density, light weight, thin thickness, and good bendability), soft and hard combination board (reechas, Softandhardcombina TIonplate) )-The birth and development of FPC and PCB gave birth to a new product of soft and hard board.

　　 Therefore, the rigid-flex board is the flexible circuit board and the rigid circuit board. After pressing and other processes, they are combined according to the relevant process requirements to form a circuit board with FPC characteristics and PCB characteristics.

　　Why the circuit board is green

　　 The green part is called solder mask, and the ingredients are resin and pigment, and the green part is green pigment. There are also various other colors, which are no different from decoration paint. The assembly solder is paste-like and flowable before it is printed on the circuit board. After it is printed on the circuit board, it is finally "cured" to allow the resin to be cured and hardened by heat. The purpose of solder mask is to protect the circuit board from moisture, oxidation and dust. The place that is not covered by the solder mask is usually referred to as the pad, which is used for soldering solder paste.

　　 Generally, we choose green, because green is less irritating to the eyes, and the production and maintenance personnel will not be prone to eye fatigue when they are staring at the PCB board for a long time. Commonly used colors are yellow, black, and red. All colors are painted on the surface after it is manufactured.

　　 There is another reason, because the commonly used color is green, so the factory spares a lot of green paint, so the cost of oil is relatively low. And because when repairing the PCB board, different wiring is easier to distinguish the difference from white, while black and white are relatively difficult to see. In order to distinguish its own product grade, each factory uses two colors to distinguish high-end series and low-end series.