In addition to fixing all kinds of small parts, the main function of PCB is to provide electrical connections to each of the above parts. As the electronic equipment becomes more and more complex, more and more parts are needed, and the wiring and parts of PCB are becoming more and more intensive.
The standard PCB looks like this -- the motherboard. The bare Board, which has no spare parts, is also often referred to as the Printed Wiring Board (PWB).
The substrate of the board itself is made of insulating and not easily bent material. On the surface can see tiny Line material is copper foil, originally copper foil is covered in across the board, and to get rid of the central in the manufacturing process of etching, stay part to turn into a network of fine lines. These lines are called conductor patterns or cabling, and are used to provide circuit connections to parts on the PCB.
As the current technology of the electronics industry is more and more complicated, the number of layers of PCB board is higher and higher. In the area of board card is more common is 4 layer board and 6 laminated board two kinds. Sandwich plate has a big advantage is that the power and ground network can take more current block out more interference at the same time, thus can greatly improve the stability of the whole system.