Circuit boards are widely used in various fields

Printed circuit board { PCB circuit boards} , also known as printed circuit boards, the provider of the electrical connection in the electronic components. It has a history of more than 100 years of development; It is the design of the main landscape design; The principal advantage of the circuit board is greatly reduce wiring and fitting error, improves the automation level and rate of productive labor. According to the circuit board layer can be divided into single panel, double panel, four layer board, 6 layer board and other multilayer circuit board. Because of the printed circuit board is not generally end products, so in the name of the definition, slightly chaotic, for example: personal computer motherboards, known as the mainboard, and cannot be called a circuit board, although there is the existence of the circuit board in the motherboard, but is not the same, so the evaluation industry both on but can't say the same. Such as: because of the integrated circuit parts load on the circuit board, so the news media called him the IC board, but actually he is not the same as the printed circuit board. Usually said of the printed circuit board - refers to the bare plate Is not on the components of the circuit board. On the basic of the PCB, single panel parts on one side, the conductor is focused on the other side. Because the wires in only one side, so this kind of PCB is called single panel. Because single panel in the design of lines, there are many restrictions, Because only one side, wiring between cannot cross and must around the path alone) , so only use this kind of early circuit board. Double panel to both sides of the circuit board wiring, but it took two wires, must have the appropriate circuit connection between two sides. The 'bridge' between the circuit is called guide hole ( via） 。 Guide hole is on the PCB, or coated with metal small hole, it can be connected to both sides of the wire. Because the area of the double panel a times larger than a single panel, double panel solved because wiring of the difficulty in the single panel ( Can guide Kong Tong to the other side) , it is more suitable for use in the more complex than a single panel circuit. Printed circuit board from single to double panels, multilayer and flexible plate, and continuously to develop in the direction of high precision, high density and high reliability. The shrinking volume, reduce costs, improve performance, the printed circuit board in the process of the development of electronic products in the future, still keep strong vitality. Future printed circuit board manufacturing technology is development trend in performance to high density, high precision, fine pore diameter and thin wire, small spacing, high reliability, multiple stratification, high-speed transmission, light weight, thin direction. With the rapid development of electronic technology, circuit board processing is widely applied in various fields, almost all of the electronic devices are included in the printed circuit board. For electronic devices to work properly, reduce the electromagnetic interference between each other, to reduce the negative impact of the electromagnetic pollution to human and ecological environment, electromagnetic compatibility design cannot be ignored. This paper introduces the design methods and techniques of printed circuit boards.