Timer pcb circuit board
1. Circuit board principle - introduction
Printed Circuit Board (PCB for short), also known as Circuit Board, PCB Board, aluminum substrate, high-frequency Board, ultra-thin Circuit Board, ultra-thin Circuit Board, Printed Circuit Board (copper etching technology), is an important electronic component, is the supporting body of electronic components, is the provider of electronic components Circuit connection.The traditional circuit board, USES the printing etch resist the method, makes the circuit circuit and the chart surface, therefore is called the printed circuit board or the printed circuit board.As electronic products are constantly miniaturized and refined, most of the current circuit boards are made by attaching the etching resist (pressure film or coating), which is developed by exposure and then etched to make the circuit boards.
|2. Circuit board principle - structure|
The circuit board is mainly composed of pad, through hole, mounting hole, wire, component, connector, filling, electrical boundary, etc.Common board layers include Single Layer PCB, Double Layer PCB and Multi Layer PCB.The main functions of each component are as follows:
Pad: a metal hole used to weld the pins of components.
Through hole: there are metal through hole and non-metal through hole, among which the metal through hole is used to connect the component pin between each layer.
|Mounting hole: used to fix circuit board.|
Wire: copper film of electrical network used to connect the pins of components.
Connectors: components used to connect circuit boards.
Filling: copper applied to ground networks to effectively reduce impedance.
Electrical boundary: used to determine the size of the circuit board, all components on the circuit board must not exceed this boundary
3. Principle of circuit board
Working principle of the circuit board: it USES the insulating material on the board to separate the copper foil conductive layer on the surface, making the current flow in various components along the predesigned route to complete functions such as doing work, amplification, attenuation, modulation, demodulation and coding.
On the most basic PCB, parts are concentrated on one side and wires are concentrated on the other.Because the wire only appears on one side, the PCB is called a single panel.A multi-layer board with multiple wires, which must be properly connected between the two layers. This bridge is called a via.The basic design process of circuit board can be divided into the following four steps:
(1) design of circuit schematic diagram the design of circuit schematic diagram mainly USES the schematic editor of Protel DXP to draw schematic diagram.
(2) generate reports - network statement that shows the links of all components in the circuit principle and relationship of the report, it is connected to circuit schematic design and circuit board design of bridge and link, through the network statements circuit schematic diagram, can quickly find the components, the relation between which provide convenience for the back of the PCB design.
(3) the design of printed circuit board -- the design of printed circuit board is the PCB design, which is the final form of the transformation of circuit schematic diagram. The design related to this part is more difficult than the design of circuit schematic diagram. We can complete the design of this part with the help of the powerful design function of Protel DXP.
(4) generate printed circuit board reports -- after the design of printed circuit board is completed, various reports shall be generated, such as the report of pins, the report of circuit board information, the report of network status, etc., and the printed circuit diagram shall be printed at last.