In any power design, the physical design of the PCB board is the last step.The design method determines the electromagnetic interference and power supply stability. Let's make a specific analysis of these segments:

1.From the schematic diagram to the PCB design process, and establish the component parameters. > input principle mesh Table > Design Parameter Settings > manual layout >> manual wiring - > Validation Design - > check ->CAM output.
2.Parameter setting the distance between adjacent wires must meet the electrical safety requirements, And in order to facilitate operation and production, the spacing should be as wide as possible.The minimum distance should be at least suitable for the withstand voltage.When the wiring density is low, the spacing between signal lines can be increased appropriately.The signal lines with high and low levels should be as short as possible and increase the distance.In general, the distance between the lines is set to 8mil..
The distance from the inside edge of the welding plate to the edge of the printed circuit board must greater than 1mm, that can avoid the defect of the plate during processing.When the connection between the pad and the wire is thinner, the connection between the pad and the wire must be designed to be water droplets. The advantage is that the pad is not easy to peel, and the wire and pad are not easily broken.

3.The practice of component layout has proved that even if the circuit schematic design is correct and the printed circuit board design is improper, it will adversely affect the reliability of electronic equipment. For example,If the two fine parallel lines of the printed board are very close,that will delay the signal waveform and form a reflection noise at the terminal of the transmission line.Because of the disturbance caused by the poor consideration of the power supply and ground wire, the performance of the product will be reduced.So, when designing printed circuit boards,we should adopted to the correct method.

4.The wiring switch power contains a high frequency signal.Any printed wire can play an antenna role on PCB.The length and width of the printed circuit will affect its impedance and inductance, thus affecting the frequency response.Even if  a printed line through a DC signal will be coupled to the RF signal from the adjacent printed circuit and cause circuit problems (even radiating the interference signal again).

5.After checking the design of the wiring,It is necessary to carefully check whether the wiring design is in line with the rules set by the designer.At the same time, it is necessary to confirm whether the rules are in line with the requirements of PCB production process.The distance between the line and line, line and element welding disk, line and through hole, element welding disk and through hole, through hole and through hole is reasonable, and whether it meets the production requirements.Is the width of the power cord and ground wire suitable? Is there any place where the ground wire can be widened in PCB? Note: there are some mistakes that can be ignored. For example,Some of the Outline of the connector is placed outside the frame, There will be a mistake when you check the distance. In addition, each time the line is modified and the hole is passed, the copper will be re coated once.

6. review the "PCB Checklist",The contents include design rules, layer definition,  line width, spacing, pads,and over hole settings.It is also important to review the reasonableness of the device layout. check the wire of the power supply and the ground line network,The line of the ground line network, The walking line and shielding of the high speed clock network and the arrangement and connection of decoupling capacitors.