Talking about PCB Design Scheme

Design PCB program should pay attention to the following five points:

1.have a reasonable direction: such as input / output, AC / DC, high frequency / low frequency, their direction should be linear (or separation), not blending each other. The aim is to prevent mutual interference. The best direction is to follow the line, but generally difficult to achieve, the most unfavorable direction is the round. For DC, small signal, low voltage PCB design requirements can be lower. So \"reasonable\" is relative.

2.choose a good grounding: under normal circumstances require a total point, this problem is quite flexible in practice. Everyone has their own set of solutions.

3.reasonable layout of the power supply filter / decoupling capacitor: generally only in the schematic diagram to draw a number of power supply filter / decoupling capacitors, but did not indicate where they should be connected. In fact, these capacitors are set for switching devices, the layout of these capacitors should be close to these components. Interestingly, when the power supply filter / decoupling capacitor layout is reasonable, the grounding point of the problem becomes less obvious.

4.lines need to be cautious: High pressure and high frequency lines should be slippery, shall not have a sharp chamfer, the corner should not be used at right angles. Ground wire should be as wide as possible, it is best to use a large area of  copper, this docking point problem has a considerable improvement.

5.although some problems occur in the post-production, but it is brought by PCB design. Such as the size of the pad or wire hole is too small, or the pad size is not properly matched to the borehole size. The distance between the solder joints is too small, wire is too fine, so we should pay attention to the PCB design.