The PCB board is composed of various circuit diagrams and components, so we must fully consider the layout of the circuit and the placement of components when designing, because this will not only affect the appearance of the PCB, but also affect the quality of the product. Performance, we must pay attention to the following issues when designing PCB boards.

1. Component layout
Component placement affects not only the aesthetics of the PCB, but also the performance of the circuit. The following points should be paid attention to in component layout:
1) Lay out key components (such as single-chip microcomputer, DSP, memory, etc.) first, and then lay out other components according to the direction of address lines and data lines.
2) The wires drawn from the pins of high-frequency components should be as short as possible to reduce the impact on other components and their circuits.
3) Analog circuit modules and digital circuit modules should be arranged separately and not mixed together.
4) The components with strong current should be as far away from other components as possible, and placed in places that are not easy to touch during debugging.
5) For heavy components, a bracket should be installed on the PCB to prevent the components from falling off.
6) For some serious heating components, a heat sink must be installed.
7) Components such as potentiometers and variable capacitors should be arranged in places that are convenient for debugging.

2.PCB wiring
The following basic principles should be followed when wiring.
1) The wires at the input end and the wires at the output end should avoid parallel wiring as much as possible to avoid coupling.
2) When the wiring is allowed, the width of the wire should be as large as possible, generally not less than 10mil.
3) The minimum spacing of the wires is determined by the insulation resistance between the wires and the breakdown voltage. It should be as large as possible within the allowable wiring range, generally not less than 12mil.
4) The data lines and address lines of the microprocessor chip should be wired as parallel as possible.
5) Turn as little as possible when wiring. If you need to turn, generally take a 45-degree direction or an arc shape. In high-frequency circuits, right angles or acute angles cannot be taken when turning to prevent signal reflection of high-frequency signals when the wire turns.
6) The width of the power line and the ground line should be greater than the width of the signal line.

3. When designing the wiring diagram, pay attention to the order of the pins and the spacing of the components should be reasonable.

4. Under the premise of ensuring the performance requirements of the circuit, the design should be reasonable, the external wiring should be used less, and the wires should be routed according to the requirements.

5. When designing the wiring diagram, minimize the wiring and try to make the lines concise and clear.

6. The width of the terminal strip and the spacing of the lines should be moderate. The spacing between the two pads of the capacitor should be as close as possible to the spacing of the capacitor leads.

7. The design should be carried out in a certain order, for example, from left to right, from top to bottom.