The design rules of PCB layout

In the high-speed PCB design process, special components refer to the key components of the high-frequency part, the core components in the circuit, the components that are susceptible to interference, the high-voltage components, the components with large heat, and some components. For heterosexual components, you need to carefully analyze the location of these special components to make the layout meet the circuit function and pcb fabrication requirements. Incorrect placement of them will cause circuit compatibility issues, signal integrity issues, and lead to PCB design failures.

When considering placing special components in a PCB design, first consider the PCB size. When the PCB size is too large, the printed line is long, the impedance increases, the resistance to drying decreases, and the cost also increases; when it is too small, the heat dissipation is not good, and the adjacent lines are easily interfered. After determining the PCB size in the PCB design process, determine the location of special components. Finally, according to the functional unit, all components are laid out. When arranging, the location of special components usually follows the following principles:

1. PCB design shortens the connection between high-frequency components as much as possible, and minimizes their distribution parameters and mutual electromagnetic interference. The susceptible components should not be too close, and the input and output should be as far as possible.

2. Some components or wires may have a higher potential difference, and their distance should be increased to avoid accidental short circuit caused by discharge. High-voltage components should be placed out of reach of hands.

3. Parts weighing more than 15G can be fixed with brackets and then welded. Those heavy and hot components should not be placed on the circuit board, should be placed on the bottom plate of the main frame, and heat dissipation should be considered. The heating element should be far away from the heating element.

4. For the layout of adjustable components, such as potentiometers, adjustable inductors, variable capacitors, micro switches, etc., the structural requirements of the entire wrench should be considered. When the structure permits, some commonly used switches should be used. Keep it in an easily accessible place. The layout of the components is balanced, the density is dense.