Electronic Design - Layout principles and SMT patch technology in high-speed PCB design

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 high heat, and some components. For components of the opposite sex, it is necessary to carefully analyze the location of these special components to make the layout meet the requirements of circuit functions and production requirements. Their incorrect placement can cause circuit compatibility issues, signal integrity issues, and lead to PCB design failures.

When considering placing special components in a PCB design, the PCB size must first be considered. When the PCB size is too large, the printed line will be long, the impedance will increase, the anti-drying ability will be reduced, and the cost will also increase; when it is too small, the heat dissipation will not be good, and adjacent lines will be easily interfered. After determining the size of the PCB in the PCB design process, determine the location of the special components. Finally, according to the functional units, all the components are laid out. When laying out, the location of special components usually follows the following principles:
1. The PCB design minimizes the connection between high-frequency components and minimizes its distribution parameters and mutual electromagnetic interference. Components that are susceptible to interference should not be too close, and the input and output should be as far away as possible.
2 Some components or wires may have a higher potential difference, and their distance should be increased to avoid accidental short circuits caused by discharge. High-voltage components should be placed where they cannot be reached by hand.
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, but should be placed on the bottom plate of the main frame, and heat dissipation should be considered. The thermal element should be kept away from the thermal 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 allows, 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, and it is not top-heavy.
The success of products lies in focusing on internal quality. The second is to consider the overall aesthetics, both of which are more perfect boards and become a successful product. The quality is mainly attributed to the materials and manufacturing processes of the circuit board production, and the overall aesthetics must depend on the aesthetics of the schematic design of the PCB design engineer.
SMT technology introduction
Surfadcd Mounting Technolegy (SMT) is a new generation of electronic assembly technology that will use traditional electronic components.
The device is compressed into only a few dozen devices, so as to achieve high density, high reliability, miniaturization and low cost of electronic product assembly.
And automated production. This miniaturized component is called: SMY device (or SMC, chip device). Assemble components for printing
The process on (or other substrate) is called the SMT process. The related assembly equipment is called SMT equipment.
At present, advanced electronic products, especially computers and communication electronic products, generally use SMT technology. International SMD
The output of parts is increasing year by year, while the output of traditional devices is decreasing year by year, so as time goes by, SMT technology will become more and more popular.