In PCB (Printed Circuit Board Assembly) assembly, anti-interference design is the key to ensure the stability and reliability of electronic products. Electromagnetic interference (EMI) and radio frequency interference (RFI) may lead to abnormal board function or failure, so it is very important to take effective anti-interference design measures in the PCB assembly process. In this paper, we will discuss how to achieve anti-interference design in PCB assembly, including reasonable layout design, selection of appropriate materials, the use of shielding technology and optimisation of power supply design and other aspects.
Reasonable Layout Design
1、Component layout Optimisation
Component layout optimisation is the basis of anti-jamming design. By reasonably arranging the components on the circuit board, you can reduce the interference between the source of interference and sensitive areas.
Separation of sensitive circuits: Separate high-frequency signal lines and low-frequency signal lines are arranged to reduce interference between signals.
Reasonable wiring: Avoid long cables and cross wiring to shorten the signal path and reduce the possibility of signal attenuation and interference.
Increase ground: Arrange enough ground lines on the board to provide a stable ground reference and reduce the impact of interference on the circuit.
Implementation strategy: Conduct a detailed circuit layout analysis during the design phase to ensure that components and wiring are reasonable and reduce the risk of interference.
Selection of Suitable Materials
1、Use anti-interference materials
Selection of appropriate materials is essential to improve the anti-interference ability of the circuit board. Anti-interference materials can effectively reduce electromagnetic interference and radio frequency interference.
High-frequency PCB substrate: Select PCB substrates with good high-frequency performance, such as PTFE or ceramic substrates, to reduce signal loss and interference.
Anti-interference coating: Use anti-interference coating or shielding materials to cover sensitive areas of the circuit board to prevent external interference.
Implementation strategy: According to the operating frequency and environmental requirements of the circuit board, select the appropriate materials and coatings to enhance the anti-interference performance of the circuit board.
Use of Shielding Technology
1、Electromagnetic Shielding
Electromagnetic shielding technology reduces the impact of interference on the circuit by physically isolating the interference source and sensitive areas.
Metal Shield: Use a metal shield to cover critical areas of the circuit board to prevent electromagnetic waves from entering or leaving these areas.
Shielding Frames: Shielding frames are placed on the outside of the circuit board to protect it from external interference.
Implementation strategy: Consider the application of electromagnetic shielding technology in the design, select the appropriate shielding materials and structures to ensure that the circuit board’s anti-interference capability.
2、Grounding Technology
Good grounding techniques can effectively reduce interference and noise, provide a stable ground reference.
Ground plane: use the ground plane as the circuit board ground reference, reduce ground impedance and interference.
Grounding holes: Arrange enough grounding holes on the circuit board to ensure good current conduction and stability.
Implementation strategy: Optimise the grounding design to ensure a stable ground reference for the board and improve anti-interference performance.
Optimise Power Supply Design
1、Power Filtering
Power supply filtering can effectively reduce power supply noise and interference, improve the stability of the circuit board.
Filter: Add filters on the power line, such as LC filters or RC filters, to filter out high-frequency noise and interference.
Decoupling capacitors: Add decoupling capacitors near the power supply pins to reduce the impact of power supply noise on the circuit.
Implementation strategy: select the appropriate filters and decoupling capacitors, according to the power supply noise characteristics of the optimised design, to enhance the stability of the power supply and anti-interference capability.
2、Power Supply Layout
Power supply layout optimisation helps to reduce power interference and noise.
Power line layout: Separate the power line from the signal line to reduce the interference of power noise on the signal.
Power supply layer design: Use a dedicated power supply layer in a multi-layer PCB to provide a stable power supply and reduce noise.
Implementation strategy: Optimise the power line and power supply layer design to ensure a stable power supply and reduce the impact of power supply noise on the circuit.
In PCBA processing, anti-interference design is the key to improving the stability and reliability of electronic products. Through reasonable layout design, selection of appropriate materials, use of shielding technology and optimisation of power supply design, electromagnetic interference and radio frequency interference can be effectively reduced to improve the anti-interference capability of the circuit board. The implementation of these measures will help to improve product performance and reliability, thereby enhancing the market competitiveness of enterprises.