What does routing mean in PCB? What is the function?

In PCB (Printed Circuit Board) design, trace refers to the copper wires connecting various electronic components on the circuit board. Traces are the basic paths used to transmit electrical signals and power in PCBs. They form a connection network for electronic circuits between or on the layers of the circuit board.

The functions of wiring include:

Electrical Signal Transmission:

Wires are used to transmit electrical signals and connect electronic components such as microprocessors, memory, input/output devices, etc. to ensure the normal operation of the circuit.

Power Distribution: 

Traces are also responsible for distributing the power voltage to various parts of the circuit board to provide the required power to the electronic components.

Signal Integrity: 

Good wiring design helps maintain signal integrity, reduce signal reflection, crosstalk and delay, and improve circuit performance.

Electromagnetic Compatibility (EMC): 

Reasonable wiring can reduce electromagnetic interference (EMI), improve the electromagnetic compatibility of the circuit, and meet relevant regulations and standards.

Thermal Management: 

Trace design also involves thermal management. Proper trace layout and width can help dissipate heat and prevent local overheating.

Mechanical Stability: 

Traces also affect the mechanical stability of the PCB to a certain extent, especially when subjected to mechanical stress.

Assembly and Rrepair: 

Clear wiring layout helps identify different signal paths during assembly and repair, making it easier to diagnose faults and replace components.

Cost Control: 

Wiring design is also related to manufacturing costs. Reasonable design can reduce material use and reduce production costs.

Aesthetics: 

Although the main function of traces is technical, their layout on the PCB board also affects the appearance of the product.

Testing and Verification: 

The trace design should facilitate board testing and verification, including production testing and functional testing.

Adapt to Manufacturing Processes: 

Trace design needs to adapt to different PCB manufacturing processes, such as surface mount technology (SMT), wave soldering, etc.

Reliability: 

The layout and width of the traces will affect the reliability of the circuit. Reasonable design can reduce the failure rate and increase the service life of the product.

Differential Signal Transmission: 

For high-speed or high-precision circuits, the wiring design needs to support differential signal transmission to reduce interference between signals and improve signal quality.

Impedance Control: 

In some applications, such as radio frequency (RF) or high-speed digital circuits, traces require precise control of characteristic impedance to match component and transmission line requirements.

Interlayer Connection: 

The wiring may also need to realize the connection between different signal layers through through holes (Via) or buried holes (Buried Via).

Space Optimization: 

Within the limited PCB space, the trace design needs to efficiently utilize the space while avoiding overcrowding that leads to performance degradation.

Avoid Hot Spots: 

Through reasonable wiring design, hot spots caused by uneven power distribution can be avoided.

Reduce the Loop Area:

Reducing the loop area of the signal wiring helps reduce electromagnetic radiation and improve the signal's anti-interference ability.

Power Supply and Ground Wire Layout: 

In wiring design, the layout of power supply and ground wires (Ground) is crucial to power supply stability and noise reduction.

Signal Priority: 

In complex PCB designs, depending on the importance and characteristics of the signals, the routing design may need to prioritize the transmission paths of certain signals.

Test Points: 

The trace design should include necessary test points to facilitate subsequent circuit testing and fault diagnosis.

Thermal Expansion Considerations: 

In environments with large temperature changes, trace design should consider the thermal expansion coefficient of the material to avoid breakage due to thermal stress.

Design Rule Check: 

Trace design should comply with Design Rule Check (DRC) to ensure that the design meets the PCB manufacturer's requirements.

Adapt to Future Upgrades: 

Consider future upgrades and changes when designing, and the wiring should have a certain degree of flexibility and scalability.

Reduced Interconnect Length: 

Reducing trace length helps reduce signal latency and power consumption, especially in high-speed circuit designs.

Trace design is a key link to ensure PCB functionality, reliability and performance, requiring PCB designers to have deep professional knowledge and rich practical experience. By carefully designing traces, you can maximize the performance of electronic devices while reducing manufacturing and maintenance costs.