The Difference Between High-Speed PCB and Ordinary PCB

High-speed PCB (Printed Circuit Board) and ordinary PCB in the design, materials, manufacturing process and performance there are significant differences. This article will introduce the difference between high-speed PCB and ordinary PCB in detail, including design principles, material selection, manufacturing process and performance characteristics.

1. Design principles

1.1. Signal Integrity (SI) : High-speed PCB design needs to focus on signal integrity to ensure the stability and accuracy of the signal during transmission. Ordinary PCB design is mainly concerned with the functional realization of the circuit, and the requirements for signal integrity are relatively low.

1.2. Electromagnetic Compatibility (EMC) : High-speed PCB designs need to consider Electromagnetic compatibility to reduce Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI). In ordinary PCB designs, the requirements for electromagnetic compatibility are usually low.

1.3. Power Integrity (PI) : High-speed PCB design requires attention to power integrity to ensure power stability and reliability. In ordinary PCB design, the requirements for power integrity are relatively low.

1.4. Thermal management: High-speed PCB design needs to consider thermal management to ensure the stability and reliability of the circuit in high temperature environments. In ordinary PCB design, the requirements for thermal management are relatively low.

2. Material selection

2.1. Substrate materials: High-speed PCBS usually use high-performance substrate materials, such as FR-4, Rogers, PTFE, etc., which have lower dielectric constant (Dk) and loss factor (Df), helping to improve signal transmission speed and reduce signal loss. Common PCBS usually use lower-cost substrate materials, such as FR-2, FR-3, etc.

2.2. Copper foil: High-speed PCBS usually use thicker copper foil to improve current carrying capacity and reduce resistance. Ordinary PCBS usually use thinner copper foil to reduce costs.

2.3. Thermal conductive materials: In high-speed PCB design, it may be necessary to use thermal conductive materials, such as thermal conductive adhesives, thermal conductive pads, etc., to improve heat conduction performance. In ordinary PCB design, the use of thermal conductivity materials is relatively small.

3. Manufacturing process

3.1. Wiring: High-speed PCB wiring needs to follow specific rules, such as differential pair wiring, iso-length wiring, impedance matching, etc., to ensure the stability and accuracy of signal transmission. Ordinary PCB wiring is mainly concerned with the functional realization of the circuit.

3.2. Impedance control: High-speed PCB design requires impedance control to ensure the stability of the signal during transmission. In ordinary PCB design, the requirements for impedance control are relatively low.

3.3 Blind hole technology: High-speed PCB may need to use blind hole technology to achieve the connection between multiple layers. In common PCB design, the use of blind hole technology is relatively small.

3.4 Surface treatment: High-speed PCBS usually use surface treatment processes such as ENIG (Electroless Nickel Immersion Gold, non-electrolytic nickel immersion gold) to improve signal transmission performance and oxidation resistance. Ordinary PCB usually uses HASL (Hot Air Solder Leveling, hot air leveling) and other surface treatment processes.

4. Performance characteristics

4.1. Signal transmission speed: High-speed PCB has a higher signal transmission speed, which can meet the needs of high-speed data transmission. The signal transmission speed of ordinary PCBS is relatively low.

4.2. Signal loss: The signal loss of high-speed PCB is low, which helps to improve the stability and accuracy of signal transmission. The signal loss of ordinary PCBS is relatively high.

4.3. Electromagnetic compatibility: High-speed PCB has good electromagnetic compatibility, which can effectively reduce electromagnetic interference and RF interference. The electromagnetic compatibility of ordinary PCB is relatively poor.

4.4. Thermal performance: High-speed PCB has good thermal performance and can maintain stable operation in high temperature environment. The thermal performance of ordinary PCBS is relatively poor.

5. Application field

High-speed PCB is mainly used in high-speed data transmission, high-speed communication, high-performance computing, aerospace, military and other fields, these fields have high requirements for signal transmission speed, electromagnetic compatibility, thermal performance and so on. Ordinary PCB is mainly used in consumer electronics, household appliances, industrial control and other ordinary electronic products, these areas have relatively low requirements for signal transmission speed, electromagnetic compatibility, thermal performance and so on.

6. Summary

There are significant differences between high-speed PCB and ordinary PCB in design principles, material selection, manufacturing process and performance characteristics. High-speed PCB has higher signal transmission speed, lower signal loss, better electromagnetic compatibility and thermal performance, mainly used in high-speed data transmission, high-speed communication, high-performance computing and other high-end fields. Ordinary PCB is mainly used in consumer electronics, household appliances and other ordinary electronic products. Understanding the difference between high-speed PCBS and ordinary PCBS helps us choose the right type of PCB in practical applications to meet the needs of different products.