{"id":2438,"date":"2025-02-19T18:22:09","date_gmt":"2025-02-19T10:22:09","guid":{"rendered":"https:\/\/www.jingpengpcb.com\/?p=2438"},"modified":"2026-10-02T19:42:26","modified_gmt":"2026-10-02T11:42:26","slug":"three-special-routing-techniques-for-pcb-layout","status":"publish","type":"post","link":"https:\/\/www.jingpengpcb.com\/en\/blog\/three-special-routing-techniques-for-pcb-layout\/","title":{"rendered":"Three Special Tracing Techniques for PCB Layout"},"content":{"rendered":"

This article will provide a detailed discussion of three aspects: right-angle traces, differential traces, and serpentine traces.PCB Layout<\/a>Three Special Routing Techniques.<\/p>\n

\"PCB<\/p>\n

I. Right-Angle Tracing<\/h2>\n

The impact of right-angle traces on signals is primarily reflected in three aspects.<\/p>\n

1. Capacitive Load at the Corner<\/h3>\n

First, a corner can be treated as a capacitive load on a transmission line, which helps slow down the signal\u2019s rise time and improve signal quality.<\/p>\n

2. Impedance Discontinuities and Signal Reflections<\/h3>\n

Second, impedance discontinuities can cause signal reflections, which affect the stable transmission of signals. Therefore, in PCB design, it is important to avoid excessive right-angle turns, especially in high-speed circuits.<\/p>\n

3. EMI Caused by Right-Angle Traces<\/h3>\n

Finally, it is worth noting the electromagnetic interference (EMI) issues caused by right-angle corners. In high-frequency, high-speed circuit design, even the smallest right-angle corners can become a key source of high-speed issues.<\/p>\n

II. Differential Signaling<\/h2>\n

1. Advantages of Differential Signals<\/h3>\n

A differential trace is a pair of transmission lines carrying opposite signals, used to cancel out noise and improve signal quality. Differential signals offer the following advantages over single-ended signal traces:<\/p>\n

    \n
  • It has strong immunity to interference and can effectively cancel out common-mode noise.<\/li>\n
  • It effectively suppresses EMI and reduces electromagnetic radiation.<\/li>\n
  • It provides precise timing and is suitable for circuits with low-amplitude signals.<\/li>\n<\/ul>\n

    2. Key Considerations in Differential Signal Design<\/h3>\n

    When designing differential traces, the following principles should be followed:<\/p>\n

      \n
    • Increase the spacing between parallel segments and reduce the coupling length to prevent signal crosstalk.<\/li>\n
    • Use differential traces with ribbon cables or buried microstrip lines to reduce transmission delay.<\/li>\n
    • For high-speed signal lines and those with strict timing requirements, avoid using serpentine routing.<\/li>\n<\/ul>\n

      III. Serpentine Line<\/h2>\n

      1. The Need to Adjust the Delay<\/h3>\n

      A serpentine trace is a routing method used to adjust the delay to meet system timing design requirements. Key parameters of a serpentine trace include the parallel coupling length (LP) and the coupling distance (s).<\/p>\n

      As signals travel along a serpentine trace, coupling occurs between parallel segments, creating a differential-mode signal. This can result in reduced transmission delay and degraded signal quality.<\/p>\n

      2. Recommendations for Handling Serpentine Wires<\/h3>\n

      When working with serpentine traces, layout engineers can follow these recommendations:<\/p>\n

        \n
      • Increase the distance (S) between parallel line segments to at least 3H to minimize the coupling effect between the segments as much as possible.<\/li>\n
      • Reduce the coupling length (Lp) to prevent crosstalk saturation.<\/li>\n
      • Avoid routing traces in a zigzag pattern over a small area, especially for high-speed circuits.<\/li>\n
      • Snake-like routing at any angle can be used to reduce mutual coupling.<\/li>\n
      • In high-speed PCB design, serpentine traces are primarily used for timing matching and are not suitable for filtering or noise suppression.<\/li>\n<\/ul>\n

        By selecting and optimizing the routing strategies described above, PCB designers can better meet circuit performance and stability requirements, ensuring the reliability and performance of electronic devices.<\/p>\n

        In PCB design, routing strategies are a key factor; right-angle routing, differential routing, and serpentine routing each have their own applications and advantages. Choosing the appropriate routing strategy will help ensure the circuit\u2019s performance and stability.<\/p>\n

        FAQs (Frequently Asked Questions)<\/strong><\/h2>\n

        What is a differential signal?<\/strong><\/p>\n

        A differential signal is a pair of signals that have the same amplitude but are out of phase, used to improve signal quality and cancel out noise.<\/p>\n

        Why Should You Avoid Right-Angle Traces?<\/strong><\/p>\n

        Right-angle traces can cause signal reflections and electromagnetic interference, which can affect circuit performance.<\/p>\n

        What is the role of serpentine traces in PCB design?<\/strong><\/p>\n

        The serpentine line is used to adjust the delay to meet the system's timing design requirements.<\/p>\n

        How do you choose the right routing strategy?<\/strong><\/p>\n

        The choice of routing strategy should be evaluated based on the specific circuit requirements and performance needs, following best practices.<\/p>\n

        What is the difference between differential signaling and single-ended signaling?<\/strong><\/p>\n

        Differential traces use two opposite signals for transmission, while single-ended traces use only one signal line for transmission.<\/p>","protected":false},"excerpt":{"rendered":"

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