I. The Nature and Classification of GND (Core Content for Layout Engineer Training)

1. The nature of GND

The essence of GND (ground) is... Provide a low-impedance return path for the circuit. Ensure that the current returns steadily to the negative terminal of the power supply, while also serving as a connection between various components in the circuit. 0V voltage reference point If the ground wire is improperly designed, impedance can cause voltage drops, noise interference, and even signal distortion.

2. Classification and Design Considerations for GND

3. Common Issues and Solutions in GND Layout

Question 1: Signal Crosstalk ​

Reason Directly connecting digital ground to analog ground leads to noise coupling.

Solve : Adopted Regionally pour copper Use magnetic beads for isolation in the high-frequency range (e.g., 100Ω at 100 MHz).

Question 2: Ground-level cracks ​

Reason Via or trace routing splits the ground plane, creating a high-impedance “waistline.”

Solve Avoid crossing critical signal traces over partition boundaries; use them when necessary. Bypass capacitor (Such as 0.1 μF) provides a high-frequency return path.

Question 3: Geographical Offset ​

Reason The impedance of the high-current path causes the reference voltage to rise.

Solve The power ground should have a separate trace and be widened (e.g., when the current is 100A, the trace width should be ≥15mm). Use... Star-grounded Reduce common-mode impedance.

II. Customer Communication Training Guide

1. Core Principles of Communication

Professionalism Explain the GND design principles using technical terms (e.g., “single-point grounding suppresses common-mode noise”) to enhance customer trust.

Empathy Proactively inquire about customer needs (e.g., “Is your product facing high-frequency interference issues?”) and guide the discussion toward identifying pain points.

Simple visualization Use simulation diagrams or real-world case studies to illustrate the strengths and weaknesses of ground wire designs (e.g., by comparing EMC test results).

2. Common Customer Scenario Response Strategies

3. Techniques for Handling Customer Objections

When a customer questions the complexity of the design ：

Respond “Although GND separation may seem complicated, it can help reduce the cost of later rectifications. For example, one customer’s failure to properly separate grounds led to an EMC test failure, increasing rectification costs by a factor of five.”

When a customer requests combining ground wires to save money, ：

Respond “We can start by using a simplified design to prototype-test, leaving space for isolation components, and then decide whether to upgrade based on the test results.”

III. Leakin Technology Case Studies and Practical Recommendations

1. Reference to Success Stories

Industrial Motor Controller Project ：

Challenge The motor's power noise interferes with the ADC sampling.

Solution : Adopted Layered ground plane (Power formation is isolated from the signal formation), and the sampling error has been reduced from ±5% to ±0.1%.

Customer Feedback "Ling Kun's GND design avoids the risk of product recalls."

2. Internal Design Specifications (Practical Checklist)

✅ Digital/analog ground partitioning with a spacing of ≥2mm.

✅ The width of the power ground plane is calculated based on the current (e.g., for 10A, it should be 3mm with a copper thickness of 1oz).

✅ Keep the solid ground plane intact beneath critical signals (such as clocks).

✅ All ground wires are ultimately connected to the power ground at a single point.

Conclusion GND design is the cornerstone of PCB reliability. Leakin Technology helps engineers strike a balance between performance and cost in complex scenarios through systematic training and customer communication strategies. This document will be continuously updated with summaries of experiences gained from actual projects.

Document Version: V1.1 | Updated on: 2019-02-29 | Copyright © Shenzhen Leakin Technology Co., Ltd.