1. What is PCB Annular Ring?

The annular ring in PCB design refers to the copper area that surrounds a drilled hole. It's a critical parameter that ensures proper electrical connection between different layers of the PCB and provides mechanical support for component leads.

2. How Does the Calculator Work?

The calculator uses the annular ring formula:

Where:

• \( D_{pad} \) — Pad diameter (units)
• \( D_{hole} \) — Hole diameter (units)

Explanation: The annular ring width is calculated as half the difference between the pad diameter and the hole diameter, representing the copper area surrounding the hole.

3. Importance of Annular Ring Calculation

Details: Proper annular ring width is crucial for PCB reliability. Insufficient annular ring can lead to connection failures during drilling or soldering, while excessive annular ring may limit routing space and increase manufacturing costs.

4. Using the Calculator

Tips: Enter both pad diameter and hole diameter in the same units. Ensure the pad diameter is larger than the hole diameter for a valid calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the minimum recommended annular ring width?
A: Typically 0.15mm (6 mil) for standard PCBs, but this varies based on manufacturer capabilities and IPC standards.

Q2: Why is annular ring important for PCB reliability?
A: Adequate annular ring ensures proper electrical connection, provides mechanical support, and prevents breakout during drilling operations.

Q3: What happens if the annular ring is too small?
A: Small annular rings can lead to connection failures, drill breakout, and reduced mechanical strength of the PCB.

Q4: Are there different requirements for plated vs non-plated holes?
A: Yes, plated through holes typically require larger annular rings than non-plated holes due to the plating process requirements.

Q5: How does annular ring affect manufacturing yield?
A: Proper annular ring design significantly improves manufacturing yield by reducing drill breakout and connection failures.