1. What is PCB Annular Ring?

The annular ring on a PCB refers to the copper area that surrounds a drilled hole, providing the connection point between the hole and the copper trace. It is a critical parameter in PCB design that ensures proper electrical connectivity and mechanical strength.

2. How Does the Calculator Work?

The calculator uses the annular ring formula:

Where:

• \( Pad\ Diameter \) — Outer diameter of the copper pad (mm)
• \( Hole\ Diameter \) — Diameter of the drilled hole (mm)
• \( Ring\ Width \) — Distance from hole edge to pad edge (mm)

Explanation: The annular ring width represents the copper area available for making reliable electrical connections after drilling.

3. Importance of Annular Ring Calculation

Details: Proper annular ring sizing is crucial for PCB reliability. Insufficient annular ring can lead to connection failures during drilling or thermal stress, while excessive annular ring may reduce routing space.

4. Using the Calculator

Tips: Enter pad diameter and hole diameter in millimeters. Ensure pad diameter is larger than hole diameter for valid calculation. Typical values range from 0.3mm to 2.0mm for pad diameter and 0.1mm to 1.0mm for hole diameter.

5. Frequently Asked Questions (FAQ)

Q1: What is the minimum annular ring requirement?
A: IPC standards typically require minimum 0.05mm annular ring, but manufacturer capabilities and design requirements may vary.

Q2: Why is annular ring important in PCB manufacturing?
A: It ensures reliable electrical connections, provides mechanical support for components, and accommodates drilling tolerances.

Q3: What happens if annular ring is too small?
A: Small annular rings can lead to broken connections, poor solderability, and reduced reliability under thermal stress.

Q4: Does annular ring affect signal integrity?
A: In high-frequency designs, annular ring size can affect impedance matching and signal quality, particularly for vias.

Q5: How does annular ring relate to via design?
A: For vias, annular ring determines the connection reliability between layers and affects the overall PCB stackup design.