1. What is Annular Ring?

The annular ring is the copper area between the edge of a drilled hole and the edge of the pad in PCB design. It is a critical parameter that ensures proper electrical connection and mechanical strength for through-hole components.

2. How Does the Calculator Work?

The calculator uses the standard annular ring formula:

Where:

• \( Pad\ Diameter \) — Outer diameter of the copper pad (mm)
• \( Hole\ Diameter \) — Diameter of the drilled hole (mm)

Explanation: The annular ring represents the radial distance from the hole wall to the pad edge, calculated as half the difference between pad and hole diameters.

3. Importance of Annular Ring Calculation

Details: Proper annular ring width is essential for reliable PCB manufacturing. Insufficient annular ring can lead to breakout, poor solderability, and electrical failures. IPC standards specify minimum annular ring requirements based on PCB class and application.

4. Using the Calculator

Tips: Enter pad diameter and hole diameter in millimeters. Both values must be positive numbers, and pad diameter must be larger than hole diameter for valid calculation.

5. Frequently Asked Questions (FAQ)

Q1: What are typical IPC annular ring requirements?
A: IPC-6012 Class 2 typically requires minimum 0.05mm annular ring, while Class 3 may require 0.075mm or more depending on the application.

Q2: Why is annular ring important in PCB design?
A: Adequate annular ring ensures reliable electrical connections, prevents breakout during drilling, and provides sufficient area for solder joint formation.

Q3: What happens if annular ring is too small?
A: Small annular rings can cause drill breakout, poor solderability, reduced mechanical strength, and potential electrical opens or intermittent connections.

Q4: How does annular ring affect manufacturing yield?
A: Proper annular ring design improves manufacturing yield by reducing drill registration issues and ensuring reliable plating and soldering processes.

Q5: Are there different requirements for different hole types?
A: Yes, plated through holes, non-plated holes, and via holes may have different annular ring requirements based on their function and manufacturing process.