1. What Is Via Annular Ring?

The annular ring in PCB design refers to the copper area that remains around a drilled hole after plating. It's a critical parameter for ensuring proper electrical connection and mechanical strength of vias in printed circuit boards.

2. How Does The Calculator Work?

The calculator uses the annular ring formula:

Where:

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

Explanation: The annular ring represents the width of copper remaining around the drilled hole, which is crucial for ensuring proper electrical connection and mechanical integrity.

3. Importance Of Annular Ring Calculation

Details: Proper annular ring calculation is essential for PCB manufacturing reliability. Insufficient annular ring can lead to connection failures, while excessive annular ring may limit routing density.

4. Using The Calculator

Tips: Enter 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 are typical values for annular rings?
A: Typical annular ring values range from 0.05mm to 0.15mm, depending on PCB manufacturer capabilities and design requirements.

Q2: Why is annular ring important in PCB design?
A: Adequate annular ring ensures reliable electrical connections, prevents drill breakout, and provides mechanical strength to the via structure.

Q3: What happens if annular ring is too small?
A: Too small annular ring can cause connection failures, drill breakout, and reduced reliability in the finished PCB.

Q4: Are there industry standards for annular ring?
A: Yes, IPC standards provide guidelines for minimum annular ring requirements based on PCB class and application.

Q5: Can annular ring be different for different layers?
A: Yes, in multilayer PCBs, annular ring requirements may vary between inner and outer layers due to different manufacturing processes.