1. What is the Saturn PCB Trace Width Calculator?

Definition: This calculator determines the minimum width of a PCB trace needed to carry a specified current while keeping the temperature rise within acceptable limits.

Purpose: It helps PCB designers ensure proper current-carrying capacity and thermal performance of their circuit boards.

2. How Does the Calculator Work?

The calculator uses the IPC-2221 formula (Saturn PCB Tool version):

Where:

• \( Width \) — Trace width (mils)
• \( I \) — Current (amps)
• \( \Delta T \) — Temperature rise (°C)
• \( thickness \) — Copper thickness (oz/ft²)
• \( k \) — Constant (0.024 for internal, 0.048 for external layers)

Explanation: The formula calculates the minimum trace width needed to prevent excessive temperature rise for a given current.

3. Importance of Proper Trace Width

Details: Correct trace width ensures reliable PCB operation by preventing overheating, voltage drops, and potential trace failure.

4. Using the Calculator

Tips: Enter the current in amps, desired temperature rise (default 10°C), copper thickness (default 1 oz/ft²), and select layer type.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between internal and external layers?
A: External traces can dissipate heat better, hence the different k constant. Internal traces require more width for the same current.

Q2: What's a typical temperature rise limit?
A: 10°C is common, but higher values (20-30°C) may be acceptable depending on application.

Q3: How does copper thickness affect the result?
A: Thicker copper allows narrower traces for the same current, as shown by the negative exponent in the formula.

Q4: What units does this calculator use?
A: All units are in mils (1/1000 inch), amps, °C, and oz/ft² (copper weight).

Q5: Does this account for high-frequency effects?
A: No, this is for DC/low-frequency current only. High-frequency designs require additional considerations.