How to Change PCB Gerber File

This step-by-step tutorial explains how to change a PCB Gerber file in Altium Designer CAM Editor. In this example, a new copper trace and a pad are added on the top layer, and the corresponding drill hole is created as well.

Quick Guide

Before You Start

Gerber editing can be useful when a small PCB manufacturing change is needed after Gerber output has already been generated. This guide focuses on a simple example only.

  • Software used in this example: Altium Designer CAM Editor
  • Modification example: add a pad, a drill hole, and a copper trace
  • Output result: updated Gerber files and NC Drill data
Important: If your PCB change affects electrical connectivity, controlled impedance, design rules, or multilayer relationships, it is usually better to edit the original PCB design file and regenerate the complete fabrication data package instead of changing Gerber files directly.

Step 1: Open Altium Designer and create a new CAM file

Start Altium Designer and create a new CAM document for PCB Gerber editing.

Open Altium Designer and create a new CAM file for PCB Gerber editing

Step 2: Import the original Gerber and drill files

Import the original Gerber files and the NC drill file into the CAM Editor so the existing PCB data can be edited.

Import original PCB Gerber files and NC drill files into Altium CAM Editor

Step 3: Set the .GTL file as the current working layer

Select the .GTL (Gerber Top Layer) file as the current layer, because the new copper feature will be added to the top layer.

Set GTL Gerber top layer as the current layer in CAM Editor

Step 4: Place a new pad on the top layer

From the Place menu, select Flash and put a new pad at the desired location in the PCB window.

Place a new pad on the PCB top layer in Altium CAM Editor

Step 5: Add a drill hole at the center of the new pad

Switch to the Drill Hole window, change the CAM Editor to the NC Editor, then use Place > Drill > Drillpoint to add a drill hole at the center of the new pad.

Add a new drill hole to the center of the new PCB pad in NC Editor

Step 6: Add a new copper trace connected to the pad

Switch back to CAM Editor, select the .GTL layer again, and use the Place menu to add a new copper line connected to the new pad.

Add a new copper wire connected to the new PCB pad on the GTL layer

Step 7: Export the updated Gerber file for PCB fabrication

After finishing the modification, export the updated Gerber file and corresponding drill data for PCB fabrication.

Export the updated PCB Gerber files after editing in Altium Designer
Tip: Before sending the updated fabrication data for production, check the new pad size, hole position, copper connection, and surrounding clearance carefully.
Related Resources

You may also find the following PCB fabrication resources helpful when preparing or checking your files.

FAQ

Frequently Asked Questions About Changing PCB Gerber Files

Can I modify a PCB Gerber file without the original PCB design file?

Yes. Small changes can be made directly in Gerber data by using a CAM editor. However, if the change affects connectivity, impedance, clearance, or multilayer relationships, it is usually better to edit the original PCB design source file and regenerate the full fabrication package.

What software can be used to change a PCB Gerber file?

A CAM editor such as Altium Designer CAM Editor can be used to modify Gerber data, add copper features, place pads, and update drill information.

Can I add a pad and a drill hole directly in Gerber data?

Yes. You can add a pad in the Gerber layer and add the corresponding hole in the NC drill data. After that, you should review the modified area carefully before fabrication.

When should I avoid changing Gerber files directly?

You should avoid direct Gerber editing when the design change is large, or when it may affect electrical performance, net integrity, controlled impedance, or layer stackup relationships.

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