How to Export Gerber Files from Proteus

Proteus is a powerful electronic design automation (EDA) software suite widely used for circuit simulation, PCB design, and microcontroller simulation. One crucial step in the PCB manufacturing process is generating Gerber files, which are the standard format used by PCB fabrication houses to produce your designed board. This article will guide you through the process of exporting Gerber files from Proteus, ensuring that your PCB designs are ready for manufacturing.

Understanding Gerber Files

What are Gerber Files?

Gerber files are a set of computer-aided design (CAD) vector format files that contain information about different layers of a PCB design. They serve as the standard format for communicating PCB design data to manufacturing facilities.

Types of Gerber Files

Typically, a complete set of Gerber files for a PCB includes:

1. Top Copper Layer
2. Bottom Copper Layer
3. Top Solder Mask
4. Bottom Solder Mask
5. Top Silkscreen
6. Bottom Silkscreen
7. Drill File
8. Board Outline

Gerber File Formats

There are two main Gerber file formats:

1. RS-274X (Extended Gerber): The most common and recommended format
2. RS-274D: An older format, less commonly used today

Proteus supports the export of RS-274X format Gerber files, which is the industry standard.

Preparing Your Proteus PCB Design

Before exporting Gerber files, ensure your PCB design is complete and error-free.

Design Checklist

1. All components are placed correctly
2. Traces are properly routed
3. No design rule violations
4. Board outline is defined
5. Layers are correctly assigned
6. Vias and pads are properly sized
7. Silkscreen text is legible and not overlapping with pads

Running Design Rule Checks (DRC)

Proteus provides a Design Rule Check feature to verify your PCB design:

1. Go to "Tools" > "Design Rule Check"
2. Review and set appropriate rules
3. Run the check and address any errors or warnings

Configuring Gerber Export Settings

Proper configuration of export settings is crucial for generating accurate Gerber files.

Accessing Export Settings

1. Open your PCB design in Proteus
2. Go to "Output" > "Generate Gerber/Excellon Files"

Key Export Settings

Layer Selection

Ensure all necessary layers are selected for export:

• Top Copper
• Bottom Copper
• Top Solder Mask
• Bottom Solder Mask
• Top Silkscreen
• Bottom Silkscreen
• Board Outline
• Drill File

Exporting Gerber Files

Once your settings are configured, follow these steps to export the Gerber files:

1. Click "Generate Gerber Files" in the export dialog
2. Choose a destination folder for the files
3. Review the list of files to be generated
4. Click "OK" to start the export process

File Naming Conventions

Use clear and consistent naming conventions for your Gerber files. For example:

• ProjectName_TopCopper.gbr
• ProjectName_BottomCopper.gbr
• ProjectName_TopSolderMask.gbr
• ProjectName_BottomSolderMask.gbr
• ProjectName_TopSilkscreen.gbr
• ProjectName_BottomSilkscreen.gbr
• ProjectName_BoardOutline.gbr
• ProjectName_DrillFile.drl

Verifying Exported Gerber Files

After exporting, it's crucial to verify the Gerber files to ensure they accurately represent your PCB design.

Using Gerber Viewers

Several free Gerber viewers are available:

1. GerbView (included with KiCad)
2. gerbv
3. CAM350

Verification Steps

1. Open each Gerber file in the viewer
2. Check that all layers are present and correctly aligned
3. Verify component placement and orientation
4. Ensure all traces are present and connected
5. Check that the board outline is correct
6. Verify drill holes are in the right locations

Common Issues and Troubleshooting

Missing Layers

If layers are missing in the exported files:

1. Return to the export settings
2. Ensure all necessary layers are selected
3. Re-export the files

Misaligned Layers

For misaligned layers:

1. Check the origin point in your PCB design
2. Ensure all layers use the same coordinate system
3. Re-export with corrected alignment

Incorrect Drill File

If the drill file is incorrect:

1. Verify drill sizes in your PCB design
2. Check drill file export settings
3. Re-generate the drill file

Resolution Issues

For problems with resolution or detail:

1. Increase the export resolution in settings
2. Ensure your design uses appropriate track and gap sizes
3. Re-export with higher resolution settings

Best Practices for Gerber File Generation

1. Use consistent units throughout your design (preferably millimeters)
2. Include a board outline in a separate Gerber file
3. Generate a separate drill file in Excellon format
4. Use descriptive file names for each Gerber file
5. Always verify exported files before sending to fabrication
6. Keep your Proteus software updated to the latest version
7. Save your export settings for future use on similar projects

Advanced Gerber Export Techniques

Panelization

For efficient production of multiple boards:

1. Create a panelized layout in Proteus
2. Export Gerber files for the entire panel
3. Include panel outline and fiducial marks

Custom Apertures

For special pad shapes or complex designs:

1. Define custom apertures in Proteus
2. Ensure these are included in the Gerber export settings
3. Verify custom apertures in the Gerber viewer

Copper Pour Areas

When using large copper pour areas:

1. Ensure proper thermal relief settings
2. Verify copper pour connectivity in the Gerber files
3. Check for any isolated copper islands

Multi-layer Boards

For boards with more than two copper layers:

1. Carefully manage layer stack-up in Proteus
2. Export Gerber files for each copper and dielectric layer
3. Provide clear layer stack-up information to the fabricator

Frequently Asked Questions

Q1: What's the difference between Gerber and Excellon files?

A1: Gerber files contain information about the PCB layers (copper, solder mask, silkscreen, etc.), while Excellon files specifically contain drill information. Excellon files define the location and size of holes to be drilled in the PCB. Both file types are typically needed for PCB fabrication.

Q2: How can I ensure my Gerber files are compatible with my chosen PCB manufacturer?

A2: To ensure compatibility:

1. Check your manufacturer's specific requirements for Gerber files
2. Use the RS-274X Gerber format, which is widely accepted
3. Verify your export settings match the manufacturer's specifications
4. Send a test submission to the manufacturer for verification before full production

Q3: Why are some of my traces missing in the exported Gerber files?

A3: Missing traces can occur due to:

1. Incorrect layer assignment in your Proteus design
2. Export settings excluding certain layers
3. Traces being too thin for the selected export resolution

To resolve this, check your layer assignments, export settings, and trace widths. Then re-export the Gerber files.

Q4: How do I include non-plated holes in my Gerber files?

A4: To include non-plated holes:

1. Design these holes on a separate layer in Proteus
2. During Gerber export, include this layer as a separate file
3. Clearly communicate to your PCB manufacturer which holes should be non-plated
4. Some manufacturers may require these to be specified in a separate drill file

Q5: Can I modify Gerber files after exporting them from Proteus?

A5: While it's possible to modify Gerber files using specialized Gerber editing software, it's not recommended. Any changes should ideally be made in the original Proteus design and then re-exported. This ensures consistency between your design and the manufactured board. If you must make changes to Gerber files, use caution and always verify the modified files thoroughly before submitting for fabrication.