What are Gerber Files?

Gerber files are a standard file format used in the printed circuit board (PCB) industry to describe the layout of a PCB. They are named after the Gerber Scientific Instrument Company, which developed the format in the 1960s. Gerber files are used to communicate the design of a PCB between the designer and the manufacturer, ensuring that the final product matches the intended design.

Gerber files contain information about the copper layers, solder mask, silkscreen, and other features of a PCB. They are generated from the PCB design software used to create the board layout, such as Altium Designer, Eagle, or KiCad.

Importance of Gerber Files

Gerber files play a crucial role in the PCB manufacturing process. They provide the necessary information for the manufacturer to fabricate the PCB according to the designer’s specifications. Without accurate Gerber files, the manufactured PCB may not function as intended, leading to costly rework or redesign.

Gerber files ensure that the PCB manufacturer has all the required data to produce the board, including:

• Copper layer patterns
• Drill hole locations and sizes
• Solder mask and silkscreen layouts
• Board outline and dimensions

By using a standardized file format like Gerber, designers and manufacturers can communicate effectively, reducing the chances of errors and misinterpretations.

Step-by-Step Guide to Generate Gerber Files

Generating Gerber files is a straightforward process that can be completed using most PCB design software. In this guide, we will walk through the steps to generate Gerber files using Altium Designer, a popular PCB design tool. The process may vary slightly for other software, but the general principles remain the same.

Step 1: Complete Your PCB Design

Before generating Gerber files, ensure that your PCB design is complete and error-free. This includes:

• Placing and routing all components
• Defining the board outline and dimensions
• Adding solder mask and silkscreen layers
• Specifying drill holes and vias

Thoroughly review your design for any mistakes or design rule violations. It’s essential to catch and correct any issues before proceeding to Gerber File Generation.

Step 2: Access the Fabrication Outputs

In Altium Designer, navigate to the “File” menu and select “Fabrication Outputs.” This will open the Fabrication Outputs window, where you can configure the settings for generating Gerber files.

Step 3: Configure the Gerber File Settings

In the Fabrication Outputs window, you’ll find various settings for generating Gerber files. The most important settings to consider are:

• Format: Select the appropriate Gerber file format. The most common format is RS-274X, also known as Extended Gerber.
• Layers: Choose which layers to include in the Gerber files. Typically, you’ll include all copper layers, solder mask, silkscreen, and drill files.
• Filename: Specify the naming convention for the generated Gerber files. It’s essential to use a clear and consistent naming scheme to avoid confusion.

Adjust any other settings according to your manufacturer’s requirements or your project’s specific needs.

Step 4: Generate the Gerber Files

Once you have configured the settings, click on the “OK” button to generate the Gerber files. Altium Designer will create a separate file for each layer specified in the settings.

The generated Gerber files will be saved in the project folder, usually in a dedicated “Outputs” or “Gerber” subfolder.

Step 5: Review and Verify the Gerber Files

After generating the Gerber files, it’s crucial to review and verify them for accuracy. Most PCB design software, including Altium Designer, includes a Gerber viewer that allows you to visually inspect the generated files.

Open each Gerber file and check for any discrepancies or errors, such as:

• Missing or incorrect copper patterns
• Incorrect drill hole sizes or locations
• Solder mask or silkscreen issues
• Board outline and dimension inaccuracies

If you find any issues, return to your PCB design, make the necessary corrections, and regenerate the Gerber files.

Step 6: Package and Send the Gerber Files

Once you have verified the accuracy of your Gerber files, package them together in a compressed format, such as a ZIP file. Include any additional files or information required by your PCB manufacturer, such as a readme file with special instructions or a bill of materials (BOM).

Send the packaged Gerber files to your PCB manufacturer, either through their website or by email. Most manufacturers will provide specific instructions on how to submit your files.

Common Gerber File Extensions and Their Meanings

Gerber files use various file extensions to identify the different layers and features of a PCB. Understanding these extensions is essential for communicating with your PCB manufacturer and ensuring that all necessary files are included. Some common Gerber file extensions and their meanings are:

Note that the exact extensions may vary depending on the PCB design software and the naming convention used. Always consult with your PCB manufacturer for their specific requirements.

Tips for Successful Gerber File Generation

To ensure a smooth PCB manufacturing process, consider the following tips when generating Gerber files:

1. Use a consistent naming convention: Adopt a clear and consistent naming convention for your Gerber files to avoid confusion and errors.

2. Include all necessary layers: Make sure to include all required layers in your Gerber files, such as copper layers, solder mask, silkscreen, and drill files.

3. Verify the accuracy of your files: Always review and verify your Gerber files for accuracy before sending them to your PCB manufacturer.

4. Communicate with your manufacturer: Consult with your PCB manufacturer for their specific requirements, such as file formats, naming conventions, and any additional files they may need.

5. Keep a backup of your files: Store a copy of your Gerber files and PCB design files in a secure location for future reference or revisions.

Frequently Asked Questions (FAQ)

1. What is the difference between Gerber files and ODB++ files?
   Gerber files and ODB++ (Open Database++) files are both used to communicate PCB design information to manufacturers. However, ODB++ is a more comprehensive and intelligent format that includes additional information, such as netlist data and component placement details. Gerber files are simpler and more widely supported, making them the most common choice for PCB manufacturing.

2. Can I generate Gerber files from any PCB design software?
   Most PCB design software, including Altium Designer, Eagle, KiCad, and OrCAD, support Gerber file generation. However, the specific process and settings may vary between software. Consult your software’s documentation or support resources for guidance on generating Gerber files.

3. What should I do if my PCB manufacturer reports issues with my Gerber files?
   If your PCB manufacturer reports issues with your Gerber files, first verify that you have included all necessary files and that they adhere to the manufacturer’s requirements. Review your files for accuracy and make any necessary corrections in your PCB design software. If the issue persists, communicate with your manufacturer to resolve the problem and obtain further guidance.

4. How can I ensure my Gerber files are compatible with my PCB manufacturer’s requirements?
   To ensure compatibility, consult with your PCB manufacturer for their specific requirements, such as file formats, naming conventions, and any additional files they may need. Many manufacturers provide Gerber file generation guidelines or templates that you can follow. When in doubt, communicate with your manufacturer to clarify their expectations.

5. What are the consequences of submitting incorrect or incomplete Gerber files?
   Submitting incorrect or incomplete Gerber files can lead to manufacturing delays, additional costs, and even non-functional PCBs. Inaccurate Gerber files may cause the manufacturer to produce boards that do not match your intended design, resulting in the need for rework or redesign. To avoid these issues, always thoroughly review and verify your Gerber files before submitting them to your manufacturer.

Conclusion

Generating accurate Gerber files is a critical step in the PCB manufacturing process. By following the step-by-step guide outlined in this article and adhering to best practices, you can ensure that your PCB design is accurately communicated to your manufacturer, resulting in a functional and high-quality printed circuit board.

Remember to complete your PCB design, configure the appropriate Gerber file settings, generate the files, review and verify them for accuracy, and package them for submission to your manufacturer. By understanding common Gerber file extensions and following the tips provided, you can streamline your workflow and minimize the risk of errors.

As PCB design and manufacturing technologies continue to evolve, staying informed about the latest standards and best practices for Gerber file generation will help you stay competitive and ensure the success of your projects.