How to Generate Gerber and Drill Files in KiCad 7.0: A Complete Engineering Guide

Generating Gerber and drill files in KiCad 7.0 is the critical final step before sending your PCB design to fabrication. These standardized output files communicate your design intent to manufacturers with precision, ensuring accurate board production. This comprehensive guide walks you through the complete export workflow, covering optimal settings, best practices, and common pitfalls that can delay your production timeline.

Understanding Gerber and Drill File Fundamentals

Before diving into the export process, it’s essential to understand what these files represent. Gerber files (RS-274X format) are industry-standard 2D vector images that describe each layer of your PCB. Each copper layer, solder mask, silkscreen, and paste layer requires its own Gerber file. Drill files (Excellon format) define all hole positions, sizes, and types—including through-holes, vias, and mounting holes.

KiCad 7.0 generates these files natively, eliminating the need for third-party conversion tools. The software produces manufacturer-ready outputs that comply with IPC-2581 standards, ensuring compatibility with virtually any PCB fabrication house worldwide.

Pre-Export Checklist: Design Rule Check

Running a Design Rule Check (DRC) before exporting Gerber files is not optional—it’s mandatory for professional workflows. The DRC validates your design against manufacturing constraints and catches errors that could result in non-functional boards or production delays.

To execute the DRC in KiCad 7.0, open your PCB layout file (.kicad_pcb) and navigate to Inspect → Design Rules Checker. Address all errors and review warnings before proceeding. Common issues include insufficient clearances, unconnected nets, and drill-to-copper violations. Resolving these problems at this stage costs nothing; discovering them during fabrication wastes time and money.

Additionally, verify that all zone fills are current. Outdated zone fills can result in incorrect copper pour representations in your Gerber output, potentially causing opens or shorts in the manufactured board.

Step-by-Step Gerber File Generation

Open your completed PCB design file in KiCad 7.0’s PCB Editor. Access the Gerber export dialog through File → Fabrication Outputs → Gerbers (.gbr). This opens the Plot dialog window where you’ll configure all export parameters.

Output Directory Configuration

First, specify your output directory. Best practice dictates creating a dedicated subfolder—typically named “CAM” or “Gerber”—within your project directory. This organizational approach keeps fabrication files separated from design files, simplifying the handoff process to your manufacturer.

Layer Selection

Select the appropriate layers for export based on your board complexity. For a standard two-layer board, you’ll typically need:

• F.Cu (Front Copper)
• B.Cu (Back Copper)
• F.Paste (Front Solder Paste)
• B.Paste (Back Solder Paste)
• F.Silkscreen (Front Legend)
• B.Silkscreen (Back Legend)
• F.Mask (Front Solder Mask)
• B.Mask (Back Solder Mask)
• Edge.Cuts (Board Outline)

Multi-layer designs require additional inner layer selections. Ensure every copper layer in your stackup has a corresponding Gerber file.

Critical Plot Settings

Configure the following parameters for optimal output:

Plot Format: Gerber (the default and required format)

Coordinate Format: 4.6 format provides sufficient precision for most designs, offering resolution to 0.001mm. High-density designs may benefit from 4.7 format.

Use Protel Filename Extensions: Enable this option. Most manufacturers expect standard extensions (.GTL, .GBL, .GTS, etc.) rather than KiCad’s default naming convention. This small change prevents confusion and potential file rejection.

Generate Gerber Job File: Enable this to create a .gbrjob file containing metadata about your board, including layer stackup information. Modern manufacturers increasingly utilize this data for automated processing.

Subtract Soldermask from Silkscreen: Enable this option to prevent silkscreen ink from being applied over exposed pads, which improves solderability.

Check Zone Fills Before Plotting: Always enable this safety feature. If your zone fills are outdated, KiCad will prompt you to refill before generating outputs.

Use Drill/Place File Origin: Enable this for consistent coordinate referencing between Gerber and drill files—essential for accurate layer alignment during fabrication.

After configuring these settings, click the Plot button. KiCad generates individual Gerber files for each selected layer in your specified output directory.

Generating Excellon Drill Files

With the Plot dialog still open, click Generate Drill Files in the bottom-right corner. This opens the dedicated drill file configuration window.

Drill File Settings

Configure the following parameters:

Drill File Format: Excellon is the universal standard. Do not change this unless your manufacturer specifically requests an alternative format.

Drill Units: Millimeters provide better precision and are preferred by most international fabricators. Use inches only if your manufacturer explicitly requires them.

Zeros Format: Select “Decimal format” for maximum compatibility across different CAM systems.

Map File Format: PostScript or PDF map files provide visual verification of hole placement. While optional, these files help during quality inspection.

Drill Origin: Use the same origin as your Gerber files (Drill/Place File Origin) to maintain coordinate system consistency.

PTH and NPTH in Single File: For most manufacturers, keeping plated through-holes and non-plated through-holes in separate files is preferred. This allows independent processing of plated and mechanical holes.

Click Generate Drill File to create your Excellon outputs. KiCad produces .drl files containing all hole definitions and coordinates.

Verifying Your Output Files

Never submit fabrication files without verification. KiCad 7.0 includes a built-in Gerber viewer accessible through File → Open → Gerber Viewer, or you can use standalone tools like gerbv or online viewers provided by manufacturers.

Load all generated files and perform these verification checks:

Confirm all layers are present and properly aligned. Toggle layers on and off to verify copper, mask, and silkscreen relationships. Inspect the board outline for completeness—gaps in the Edge.Cuts layer cause manufacturing ambiguity.

Open drill files and verify hole counts match your design intent. Check that via sizes and pad holes correspond to your component footprints.

Packaging Files for Fabrication

Manufacturers expect a single compressed archive containing all fabrication files. Create a ZIP file including all Gerber files (.gbr or Protel extensions), drill files (.drl), and optionally the Gerber job file (.gbrjob).

Exclude unnecessary files such as KiCad project files, schematic sources, or intermediate outputs. A clean, minimal archive reduces confusion and expedites manufacturer review.

Common Export Errors and Troubleshooting

Even experienced engineers encounter issues during Gerber generation. Understanding common problems helps you resolve them quickly.

Missing Layers: If certain layers appear blank after export, verify that the corresponding design elements exist. Empty silkscreen layers, for instance, indicate no reference designators or graphics were placed on that board side.

Coordinate Misalignment: When drill holes don’t align with pad centers in your Gerber viewer, check that both Gerber and drill files use identical origin settings. Inconsistent origins cause systematic offsets that result in manufacturing defects.

Outdated Zone Fills: Manufacturers frequently report zone fill discrepancies. Always refill all zones (Edit → Fill All Zones or press ‘B’) immediately before export. Changes to traces or components can invalidate previous fills without visual indication.

Incorrect File Extensions: Some older CAM systems reject files with non-standard extensions. The “Use Protel Filename Extensions” option resolves most compatibility issues, but verify your manufacturer’s requirements if problems persist.

Advanced Considerations for Complex Designs

High-density interconnect (HDI) boards and designs with blind or buried vias require additional attention during file generation. KiCad 7.0 supports these advanced structures, but proper layer assignment in the drill file settings becomes critical.

For controlled impedance designs, include a fabrication drawing or README file specifying your stackup requirements, impedance targets, and dielectric specifications. While Gerber files define geometry, they don’t communicate these manufacturing constraints directly.

Conclusion

Generating Gerber and drill files in KiCad 7.0 requires attention to detail but follows a logical, repeatable workflow. By running DRC validation, configuring proper export settings, and verifying outputs before submission, you minimize production risks and accelerate your path from design to physical hardware.

The settings outlined in this guide align with industry standards accepted by major fabrication houses. However, always review your specific manufacturer’s requirements—some may have unique preferences for file naming, drill formats, or additional documentation. Establishing these parameters early in your design process ensures smooth handoffs throughout your product development cycle.