How to Check Gerber Files Before Manufacturing: Step-by-Step Guide

To check Gerber files before manufacturing, use a reliable Gerber viewer to visually inspect all PCB layers for accuracy and alignment. Also, verify file completeness, drill data, and layer stackup to ensure the design matches your specifications.

Syntax

Gerber files are a set of files with extensions like .gbr, .gtl, .gbl, and .drl that describe PCB layers and drill holes. To check them, you typically load these files into a Gerber viewer software.

Basic usage pattern:

Open Gerber Viewer → Load Gerber files (.gbr, .gtl, .gbl, .drl) → Inspect layers visually → Verify drill files → Check layer alignment and clearances

Each part means:

• Open Gerber Viewer: Use software like Gerbv, ViewMate, or online viewers.
• Load Gerber files: Import all relevant files for your PCB.
• Inspect layers visually: Check copper, solder mask, silkscreen, and other layers.
• Verify drill files: Confirm drill holes match design.
• Check alignment and clearances: Ensure layers line up and no traces are too close.

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Open Gerber Viewer
Load all Gerber files (.gbr, .gtl, .gbl, .drl)
Visually inspect each layer
Verify drill holes
Check layer alignment and clearances

Example

This example shows how to check Gerber files using the free Gerbv viewer:

• Download and install Gerbv from its official site.
• Open Gerbv and load your Gerber files by clicking File > Open Layer(s).
• Load all layers: top copper (.gtl), bottom copper (.gbl), solder mask, silkscreen, and drill files (.drl).
• Use zoom and pan to inspect traces, pads, and holes.
• Check for missing elements or misalignments.

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1. Download and install Gerbv
2. Open Gerbv
3. File > Open Layer(s)
4. Select all Gerber files (.gtl, .gbl, .gts, .gbs, .drl)
5. Inspect each layer visually
6. Verify drill holes and alignment

Output

Visual display of all PCB layers with drill holes correctly aligned and no missing features

Common Pitfalls

• Missing files: Forgetting to include drill files or solder mask layers causes manufacturing errors.
• Incorrect layer order: Loading layers in wrong order can mislead inspection.
• Misaligned layers: Layers not lining up cause shorts or open circuits.
• Unverified drill sizes: Drill holes too small or missing can break the PCB.
• Ignoring design rules: Not checking trace widths and clearances can cause failures.

Always double-check all files and use a trusted viewer.

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Wrong way:
Load only copper layers without drill files

Right way:
Load all layers including drill files
Verify alignment and drill sizes

Quick Reference

Step	What to Check	Why It Matters
Load all Gerber files	Include copper, solder mask, silkscreen, drill	Complete data for manufacturing
Visual inspection	Check traces, pads, holes	Detect missing or wrong features
Layer alignment	Ensure layers line up perfectly	Avoid shorts and open circuits
Drill verification	Confirm drill sizes and positions	Ensure correct hole sizes
Design rule check	Trace width and clearance	Prevent electrical failures

Key Takeaways

Always load and inspect all Gerber files including drill data before manufacturing.

Use a reliable Gerber viewer to visually check layer alignment and completeness.

Verify drill hole sizes and positions to avoid PCB defects.

Check design rules like trace width and clearance to ensure manufacturability.

Avoid common mistakes like missing files or misaligned layers by thorough review.