How to Use CAM350 with Gerber Files: Step-by-Step Tutorial [2026]

Working with CAM350 Gerber files is something I do almost daily as a PCB engineer, and I’ve learned that proper CAM processing can mean the difference between a smooth production run and costly fabrication delays. Whether you’re verifying design output before sending to a fab house or preparing manufacturing files as a CAM engineer, understanding how to use Gerber CAM350 workflows is essential knowledge.

This comprehensive tutorial walks through the complete process of importing, verifying, editing, and exporting Gerber files in CAM350. I’ll share practical tips that come from real production experience, covering everything from basic import procedures to advanced DFM analysis techniques.

Understanding Gerber Files and CAM350

Before diving into the workflow, let’s clarify what we’re working with. Gerber files are the industry standard format for communicating PCB fabrication data. Each file represents a single layer of your PCB—copper layers, soldermask, silkscreen, paste mask, and mechanical outlines. When you send files to a manufacturer, they use CAM software to process these files for production.

CAM350 Gerber processing serves two primary audiences: PCB designers verifying their output before release, and fabrication engineers preparing data for production. The software handles import, verification, editing, panelization, and output generation—essentially everything needed to transition from design to manufacturing.

Gerber Format Types Supported in CAM350

Format	Description	Aperture Handling
RS-274X (Extended Gerber)	Modern standard with embedded apertures	Self-contained, no separate file needed
RS-274D (Standard Gerber)	Legacy format requiring separate aperture file	Requires external aperture list
Fire9000	Proprietary format with embedded apertures	Self-contained
Barco DPF	Specialized format	Format-specific handling

For new designs, RS-274X is the recommended format. It embeds aperture definitions within the file itself, eliminating the compatibility issues that plague RS-274D workflows. If you’re exporting from modern CAD tools like Altium Designer, KiCad, or Cadence Allegro, always select RS-274X.

Step 1: Importing Gerber Files into CAM350

The import process is where many engineers first encounter problems. CAM350 offers multiple import methods, each suited to different situations.

Method A: Auto Import (Recommended for Complete Packages)

Auto Import is the fastest way to load a complete Gerber package when all files are in a single directory:

1. Launch CAM350 and select File → Import → AutoImport
2. Navigate to the directory containing your Gerber files
3. CAM350 scans the folder and identifies file types automatically
4. Review the file list—by default, do not select drill files yet (import these separately)
5. Click Finish to complete the import

Important tip: Import drill data separately using File → Import → Drill Data. This gives you better control over drill format settings, particularly the Leading/Trailing zero suppression that causes alignment issues if mismatched.

Method B: Manual Gerber Import (For Selective Loading)

When you need precise control over what gets loaded:

1. Select File → Import → Gerber Data
2. Choose the specific files you want to import
3. In the import dialog, configure:
   1. Units (Imperial/Metric)
   1. Format (typically 2:4 or 2:5 for inches, 3:3 for metric)
   1. Zero suppression (Leading or Trailing)
   1. Aperture source (Auto-detect for RS-274X)

Import Settings Reference Table

Setting	Common Values	Notes
Units	Inches / Millimeters	Must match source CAD export
Integer Places	2-4	Defines coordinate precision
Decimal Places	3-6	Higher = more precision
Zero Suppression	Leading / Trailing	Must match export settings exactly
Aperture Format	RS-274X / Auto-detect	Use Auto-detect when unsure

Step 2: Importing Drill Files Separately

Drill file handling in Gerber CAM350 workflows requires special attention because misaligned drill data causes catastrophic fabrication errors.

1. Go to File → Import → Drill Data
2. Click the browse button and select your drill file (.drl, .txt, .xln, or .exc)
3. Choose All Files in the filter to see all available files
4. Select the correct format:
   1. Leading zero suppression (most common)
   1. Trailing zero suppression
   1. Explicit decimal point
5. Click OK to import

After import, visually verify drill alignment by overlaying the drill layer on your top copper layer. Pad centers should align perfectly with drill hits. If they don’t, you have a format mismatch that needs correction.

Step 3: Layer Alignment and Setup

Once data is loaded, proper layer setup ensures accurate verification and output. This step in the CAM350 Gerber workflow catches issues that would otherwise reach production.

Aligning Layers

If layers appear offset from each other:

1. Select Edit → Layers → Align
2. Choose a reference point common to all layers (typically a board corner or tooling hole)
3. Apply alignment to bring all layers into registration

Setting the Origin

Establish a consistent datum for measurements and panelization:

1. Go to Edit → Change → Origin → Datum Coordinate
2. Click on your desired origin point (typically lower-left board corner)
3. All coordinates will now reference this point

Layer Ordering

Organize layers in a logical stackup order:

1. Select Edit → Layers → Reorder
2. Drag layers into proper sequence (Top → Inner → Bottom)
3. Delete any unused or empty layers

Standard PCB Layer Designations

Extension	Layer Type	Description
.GTL	Top Copper	Top signal layer
.GBL	Bottom Copper	Bottom signal layer
.GTS	Top Soldermask	Top solder resist
.GBS	Bottom Soldermask	Bottom solder resist
.GTO	Top Silkscreen	Top overlay/legend
.GBO	Bottom Silkscreen	Bottom overlay/legend
.GTP	Top Paste	Top stencil layer
.GBP	Bottom Paste	Bottom stencil layer
.GKO/.GML	Board Outline	Mechanical/keepout layer
.DRL	Drill File	NC drill data

Step 4: Running Design Rule Checks (DRC)

The DRC function in CAM350 Gerber processing identifies spacing violations, minimum feature sizes, and other rule violations before they become production problems.

Basic DRC Procedure

1. Navigate to Analysis → DRC
2. Configure check parameters based on your fab house capabilities:
   1. Minimum trace width
   1. Minimum spacing
   1. Minimum annular ring
   1. Minimum drill size
3. Select layers to check
4. Run the analysis

Key DRC Parameters to Verify

Check Type	Typical Minimum	What It Catches
Trace Width	4-6 mil	Narrow traces that may open
Trace Spacing	4-6 mil	Shorts between conductors
Annular Ring	4-5 mil	Breakout risk on pads
Drill to Copper	8-10 mil	Shorts to internal layers
Solder Mask Sliver	4 mil	Mask adhesion problems

Review each error in the results list. CAM350 highlights violations on the design, making it easy to locate and assess each issue.

Step 5: DFM Analysis for Manufacturing Verification

Beyond basic DRC, Design for Manufacturing analysis in Gerber CAM350 evaluates your design against real production capabilities.

Running DFM Streams

1. Select Analysis → Streams RC (or use the Streams toolbar)
2. Choose or create a stream file containing your checks
3. Include tests for:
   1. Acid traps (acute copper angles)
   1. Copper slivers (thin copper features)
   1. Soldermask slivers
   1. Thermal relief issues
   1. Solder bridge potential
4. Execute the stream and review results

DFM analysis catches issues that pass DRC but still cause production problems. Acid traps, for example, might meet spacing rules but trap etchant and cause copper defects.

Step 6: Netlist Comparison and Verification

Netlist compare is the most critical verification step in CAM350 Gerber processing. It confirms that your Gerber data matches the original design intent by checking electrical connectivity.

Netlist Compare Process

1. Import your reference netlist (IPC-D-356 format is preferred):
   1. File → Import → Netlist
   1. Select the IPC-D-356 file from your CAD export
2. Extract a netlist from your Gerber data:
   1. Utilities → Netlist Extract
   1. Accept default settings for basic extraction
3. Run the comparison:
   1. Analysis → Compare Netlists
   1. Select both the imported reference and extracted netlists
4. Review results for:
   1. Open circuits (broken connections)
   1. Short circuits (unintended connections)
   1. Missing nets
   1. Extra nets

Preparing Data for Accurate Netlist Extraction

For reliable netlist extraction from Gerber CAM350:

• Ensure all layers are properly aligned
• Verify drill data is correctly loaded and positioned
• For blind/buried vias, define layer sets correctly in Home → Panes → Layer Sets
• Convert drawn pads to flashes if needed: Tools → Draw to Flash

Step 7: Editing Gerber Data in CAM350

CAM350 allows direct modification of Gerber data—useful for fixing minor issues without returning to the source CAD system.

Common Editing Operations

Adding or Modifying Features:

• Select Edit → Add to place new flashes, lines, or polygons
• Use Edit → Move to reposition elements
• Apply Edit → Delete to remove unwanted features

Converting Draw to Flash:

• Utilities → Draw → Flash → Interactive converts drawn pads to proper flashes
• Essential for accurate netlist extraction and manufacturing

Adding Teardrops:

• Tools → Teardrops adds reinforcement at trace-to-pad junctions
• Improves reliability without changing CAD source

Clearing Silkscreen from Pads:

• Prevents silkscreen ink from contaminating solder joints
• Use Utilities → Silkscreen → Clear Pads

Creating Drill Data from Gerber (When Drill File Missing)

If a customer doesn’t provide drill files:

1. Select Utilities → Draw → Custom to create custom apertures
2. Use Utilities → Draw → Flash → Interactive to place hole positions
3. Switch to drill editing mode
4. Convert flashes to drill hits: Utilities → Gerber to Drill
5. Verify drill sizes and positions

Step 8: Panelization with CAM350

Production efficiency often requires combining multiple boards into panels. The CAM350 Gerber panelization workflow handles this efficiently.

Basic Panelization Steps

1. File → New to create a new project
2. File → Merge to bring in your first board
3. Place the board at the desired position
4. Repeat merge for additional boards or copies
5. Edit → Change → Explode → All to flatten merged data
6. Combine identical layers using Move To Layer function

Panel Design Considerations

Element	Purpose	CAM350 Tool
V-Score Lines	Depanelization	NC Editor
Mouse Bites	Tab routing	NC Editor / Panel Editor
Tooling Holes	Fixture alignment	Drill Editor
Fiducials	Pick-and-place reference	Manual placement
Rails	Handler clearance	Panel Editor

Step 9: Exporting Modified Gerber Files

After processing, export your data for fabrication:

Gerber Export

1. Select File → Export → Gerber Data
2. Configure export settings:
   1. Format: RS-274X (recommended)
   1. Units: Match your original or fab requirements
   1. Precision: Typically 2:4 inches or 3:3 metric
3. Set the export path
4. Rename files if needed to match fab naming conventions
5. Click OK to export

Drill Export

1. Select File → Export → Drill Data
2. Choose format settings (typically Leading 3,3 metric)
3. Important: Ensure each drill file has a unique name to prevent overwriting
4. Export and verify

Post-Export Verification

Always reload your exported files in a new CAM350 session to verify:

• All layers present and complete
• Drill data aligned correctly
• No data corruption during export

Troubleshooting Common CAM350 Gerber Problems

Problem	Cause	Solution
Layers misaligned	Format/unit mismatch	Re-import with correct settings
Drill offset from pads	Zero suppression mismatch	Check Leading/Trailing setting
Missing apertures	RS-274D without aperture file	Load aperture file or use RS-274X
Import fails completely	Corrupted or non-standard file	Try manual import with format override
Netlist shows opens	Layer alignment issue	Align layers and re-extract
Slow performance	Large file / heavy copper	Increase RAM, process layers individually

Useful CAM350 and Gerber Resources

Resource	URL	Description
DownStream Technologies	https://www.downstreamtech.com	Official CAM350 vendor
CAM350 Tech Tips	https://www.downstreamtech.com/cam350-tech-tips/	Official tutorials and guides
Free Viewer Download	https://www.downstreamtech.com/free-viewers/	View CAM350 data without license
Training Webinars	https://www.downstreamtech.com/webinars/	Free learning sessions
Siemens EDA Documentation	https://eda.sw.siemens.com	Valor CAM350 resources

Frequently Asked Questions

What Gerber format should I use with CAM350?

Use RS-274X (Extended Gerber) whenever possible. This format embeds aperture definitions within the file, eliminating the compatibility issues common with RS-274D. All modern PCB CAD tools support RS-274X export. The older RS-274D format requires a separate aperture file, and any mismatch between the Gerber and aperture files causes import failures. When working with CAM350 Gerber data from unknown sources, try Auto-detect apertures first.

How do I fix drill misalignment in CAM350?

Drill misalignment typically results from format mismatches between the drill file and Gerber data. First, check that units match (inches vs. millimeters). Then verify the coordinate format—if your Gerber uses 2:4 format, your drill file should match. Finally, confirm zero suppression settings (Leading vs. Trailing). Re-import the drill file with corrected settings, then overlay on copper to verify alignment. Use Edit → Layers → Align if minor adjustment is needed.

Can CAM350 convert Gerber files back to CAD format?

Yes, CAM350 includes Reverse Engineering capability in higher configurations. This feature converts non-intelligent Gerber data back into a structured format with defined traces, vias, padstacks, and nets. The process involves building parts, extracting netlists, and exporting to CAD formats like PADS ASCII or GenCAD. However, the result requires significant cleanup and should be considered a starting point rather than a finished design. It’s most useful for legacy designs where original CAD data is lost.

Why does netlist extraction show errors when my design is correct?

Netlist extraction problems in Gerber CAM350 usually stem from data preparation issues rather than actual design errors. Common causes include: drawn pads instead of flashes (run Draw to Flash conversion), misaligned layers (check alignment), missing or incorrect drill data (verify drill import settings), and undefined layer sets for blind/buried vias. Address these data issues before re-running extraction. Also ensure you’re using an IPC-D-356 netlist for comparison rather than a reference-designator-based netlist.

What’s the difference between DRC and DFM analysis in CAM350?

DRC (Design Rule Check) verifies basic geometric rules like minimum trace width, spacing, and annular ring. These are pass/fail checks against specific numeric values. DFM (Design for Manufacturing) analysis goes deeper, identifying features that might pass DRC but still cause production problems—acid traps, copper slivers, thermal relief issues, and potential solder bridges. Think of DRC as checking the rules and DFM as checking manufacturability. Both are essential steps in the CAM350 Gerber verification workflow.

Conclusion

Mastering CAM350 Gerber processing takes practice, but the payoff is substantial—fewer fabrication issues, faster turnaround, and more reliable products. The workflow I’ve outlined here covers the essential steps: proper import with format matching, layer alignment and setup, DRC and DFM verification, netlist comparison, editing when necessary, and clean export for production.

The most common problems I see come from format mismatches during import and skipped verification steps. Take the time to verify drill alignment, run DRC checks, and compare netlists before releasing files to manufacturing. These steps catch issues that would otherwise become expensive production problems.

Whether you’re a designer verifying output or a CAM engineer preparing production files, these Gerber CAM350 techniques will improve your results and streamline your workflow.