How to View Gerber Files with CAM350: Complete PCB Engineer’s Guide

If you’ve spent any time in PCB manufacturing or worked closely with fabrication houses, you’ve almost certainly encountered CAM350. This industry-standard CAM software has been the backbone of PCB pre-production workflows for decades, and for good reason. While basic Gerber viewers let you see your files, CAM350 takes things to an entirely different level—offering professional-grade viewing, editing, DFM analysis, and manufacturing preparation all in one package. This guide walks you through everything you need to know about using CAM350 to view Gerber files effectively.

What Is CAM350 and Why PCB Professionals Use It

CAM350, now part of the Siemens Valor product family, is a professional CAM (Computer-Aided Manufacturing) software designed specifically for the PCB industry. Unlike simple Gerber viewers that only display files, CAM350 provides a complete suite of tools to import, view, analyze, edit, and export design data for manufacturing. The software bridges the gap between PCB design and fabrication, ensuring designs translate into manufacturable products.

CAM350 Key Capabilities

Feature Category	Capabilities
Import Formats	Gerber (274D, 274X, Fire9000, Barco DPF), ODB++, IPC-2581, Excellon, Sieb & Meyer, DXF, GenCAD, HPGL
Export Formats	Gerber (274D, 274X), ODB++, IPC-2581, DXF, Excellon, Sieb & Meyer, HPGL, PADS ASCII, GenCAD
Viewing	Layer-by-layer display, 2D/3D visualization, stackup viewer, overlay modes
Analysis	DFM/DFA/DFT checks, netlist comparison, design analyzer, copper area calculation
Editing	Gerber editing, drill optimization, panelization, stencil design
Measurement	Point-to-point, object-to-object, distance, area calculations

What sets CAM350 apart from free viewers is its intelligence. The software doesn’t just display Gerber artwork—it understands the data contextually. CAM350 can identify nets, pads, traces, vias, and component footprints, enabling sophisticated analysis that simple viewers cannot perform.

CAM350 Configuration Tiers

CAM350 comes in various configurations to match different workflow needs:

Configuration	Primary Use	Key Features
CAM350-070	Gerber Viewing	Import, view, query, report, measure, 2D/3D visualization
CAM350-090	Entry-Level Analysis	Gerber export, data editing, intelligent import, basic DRC
CAM350-160	Advanced Analysis	NC editing, DXF interface, CrossProbing, panel design, automation
DFMStream-520	Full DFM	Complete DFM/DFA checks, design analyzer, rigid-flex analysis
CAM350-620	Production Prep	Advanced panel editor, NC editor, flying probe, reverse engineering

For most engineers focused on viewing and basic verification, the entry-level configurations provide more than adequate functionality.

Importing Gerber Files into CAM350

CAM350 offers two primary methods for loading Gerber files: AutoImport for streamlined loading and manual import for precise control.

Using AutoImport for Quick Loading

The AutoImport feature is the fastest way to load a complete Gerber package. CAM350 automatically identifies file types and assigns layers appropriately.

Step 1: Launch CAM350 and navigate to File → Import → AutoImport.

Step 2: In the AutoImport dialog, click “Choose Directory” and navigate to the folder containing your Gerber files.

Step 3: CAM350 scans the directory and identifies all recognized file types. Review the file list to ensure all expected files appear.

Step 4: Click “Finish” to complete the import. CAM350 loads all files and assigns them to appropriate layers based on file extensions and content analysis.

Importing Drill Files Separately

Drill files often require separate handling for correct interpretation. After loading Gerber layers:

Step 1: Go to File → Import → Drill Data.

Step 2: Click the browse button and navigate to your drill file (typically .drl, .exc, or .ncd extension).

Step 3: In the import options, select the correct format settings. For most modern files, choose “Leading” zero suppression and verify the coordinate format matches your CAD tool’s output.

Step 4: Press OK to import the drill data.

Manual Import for Problem Files

When AutoImport doesn’t recognize files correctly, manual import provides explicit control:

Import Type	Menu Path	When to Use
Gerber	File → Import → Gerber	Non-standard Gerber file extensions
NC Drill	File → Import → Drill Data	Excellon or Sieb & Meyer drill files
NC Mill	File → Import → Mill Data	Router and outline data
Aperture	File → Import → Aperture	RS-274D files needing aperture definitions
Netlist	File → Import → Netlist	IPC-D-356 or other netlist formats

Navigating and Viewing Gerber Data

Once files are loaded, CAM350 provides comprehensive tools for examining your design.

Layer Management

The layer panel displays all loaded files with color-coded indicators. Each layer can be controlled independently for visibility, color, and rendering mode.

Toggle Layer Visibility: Click the visibility checkbox next to any layer to show or hide it. Multiple layers can be displayed simultaneously to check alignment and registration.

Change Layer Colors: Right-click a layer and select “Change Color” to assign distinctive colors that help differentiate copper, mask, silkscreen, and drill layers.

Reorder Layers: Navigate to Edit → Layers → Reorder to arrange layers in the correct stackup sequence. Proper layer ordering is essential for accurate 3D visualization and analysis.

Zoom and Pan Controls

Action	Method
Pan	Click and drag with middle mouse button
Zoom In	Mouse wheel up, or View → Zoom → In
Zoom Out	Mouse wheel down, or View → Zoom → Out
Fit to Window	View → Zoom → Fit, or press Home key
Zoom to Selection	Draw rectangle while holding Shift
Previous View	View → Previous View

Overlay Modes for Layer Comparison

CAM350 excels at displaying multiple layers simultaneously. Use overlay modes to verify alignment between layers:

Standard Overlay: Upper layers draw on top of lower layers, showing the complete stackup view.

XOR Mode: Highlights differences between layers—identical features cancel out, leaving only unique content visible. Perfect for comparing design revisions.

Transparency Mode: Blends layers with adjustable opacity, allowing visualization of internal layers through external ones.

Measuring Distances and Dimensions

Accurate measurement is critical for manufacturing verification. CAM350 provides sophisticated measurement tools that go beyond basic point-to-point distance.

Using the Measurement Tool

Access measurement functions through Info → Measure in the menu:

Measurement Type	Description	Use Case
Point-to-Point	Distance between two clicked locations	General measurements
Object-to-Object	Shortest distance between two elements	Clearance verification
Object-to-Edge	Distance from element to board edge	Edge clearance checks
Center-to-Center	Distance between pad or via centers	Pitch verification

Step 1: Select the desired measurement type from Info → Measure.

Step 2: Click on the first point or object.

Step 3: Click on the second point or object.

Step 4: The measurement result displays in the status bar and information window.

Querying Element Properties

Beyond measurement, CAM350 can provide detailed information about any design element. Use Info → Query or simply press ‘Q’ while hovering over an element to see:

Properties displayed include D-code and aperture information, element type (pad, trace, polygon), layer assignment, X/Y coordinates, size and dimensions, net assignment (if netlist is loaded), and drill tool information (for holes).

Running DFM Analysis in CAM350

Design for Manufacturability analysis is where CAM350 truly differentiates itself from basic viewers. The DFM tools identify potential manufacturing problems before files go to production.

Basic DFM Checks

Even entry-level CAM350 configurations include essential DFM capabilities:

Check Type	What It Detects
Acid Traps	Acute angle copper features that trap etchant
Copper Slivers	Thin copper strips that may lift during processing
Soldermask Slivers	Thin mask areas prone to bridging or peeling
Annular Ring	Insufficient copper around drill holes
Starved Thermals	Thermal relief spokes too thin for current
Spacing Violations	Copper-to-copper clearance below minimum

Running Analysis Streams

CAM350’s Streams methodology organizes DFM checks into logical groups:

Step 1: Navigate to Analysis → DFM → Streams.

Step 2: Select a predefined stream or create a custom analysis sequence.

Step 3: Configure parameters for each check type based on your manufacturer’s capabilities.

Step 4: Execute the stream. CAM350 highlights violations directly on the design.

Step 5: Review results using the navigation tools to jump between error locations.

Design Analyzer for Fabrication Quoting

The Design Analyzer extracts key manufacturing parameters automatically:

Parameter	What It Measures
Board Dimensions	Overall size and shape
Layer Count	Number of copper layers
Minimum Trace Width	Smallest conductor width
Minimum Spacing	Smallest gap between conductors
Minimum Hole Size	Smallest drill diameter
Via Types	Through, blind, buried, laser via technologies
Copper Weight	Estimated copper density
Aspect Ratio	Board thickness to minimum hole ratio

This information helps fabricators provide accurate quotes and identifies features requiring advanced manufacturing capabilities.

Editing and Modifying Gerber Data

CAM350 is not just a viewer—it’s a full Gerber editor. Common editing tasks include correcting design errors before fabrication, adding or removing features, panelizing designs for production, and optimizing drill data.

Common Edit Operations

Operation	Menu Path	Use Case
Delete Element	Edit → Delete	Remove unwanted features
Move Element	Edit → Move	Reposition design elements
Copy Element	Edit → Copy	Duplicate features
Change D-Code	Edit → Change → D-Code	Modify aperture assignment
Add Pad	Insert → Pad	Insert new pad features
Add Trace	Insert → Trace	Draw new conductor paths

Layer Alignment

When Gerber files from different sources have misaligned origins:

Step 1: Navigate to Edit → Layers → Align.

Step 2: Select the reference layer (typically the most accurate).

Step 3: Click on a reference point in the reference layer.

Step 4: Select the layer to align.

Step 5: Click on the corresponding point in that layer.

Step 6: CAM350 calculates and applies the offset to align the layers.

Setting the Origin

For proper coordinate system alignment:

Navigate to Edit → Change → Origin → Datum Coordinate and click on the desired origin location (typically lower-left corner of the board outline).

Exporting Modified Gerber Files

After viewing, analyzing, or editing, export your data in appropriate formats.

Gerber Export

Step 1: Go to File → Export → Gerber Data.

Step 2: Select the export path and configure filenames for each layer.

Step 3: Choose the Gerber format (RS-274X recommended for modern workflows).

Step 4: Set coordinate format (typically 2,4 imperial or 3,3 metric).

Step 5: Click OK to generate the Gerber files.

Drill Data Export

Step 1: Navigate to File → Export → Drill Data.

Step 2: Select output format (Excellon is most common).

Step 3: Configure coordinate format to match your Gerber export settings.

Step 4: Assign tool tables if required by your manufacturer.

Step 5: Export the drill file.

CAM350 vs Free Gerber Viewers

Understanding when CAM350’s capabilities are necessary versus when free viewers suffice helps make informed decisions.

Feature	CAM350	ViewMate (Free)	Gerbv (Free)
View Gerber	Yes	Yes	Yes
View Drill Files	Yes	Yes	Yes
Measurement	Advanced	Basic	Basic
DFM Analysis	Comprehensive	No	No
Gerber Editing	Full	Limited	Limited
Panelization	Yes	No	No
3D Visualization	Yes	No	No
Netlist Comparison	Yes	No	No
Reverse Engineering	Yes	No	No
Price	Commercial	Free	Free

For simple verification before ordering prototypes, free viewers often suffice. CAM350 becomes essential when you need to edit files, run DFM checks, prepare production panels, or reverse engineer designs from Gerber back to intelligent CAD data.

Useful Resources for CAM350 Users

Official Resources

Resource	URL	Description
Siemens CAM350	eda.sw.siemens.com/pcb/valor/cam350	Official product page
DownStream Technologies	downstreamtech.com/products/cam350	Detailed feature documentation
CAMvu Free Viewer	downstreamtech.com/products/viewers	Free viewer for CAM350 databases
Video Tutorials	Siemens support portal	Training videos and webinars

Alternative CAM Software

Software	Developer	Notes
Genesis 2000	Orbotech/KLA	Industry standard for fabricators
InCAM	Ucamco	Gerber format creator’s own CAM tool
FAB 3000	Numerical Innovations	Cost-effective alternative
CircuitCAM	LPKF	Focused on prototyping

Community and Support

Resource	URL
Siemens Support Center	support.sw.siemens.com
PCB Design Forums	Various online communities
Training Programs	Contact Siemens or resellers

Frequently Asked Questions

Is CAM350 free to use?

No, CAM350 is commercial software with custom pricing based on configuration and license type. However, Siemens offers free trials for evaluation, and the CAMvu viewer is available at no cost for viewing CAM350 database files. For organizations doing occasional Gerber verification without editing or DFM needs, free viewers like ViewMate or Gerbv may be sufficient. CAM350’s value becomes apparent when you need advanced analysis, editing, or manufacturing preparation capabilities that free tools cannot provide.

How do I fix drill holes that appear offset from pads in CAM350?

Drill offset problems typically stem from coordinate format mismatches between Gerber and drill exports. In CAM350, first verify the coordinate format settings used during import match your CAD tool’s export settings. Navigate to Edit → Layers → Align to manually align drill layers with copper. Select a reference pad on the copper layer, then click the corresponding drill hole. CAM350 calculates the offset and aligns the layers. If systematic offset exists across all holes, check whether leading/trailing zero suppression settings match between file types. Most modern CAD tools export in 2,4 format (imperial) or 3,3 format (metric)—ensure consistency.

Can CAM350 convert Gerber files back to editable CAD formats?

Yes, CAM350’s Reverse Engineering feature converts non-intelligent Gerber data back into an intelligent format with nets, pads, traces, vias, and component footprints identified. The process analyzes the Gerber artwork, identifies patterns that represent standard PCB features, and reconstructs connectivity information. While not perfect—some design intent may be lost in the original Gerber export—reverse engineering enables significant recovery of design intelligence. The resulting data can be exported to formats compatible with PCB CAD tools like PADS, Allegro, or others, enabling design modifications that would be impossible to make accurately in raw Gerber.

What’s the difference between CAM350 and DFMStream?

CAM350 and DFMStream are related products from the same family, both now under Siemens Valor. CAM350 focuses on general CAM operations including viewing, editing, and manufacturing preparation. DFMStream emphasizes comprehensive DFM/DFA/DFT analysis with advanced checking capabilities. In practice, they share significant functionality, and higher-tier CAM350 configurations include DFMStream analysis features. For engineers primarily concerned with design verification before manufacturing, the DFMStream-focused configurations provide the most relevant analysis tools. For fabricators preparing data for production, CAM350’s editing, panelization, and NC editing features become more important.

How does CAM350’s 3D visualization help with Gerber viewing?

CAM350’s 3D visualization renders your PCB stackup as a three-dimensional model, showing how the finished board will look. This helps identify issues that are difficult to spot in 2D layer views: layer registration problems become obvious when copper doesn’t align through the stackup, drill-to-copper relationships are easier to verify, and overall board construction becomes intuitive to review. The 3D view is particularly valuable for complex multilayer designs where understanding the relationship between blind/buried vias and internal layers matters. You can rotate, zoom, and section the 3D model to examine any aspect of the design from any angle.

Best Practices for Using CAM350

Years of working with CAM350 in production environments have taught me several habits that consistently improve results.

Always verify import completeness. After AutoImport, check that all expected layers loaded correctly. Missing files are the most common source of manufacturing problems, and catching them during CAM review prevents costly delays.

Set the origin consistently. Before any analysis or editing, establish the datum coordinate at a logical location (typically lower-left board corner). Consistent origins make layer alignment predictable and measurement results meaningful.

Use layer templates. If you regularly work with similar designs, create layer color and ordering templates. Consistent visual presentation helps your brain spot anomalies faster.

Run DFM before every production release. Even if your design passed DRC in your CAD tool, CAM350’s DFM analysis catches issues specific to manufacturing processes. A few minutes of DFM analysis can prevent days of production delays.

Save projects, not just exports. CAM350’s native .CAM file format preserves your complete session including layer assignments, colors, and analysis results. Export Gerber only when you need to send files elsewhere.

Document changes meticulously. When editing Gerber files in CAM350, maintain records of every modification. This audit trail proves invaluable when troubleshooting manufacturing issues later.

CAM350 represents the professional standard for PCB CAM software, and its capabilities extend far beyond simple Gerber viewing. Whether you’re a designer verifying files before ordering prototypes or a CAM engineer preparing production data, mastering CAM350 pays dividends in reduced errors, faster turnaround, and higher manufacturing yields.