How to Generate Gerber Files from Zuken CADSTAR: Complete PCB Manufacturing Guide

Zuken CADSTAR has earned its reputation as a reliable, mid-range PCB design tool that punches above its weight class. It’s particularly popular among smaller design teams and companies that need professional-grade capabilities without enterprise-level complexity. But even the cleanest schematic and most elegant layout mean nothing if you can’t get proper manufacturing files to your fabricator.

I’ve used CADSTAR on dozens of projects over the years, from simple two-layer boards to complex eight-layer designs with controlled impedance requirements. What I appreciate most about CADSTAR’s approach to Gerber generation is its straightforward workflow. Unlike some tools that bury manufacturing output under layers of menus, CADSTAR makes the process reasonably intuitive once you understand the basics.

This guide provides a complete walkthrough of generating Gerber files from Zuken CADSTAR, from pre-output verification through final file validation. Whether you’re new to CADSTAR or looking to refine your existing workflow, you’ll find practical guidance that translates directly to successful fabrication runs.

Understanding CADSTAR’s Manufacturing Output System

Before jumping into procedures, understanding how CADSTAR handles manufacturing output helps you make better configuration decisions.

CADSTAR’s Plot and Manufacturing Architecture

CADSTAR uses a plot-based output system that’s conceptually similar to printing documents. You define “plots” that specify what design data appears on each output, configure format settings, and generate the files. This approach is intuitive for most users since it mirrors familiar printing workflows.

The manufacturing output system in CADSTAR handles Gerber file generation (RS-274X format), NC drill output (Excellon format), pick and place data for assembly, bill of materials generation, and various report outputs.

Gerber Format Support

CADSTAR supports the industry-standard Gerber RS-274X format, also known as Extended Gerber. This format embeds aperture definitions directly in each file, eliminating the coordination problems that plagued older RS-274D outputs requiring separate aperture files.

For most PCB fabricators worldwide, RS-274X provides optimal compatibility. Some newer fabricators accept Gerber X2 or ODB++, but RS-274X remains the safe choice when you’re unsure of your manufacturer’s capabilities.

Layer Mapping Concepts

CADSTAR organizes design data across multiple layer types including electrical layers for copper routing, documentation layers for silkscreen and notes, construction layers for board outlines and dimensions, and manufacturing layers for mask and paste definitions.

When generating Gerber output, you map these design layers to physical manufacturing layers. Understanding this mapping is key to getting complete, correct output files.

Preparing Your CADSTAR Design for Gerber Output

Proper preparation prevents frustrating rejection cycles with your fabricator. These verification steps take minutes but save considerable time and money.

Running Design Rule Checks

Before generating any manufacturing files, run a comprehensive DRC in CADSTAR. Access Design Rule Check through the Tools menu or use the DRC toolbar button.

Critical checks to run and resolve include spacing violations between copper features, minimum track width violations, drill-to-copper clearance issues, unconnected pins and incomplete nets, and silk screen over pad violations.

Address all errors before proceeding. For warnings, evaluate each against your specific fabricator’s capabilities. What CADSTAR considers acceptable might exceed your manufacturer’s process limits.

Verifying Layer Stackup

Your layer stackup configuration directly affects Gerber output. Access stackup settings through Settings and then Design Technology.

Verify that all layers are present and correctly ordered, layer types are properly assigned (signal, plane, etc.), copper weights match your fabrication specification, and dielectric thicknesses are correct for any impedance-controlled designs.

Checking Component and Pad Definitions

Review your component library definitions for manufacturing compatibility. Key parameters to verify include minimum drill sizes meeting fabricator requirements (typically 0.2mm minimum), annular ring dimensions satisfying manufacturing tolerances, thermal relief patterns properly defined for plane connections, and solder mask and paste mask expansions correctly configured.

Access component definitions through the Library Manager. Pay special attention to any custom components you’ve created.

Board Outline Verification

Confirm your board outline is properly defined on the appropriate layer. The outline should be a single, closed shape without gaps. Any internal cutouts should also be closed shapes. Verify dimensions match your intended board size.

Step-by-Step Guide to Generate Gerber Files from CADSTAR

Now let’s walk through the complete Gerber generation process in Zuken CADSTAR.

Step 1: Accessing the Manufacturing Output Manager

Open your design in CADSTAR PCB. Navigate to Output and then Manufacturing Plots, or access through File and then Plot Outputs depending on your CADSTAR version.

This opens the Plot Output Configuration dialog, your command center for all Gerber generation settings.

Step 2: Understanding the Plot Output Interface

The Plot Output interface displays available plot definitions and their settings. For a new design, you may see default plot templates or an empty configuration requiring setup from scratch.

The interface typically shows a list of defined plots on the left, configuration options in the center, and preview or status information on the right.

Step 3: Creating Plot Definitions for Each Layer

Each manufacturing layer needs its own plot definition. Create definitions for all required outputs.

For a standard 4-layer board, you’ll need Top Copper (Component Side), Inner Layer 1 (typically ground), Inner Layer 2 (typically power), Bottom Copper (Solder Side), Top Solder Mask, Bottom Solder Mask, Top Silkscreen (Legend), Bottom Silkscreen (Legend), Top Paste Mask (for SMT stencil), Bottom Paste Mask, and Board Outline.

Click Add or New Plot to create each definition. Give each plot a clear, descriptive name that identifies the layer.

Step 4: Configuring Gerber Format Settings

For each plot definition, configure the output format parameters. These settings must be consistent across all outputs.

Select Gerber RS-274X as the output format. Set units to match your design (typically millimeters for metric designs, inches for imperial). Configure the coordinate format, with 3:4 format providing 0.0001mm resolution for metric and 2:5 format providing 0.00001 inch resolution for imperial. Set zero suppression to Leading, which is standard for most fabricators. Choose Absolute coordinate mode. Configure the output file path and name.

Step 5: Mapping Design Layers to Outputs

For each plot definition, specify which design layers contribute to that output. This mapping is critical for correct manufacturing files.

For copper layer plots, select the corresponding electrical layer. Include associated via layers and pad definitions. Include any copper fill or pour layers.

For solder mask plots, select the solder mask layer for the corresponding board side. CADSTAR typically auto-generates mask openings from pad definitions. Verify mask expansion settings match your fabricator’s requirements.

For silkscreen plots, select the silk layer and/or legend layer. Include component outlines and reference designators. Exclude any layers that shouldn’t appear on silk.

For paste mask plots, select the paste layer for SMT component pads. Verify paste reduction settings if your fabricator recommends specific values.

For board outline, select the construction or board layer containing your outline. Include only outline geometry, not internal features unless required.

Step 6: Configuring Aperture Settings

CADSTAR can generate apertures automatically or use predefined aperture tables. For most applications, automatic aperture generation works well.

In the plot settings, select automatic aperture mode. CADSTAR analyzes your design features and creates appropriate apertures during output generation.

If your fabricator provides a specific aperture table, you can load it and configure CADSTAR to map features to those predefined apertures.

Step 7: Setting Output Filenames

Consistent, descriptive filenames help fabricators identify your layers quickly. Configure meaningful names for each plot.

Layer Type	Recommended Filename	Standard Extension
Top Copper	BoardName_Top	.GTL
Bottom Copper	BoardName_Bottom	.GBL
Inner Layer 1	BoardName_L2	.G2
Inner Layer 2	BoardName_L3	.G3
Top Solder Mask	BoardName_TSM	.GTS
Bottom Solder Mask	BoardName_BSM	.GBS
Top Silkscreen	BoardName_TSilk	.GTO
Bottom Silkscreen	BoardName_BSilk	.GBO
Top Paste	BoardName_TPaste	.GTP
Bottom Paste	BoardName_BPaste	.GBP
Board Outline	BoardName_Outline	.GKO or .GM1
NC Drill PTH	BoardName_PTH	.DRL or .XLN
NC Drill NPTH	BoardName_NPTH	.DRL or .XLN

Create a dedicated manufacturing folder in your project directory to keep output files organized.

Step 8: Generating the Gerber Files

With all plot definitions configured, generate your output files. Select the plots you want to generate. You can select all plots for batch generation or select individual plots as needed.

Click Generate, Plot, or OK to create the output files. CADSTAR processes each definition and writes Gerber files to your specified directory.

Monitor any messages or warnings during generation. Common informational messages relate to aperture creation. Warnings may indicate potential issues requiring attention.

Step 9: Generating NC Drill Output

Drill file generation typically uses the same Plot Output system or a dedicated NC Drill output function.

Access drill output configuration and set parameters including units matching your Gerber outputs, coordinate format consistent with Gerber settings, tool table format (usually embedded in file header), and zero suppression matching Gerber configuration.

Configure separate drill outputs for plated through-holes (PTH) and non-plated holes (NPTH). This separation is important because these hole types require different manufacturing processes.

Generate the drill files and verify the tool table lists all drill sizes correctly.

Advanced CADSTAR Gerber Output Techniques

Once you’ve mastered basic output generation, these techniques improve efficiency and handle special requirements.

Saving Output Configurations as Templates

CADSTAR allows saving your plot configurations for reuse. After configuring all plot definitions with correct layer mappings, format settings, and naming conventions, save the configuration.

Look for Save Plot Setup or Export Configuration options. Give the template a meaningful name like “4Layer_Standard” or “6Layer_Impedance.”

For future designs with similar layer structures, load this template as a starting point. You’ll only need to verify layer mappings and update output paths rather than configuring everything from scratch.

Batch Output Generation

For efficient production workflows, use CADSTAR’s batch generation capabilities. Configure all required plots in a single session. Select all plots and generate in one operation. This ensures consistency across all output files and reduces the chance of missing files.

Variant and Assembly Option Handling

If your design includes variants or different assembly configurations, CADSTAR can generate variant-specific outputs. Configure your variants in the design. Set up plot definitions that respect variant settings. Generate separate output packages for each variant with clear folder or naming distinctions.

Panelization Output

For production runs requiring panelized boards, you have options. You can create the panel within CADSTAR using panel design features and output the complete panel as a single Gerber set. Alternatively, you can provide single-board Gerbers and let your fabricator handle panelization.

For prototypes and small quantities, fabricator panelization is typically simpler. For production volumes with specific panel requirements, creating the panel in CADSTAR gives you complete control.

Verifying CADSTAR Gerber Files Before Submission

Never submit manufacturing files without independent verification. This critical step catches errors invisible within the design tool.

Using CADSTAR’s Built-in Preview

CADSTAR includes preview capabilities for generated outputs. After generation, use the plot preview function to review each output layer, check feature completeness, and look for obvious errors.

While useful, the built-in preview doesn’t catch all issues since it uses the same interpretation as the output generator.

External Gerber Viewer Verification

Load your complete output package in an independent Gerber viewer. This catches CADSTAR-specific output issues and shows exactly what your fabricator will receive.

Recommended free verification tools include GerbView from KiCad (cross-platform, handles Gerber and drill), ViewMate from Pentalogix (Windows-based with measurement tools), Ucamco Reference Gerber Viewer (free online tool from format maintainers), and ZofzPCB (provides 3D visualization of layer stackups).

Systematic Verification Checklist

During verification, systematically check layer registration by overlaying copper layers to confirm consistent alignment. Verify drill-to-pad alignment to ensure every drill hit centers on its pad. Check solder mask clearances for adequate opening around all pads. Confirm the board outline is complete and correctly defines boundaries. Verify silkscreen doesn’t overlap pad areas. For plane layers, confirm clearances and thermal reliefs appear correctly. Review the drill tool table for any unexpected sizes.

Complete Manufacturing Package Checklist

Before sending files to your fabricator, verify your package includes all required elements.

Category	Files Required	Notes
Copper Gerbers	One per copper layer	Signal and plane layers
Solder Mask	Top and bottom	Verify polarity with fab
Silkscreen	Top (bottom optional)	Check pad clearance
Paste Mask	Top and bottom	For SMT stencil fabrication
NC Drill	PTH and NPTH separate	Include tool table
Board Outline	One file	Include internal cutouts
Fabrication Spec	README or spec document	Stackup, finish, requirements
Assembly Data	Pick-and-place, BOM	If ordering assembly

Troubleshooting Common CADSTAR Output Issues

Even experienced users encounter output problems occasionally. Here are solutions to common issues.

Missing Features in Output

When expected features don’t appear in Gerber files, check that correct layers are selected in the plot definition. Verify all required layer types are included. Look for layer visibility settings that might affect output. Confirm features exist on expected layers in your design.

Aperture Problems

If pads appear incorrectly shaped or sized, verify automatic aperture generation is enabled. Check for complex shapes that may not convert correctly. Review any custom aperture mappings. Consider simplifying very complex pad geometries.

Drill and Gerber Misalignment

When drill holes don’t center on pads in the viewer, ensure identical origin settings for all outputs. Verify units match between Gerber and drill configurations. Check coordinate format consistency. Look for any offset settings applied differently between outputs.

Solder Mask Issues

If mask openings appear wrong, review pad definition mask expansion settings. Check global mask rules in design settings. Verify mask polarity matches fabricator expectations (positive typically shows openings).

Large or Problematic File Sizes

For unexpectedly large output files, check copper pour complexity settings. Verify coordinate precision isn’t excessive. Look for very complex polygon shapes. Consider arc interpolation settings for curved features.

Best Practices for CADSTAR Manufacturing Output

These practices, developed through production experience, improve reliability and reduce manufacturing issues.

Establish Standard Configurations

Create standard output configurations for your common board types. Document your standard settings and naming conventions. Train team members on established workflows. Review and update standards when requirements change.

Version Control

Implement clear version tracking for manufacturing outputs. Include version identifiers in folder names. Maintain revision logs documenting changes. Archive previous output versions for reference.

Fabricator Communication

Build relationships with your fabricators. Obtain their preferred format specifications. Ask about any special requirements. Request feedback on output quality. Establish direct contacts for technical questions.

Useful Resources for CADSTAR Users

These resources provide additional support for CADSTAR manufacturing output.

For official documentation, Zuken provides CADSTAR documentation through their support portal at zuken.com/support. The CADSTAR User Manual covers plot output in detail. CADSTAR Online Help includes context-sensitive guidance on output functions.

For Gerber format specifications, the official Gerber format specification is maintained by Ucamco at ucamco.com/gerber, covering RS-274X format comprehensively.

For verification tools, ViewMate is available at pentalogix.com for free Gerber viewing. GerbView is part of the KiCad suite at kicad.org. Ucamco’s Reference Gerber Viewer is available at gerber-viewer.ucamco.com.

For community and peer support, the CADSTAR User Forum is accessible through Zuken’s website. EDAboard.com hosts CADSTAR-related discussions. LinkedIn has CADSTAR user groups for professional networking.

For training resources, Zuken offers official CADSTAR training programs. Regional distributors often provide training courses. YouTube contains various CADSTAR tutorial videos.

Frequently Asked Questions

What Gerber format should I select in CADSTAR for best compatibility?

Select Gerber RS-274X (Extended Gerber) for maximum compatibility with PCB fabricators worldwide. This format embeds aperture definitions directly in each file, eliminating the synchronization problems that occurred with older RS-274D format requiring separate aperture files. RS-274X is universally supported by modern fabrication equipment and CAM software. Always confirm specific format preferences with your manufacturer if you’re unsure.

How do I generate separate drill files for plated and non-plated holes?

In CADSTAR’s drill output configuration, create two separate drill output definitions. Configure the first to include only plated through-holes (PTH) by filtering on hole type. Configure the second for non-plated holes (NPTH) only. Name the files descriptively, such as “BoardName_PTH.drl” and “BoardName_NPTH.drl,” so fabricators can easily identify each type. This separation is critical because plated and non-plated holes require different manufacturing processes.

Can I save my plot configurations for reuse on other designs?

Yes, CADSTAR allows saving plot configurations as templates or setup files. After configuring all your plot definitions with layer mappings, format parameters, and naming conventions, export or save the configuration. For future designs with similar layer structures, import this template as a starting point. You’ll need to verify that layer names match and update output paths, but format settings and general configuration carry over, significantly reducing setup time.

Why are features missing from my generated Gerber files?

Missing features typically result from incomplete layer selection in your plot definitions. CADSTAR requires explicit specification of which layers to include in each output. Review your plot definition and verify all relevant layers are selected. Common oversights include missing via definitions on copper layers, incomplete silk layer selection, or copper pours on separate layers not included in the output. Also verify the features actually exist on the layers you expect in your design.

What additional files should I provide beyond Gerbers and drill files?

Include a fabrication specification document detailing board thickness, layer stackup, copper weights, surface finish (HASL, ENIG, OSP, etc.), solder mask color, silkscreen color, and any special requirements. Provide a layer stackup diagram showing layer order and materials. For impedance-controlled designs, include target impedance values with tolerances. If ordering assembly services, add pick-and-place centroid data (which CADSTAR can generate) and a complete bill of materials with manufacturer part numbers. A readme file summarizing package contents helps fabricators navigate your submission.

Conclusion

Generating Gerber files from Zuken CADSTAR follows a logical workflow that becomes second nature with practice. The plot-based output system is intuitive once you understand the layer mapping concepts, and the tool provides the flexibility needed to meet various fabricator requirements.

Success starts with thorough design verification before output generation. Configure each plot definition carefully, ensuring correct layer mappings and consistent format parameters across all outputs. Use descriptive naming conventions and organize your output files logically.

Always verify your outputs in an external Gerber viewer before submission. This independent check catches issues that might be invisible within CADSTAR and shows exactly what your fabricator will receive.

Build template configurations from successful outputs. CADSTAR’s ability to save and reload plot setups makes this practical, and the investment in creating good templates streamlines every future project.

CADSTAR may not have the brand recognition of some enterprise tools, but it delivers professional results when configured correctly. Master the output process, and you’ll consistently deliver fabrication packages that translate your designs into physical boards without issues.

When problems occur, approach troubleshooting systematically. Check layer selections, verify format parameters, and compare against outputs from previous successful projects. The CADSTAR user community and Zuken support resources provide help for unusual situations.

Your careful design work deserves manufacturing files that accurately represent it. Take the time to understand and configure CADSTAR’s output system properly, and you’ll build a reputation for clean, professional fabrication submissions.