Inquire: Call 0086-755-23203480, or reach out via the form below/your sales contact to discuss our design, manufacturing, and assembly capabilities.
Quote: Email your PCB files to Sales@pcbsync.com (Preferred for large files) or submit online. We will contact you promptly. Please ensure your email is correct.
Notes: For PCB fabrication, we require PCB design file in Gerber RS-274X format (most preferred), *.PCB/DDB (Protel, inform your program version) format or *.BRD (Eagle) format. For PCB assembly, we require PCB design file in above mentioned format, drilling file and BOM. Click to download BOM template To avoid file missing, please include all files into one folder and compress it into .zip or .rar format.
How to Export IPC-2581 Files from Cadence Allegro: Complete Guide
Cadence Allegro PCB Editor provides robust IPC-2581 export capabilities that allow designers to generate comprehensive manufacturing data in a single XML file. The export functionality supports multiple IPC-2581 versions and functional modes, giving you precise control over what data goes to your fabricator, assembler, or test house.
After years of sending separate Gerber, drill, and BOM files to manufacturers, the transition to IPC-2581 export from Allegro has noticeably reduced the back-and-forth communication about missing files or unclear layer definitions. This guide walks through the complete process of exporting IPC-2581 files from Cadence Allegro, including version selection, functional mode configuration, layer mapping, and verification procedures.
Cadence is a founding member of the IPC-2581 Consortium and has integrated comprehensive export capabilities directly into Allegro PCB Editor. The export function generates all required manufacturing and assembly data in a single XML-based file that can replace traditional Gerber file packages.
Data Included in IPC-2581 Export
Data Category
Description
Artwork layers
All copper and non-copper layer images
Drill data
Hole sizes, locations, and types
Layer stackup
Physical layer order with materials
Netlist
Complete electrical connectivity
Test pad information
Locations for bare board testing
Bill of Materials
Component references and values
Component placement
X/Y coordinates with rotation
Design variants
Multiple assembly configurations
The IPC-2581 export from Allegro allows you to suppress specific information depending on who receives the file. This protects intellectual property while still providing complete data for manufacturing.
Supported IPC-2581 Versions in Allegro
Version
Release Year
Key Features
IPC-2581 (Version 1)
2004
Original specification
IPC-2581A
2012
Enhanced fabrication data
IPC-2581B
2013
Back drilling, improved drill types
IPC-2581C
2020
Flex stackup, bidirectional DFX
Allegro supports all four versions, allowing you to match your manufacturer’s import capabilities.
Accessing the IPC-2581 Export Dialog
The IPC-2581 export function is located in the File menu under Export options.
Opening the Export Form
Open your completed PCB design in Allegro PCB Editor. Navigate to File → Export → IPC2581 to launch the IPC2581 Export form.
Menu Location
Allegro Version
File → Export → IPC2581
Standard path
Export → IPC 2581
Alternative access
The export dialog presents all configuration options in a single interface.
Configuring IPC-2581 Export Settings
The IPC2581 Export form contains several sections that control the output file content and format.
Basic Export Options
Setting
Description
Options
Output file name
Name for the .xml or .cvg file
User defined
Destination
Output folder location
Browse to select
IPC-2581 Version
Standard revision to use
1, A, B, or C
Output units
Measurement system
Millimeter, Micron, Inch
Version Selection Guidelines
Version
Recommended Use
Version 1
Legacy systems only
IPC-2581A
Basic fabrication data
IPC-2581B
Fabrication plus assembly with back drilling
IPC-2581C
Full manufacturing with flex and DFX
Version B is the most widely supported option for current manufacturing workflows. Select Version C only if your manufacturer explicitly supports the latest specification features like bidirectional DFX exchange.
Unit Selection Considerations
Unit
Precision
Use Case
Millimeter
0.001 mm
Standard PCB designs
Micron
0.001 µm
Fine-pitch and HDI
Inch
0.0001 inch
US-based manufacturers
Match the unit selection to your manufacturer’s preference or your design’s primary unit system to avoid conversion issues.
Understanding Functional Modes
The Functional Mode setting in Allegro’s IPC-2581 export controls what data gets included in the output file. This is critical for protecting intellectual property while providing appropriate data to each partner in your supply chain.
Available Functional Modes
Mode
Data Included
Target Recipient
FULL
Complete design data
Internal use, trusted partners
FAB
Fabrication only
PCB fabricators
ASSEMBLY
Assembly and placement
Assembly houses
TEST
Test point and netlist
Test service providers
USERDEF
Custom selection
Specific requirements
Functional Mode Selection
Scenario
Recommended Mode
Turnkey manufacturer
FULL or ASSEMBLY
Bare board fabricator
FAB
Assembly-only service
ASSEMBLY
Test house
TEST
SI/PI analysis tools
FULL or USERDEF
The USERDEF mode provides maximum flexibility by allowing you to check specific data categories for inclusion. This is particularly useful when exporting for analysis tools like Ansys SIwave that require specific data elements.
USERDEF Mode Configuration
When selecting USERDEF mode, you can individually enable or disable:
Data Element
Include for FAB
Include for Assembly
Copper artwork
Yes
Optional
Solder mask
Yes
Yes
Silkscreen
Yes
Yes
Drill data
Yes
Optional
Component data
No
Yes
BOM
No
Yes
Netlist
Optional
Yes
Stackup
Yes
Optional
Ensure all checkboxes are selected for USERDEF mode when maximum data transfer is required.
Layer Mapping Configuration
The Layer Mapping Editor in Allegro allows you to specify how design layers map to IPC-2581 layer types. Proper layer mapping ensures manufacturers correctly interpret your layer stack.
Accessing Layer Mapping Editor
Click Layer Mapping Edit in the IPC2581 Export form to open the layer mapping table.
Layer Type Assignments
Design Layer
IPC-2581 Layer Type
Description
Top/Bottom copper
OUTER
External signal layers
Inner signal
INNER
Internal signal layers
Plane layers
PLANE
Power and ground planes
Solder mask
SOLDERMASK
Mask opening definitions
Paste mask
SOLDERPASTE
Stencil apertures
Silkscreen
SILKSCREEN
Component markings
Assembly
DOCUMENTATION
Assembly drawings
Fab drawing
DOCUMENTATION
Fabrication notes
Configuring Layer Mapping
Step
Action
1
Open Layer Mapping Edit
2
Select ASSEMBLY, FAB, and SILKSCREENTOP as Documentation Layers
3
Select SOLDERMASKBOTTOM and SOLDERMASKTOP as SolderMask layers
4
Select PASTEMASKTOP and PASTEMASKBOTTOM as SolderPaste layers
5
Click OK to save settings
Incorrect layer mapping is a common source of manufacturing errors. Verify that all layers are assigned to appropriate IPC-2581 layer types before export.
Film Creation Options
The Film Creation button opens the Artwork Control Form, allowing you to generate or update film records before IPC-2581 export.
Artwork Control Form Settings
Option
Description
Available films
List of defined artwork layers
Select All
Include all films in export
Film parameters
Individual film settings
Film Selection Guidelines
Export Purpose
Films to Include
Full manufacturing
All layers
Fabrication only
Copper, mask, silkscreen, drill
Assembly only
Silkscreen, paste, placement
Click Select All to include all defined films, or individually select specific layers for partial exports.
Read more How to convert PCB Files in different Design software:
Several additional settings control the output file format and content.
Text and Compression Settings
Option
Description
Recommendation
Vector Text
Export text as line segments
Enable for universal compatibility
Compress Output File
Generate ZIP archive
Enable to reduce file size
Vector Text Benefits
Setting
Result
Enabled
Text rendered as geometry
Disabled
Text as font references
Enable Vector Text to ensure text displays correctly regardless of font availability in the receiving system.
Export Property Tab
The Export Property tab allows you to include additional component and net properties in the IPC-2581 file.
Property Type
Examples
Component
Manufacturer, Part Number, Value
Net
Impedance, Net Class, Critical
Select properties that your manufacturer needs for procurement or process control.
Step-by-Step Export Process
Follow this complete workflow to export IPC-2581 files from Cadence Allegro.
Export Workflow
Step
Action
Details
1
Open design
Load .brd file in Allegro PCB Editor
2
Access export
File → Export → IPC2581
3
Set file name
Enter output filename and destination
4
Select version
Choose IPC-2581B for most cases
5
Choose units
Match manufacturer preference
6
Set functional mode
Select FULL, ASSEMBLY, or USERDEF
7
Configure layer mapping
Click Layer Mapping Edit
8
Set film options
Click Film Creation if needed
9
Enable compression
Check Compress Output File
10
Enable vector text
Check Vector Text
11
Export
Click Export button
Post-Export Verification
Check
Method
File generated
Verify .xml or .zip file created
Export log
Review for errors or warnings
File size
Confirm reasonable size
Verifying IPC-2581 Output
Always verify exported IPC-2581 files before sending to manufacturing.
Free IPC-2581 Viewers
Viewer
Source
Features
Vu2581
DownStream Technologies
Measurements, layer visibility
DFM Now!
Numerical Innovations
DFM checks, markup
ZofzPCB
zofzpcb.com
3D visualization
PCB-Investigator
easylogix
Process integration
Verification Checklist
Item
What to Verify
Layer count
Matches design stackup
Board outline
Correct dimensions
Drill sizes
All holes present
Net names
Connectivity intact
Component count
All parts included
Placement data
Correct positions
BOM
Complete component list
Export Log Review
Allegro generates an export log showing general board information and any errors. Review this log before sending files to manufacturing.
Log Entry
Meaning
Export successful
Clean export
Warning
Non-critical issue
Error
Problem requiring attention
Troubleshooting Common Issues
Several issues can arise during IPC-2581 export from Allegro.
Export Errors
Issue
Cause
Solution
Export fails
Invalid layer mapping
Verify all layers mapped
Missing stackup
Stackup not defined
Configure layer stack manager
Missing drill data
No drill files generated
Run NC drill generation first
File too large
Uncompressed output
Enable compression option
Import Errors at Manufacturer
Error
Cause
Solution
Missing layers
Layer type not assigned
Check layer mapping editor
No component data
Wrong functional mode
Use ASSEMBLY or FULL mode
Invalid stackup
Version incompatibility
Try different IPC-2581 version
Functional Mode Errors
Error Message
Solution
Missing Stackup
Use FULL or USERDEF mode with Stackup enabled
No assembly data
Switch to ASSEMBLY or FULL mode
Incomplete BOM
Enable BOM in USERDEF mode
Comparing IPC-2581 with Other Formats
Understanding format differences helps you choose the right export for each situation.
Format Comparison
Aspect
Gerber + Files
ODB++
IPC-2581
File count
15-30+
1 archive
1 XML file
Stackup
Separate doc
Embedded
Embedded
Netlist
Separate IPC-356
Embedded
Embedded
BOM
Separate file
Embedded
Embedded
Governance
Ucamco
Siemens
IPC (open)
Allegro export time
Multiple steps
Single export
Single export
When to Use Each Format
Scenario
Recommended Format
Legacy manufacturer
Gerber
Siemens tools
ODB++
Open standard requirement
IPC-2581
Ansys analysis import
IPC-2581B
Maximum IP protection
IPC-2581 with FAB mode
Useful Resources
Cadence Documentation
Resource
Description
Allegro PCB Editor Documentation
Official reference
Cadence Community Forums
User discussions
Cadence Support
Technical assistance
IPC-2581 Resources
Resource
URL
IPC-2581 Consortium
ipc2581.com
Free Viewers
ipc2581.com/free-viewer
IPC Standards
ipc.org
Viewer Downloads
Tool
Source
Vu2581
downstreamtech.com
DFM Now!
numericalinnovations.com
ZofzPCB
zofzpcb.com
Frequently Asked Questions
Where is the IPC-2581 export option in Cadence Allegro?
The IPC-2581 export is located under File → Export → IPC2581 in Allegro PCB Editor. Some versions may show it as Export → IPC 2581. If the menu option does not appear, verify that your Allegro license includes the manufacturing output features. The IPC-2581 export functionality is included in most Allegro PCB Editor configurations, including OrCAD PCB Designer Professional.
What is the difference between IPC-2581 versions 1, A, B, and C in Allegro?
Version 1 is the original 2004 specification with basic manufacturing data. Version A (2012) added enhanced fabrication details. Version B (2013) introduced back drilling specifications, improved drill type definitions, and padstack library references. Version C (2020) is the most comprehensive, adding flex stackup definitions, bidirectional DFX data exchange, embedded component specifications, and 3D model integration. For most manufacturing workflows, Version B provides the best balance of compatibility and features. Use Version C only when your manufacturer specifically supports it.
What functional mode should I select for IPC-2581 export?
The functional mode depends on who receives the file. Use FULL for internal use or trusted turnkey partners who need all design data. Select FAB when sending to fabricators who only need bare board manufacturing data, which protects component and assembly information. Choose ASSEMBLY for assembly houses that need placement and BOM data. Use TEST for test service providers. Select USERDEF when you need custom control over exactly what data is included, which is particularly useful for analysis tool imports like Ansys SIwave.
How do I configure layer mapping for IPC-2581 export in Allegro?
Click Layer Mapping Edit in the IPC2581 Export dialog to open the layer mapping table. Assign each design layer to the appropriate IPC-2581 layer type: outer copper to OUTER, inner signal to INNER, plane layers to PLANE, solder mask to SOLDERMASK, paste mask to SOLDERPASTE, and silkscreen to SILKSCREEN. Documentation layers like assembly drawings and fab notes should be assigned as DOCUMENTATION type. Click OK to save the mapping before export. Incorrect layer mapping is a common cause of manufacturing errors, so verify all assignments carefully.
Can I protect intellectual property when exporting IPC-2581 from Allegro?
Yes, Allegro provides multiple ways to protect IP during IPC-2581 export. Use the FAB functional mode to exclude component and assembly data when sending to fabricators. Select specific data elements in USERDEF mode to include only necessary information. The IPC-2581 format itself provides better IP protection than Gerber because the XML structure is difficult to reverse engineer into a usable design database. You can also export separate IPC-2581 files with different functional modes for different supply chain partners, ensuring each receives only the data they need.
Best Practices for IPC-2581 Export
Following consistent practices ensures reliable manufacturing data generation.
Before Export
Complete DRC and verify design integrity. Ensure layer stackup is fully defined in the Cross Section Editor. Verify all component footprints have correct properties including manufacturer and part number. Confirm drill data is current and complete.
During Export
Select the appropriate IPC-2581 version based on manufacturer capability. Choose the functional mode matching your recipient. Configure layer mapping for all design layers. Enable Vector Text for universal compatibility. Enable compression to reduce file size.
After Export
Review the export log for warnings or errors. Verify output using Vu2581 or another free viewer. Confirm layer count matches design. Check that component count and BOM are complete. Send the compressed file to your manufacturer with clear revision identification.
The IPC-2581 export from Cadence Allegro provides a comprehensive, single-file alternative to traditional Gerber-based manufacturing packages. With proper configuration of version, functional mode, and layer mapping, you can generate accurate manufacturing data while maintaining appropriate intellectual property protection for each partner in your supply chain.
Inquire: Call 0086-755-23203480, or reach out via the form below/your sales contact to discuss our design, manufacturing, and assembly capabilities.
Quote: Email your PCB files to Sales@pcbsync.com (Preferred for large files) or submit online. We will contact you promptly. Please ensure your email is correct.
Notes: For PCB fabrication, we require PCB design file in Gerber RS-274X format (most preferred), *.PCB/DDB (Protel, inform your program version) format or *.BRD (Eagle) format. For PCB assembly, we require PCB design file in above mentioned format, drilling file and BOM. Click to download BOM template To avoid file missing, please include all files into one folder and compress it into .zip or .rar format.
