Exporting A PCB Design to Mechanical CAD Tools: Multisim, Ultiboard and LabVIEW
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NI Multisim, NI Ultiboard, NI LabVIEW and SolidWorks
Professional users of design tools such as Ultiboard, often need the flexibility to export their designs to different formats and standards for further analysis. In this whitepaper we discuss the need for an Ultiboard PCB design be exported to the Mechanical CAD tool, SolidWorks, to analyze the project.
We discuss the use of the LabVIEW graphical programming language to facilitate the export, with a custom application built to make the connection between National Instruments design tools and SolidWorks.
The application is also available for you to download and use for your own design purposes.
The Design Application
The real-world application, involved the design of a module for a remote environmental monitoring system with Multisim (capture and simulation) and Ultiboard (layout and routing). This monitoring system needed to provide real-time temperature analysis at high accuracy and to a fine resolution. Due to the portable nature of the monitoring system, this compact, all in one design, can allow engineers, scientists and technicians to measure and log temperature data to ensure that systems are maintained without being negatively effected by internal and external heat sources.
The Challenge
A Texas based design company, responsible for the design and implementation of sophisticated distributed temperature sensing system, needed to ensure the effective implementation of a sensor module. In this design they not only needed the validate performance of a design from a board-level simulation, but also to verify the thermal properties of the board.
It is advantageous to export a PCB board from the layout application such as Ultiboard to a mechanical CAD format to be able to rearrange or adapt the mechanical layout of the board for alignment, interference, airflow or other types of placement or cooling analyses.
The Solution
The NI Ultiboard PCB layout tool has native CAD export capability to IGES and DXF (3D) formats which are supported by most mechanical CAD packages. However, these natively supported formats do not allow for separation of the component objects from the board object. This means that mechanical CAD programs will usually treat these entities as a single, monolithic object, composed of a set of polygon shapes.
The IDF format does allow for the separation of the various elements of the board, and is the generally accepted way for separating PCB component objects (ECAD to MCAD). To make this conversion from the standard formats, the Ultiboard IDF Converter was developed in the LabVIEW graphical programming language to expand the capabilities of the National Instruments PCB design flow to more complex and advanced design analysis.
This capability to leverage a graphical programming language to create new tools for the design flow is unique to LabVIEW and National Instruments design tools.
The Ultiboard IDF Converter takes the available DXF export data from Ultiboard and facilitates the creation of IDF board placement and component files based on the IDF v3 standard. The IDF Converter is available to you below, for your own use in your designs.
Using the Ultiboard IDF Converter
From this paper, you will be able to download the Ultiboard IDF Converter Tool, a help resource, as well as gain insight into the various steps needed to complete a design and use the converter tool.
Setup and Installation
- Download the Ultiboard IDF Converter Tool (note this installer is 54 MB in size)
- Download the HTML help document for further details
- Unzip the compressed file
- Run the attached setup.exe file to install
- Download and view the IDF Converter tool help file (note this resource is also included in the installed folder)
- Select Start > All Programs > Ultiboard IDF Converter Tool v2 > UltiboardIDF to run the tool.
The Design Flow
The Ultiboard IDF converter plays an important role in the design flow for those engineers who wish to extend their analysis to the mechanical/physical properties of the board.
Let us begin by seeing how the converter fits into the design flow:
- Define a circuit design in Multisim, analyzing, validating and verifying the performance with simulation. Learn more.
- In Ultiboard, create the PCB design file. It is important to ensure that the 3D mechanical data is present. Learn more.
- Export DXF layers and Part Centroid files from Ultiboard.
- Generate the IDF files (.emn, .emp) from these DXF files using the Ultiboard IDF Conversion Tool.
- Import the IDF format into Solidworks (or other mechanical CAD tool) using the IDF Modeler.
Designing in Ultiboard
In Ultiboard you can layout and route a board. In this example you can reference the attached Ultiboard file IDF Example PCB w Holes.ewprj. Below is the example file. You will notice that this is not a routed board, however does have all the various components placed, and a defined board outline.
Exporting the Parts Centroid Report and DXF Files
Ultiboard can export a number of industry standard design formats. including a Parts Centroid Report (a co-ordinate based report on the center of each component with respects to the board outline), 2D DXF (a 2D format used by mechanical CAD tools to view a design), and 3D DXF (a 3D format used by mechanical CAD tools to view a design).
These can all be exported from Ultiboard by selecting File > Export.
To export the Parts Centroid Report select Part Centroid in this dialog box.
To export the 2D DXF file format, select DXF in this dialog box.
To export the 3D DXF file format, select 3D DXF in this dialog box.
To learn more about the exporting process, consult the following resource on Exporting Gerber Files.
You can also consult the HTML help document attached to this paper for further details on using Ultiboard to export the associated files.
Ultiboard IDF Converter
The Ultiboard IDF Converter is a LabVIEW application created to assist in the export process. It is free to be used by any customer.
It is important to note that this is a LabVIEW application, and is not supported as a standard purchasable application. Please verify the accuracy of the output data from the IDF converter with expected data from Ultiboard and your mechanical CAD program.
The IDF Converter allows you to take the various export data from Ultiboard and build an IDF image of the board that can be imported by Mechanical CAD tools such as Solidworks. The data can be previewed in a 3D format and configured for export.
By inputting the Parts Centroid and DXF files to the IDF converter, you can process and produce an IDF format of the circuit design, to be further analyzed. By taking information from the DXF files, a board outline is built and with the 2D and 3D DXF files, a complete representation of the physical elements of the board are rendered. Finally, the parts centroid data allows the IDF converter to ensure the proper physical placement of all elements of the design.
This is all done simply selecting the IDF File tab, and browsing to the appropriate Parts Centroid and DXF files. Click on the Load button to load the data into the application.
Simply move to the Output tab to click on the Generate IDF button, and create an IDF file to be used within a mechanical CAD application.
For the purposes of viewing the IDF representation, the Preview tab, will allow you to toggle between various views of the new format of the PCB.
You can also consult the HTML help document attached to this paper for further details.
SolidWorks
The final step in this design flow is to view the IDF file in a mechanical CAD application such as SolidWorks in order to fully analyze the properties of the board, whether temperature, air flow etc...
To import into SolidWorks, one needs to simply utilize the IDF Modeler tool within Solidworks. By selecting File > IDF Modeler > Import IDF, the IDF files previously generated can be modeled, viewed and analyzed.
Expanding the Design Flow with Multisim, Ultiboard and LabVIEW
National Instruments is unique in its capability to expand its design flow through the integration to the graphical programming language of LabVIEW.
This is but one application of a design team utilizing the expansive environment of a National Instruments platform to define the functionality, and capabilities to appropriately improve productivity for the PCB design flow.
The Ultiboard IDF Converter, is an example of how National Instruments provides the best practices to the design team. The flexibility of LabVIEW has been utilized as the channel to truly improve the validation of a design, from expanding the sets of analyses available.
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