Design Article
3D modeling integrates flexible PCB design
Manuel Rei, Dassault Systèmes
7/13/2011 7:35 AM EDT
3D adds flexibility
Designing a flexible PCB and making it fit into a complex mechanical housing is a significant challenge. It requires using a sophisticated application of mechanical and electronic CAD tools in order to address the design challenges and removing data exchange limitations. Using CATIA 3D Flexible PCB Design, the end-to-end process is 100-percent digital. There are no workflow breaks or manual operations – figure 1.
A typical use case scenario is to design the mechanical housing, including the shape of the flex board using CATIA. Hardware assemblies containing rigid and flexible boards, and mechanical components are developed first. The flexible PCB board outline is created by mechanical designers using CATIA which also acts as a unified repository for evolving designs.
This means that the PCB board designs created in CATIA remain as digital models throughout their development cycle. The PCB board outlines can be flattened and folded back to their original 3D position.
Critical components are placed in 3D and thereby benefit from a 3D virtual mock-up of the product. This allows them to be located on the board in the correct location, first time – see figure 2.
In many cases stiffeners will be added to the 3D virtual board model. Constraint areas are then added in 3D and the flexible PCB board is flattened using CATIA.
This flattened view of the flexible PCB contains all 3D design information, along with the components and constraint areas. Data is exchanged with the electronic designers and the flexible PCB model is translated to ECAD via an IDF file. All remaining electrical components are placed and coppers/wires are routed in ECAD.
Electronic circuit design and electrical constraints are forward-annotated to the flex board shape and the board outline is created. Automatic placement of electronic components and routing is available. After completion of the board layout, design rule checks are applied, and the board layout is forwarded to the MCAD system. Comparing this new design to the previous one, and updating the MCAD session is key to increasing user efficiency.
Components and copper traces are imported and added to the design and then folded back to their 3D position. Finally, the flexible PCB can be validated against the full 3D virtual mock-up – see figure 3.
Designing a flexible PCB and making it fit into a complex mechanical housing is a significant challenge. It requires using a sophisticated application of mechanical and electronic CAD tools in order to address the design challenges and removing data exchange limitations. Using CATIA 3D Flexible PCB Design, the end-to-end process is 100-percent digital. There are no workflow breaks or manual operations – figure 1.
Figure 1: The end to end 3D design process in CATIA
A typical use case scenario is to design the mechanical housing, including the shape of the flex board using CATIA. Hardware assemblies containing rigid and flexible boards, and mechanical components are developed first. The flexible PCB board outline is created by mechanical designers using CATIA which also acts as a unified repository for evolving designs.
This means that the PCB board designs created in CATIA remain as digital models throughout their development cycle. The PCB board outlines can be flattened and folded back to their original 3D position.
Figure 2: Critical components are placed in 3D to ensure they respect the mechanical design constraints.
Critical components are placed in 3D and thereby benefit from a 3D virtual mock-up of the product. This allows them to be located on the board in the correct location, first time – see figure 2.
In many cases stiffeners will be added to the 3D virtual board model. Constraint areas are then added in 3D and the flexible PCB board is flattened using CATIA.
This flattened view of the flexible PCB contains all 3D design information, along with the components and constraint areas. Data is exchanged with the electronic designers and the flexible PCB model is translated to ECAD via an IDF file. All remaining electrical components are placed and coppers/wires are routed in ECAD.
Electronic circuit design and electrical constraints are forward-annotated to the flex board shape and the board outline is created. Automatic placement of electronic components and routing is available. After completion of the board layout, design rule checks are applied, and the board layout is forwarded to the MCAD system. Comparing this new design to the previous one, and updating the MCAD session is key to increasing user efficiency.
Components and copper traces are imported and added to the design and then folded back to their 3D position. Finally, the flexible PCB can be validated against the full 3D virtual mock-up – see figure 3.
Fig. 3: The flexible PCB can be validated against the full 3D virtual mock-up.
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hm
7/13/2011 10:41 AM EDT
It looks very interesting. Is it possible to have video tutorial with one typical application?
What is approximate cost for this tool?
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MN
7/14/2011 7:08 AM EDT
Catia is about $US15K, although the academic version is only $US99.
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MHK_#1
7/20/2011 11:23 PM EDT
This is useful in a very specific case, such as example with a structural component in a tight space application. From my experience, the most problem in PCB board design case is a lack of communication between a board designer and a logic designer. It would be a super-duper tool, if this tool can not only handle 3D components on PCB layout, but pull a logic design data from FPGA/ASIC chip library and a backplane file. Could this tool do that? Or already doing it?
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RWatkins
7/21/2011 12:37 PM EDT
3D model incorporation as part of circuit design and board layout is indeed quite valuable as our company can attest, especially when developing housings for portable battery powered devices where size and fit are critical design issues.
There are several packages out there that have some degree of 3D capability in them, ranging from KiCAD (Linux freebie with limited capabilities and a somewhat clunky interface for part models) to the $100,000/seat "high-end" systems.
We have only one major issue related to this with the system we are currently using, Altium, that the PCB library models are stored in flat-file fashion so that changing or adding 3D PCB parts models for a moderate sized library can result in a pretty extreme file size and long storage and retrieval times. This issue becomes more extreme the more complex the 3D models are, for example 120-position board stacking connectors like are available from Hirose.
We have one case currently where we have a 4-board stack 65mm x 75mm each board, with two board-board spaces of 3mm and one board-board space of 2mm, and parts on both top and bottom of several of these boards. Without 3D modeling, the effort required would be daunting to avoid collisions between bottom layer parts on one board and top layer parts on the next board down.
One feature that would be nice, if available, would be to also model the copper on and in the PWB as part of the 3D model, as this would help even further in EMC evaluations using modeling software like HFSS. This copper generation should be an option that is NOT default, because the complexity of the model generated will be extreme, resulting in large files and long processing times.
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hm
7/21/2011 1:07 PM EDT
@Rwatkins: Yes, what you mentioned is very much true. I had around 800 parts on my medium size PCB. When I generated step model for it, the size of file was huge. I generally switch OFF 3D models for normal routing. I switch them ON only for verification purpose. This speeds up routing.
Having copper and vias modeled in 3D will be great. Also, when I export Altium 3D model to step model, it removeds some details. The step conversion should also be improved.
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docdivakar
7/27/2011 7:02 PM EDT
Yes, there are solutions available today as @RWatkins mentioned but they cost a lot!
I second the need to model Cu traces and lands on the board. It is very much needed for multiple needs including power management, thermal, EMI, etc.
MP Divakar
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Estelle Fernandez
8/16/2011 5:32 AM EDT
You can as well listen to the e-Seminar posted here : https://3ds.webex.com/ec0605l/eventcenter/recording/recordAction.do?siteurl=3ds&theAction=poprecord&recordID=40564422&pso_3ds_flag=from3dsh
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Manuel Rei
8/16/2011 11:35 AM EDT
Hello All,
Thanks for your comments.
If you would like to have any detailed information on how CATIA V6 can help you designing flexibles PCBs, please contact me. My email is manuel.rei@3ds.com
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Keith-Richman
10/23/2011 11:15 AM EDT
Just a FYI...Simplified Solutions has released IDF-to-3D. This is a web based tool with an integrated 3D library that allows the user to generate 3D PCBs in 1-2 hours. Use of the tool is free and you can view a 3D PDF of your 3D PCB prior to purchasing the output in STEP format.
For more information, please see www.simplifiedsolutionsinc.com
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Haiwang International Electronics
1/30/2013 2:56 AM EST
Haiwang Internationals is professional Quick Turn PCB Assembly manufacturer & Production in China since 2006,Haiwang can meet all your Electronic Printed Circuit Board process needs from double-sided to multi-layerd PCB's and from turnkey PCBA prototype through mass production
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