The crossover between ECAD and MCAD

4 min read

At an industry event earlier this year, the speaker asked all those in the room who were mechanical engineers to raise their hands. A sea of arms shot skyward. He next asked only those who were solely mechanical engineers to keep their hands up. Barely any hands stayed up.

The point, obviously, is that there will be very few people reading this whose work as a design engineer does not take in other disciplines. And chief among these disciplines in this increasingly mechatronic world is electronics. Given that CAD software is a core tool of the design engineer, it is no surprise that mechanical CAD software and its electronic (ECAD) counterparts have been getting ever closer over the years. This process has accelerated of late, with many mechanical and electronic players announcing joint ventures and collaborations. One of the more recent of these was from RS Components, whose product DesignSpark Mechanical (see Eureka, October 2013) involved the adoption of mechanical CAD software in the form of direct modelling package SpaceClaim to design enclosures for engineers at all levels now have access to 3D design, without the need to rely on traditional expensive 3D software, or the skill of CAD specialists. DSM allowed designers to import IDF files from PCB design tools such as Altium and PADS into the mechanical designs. During its launch, it was abundantly clear that this product was designed to address the increasing overlap between electronic and mechanical design, with quotes from electronic designers saying things such as "The mechanical design stage is increasingly coupled with PCB design" and "there's a real need for some common ground between us and the mechanical engineers". This trend has been echoed in other areas, with many PCB design tools having integrated 3D viewers and offering IDF outputs for use in MCAD tools. More recently, however, things have gone further. One such example came from Altium, which earlier this year announced the launch of announced the availability of the new SolidWorks modeller for Altium Designer. The app was developed by ECAD / MCAD collaboration experts Desktop EDA is the result of Altium's first add-on app development partnership. Altium's first app developer partner using the new DXP 2.0 platform, Desktop EDA, has more than 16 years experience in developing 3D MCAD integration tools for electronics design systems like Altium Designer, Protel and Mentor Graphics PADS. Released earlier this month, the Desktop EDA offering includes apps that extend Altium Designer's native 3D PCB design features by facilitating advanced collaboration between MCAD and ECAD designers. Altium is currently working with other developers to bring additional apps to electronic designers and is targeting a wider release of the distribution and licensing system later this year. This model of apps for ECAD design appearing on MCAD platforms is by no means new, but is set to grow, according to John Isaacs of Mentor Graphics. "One of our strategies has long been that we take one of our softwares like FlowEFD and embed it in those mechanical systems. For instance SolidWorks' flow simulation product is, in fact, a rebranded FlowEFD. It's also embedded in Creo, in Siemens NX and CATIA and what we mean by embedded is that it's just another button on the menu. The user can push that button and they're immediately into FlowEFD. We basically use the same model – there's no interface." In addition, Mentor also released FlowTHERM XT earlier this year, following its acquisition of Flowmatics, a whose past and expertise resided largely in the mechanical sphere. Says Isaac: "FloTherm XT was a significant step in blurring the line between mechanical and ECAD. It basically supports thermal management from design all the way to verification. So a mechanical designer may start by designing an enclosure and maybe a PCB guy will start a conceptual version of the PCB, placing the basic representations of the thermal components on the board to allow analysis to begin with Flowtherm XT really early in the design process. And then, as the design process continued, the interface between the mechanical and PCB sides of things is enabled seamlessly. So now, if a PCB is being designed in detail, they can easily determine if they have a good heat management system in place." Interfaces go seamlessly into FlowThermXT from both the mechanical and ECAD side. Those interfaces have filters that filter out all the non-thermal information, which prevents the analysis being slowed down by extraneous information. According to Isaac, while collaboration between the ECAD and MCAD sides of things is no new thing, the moves towards integration are increasingly a necessity. He says: "Integration is more a question of interdependency than anything else. Electronic products are using integrated circuits that are getting hotter and hotter and closer and closer together on the product thanks to advances in PCB technology. The heat density of these products is increasing and is past the point where you can afford not to use good thermal analysis... we see that blurring the line between mechanical and ECAD is increasingly important." Steve Chidester, head of international marketing for Zuken, agrees about the increased levels of crossover, but makes clear the limits of this phenomenon, saying: "There is a blurring of the two worlds, but it's from an analysis point of view – not from a design point of view. You'll always design a PCB on a dedicated PCB design platform and you're still going to design an enclosure in a mechanical CAD package." That said, however, Chidester has still seen a lot of change in the degree to which MCAD and ECAD users are having to collaborate. "I started out as a PCB designer many years ago and I'd very rarely talk to the MCAD guys. I'd get maybe a printout of an enclosure to make sure my board would fit with it, but more usually, I'd just be told what my restrictions were and if I followed the rules, things were going to fit. The only time the discussion would take place was if I couldn't follow the rules for some reason." Today, however, as the number of components and computing power has to increase within a given space envelope, it has become impossible for the two disciplines not to work together. Says Chidester: "When I've engaged with mobile phone companies, they tell me that they have had to go back and forth between PCB design and MCAD more than 100 times. And that was because the form factor of the phone was set – a phone can only be a certain size. Now the electronics that go into a phone have to all sit in a PCB – all the components, everything. Now in order to make that happen, a huge amount of collaboration has to take place between ECAD and MCAD." This collaboration, he believes, is only set to grow. "Communicating with the MCAD players is essential for us because our customers are their customers to some extent and vice versa. Not only do they have to know each other's work, they have to have to be able to share data and they have to be able to talk to each other. You can't just throw it over the wall anymore, which is what they did when I was a PCB designer. Today they've got to talk to each other otherwise you end up going back and forth between the two departments. It's a lot of time and it's a lot of data that has to be translated. As CAD vendors, we are there to act as translators."