CircuiTree - August 2008 - (Page 28)

Creating Connections Between Electronics Design and Manufacturing instigated to conﬁrm those modiﬁcations, resulting in a protracted and iterative process that does little to encourage MCAD-ECAD design collaboration. Another approach to the problem has been the use of separate, thirdparty design translators to ease ﬁle compatibility issues (for example, IDF, the Intermediate Data Format, is sparsely supported in the MCAD world) and make the process more ﬂexible. These often provide import/export options in the native format of the ECAD-MCAD applications and in some cases connect directly into those programs using object linking (OLEs) or programming interfaces (APIs). To date, both these approaches have fallen short of the ideal. With the basic ﬁle exchange setup, data translation errors are frequent due to limitations and inconsistencies in the exchange format itself and there is little control over the degree of data sent—too much or too little is equally problematic. But, above all, the process is generally clunky and marred by the incompatibilities of weak data exchange formats. Dedicated CAD translation programs generally offer a better outcome, thanks to more rigidly deﬁned formats and data ﬁltering options that allow you to specify what objects are included for transfer. Unfortunately, however, it is often a case of two steps forward and two steps back due to the added layer of translation complexity inserted into the process. The approach can, for example, make the translation process versionsensitive because of its intimate ties to the MCAD-ECAD applications, and it certainly adds another licensing cost to the overall design system. The linked (OLE, API) version of the translator programs can offer a more integrated solution by bolting itself into the MCAD or ECAD application, but the tradeoff is that it then becomes version-critical and the MCAD-ECAD applications must be loaded on the same PC platform so the OLE/API interconnections can be established. level with the relatively new STEP format, which is a data-rich and extremely robust protocol designed for 3D design and manufacturing processes. STEP is now supported by most MCAD systems, so an ECAD solution that supports bidirectional STEP transfer will signiﬁcantly reduce 3D data translation problems through this feature alone. STEP ﬁles can be large, but this can be easily constrained if the ECAD system also offers an intelligent range of object ﬁltering options in the translation interface. Along with ﬁle compatibility beneﬁts, this approach can also remove the complications and expense of thirdparty applications and does not suffer from MCAD-ECAD application version issues. Beyond robust ﬁle systems for design data exchange, the ECADMCAD workﬂow needs to be considered from a productivity standpoint. For example, introducing separate third-party translation and processing applications adds more sequential stages to the process, leading to an increase in workﬂow complexity and the likelihood of recursive errors in critical design data. In short, any solution that introduces multiple ﬁle formats and sequential data translations must, by deﬁnition, increase the risk of slowing and complicating the product development process. Another point to consider is how the 3D data models are created and applied for viewing in the MCAD space. Performing accurate judgments of how the electromechanical parts ﬁt together—in practice, object clearance and interference checking—relies on the availability of accurate 3D object models. At a practical level this means that assembly information passed from ECAD to MCAD must include accurate component models, or those electrical models must be available within the MCAD application where they can be inserted as required. Systems that rely on IDF ﬁle transfer are an example where the included 3D model information is inadequate for accurate clearance checking in the MCAD space. If IDF transfer is used in a standalone translation application that also performs clearance checking, critical models must be replaced with more accurate ones from its own 3D library. Data exported from this application as IDF ﬁles will then lose this more accurate data due to the limitations of the ﬁle format. At the least, this adds yet another layer of translation complexity to the process. In terms of data integrity and workﬂow efﬁciency, MCAD-ECAD connectivity at its basic level is best served by a straightforward approach of passing STEP models directly between the two domains. Tackling the Fundamentals The ﬁrst step in creating a design environment that promotes real design collaboration between the ECAD and MCAD domains is taking a higher level view of the electronic to mechanical design relationship. A core concept here is the current changes in the electronics design industry, meaning that product design must now be thought of as a single task rather than a collection of processes that are ultimately brought together. From a board design standpoint, this means embracing a shared and collaborative approach to design that keeps a ﬁrm eye on the ﬁnal result—a complete electronic product that meets market goals. In turn, this means recognizing developments such as the often dominating inﬂuence of a product’s mechanical design in the board design process and the need for design data exchange systems that work together rather than connect together. What’s needed at a fundamental level then is a reliable, comprehensive, and convenient way to transfer that data between the domains. Existing solutions attempt to bridge the MCAD-ECAD gap though a maze of ﬁle formats and applications designed to stitch processes together. These systems have evolved over time to meet the growing need for design data exchange but in the process have adopted proprietary formats or pressed existing but inadequate ones into service. However, 3D data transfer protocols have now moved to the next 28 August 2008 • circuitree.com Figure 3 Usually Performed in the MCAD Design Space, Clearance and Interference Checking Ensure That the ECAD and MCAD Objects Successfully Fit Together. Transfer of 3D Design Data Must Be Accurate and Reliable 30 http://circuitree.com

Table of Contents Feed for the Digital Edition of CircuiTree - August 2008

CirciuTree - August 2008 Contents My Line Industry Review Tech Talk Flexible Thinking Creating Connections Between Electronics Design and Manufacturing Happy Thoughts View From the Middle Market Outlook Fein Lines IPCA Showcase Technical Product Spotlights Classified Ads Upcoming Events Ad Index Buyers Guide

CircuiTree - August 2008

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