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22 The PCB Design Magazine • March 2014 optimum stackup. He'll reveal the details on March 24 in a presentation at IPC APEX EXPO in Las Vegas. In fact, RevB eliminates the need for any drawings among the design data to con- vey build intent. Carter explains, "We can render directly from an IPC-2581 file what otherwise takes several sets of drawings." He then re- ferred to a network line card that has cutouts for optical mod- ules, which was fabricated three-up per palette by sev- eral manufacturers as a dem- onstration project. "There were the V-scores and the mills and drills, which along with the stack- up structure used to involve a couple of different draw- ing sets," Carter continued. "Now, no drawings are re- quired at all. You've got the specific tools spelled out in the file that are required for the V-cut, where those V-cuts are located, all described in a spec tied to that V-groove. The details on the milling outline can be described by '2581 so you know how that cutout is achieved. And by the way, back-drill information is also conveyed by '2581, so there's no requirement to specify that in a separate file set." The upshot is that the revised standard now in place reduces the number of files for export to just one, but provides much more thorough and coherent documentation to clarify build intent than the legacy method of conveying a design to manufacture. This will include as- sembly operations. But wait, there's more on the horizon. Carter envisions a bridge to product lifecy- cle management (PLM) environments, which integrate all data about a product from a sys- tems perspective from cradle to grave, includ- ing but far from limited to parts and production processes. As he explained, PLM is intended to be a part-centered view of any object, which encompasses all the attributes that define each part of the object and whether those part de- scriptions apply to the preliminary stages of product development, whether a part is actively being sourced for the product, or whether it is obsolete. But Carter described a hook within the stan- dard that could tie to more than hardware de- scriptions. "Contained in IPC-2581 is the abil- ity to include external references to firmware configuration," he said, "so this is another aspect of the PLM story. I could export de- sign data from my CAD tool into the PLM environment and thereby bring up a prod- uct configuration function that will be identified through the attributes I've assigned parts: 'Hey, I'm programma- ble. I need my reference guide to be related to a binary file that contains the program in- formation that manufactur- ing needs to inject during the assembly process."' Most likely, the IPC-2581 file will merely point to an external file that could have a part number, which would be the program file. Carter added, "I believe there's even the ability to inject that into a dictionary inside IPC-2581, but I don't think I would ever do that. It would add too much burden to the size of the design file." He speculated about sometime merging such mechanical elements as 3D rotatable parts views with the IPC-2581 domain. That's a story for future iterations of the standard. Meanwhile, at the moment, RevB is the most flexible, com- prehensive way to document a design so that a PCB manufacturer will understand exactly what you intend to be built. PCBDESIGN design for manufacture Amit Bahl directs sales and marketing at sierra Circuits, a PCB manufacturer in sunnyvale, CA. he can be reached by clicking here. The upshot is that the revised standard now in place reduces the number of files for export to just one, but provides much more thorough and coherent documentation to clarify build intent than the legacy method of conveying a design to manufacture. " " DOCuMENTING INTENT WITH IPC-2581 continues