Issue link: https://iconnect007.uberflip.com/i/1276973
10 DESIGN007 MAGAZINE I AUGUST 2020 Do you hand off perfect fab notes to your fabricator? If this month's content is any indi- cation, the answer is likely, "No." And you may not even know that your fab notes are incom- plete or incorrect because your CAM engineers have been fixing your data for so long that it's become part of their job description. But this isn't about designers handing off bad data; the problem goes much deeper than that. In fact, we really can't blame designers for a situation that they didn't create. The system has enabled designers to con- tinue sending out less than perfect fab notes— in effect, making the board shop's CAM depart- ment the final step in the design process. Some CAM engineers spend eight hours tweaking one data package, often before the fabricator even gets the job. (The CAM department is actually working in sales at that point.) You could play devil's advocate and posit, "If it ain't broke, don't fix it." But there are consequences for the OEM that hands off imperfect data, including time to market (which equals lost revenue) and weekend calls from the CAM department. But these ramifica- tions are all "baked in the cake" at this point, and the actors seem to have accepted their roles. What exactly does a fabricator need from a designer in the first place? We posited that question to Dana Korf, formerly the chief PCB technologist at Huawei. He answered, "Give me all of the data I need to build the board right the first time. Don't tell me how to do it; tell me what you need." That clearly isn't happening very often. Some fabricators say that 90% of all new cus- tomers hand off inaccurate or missing data. But the CAM department's data-tweaking ser- vices make that fabricator an attractive sup- plier. If you're a CAD manager at an OEM, it's easy to think, "We'll get it pretty close, and the CAM people will make it all nice. We're already on The Shaughnessy Report by Andy Shaughnessy, I-CONNECT007 Erroneous Fab Notes: Don't Blame the Designer