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60 The PCB Magazine • July 2014 With respect to Karel, I think he may be missing the main point. Consider this: • No doubt Gerber is a very fine format for defining the graphical layers of a PCB • IPC-D-356 is perfectly fine for defining a netlist • Excellon needs no improvement; it defines the location and diameter of drilled holes quite well. • Component placement lists can define component positions and rotations quite well also • PDF is a good format for rendering drawings • GenCAD and FATF are good for defining the parts of a PCB assembly for testing purposes • Word is good for capturing text, especially "Readme" documents that explain to a CAM engineer how all of the above file-types should relate to each other, and how to reintegrate all that data back together so as to enable an efficient software-driven new product introduction (NPI) process. Certainly, if all you want is accurate graphical data, then I am sure Gerber meets the requirement, and Karel is to be congratulated on his perseverence in improving that particular 50-year-old NC format. At a recent industry debate on this topic, he suggested that the best way forward is to use Gerber for the graphical data and another format for all the other information that Gerber cannot carry. Thus, he promotes the idea of intelligent, all-encompassing formats for carrying data, but excluding the graphical part. Why reject the advantage of having all of that other information linked to the graphical objects as well, and vice-versa? The problem that needs solving is taking all of that fragemented data into a single coherent model comprising both the PCB bareboard and the assembled PCB. Keeping parts of the product-model seperate for simplicity is fine if you are only interested in a narrow subset of the PCB product-model, but it is a big problem if you need a complete definition of the product, as do all DFM and NPI engineers! There is no escape from the fact that, sooner rather than later, the data must be integrated. Reductio ad absurdum: To take the idea to an extreme, maybe there is a drilling expert out there ready to explain that Excellon should be used for holes information, but all of the "other information" (including the layer graphics, no doubt) should be carried in ODB++. Obviously it is absurd to keep part of the PCB product- model (in this case, the holes) separate from all the rest. The first thing a CAM engineer would do in this case would be to read the Excellon file and integrate the hole data into the ODB++—an unecessarily time-wasting and potentially error- prone process. There is a broad consensus across the industry that fixing the highly fragmented nature of the CAD-to-CAM data files problem is long overdue, and that the answer is to implement integrated, Julian Coates' Rebuttal: revised Gerber format is compatible with the previous versions of Gerber and older software, so improvements can be as gradual as users want them to be, with no one being forced to buy new software against their business wishes or budgetary constraints. It is a path that delivers to small software vendors and the industry at large, fixing what is broken without compromising what already works. In short, it's nothing short of revolutionary, but without the complications. The Gerber format specification, a sample X2 archive and background articles on X2 can be found at www.ucamco.com/downloads. Karel Tavernier Managing Director, Ucamco GERBER—THE SMARTEST WAY FORWARD continues

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