"No designer I know of who has successfully transitioned to the metric unit system for PCB layout wants to go back to the imperial unit system. That statement alone says it all."
That surely is true for everything. This is what was said in the British Parliament when the British were first considering converting to metric - in 1862, almost 150 years ago: "...no nation which has adopted the Metric system has failed to derive the greatest benefit from such adoption, or, after adoption has shown any desire to abandon it." - Report from the Select Committee on Weights and Measures, 1862. John F-L ----- Original Message ----- From: Pat Naughtin To: U.S. Metric Association Cc: USMA Metric Association Sent: Thursday, June 09, 2011 7:29 AM Subject: [USMA:50580] PCB chip design layout Dear Don, Here is another success story that you might like to add you your collection. For everyone else, you might like to give this man as much support as you can. He writes, in part: ## The metric unit system is one of the greatest secrets to PCB design perfection today. From 1974-1991, we used inch units for our PCB layout. >From 1991-2001, we used mil units. From 2001-2011 we used millimeter units. I have to say that when we made the transition from mils to millimeters, our productivity levels slipped a bit during the learning curve. But after five or six PCB layouts, our productivity was back to normal. And after about 15 PCB layouts our productivity levels surpassed all previous results. If I were forced to go back to the mil measurement system, my productivity levels would reverse. There is no way in the world that anyone in 2011 using mil units can outperform the same talent using millimeter units, because most component pin pitches are on a millimeter grid system (like the 1 mm pitch BGA) and metric units are vastly superior to work within the PCB design space. All of the numbers are evenly divisible by 10 and there is no need for calculators for mathematical calculations. No designer I know of who has successfully transitioned to the metric unit system for PCB layout wants to go back to the imperial unit system. That statement alone says it all. ## See http://www.pcbdesign007.com/pages/zone.cgi?a=77073&artpg=1&topic=0 for the full text. Cheers, Pat Naughtin LCAMS Author of the ebook, Metrication Leaders Guide, see http://metricationmatters.com/MetricationLeadersGuideInfo.html Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com for more metrication information, contact Pat at pat.naugh...@metricationmatters.com or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter to subscribe.