iow, metric is for wimps. make mine 50 cal not 12.7mm. /heh At 06:23 AM 10/17/2009, Kenneth Wood wrote: >The USA played golf on the Moon 40 years ago using that old arcane and >archaic system...Metric system countries that have played golf on the Moon? >Oh yeah...none >:) > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Joe Fjelstad >Sent: Friday, October 16, 2009 4:41 PM >To: [log in to unmask] >Subject: Re: [TN] No Soldermask between Fine pitch QFN and QFP > >Hello Amol > >Since all electronic components are now designed, registered and fabricated > using the metric system, would not it be easier to ask for a 0.5mm pitch >device with lands of 0.25mm by 0.7mm? > >This is one of the windmills I continue to joust and I am constantly >curious why we in the US continue to be so wedded to such an arcane and >archaic >measurement system as that which we inherited/adopted from our English >forefathers. > >Consider the following from the web: > >The metric system originated in France in the 1790's, a few years after >Jefferson's proposals. (note: Jefferson proposed to metric English system >for >the US in the 1780 time frame where there were to 10 inches to the foot, >10 feet to a decade, 100 feet to a rood, 1000 feet to the furlong and >10,000 >feet to the mile) During the mid-nineteenth century, as expanding trade >demanded a consistent set of measurements, use of the metric system spread >through continental Europe. As they imported goods from Europe or exported >goods to Europe, Americans became increasingly aware of the metric system. >In >1866, Congress legalized its use in an act reading: >It shall be lawful throughout the United States of America to employ the >weights and measures of the metric system; and no contract or dealing, or >pleading in any court, shall be deemed invalid or liable to objection >because >the weights or measures expressed or referred to therein are weights or >measures of the metric system. >As a result, the U. S. has been "metric" since 1866, but only in the sense >that Americans have been free since that time to use the metric system as >much as they like. Although there has always been popular resistance to >changing the traditional measures, the metric system has actually enjoyed >strong support from American business leaders and scientists since the late > >nineteenth century. In 1875, the U.S. was one of the original signers of >the >Treaty of the Meter." >and I might add that we continue to move towards complete metrication of >our national measurement systems "inch by inch"... ;-) >Joe > > >In a message dated 10/16/2009 10:55:25 A.M. Pacific Daylight Time, >[log in to unmask] writes: > >I am looking at a 19.7 mil pitch QFN device with a center pad and >peripheral pads at 9.8x27.5 mils, and a 176 pin fine pitch QFP with 11.8x63 >mil >pads with HASL finish and without any soldermask in between the peripheral >pads!...has anybody seen this type of a board design before? Any stencil >design suggestions? > >I have a couple of pictures I have requested Steve to post for me >regarding the parts ( I am awaiting Steve's reply) > > >Thanks, >Amol > > > > > >WARNING: Export Control >This document may contain technical data within the definition of the >International Traffic in Arms Regulations (ITAR), and subject to the >Export >Control Laws of the U.S. Government. Transfer of such data by any means >to a >foreign person, whether in the United States or abroad, without proper >export >authorization or other approval from the U.S. Department of State is >prohibited. > >CONFIDENTIALITY NOTICE: >This e-mail, and any attachments, is for the sole use of the intended >recipient(s) and may contain information that is confidential and >protected from disclosure under the law. Any unauthorized review, use, >disclosure, or distribution is prohibited. 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