A 'dirty trick' that could cause no end of confusion with some service guy = someday. That guy won't thank you for doing this for certain even if you ca= n get away with it electrically..... All the same having done a fair bit of SMD routing lately, , I understand t= he temptation. Joe -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of= David VanHorn Sent: 21 October 2014 21:13 To: Microcontroller discussion list - Public. Subject: Re: [EE] NC pin cleverness Sounds like a "dirty trick" that might come in useful once in a great while= .. On Tue, Oct 21, 2014 at 11:19 AM, Denny Esterline wrote: > No great experience to give you a definitive answer. I think you're=20 > just about spot-on with your concerns, but I would look at this as a=20 > risk management exercise. On a one-off hand assembled board, absolutely d= o it. > On a high volume production product, heck no. As is usually the case=20 > in most things, reality probably lies somewhere between the extremes. > > As to #1, I think that a properly designed footprint should have each=20 > pad be a net neutral force during reflow - i.e. center of pad=3D=3Dcenter= =20 > of pin contact area. As such, missing a few pads on one side should=20 > remain net neutral. > As to #2, I wouldn't be overly concerned unless you're working on=20 > something expected to survive "high acceleration events". (think=20 > artillery shell) you're only talking about an 8% reduction in=20 > contacts. I think you'd see a bigger difference than that in the=20 > variance between lead and lead-free solder. > In low volume setting, if you're greatly concerned about #3 - just cut=20 > them off at time of assembly. > > -Denny > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive=20 > View/change your membership options at=20 > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/chang= e your membership options at http://mailman.mit.edu/mailman/listinfo/piclis= t --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .