Assuming its gage r&r’able, one could make this an IPC-TM-650 method to test solder wire ahead of use. Imagine that. > On Nov 15, 2017, at 10:03 AM, David Hillman <[log in to unmask]> wrote: > > Well, I have one data point: a 0.015 inch diameter cored wire with a ~ half > pound load didn't last the night! It was broke when I got to my desk this > morning. > > Dave > > On Wed, Nov 15, 2017 at 8:43 AM, Stadem, Richard D <[log in to unmask] >> wrote: > >> I wonder what diameter of solder is most useful to demonstrate the >> property within two or three hours, and with what weight? >> >> -----Original Message----- >> From: TechNet [mailto:[log in to unmask]] On Behalf Of George Wenger >> Sent: Tuesday, November 14, 2017 4:42 PM >> To: [log in to unmask] >> Subject: Re: [TN] Question on Loading Solder Joints >> >> I'm about to go out to dinner with my youngest son and my two youngest >> grandsons otherwise I would be downstairs in my work shop hanging weights. >> What I would like to do is hang three solder wires (1ft, 2ft, and 3ft) and >> time the creep elongation for each. I'm pretty sure the weight used by the >> teacher was a 1Kg weight. >> >> -----Original Message----- >> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman >> Sent: Tuesday, November 14, 2017 5:37 PM >> To: [log in to unmask] >> Subject: Re: [TN] Question on Loading Solder Joints >> >> LOL - I have the "test" in progress in my office right now - but the >> solder wire length is one one foot long! >> >> Dave >> >> On Tue, Nov 14, 2017 at 4:31 PM, George Wenger <[log in to unmask]> >> wrote: >> >>> Richard, >>> >>> Although I have a good analytical mind and remember this demonstration >>> very well I may have not gotten the dimension exact. The more I think >>> about it I think the blackboard was 4 ft tall and the solder wire may >>> have only been 2.5 to 3 ft long and the class was all morning >>> (9:00am-11:30) so the solder wire broke before the class was over so >>> it might have broken closer to two hours then one hour. Nevertheless, >> the demo made its point. >>> >>> George >>> >>> -----Original Message----- >>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D >>> Sent: Tuesday, November 14, 2017 5:21 PM >>> To: [log in to unmask] >>> Subject: Re: [TN] Question on Loading Solder Joints >>> >>> I can just hear Bev cutting the 4 ft section of wire solder as I write >>> this.......LOL! >>> >>> -----Original Message----- >>> From: TechNet [mailto:[log in to unmask]] On Behalf Of BEV CHRISTIAN >>> Sent: Tuesday, November 14, 2017 3:37 PM >>> To: [log in to unmask] >>> Subject: Re: [TN] Question on Loading Solder Joints >>> >>> George, Ioan and Dave. >>> Thx! >>> >>> Regards, >>> Bev >>> >>> Sent from Mail for Windows 10 >>> >>> From: George Wenger >>> Sent: Tuesday, November 14, 2017 4:00 PM >>> To: 'Bev Christian' >>> Cc: 'TechNet E-Mail Forum'; 'David Hillman' >>> Subject: RE: [TN] Question on Loading Solder Joints >>> >>> Bev, >>> >>> I'm really an old timer with lots of practical experience and I can >>> remember back in the early 70's taking a class at The Western Electric >>> Corporate Education Center in Hopewell NJ and the teach said that you >>> should never have a solder joint under a tensile load. He continued >>> to say that rather than give you a 1000 words to tell you why not that >>> he would show us a very simple and very graphic demonstration. He >>> pulled a roll of solid solder wire out of his desk and said it was >>> Sn60 but it really didn't matter what the solder alloy was. He cut >>> off a 4 foot length of the solder wire and tied one end to a hook at >>> the top of the blackboard and then tied a weight to the other end of >>> solder wire. He took a chalk and marked a line on the blackboard just >>> where the bottom of the weight was. He then continued teaching the >>> days lesson but every 15 minutes of class, without saying anything, he >>> would take the chalk and mark where the bottom of the weight was. >>> After about a little over an hour, while he was busy instructing us on >>> the days lesson, we heard a loud "bang". The solder wire had >>> continued to elongate while it was under the tensile load of the >>> weight and finally the solder wire broke approximately in the middle and >> the weight dropped onto the floor. Right after every one heard the loud >> "bang' >>> of the weight hitting the floor he stopped what he was talking about >>> and simply said "that is why you never what a solder joint to be >>> subjected to a continuous tensile load". Although it's been almost 45 >>> years since I attended that class I'll never forget what he said. >>> >>> George >>> >>> -----Original Message----- >>> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman >>> Sent: Tuesday, November 14, 2017 3:33 PM >>> To: [log in to unmask] >>> Subject: Re: [TN] Question on Loading Solder Joints >>> >>> Hi Bev - I would point them to RJ Klein Wassink's book "Soldering In >>> Electronics", ISBN 0-901150-24. In the Mechanical Properties Section >>> 8.4 it states "From the data in section 4.7.2 it is obvious that a >>> normal soldered connection on a printed board is not well suited to >>> withstanding a permanent mechanical load." >>> >>> And in Section 4.7.2 Creep, there is some good data on the creep >>> properties of solder backing up that statement. >>> >>> Dave Hillman >>> Rockwell Collins >>> [log in to unmask] >>> >>> On Tue, Nov 14, 2017 at 2:12 PM, BEV CHRISTIAN >>> <[log in to unmask] >>>> >>> wrote: >>> >>>> TechNetters, >>>> A fellow ex-BlackBerry employee sent me the following query. I >>>> obviously no longer have access ot the search capabilities I had at >>>> BB. Can anyone offer any suggestions for papers that will meet his >>>> needs? I mean I know the reason why, but he wants a paper that >>>> proves >>> it. >>>> >>>> I need help with locating a couple of good papers and research >>>> studies that explain why designs that place a constant tensile or >>>> shear load on board connectors(USB, HDMI, RCA, AC inlet etc.) are a >>>> bad idea. Can you point me to a couple of papers on this ? Thanks. >>>> >>>> Regards, >>>> Bev >>>> >>>> Sent from Mail for Windows 10 >>>> >>> >>