Hi Richard - the guys from the International Tin Research Institute (ITRI)
did some really cool and comprehensive work on solder alloy creep years
back. It published in their Report #656 Solder Alloy Data. The publication
has multiple alloy sets plus good creep, stress rupture and fatigue data.
Good reference to have on the shelf. I use those data sets when making
first order estimations on solder reliability issues.

Dave

On Wed, Nov 15, 2017 at 8:59 AM, Stadem, Richard D <[log in to unmask]
> wrote:

> No, I didn't expect you to, George. I was just wondering outloud about the
> relationship of the wire diameter with respect to time and whether it is a
> linear relationship. I am sure there are other factors such as the exact
> alloy type, etc, but I was just trying to get my mind around the general
> relationship of different sizes of solder joints (and more specifically,
> geometries) and the effect on time to failure for a given loading factor.
> Maybe I'm nuts, but I find the topic very interesting. I do know that even
> minor impurities, and different types, can play a huge role in the creep
> rate of solder.
>
> -----Original Message-----
> From: George Wenger [mailto:[log in to unmask]]
> Sent: Wednesday, November 15, 2017 8:50 AM
> To: Stadem, Richard D; 'TechNet E-Mail Forum'
> Subject: RE: [TN] Question on Loading Solder Joints
>
> Sorry.  It was so long ago I don't remember what diameter solder wire he
> used.
>
> -----Original Message-----
> From: Stadem, Richard D [mailto:[log in to unmask]]
> Sent: Wednesday, November 15, 2017 9:43 AM
> To: TechNet E-Mail Forum <[log in to unmask]>; George Wenger <
> [log in to unmask]>
> Subject: RE: [TN] Question on Loading Solder Joints
>
> 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
> > >
> >
>
>