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From:
Jose A Rios <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Jose A Rios <[log in to unmask]>
Date:
Wed, 15 Nov 2017 15:27:39 +0000
Content-Type:
text/plain
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text/plain (157 lines)
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
>>>> 
>>> 
>> 

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