Dear all,

I think that 50degC test is very useful.
Supposing that the mechanism of Whisker is recrystallization, the test is most
theoretical.
However, I am not yet convinced of this, because the data is not so enough.
I think that more additional tests are necessary to be convinced of this.
I begin this test from now.
When those test is finished, I will report those results as the paper.
I hope that my paper will be useful.

Thanks,
ICHI SAKAMOTO





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cc:    (bcc: ichizo sakamoto/OMRONJP)
 $B7oL> (B: [LF] Tin whiskers test - proposal for committment



     Hello,

     It is time and place i think to start to take decisions on that
     whiskers growth test .Most of the world wide experts i guess are
     around that forums.

     Among the results we built and we have seen from others , it is clear
     than hot storage above 80 $B!k (BC will reduce whiskers growth , the best
     test to accelerate a room temperature growth (shelf storage) is to
     store at 50-55 $B!k (BC .
     It is may be not the only test to be performed but it must be
     performed .
     The other option is likely to be a humidity & temperature storage
     test which can range from 30 $B!k (BC60%rH which is about room temperature
     of a clasiic store to 95 $B!k (BC-95%rH recently proposed by a forum member
     form OMRON.

     I suggest to move ahead and each forum member to engage its company
     about the necessity to provide storage data at 50 $B!k (B to 55 $B!k (BC in dry air
     when speaking about whiskers.

     Beside lets open the door for a second or third test conditions on
     which you may need more data to all commit and may even be customized.

     Data must be provided with a maximum length which may be drawn from
     the inspection system : for example no whiskers means no whiskers
     longer than X



µm or mils .

     We do need in ST Microlectronics to receive that storage data (at
     50-55


 $B!k (BC) from any supplier ( process supplier or assembly
     subcontractor ) when speaking about coatings with less than 5%
     allowing element.

     Please vote on that proposal


     Secondly i propose to vote also on the accepation of the fact that
     reflow tin , tin dipped coatings do not grow whiskers.


     I am sure that base on that poll results a standard can be prepared by
     IPC or other relevant organizations



        best regards

           Luc P.

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