Phil's memory is correct.  

Norma Lee Todd of Unisys along with Ann Garrison of Goddard Space Flight 
Center presented a paper "How Much Rework is Too Much?: The Effects of 
Solder Joint Rework on Plated-Through Holes in Multilayer Printed Wiring 
Boards."  The paper was presented at IPC Printed Circuits Expo '94 in 
Boston MA.

Regards
***************************************************
David W. Bergman, Technical Director
IPC
2215 Sanders Road
Northbrook, IL  60062-6135
708-509-9700 x340 Phone
708-509-9798 Fax
email  [log in to unmask]
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On 8 Jan 1996, Phillip R Barela wrote:

> 
> Jon Jahn wrote:
> "Can anyone point me toward that information again or alternatively suggest any 
> other references which will help us update this rework guideline?"
> 
> 
> The results of the study were published out of Goddard Space Flight Center 
> (GSFC).  If my memory serves me right, this study was performed to see how many 
> times and what techniques could be successfully used for PTH PWBs.  I believe 
> its focus was on via reliability.  
> 
> Contact Jack Shaw at GSFC (301/286-7123).  Jack works in the electronic 
> packaging branch at GSFC and can probably get you a copy of the report.
> 
> Phillip Barela
> Jet Propulsion Lab
> _______________________________________________________________________________
> Subject: NASA rework study
> From:    [log in to unmask] at Internet
> Date:    1/8/96  2:02 PM
> 
> About a year I read an article which referenced a NASA study in discussing
> maximum allowable solder joint rework cycles. Can anyone point me toward
> that information again or alternatively suggest any other references which
> will help us update this rework guideline?
> 
> regards,
> 
> Jon Jahn
> Marquip, Inc.
> [log in to unmask]
> 
>