Hi Phillip -
     
     Kirkendall voiding is a diffusion type phenomena that typically 
     involves gold finishes. The diffusion of the gold molecules occur so 
     fast that the diffusion physics become one sided and material can not 
     diffuse fast enough to replace the vacated gold molecule locations. 
     This results in voids and since Kirkendall first discovered/proposed 
     the diffusion mechanism his name has become associated with the 
     phenomena. Take a look at "Feinstein and Bindell, The Failure of Aged 
     Cu-Au Thin Films by Kirkendall Porosity, Thin Solid Films 62, pg 37-47 
     1979" - it may be a helpful reference. Good Luck.
     
     
     Dave Hillman
     Rockwell Collins
     [log in to unmask]
     


______________________________ Reply Separator _________________________________
Subject: Kirkendall Void
Author:  [log in to unmask] at ccmgw1
Date:    4/11/97 11:25 PM


I've been stumped by a phrase which one of our Japanese customers used in a 
correspondence with us recently.  The phrase is "Kirkendall void" and the 
context it was used in is:
     
"There are some electrode that are gold plated and also solder welded.  If 
there is gold at solder welded part, Kirkendall void may be formedm 
resulting pealing."
     
     
It is possible that the CCA they were looking at has gold plated leads 
installed on gold plated PWBs and reflowed with Sn63Pb37 solderpaste.
     
Any help would be gratefully accepted,
     
     
Regards,
     
     
Phillip A. Bavaro
Senior Manufacturing Engineer
[log in to unmask]
(619) 658-2542
     
     
*************************************************************************** 
* TechNet mail list is provided as a service by IPC using SmartList v3.05 * 
*************************************************************************** 
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   * 
* with <subject: subscribe/unsubscribe> and no text in the body.          * 
*************************************************************************** 
* If you are having a problem with the IPC TechNet forum please contact   * 
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      * 
***************************************************************************
     

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   *
* with <subject: subscribe/unsubscribe> and no text in the body.          *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************