Hi Gordon,
Methinks there is somewhat of a circular argument going on, and that your 
reply was somewhat tongue-in-cheek.
By definition, 'Black Pad' means that there is enough P on the Ni 
surface/interface to both turn it [at least partially] dark grey/black and to weaken it 
sufficientl to cause brittle interfacial failure [BIF] between the Ni and the 
Ni-IMC, when sufficient stress is applied to overcome whatever adhesion 
strength exists.
While there are of course other causes for the BIF failure mode, even at the 
Ni/IMC interface, if more P can prevent BIF due to 'Black Pad' we are talking 
about a different mechanism.
If BIFs are caused by "the board fabricator letting the phosphorus 
concentration in the electroless nickel plating bath get too low,' than what results is 
not 'Black Pad'—by definition.

Werner

-------------------------------------------------------------------------------Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Leadfree
To temporarily stop/(start) delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL/(MAIL)
Search previous postings at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-------------------------------------------------------------------------------