George,

You have raised some very interesting and pointed questions.

A comprehensive effort by the IPC or another organization is needed
concerning electroless nickel. The need is clear due to the approaching
leadfree
deadline. Nickel plating on components and PCBs present challenges that
are
not clearly delineated. This situation must be corrected and some
common public domain information provided.

This "nickel" issue has now been muddled around with for over 3 years.
I have personally had some testing done on barrier nickel (under gold)
soldered pins that indicated the almost total lack of phasing of the
solder to
the nickel layer. This was done in 1993. About 5% of the surface area
showed "icicle" tearing when the pins were pulled out of the joints.
This raised questions about the joints ability to withstand shock.
At this point the testing was halted. Management decided to wait for
field failures. I departed the company before any reported failures
arrived but the test results have left me with serious questions.

The reduced joint sizes, SMT, increased junction temperatures,
and the expanding use of hardware into harsh and critical situations
are creating a growing urgency for some answers!

David A. Douthit
Manager
LoCan LLC

George Milad wrote:

> The firgure reported by Glazer from Hp for gold embrittlement was 3%
> and not 0.3%. The total amount of gold in ENIG if the new IPC 4552
> specification is followed is less than 5 micro-inches or 0.12 microns.
>
> If one does the math, then it is evident that under these conditions
> "Solder Joint Gold  Embrittlement" is a non issue for ENIG.
> Of course this is all on the board side and not the component. If
> there is an issue with component side separation, the target
> investigation should not be on ENIG leaving the true cause
> unidentified or addressed.
> Blaming the ENIG finish idiscrimanetly, and using the "black Pad" as a
> catch all leaves a lot of areas, where things could go wrong,
> unidentified and more important not corrected.
> Blaming the "Black pad" is prevalent. I often wonder how prevalent the
> ture cases of "Black Pad" are?
>
> George Milad
> Uyemura International Corp
> Chairman IPC Plating Commitee
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