Gary,
                        The gold plating solution that comes with our gold
finger repair kit contains the gold suspended in cyanide, and is dark purple
in color. If this same type of solution is used at the fabricator and was
not cleaned completely, it may be bleeding out under elevated temperature.
Not the scientific answer, but something to investigate.

                Mike McMonagle

                                -----Original Message-----
                                From:   Gary Camac
[mailto:[log in to unmask]]
                                Sent:   Monday, August 28, 2000 1:45 PM
                                To:     [log in to unmask]
                                Subject:        [TN] Staining on edge
connector

                                 << File: Card for Gary Camac >> Good
morning all,

                                I have come across something I have never
seen before and thought it would be a good idea
                                to see what my panel of experts have to say.
I have some assemblies that are showing a
                                purple stain in the laminate around the gold
contacts of a board edge connector.  Under
                                the microscope,  I see no sign of anything
on the laminate on the boards from stock.   I
                                took a sample of the stock boards and ran
them, unpopulated, through the reflow oven and -
                                lo and behold - I've got a stain.  The stain
seems to be in the epoxy.  A little light
                                scratching with a knife blade takes off
something purple.

                                Any ideas as to what I am looking at?

                                Gary Camac

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