Might need to clean the oven.  Could be flux, or some kind of grease or oil dripping off the inside of the oven.  Can it be washed off?  Is it just on the gold fingers?  Is it on just that particular type of board?

-----Original Message-----
From:   Gary Camac [SMTP:[log in to unmask]]
Sent:   Monday, August 28, 2000 12:45 PM
To:     [log in to unmask]
Subject:        [TN] Staining on edge connector

 << File: gcamac.vcf >> 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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