Mike,
Two other possibilities:
1) that particular part type cooled in such a way that the roughness of the surface of the joints are ridged in such a way that they are diffracting the light such that the light you see is slightly colored
2) a minor impurity from the termination of the part has come to the surface and colored the surface of the joint.
Bev Christian
XLTEK
-----Original Message-----It may be flux that was not cleaned off or exuded out after processing.
From: Dewey Whittaker [mailto:[log in to unmask]]
Sent: Thursday, July 06, 2000 2:11 PM
To: [log in to unmask]
Subject: Re: [TN] Strange Cap Terminations
Dewey"McMonagle, Mike" wrote:
We have recently received a few memory assemblies from an off-shore vendor
that exhibit a copper or bronze hue to the terminations of the bypass caps.
There are only 2 caps on the assembly, and they both show this anomaly. Very
light scraping exposes good looking terminations just under the surface of
the discoloration. All other terminations and leadframes look fine (TSOPs,
Resistors, Tantalum), just this one component looks 'funny'. In addition,
the board appears clean (to the eye) under high magnification. This is a new
one on me, what could be the cause of this?Mike McMonagle
PCBA Process Engineering
Telxon Corporation
(713) 307-2443 Phone
(713) 307-2581 Fax
www.telxon.com' Innovative Solutions for
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##############################################################-- Dewey Whittaker Honeywell -- Air Transport Systems Division US Mail: P.O. Box 21111 MS: M16A2 Phoenix AZ 85036 Phone: +1 602 436 436-2766 NSFnet: [log in to unmask]