For those interested, one of our staff scientists has noted that failures
can be induced by marking the back side of die with appears to be a laser
of the wrong wavelength. One of the most common wave lengths presently used
is also one that transmits the greatest amount of energy though the die
with a high potential for damaging the active circuitry on the opposing
side. This is due to silicon's near transparency to the given wave length
(1064nm). The study was done by Dr. Belgacem Haba. While the study will be
part of a forthcoming technical article, we thought it could be of
significance to those presently involved in packaging and marking IC's and
to give the industry and early "heads up". If you have interest or need for
more detail, please contact either me or Dr. Haba direct at [log in to unmask]

Regards to all,
J. Fjelstad

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################