Hi Vijay,
The way standards, or guidelines or any other industry document are
generated, is that there is a large enough group of people concerned enough
to be willing to volunteer some of their--or their companies--time. That's
how things get done in the IPC at least. That is why J-STD-001 and IPC-D-279
came about.
On accelerated testing we have tried with IPC-SM-785, 'Guidelines for
Accelerated Reliability Testing of Surface Mount Solder Attachments' and many
in the industry are heeding the information in it, but many are doing their
own thing. I guess you can lead the horse to the water, but...
On getting agreement on modeling I think the situation is hopeless. We have
tried a number of times in the past to get things together (Darrel Frear,
Sandia, organized two meetings for this purpose in Santa Fe in 1990 and 1992
from which resulted two books 'Solder Mechanics, A State of the Art
Assessment', TMS Monograph, and 'The Mechanics of Solder Alloy
Interconnects', Van Nostrand Reinhold, and TMS is having their Annual
Meeting, February 10-13 in Orlando with the theme 'Design and Reliability of
Solders and Solder Interconnects'). The problem is that the academics like
high precision and a model encompassing everything, which leads to high
complexity, many assumptions, and a possible decline in accuracy, and the
people in the trenches--like myself--who see gross errors in designs or no
reliability assurance done in many cases, want a model that is fairly simple
(otherwise people will not use it), hitting the first-order parameters
affecting reliability, and relating to the real world, not one that covers
all possibilities. There are simply too many entrenched positions based on
highly divergent purposes and outlooks.
Werner Engelmaier
Engelmaier Associates, Inc.
Electronic Packaging, Interconnection and Reliability Consulting
23 Gunther Street
Mendham, NJ 07945 USA
Phone & Fax: 201-543-2747
E-mail: [log in to unmask]
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