The President's Corner
I am proud to present this newsletter as our first in a series of technical
presentations designed to communicate topics of interest to our industry.
In addition to the newsletter, we will be conducting in-house seminars on
topics with the highest level of interest. Our first technical seminar in
the series will be on X-ray Fluorescence (XRF). We have invited experts from
Matrix Metrologies who have decades of experience designing XRF equipment
and standards. For more information about this XRF seminar, click
here.
The No-Pure-Tin vs. Lead-Free Tug-of-War
With blinding speed, the semiconductor industry is adopting pure-tin as
the primary finish for all components except ball grid array. To them, pure-tin
is ideal. Solderability is robust, pure-tin is fully compatible with both
tin-lead and lead-free solders, and implementation is easy. The semiconductor
industry views tin whiskers as a minor reliability issue with the same degree
of risk and uncertainty as dendrites and conductive anodic filaments. Keep
in mind the component suppliers aren’t the high-risk takers of earlier years.
The vast majority of them are also keeping their part numbers for tin-lead,
for a little while anyway. If they offer both choices and the customers select
pure-tin, then they really can’t be held liable for the consequences.
On the opposite side of this tug-of-war are the high-reliability gurus
in military and aerospace. NASA is leading the team and has mounted a formidable
campaign. Although in some cases it may seem that they are employing scare
tactics, nothing else seems to convey their message. With a whopping 0.3%
of the market, these high-rel users have little more than good debate skills
and clever tactics on their side.
So, it seems the fight is almost over. Or is it? The real battle will
now go underground, into the laboratories that perform failure analysis.
The only thing that will reverse this pure-tin tide is solid evidence that
tin whiskers are causing an unacceptable number of field failures.
Hopefully, it won’t be at the cost of any lives. It would be tragic to
repeat history and have to learn Napoleon’s lesson of using pure-tin all
over again. We'll all be
caught with our pants down.
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