Diganta
We completely disagree re lead-free solders. There was no need for it. Eutectic leaded solder was not a real environmental problem It was a contrived, manufactured issue promoted by special interests that were motivated by greed
You seem to be completely unaware of the reliability problems that lead-free solder has introduced -- tin whiskers, Kirkendall Effect, dissolution of copper from pads, poor wetting, intermetalics, and now cratering! Read the IPC TechNet use group blogs from SMT engineers. Their problems are endless. (I know what most of them think about lead-free solders.)
I now look forward to the virtual elimination of all solder paste, including tin-lead, and of SMT for that matter. The "new" manufacturing paradigm will be embedded chips accessed by copper plated vias similar to the Intel BBUL concept, further developed in the Occam Process. IC density requirements will demand change. Please look at the IC roadmap (ITRS) and the projections for Moore's Law impact out to 2026!! The space required by solder joints on top of their unreliability will consign SMT to nichedom. Check forthcoming SMTA programs. Increasingly people are talking about embedment.
In my opinion, the entire lead-free issue was promoted by the tin miners who created Soldertec. Kay Nimmo did a great job for them. But in the end the tin industry will find that they shot themselves in the foot.
A host of opportunistic consultants jumped on the lead-free bandwagon and helped its
victory. I suspect that the same opportunism may appiy to the counterfeit component issue, at least in part. I am still investigating.
My friends at Cisco and Foxconn (Apple) are not hiding anything when they tell me that counterfeit components are not an issue for them.
By the way, it will be interesting to see how "new" component form factors -- chip passives and KGD actives-- will impact supply chains and counterfeiting. You might look into that potential impact.
--- On Sun, 6/17/12, Diganta Das <[log in to unmask]> wrote:
From: Diganta Das <[log in to unmask]>
Subject: Re: questions
To: "[log in to unmask]" <[log in to unmask]>
Cc: "R Rasmussen" <[log in to unmask]>
Date: Sunday, June 17, 2012, 6:45 PM
Greetings Sir,
I think that the engineering community addressed the lead free
issue quite successfully and now we have established many
alternative solders with detailed knowledge base. Of course, there
was a cost involved, but as a member of the research community, I am
probably biased in recognizing that we know more about the leaded
and lead free solders now than we did earlier and that will help us
in the long run. The problem of counterfeit problem is real and we
need both awareness and solutions - long and short term.
As you have seen, you will find it hard to have any large
commercial company to admit that they have an issue with counterfeit
parts. Some of that has to do with keeping the dirty laundry hidden
but some of it also has to do with the fact that the large
commercial companies do have some in built defenses against the
problem of counterfeit parts.
Regarding my comments about the dollar value of system failures
due to components, those examples are to do with substandard parts
AND parts not being evaluated for use in a particular system. In
some of those cases, the supply chain failure happened at the
component manufacturer level and they had procured and used
substandard material for their products. In some other cases, the
users of the parts did not evaluate the parts properly and
"believed" the flawed qualification results from the part
manufacturers. My point is that counterfeit parts is only
occasional results from supply chain failure and such failures can
result in various types of failures.
The part that made it to space application (not to space - the
part went into the pyrotechnic system in the astronauts suit in case
they need to bail and needed to be rescued) was clearly a case of
dropping the ball on basic quality control. The manufacturers would
have caught the problem with BOTH the supplier AND the specific
part. As you can see on the slides, the bad part had SIGNIFICANT
difference with the real part AND there was a GIDEP alert out on
that part. It was a sloppy job.
Diganta
On 6/13/2012 12:08 PM, Harvey Miller wrote:
Diganta
As a skeptic who fought lead-free solder as a
"non-solution to a non-problem", I m trying to understand
the real problem of counterfeit components. Your
presentation at the H.O.S.T panel in San Francisco on
June 4, 2012 was notable for stating that the answer is
not inspection but is supply chain control. That has been
confirmed in discussion with a friend at Cisco. They do
not perceive counterfeit components to be a problem. I
will also be pursuing that question with a friend who was
CTO at Foxconn, for their and Apple's view.
Yet in your presentation you quantified the dollar impact
of component counterfeiting in specific cases, citing IC
devices that caused system failures. Why did the supply
chain control model not work in those cases? May I have
links that will explain those cases?
Also you showed a counterfeit component that found its way
to Space. What accounts for that one?
In the selling of lead-free solder there were many
opportunists that contributed to a very negative outcome
for the electronics industry. I feel that there may be an
analogous situation with counterfeit components.
--
*********************************************
Dr. Diganta Das
Center for Advanced Life Cycle Engineering (CALCE)
Rm 1103, Engineering Laboratory Building
University of Maryland
College Park, MD 20742
(301) 405 7770
(301) 314 9269 and (775) 218 5209 (Fax)
http://www.calce.umd.edu
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