[tinwhiskers] Re: R: Re: ACE Develops Lead Tinning System
- From: "Bob Landman" <rlandman@xxxxxxxxxxxxxxxxx>
- To: <tinwhiskers@xxxxxxxxxxxxx>
- Date: Fri, 6 Jun 2008 13:42:23 -0400
Some here have asked: "have whiskers have grown and caused failures after
"no-lead RoHS" was enacted?"
Let me reverse the question; why do you think the absence of lead (RoHS) in tin
plating has stopped whisker growth?
What would suggest to you that you draw that conclusion? Has passing that EU
law changed the science? Has the universe complied with RoHS?
I do not think so.
NASA says that not all whisker-induced failures can be identified. Very few
analysts correctly identify whisker-induced problems. A professional failure
analysis can run between $300 and $3,000 per job. Almost no broken commercial
equipment is ever put through any such analysis; rather, the failed unit is
junked or refurbished without any assignment of the fault. It is
characteristically only equipment used in tasks of high importance that gets
any analytic attention. And, sadly, only a very few analysts are able to
correctly recognize whisker induced problems!
Does commercial-grade equipment have this problem? It is typically only the
military and space communities that carry out the analysis that is necessary to
locate the source of the damage. And then, only a few of the folks making these
analyses are perceptive as to the real cause. Not all cases of whisker-induced
failures are reported!
NASA has logged, in 5 years, 3 to 5 reports a month of tin whisker infestation
that required urgent help. Note that only a very few have allowed NASA to
document their problems in detail or share results publicly. Fear of lost
sales, warranty claims, punitive damages, injuries, embarrassment and no desire
to share solutions to problems with competitors.
For the last five years or so, NASA is logging from three to five calls a month
from folks who have spoken with them about tin-whisker infestations at their
companies ? infestations so bad that urgent attention was needed and eventually
produced a correct identification, often with our help ? and then these folks
have requested confidentiality. To a good approximation, NO ONE has allowed
NASA to log their problem(s) in an explicit manner. Their reasons are clear
enough: these include fear that sales will drop, and fear of a run of warranty
claims and even claims for damages and injuries, and fear of embarrassment at
being caught in bad practices. So, to protect themselves, they forbid their
problem from being listed. Sometimes, the argument is that: "OK, now we have
learned about this; darned if we will share this learning with our competitors:
let them figure out why this stuff is failing!
It is the "problem of the commons".
There is the story of a room filled with people, and also a dead stinking
horse. Each person has a personal reason for silence, and so no one mentions
the rotting carcass. Thus, the group does not work together to improve the
living conditions, and soon all succumb to the poisonous gases and corruption.
NASA estimate of the problem
?The hundreds of cases we have documented scale to roughly a few million to a
few hundred million cases of whiskering problems over the last fifty years ---
this seems about right to me?, so says Dr. Henning Leidecker at NASA's Goddard
Space Flight Center. He suspects that about 3% to 30% of electronics systems
that are using pure tin plating are growing whiskers, and that about 0.5% to 5%
of the total are having shorts caused by these whiskers, and that about 0.005%
to 0.5% of the total are having the cause of these shorts correctly identified,
and then about 0.000,01% to 0.01% of the total are being publicly named. He
goes on to say that the hundreds of cases they have documented scale to roughly
a few million to a few hundred million cases of whiskering problems over the
last fifty years; this seems about right to him.
But the public perception is that there are only a few cases, and that these
have happened "to other folks".
Bob Landman
H&L Instruments,LLC
From: tinwhiskers-bounce@xxxxxxxxxxxxx
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of Gabriele Sala
Sent: Thursday, June 05, 2008 6:42 PM
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] R: Re: ACE Develops Lead Tinning System
I have never seen a Mom publicize when her kids have air infested with lice
(louses ? pidocchi ? ), Who have them, they keep them as a secret !!! L.
NASA has nothing to loose by saying the true. Small Companies could loose the
little remaining job ( after Globalization plus RoHS) if they tell the true
about whiskers growing on their electronic assemblies.
Best Regards
Gabriele Sala
-----Messaggio originale-----
Da: tinwhiskers-bounce@xxxxxxxxxxxxx [mailto:tinwhiskers-bounce@xxxxxxxxxxxxx]
Per conto di Niki Steenkamp
Inviato: mercoledì 4 giugno 2008 10.18
A: tinwhiskers@xxxxxxxxxxxxx
Oggetto: [tinwhiskers] Re: ACE Develops Lead Tinning System
Hi,
I have only been following this list for a month or so, but I was wondering if
there has been any tin-whisker failure documented that can be attributed to
RoHS. All the NASA and other tin-whisker failure reports I have seen are from
the pre-RoHS era (which goes to show that even without RoHS we had problems!).
Most ?modern? papers demonstrate whisker growth in lab environments. Although
all of this is relevant and should at the very least blink red warning lights
in our minds, I do not think anybody will really sit up and take notice until
things start failing AND it can be proven that it is due to RoHS. It is sad,
but that is how humans work. And with so many Pb-free systems in the field by
now, failures should start occurring. Maybe we should focus not on waiting
until the first airplane falls form the sky, but rather look for tin-whisker
related problems in everyday electronics of which there are many more potential
candidates. Build up a solid database of verifyable RoHS failures and we will
have undeniable proof. I was recently in a SMD manufacturing seminar where a
fairly well respected international expert stated that he does not believe tin
whiskers are a reality in real life and that they occur only in labs. Scary.
Regards,
Niki Steenkamp
From: tinwhiskers-bounce@xxxxxxxxxxxxx
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of John Lau Hon-Shing
Sent: 04 June 2008 01:35 AM
To: Engelmaier@xxxxxxx; tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: ACE Develops Lead Tinning System
Dear Werner:
As I said I totally agreed with you that it is not ACE's fault/problem. When I
was at Agilent, we also did re-balling to replace the SAC balls to SnPb balls.
Even all of our products are out of the scope of EU RoHS, however, all the DRAM
(in PBGA) already concerted to lead-free and our products need more than 20
years of lives.
By the way, I just told Michelle this morning that I cannot go to London this
time and asked her to give all my registrants to you. Please talk to her!
Thanks & Best Wishes!
John H. Lau
Microsystems, Modules & Components Laboratory
Institute of Microelectronics (IME)
11 Science Park Road
Singapore Science Park II
Singapore 117685
TEL:(65)6770-5424; lauhs@xxxxxxxxxxxxxxxxx
From: Engelmaier@xxxxxxx [mailto:Engelmaier@xxxxxxx]
Sent: Wednesday, June 04, 2008 07:16 AM
To: John Lau Hon-Shing; tinwhiskers@xxxxxxxxxxxxx
Subject: Re: [tinwhiskers] Re: ACE Develops Lead Tinning System
Hi John,
In your world?that is mass-produced consumer products, the pragmatic view has
to be that the Pb-ban is a fact of life. And with these products it is a fact
of life.
But what do I tell a client with a 24-layer 250-mil thick PCB with 4 power- and
ground-layers who has to put BGAs on it.
They do not fall under RoHS.
They do not sell in the EU, China, Japan, Korea, etc.
What I tell them is to re-ball to Sn37 AND use vapor phase?works like a charm.
That is why people develop these systems to re-coat, re-ball, etc., because
there is a market for it, that cannot be met with Pb-free solders [they do not
want to go the Bi- or In-route].
See you in London at NEW.
Werner
Future workshops:
Reliability Issues with Lead-Free Soldering Processes, June 17, London
Interconnect Failures and Design for Reliability for PCB PTHs, June 17, London
Pb-Free Soldering Processes?Survival, Quality, Reliability, August 18, Orlando
Reliability Issues with Lead-Free Soldering Processes, September 22, Schaumburg
Failure Mode and Root Cause Analyses Reliability (Fatigue, Brittle Fracture,
ENIG), September 22, Schaumburg
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