Hi, Jean-Paul,
Apologies for the delay in replying the last week has been truly manic.
I agree with you, the reliability of the product for its intended use is
what matters. It is very apparent though that in a lot of applications a
"drop in" is probably not going to work without some engineering forethought
acting as a "reliability enabler". I have put some papers on the web site
which look at aspects of "wait and see" in terms of reliability I have now
I suppose, to come clean and air my ideas on reliability.
I feel that in many areas groups like the IPC lead free-forum are in many
areas, "too expert".
For instance you yourself, Werner, many others on this forum have a huge
amount of experience in the materials properties of lead free solders; you
have had to "go there" because of the legislation.
Consider though the lead free listing for IPC. I just had an advice through
that the total distribution list of the IPC lead-free link list is 762
people. Which I am sure no one would argue does not represent the whole of
the electronics industry, most of which is being directly impacted by lead
free, and all of which is being impacted by the changes in components
materials due to it.
My point is that reliability comes about as a result of the materials and
components chosen to go into an assembly, the design of that assembly, and
the processing that it is put through during the course of its manufacture.
All of these things can be assessed, controlled and understood with
experience.
Unfortunately, I believe that the majority of the industry is on a virtual
100% learning curve with a process with which they have no experience at the
present time. We should therefore expect expect fall out due to that reason
as well as in designs where the replacement was not a "drop in" for the
original application.
I am trying at the present time to get some of the manufacturers that I know
are having issues to report this - but as you say it is difficult, - who
wants to admit their product is "out of control".
I do however have a plan................8-)
To enable information to be shared anonymously, I am going to arrange an
anonymous log-in FTP site on the http://wwww.rohsusa.com web site over the
next few days.
This will enable photos to be shared along with problem descriptions without
any stigma attached to "company xyz".
This is indeed a very emotive issue. Take last week, there was a press
release went out to the media stating that T-Mobile and Cingular had removed
the Motorola RAZR telephones from their stores and that Motorola had done a
batch recall. Here is the original headline that came through the news
channel:
=========================================================================
Cingular, T-Mobile halt Razr sales due to glitch
Motorola said only a limited number of phones were affected and the problem
would have no impact on its financial results. The Razr, lauded for its thin
design, was first sold in late 2004 and is still a key product for Motorola.
=========================================================================
Well guess what, if you had searched on that same link on Reuters and CNN
etc just an hour or so later you would find that the story was "pulled" the
banner is still there on both services but the story is mysteriously
"unavailable". And no I am not saying it was due to a lead free process just
pointing out that companies will go to extreme lengths not to have their
issues aired in public.
I will circulate the list with the anonymous ftp upload site once I have it
set up securely. I do not believe it will bring instant responses, but it
will be there when needed, you have to do what you can - right? Hope you all
like the additions and changes to the web site.
Kind regards,
John
http://www.rohsusa.com
http://www.rohsasia.com
http://www.rohseurope.com
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of [log in to unmask]
Sent: Sunday, April 30, 2006 3:11 PM
To: [log in to unmask]
Subject: Re: [LF] Is lead removal really necessary in solders?
Hello John,
Interesting site at: _http://www.rohsusa.com_ (http://www.rohsusa.com)
Lots of work there! I am looking forward to looking at the hard data and
references, especially with respect to lead-free failures.
On the main page, one bullet (# 2) says:
"2) Expert opinion says that reliability WILL be an issue and that the
replacements for leaded solder are simply not as reliable as their leaded
predecessors. As this site grows, I will be providing links and examples
of
failures if/as they occur. If you have any examples, please email me. "
I am interested in more background information on the above bullet:
1) Who are those experts and where can we find their opinions? where has
the
supporting data been published?
I have quite a bit of accelerated test data, but that does not tell me
anything about product reliability in the field. I come from the
perspective that
reliability is the ability of a product not to fail, i.e. the ability to
survive (up to an acceptable failure level) in a given application and for
a
given period of time (i.e. the targeted design life). So, I am not worried
if a
particular lead-free alloy is less reliable than SnPb in a given
application,
as long as the product reliability requirements are met.
2) Are those same experts saying that all non-leaded solders are
unreliable?
if not, which ones are deemed reliable, and which ones are not?
As you know, eutectic SnBi has been used for a long time - successfully and
for purely technical reasons in applications of choice- well before the
lead-free debate took place.
Eutectic SnAg has been around for a long time aswell and has seen a similar
success in high-temperature applications. However, as discussed below, there
has been both SnAg and SnPb failures in the field.
3) About "examples of failures", I am also looking forward to seeing those
when they become available. I assume you are referring to field failures
here. For completeness, can you also include field failures of SnPb
assemblies?
There has been quite a few, but overall a very small proportion, over the
years.
The tough part about all of this is that field failures are not talked
about
much, although much can be learned from them. I have had the opportunity
to testify in court about SnPb failures on products manufactured in high
volume. Those are usually due to poor workmanship and/or a lack of or/
poor
design-for-reliability. I can't give specifics here because of
confidentiality
agreements, so don't take my word for it. I suspect that others - including
some among the experts you are referring to - can relate similar stories.
I
have not heard of SAC field failures yet. If you have, I would be
interested in
hearing more about it and your web page is definitely a good place to
illustrate those lead-free solder failures. I had two cases of SnAg field
failures
some time ago, well before the July 01, 2006 deadline loomed on the
horizon;
the root cause was inadequate design-for-reliability.
My view is that there are applications (usually low or high temperature
apps.) where lead-free solders were selected for purely technical reasons
and
rendered good services. Also, having witnessed a couple of SnPb failures
in the
field never worried me. There were good technical reasons for it and I
would not generalize about SnPb being reliable, or not (it's all product
and
application dependent). Similarly, I can't generalize and make blanket
statements about lead-free solders.
Looking forward to learning more about the lack-of-reliability and failures
of lead-free solders that are referred to in bullet # 2 of your main page.
With best regards,
Jean-Paul
________________________________________________________________
In a message dated 4/26/2006 12:08:49 P.M. Eastern Standard Time,
[log in to unmask] writes:
Good morning electronics industry!
For all of those people out there who cannot understand WHY we are
removing the lead in solders I have put up a web site as both a
discussion as well as an informational forum.
It makes some points and provides a feedback vehicle for those among us
who feel that it was not necessary and actually may be environmentally
detrimental.
And whether you agree with it or not please take the time to read
through it - the feedback is valued. If you like it, pass this email
along to your Colleagues.
Here is the link:
http://www.rohsusa.com
Kind regards,
John
Quote of the month:
"Success is the sum of details", Harvey S. Firestone.
_______________________________________________
Jean-Paul Clech
EPSI Inc., P.O. Box 1522, Montclair, NJ 07042, USA
tel.:+1 (973)746-3796, fax: +1 (973)655-0815
_http://www.jpclech.com_ (http://www.jpclech.com/)
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