If we look at the usage of "mission critical" applications what sort of
product are we talking about?
Consider, most (if not all) interconnections within aircraft (lets look at
the aerospace biz f'rinstance) are terminated using crimped connectors and
are in a "don't care" catagory with respect to environmental policy. Things
like engine controllers, LVDT controllers etc. in the likes of Boeing
aircraft represent a very small percentage of the overall mass or volume
(assemblies weighing 2Kg or less). None of these assemblies are what one
would term "special" requiring anything other than normal (for aerospace)
7-9 sigma controls during design/construction. None of the individual
components will be susceptable to even the worst case reflow temperatures
quoted as all of the components chosen are DEF STAN 883C or better assuring
working temperature of -55 to +125 deg C and in most cases immunity to high
ambient/process temperatures (can you imagine what would happen to an engine
controller populated with plastic devices strapped to an RB211 engine whilst
waiting for takeoff clearance at Delhi airport with 44 deg C ambient and
engine cowlings at 350 deg C+ above ambient and an assembly generating at
least 80 watts of heat internally). PCBs are commonly based around aluminium
laminated epoxy/fiber rather than FR4 so are again in the "don't care"
catagory regards both environmental and process issues. We then come down to
the reliability of the electronic assemblies. If, for example, we take a
standard process change like a component end of life. It commonly takes 5
years and upwards for the change to go from the planning, through proving
and eventualy to the production for this change. So in this we can see that
the "lead free" process changes will not happen until well after the 2004
date for implementation owing to the dramatic impact (the 5 year plan quoted
on occaision within the aerospace biz being best case for a simple change)
upon the qualification/ proving required.
Perhaps this model is not the best.
What then do we consider "mission critical". Space flight (including
satellites)? submarines and other toys of destruction? hospital equipment?
For hospital equipment (the only "mission critical" application that I can
think of note or merit here) we find that assemblies are not overly complex
(when compared to something like a TV studio), readily ammenable to
redesign, do not have prohibitively long qualification plans and are placed
within a marketplace with, historically, a high markup. This all lends
itself to an easier process change and traditionally has the funding for any
product respin.
I for one will not greive if the trident missile programme, submarines,
tanks etc. have to be scrapped because suitable alloys can not be found.
Where next then? If anyone can suggest a "mission critical" application that
does not involve prolonged product design, proving and testing then I
believe we would have grounds for concern.
For our part we have always subscribed to ALT testing including temperature
cycling, vibration and thermal shock as part of our qualification
procedures. This is also backed by investigations by process engineers
component engineers and statistical analysis of production efficiency. This
is not always possible and, in many ways, is dependant upon the resource
available to the process owner but much of the data gleaned from our
investigations will be fed back into the knowledge pool via component
suppliers, forums and the inevitable migration of staff through related
industries.
What is left is, to me, an apparent lack of coordination regards any proving
of the lead free process and other environmental initiatives. It seems to be
politically expedient to raise issues and propose corrective actions to
counter the last three hundred years of environmental suicide but little
thought has been proposed regards leadership and funding of research and
implementation. Some efforts are being made at a local level by the likes of
NPL, IPC and ITRI and indeed the forums are now starting to percolate
through the scientific and industrial communities. What is required is
positive and definitive support by the legislative bodies on a world wide
basis so that the improvement of our living conditions does not become a
criteria by which individual companies increase sales and profit margins on
so called "green" gimmicks.
My soap box is beyond repair, anyone got a replacement?
Regards,
Martin.
-----Original Message-----
From: David Hillman [mailto:[log in to unmask]]
Sent: 18 August 1999 15:28
To: [log in to unmask]
Subject: Re: [LF] Lead Usage in Electronics
Hi Bernard! The major issue I have with the draft EC directive is the
timetable! Due to the lack of sufficient evidence of a lead-free
replacement for the mission critical applications, it may take longer than
5 years to change our current lead/tin based processes and support
functions. Many folks draw comparisons of the proposed lead ban to the CFC
phase out but there were proven CFC replacements in that situation. The
womb-to-tomb proposition will be a forcing function just like the added tax
on CFC's - it will keep folks from being complacent which is good. You and
I are on the same page!
Dave Hillman
Rockwell Collins
[log in to unmask]
Bernard Mulcahy <[log in to unmask]> on 08/18/99 08:13:38 AM
Please respond to "Leadfree Electronics Assembly E-Mail Forum."
<[log in to unmask]>; Please respond to Bernard Mulcahy
<[log in to unmask]>
To: [log in to unmask]
cc:
Subject: Re: [LF] Lead Usage in Electronics
Hi David-
the proactive approach you are talking about is in essence what the draft
EC
directive proposes. It does propose a total ban on lead by the year 2004 ,
but more importantly it the fact that it is a Waste Management directive.
Most people seem to have focused on the proposal to ban lead and its
consequences, but more importantly the producer is responsible 'womb to
tomb' for product. Indeed current producers will also be responsible for
all
recycling - even of product produced by now non producing or closed
companies.
I feel if this part of the proposal goes ahead and that if the lead issue
is
pushed out on 'critical electronics' that this will have the greatest
benefit to the environment and society. However the larger producers here
in
Europe seem to be reluctant to take responsibility for the waste and are
predicting a collapse of electronics production in Europe. My own feeling
would be that we as an industry have to take steps on a global scale and in
this way no one region's industry will be adversely affected.
Regards,
Bernard Mulcahy
Manufacturing Support.
[log in to unmask]
> -----Original Message-----
> From: David Hillman [SMTP:[log in to unmask]]
> Sent: Wednesday, August 18, 1999 2:01 PM
> To: [log in to unmask]
> Subject: Re: [LF] Lead Usage in Electronics
>
> Hi Alan - Now there's a proactive approach! If an exemption was granted
> for
> the mission critical applications but with the stipulation that the
> producer is responsible for the product womb-to-tomb then its a win-win
> situation. The producer has time to find an acceptable alternative but
> also
> is being given incentive to eliminate the lead containing alloy. Good
> idea.
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
>
>
>
> Alan Rae <[log in to unmask]> on 08/18/99 07:27:46 AM
>
> Please respond to "Leadfree Electronics Assembly E-Mail Forum."
> <[log in to unmask]>; Please respond to [log in to unmask]
>
> To: [log in to unmask]
> cc:
> Subject: Re: [LF] Lead Usage in Electronics
>
>
>
>
> Dave, you're absolutely right. There are two areas, critical and
> non-critical,
> however you want to define them.
>
> Remember though, joking apart, industrial non-assembly solders are used
in
> mission-critical automotive systems such as wiring harnesses that are a
> tad
> more
> demanding than stained glass.
>
> Maybe an approach for IPC, PCIF etc. is to lobby for exemptions in
clearly
> defined mission-critical areas where takeback, dismantling and recycling
> rather
> than a switch to lead-free solder is the best option. The volume will be
> more
> manageable and I believe a mechanism/precedent is already established in
> the EC
> ELV Draft Directive where specific labeled components can be removed from
> vehicles according to manufacturers' manuals at end of life? We're going
> to
> have to take these things back anyway in the future.
>
> Enjoy your breakfast!
>
> Alan Rae
> Specialty & Industrial Materials
> Cookson Electronics Division
> 508 541 5843
> ---------------------- Forwarded by Alan Rae/CooksonUS/Cookson on
08/18/99
> 08:08
> AM ---------------------------
>
>
> [log in to unmask] on 08/18/99 07:40:56 AM
>
> To: "Leadfree Electronics Assembly E-Mail Forum." <[log in to unmask]>,
> [log in to unmask]
> cc:
> Fax to:
> Subject: Re: [LF] Lead Usage in Electronics
>
>
>
>
>
>
> Good morning! Alan makes some good points but I believe leaves out the
> heart of the matter. Yes, proven lead-free solder alloys exist for
stained
> glass windows, plumbing, and a host of other products. Very shortly we
> will
> see lead-free solder alloys for TVs, VCRs, and other consumer electronics
> that will be very reliable. However, there is a pretty big difference in
> whether I can listen to my favorite CD or have toast pop out of my
toaster
> in comparison to my automobile running correctly or the plane I happen to
> be flying in stay in the sky. The lead-free discussion needs to always
> contain two areas of concern - industry electronics and high performance
> electronics (that's stealing a couple of definitions from IPC). There are
> electronic products we require/expect a much higher performance level -
> medical, auto, system critical types of devices. If the technical
> community
> is given sufficient time and resources some lead-free solder solutions
> will
> be found for the high performance products too - but too lump the
> industrial and high performance into any statement that lead-free alloys
> are available is misleading and confusing. Well enough soap boxing and
> time
> get a Coke for breakfast - please keep the flames to a low roar.
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
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IPCWorks -October 25-28 featuring an International Summit on Lead-Free
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For technical support contact Gayatri Sardeshpande [log in to unmask] or
847-790-5365.
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To subscribe/unsubscribe, send a message to [log in to unmask]
with following text in the body:
To subscribe: SUBSCRIBE Leadfree <your full name>
To unsubscribe: SIGNOFF Leadfree
################################################################
IPCWorks -October 25-28 featuring an International Summit on Lead-Free Electronic
Assemblies.
Please visit IPC's Center for Lead-Free Electronics Assembly
(http://www.leadfree.org ) for additional information.
For technical support contact Gayatri Sardeshpande [log in to unmask] or 847-790-5365.
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