I have a situation where there has been a small fire in a data center.

There was no water involved in quenching the fire.
*So how was the fire quenched?  Halon?  CO2?  Chemicals?

The equipment manufacturers are considering walking away from their
maintenance agreement citing contamination levels in excess of 1.56 ug/cm2
based on ANSI J-STD-001 rev. B

They have provided an ionograph reading of 3.6ug/cm2 of NaCL equivalent on
a circuit board as evidence and various swabs of exterior surfaces on
equipment cases - most in excess of this standard.

*Wow, talk about smoke and mirrors (pun intended).  These figures refer to
a circuit assembly after it has been manufactured, not after it has been
through a fire.  It is a completely bogus use of the figure.  Of course,
the test itself is bogus, but thats another issue....

We have used IPC-TM-650  2.3.28 - Ionic analysis of circuit boards, ion
chromotography method readings and recorded:

        Uninvolved Circuit board:         0.25 Chloride ug/cm2

        Involved Circuit Board:                0.28 Chloride ug/ cm2

The J-STD is a post solder cleanliness standard. It is being used
inappropriately as a benchmark in situations it was never designed for and
for a methodology that has an ionic extraction yield greatly more efficient
than the methodology cited in the standard.

q1)  Can anyone provide me with references to reliabilty studies of
electronic equipment contaminated by fire combustion products.

*It depends on what you consider to be a study.  When I was at CSL, we did
some analyses of burned boards and other boards near fires, trying to
determine the source.  We found that a fire tends to deposit chloride
everywhere, and if the boards themselves burn, you get huge levels of
bromide.  Sulfate is also usually very high.  Fortunately, unless the
boards were heat damaged, you can probably run them through a simple
rinsing (a run through the Omegameter would work) and drying process to get
off the surface contamination.   I think we published it as one of our
Process Rx case studies.  Give CSL a call a 765-457-8095 and they may be
able to give you more information.

q2) Any thoughts and insights into the appropriate/inappropriate use of the
J-STD under these circumstances.

*The use of the J-STD is inappropriate here, unless the contention is that
your boards were dirty to start with and that caused the fire.  But it does
not sound like that from the stating of the problem.  I am not aware of ANY
IPC spec which would apply in this case.

q3) Why am I finding such a great discrepancy in the reported results.

*Because you may not be getting an apples to apples comparison.  To my
knowledge, only CSL and Delco have done much work setting standards for
cleanliness by ion chromatography.  Most vendors that have to service their
own equipment pretty much figure that units will come back from  the field
contaminated and will need cleaning, so I doubt you will find any specs on
it.  In your particular situation, you will probably have to rely on
experienced consultants in the area, rather than specifications.

Doug Pauls
Rockwell Collins

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------