In a message dated 96-06-12 18:22:02 EDT, you write:

>What would be a reliable test method for selling the 
>     No-Clean/Low-Residue flux concept to Mil Customers.  Is 
>     Ionograph testing best?  Could I get some replys from some 
>     of you folks who have jumped this hurdle.  Looking for some 
>     suggestions.  Thanks in advance for the help.

Mr. Hollandsworth,

This is an easy question to ask, but a difficult one to answer, simply
because there are so many variables to consider.  I'll give it a shot though.
 

To answer your first question, my opinion is No.  Most low residue fluxes
have weak organic acid (WOA) activators.  These activators are benign
insulators on a board surface, but become electrically conductive when
extracted into an isopropanol / water solution.  You tend to get high
readings on an Ionograph or similar instruments.  To the uninitiated, the
high levels are cause for grave concern, and will do more damage than
assistance.  The amount of applied flux is generally proportional (roughly)
to the instrument response.  I would prefer ion chromatography (IPC TM-650,
method 2.3.28).  It shows what ionic species are present.  It is more
expensive than an Omegameter run, but you get much more relevent data.  I
don't want this to turn into a running commercial for IC.  If anyone wants to
know more about this science, call me.

The issue of how to go about convincing a military customer depends on a
number of factors:
How open to change are they?
What kinds of data do they need to see?
Which carries more weight, engineering data or contractual obligations?
What is their general understanding of the issues involved?
How open are they to J-STD-001?

I have worked with numerous customers who have qualified a no-clean program
for military applications.  There is no one set way to go about it.  Some
have gone the path of least resistance - qualifying to Appendix A and C of
MIL-STD-2000A, odd as that document may be.  With that qual data in place,
they can use the new process, no questions asked (theoretically).  Others
have gone the route of qualifying to J-STD-001A, Appendix D and F.  This has
been of lower cost, but requires greater customer buy-in.  Others have gone
the route of doing a very thorough test battery, including ROSE, IC, HPLC,
SIR, etc., and challenged the customer to find something wrong with the
approach.  

If you would like to answer the questions posed above, I might be able to
give you a better response.

If you would like a more detailed discussion of some of the issues involved,
I have authored a rather odd document called "The Laymans Guide to Qualifying
to MIL-STD-2000A".  The title was originally "The Schmucks Guide...." but
Dave Bergman informed me that there were some rather vulgar Yiddish
translations of Schmuck, so it changed.  I think Dave has posted the document
to the IPC FTP site.  Those who have reviewed the guide before have said it
gives food for thought.

If all else fails, give me a call.  I discuss the issues a few times a week.

Doug Pauls
Contamination Studies Labs
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(317) 457-8095