Subject:                               Time:12:45 PM
  OFFICE MEMO          Defluxing complex electronic assys.    Date:4/26/95
Subject: Defluxing complex electronic assemblies

Are users successfully replacing Freon TMS vapor degreasers used for
defluxing complex electronic assemblies, i.e. those with hard-to-rinse
capillary spaces?  

Specifically, I am dealing with a 20 year old military design, a hinged stack
of through-hole PWB's hard wired together via a cable assembly which
incorporates shrink sleeving, solder sleeves and insulated stranded wire. 
The construction contains many thermoplastics, labels, wire tags,
polyurethane elastomer connector potting and neoprene grommets.  The assembly
cannot be heated above 150#161#F.

I am reluctant to use the low vapor pressure semi-aqueous cleaners  or
saponifiers because of rinsing problems.  Do users have experience with
either of these approaches in a similar application?  

I am looking at a batch process using either IPA or AK225.  Any other
suggestions?  The flammability of IPA is a drawback.  The cost, lack of
industry history, and eventual phase out of AK225 are drawbacks. What
experience has anyone had using these chemicals in bulk?  What equipment (in
addition to S&K, Jetclean & ReEntry/Eccolink) is on the market that will
handle IPA?

Any information from users would be sincerely appreciated.

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