]]]]]]]]]]]]]]]]         OZONE PANIC         [[[[[[[[[[[[[[[[[[[[
     Board-Cleaning Fluids May Force Design Changes     
                        Stephen A. Magnus
                          Staff Editor

  From EDN News Edition [Newton, MA], 9 February 1989, p. 1:2

          [Kindly uploaded by Freeman 10602PANC]

[Some of the not-widely-publicized consequences of a ban on CFCs
are mentioned in this article. Note that the EPA, in its Division
of Global Change, has an interest in hysterical predictions of an
imminent end of the world.  The article states that `[s]cientists
believe they now have strong evidence that CFCs  damage the ozone
layer ...', but readers of AtE know better.]

   The use of substances other that chlorofluorocarbons (CFCs) to
clean printed-wiring assemblies may have serious and far-reaching
repercussions for design engineers,  according to several members
of a group exploring alternative cleaning agents. ...
   The  group  [representatives from  the  Department  of Defense
(DoD), EPA's  Division of  Global Change, industry] is  exploring
alternatives to  CFC-113, the  major component  of a commercially
popular and  DoD-specified cleaning solvent  for assemblies.  The
production of CFC-113  and other CFCs  must be reduced  by 70% by
1998,  according  to  the  terms  of  the  International Montreal
Protocol, signed on  behalf of the US  by former President Ronald
Reagan in September 1988.
..[I]f  certain aqueous  cleaning fluids  are  used in  place of
CFC-113,  a higher  standoff may  be  required for  components on
boards.  Such fluids have higher surface tension than CFC-113 ...
which  may  prevent  them  from  cleaning  as  effectively  under
components close to the board.
   Designers may need to consider  whether the boards they design
can withstand  high-pressure sprays ....   [A]queous cleaners may
be blown  at boards  at pressures as  high as  100 to  200 psi in
order to clean in tight spaces effectively.
   Fragile leads are unlikely  to withstand such blowing pressure
.. so a more sturdy package may be necessary. ...

   [M]any  aspects  of  component manufacturing  may  need  to be
reevaluated, including plastics, sealants, gaskets, and markings.
The  new  cleaning agents  will  probably be  more  abrasive than
CFC-113 to the materials of the components, the solder masks, and
marking inks ...
   Designers  may, for  example, have  to restrict  themselves to
using  ceramic  or a  limited  choice of  plastics  for component
material.  Furthermore, these restrictions  may not allow maximum
electrical  performance   and  minimum  thermal   stress  in  the
completed assembly ...

[Sysop's note: The buffoon here is not the author of the article, 
who is only reporting the truth, but the opportunists who are rid-
ing the sensationalist calamity wave to get themselves publicity 
and may be a little funding for something with VERY flimsy scienti-
fic evidence.]

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