I do not know just how clean I need, but pretty dern clean.  But, it gets
potted in silicone, so I just need a way to get it "clean enough" just
before potting.

----- Original Message -----
To: "Multiple recipients of list CHIPDIR-L" <[EMAIL PROTECTED]>
Sent: Friday, February 28, 2003 11:54 AM


> I suspect you do not truly need ultra clean boards.  If you do, you are
> embarking on a long and difficult road. There are testers to measure board
> cleanliness. I suggest you get one and determine your working
requirements.
>
> Zero ion, ultra clean requires a clean room type assembly.  Very difficult
to
> do.  I had a zero ion requirement.  The PCBs had large clear out areas
around
> the critical components.  My biggest problem was both the PCB fab vendor
and the
> assembly vendor insisted on placing dirty test stamps in the clear out
areas in
> violation of the board specifications. The combination of a carbon based
ink in
> a solvent that penetrated the gel coat caused a 100% defect rate. Numerous
lots
> returned to vendor finally convinced them to read the specification before
they
> made the product. It took four months to get my first lot of ultra clean
boards.
>
> Fred Townsend
>
> "Syd Levine (AnaLog)" wrote:
>
> > I am working on a high voltage shunt regulator design where
contamination on
> > the circuit board is causing problems.  What is the best way to scrub or
> > rinse all or most of the ionic contamination off a circuit board?  I
usually
> > use denatured alcohol to remove flux residue, but that is not good
enough in
> > this case.  Any suggestions or wisdom would be much appreciated.
> >
> > Here is a link to the Data Sheet on the little project:
> > www.logwell.com/products/Codatron.PDF
> >
> > Syd H. Levine
> > AnaLog Services, Inc.
> > Phone:  270-276-5671
> > Telefax: 270-276-5588
> > E-mail:  [EMAIL PROTECTED]
> > URL:  www.logwell.com
> >
> > --
> > Author: Syd Levine \(AnaLog\)
> >   INET: [EMAIL PROTECTED]
> >
> > Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
> > San Diego, California        -- Mailing list and web hosting services
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>
> --
> Author: Fred Townsend
>   INET: [EMAIL PROTECTED]
>
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> also send the HELP command for other information (like subscribing).
>


-- 
Author: Syd Levine \(AnaLog\)
  INET: [EMAIL PROTECTED]

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