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November 1999

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Subject:
From:
Hinners Hans Civ WRALC/LYPME <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Tue, 23 Nov 1999 16:37:10 -0000
Content-Type:
text/plain
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text/plain (99 lines)
Chill Rod,

Rudy is a frequent contributor to Tech Net, he's family, he's definitely one
of 'us' and not one of 'them'.  So respectfully, take your flames somewhere
else unless you have something meaningful to contribute to the discussion,
such as what resist stripper you do use instead of Rudy's?

I'm all ears.

Hans


~~~~~~~~
Hans M. Hinners
Materials (& Process!) Engineer
Warner Robins - Air Logistics Center/Avionics Production Division
Manufacturing Branch (LYPME)
380 Second Street, Suite 104    (Building 640)
Robins AFB, GA  31098-1638
912-926-1970 (Voice) 468 - 1970 (DSN)  912-926-926-7164 (Fax)
[log in to unmask]


> -----Original Message-----
> From: Rod Semen [SMTP:[log in to unmask]]
> Sent: Tuesday, November 23, 1999 10:38
> To:   [log in to unmask]
> Subject:      Re: [TN] Tarnish after resist stripping
>
> Hey Rudy,
>
> Next time buy an ad! If this is not thoses blatant advertising post, then
> I
> do not know what is. And by the way I have used your resist stripper.
> It sucked.....
>
>
> >From: Rudy Sedlak <[log in to unmask]>
> >Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>, [log in to unmask]
> >To: [log in to unmask]
> >Subject: [TN] Tarnish after resist stripping
> >Date: Tue, 23 Nov 1999 09:37:28 EST
> >
> >I do love it when someone asks a question that we are real knowledgeable
> >on.
> >Thank you.
> >
> >Tarnish on Copper after stripping is endemic to resist stripping.  It is
> >made
> >much worse by buildup of Copper in the stripping chemistry.  In other
> >words,
> >most strippers will not tarnish when new, but begin to tarnish as they
> are
> >used, and Copper builds in the sump.
> >
> >The problem is cureable by using a  resist stripping chemistry with the
> >proper anti-tarnish in it.  Most resist stripping chemistry has 250 ppm
> of
> >Copper when the stripper is dumped.  It is possible to get resist
> strippers
> >that will not build up more than 30 ppm of Copper for the same number of
> >panels stripped, and average less than 2 false defects per 18" X 24"
> panel.
> >This has a nice added benefit of keeping the Copper in the rinse waters
> so
> >low that they usually do not have to be treated, and can legally be put
> >right
> >down the drain.
> >
> >Many stripper chemistry vendors have resolved this issue by simply going
> to
> >high volume feed and bleed, thus turning the sump over often, and keeping
> >the
> >dissolved Copper levels low.  This is great for the chemistry vendor, but
> >expensive for the PCB fabricator, and not required with the proper
> >anti-tarnish chemistry.
> >
> >As you probably have surmised, we are one of the vendors who can supply
> >resist strippers with the proper anti-tarnish properties.
> >
> >Rudy Sedlak
> >RD Chemical Company
> >[log in to unmask]
>

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