TECHNET Archives

November 1999

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Rod Semen <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Tue, 23 Nov 1999 07:37:42 PST
Content-Type:
text/plain
Parts/Attachments:
text/plain (81 lines)
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]
>
>##############################################################
>TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
>##############################################################
>To subscribe/unsubscribe, send a message to [log in to unmask] with following
>text in
>the body:
>To subscribe:   SUBSCRIBE TECHNET <your full name>
>To unsubscribe:   SIGNOFF TECHNET
>##############################################################
>Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
>additional
>information.
>If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
>847-509-9700 ext.5365
>##############################################################

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

ATOM RSS1 RSS2