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 ##############################################################