Mike- In a previous life we had a black sludge build up in an ammoniacal etch. Played havoc with the chloride levels and reduced etch performance. Turned out it was zinc and a few other metals from the double treat foil we used. Just wondering if you had it analyzed, don't now what type of foil your using or if it could be the same type of situation. At 07:26 12/16/1999 -0800, you wrote: >We recently installed a new DES line using cupric chloride with sodium >chlorate regeneration. We have been experiencing a blue/black residue that >coats the etch filters and seems to find it's way into the spray nozzles >etc. etc. We beat the fluoride theory and seal degradation to death and >have found nothing substantial. I have been told that others have >experienced this problem and have attributed it to various causes such as >developer drag-in, anti-foam contamination and leaching of dryfilm organics. >I've also heard of others that have retrofitted carbon filtering systems on >to their etchant recirculation pumps. I should note that this is brand new >"high end" equipment with plenty of water rinse stations and blow-off >modules. Does anyone have any experiences they would care to share? Thanks >in advance. > >Mike Bailey >Director of Engineering >McCurdy Circuits Inc. >4900 E. Hunter Ave. >Anaheim, CA 92870 >Phone: 714 507-4900 Ext 253 >FAX: 714 507-4911 >e-mail: [log in to unmask] <mailto:[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 >############################################################## > Ian A. McMillan Engineer Herco Technology 13330 Evening Creek Dr. North San Diego Ca. 92128 Ph# (858) 679-2800 Fax# (858) 679-7565 ############################################################## 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 ##############################################################