Edward, regarding your question about DMAB reduced oxide; yes, it certainly does make the oxide conductive - that is why it is important to insure that your copper content of your microetch is low so that it does not leave copper sulfate crystals on the surface, and that your pre-dip bath is not "dirty" - full of copper hydroxide - because that can deposit on the surface as well. The end result is shorts, and this has been a fairly common problem at a variety of PWB shops. Regards, Fred J. >>> "Eltek Ltd. - Process Engineering" <[log in to unmask]> 01/18/98 01:56am >>> Hi Technetters ! Some time ago I tried to test electrical conductivity of the reduced black oxide : I placed a piece of conducting rubber on reduced black oxide area and measured conductivity between this area and the upper part of the rubber .The innerlayer was rinsed in DI water and dryied at 95 centigrade to take away any moisture . The purpose of the rubber was to avoid scraches on black oxide . I was suprised , but it was conducting . Does anyone has explaination what is the mechanism ? I would expect , that dry crystals of cupric and cuprous oxide should not conduct . One of my friends told me , that one of crystal form of cuprous oxide is conducting . Best regards Edward Szpruch Eltek Ltd - Israel Tel 972 3 9395050 Fax 972 3 9309581 E-mail : [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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ############################################################## ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################