Rod: You might try this, it requires a little more work and an AA, but it will tell you if the chromate is completely removed from your work. Providing that the conversion coating is chromate based. Check with your supplier. Take a 2x2,3x3, whatever, copper laminate coupon sample. One uncleaned sample laminate and one cleaned laminate, two 30 to 50 percent nitric solution in beakers that the coupons will fit into. Immerse each coupon into a beaker for about a minute. Take the nitric solution and analyze for chrome. Good Luck, Michael Newman Process Engineer "X" Circuits, Inc. >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] No Chromate Test, but an alternate >Date: Wed, 22 Sep 1999 10:36:12 EDT > >Yet another test for cleanliness: > >Put a drop of the 0.1N Silver Nitrate solution often used for titrating in >labs on to the Copper. > >If the surface is dirty, the Copper turns black slowly, unevenly, and the >black will rub off. > >If the surface is clean the Copper turns black INSTANTLY, evenly, and will >not rub off (except with a pencil eraser). > >It is a judgement call, (no numbers, drives ISO people bonkers!) but a real >good test. > >Rudy Sedlak >RD Chemical Company > >############################################################## >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 ##############################################################