Hi There, There is a similar test solution of cupric chloride (50 g/l) plus HCl 200 ml / l RT. copper goes dark brown. Pink spots indicate invisible acid resistant material, like the very last stage of dry film development. I agree silver works as well. Besr Regaeds, Ken McGowan ----- Original Message ----- From: "Brown, Matthew" <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, March 14, 2001 12:33 PM Subject: [TN] > Does anybody know of a chemical that can be used to detect mono-layers > of organic resist on top of copper? > We've had issues in the past with resist residues left after develop > causing plating problems. A fellow engineer > mentioned that he had heard of a stain that would leave any contaminated > areas on the Cu a different color. He > did not know what it was however... > > Matthew Brown > Metal Plating Engineer > International Flex Technologies > Phone: (607) 658-5032 > Pager: (607) 778-4554 > > -------------------------------------------------------------------------- ------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL > Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > -------------------------------------------------------------------------- ------- > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------