Torben: As you probably know the problems with resist lift during Ni/Au electroplate have been an ongoing problem for years. Let me offer a few things to consider. 1. Surface preparation prior to photoresist application. If you are applying this over electroless Cu, use an acidified anti-tarnish after the electroless. If you are applying onto foil or after strike plate use an mechanical abrasive prep. 2. If possible use a semi aqueous photoresist. However these are becoming rarer and rarer due to environmental issues. 3. Preclean prior to plate. If you are using a soak cleaner make sure it's chemistry is compatible with the resist. Also excessive times/temps/concentrations can cause lifting. 4. Au bath. Keep the Au conc. up in the 1oz/gal range. Use a bath with a high plating efficiency, around 50%. The bath should be carbon treated on a regular basis. Use a wetter to reduce surface tension. Use a solution sparger across the face of the panel to scavenge off the hydrogen. All of these things will help reduce the resist lift problems. Since you are using sub-contractors for the plating some of these items may be hard to implement or negotiate. Good Luck! Regards Michael Barmuta Staff Engineer Fluke Corp. Everett Wa. 425-356-6076 -----Original Message----- From: TOE /Torben Østeraa [mailto:[log in to unmask]] Sent: Friday, August 13, 1999 2:45 AM To: [log in to unmask] Subject: [TN] Gold plating resist Dear collegues, When producing strip-line boards with Nickle/Hard-gold as etch-resist, it is a well known problem that the hydrogen generation in the plating baths can sometimes cause lifting of the photoresist. This results in plating of nickle and/or gold under the resist. Some tricks are known ( or at least told ) to minimize the problem, e,g, baking or UV bumping prior plating and reducing current densities. Still, I find the proces far to unpredictable and am thefore seeking advise on this problem. Does brand of photoresist make a difference?. Several plating houses have had best experiences with a product from german 'Hoechst', but this is not available anymore. We are using sub-contractors for the plating proces, but apply the plating resist ourselves. Sorry if this problem has been on this forum resently, but perhaps new information is available today?.... regards Torben Østeraa tech. mgr. Printca AS Denmark ############################################################## 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 ############################################################## ############################################################## 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 ##############################################################