Hello Ji, We have been experiencing the same situation in our facility. The process we used was Shipley 5700B micro-etch which is basically a H2SO4 / H2O2 combined with a stabilizer system (5700B). This is a normal degradation of the stabilizer that occurs with time and total workload. We resolved this problem by installing a filtering unit on this bath. 1.5 turnover/hour is sufficient to remove the residue. Have you considered persulfate instead of sulphuric/peroxide. You would most likely eliminate the resisdue problem and enjoy a better surface topography. Regards, Charles Desroches Technical Advisor Viasystems Canada inc. (Granby) Voice: (514) 372-8111 ext: 2257 Fax: (514) 3788-5110 > ---------- > From: [log in to unmask][SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum.;[log in to unmask] > Sent: Monday, March 09, 1998 9:33 PM > To: [log in to unmask] > Subject: [TN] Organic residue in Microetch bath > > I need help to minimize organic contamination occuring in Microecth > bath in > pattern plating bath. The contamination is a brown, gummy material. > When the > solution is nearly to be discarded, the contamination occurs and > floats in the > surface of the bath. If the solution is not restarted, black spots on > the > surface of copper can be seen in inspection and will cause open > circuit in > etching process without correct action. > Our microecth bath is made up of H2SO4&H2O2, using 746W(SHIPLEY > CHEMICALS) as > stabilizer. No filter pump is employed in this bath. > Can anyone offer suggestions the eliminate this residue? > Thanks in advance. > > Ji Jiancheng > > ################################################################ > TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for > additional information. > For the technical support contact Dmitriy Sklyar at [log in to unmask] or > 847-509-9700 ext.311 > ################################################################ > ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################