Yasmeen, What you are seeing is most likely due to localized insufficient supply of copper ions at the cathode due to no agitation. In other words, you have become "mass transfer limited" in the regions where mixing (which supplies 'fresh' copper ions to the surface) is poor. This causes the "boundary layer" to become thicker, making the deposit powdery rather than smooth. There are several options to eliminate this. Obviously, improving agitation would help. You might consider raising your copper concentration. You might also wish to consider bath additives such a brighteners or levelers. These can be evaluated quickly and effectively using a Hull cell. I hope this is of some help. Don't hesitate to contact me if I can explain further. Jonathan Meigs AlliedSignal Oak-Mitsui -----Original Message----- From: nishath yasmeen [mailto:[log in to unmask]] Sent: Tuesday, January 05, 1999 3:58 PM To: [log in to unmask] Subject: [TN] Porous copper deposits Hello everyone! I have a question about the effect of agitation in acid copper plating tanks. Why is the copper very porous and burnt when there is no agitation in the tank? What actually causes the copper to be porous? Thanks in advance, Yasmeen ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################