Hello jhwm, Do you mean the wall of a plated through hole wall or the wall of a particular plating tank? Copper plating - electroless or electrolytic? Who's chemistry? Hans ~~~~~~~~ Hans M. Hinners WR-ALC/LYPME Bldg. 640 Materials Engineer 380 Second Street, Suite 104 Manufacturing Eng. Sec. Robins AFB GA 31098-1638 912-926-1970 (Voice) 468 - 1970 (DSN) 912-926-7974 (Fax) mailto:[log in to unmask] > Technetters, > My question is: What is the white substance adhering to the wall of the > plating copper solution bath. > Many thanks in advance... ############################################################## 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 ##############################################################