Every morning, after adjusting of chemicals, we run a 1"x1" pure teflon which is sodium etched dummy from the PTH line. The last step of the PTH line is 30 min of electroless copper plating. Every morning, the dummy reads a copper thickness of 60-70 u in. However after running about 3-4 hours of real production panels in the same PTH line, the copper thickness measured dropped to 25-30 u in. We make addition of chemicals every 2 hours. I am just curious to know why. There are no PTH voids. Just copper thickness is low. Can any one help. My e-mail : [log in to unmask] Thanks!!!!!!! Francis ################################################################ 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 ################################################################