Hi Jim - I have used impedance spectroscopy techniques to evaluate a potential solder paste candidate and as a method of process control. The test is very easy to conduct but you do need to have a good understanding of how to generate a equivalent circuit model for the solder paste you are testing and you do need to build up a use history to understand how the modeling relates to manufacturing problems. The folks at ACI/EMPF in Philadelphia are a good source of info (contact Greg Brobjorg at 610-362-1200, ext. 218 for more info on both the technique and equipment) or shoot me an email with more specific questions. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Jim Kittel <[log in to unmask]> on 04/14/99 04:02:37 PM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to [log in to unmask] To: [log in to unmask] cc: Subject: [TN] Impedance Measurements of Solder Paste Technetters: Is anyone using impedance measurement as a process control in their manufacturing area? I have a copy of a paper from the EMPF published in the April/97 edition of 'Assembly' and it describes this process. Looks like an easy way to characterize paste. Anybody using this technique to identify bad paste? ################################################################ 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 ################################################################