Hi Jan, Where you put the thermocouple depends as to what it is you want to measure. In wave soldering you will get a definite temperature gradient from the bottom side to the top side of the PCB. The gradient is less for thicker copper plating in the hole because of the better heat transfer. The gradients in the epoxy of the PCB will be larger because of the significantly lower thermal conductivity. So, if you are interested in solder reaching the top surface and to wet properly, you place the thermocouple on the top land. If you are interested in the overheating of the PCB you would want to place the thermocouple into the epoxy at the bottom side of the PCB. Werner Engelmaier Engelmaier Associates, Inc. Electronic Packaging, Interconnection and Reliability Consulting 23 Gunther Street Mendham, NJ 07945 USA Phone & Fax: 201-543-2747 E-mail: [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************