Phil, I don't understand why you are using conductive epoxy to adhere the thermocouple to the die. Correct me if I am wrong but according to the Seebeck effect, any dissimilar metals that are in contact generate a thermoelectric circuit and thus current. If you are adding additional metals to a thermocouple system which is designed to have only two basis metals- you are generating additional current which entirely skews the results. Please coorect me if I am wrong, but this is according to my Omega temperature handbook. [log in to unmask] ___________________Reply Separator_____________________ Steve- One of the tests that I perform on reflow systems when I evaluate them is an IC internal temperature test. I have a board with a QFP84 mounted on it. I have drilled down to the die and attached a thermocouple to the die with conductive epoxy and filled the hole up with non-conductive epoxy. I also attach a thermocouple to one of the lead/pad interconnects of that device. I run the board through a typical profile and observe the difference between the lead/pad interconnect temperature and the internal temperature (of the die). Some of the older Convection/IR systems, particularly those with a high amount of IR (such as the lamp systems) would take the internal temperature above the lead temp. though some did not. Of all of the "newer" Convection Dominant (Forced Convection) reflow systems, all of them allowed the die to remain cooler than the interconnection - usually by at least 10 deg. C or more. Only one machine (no longer in production) brought the die up to equilibrium with the lead. Hope this helps. Phil Zarrow ITM, Inc. Durham, NH *************************************************************************** * 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] * ***************************************************************************