a paper written by two flomerics executives, m�rta rencz and andr�s poppe, as well as

the paper explains that structure functions provide a one dimensional representation of the heat flow path of thermal systems and can be obtained by fast and simple thermal transient measurements. the usual way of generating structure functions considers only one heat path. heat is switched on a point in the structure and the temperature of the point is recorded as a function of time until a steady state is reached. the structure functions are determined by direct mathematical transformations from the measured transient curves. there is always a certain error in these measurements due to parasitic heat flow moving in other directions than the one dimension that is being measured. parasitic effects can consist of natural convection, radiation losses, and conduction through the fixture itself.

the new method developed by the flomerics and bute researchers improves measurement results by accounting for parasitic heat flow. this method measures the parasitic heat flow path in addition to the thermal transients and then subtracts the thermal impedance of the parasitic branches during the phase of generating the structure functions. the paper presented an application example involving measuring the effective thermal conductivity of a patterned printed circuit board. the paper also included the results of a set of verification experiments in a vacuum chamber that considered the effects of parasitic heat flow paths with single parallel thermal resistances. the authors are currently working on considering parallel heat flow paths with their structure functions.

rencz and poppe joined flomerics when flomerics purchased micred - a hungarian based company formed in 1997 as a spin-off from bute. rencz is now chief executive officer and poppe is the chief marketing officer of the micred subsidiary of flomerics. micred’s main product is the "t3ster" (pronounced "trister"), which provides fast, repeatable and accurate thermal characterization of ic devices, including stacked-die and system-in-package devices. the t3ster provides nondestructive dynamic thermal characterization of packages semiconductor devices such as diodes, bjts, j-fets, mosfets, thyristors, power leds, mcms and other electronic and mems components.

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