When setting up a new production project for in-house potting of temperature probes, Ben Moffat, project engineer at Variohm, had a number of requirements. He wanted a potting compound that would provide the best thermal conductivity combined with an extended pot life at room temperature, and it needed to be as free flowing as possible to fill the very small cavities in the Variohm M4 to M10 sized thermistor and thermocouple probes. As these can typically work at over 100°C and can be called on to work at temperatures of 200 to 300°C, very high temperature capability was also needed.
To meet the requirements, Kevin Cook, sales manager at Intertronics, recommended Polytec TC 437, a boron nitride filled thermally conductive epoxy which cures at room temperature with a two hour pot life and low viscosity.
Moffat commented: “With Polytec we have about three times the pot life we had before and the bubbles rise to the top so we can pretty much do what we want with it. Kevin and the team at Intertronics provided a selection of dispensing tips and were helpful in guiding us through the trials process, so that now it is quite quick and clean. Polytec TC 437 is now our preferred material, especially for the high performance and difficult assemblies.”
Intertronics was also able to supply bulk quantities of the Polytec TC 437 adhesive in a Variohm green.