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I am making an examination on the effects of adding cooling to some existing electronics (making an comparison between having no cooling of the electronics and adding a heatsink or heatpipe + heatsink). Therefore I am taking measurements with external thermocouples on critical components and hot spots on the PCB itself. These measurements has been done before with the thermocouple leads simply touching the intended measurement points, but I would instead like to use some thermal adhesive for a better/more true/quicker reading of the temperature.

My main problem is that any such thermal adhesive I have found seems to be very strong epoxies meant for fixation for ever. (For example this) Has anyone used any thermal adhesive solution that is "semi strong" e.g. will be reasonably strong in a laboratory environment but not intended to hold for ever, e.g can be quite easily removed as well.

Or essentially any tips from people experienced on doing temperature measurements on your PCBs/components or on using thermocouples in a good way in a laboratory setting measuring electronics.

Maybe it is possible to use some kind of silicone heat pads if they are "flexible" enough e.g. if you can form them etc as some kind of dough?

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  • \$\begingroup\$ It has been many years since I had to do this with a company that was very big on temperature testing/profiling of a design. At the time I believe we used 2-part superglue (glue + accelerator) to affix the thermocouples to the ICs. With just a drop, they weren't too difficult to remove. In fact we had to be very careful putting covers back in place to avoid the thermocouples popping off. I don't know how good this would be for fast-changing temperatures. Our tests took two days with only one or two cycles between max and min ambient temperatures. \$\endgroup\$ – Tut Dec 13 '17 at 15:34
  • \$\begingroup\$ Not really sure, but... what about soldering the tip to the test point? I know people doing this with J type thermocouples. Of course this is not very strong, but for testing purposes this seems to work... \$\endgroup\$ – frarugi87 Dec 13 '17 at 16:13
  • \$\begingroup\$ Kapton tape? Or I'll sometimes hold the thermo-couple (TC) in place under a screw and teflon washer. (Teflon so the washer deforms some rather than crushing the TC.) (I like the soldering idea, I'll have to try that.) \$\endgroup\$ – George Herold Dec 13 '17 at 16:36
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I've always used Kapton (aka Polyimide) tape for this purpose.

Gell type superglue work too but leaves a slight residue, e.g. BlackTak TackPack type products (wire tacking adhesive). They do chisel off with a knive if you don't use too much.

You don't say what temperatures you are going to, but I've also used tiny slices of hot melt glue and a hot air gun to melt it. More for re-working prototype designs but it might work for this too.

It can easily be removed by softening it again and using a larger glue stick to pick it off. Obviously if your surface gets close to the melting temperature then that's no use.

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I believe, but am not sure, that Omega makes a variety of therma epoxies with varying strength. You can also control tha amount. Be aware of limited shelf life.

Thermal paste and some sort of fixture might be considered.

Finally omega makes a variety of stick on thermal couples. I have had good success with the flat ones augmented by insulation on the exposed

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