If you own a FLIR model E4, E5, E6 or E8 and would like to use it effectively in electronics then you can easily improve it. Using a cheap (~10USD) ZnSe lens with a diameter of 20mm - the same one used in CO2 lasers - you can significantly increase the focus in such a way that you can even see the temperature propagation inside the IC. Check out the sample photos.

What do you need?
1) A 3d printer printout of this design with standard settings ie: layer 0.15, fill 20%.
2) A ZnSe lens with a diameter of 20mm.

I suggest buying 2 lenses: one with a focal length of 50.8mm and another with a focal length of 101.6mm.
For the FL 50mm, we have a better magnification even inside the IC however, we need to keep the thermal imaging camera quite close to the PCB.
The FL 100mm, on the other hand, works better for everyday use.
If you want only one lens then I recommend 76.2 or 63.5 mm.

This design stands out from other similar ones in that it does not obscure the visible light camera so you can use it normally.