Rather than add this post to the rather large, “Raspberry Pi 4 Temperature” thread, I though it easier to start a new one, relating to my specific question.
It is now generally accepted that the Raspberry Pi 4 boards can, under certain conditions, run a little ‘hot’, particularly in the new ‘official’ case, and although the promised firmware update will hopefully reduce this a bit, there are still a number of users, such as myself, who wish to attach a heat-sink to the board.
One such item is (or rather was!) available from Pimoroni, with the dimensions 40 x 30 x 5 mm meaning that it can only be fitted (just!) in one position, where it will cover, not only the CPU, but also the memory chip and radio module as well.
This is fine I suppose, except of course for the fact that as they are all different ‘heights’ it is difficult for a single piece of thermal tape to make proper contact with all three. As the small piece of 3M tape supplied does not cover the whole heat-sink anyway, my first thought was to remove this, and replace it with something which did, so I have ordered a piece of 0.5 mm thick Akasa AK-TT12-80 Thermal Adhesive Tape, which I will then cut to size.
Possibly though this is not the best option, and would something like a piece of ARCTIC - Thermal Pad 50 x 50 x 0.5 mm Thermal Compound Conductivity Gap Filler be more suitable, or as the chips are different ‘heights; possibly a 1 mm, or even 1.5 mm, thick thermal pad would be a better alternative?
I would be interested to hear what other users think about this idea anyway, and which option they would go for, if indeed they were going to fit one to their Pi 4?