Alternative for thermal tape to affix heat sinks on RPi3 chips?

    I'm running LE on a fanless Raspberry Pi 3B and depending on what's happening, I frequently see the RPi's over-temperature symbol (thermometer in the top right hand corner of the screen) appear. I've bought a pair of those cheap small heat sinks to stick on top of the chips, but they come with double-sided tape (which the manufacturer describes as thermal tape but I have my doubts about that) and sticking them on top of the chips has little effect, presumably due to the fact that the double-sided tape acts as a thermal insulator.

    Is there anything better that I can use to stick these heat sinks on top of the chips? Lacking a case with integrated heat sinks, I'm pretty much reduced to sticking these little ones on top of the chips with some sort of adhesive, but this tape doesn't really do the job in terms of cooling, I'm afraid.

    Suggestions, anyone?

    (And yes, I know, forced cooling and better heat sinks would be best, but fan noise and the high costs of cases and/or heat sink contraptions in my neck of the woods make that plan B.)

    // FvW

    It's not necessary to use a noisy fan. Yes the passive cooling would be the best option but in this case you always need a massive heat sink and still there should be an air flow around.

    For one of my RPis 4B I am using as a compromise a smaller heat sink + 12 V CPU fan (60x60x10mm, used but a quality grade), powered by 5V from USB port. I's enough to have a reduced rotation speed so there's no noise and the cooling is very good.

    Probably a silly comment but I've just bought an RPi4 and an Argon One case. The case comes with a couple of thermal pads but you need to peel the backing from either side to reveal the thermal paste sandwiched in the middle.

    Not a silly comment - with the rare event of some warm weather in the Scottish Highlands I was also getting a little thermometer. My solution was to buy a laptop cooling pad from Amazon. I went cheap and spent a massive £5.99

    Trust Ziva Laptop Cooling Stand for Laptops up to 16-inch, Black
    Trust Ziva Laptop Cooling Stand for Laptops up to 16-inch, Black
    www.amazon.co.uk

    works really well.

    You may be surprised how well ordinary silicone sealant from the hardware store works. Use the absolute thinnest possible amount to minimize the insulative properties of the silicone. Epoxies work well too (and you can even buy expensive "thermally conductive" epoxy), but with epoxy you will never get the heat sink back off if you want to change it later.

    If you are daring you can make very fine copper shavings to add to the silicone to make it more thermally conductive, but then it will also be electronically conductive so you must be certain it stays only on the top of the chip and doesn't ooze over the sides when you put the heat sink on.

    There is also this stuff that I have never tried, but I suspect is identical to hardware store silicone:

    Thermal Conductive Heatsink Plaster Viscous Adhesive Compound Glue For PC GPUSfi

    Thermal Conductive Heatsink Plaster Viscous Adhesive Compound Glue For PC GPUSfi | eBay
    Find many great new & used options and get the best deals for Thermal Conductive Heatsink Plaster Viscous Adhesive Compound Glue For PC GPUSfi at the best…
    www.ebay.com

    Hainziye HY910 Thermal Grease CPU LED IC Heatsink Glue Plaster Paste Compound

    Hainziye HY910 Thermal Grease CPU LED IC Heatsink Glue Plaster Paste Compound | eBay
    1X Thermal Glue. This can only delay our service. - Got a problem?. No Problem.
    www.ebay.com

    Regards,

    craigr