Should i use Thermal Paste for Heatsink?

edmaul69

@retrofreak89 for it to actually stick you need a 2 part thermal compound. You mix the 2 together and it makes a paste that dries hard. With regular thermal paste you can risk your heatsink sliding around when it warms up. I have 2 part thermal compound but i dont use it. I just bought a copper heatsink instead of using an aluminum one.

caver01

@retrofreak89 I had some Arctic silver and gave it a shot over a year ago. My sink has not moved a bit, and my Pi is mounted upside-down in my case. I occasionally check to make sure it hasn't moved and so far, I am pleased with it, but I know that a casual bump with a USB cable or something could push it off center. I might be worried if my Pi was mounted on edge so gravity could pull on it over time. The key is to use just the right amount and no more. It should fill the gap, but if it squeezes out, that's too much. There is some vacuum effect, and this stuff is super sticky which helps.

If I had a 2-part CPU compound I might try to replace my arctic silver, but I could also come up with some kind of alignment bracket and nylon zip ties or something to hold it on.

RetroFreak89

@edmaul69 hmm ok thats clear.
Should i leave it be then?
Or is it worth it to try i mean my pi is in one spot and doesnt move nor do i take it anywhere..
But if its not going to help a ton then ill just leave it be..
I thought maybe if it sticked well i would of overclocked it

RetroFreak89

@caver01 hmm this one om not sure if its high density like the artic one so im not sure if its sticky
Does it help a ton with temps or just a few degrees?

caver01

@retrofreak89 Before I added the sink (which I simply cut to size from an old Pentium CPU heatsink) I was able to frequently and easily create overheat throttling. For example, simply loading some games and letting them sit at their demo screens would cause the Pi to slow down. Golden Tee for example would cause overheat throttling.

I added my sink and I have never seen an overheat since. That was over a year ago. My cabinet is a large, flat, 4-player cocktail style box, but I have no active cooling (no fans). The Pi is mounted behind my 19" display which probably throws off additional heat. It has been a while since I checked temperatures, so I could be right on the edge for all I know. But I won't setup another Pi3 without a heatsink, and I will probably used thermal paste again since I have not had a problem with it. Hardening CPU compound would probably be better, but I don't have any.

DD-Indeed

I have been testing aluminium heat sink with double sided tape and that is propably the easiest solution. One thing is sure: those small heatsinks that are used usually for video card's memory chips are way too small for proper cooling. I did some measurements and used dremel to cut off part of the bigger heatsink I used.

Due the Raspberry Pi 3's design, it's impossible to fit bigger than 30 mm x 30 mm heatsinks, as some of those parts on the board are on the way, as the main CPU chip is lower than those. But having that 30x30 cooler, it's more than enough and you can get fans for it (either 30 mm, or then just buy 40 mm, as you can screw it in and it will stay there for sure, even with one screw).

About the paste, I think that best overall solution would be to use thermal glue, if you are using that bigger cooler. Trouble with RPi is the design, which does not allow easy solutions to attaching the cooler properly and using regular thermal paste. I myself propably go for that thermal glue solution in oncoming weeks.

caver01

@dd-indeed said in Should i use Thermal Paste for Heatsink?:

I have been testing aluminium heat sink with double sided tape and that is propably the easiest solution

I would HIGHLY DISCOURAGE the use of "double sided tape". While there are products that function that way, we have had many reports of sellers cutting corners. Unless you are absolutely certain that you are using thermal transfer "tape" designed to conduct heat, statements like the above can be very misleading:

People might not know the difference between thermal tape and double-sided cellophane, or even foam tape.
Improper ouble-sided tape can insulate rather than conduct heat
Not all supposed "thermal tape" is created equal
Although easy, a taped solution could make the problem worse
People may not realize that their heat sink is fine, but that the adhesive is the problem
There are sellers that include a bad tape product--so you can't assume that you have good thermal conducting tape just because you bought it as a "kit".

DD-Indeed

@caver01

I didn't courage anyone to use it, I just said, that it's the easiest way.

caver01

@dd-indeed Understood. You described better alternatives in fact. However, we have had other threads, long threads, discussing the best cooling options and there are many people out there who are misguided by the use of double-sided tape. I had to point out how that can be a big mistake.

RetroFreak89

Alright not sure what i should do tho..
Should i go ahead and use the paste?
Im afraid it will fall off easily

caver01

@retrofreak89 Since you have the paste, I recommend that you try it. Make sure everything is clean, even of finger oil. You can probably find a video online of someone doing this the right way. Use just enough paste for coverage and so it sticks. No more. If you use too much (if you can squeeze it out the sides, it is too much). If too little, you only get coverage in a small area and you are not conducting the heat. Just right is full coverage, no squeeze out (or the squeeze finishes the coverage).

Then, see if the vacuum effect is enough to hold it on and monitor it. You might be just fine. If it starts to slide, well, now you know and you can pull it off, clean it and use a harder thermal CPU compound. Mine has been working and not moving for over a year. Heat, cool and re-heat (power cycles) can make it firmer over time.