Mounting heatsink precaution


#1

Is there any precaution when mounting the heatsink to rockpi 4B ? I have 2 board now broken after mounting the heatsink


#2

Please send some pictures of the back of the damaged your ROCK Pi board


#3

there is no physical damage actualy , I still investigating other possibility, should I delete this topic ?


#4

I had the problem with heatsink. The square embossing rounding the cpu is pressing a choke and broke it. As a precaution, I filed out critical areas, please see the picture.


#5

The photo gives the impression that the circuit board and most components around the CPU were contaminated with thermal paste. This can cause short-circuits, as thermal paste contains high amounts of metal, which makes it conductive even for electrical currents.


#6

:+1:@Zoran

These two areas do need to be handled with care!

But in fact, be careful with the assembling, there’s no interference in these two areas

please be careful and careful when assemble the heatsink, because of the heatsink is metal!


#7

In my case , the board is won’t boot, but the problem is not coming from the heatsink, it is because I am using phone charger which can only out 5V while the board need more than 5V, problem solved when I replace using charger which have output 12V like QC 3.0

Thanks


#8

that is great! finding the problem and fixing it by yourself


#9

Your pictures are proving my point: the embossing is wider than the CPU and the choke is almost as high as the CPU. There is no point in having that embossing, anyway.


#10

Not every thermal paste is containing a metal. The white one usually doesn’t, and it is also used on transistors isolated from the heatsink, like those in PSU and audio amplifiers.


#11

That’s right, my mistake, it gave the impression that all pastes contained metal, it should have been called many pastes contained high quantities of metal. But the color is no indication of whether metal is contained or not. Powdered metals can be white or light grey. In the meantime so many different kinds of heat conducting paste are sold, for utopian high prices up to extremely cheap and partly the containers are badly or not at all labelled. I think it is safer for casual hobbyists to assume that the paste is electrically conductive.


#12

Embossing is to guide of the silicone grease
we adjust the width if the results improve


#13

On my side, to avoid this issue I put a little copper pad between the heatsink and the processor. I put Artic MX-4 thermal compound on the two sides of the pad and everything work well. Temperature stay between 39C and 42C when I play movie with Librelec. I do not tested it with sbc_bench…