Go Passive with Home Made Heatsink

I chose VIM3 to be my daily SBC drive, so I want it to be quiet. I tried a 40x30x5mm heatsink for RPi4, but not satisfied with the result, I decided to make one. I don’t have CNC machine, so I bought a small hacksaw and a pack of files from Walmart for less than $10.

The raw 150x70x10mm heatsink is from Amazon, for $11. Here is the size comparison:

At first wanted to be lazy, just cut a 70x30mm piece and sticked it on with thermal tape, but it doesn’t feel secured, one reason is the chips are not even, I have to shim them with little copper pads ($10 for 100 pieces at Amazon), there are too many moving parts in the mix.

So I decided to spend a little more time make it full blown. In order to make the heatsink contact with the chips, I hand made a extruded block with 1x1/4" 6061 aluminum flat bar (I was able to find a 4" piece for $1.68 at local metal supplier, the silver one in the picture above). I cut off a corner to avoid the tall components, and bonded it to the heatsink with Arctic thermal epoxy. To make the block fully contact with the chips, I put some 1.5mm thermal pads in between. The thermal pads are squeezable, which helps to adjust the pressure since there are no springs on the M2 standoffs.

Because the WiFi chip is covered up by the heatsink, I made it a little longer so that I could install two “mushroom” antenna on the heatsink.

Now I’m waiting for Linux 5.10 kernel and the Mali GPU support to push this little computer to its peak.

The copper shims are not used after all:


Hello, I always love these types of projects. Plus, I loath excess heat where electronics are concerned. So thumbs up.
However, to truly appreciate this project, it would be nice to see both ambient(room) temp and corresponding VIM3 idle and high load temps.
Those types of WiFi/BT antenna are new to me. Anything to report on their performance?

Nice post.

Hello! in fact, it does not matter how the antennas look externally, it is important how they show themselves in operation, in signal reception and the radius of their operating range.

Yes, exactly, that is why I asked about their performance and not their appearance. :upside_down_face:

I also took this into account when I gave my answer to you :wink:

I’m confused, to what question do you refer? I was asking the user O635789 about their experience with their setup. However, if you are also using that type of antenna on your VIM3, I would welcome some performance details. i.e. a comparison between those and others, for instance the Khadas supplied or typical dipole 3-9dB external antenna.

I have described in general how it works in general.

Personally, I do not use WiFi for TV-boxes, since I watch movies online weighing 130 gigabytes, I work strictly on LAN to avoid packet loss.

@O635789 I see you are using 2x 5.8 GHz antennas, you need a 2.4GHz antenna for the wifi and bluetooth, you will damage the RF module using an antenna of wrong frequencies,

and @RDFTKV I presume that the 2.4GHz transceiver won’t work at all, so “bad performance” is my quote


Actually, we also designed a bottom mount Heatsink for VIM Serial SBC months ago but didn’t launch:

Have fun!


@Gouwa it seems like there a lot of products the khadas team prototypes with, that never reach the final user :open_mouth:

looking forward to see what other things you have created :slight_smile:


A pause in sales can be connected only for one reason, it is necessary to bring the product to mind, conduct tests and only then offer it to the end consumer.

yes I know how product launches work :wink:
I’m referring to how there is so much creativity to make things in khadas’s office :smile: Its something that I can admire about

Like the style, I guess you didn’t release it because the bottom mount design is not very effective. Now I see Rock Pi 4 made a point to have the chip on the bottom, so everything could build up from the rock solid metal foundation.

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I have been using an S922X-H soc for coming linux kernel and it have been running cool under full load at around 61-62°C max and all this with passive cooling whole I have been using vim3 with active cooling with almost the same temperature which makes me think that we should be able to achieve the same with a full size heatsink for vim3 and no need for active cooling anymore.

Thanks for sharing your work.


OK here is a simple test result. I ran donut for 10 minutes (100% load), the CPU temperature stabled around 47°C. When browsing the internet (not YouTube though), the temperature is about the same as human body temperature (36-37°C).

There is a weak link in this setup. The thermal pad I use to fill up the gap is a cheapest one. Amazon has some more expensive thermal pads have much better specs, I just don’t feel it’s necessary at this point.


Speaking of the mushroom antennas, I’m sitting 6 feet from a 5 GHz hot spot and did a little test.

With the antennas on iwconfig says: Link Quality=70/70 Signal level=-38 dBm
With the antennas off iwconfig says: Link Quality=60/70 Signal level=-50 dBm
With traditional antenna 40mm antenna iwconfig says: Link Quality=69/70 Signal level=-41 dBm

So yes, these mushroom antennas are good.

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@O635789 did you test 2.4Ghz ?

If you are really so interested in what WiFi tests, then the question needs to be asked more specifically, which router, how far from the router is vim, what obstacles, etc., only then you can really draw some conclusions!

Have a nice day, everyone! :stuck_out_tongue_winking_eye:

Of course, I meant a relative comparison only of the type of antenna used on the VIM. It assumed every other variable in the environment was the same.

Khadas has very high quality antennas for this type of device, and the person just got creative with updating the look for vim.
By the way, have you ever seen antennas on your smartphone? however, it doesn’t work badly, does it?

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