MF01 Mini / MT07- Mod/Upgrade - Copper Heatsink Cover Plate

Ah ok. I thought it’s design. That sounds nice.

Thx for clarifying, wasn’t paying attention.

@Zozz, thanks for explanation and the latest results :+1:

The idea to use thermal silicone pad is not bad, nice pics, thanks for the work.

It’s really important to spread the thermal compound on the defined surfaces, like shown in the description in post #1 and on this pic below.
Before mounting it should look like this, but here is a bit too much thermal compound paste spread on in this pic, just to show where it should be.

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After mounting, use a cotton pad to clean up excess residues.

This gap is around 0,1 and 0,2 mm after mounting the copper heatsink plate. It depends on manufacturing tolerances and tolerances of the components (7135) and also of the pcb and soldering process. Designing this gap closer is possible, but it brings some risks. It may be possible that another production batch of driver pcb’s will not fit or there will be no gap. Tolerances differs often on pcb’s.

Therefore the idea to use thermal silicone pad is not bad, but in most cases you will achieve better thermal conductivity with grease/paste.

As you said you can’t design it to get too close to 7135 top because if it has a bit more solder under you can possibly break them tightening the copper. You need a bit of clearance. That is why I tried silicone. It works like a gum and reach the 7135 sides too because of the pressure. So more contact surface to get off the heat. I maybe only use paste on that contact ring on driver. I think I will disassemble it a few times to get best results.

I’ve always learned that thermal grease is only to fill in the tiniest of pores and scratches between two metals. You guys are killing me with just glooping it all over and trying to fill in these giant gaps. :confounded: Lol

Recently, I needed to buy Arctic Thermal Pad and it works quite well in one flashlight. Cutting the right pieces is probably a better solution than dirtying everything around with paste.

Ah too bad I missed this. Would love to improve my 3 mf01 minis!

In for 1-2pc if there is a 2nd batch

I will put you on the list for a possible second batch, will provide it soon in post #2, if there will be enough interests it could be realized.

You’re absolutely right, thermal grease should be used very barely, always use as less as possible of it.

In this case we are taking about close a gap in the range of 0.1 to 0.2 mm as max. Between GND surface and copper plate is nearly no gap.

if there are 2 pieces left, please consider me.
Thanks,
olles!

Thermal pads have worse conductivity than paste…but their big advantage is that they are solid. Paste may move around and leave you air gaps just where you don’t want it.

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I think that’s only true when both are used properly. Since we are not using the paste properly I think we have to throw this whole statement out.

BTW, are these thermal pads like the ones used for cpu’s? One use only, once separated you have to throw it away and use fresh pads. Plus you have to get the pad really hot in order for it to conform to the proper shape. Maybe newer style pads are designed differently?

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My thermal pads being used in Audi A8 and Q7 and Q8 Bang & Olufssen amplifiers :smiley:

Under the MOSFETs? I wonder why they didn’t use thermal paste like other amps.

Did you buy extra from them? Why do you have them? So many questions.

I don’t know where they put them in exactly.
Don’t know maybe easier to apply thermal pads in exact same amount than paste.
Didn’t bought them.
I work in an automotive electronics manufacturing company where we produce so many type of electronics for cars. B&O is one of our buyers. We make electronics also for Harman Kardon, Delphi, Valeo, Aptiv, Honda, Porsche, Mercedes… But I don’t work at that area just asked collegues for thermal pads and they got me a few.

many devices use thermal pads now a days in production, its more consistent in application, and is easier and cleaner to work with.

in most cases that outweighs the minor differences in thermal conductivity, especially in production gear that has a large tolerance on the thermal characteristics.
i would wonder however if there would be manufacturing tolerances on this light that are so great that there would be measurable differences in the clearance between the copper sink and the chips themselves.
it would probably not be known until a large number of devices have had the copper sink in them.

What thermal paste did you use in your experiments man of ligjt? You obviously worked with heatsinks a lot, what paste (brand type) do you think would be best for this application? I could use professional opinion.

I’ve built plenty of PCs in the past and never had any issues with thermal transfer from CPU to heatsink, so I think I’ll just use thermal paste for mine. Just means I’ll need to get a new tube of Arctic Silver as the one I have must be well over ten years old, and I think the shelf life is probably a lot less than that.

For my tests I used Arctic MX-4, but only because I have a lot of it. Its a good one with relatively good thermal conductivity value of 8.5 W/mK, its not that budget.
Just for comparison, most common basic thermal grease/paste (white) have a value of 1-2 W/mK, but it will do the job also good enough.
So just use any kind you already have at home. And put only as much as necessary and as less as possible to the surfaces.

I’d suggest IC Diamond 24karat. Had a lot of pastes in the past and this one is the only that won’t dry out in a month or two.

Also all components i’ve used with this paste got noticably warm much faster than any other thermal solution.

or maybe it’s just me... but i can recomend it 100%