Partially fill passively cooled Windows tablet with thermal paste?

I have a tablet with a passively cooled Core m 5y10c (standard 4.5W). I have now removed the plastic film between the aluminum housing and the heat spreader. I provided the heatspreader with liquid metal, as well as the CPU. Between the heat spreader and the aluminum cover I have now properly lubricated the Noctua NT-H1. Of course, the tablet is now much warmer at this point, but I can also play Portal 2 with a Bluetooth controller on the side. That was not possible before because I could not set the TDP above 5W and thus the iGPU ran permanently at almost the lowest clock. Now the device stays at 6W and undervolting still 7 ° C below the throttle limit. Since I have already read the CMOS from the tablet, I now know that the 6W maximum TDP limit can be overridden with another value.

Then next to the heat spreader I would distribute a lot of thermal paste in the hope that the heat would be better distributed over the entire back of the tablet. Or wouldn't that work? What do you say?

I would really like to go up to 7 or 7.5W in order to be able to play older Valve games and other titles smoothly. For real gaming, I still have a laptop and PC. But the little thing has a 50Wh battery and is absolutely awesome for gaming on the go, passively cooled.

It's nothing more than a desktop i3 with hyperthreading in which the TDP was strictly limited.

Normal thermal paste has a thermal conductivity that is approx. 20 times lower than that of aluminum, and can therefore only transfer heat effectively and sufficiently in the thinnest possible layer.

So it wouldn't do too much.

I glued my Samsung Galaxy S6 to a flat extruded aluminum heat sink with WLP. Structurally similar to this one, only flatter. This means that the phone remains considerably cooler than before, even after hours of gaming and charging.

I have no idea whether this is necessary for you for your wishes, or what will bring.

Wouldn't like to stick something on the outside of the aluminum housing for the time being. There are such super thin heat pipes to buy that are also used in smartphones. Just have to see how much space there's between the aluminum housing and the battery. Then you could distribute the whole thing evenly on the back with a few heat pipes. Currently, the tablet mainly only warms up in the middle.

Then just put it on a cooling pad for notebooks.

Then I can also play on my notebook. It's all about mobility. Of course, the battery life decreases by increasing it to 6W, but with the tablet battery you can still gamble for 3 to 4 hours. At 7 or 7.5W it will still be over 3 hours. I can't even gamble on the laptop in battery mode without the battery getting too hot.

Did it once and never again afterwards. According to HWinfo it cost 6 to 7% health for the battery.

With your tablet, the problem of dissipating mass and surface would remain. Currently, it is only directed onto a relatively thin piece of aluminum sheet, which does not even offer external cooling fin structures to enlarge the reactive heat transfer area to the air.

Your idea with the mini heat pipes only works if a certain temperature difference is reached, or a certain minimum temperature is applied to the pipe's hotspot to initiate the evaporation process.