[Xperia Z5 General] Verity.:
Hello Z5 users! :o

It's my first thread ever posted by me so please forgive my lack of knowledge in creating new threads. :p

Warning! If you decide to do that mod yourself, proceed with extreme caution, I'm not responsible for breaking your device as it's very easy to break something.

I decided to crack open my good old Xperia Z5 and do something to increase performance and improve heat dissipation. :cool:

Firstly, I spent some time in watching teardown videos to have a look at the cooling system. It features metal backplate behind an lcd and two copper heat pipes that are soldered to the metal plate. I took some pictures of cooling system:

There is metal shielding above the cpu and couple other elements. Between the metal shield and copper pipes, there is an inefficient thermal filler, so I removed it.

Next, we've got the motherboard. The metal shield is held by metal clips, so you need a little bit of leverage to lift this up. Between the shield and cpu is a thermal pad (it's extremely thin) which I think is inefficient as well, so I also removed it. Instead of this thermal pad, I just used a little bit of thermal paste which I needed to spread on the cpu (it must be a thin layer). After closing it up, I had to use something to close the gap between metal shielding and copper heatpipes. Firstly, I used 0.5mm Thermal pad with better conductivity, but it was too inefficient. Eventually I sanded a little bit the shielding, it had that uneven surface as you can see on this pictures.

I do not recommend using "metal based" thermal pastes, they're usually conduting electricity and that is undesirable.

I didn't do any pictures inside of this metal shielding, because i added there some thermal paste before and if I opened that it'd very messy. :p

The uneven surface is the problem, the heatpipes are around 0.5mm higher than the metal plate that are soldered to. I decided to put copper pad. I didn't know the exact thickness back then, so I bought a 1.0mm one and it was too thick so I sanded it down so it'd fit, I found that it should be around 0.2-0.3mm - If you put too thick copper pad and screw the motherboard, it'll push on the backplate and on the back of the lcd too hard and the dark points will appear (I was cautious so i unscrewed it and sanded the pad, so my lcd is fine). :D

You can even sand a little bit the copper pipes, so the surface will be more even and flat, it'll improve the heat transfer a little bit. I've spread the same thermal paste on both sides and just put everything back together.

The heat is going from the processor to shielding, through the copper pad and finally to the copper heatpipes. It is better from the factory solution, because the heat is transferred almost only to heatpipes and the lcd will be a little bit cooler to the touch, because it's not touching the metal backplate behind the lcd directly.

[IMG="I reopened it to prove it fits (the thermal paste is squeezeed, so it fits well)"]https://imageshack.com/a/img921/4019/TERDdB.jpg[/IMG]

Do not add that much thermal compound. Please, don't point to me, that I'm using too much thermal paste, I'm aware of that.

Also, I know that the heat transfer surface under the copper pad is terrible, but it's better than stock solution. I've tried using those "soft" thermal pads next to heatpipes to increase the surface, but in the end I discovered that the results aren't that better and the lcd was heating up much more.

And the results are in the attachments. I didn't do a before and after, I've based the improvement on the average points in benchmarks. So check your scores in those, and let me know your stock points, so I'll know better if the mod was worth it. :p The screenshots are from Geekbench, it's on google play

My antutu benchmark score =112612

Other users average score = 97159