After more than 3 years hard-working, my laptop's CPU and GPU temperature became higher and higher. So I finally make up my mind to tear it down to pieces to do a tougher cleaning. And more, I find that there's a little gap between the GPU and the thermal-pipe, stuffed with very unpleasant silica gel, which is the reason why my GPU's temperature never been lower than 80℃, which is unsafe and harmful to the GPU and other hardware close-by. To replace that, I brought a little piece of copper which thickness is 1.2mm to fit into that gap. And it turns out that the copper is a little too thick for the gap, but after the test I think it still do the work so maybe some time later I'll buy a thinner one to replace it. Here's the photo I took.