what component is this and should I apply thermal paste on this as well? Laptop overheating (85c)

Yesterday I disassembled the laptop (5.5 years old) but to my disappointment, I found a component on the motherboard with one screw missing and on unscrewing the second one I found out that it had the same shiny surface as in cpu/gpu. I was confused if it was also supposed to be applied thermal paste or not so i left it as it was. Later on I found no temperature difference even after replacing the thermal paste with new one and dusting off the vents. Under heavy load tempertue is crossing 90c and normally they are 50-60c. What should I do now to reduce the temperature? I have already tried undervoltaging and tweaking the power settings in control panel but it also added to the dismay.
please Click HERE to see the pic.