[robinduckett]

Nope, they use a liquid at room temperature metal alloy instead of thermal compound as it’s supposed to work better.

[bravetraveler]

Yea, imagine flowing mercury - it's a bit like that. Typically made of tin, gallium, and indium

(and probably some proprietary-fu)

Supposedly better thermal conductivity; downside is... that applies electrically too

It sounds like Sony (or Foxconn/whoever) is putting too much on there. A surprisingly low amount will last/suffice