Thermal resistance, for one. There's always going to be a temperature gradient from the hottest hotspot to the evaporation surface of your cooler. If you want y

Thermal resistance, for one. There's always going to be a temperature gradient from the hottest hotspot to the evaporation surface of your cooler. If you want your cooler to be at 100C, your hotspot is going to have to be significantly hotter: can the chip handle running at 150C, or 175C?