cm²·°C/W
square centimeter Celsius per watt
Areal thermal resistanceexact by definition
The square centimeter Celsius per watt is 10⁻⁴ m²·K/W. It is the thermal-interface-material unit: thermal grease is quoted around 0.05 to 0.5 °C·cm²/W, and a pad two or three times that. The area normalisation is what lets one number describe a material that will be used under dies of any size.
Watch out: A TIM figure is only meaningful with its bond line thickness and its clamping pressure. The same grease measured at 25 µm and 100 µm gives numbers that differ by a factor of four, and vendors are not always eager to print the test conditions.
| 1 cm²·°C/W | 0.0001 RSI (m²·K/W) |
Solvers that use areal thermal resistance