Chiriac, V., Malloy, S., Anderson, J., and Goodson K.E., 2015, “A Figure of Merit for Smart Phone Thermal Management,” Electronics Cooling, Vol. 17, pp. 18-23.
With smart phones and other mobile devices available in a variety of sizes and shapes, it is challenging to think in a consistent and comparative manner about the effectiveness of the thermal management solutions that they employ. This is growing more important as the mobile and wireless industries and associated research communities explore novile mobile cooling approaches. Here we define a universal thermal figure of merit - a dimensionless Coefficient of Thermal Spreading (CTS) - that can be calculated using either numerical simulations or Infrared (IR) surface temperature imaging and can be used to compare the thermal design effectiveness of many mobile devices and power levels. The proposed CTS figure of merit quantifies the effectiveness of heat spreading within the device by means of the uniformity of the surface temperature, and addresses a long-time need to quantify the thermal design effectiveness of various mobile devices which are skin temperature limited.