Handheld devices are increasingly capable of running applications that used to require laptop and desktop computers. The requirement that these devices provide better performance with a smaller form factor or size presents significant challenges, especially with the limitations of passive cooling.
The current study presents a summary of the cooling solutions of several popular, commercially available tablets. The trends in power dissipation and thermal management techniques of handheld devices are presented.
The factors affecting the maximum possible power dissipation are discussed. The effects of the selection of the outer shell materials, the thermal interface materials, heat spreaders and air gaps are presented.
For all considered thermal management techniques of handheld devices, a figure of merit for the cooling solutions is defined as: Figure of Merit = Maximum Power Dissipation / Surface Temperature Rise, in (W/degC). This figure of merit allows for an objective comparison of the available cooling solutions.