If you are wondering why phones do not need internal fans, consider the following. The circuitry inside of a smartphone does not require a fan because it is protected by thermal transmission sheets made of carbon or copper. The primary component of such a sheet is carbon, which has better thermal diffusion properties than copper. Historically, copper has been used in electronics to dissipate heat. These sheets, which are several ten millimeters thick, contain tens of thousands of layers of highly conductive carbon crystal membranes. Because the carbon in each membrane is tightly connected to one another, heat is easily converted to vibration energy and quickly diffused.
The main difference between a computer’s processor and a smartphone’s processor is the amount of energy available. The CPU and the GPU are both made to withstand a certain amount of heat. The heat generated by the smartphone processor will not damage the electronics, although the processor will shut down if the temperature reaches its maximum limit. The majority of everyday users do not exceed this temperature limit. This is because smartphones do not have the full access to system hardware like computers do.
While PCs and laptops require an internal fan to keep the CPU cool, smartphones and tablets do not. While they have CPUs and other heat-generating components, they do not have vents to dissipate heat. That means that these devices do not need an internal fan to remain efficient. However, these differences do not mean that the internal components of smartphones and tablets do not need fans. It just means that their CPUs do not produce as much heat.