The cooling systems of the CPU have in their competence mini and micro-channels whose performances at intensifying the thermal transfer have been discovered and proved. It is justified the interest in studying the shape of these components, their possibilities of manufacture, the phenomenathat occur in channels of small dimensions and processes of heat transfer.The current article aims to realize a brief presentation of mini and micro-channels situated inside the cooling system of the CPU, while in the second part is proposed a calculation model for heat transfer in circular mini and micro-channels. In the case of the analyzed channel, it is realized the modeling of the process of heat exchange in micro-channels. The used model is validated by comparison with numeric results obtained by authors in specialized literature.
