During the "Micro Cooling Fan" operation, the back wing of his movement will produce a vortex, this vortex will not only reduce the efficiency of the fan, and generate noise. During fan operation, the back wing of his movement will produce a vortex, this vortex will not only reduce the "Micro Cooling Fan" the efficiency and generate noise. To reduce this phenomenon, the installation angle of the blade can not be too large, and require a smooth curved blades, do not suddenly changed so much. To reduce this phenomenon, the installation angle of the blade can not be too large, and "Micro Cooling Fan" curved blades need smooth, do not suddenly changed so much.