| CPC F04D 29/522 (2013.01) [F04D 19/002 (2013.01); F04D 29/325 (2013.01)] | 6 Claims |

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1. An axial-flow heat-dissipation fan, adapted for an electronic device, comprising:
a frame, having an inlet, an outlet, and an inner wall connected between the inlet and the outlet, wherein the inner wall has at least one rough region; and
a blade wheel, rotatably disposed in the frame and located between the inlet and the outlet, the inner wall surrounding the blade wheel, an air flow generated by rotation of the blade wheel flows into the frame via the inlet and flows out of the frame via the outlet, wherein a gap exists between a blade end of the blade wheel and the inner wall, a laminar flow is generated at the gap when the blade wheel is rotating and the blade end passes through the at least one rough region so as to prevent a backflow generated at the gap, a flowing direction of the backflow is opposite to a flowing direction of the air flow, wherein the at least one rough region has an etched microstructure, and a roughness of the at least one rough region is defined by an etching depth of the etched microstructure of 10 μm to 45 μm and etching particles of 15 to 150 per centimeter.
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