"Micro Cooling Fan" is the use of ball bearings running round metal beads, below the point of contact, so that the activation operation is easy. Coupled with the use of ball bearing with spring, so the "Micro Cooling Fan" spring top propped outside BALL Bearing metal ring, leaving the entire weight of the rotor blades is located on the ball, and insisted on by the spring indirect top, it can be use the directions for different angles of portable products, but still prevent falling, so the ball bearing damage caused by "Micro Cooling Fan" noise generation and life impairment.