Patent ID: 8360747

Claim:
A miniature fan comprising, in combination: a housing including a mounting portion having a shaft seat; a base mounted to the mounting portion of the housing, with the base including first and second faces spaced along an axis, with an electrically insulating outer layer provided on the first face of the base, with a bottom layer provided on the second face of the base, with the base further including a coil unit intermediate the electrically insulating outer layer and the bottom layer and integrated into an interior of the base, with the coil unit electrically connected to a drive circuit; and an impeller including a shaft and a permanent magnet, with the shaft coupled to the shaft seat of the housing and rotatable about the axis, with the permanent magnet aligned with the coil unit, with the base including a plurality of circuit layers stacked along the axis, with each of the circuit layers having two opposite faces spaced along the axis, and with the coil unit including a plurality of electrically connected coils formed on at least one of the two opposite faces of each of the circuit layers, and with a circuit area formed between two adjacent coils of one of the circuit layers, and with the drive circuit mounted in the circuit area.