Slim Fan

Abstract

A slim fan includes a housing, an impeller, and a stator unit. The housing includes a bottom board. The bottom board includes an inner face and an outer face. The bottom board includes at least one receiving space located between the inner face and the outer face. An impeller is rotatably mounted in the housing. A stator unit is mounted in the housing. The stator unit includes a circuit board, a coil unit, and at least one electronic element. The coil unit and the at least one electronic element are mounted on the circuit board. The at least one electronic element extends into the at least one receiving space.

What is claimed is: 
     
         1 . A slim fan comprising:
 a housing including a bottom board, wherein the bottom board includes an inner face and an outer face, wherein the bottom board includes at least one receiving space located between the inner face and the outer face;   an impeller rotatably mounted in the housing; and   a stator unit mounted in the housing, wherein the stator unit includes a circuit board, a coil unit, and at least one electronic element, wherein the coil unit and the at least one electronic element are mounted on the circuit board, and wherein the at least one electronic element extends into the at least one receiving space.   
     
     
         2 . The slim fan as claimed in  claim 1 , wherein before the stator unit and the housing are assembled, each of a maximum axial height of the bottom board in an axial direction of the impeller and a maximum axial height of the stator unit in the axial direction of the impeller is not larger than 1.1 mm, and wherein a sum of the maximum axial height of the bottom board and the maximum axial height of the stator unit is larger than 1.1 mm. 
     
     
         3 . The slim fan as claimed in  claim 2 , wherein after the stator unit and the housing are assembled, the stator unit and the bottom board have an assembled axial height not larger than 1.1 mm. 
     
     
         4 . The slim fan as claimed in  claim 1 , wherein the at least one receiving space is located within a maximum diametric range of the stator unit. 
     
     
         5 . The slim fan as claimed in  claim 1 , wherein the coil unit is formed on the circuit board by etching or electrocasting. 
     
     
         6 . The slim fan as claimed in  claim 1 , wherein the circuit board includes a plurality of grooves, and wherein the coil unit extends into the plurality of grooves. 
     
     
         7 . The slim fan as claimed in  claim 1 , wherein the at least one receiving space includes a through-hole extending through the bottom board. 
     
     
         8 . The slim fan as claimed in  claim 7 , wherein the at least one receiving space includes a first chamber and a second chamber, wherein the at least one electronic element extends into the first chamber, and wherein a spacer is mounted in the second chamber. 
     
     
         9 . The slim fan as claimed in  claim 8 , wherein a diametric range of the first chamber in a diametric direction of the impeller is smaller than a diametric range of the second chamber in the diametric direction of the impeller. 
     
     
         10 . The slim fan as claimed in  claim 8 , wherein the spacer does not protrude beyond the outer face of the bottom board. 
     
     
         11 . The slim fan as claimed in  claim 1 , wherein the at least one receiving space includes a blind hole in the bottom board. 
     
     
         12 . The slim fan as claimed in  claim 1 , wherein the impeller includes a hub and a plurality of blades, wherein the plurality of blades is annularly disposed on an outer periphery of the hub, wherein each of the plurality of blades includes an inner edge and an outer edge, wherein a blade rotational range is formed between the inner edges and the outer edges of the plurality of blades, and wherein the stator unit is not located within the blade rotational range in an axial direction of the impeller.