Spindle motor having connecting mechanism connecting lead wire and circuit board, and storage disk drive having the same

Abstract

A spindle motor includes a base portion, a rotor hub, a stator, and a circuit board. The base portion preferably includes a through hole and is arranged to spread out radially around a central axis. The rotor hub is arranged above the base portion to rotate about the central axis. The stator is arranged above the base portion, and includes coils each including at least one lead wire. The circuit board is arranged radially outward of the through hole, and arranged on a lower surface of the base portion. The base portion includes a communicating groove arranged to join the through hole and the circuit board to each other. The at least one lead wire of the coils is arranged to pass inside the through hole and the communicating groove to be electrically connected to the circuit board. The through hole is sealed with a sealant.

1 . A spindle motor comprising:
 a base portion including a through hole and arranged to spread out radially around a central axis;   a rotor hub arranged above the base portion to rotate about the central axis; a stator arranged above the base portion, and including coils each including at least one lead wire; and   a circuit board arranged radially outward of the through hole, and arranged on a lower surface of the base portion;   wherein the base portion includes a communicating groove arranged to join the through hole and the circuit board to each other;   the at least one lead wire of the coils is arranged to pass inside the through hole and the communicating groove to be electrically connected to the circuit board; and the through hole is sealed with a sealant.   
     
     
         2 . The spindle motor according to  claim 1 , wherein the base portion includes a recessed portion with a greater diameter than a diameter of the through hole, the recessed portion being arranged at a lower opening portion of a portion of the base portion at which the through hole is defined. 
     
     
         3 . The spindle motor according to  claim 2 , wherein the recessed portion is continuously arranged with the communicating groove; the sealant includes an adhesive; and the sealant is arranged inside the recessed portion and the communicating groove. 
     
     
         4 . The spindle motor according to  claim 1 , wherein the base portion includes a bottom portion in which the through hole is arranged, and a side wall portion arranged to extend upward from an outer circumferential portion of the bottom portion; the bottom portion includes an accommodating portion arranged to be depressed upward and continuous with the communicating groove; and the circuit board includes at least one pad portion arranged to be connected with the at least one lead wire, and arranged inside the accommodating portion. 
     
     
         5 . The spindle motor according to  claim 4 , wherein the at least one lead wire is fixed to the at least one pad portion through a solder; and a total depth of depression of the accommodating portion is greater than a sum of a thickness of the circuit board and a thickness of the solder. 
     
     
         6 . The spindle motor according to  claim 1 , wherein the base portion includes a plurality of through holes arranged therein; and one of the through holes is arranged to have only one of the at least one lead wire passing therethrough. 
     
     
         7 . The spindle motor according to  claim 1 , wherein the base portion includes a plurality of through holes arranged therein; the at least one lead wire is equal in number to the through holes; each of the through holes is arranged to have only one of the at least one lead wire passing therethrough; and each of the at least one lead wire is arranged to extend in substantially the same direction toward the circuit board. 
     
     
         8 . The spindle motor according to  claim 1 , wherein the circuit board includes a first insulating layer, a conductive layer arranged on the first insulating layer to be electrically connected with the at least one lead wire, and a second insulating layer arranged to cover the conductive layer while exposing a portion or portions of the conductive layer; each coil includes a conducting wire and an insulating coating with which the conducting wire is coated; a top end portion of each of the at least one lead wire of the coils includes a coating removed portion where the insulating coating has been removed; and at least the first insulating layer of the circuit board is arranged between the coating removed portion and the base portion. 
     
     
         9 . A disk drive apparatus including a recording disk, the disk drive apparatus comprising: the spindle motor of  claim 1  arranged to rotate the recording disk; an access portion arranged to read and/or write information from or to the recording disk; and a housing defined by a first housing portion and a second housing portion, the first housing portion including the base portion, the housing being arranged to contain the spindle motor and the access portion. 
     
     
         10 . A spindle motor comprising:
 a base portion including a plurality of through holes and arranged to spread out radially around a central axis;   a rotor hub arranged above the base portion to rotate about the central axis; a stator arranged above the base portion, and including coils each including at least one lead wire; and   a circuit board arranged on a lower surface of the base portion, and including at least one pad portion;   wherein the base portion includes a plurality of recessed portions arranged on the lower surface thereof; each of the recessed portions is arranged to have at least one of the through holes arranged therein; and   the at least one lead wire is arranged to pass through the through holes to reach the lower surface of the base portion, and to be electrically connected to the at least one pad portion of the circuit board.   
     
     
         11 . The spindle motor according to  claim 10 , wherein the at least one pad portion is arranged inside the recessed portions. 
     
     
         12 . The spindle motor according to  claim 11 , wherein each of the at least one pad portion includes a pad hole arranged to overlap with a corresponding one of the through holes in an axial direction; each of the at least one lead wire is arranged to reach a lower surface of a separate one of the at least one pad portion through the pad hole thereof, and to be fixed to the pad portion through a solder; and the pad hole is sealed with the solder. 
     
     
         13 . The spindle motor according to  claim 12 , wherein the solder is covered with a sealant. 
     
     
         14 . The spindle motor according to  claim 10 , wherein each of the through holes is arranged to have only one of the at least one lead wire passing therethrough. 
     
     
         15 . The spindle motor according to  claim 10 , wherein each of the recessed portions is arranged to have one of the through holes arranged therein. 
     
     
         16 . The spindle motor according to  claim 10 , wherein each pair of adjacent ones of the through holes includes a wall portion arranged therebetween. 
     
     
         17 . A disk drive apparatus including a recording disk, the disk drive apparatus comprising: the spindle motor of  claim 10  arranged to rotate the recording disk; an access portion arranged to read and/or write information from or to the recording disk; and a housing including a first housing portion and a second housing portion, the first housing portion including the base portion, the housing being arranged to contain the spindle motor and the access portion.