JP2007228681A - Spindle motor for disc drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a disc drive spindle motor thin, and to enhance productivity of an electric apparatus which is made thin. <P>SOLUTION: A hall element 9 opposing a rotor magnet 51 is mounted on a wiring board 7 overlapping a base plate 8 bonded to a bearing housing 3. Overlapping order of the wiring board 7 and the base plate 8 is determined such that the wiring board 7 is arranged oppositely to the rotor magnet 51 while holding the base plate 8 between. The hall element 9 is contained in the hole 73 of the wiring board 7 and buried therein. End-of-winding 43 of a stator 4 is led out through holes 83 and 74 made through the base plate 8 and the wiring board 7 and then soldered to a land on the backside of the wiring board 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a disk drive spindle motor, and more particularly to a disk drive spindle motor used in a mobile device such as a mobile device that is required to be thin.

  In recent years, there is a significant demand for thinning an electrical device that uses a disk as a target medium, such as a DVD recorder or an optical disk drive, in order to improve adaptability to mobile applications. In addition, there is a significant demand for increasing the productivity of thinned electrical equipment.

  On the other hand, a proposal has been made in the past to reduce the thickness of a spindle motor using a Hall element that is a magnetically responsive element for obtaining a rotational position detection signal of a rotor (see, for example, Patent Document 1). . There has also been a proposal intended to facilitate the soldering process of the winding terminal of the spindle motor (see, for example, Patent Document 2).

  According to Patent Document 1, it is shown that a hall element is disposed inside a through hole of a circuit board attached to a housing holding a rotating shaft and a stepped hole formed in the housing. It is suggested that the terminal is soldered to the land on the surface of the wiring board, and it is said that the spindle motor can be thinned by taking such measures. According to Patent Document 2, the printed circuit board is extended to the outside of the rotor, and then the winding terminal drawn out of the rotor is soldered to the land formed on the extended portion of the printed circuit board. It is said that the soldering process of the winding terminal can be facilitated.

  FIG. 3 is a vertical sectional view showing a conventional example of a spindle motor for driving a disk employed in an electric device that uses the disk. In this spindle motor, the rotating shaft 1 is held by a bearing housing 3 fixed to the electrical equipment chassis 100 via a bearing mechanism 2. The stator 4 having the winding 42 mounted on the iron core 41 is fixed to the bearing housing 3, whereas the rotor 5 having the rotor magnet 51 on the rotating shaft 1 side and the rotor 5 are mounted. The turntable 6 is fixed, and a disk (not shown) as a medium is attached to and detached from the turntable 6. Further, the wiring board 7 and the base plate 8 are overlapped, and both are positioned by fitting the convex portion 81 formed of the boss of the base plate 8 and the hole portion 71 on the wiring board 7 side, and the convex portion The parts 81 are joined by caulking. The base plate 8 and the wiring board 7 thus superposed are handled as a laminated integrated body, and after the boss forming the convex portion 8 of the base plate 8 is fitted into the bearing housing 3, the base plate 8 is attached to the electrical equipment chassis. 100 is screwed with a screw 110. Therefore, the overlapping order of the wiring board 7 and the base plate 8 is determined so that the wiring board 7 is close to the rotor magnet 51 and the base plate 8 is positioned on the opposite side of the rotor magnet 51 across the wiring board 7.

  The Hall element (Hall sensor) 9 as a magnetically responsive element is mounted on the wiring board 7 in a state of being mounted on the surface of the wiring board 7 and protruding from the surface by the thickness of the Hall element 9. The hall element 9 faces the rotor magnet 51 with a gap G. The gap G between the Hall element 9 and the rotor magnet 51 is set to an appropriate value determined by the characteristics of the Hall element 9.

On the other hand, a winding terminal 43 drawn from the winding 42 of the stator 4 is soldered to a land formed on the surface of the wiring board 7 superimposed on the base plate 8. Reference numeral 72 denotes a soldering processing unit.
JP-A-9-84299 JP-A-7-298533

  By the way, in the disk drive spindle motor having the structure described with reference to FIG. 3, the facing gap G of the Hall element 9 to the rotor magnet 51 is set to an appropriate value determined by the characteristics of the Hall element 9 as described above. Therefore, it is not appropriate to reduce the thickness of the spindle motor by narrowing the facing gap G. Therefore, if a thin Hall element 9 is used, it is considered that the chassis 100 can be brought close to the rotor magnet 51 by a distance corresponding to the difference in thickness, but the thickness can be reduced. Since the wire diameter and the number of turns of the winding 42 need to be changed, the space A between the wiring board 7 and the stator 4 is narrowed, and the work space for performing the soldering process of the winding terminal 43 is too narrow. Inconvenience arises.

  On the other hand, a method of reducing the thickness by adopting a control system in which the Hall element 9 is erased and a counter electromotive voltage generated by the rotation of the rotor 5 is detected instead, that is, a Hall element-less system, is proposed. ing. However, such a Hall element-less system not only inherently has the problem of great anxiety about start-up stability, but also has the disadvantage that the motor driving IC is expensive.

  The present invention has been made in consideration of the above situation and concerns, and it is possible to change the Hall element as a magnetoresistive element excellent in starting stability to a thin one or to erase the Hall element itself. An object of the present invention is to provide a disk drive spindle motor that can be thinned by changing the mounting form of the Hall elements on the wiring board.

  In addition, the present invention pays attention to the fact that the base plate and the wiring board are handled as a laminated integrated body as described above in the production line of the spindle motor, and takes measures to change the overlapping order of the base plate and the wiring board. This makes it possible to perform the soldering process of the winding terminal in a wide space that does not affect the winding of the stator, and also facilitates measures when a failure occurs in the spindle motor production line An object of the present invention is to provide a spindle motor for driving a disk that can be used for the above.

  In the disk drive spindle motor according to the present invention, the magnetically responsive element facing the rotor magnet with a space is mounted on the wiring board overlapping the base plate fixed to the bearing housing holding the rotor rotation shaft. . Then, after the magnetically responsive element is accommodated in the hole formed in the wiring board and embedded in the wiring board, an appropriate value determined by the characteristic of the magnetic responsive element, the distance between the rotor magnet and the magnetically responsive element is determined. It is stipulated in.

  With this configuration, the magnetically responsive element does not protrude from the surface of the wiring board, or even if it protrudes, its protruding height is reduced to match the embedding width of the magnetic responsive element with respect to the wiring board. Is set to an appropriate value determined by the characteristics of the magnetically responsive element, the overall height of the spindle motor is reduced, and its thinning is promoted.

  In the present invention, the order of overlap between the wiring board and the base plate is determined so that the wiring board is disposed on the opposite side of the rotor magnet across the base plate, and the pace plate is provided with the magnetically responsive element on the wiring board. A portion covering the mounting portion of the stator is removed, and the winding end of the stator is drawn out through a through-hole formed in the base plate and the wiring board and soldered to a land on the back side of the wiring board. It is desirable to adopt the configuration of In order to determine the overlapping order of the wiring board and the base plate so that the wiring board is arranged on the opposite side of the rotor magnet with the base plate in between, the wiring board and the base plate that are handled as a laminated monolith on the production line are arranged. In contrast to the case described with reference to FIG. 3, it is only necessary to turn it upside down and fit it into the bearing housing. Therefore, there is no possibility that productivity is lowered by taking this measure. Even if such measures are taken, the detection sensitivity of the magnetically responsive element may be adversely affected by the baseplate because the baseplate is omitted at the portion of the wiring board that covers the mounting location of the magnetically responsive element. Nor.

  In addition, by adopting a configuration in which the winding end of the stator is pulled out through a through-hole portion formed in the base plate and the wiring board and soldered to the land on the back side of the wiring board, the wiring board Since the land is separated from the stator winding by the base plate, the soldering iron can be operated in a wide space that does not adversely affect the stator winding during the soldering process. It helps to easily remove the soldered winding terminal. In addition, this is useful for facilitating operations such as repair and replacement of the magnetic actuator mounted on the wiring board when a failure occurs in the production line of the spindle motor.

  In the present invention, it is possible to adopt a configuration in which the wiring board and the base plate are screwed to the electrical equipment chassis.

  In the spindle motor for driving a disk according to the present invention, the magnetically responsive element facing the rotor magnet with a gap protrudes from the surface of the wiring board overlapping the base plate fixed to the bearing housing holding the rotor rotating shaft. In the disk drive spindle motor in which the base plate is screwed to the electrical equipment chassis, the overlapping order of the wiring board and the base plate is set on the opposite side of the rotor magnet across the base plate. The pace plate is removed at a portion covering the mounting location of the magnetic actuator on the wiring board, and the magnetic actuator is formed in a hole formed in the wiring board. After being housed and embedded in the wiring board, the rotor magnet and its The distance between the air responsive element and the air responsive element is set to an appropriate value determined by the characteristics of the magnetic responsive element, and the winding end of the stator is drawn out through the through-hole portion formed in the base plate and the wiring board. The present invention is further embodied by adopting a configuration in which an opening that is soldered to a land on the back side of the substrate and that exposes a soldered portion of the winding terminal is formed in the base plate. The effect | action of this invention is demonstrated in detail with reference to embodiment mentioned later.

  As described above, according to the present invention, the Hall element is mounted on the wiring board without changing the thickness of the magnetic responsive element having excellent start-up stability to a thin one or erasing the magnetic responsive element itself. It is possible to reduce the thickness of the spindle motor for driving the disk, and hence to reduce the thickness of the electrical equipment that employs the spindle motor. Therefore, it can be said that the invention is extremely useful in making a DVD player, an optical disk drive, etc. thinner and making them mobile. In addition, in the case where the overlapping order of the base plate and the wiring board is changed, it is possible to perform the soldering process of the winding terminal in a wide space that does not adversely affect the winding of the stator. There is also an advantage that measures such as repair and replacement of the magnetically responsive element when a defect occurs on the production line can be easily performed.

  FIG. 1 is a longitudinal sectional view of a spindle motor for driving a disk employed in an electric device that uses a disk according to an embodiment of the present invention.

  In the spindle motor of this embodiment, the rotating shaft 1 is held by the bearing housing 3 fixed to the electrical equipment chassis 100 via the bearing mechanism 2, and the stator 4 having the winding 42 mounted on the iron core 41. The rotor 5 having the rotor magnet 51 and the turntable 6 mounted on the rotor 5 are fixed to the rotating shaft 1 side, while being fixed to the bearing housing 3. The point that a disk as a medium is attached and detached is the same as that described with reference to FIG.

  The wiring substrate 7 and the base plate 8 are overlapped with each other, and both are positioned by fitting the convex portion 81 formed of the boss of the base plate 8 and the hole portion 71 on the wiring substrate 7 side. Reference is also made to FIG. 3 to describe the fact that the base plate 8 and the wiring board 7 that are superposed on each other are handled as a laminated unit in the production line of the spindle motor. It is the same as that.

  However, in this embodiment, when the boss forming the convex portion 8 of the base plate 8 is fitted to the bearing housing 3, the boss is attached to the bearing housing 3 in such a posture that the base plate 8 is positioned above the wiring board 7. By fitting, the overlapping order of the wiring board 7 and the base plate 8 is determined in such an order that the base plate 8 is close to the rotor magnet 51 and the wiring board 7 is located on the opposite side of the rotor magnet 51 with the base plate 8 interposed therebetween. is there. That is, in this embodiment, the laminated integrated body of the base plate 8 and the wiring board 7 is turned upside down with respect to the case of FIG. The base plate 8 is screwed to the electrical equipment chassis 100 using screws 110.

  Further, the Hall element 9 as a magnetically responsive element is accommodated in the hole portion 73 formed by a square hole formed in the wiring board 7 so that the whole is embedded in the wiring board 7, and the pace plate 8 is attached to the wiring board 7. The Hall element 9 is opposed to the rotor magnet 51 by removing it at a portion covering the mounting portion of the Hall element 9. Reference numeral 82 denotes a missing portion of the base plate 8. The spacing G of the Hall element 9 with respect to the rotor magnet 51 is set to an appropriate value determined by the characteristics of the Hall element 9. By adopting this configuration, compared to the conventional example described with reference to FIG. 3, a length corresponding to the thickness of the Hall element 9 is set despite the fact that the opposing gap G of the Hall element 9 with respect to the rotor magnet 51 is set to be the same. As a result, the height H of the spindle motor is lower than the height H1 of the spindle motor shown in FIG.

  On the other hand, the winding terminal 43 drawn out from the winding 42 of the stator 4 is drawn out to the lower side of the wiring board 7 through the through holes 83 and 74 formed in the base plate 8 and the wiring board 7. Soldered to the backside land. Reference numeral 75 denotes a soldering processing unit. In this embodiment, the soldering processing unit 75 is configured to be stored in the opening 120 opened in the electrical equipment chassis 100 and exposed from the inside of the opening 120 to the outside.

  In this way, by soldering the winding terminal 43 to the land on the back side of the wiring board 7, the soldering point is shielded from the winding 42 by the base plate 8. There is no possibility of a situation where the winding 42 is damaged due to contact with the coil, and as a result, a situation where a defective product is not generated due to the damage of the winding on the production line does not occur, which increases mass productivity. To help. Further, when a defect is found in the Hall element 9 after the spindle motor is assembled, for example, the winding 43 is removed from the soldering processing unit 75 and the spindle motor is removed from the electrical equipment chassis 100. Thus, the Hall element 9 can be exposed, and then the Hall element 9 can be easily repaired or replaced, and the productivity can be increased accordingly.

  FIG. 2 shows another embodiment. In this embodiment, the overlapping order of the wiring board 7 and the base plate 8 is set so that the wiring board 7 is close to the rotor magnet 51, and the base plate 8 sandwiches the wiring board 7 and is opposite to the rotor magnet 51, as in FIG. The hall element 9 is accommodated in a hole 73 formed by a square hole formed in the wiring board 7 so as to be embedded in the wiring board 7. Other configurations are the same as those in FIG.

  Even by adopting this configuration, the opposing distance H of the Hall element 9 to the rotor magnet 51 is set to be equal to the thickness of the Hall element 9 compared to the conventional example described in FIG. The height H of the spindle motor is lower than the height H1 of the spindle motor in FIG.

  In FIG. 1 to FIG. 3, the same parts are denoted by the same reference numerals for convenience of explanation.

1 is a longitudinal sectional view of a disk drive spindle motor according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the spindle motor for disk drive which concerns on other embodiment. It is a longitudinal cross-sectional view of a conventional spindle motor for driving a disk.

Explanation of symbols

1 Rotating shaft (Rotor rotating shaft)
3 Bearing Housing 4 Stator 7 Wiring Board 8 Base Plate 9 Hall Element (Magnetic Response Element)
43 Winding terminal 51 Rotor magnet 73 Hole 74, 83 Through hole 100 Electrical equipment chassis 120 Opening H Opposite spacing

Claims (4)

A magnetically responsive element facing the rotor magnet with a gap is mounted in a protruding state on the surface of the wiring board that overlaps the base plate fixed to the bearing housing holding the rotor rotating shaft, and the base plate is electrically In the spindle motor for disk drive that is screwed to the equipment chassis,
The overlapping order of the wiring board and the base plate is changed so that the wiring board is disposed on the opposite side of the rotor magnet with the base plate interposed therebetween, and the pace plate is used to change the mounting position of the magnetic actuator on the wiring board. The magnetically responsive element is housed in a hole formed in the wiring board and embedded in the wiring board, and the opposing distance between the rotor magnet and the magnetic responsive element is set to the gap. It is set to an appropriate value determined by the characteristics of the magnetic actuator,
A stator winding terminal is pulled out through a through hole formed in the base plate and the wiring board and soldered to a land on the back side of the wiring board, and the winding terminal is soldered to the base plate. A spindle motor for driving a disk, wherein an opening for exposing a portion is opened. In the disk drive spindle motor in which the magnetically responsive element facing the rotor magnet with a space is mounted on the wiring board that is overlapped with the base plate fixed to the bearing housing holding the rotor rotation shaft,
The magnetoresistive element is accommodated in a hole formed in the wiring board and embedded in the wiring board, and the facing distance between the rotor magnet and the magnetic actuating element is set to an appropriate value determined by the characteristics of the magnetic responding element. A disk drive spindle motor characterized by the above. The order of overlap between the wiring board and the base plate is determined so that the wiring board is disposed on the opposite side of the rotor magnet across the base plate, and the pace plate defines the mounting position of the magnetoresistive element on the wiring board. The covering portion is omitted, and the winding end of the stator is drawn out through a through hole formed in the base plate and the wiring board and soldered to a land on the back side of the wiring board. A spindle motor for driving a disk as described in 1. 4. The disk drive spindle motor according to claim 2, wherein the wiring board and the base plate are screwed to the electrical equipment chassis.

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