CN103280909B - Spindle motor and the record disc drive unit with this spindle motor - Google Patents

Abstract

The present invention provides a spindle motor and a recording disc drive device having the same. The spindle motor includes: a base that includes a plurality of through holes and expands radially around a central axis; a rotor hub that is located on an upper side of the base and rotates around the central axis; and a stator that is located on an upper side of the base. and including a coil having lead wires; and a circuit substrate, which is located on the lower surface of the base, the base has a plurality of recesses on the lower surface, and at least one of the through holes is arranged in each of the recesses, The lead-out line reaches the lower surface of the base through the through hole, and is electrically connected to the pad portion of the circuit board.

Description

Spindle motor and recording disk drive device having the same

This application is based on a divisional application of an invention patent application titled "Spindle Motor and Recording Disk Drive Device Having the Spindle Motor" with the filing date of December 31, 2010 and the application number of 201010620121.8.

technical field

The present invention relates to a spindle motor and a recording disk drive device having the same.

Background technique

In the disk drive motor disclosed in JP 2000-209804 A, the lead wires of the coils are passed through the lead wire holes of the motor bracket to be electrically connected to the flexible circuit board. The lead-out holes are closed by the flexible circuit board. Attach the flexible circuit board to the bottom surface of the motor bracket with an adhesive.

However, as in JP 2000-209804 A, in the case of a structure in which the bottom surface of the motor bracket is soldered, it is necessary to plan the bottom surface of the motor bracket in consideration of the bonding area of the circuit board and the height of the solder. However, there may be a problem that the thickness of the planed portion becomes thinner and the rigidity of the motor bracket decreases.

Contents of the invention

An exemplary spindle motor of the present invention includes a base, a rotor hub, a stator, and a circuit substrate. The base includes a plurality of through holes that expand radially around the central axis. The rotor hub is located on the upper side of the base and rotates around the central axis. The stator is located on the upper side of the base and includes coils with lead wires. The circuit substrate is located on the lower surface of the base. The base includes a plurality of recesses. At least one through hole is arranged in each concave portion. The lead wire reaches the lower surface of the base through the through hole, and is electrically connected to the pad portion of the circuit board.

According to the present invention, the concave portion and the communication groove are arranged on the lower surface of the base by planing the portion corresponding to the lead-out line on the lower surface of the base. Therefore, compared with the conventional structure, the area to plan the base can be reduced, and the rigidity of the base can be improved.

In addition, a plurality of recesses are arranged on the lower surface of the base by planing a portion corresponding to the lead-out line on the lower surface of the base. Therefore, compared with the conventional structure, the area to plan the base can be reduced, and the rigidity of the base can be improved.

The above and other features, elements, steps, characteristics and advantages of the present invention can be more clearly understood from the following detailed content of preferred embodiments of the present invention described with reference to the accompanying drawings.

Description of drawings

1 is a cross-sectional view showing the structure of a hard disk drive device having a spindle motor according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a spindle motor.

FIG. 3 is a plan view showing the structure of a spindle motor.

4 is a cross-sectional view showing the structure of a circuit board.

FIG. 5 is a diagram for explaining a soldering process of lead wires.

Fig. 6 is a plan view for explaining a step of connecting lead wires to a circuit board.

FIG. 7 is a plan view showing a modified example of Embodiment 1. FIG.

8 is a plan view showing the configuration of a spindle motor according to Embodiment 2. FIG.

9 is a plan view showing the configuration of a spindle motor according to Embodiment 3. FIG.

FIG. 10 is a plan view showing Modification 1 of Embodiment 3. FIG.

FIG. 11 is a plan view showing Modification 2 of Embodiment 3. FIG.

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. In addition, the following embodiments are only preferable examples in nature, and are not intended to limit the scope of the present invention and its applications or uses.

FIG. 1 is a cross-sectional view showing the structure of a hard disk drive device having a spindle motor according to Exemplary Embodiment 1 of the present invention. As shown in FIG. 1 , the hard disk drive device 1 includes a disc-shaped recording disk 11 on which information is recorded, an access unit 12 , a spindle motor 10 (hereinafter referred to as “motor 10 ”), and a housing 13 . The access unit 12 reads and/or writes information to the recording disk 11 . The motor 10 rotates the recording disk 11 . The casing 13 accommodates the recording disk 11 , the access unit 12 and the motor 10 . The motor 10 is preferably a three-phase brushless motor.

In addition, in this specification, the upper side along the direction of central axis J1 in a drawing is described as "upper side", and the lower side in a drawing is described as "lower side." In addition, in the description of the illustrated embodiment, when the positional relationship and direction of each component are described from top to bottom, left to right, the positional relationship and direction in the drawings are always shown, and the positional relationship and direction when incorporated into an actual device are not shown. positional relationship and orientation.

The case 13 includes a first case portion 13 a and a substantially plate-shaped second case portion 13 b covering an opening of the first case portion 13 a. The first case part 13a includes an opening in the upper part, and the motor 10 and the access part 12 are arranged on the inner bottom surface. The internal space S of the casing 13 is preferably a clean space with very little or no dust. In the inner space S intervening gas is present. As gas, air, helium, etc. are mentioned, for example.

The recording disk 11 is placed on the upper side of the motor 10 and supported on the motor 10 via the clamping member 14 and the ring-shaped spacer 15 .

The access unit 12 includes a magnetic head 12 a , an arm 12 b supporting the magnetic head 12 a , and a magnetic head moving mechanism 16 . The magnetic head 12a approaches the recording disk 11 and magnetically reads and/or writes information. The magnetic head moving mechanism 16 moves the magnetic head 12a relative to the recording disk 11 and the motor 10 by moving the arm 12b. Thus, the magnetic head 12a accesses a necessary position on the recording disk 11 in a state close to the rotating recording disk 11, and reads and/or writes information.

FIG. 2 is a cross-sectional view showing the structure of a spindle motor. As shown in FIG. 2 , the motor 10 is an outer rotor type motor and includes a rotor portion 20 and a stator portion 30 .

The rotor part 20 is rotatably supported with respect to the stator part 30 by the hydrodynamic pressure bearing 25 using a fluid. As a fluid, gas, a liquid, etc. are mentioned, for example. The rotor unit 20 includes a rotor hub 21 , a shaft 22 arranged at the center of the rotor hub 21 , and a rotor magnet 23 fixed to the rotor hub 21 and arranged around the central axis J1 .

The shaft 22 is fixed to the center of the rotor hub 21 by press-fitting, bonding, or the like.

The lower front end portion of the shaft 22 includes a substantially annular flange portion 22a. The rotor magnet 23 is an annular magnet magnetized with multiple poles, and generates a rotational torque around the center axis J1 between the rotor magnet 23 and the stator 40 described later.

The stator part 30 includes a base plate 31 , a stator 40 , and a thrust yoke 33 . The bottom plate 31 includes a hole portion 31a and a clamping portion 31b. The stator 40 is disposed on the outer periphery of the holding portion 31b. Thrust yoke 33 is arranged on base plate 31 to face rotor magnet 23 . A magnetic attraction force is generated between the thrust yoke 33 and the rotor magnet 23 , and the rotor portion 20 receives a force toward the lower side (the stator portion 30 side).

The bottom plate 31 is made of aluminum alloy or the like, and constitutes a part of the casing 13 of the hard disk drive device 1 in which the motor 10 is disposed. Mechanisms such as the access unit 12 (see FIG. 1 ) are arranged on the bottom plate 31 . The cylindrical sleeve part 50 is arrange|positioned in the hole part 31a. The stator 40 includes an iron core 41 and a coil 42 wound around the iron core 41 .

Preferably, the sleeve portion 50 includes a substantially cylindrical sleeve 51 centered on the central axis J1 and a substantially disk-shaped sealing cap 52 closing the lower opening of the sleeve 51 . The sleeve 51 and the sealing cap 52 are made of stainless steel, for example.

The lower portion of the sleeve 51 includes a stepped portion 51a recessed upward. The seal cap 52 is fixed to the sleeve 51 with an adhesive or the like so as to close the stepped portion 51 a. The flange portion 22a of the shaft 22 is housed in the stepped portion 51a.

The communication hole 51 b penetrating in the axial direction is located radially outside the central axis J1 of the sleeve 51 . The communication hole 51 b communicates with the gap between the stepped portion 51 a at the lower portion of the sleeve 51 and the sealing cover 52 .

In the sleeve portion 50, between the inner peripheral surface of the sleeve 51 and the outer peripheral surface of the shaft 22, between the upper surface and the outer peripheral surface of the sleeve 51 and the flange portion 22a, and between the upper surface of the seal cover 52 and the outer peripheral surface of the shaft 22, A slight gap is formed between the lower surfaces of the flange portions 22a. Lubricant is continuously filled as a fluid in minute gaps. In the motor 10 , the bearing mechanism 25 is constituted by the sleeve 51 , the seal cover 52 , the shaft 22 and lubricant. Further, the shaft 22 is supported without contacting the sleeve portion 50 through the lubricant. The rotor unit 20 and the recording disk 11 held on the rotor unit 20 rotate with respect to the stator unit 30 with high precision and low noise. In addition, lubricating oil is preferably used as the lubricant.

As shown in FIG. 3 , the lower surface of the bottom plate 31 includes a thick base portion 34 expanding radially around the center axis J1 . The base portion 34 includes four through holes 35 corresponding to the four lead wires 43 (W-phase, V-phase, U-phase, common wire) pulled out from the coil 42 of the stator 40 . An insulating bush 45 is disposed on the through hole 35 . In addition, it is preferable that only one lead wire 43 passes through one through hole 35 . Therefore, the work of soldering and connecting the lead wires 43 to the circuit board 60 can be easily performed. The insulating bush 45 is fixed to the inner peripheral surface of the base portion 34 constituting the through hole 35 by a method such as press fitting. The insulating bush 45 may also be arranged with a gap between the inner peripheral surface of the base 34 . Furthermore, it is preferable that the coil 42 and the lead wire 43 are constituted by a single member.

When drawing a plurality of lead wires from one through hole, it is necessary to select an appropriate lead wire for each phase of the circuit board, which may lower workability. On the other hand, in the illustrated embodiment, since only one lead wire passes through one through hole 35, the lead wire 43 corresponding to each phase of the circuit board 60 can be easily grasped, and the soldering operation is facilitated. In addition, the common line among the lead-out lines 43 is constituted by combining three lines into one, and is regarded as one lead-out line 43 .

The lower opening portion of the base portion 34 of the through hole 35 includes a concave portion 36 having a larger diameter than the through hole 35 . Specifically, the concave portion 36 has a shape whose diameter gradually increases downward. The through hole 35 is arranged in the concave portion 36 . Between the circumferential direction of each through-hole 35, the wall part 58 which partitions each recessed part 36 is arrange|positioned.

The base portion 34 includes a bottom portion 34 a having a through hole 35 , and a side wall portion 34 b extending upward from the outer peripheral portion of the bottom portion 34 a. The bottom 34 a includes a receiving portion 37 and a communication groove 38 . The housing portion 37 is located radially outward of the through hole 35 and is recessed upward. The communication groove 38 connects the concave portion 36 and the storage portion 37 . It is preferable that the communication groove 38 is configured to be substantially on the same plane as the recessed portion 36 and the receiving portion 37 . The storage portion 37 extends in the circumferential direction. By arranging the storage portion 37 at a position radially outward of the through hole 35, compared with the case where the storage portion is disposed near the through hole, the area of the planed bottom can be reduced, and the base portion 34 can be restrained from being cut. rigidity decreased.

In addition, by arranging the housing portion 37 at a relatively thick portion of the bottom portion 34a, it is possible to suppress a reduction in the rigidity of the base portion 34 . In the embodiment, for example, a thicker portion overlaps the thrust yoke 33 in the axial direction.

The concave portion 36 and the communication groove 38 are arranged on the lower surface of the base portion 34 by planing the portion on the lower surface of the base portion 34 corresponding to the lead-out line 43 . Therefore, compared with the conventional structure, the area of the planed base 34 can be reduced, and the rigidity of the base 34 can be improved. In addition, the concave portion 36 preferably has a minimum size that can smoothly pull the lead wire 43 out of the through hole 35 , and the area of the planed base portion 34 can be further reduced by using the concave portion 36 of the minimum size.

Preferably, the storage portion 37 includes an inclined portion 37 a inclined upward in the circumferential direction of the base portion 34 . The recess depth of the storage portion 37 on the side where the common wire is arranged is deeper than the recess depth of the storage portion 37 on the side where the other lead wire 43 is arranged. Since the common wire is three wires combined into one wire, although it is regarded as one lead wire 43 , its diameter is larger than that of other lead wires 43 . The exposure of the common wire from the lower surface of the base part 34 can be prevented by configuring the recessed depth of the storage part 37 from which the common wire is pulled out to be deep.

In addition, it is preferable that the surface of the bottom plate 31 including the concave portion 36 and the communication groove 38 include an electrodeposition coating film. The electrodeposited coating film has a thickness of about several μm to obtain insulation.

A flexible circuit board 60 (hereinafter, referred to as “circuit board 60 ”) is disposed on the housing portion 37 . Specifically, the pad portion 65 connected to the lead wire 43 of the coil 42 in the circuit board 60 is arranged in the housing portion 37 .

As shown in FIG. 4 , the circuit board 60 includes an adhesive layer 61 , a first insulating layer 62 , a conductive layer 63 and a second insulating layer 64 . The first insulating layer 62 is located on the adhesive layer 61 . The conductive layer 63 is located on the first insulating layer 62 and is electrically connected to the lead wire 43 . The second insulating layer 64 covers other portions of the conductive layer 63 with a part of the conductive layer 63 exposed. The pad portion 65 includes a part of the conductive layer 63 . The circuit board 60 is arranged along the side wall portion 34 b and the lower surface of the bottom plate 31 . The pad portion 65 is arranged in the housing portion 37 . Preferably, the circuit board 60 is attached to the lower surface of the bottom plate 31 via an adhesive layer 61 . It is preferable that the first and second insulating layers 62 and 64 are made of, for example, polyimide or the like. It is preferable that the conductive layer 63 is made of, for example, copper foil or the like.

Here, as shown in FIG. 3 , the first insulating layer 62 and the second insulating layer 64 near the pad portion 65 corresponding to the W phase and the common line of the lead wire 43 of the coil 42 include protrusions extending toward the through hole 35 . 60a. The protruding portion 60 a is preferably arranged in the communication groove 38 . The protruding portion 60 a is disposed between the uncoated portion 44 of the lead wire 43 and the bottom plate 31 . The first and second insulating layers 62 , 64 located between the film-removed portion 44 of the lead wire 43 and the bottom plate 31 can prevent the lead wire 43 from contacting and electrically connecting to the bottom plate 31 , that is, short circuit.

In addition, it is preferable that the surface of the bottom plate 31 constituting the concave portion 36 and the communication groove 38 is covered with the above-mentioned electrodeposition coating film. By electrodepositing the coating film, it is possible to prevent the lead wires from being in contact with the base plate 31 to be electrically connected to the base plate 31 . In particular, by covering the surface of the bottom plate 31 constituting the communication groove 38 with the electrodeposition coating film, the first and second insulating layers 62 , 64 and the electrodeposition coating film are positioned between the film removal portion 44 and the bottom plate 31 . Therefore, it is possible to further prevent the lead wire 43 from being electrically connected to the bottom plate 31 .

In addition, the portion of the bottom plate 31 constituting the housing portion 37 is also covered with an electrodeposited coating film. Moreover, the protrusion part 60a may consist only of the 1st insulating layer 62, and may consist only of the 2nd insulating layer 64. As shown in FIG.

The coil 42 of the stator 40 includes a lead wire 43a and an insulating coating 43b covering the lead wire 43a. The tip portion of the lead wire 43 of the coil 42 includes a film-removed portion 44 from which the insulating film 43b has been removed. The film removal part 44 contains a solder film. The lead wire 43a exposed by removing the insulating film 43b is covered with a solder film in a soldering step described later.

Lead wires 43 pass through insulating bushing 45 disposed in through hole 35 of base 34 and communication groove 38 , and extend toward circuit board 60 in substantially the same direction (in FIG. 3 , a diagonally downward direction to the right). With such a configuration, it is possible to efficiently perform wiring work for the lead wires 43 . While holding the four lead wires 43 drawn out to the lower surface of the base 34 using a jig (not shown), the jig is moved obliquely downward toward the circuit board 60 side. With such a structure, the four lead wires 43 can be bent in the same direction at the same time and arranged in the communication groove 38, thereby improving work efficiency.

The lead wires 43 are soldered to the land portions 65 of the circuit board 60 to be electrically connected to the circuit board 60 . Here, the recessed depth of the housing portion 37 is preferably greater than the sum of the thickness of the circuit board 60 and the thickness of the solder 48 (see FIG. 1 ). Therefore, the solder 48 hardly protrudes from the lower surface of the base 34 .

The through hole 35 is sealed by a sealing material 55 located in the recess 36 and the communication groove 38 . Preferably, the sealing material 55 is a thermosetting adhesive. In the through hole 35 , the concave portion 36 and the communicating groove 38 , the sealing material 55 is positioned so as not to move the lead wire 43 . Here, it is preferable that the concave portion 36 has a shape whose diameter gradually increases downward. With this configuration, when the sealing material 55 is located in the recessed portion 36 , the sealing material 55 is easily gathered at the lower opening of the through hole 35 . In addition, for the sealing material 55 , for example, various adhesives such as ultraviolet curable adhesives may be used instead of thermosetting adhesives. In addition, as long as airtightness can be obtained, a sealing material other than an adhesive may be used. For example, a sealing material other than an adhesive that is liquid or gel in an applied state may be used.

In addition, in FIG. 3 , although the sealing material 55 is drawn to be located only in the W-phase through-hole 35 , the concave portion 36 and the communication groove 38 in order to easily see the lead-out line 43 , in fact, the sealing material 55 is located in all the through-holes. 35, the recess 36 and the communication groove 38.

Since the circuit board 60 is disposed in the housing portion 37 radially outside the through hole 35 , the circuit board 60 does not prevent the sealing material 55 from sealing the through hole 35 when the through hole 35 is sealed. Furthermore, airtightness can be obtained by sealing the through hole 35 with the sealing material 55 . Therefore, it is possible to prevent air and the like from entering and exiting the housing 13 of the hard disk drive device 1 through the through hole 35 . In particular, it is possible to prevent gas or the like present in the housing 13 of the hard disk drive device 1 from leaking through the through hole 35 . In addition, in the present embodiment, helium gas exists in the housing 13 , and since helium gas has a smaller molecular weight than air, it tends to leak from the through hole 35 . However, according to the configuration of the present embodiment, helium gas can be prevented from leaking from the through hole 35 .

Next, a procedure for electrically connecting the lead wire 43 of the stator 40 to the circuit board 60 will be described with reference to FIGS. 5 and 6 . First, the adhesive layer 61 of the circuit board 60 is attached to the lower surface of the bottom plate 31 . Then, a substantially cylindrical insulating bush 45 is press-fitted into the through hole 35 of the bottom plate 31 .

FIG. 5 is a diagram for explaining a soldering process of lead wires. As shown in FIG. 5( a ), four lead wires 43 having different lengths are pulled out from the ends of the coils 42 of the stator 40 . In FIG. 5( a ), it is preferable that the lengths of the lead wires 43 become shorter in the order of W-phase, V-phase, U-phase, and common wires. By changing the length of each lead wire 43, it is possible to easily grasp the lead wire 43 corresponding to each of the circuit boards 60, and it is easy to perform wiring work and/or soldering work.

As shown in FIG. 5( b ), each lead wire 43 is immersed in a solder tank 70 in which molten solder liquid 71 is stored. The insulating film 43b of the part of the lead wire 43 immersed in the solder liquid 71 is melted, and the lead wire 43a is exposed. More specifically, in each lead wire 43, the length of the insulating film 43b remaining without melting is almost equal, and the length of the lead wire 43a becomes shorter in the order of W phase, V phase, U phase, and common wire. Thereafter, as shown in FIG. 5( c ), the stator is lifted upward, whereby the tip portion of each lead wire 43 includes a film-removed portion 44 in which the lead wire 43 a is covered with a solder film.

Next, as shown in FIG. 6 , the lead wires 43 are passed through the through holes 35 of the bottom plate 31 one by one for each hole, and the stator 40 is fixed to the clamping portion 31 b of the bottom plate 31 by pressing or the like. Then, while holding the four lead wires 43 pulled out from the lower surface of the base portion 34 of the chassis 31 with the jig, the jig is moved toward the circuit board 60 side obliquely downward to the right. Then, the four lead wires 43 are bent in substantially the same direction at almost the same time and arranged in the communication groove 38 .

The film-removed portion 44 immediately after the lead wire 43 is bent is exposed from the pad portion 65 of the circuit board 60 . Therefore, after soldering the film-removed part 44 of the lead wire 43 to the land part 65 , the tip part of the film-removed part 44 exposed from the land part 65 is cut off.

Then, an adhesive is applied to the through-hole 35 , the concave portion 36 and the communication groove 38 , and the adhesive is heated to be cured. The airtightness inside the casing 13 is improved by the cured adhesive. In addition, in the through hole 35 , the concave portion 36 and the communicating groove 38 , the cured adhesive is positioned so as not to move the lead wire 43 . Through the above, the wiring work of the lead wires 43 is completed.

FIG. 7 is a plan view showing a modified example of the first embodiment. As shown in FIG. 7 , the lower surface of the bottom plate 31 includes a thick base portion 34 expanding radially around the central axis J1 . The base portion 34 includes four through holes 35 corresponding to the four lead wires 43 (W-phase, V-phase, U-phase, common wire) pulled out from the coil 42 of the stator 40 . Preferably: only one lead wire 43 passes through one through hole 35 .

The lower opening portion of the base portion 34 of the through hole 35 includes a concave portion 36 having a larger diameter than the through hole 35 . The through hole 35 is arranged in the recess 36 . Between the circumferential direction of each through-hole 35, the wall part 58 which partitions each recessed part 36 is arrange|positioned.

The base portion 34 includes a bottom portion 34 a having a through hole 35 , and a side wall portion 34 b extending upward from the outer peripheral portion of the bottom portion 34 a. The bottom portion 34 a includes a communication groove 38 continuing to the concave portion 36 and the side wall portion 34 b of the through hole 35 .

The circuit substrate 60 is arranged at the lower surface of the base plate 31 on the radially outer side than the base portion 34 .

Each lead wire 43 extends toward the circuit board 60 through the through-hole 35 and the communication groove 38 of the base 34 . The lead wires 43 are soldered to the pad portions 65 of the circuit board 60 to be electrically connected to the circuit board 60 .

The through hole 35 is sealed by a sealing material 55 located in the recess 36 and the communication groove 38 . The sealing material 55 contains a thermosetting adhesive. In the through hole 35 , the concave portion 36 and the communicating groove 38 , the sealing material 55 is positioned so as not to move the lead wire 43 .

Since the circuit board 60 is arranged radially outward from the base 34 , the area of the planed bottom can be reduced more than when the storage portion for accommodating the circuit board is arranged on the base. In addition, the decrease in the rigidity of the base portion 34 can be further suppressed.

The concave portion 36 and the communication groove 38 are arranged on the lower surface of the base portion 34 by planing the portion corresponding to the lead-out line 43 on the lower surface of the base portion 34 . Therefore, compared with the conventional structure, the area of the planed base 34 can be reduced, and the rigidity of the base 34 can be improved. In addition, it is preferable that the recessed portion 36 has a minimum size that can smoothly pull the lead wire 43 out of the through-hole 35 , and this structure can further reduce the area of the planed base portion 34 .

FIG. 8 is a plan view showing the configuration of a spindle motor according to Embodiment 2. FIG. The basic structure is almost the same as that of Embodiment 1, and the same reference numerals are assigned to the same parts as in Embodiment 1, and only different parts will be described. As shown in FIG. 8 , the lower surface of the bottom plate 31 includes a thick base portion 34 expanding radially around the center axis J1 . Preferably, the base portion 34 includes four through holes 35 corresponding to the four lead wires 43 (W-phase, V-phase, U-phase, and common wire) pulled out from the coil 42 of the stator 40 . Preferably: only one lead wire 43 passes through one through hole 35 .

The lower opening portion of the base portion 34 of the through hole 35 includes a concave portion 36 having a larger diameter than the through hole 35 . Specifically, the recesses 36 of the W-phase and V-phase through-holes 35 include long hole shapes that connect the through-holes 35 to each other. In addition, the concave portion 36 of the through-hole 35 of the U-phase and common line includes a long hole shape connecting the through-holes 35 to each other. Between the circumferential direction of each through-hole 35, the wall part 58 which partitions each recessed part 36 is arrange|positioned.

The base portion 34 includes a bottom portion 34 a having a through hole 35 , and a side wall portion 34 b extending upward from the outer peripheral portion of the bottom portion 34 a. The bottom portion 34a includes a communication groove 38 continuous with the recessed portion 36 and the side wall portion 34b. More specifically, the bottom portion 34a includes a communication groove 38 through which the lead-out wires 43 drawn from the through-holes 35 of the W-phase and V-phase pass, and a communication groove 38 through which the lead-out wires 43 pulled out from the through-holes 35 of the U-phase and common lines pass. Passed communication groove 38. The circumferential width of the communication groove 38 is wider than that of the communication groove in the modification example of the above-mentioned embodiment.

The circuit substrate 60 is arranged at the lower surface of the base plate 31 on the radially outer side than the base portion 34 . The circuit board 60 is attached to the lower surface of the bottom plate 31 via an adhesive layer 61 .

Each lead wire 43 extends toward the circuit board 60 through the through-hole 35 and the communication groove 38 of the base 34 . The lead wires 43 are soldered to the pad portions 65 of the circuit board 60 to be electrically connected to the circuit board 60 .

The through hole 35 is sealed by a sealing material 55 located in the recess 36 and the communication groove 38 . The sealing material 55 contains a thermosetting adhesive. In the through hole 35 , the concave portion 36 and the communicating groove 38 , the sealing material 55 is positioned so as not to move the lead wire 43 .

Since two communication grooves 38 having a wide width are arranged for four through-holes 35 , sufficient wiring space for lead wires 43 can be obtained.

FIG. 9 is a plan view showing the configuration of a spindle motor according to Embodiment 3. FIG. The basic structure is almost the same as that of Embodiment 1, and the same reference numerals are assigned to the same parts as in Embodiment 1, and only different parts will be described.

As shown in FIG. 9 , the lower surface of the bottom plate 31 includes a thick base portion 34 expanding radially around the central axis J1 . The base portion 34 preferably includes a bottom portion 34a and a side wall portion 34b extending upward from the outer peripheral portion of the bottom portion 34a. Preferably the bottom 34a includes four recesses 57 . Preferably, one through hole 35 is assigned to each recess 57 .

The recessed portions 57 communicate with each other through the housing portion 37 arranged radially outward from the through hole 35 . The storage portion 37 extends in the circumferential direction. Between the circumferential direction of each through-hole 35, the wall part 58 which partitions each recessed part 57 is arrange|positioned.

The circuit board 60 extends in the circumferential direction inside the housing portion 37 . The groove portion 66 is arranged on the inner side in the radial direction of the circuit board 60 corresponding to the wall portion 58 .

In Embodiment 3, in addition to the through hole 35 , the pad portion 65 of the circuit board 60 is arranged in the concave portion 57 . The pad portion 65 includes a pad hole 65 a overlapping with the through hole 35 in the axial direction. The diameter of the pad hole 65 a is preferably smaller than the diameter of the through hole 35 . Preferably: only one lead wire 43 passes through one through hole 35 . The lead wire 43 reaches the lower surface of the base 34 through the pad hole 65 a. The lead wires 43 reaching the lower surface are soldered to the pad portions 65 of the circuit board 60 to be electrically connected to the circuit board 60 . The pad hole 65 a is closed with solder 48 .

In the structure in which the plurality of recesses 57 are arranged on the lower surface of the base 34 , the plurality of recesses 57 are arranged on the lower surface of the base 34 by planing the portion on the lower surface of the base 34 corresponding to the lead wire 43 . Therefore, compared with the conventional structure, the area of the planed base 34 can be reduced, and the rigidity of the base 34 can be improved. In addition, it is preferable that the recessed portion 57 has a minimum size that can smoothly pull the lead wire 43 out of the through hole 35 , and this structure can further reduce the area of the planed base portion 34 . Moreover, the rigidity of the base part 34 can be improved by the wall part 58 arrange|positioned between each through-hole 35. FIG.

In addition, sealing the through hole 35 with the pad portion 65 of the circuit board 60 and sealing the pad hole 65 a with the solder 48 can improve airtightness. Therefore, it is possible to prevent air and the like from entering and exiting the housing 13 of the hard disk drive device 1 through the through hole 35 . In addition, if the sealing material is located in the recess 57 and the solder 48 is covered with the sealing material, further airtightness can be obtained.

As the sealing material, as in Embodiment 1, it is preferable to use a thermosetting adhesive. However, for the sealing material, various adhesives such as ultraviolet curing adhesives may be used instead of thermosetting adhesives. In addition, as long as airtightness can be obtained, a sealing material other than an adhesive may be used. For example, a sealing material other than an adhesive that is liquid or gel in an applied state may be used.

FIG. 10 is a plan view showing Modification 1 of Embodiment 3. FIG. As shown in FIG. 10 , the base portion 34 includes a bottom portion 34 a and a side wall portion 34 b extending upward from the outer peripheral portion of the bottom portion 34 a. The bottom 34a includes two recesses 57 . Preferably, two through-holes 35 are arranged for each concave portion 57 .

The recessed portions 57 communicate with each other through the housing portion 37 arranged radially outward from the through hole 35 . Between the through-holes 35 of the respective recesses 57 , wall portions 58 for partitioning the respective recesses 57 are arranged. In addition, the through-holes 35 arranged in each recessed part 57 are not limited to two per recessed part, as long as one or more are included.

In the concave portion 57 , in addition to the through hole 35 , the pad portion 65 of the circuit board 60 is arranged. The groove portion 66 is arranged on the inner side in the radial direction of the circuit board 60 corresponding to the wall portion 58 .

FIG. 11 is a plan view showing Modification 2 of Embodiment 3. FIG. As shown in FIG. 11 , the base portion 34 includes a bottom portion 34 a and a side wall portion 34 b extending upward from the outer peripheral portion of the bottom portion 34 a. Preferably the bottom 34a includes three recesses 57 . Preferably, one through-hole 35 is arranged in each of the recesses 57 located on both sides in the circumferential direction of the base 34 . Preferably, two through-holes are disposed in the recess 57 located at the center in the circumferential direction.

The concave portions 57 communicate with each other through the housing portion 37 disposed radially inward of the through hole 35 . Between the through-holes 35 of the respective recesses 57 , wall portions 58 for partitioning the respective recesses 57 are arranged. In addition, the wall part 58 is not limited to the illustrated arrangement|positioning, You may change the number and arrangement|positioning.

In the concave portion 57 , in addition to the through hole 35 , the pad portion 65 of the circuit board 60 is arranged. The groove portion 66 is arranged on the radially outer side of the circuit board 60 corresponding to the wall portion 58 .

Although the embodiments and modifications of the spindle motor have been described above, the present invention is not limited to the embodiments and modifications, and various modifications and modifications can be made without departing from the scope of the invention.

In the embodiment, a structure including four through holes 35 corresponding to four lead lines 43 (W phase, V phase, U phase, common line) was described, but it is only necessary to include one or more through holes 35 .

For example, four lead wires may be pulled out from one through hole, or two lead wires may be pulled out from two through holes respectively. In addition, among the two through-holes, one lead-out wire may be pulled out from one through-hole and a plurality of lead-out wires may be pulled out from the other through-hole. For example, the common line may be pulled out from one through hole, and the three lead lines of U-phase, V-phase, and W-phase may be pulled out from the other through-hole.

In addition, the number of lead wires 43 is not limited to four, and may be, for example, three lead wires of U-phase, V-phase and W-phase.

In addition, in the embodiment, it is preferable that the distance from the through hole 35 of the W phase and the common line to each land portion 65 of the circuit board 60 is longer than the distance from the through hole 35 of the V phase and U phase to each land portion 65. . Therefore, the protruding portion 60 a of the circuit board 60 is disposed and insulated between the W-phase and the common lead wire 43 with the film-removed portion 44 and the bottom plate 31 . However, if the distances from the through-holes 35 to the pads 65 are substantially equal, the protrusions 60 a may not be arranged from the viewpoint of insulation between the film-removed portion and the bottom plate.

In addition, the structure in which the insulating bush 45 is arranged in the through hole 35 so that the lead-out wire 43 does not come into electrical contact with the base plate 31 has been described. However, for example, an insulating film may be disposed between the stator 40 and the bottom plate 31 .

In addition, although the form in which the bottom plate 31 and the case 13 are comprised by a single member was demonstrated, it is also possible to comprise the bottom plate 31 and the case 13 with different members.

In addition, although the case where the illustrated embodiment is applied to the outer rotor type spindle motor 10 has been described, the illustrated embodiment can also be applied to an inner rotor type motor.

In addition, the bearing mechanism 25 of the motor 10 is not limited to a bearing utilizing fluid dynamic pressure, and other sliding bearings or bearings of other structures may be used.

Furthermore, as the circuit board, various circuit boards may be used, not limited to flexible circuit boards, and hard boards such as connectors may be used, for example.

As described above, the present invention is very useful and industrially applicable because it can obtain a highly practical effect of ensuring the rigidity of the base in the spindle motor and the disk drive device including the spindle motor. very high.

Only preferred embodiments have been chosen to illustrate the invention. However, various modifications and changes may be made by those skilled in the art based on the above disclosure without departing from the scope of the present invention defined by the appended claims. Also, the above description of the preferred embodiments of the present invention is for illustration only and not for limitation of the invention as defined by the appended claims and their equivalents.

Claims (7)

1. A spindle motor, the spindle motor comprising: a base comprising a plurality of through holes and radially expanding around the central axis; a rotor hub positioned on the upper side of the base and rotating about the central axis; a stator located on the upper side of the base and including coils having lead wires; and a circuit substrate on the lower surface of the base, The base has on its lower surface at least one recess between adjacent ones of the plurality of through holes separated by a wall, In each of the recesses, at least one of the through holes is arranged, The lead-out line reaches the lower surface of the base through the through hole, and is electrically connected to the pad portion of the circuit board. 2. The spindle motor according to claim 1, wherein, The pad part is arranged in the concave part. 3. The spindle motor according to claim 2, wherein, The pad portion includes a pad hole axially overlapping the through hole, the lead-out wire passes through the pad hole to reach the lower surface of the pad portion, and is soldered on the pad portion, Use solder to close the pad holes. 4. The spindle motor according to claim 3, wherein, The solder is covered by a sealing material. 5. The spindle motor according to claim 1, wherein, Only one lead-out wire passes through each of the through holes. 6. The spindle motor according to claim 1, wherein, One of the through-holes is arranged in each of the recesses. 7. A disc drive comprising a recording disc, the disc drive comprising: the spindle motor of claim 1 that rotates the recording disk; an access unit that reads and/or writes information to the recording disc; and The case is composed of a first case part including the base part and a second case part, and accommodates the spindle motor and the access part.