JP4141598B2 - Disk drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk drive device that rotationally drives a recording disk such as a hard disk by a spindle motor.
[0002]
[Prior art]
In a disk drive device that rotates a recording disk such as a hard disk and reads / writes information from / to this recording disk, an apparatus circuit board is arranged on the back side of the base of the apparatus for power supply and control to the spindle motor for rotating the recording disk. Established.
[0003]
In addition, in order to reduce the thickness of the disk drive device, the bottom of the motor part is protruded on the back surface of the base, and a circuit hole on the back surface of the base is provided with a through hole in which the protruded bottom part is loosely fitted. It does not interfere in the height direction.
[0004]
In this case, electrical connection between the spindle motor and the device circuit board is performed using a flexible circuit board. That is, the base of the flexible circuit board is attached to the back of the motor bottom, the middle part is bent along the convex shape of the motor bottom, and the tip is attached to a height substantially equal to the back of the base. The coil wire of the stator inside the motor is led out to the back side of the base and is electrically connected to the base of the flexible circuit board, and the contact on the device circuit board comes into contact with the tip of the flexible circuit board. A motor control circuit on the substrate is connected to the coil wire of the stator.
[0005]
[Problems to be solved by the invention]
In the above-described prior art, the flexible circuit board that performs electrical connection between the motor and the apparatus circuit board is used in a folded state after the base portion and the distal end portion are adhered. If the adhesive strength of the tip of the circuit board is weak or weakens due to aging, etc., the tip of the flexible circuit board will peel off from the fixing member and jump up, making the electrical connection with the device circuit board unstable. There is a problem that does not function normally.
[0006]
The present invention has been made in consideration of the above-described problems of the prior art, and its purpose is to reliably prevent the flexible circuit board from jumping up.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the disk drive device according to the present invention, a rotor having a rotor magnet supported rotatably via a bearing with respect to the fixed member, and the fixed member facing the rotor magnet. A spindle motor comprising: a stator integrally supported; and a flexible circuit board for connecting a coil wire end of the stator to a motor circuit of an apparatus circuit board disposed on the back surface side of the fixing member. A disk drive device for holding a recording disk on the rotor of the spindle motor and rotating the recording disk;
On the lower surface of the fixing member, a coil wire connecting portion that is positioned corresponding to the stator and has a guide hole through which a coil wire end portion of the stator is led out is adjacent to the coil wire connecting portion. And an external connection portion that is lowered with a step when viewed from the lower surface of the fixing member, and the flexible circuit board has a base portion attached to the coil wire connection portion and the land portion of the base portion. The end portion of the coil wire led out from the guide hole is connected, and the terminal portion of the distal end portion that is electrically connected to the land portion by being attached to the external connection portion is connected to an external circuit. In addition, the external connection portion of the fixing member is formed with a protrusion that engages with a leading edge of the leading end portion of the flexible circuit board to prevent its jumping. To do.
[0008]
In the above, the fixing member refers to the base and the bracket when the spindle motor bracket as a separate part is attached to the base of the disk drive device, and the coil wire connecting portion and the external connecting portion are formed on the lower surface of the bracket. When the spindle motor is directly integrated with the base, the base corresponds to the fixing member. The flexible circuit board in which the base portion is bonded to the coil wire connection portion of the fixing member is bent at the intermediate portion, and the tip end portion is bonded to the external connection portion of the fixing member.
[0009]
The protrusion formed on the external connection portion faces the tip portion of the flexible circuit board, and the tip edge thereof can be engaged with the protrusion. Even if the adhesive force of the front end portion of the flexible circuit board is weakened to be peeled off from the external connection portion, the front end portion of the flexible circuit board is prevented from jumping up by engaging with the protrusion.
[0010]
Further, in the spindle motor, the coil wire connection portion, the external connection portion, and the side surface portion connecting both the connection portions of the fixing member are continuously formed in a concave shape so as to accommodate the flexible circuit board. It is desirable that Thereby, a space for accommodating the flexible circuit board can be secured, and the flexible circuit board does not protrude from the fixing member.
[0011]
Further, in the spindle motor, a coil wire insertion hole is formed in the land portion of the base portion of the flexible circuit board so as to correspond to the guide hole, and the coil is guided to the outside through the guide hole and the insertion hole. The wire end can be soldered to the land. As a result, the guide hole is blocked by the solder, and therefore, the guide hole of the bracket and the insertion hole of the flexible circuit board are blocked, and there is a sealing effect that prevents outside air from entering the motor.
[0012]
The protrusion formed on the external connection portion of the fixing member of the spindle motor may partially correspond to the tip portion of the flexible circuit board. In this case, in addition to preventing the flexible circuit board from jumping up by providing a protrusion, when adhering the tip of the flexible circuit board to the external connection part, hold the tip part of the part that does not correspond to the protrusion to the surface of the external connection part. Therefore, the work can be facilitated and can be reliably bonded without creating a gap between them.
[0013]
A terminal portion at the tip of the flexible circuit board in the spindle motor may be exposed and a contact on a circuit board attached to the lower surface of the fixing member may be elastically contacted with the terminal portion. In addition, an inspection electrode portion that is electrically connected to the land portion and the terminal portion can be exposed at a position near the tip portion of the base portion of the flexible circuit board. As described above, by providing the inspection electrode part separately from the connection electrode part, it is possible to prevent the connection electrode part from being damaged in the inspection process.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described in detail with reference to FIGS.
1 is a cut-away side view showing a spindle motor according to an embodiment of the present invention, FIG. 2 is a bottom view showing a part of the spindle motor of FIG. 1, and FIG. 3 is a front view of the spindle motor of FIG. FIG.
[0015]
This embodiment is a case where the present invention is applied to a hard disk drive, in which a disk rotating spindle motor 10 is fixed to the apparatus base 2 so that a rotor portion on which the disk is mounted is exposed to the disk chamber 4, and motor control is performed on the back surface of the base 2. An apparatus circuit board 6 including a circuit is disposed.
[0016]
The spindle motor 10 includes a thin dish-shaped bracket 12, a fixed shaft 14 planted in the center of the bracket 12, and a rotor hub 18 rotatably supported on the shaft 14 via a pair of bearings 16. The stator 20 is fixed to the bracket 12 so as to correspond to the base portion of the shaft 14, and the bracket 12 and the shaft 14 constitute a fixing member.
[0017]
The bracket 12 is formed by raising an annular bottom wall portion 12a, a support cylinder portion 12b formed by raising an inner peripheral portion of the bottom wall portion 12a upward, and an outer peripheral portion of the bottom wall portion 12a rising upward. Side wall portion 12c, an annular step portion 12d formed by bulging the upper end portion of the side wall portion 12c radially outward, and a portion extending radially outward from the upper end portion of the annular step portion 12d. The base portion of the shaft 14 is fixed to the inside of the support cylinder portion 12b by press-fitting, bonding, etc., and the stator 20 is externally fixed to the outer periphery of the support cylinder portion 12b. .
[0018]
The lower surface of the bracket 12, that is, the lower surface of the bottom wall portion 12a, the lower surface of the annular step portion 12d, and the lower surface of the flange portion 12e are gradually lowered from the bottom, and the bracket 12 is lowered to the base 2 and the flange portion 12e. An annular step 12 d is fitted into the motor opening 2 a of the base 2 and fixed so that the lower surface of the base 2 abuts the upper surface of the base 2. As a result, the bracket 12 has a part of the lower side of the annular stepped portion 12d, the side wall portion 12c, and the bottom wall portion 12a protruding downward from the base 2.
[0019]
The rotor hub 18 includes a cylindrical bush 18a made of, for example, stainless steel, on which the outer rings of both the bearings 16 are fitted and fixed, and a hub 18b made of, for example, aluminum or an aluminum alloy, which is fitted and fixed to the outer peripheral surface of the cylindrical bush 18a. The cylindrical yoke 18c fitted on the lower inner periphery of the hub 18b and the cylindrical rotor magnet 18d mounted on the inner peripheral surface of the yoke 18c are opposed to the stator 20 with a slight gap. is doing. The hub 18b is provided with a disk mounting portion 18b1 projecting radially outward at the lower end thereof, and one or more recording disks are mounted on the upper surface of the hub 18b and are clamped by a clamp screwed to the hub 18b. And is held by the hub 18b. A magnetic fluid seal 22 for preventing dust and the like from the bearing 16 from flowing out to the disk chamber 4 is provided on the inner peripheral portion of the rotor 18 on the upper surface of the upper bearing 16, and the shaft 14 is provided on the lower surface of the lower bearing 16. Labyrinth caps 24 that form minute gaps between them are respectively disposed.
[0020]
As is well known, the stator 20 includes a stator core 20a formed by laminating a plurality of stator laminations and a plurality of (for example, three-phase) coil wires 20b wound around the stator core 20a. The common end portion is led out of the motor through a plurality of (four in this example) guide holes 12a1 formed through the bottom wall portion 12a of the bracket 12. Insulating paper 26 is attached to the upper surface of the bottom wall portion 12a in order to ensure insulation between the coil wire 20b of the stator 20 and the bracket 12, and the insulating paper 26 corresponds to each guide hole 12a1. The cylindrical portion 26a formed in this manner avoids contact between the end 20b1 of the coil wire 20b and the peripheral edge of the guide hole 12a1, thereby ensuring insulation.
[0021]
A flexible circuit board (hereinafter referred to as FPC) 28 to which the end 20b1 of the coil wire 20b led out from the bracket 12 is electrically connected is attached to the lower surface of the bracket 12. Here, although the lower surface of the bracket 12 is formed with a step as described above, an FPC guide portion 12f extending from the bottom wall portion 12a to the annular step portion 12d through the side wall portion 12c is continuously formed in a part thereof. It is formed in a concave shape. A portion corresponding to the bottom wall portion 12a of the FPC guide portion 12f is a coil wire connection portion 12f1, the guide hole 12a1 is located in this portion, and a portion corresponding to the annular step portion 12d of the FPC guide portion 12f is the external connection portion 12f2. It becomes. The depth of the recessed shape of the FPC guide portion 12f is set larger than the thickness of the FPC 28, and the FPC 28 does not protrude from the guide portion 12f.
[0022]
The FPC 28 has a base portion 28a attached to the coil wire connection portion 12f1 of the FPC guide portion 12f, an intermediate portion 28b disposed at a position corresponding to the side wall portion 12c of the FPC guide portion 12f, and a tip portion 28c of the FPC guide portion 12f. It is affixed to the external connection part 12f2. The base portion 28a of the FPC 28 is formed to be relatively large in order to solder-connect the coil wire ends and the like, and as is apparent from FIG. 2, four land portions 28a1 are provided corresponding to the respective guide holes 12a1. In addition, a coil wire insertion hole 28a2 communicating with the guide hole 12a1 is formed in the center of each land portion 28a1, and the end 20b1 and the common end of the coil wire 20b inserted through each guide hole 12a1 are inserted through the coil wire. It is led out through the hole 28a2 and soldered to the land 28a1. As understood from FIG. 1, the solder portion 30 provided in the land portion 28a1 for connecting the end portion 20b1 and the common end portion of the coil wire 20b closes the coil wire insertion hole 28a2. External air can be prevented from entering the motor through the insertion hole 28a2 and the guide hole 12a1, or vice versa.
[0023]
The intermediate portion 28b and the distal end portion 28c of the FPC 28 are formed to have a width necessary for arranging four copper foil patterns in parallel and about half the width of the base portion 28a, and the distal end portion 28c has a land portion 28a1. Four terminal portions 28c1 that are electrically connected to each other are exposed. The device circuit board 6 is provided with a spring contact 6a that elastically contacts each terminal portion 28c1 at a position corresponding to the tip portion 28c of the FPC 28. Each contact 6a is connected to a motor control circuit provided on the device circuit board 6, and therefore each coil wire 20b of the stator 20 is connected to the motor control circuit via the FPC 28 and the contact 6a.
[0024]
On the base portion 28a of the FPC 28, an inspection electrode portion 28a3 that is electrically connected to each land portion 28a1 and each terminal portion 28c1 is exposed near the tip portion. This electrode portion 28a3 is used, for example, when inspecting the motor alone or rotating the rotor for testing, and since it is not necessary to use the terminal portion 28c1, the terminal portion 28c1 is damaged before the spindle motor 4 is mounted on the apparatus. There are no defects such as sticking.
[0025]
The external connection portion 12f2 of the bracket 12 is formed with a protrusion 32 at the end edge thereof that opposes the front end portion 28c of the FPC 28, and a part of the end edge of the front end portion 28c can be engaged with the protrusion 32. The protrusion 32 is formed by projecting at least a dimension longer than the thickness of the FPC 28 from the bottom surface of the external connection portion 12f2, and the dimension in the width direction is set to about ３ of the width of the distal end portion 28c. Here, the protrusion 32 is not formed in accordance with the width of the tip end portion 28c because the tip end portion 28c of the FPC 28 is guided to the bottom surface position of the external connection portion 12f2 by using a tool such as tweezers. This is to form a relief from 12f2.
[0026]
Since the FPC 28 is usually formed in a flat state and itself has elasticity, when the FPC 28 is used in a folded state, it always has a restoring force. The FPC 28 is bent with its base 28a and tip 28c attached to the coil wire connecting portion 12f1 and the external connecting portion 12f2, respectively, but the coil wire end 12a1 and common end are soldered. And the adhesive strength of the base part 28a is larger than the front-end | tip part 28c from the point with a large area. Accordingly, a decrease in the adhesion force of the FPC 28 to the bracket 12 and deterioration of the adhesion performance due to aging are likely to occur at the tip portion 28c, and the tip portion 28c rises or jumps up from the external connection portion 12f2, and the contact state with the contact 6a is not good. It tends to be stable.
[0027]
In the above-described embodiment, since the protrusion 32 is provided on the external connection portion 12f2 of the bracket 12 so as to face the front end portion 28c of the FPC 28, the sticking force of the front end portion 28c is temporarily reduced and the protrusion from the external connection portion 12f2 is lifted. Even if it is about to occur, the tip edge of the tip portion 28c can be prevented from coming into contact with and engaging with the protrusion 32 to cause further displacement, so that the tip portion 28c can be reliably prevented from jumping up, As a result, it is possible to maintain the stabilization of the contact state with the contact 6a.
[0028]
In the above-described embodiment, the disk drive device in which the bracket 12 of the spindle motor 4 is attached to the device base 2 has been described. However, the present invention is also applicable to a base-integrated spindle motor in which the spindle motor is directly incorporated into the base. The same can be applied. In this case, the coil wire connecting portion and the external connecting portion may be formed with a step on the portion corresponding to the base motor, that is, the fixing member of the spindle motor.
[0029]
Further, the protrusion formed on the external connection portion may be at least partially engaged with the front end portion of the FPC, and may be partially or entirely opposed to the front end portion of the FPC.
[0030]
【The invention's effect】
Since the disk drive apparatus of the present invention is configured as described above, the following effects can be obtained.
In the disk drive device according to claim 1, the base portion and the distal end portion of the flexible circuit board are respectively attached to the coil wire connection portion and the external connection portion formed with a step in the fixing member of the spindle motor. Since the protrusion that engages the tip edge of the tip of the flexible circuit board is formed on the external connection portion, the tip edge engages with the protrusion even when the sticking force of the tip is reduced. It is possible to reliably prevent the portion from jumping up, to stably maintain the connection state between the terminal portion of the tip portion and the device circuit board, and to improve the reliability.
[0031]
In the disk drive device according to claim 2, since the coil wire connection portion and the external connection portion of the fixing member and the side surface portion connecting both of them are continuously formed in a concave shape, the flexible circuit board is fixed. Without protruding from the member, the flexible circuit board can be prevented from interfering with other components or being damaged by some factor.
[0032]
Furthermore, in the disk drive device according to claim 3, a coil wire insertion hole corresponding to the guide hole of the bracket is formed in the land portion of the base portion of the flexible circuit board, and the coil is connected by solder for connecting the coil wire. Since the wire insertion hole is closed, the guide hole can be indirectly closed, and the flow of air inside and outside the motor through the guide hole and the coil wire insertion hole can be reliably prevented.
[0033]
5. The disk drive device according to claim 4, wherein the protrusion formed on the external connection portion of the fixing member is partially associated with the front end portion of the flexible circuit board, and the front end portion is guided to the external connection portion. Becomes easier and workability is improved.
[0034]
In the disk drive device according to claim 5, in order to expose and form the terminal portion of the tip portion of the flexible circuit board and to elastically contact the contact on the device circuit board, In addition to preventing jumping and maintaining stable connection, the connection structure between the spindle motor and the device circuit board is simpler and better handled.
[0035]
In the disk drive device according to claim 6, various inspections can be performed by a single motor without using the tip of the flexible circuit board by exposing the inspection electrode part to the base part of the flexible circuit board. be able to.
[Brief description of the drawings]
FIG. 1 is a cutaway side view showing an embodiment of a recording disk drive device of the present invention.
FIG. 2 is a bottom view of a part of the spindle motor of FIG.
FIG. 3 is a front view of FIG. 1;
[Brief description of symbols]
2 Base 6 Device circuit board 6a Contact 10 Spindle motor 12 Bracket 12a1 Guide hole 12f1 Coil wire connection portion 12f2 External connection portion 16 Bearing 18 Rotor 18d Rotor magnet 20 Stator 20b Coil wire 20b1 End portion 28 Flexible circuit board (FPC)
28a Base portion 28a1 Land portion 28a2 Coil wire insertion hole 28a3 Inspection electrode portion 28c Tip portion 28c1 Terminal portion 30 Solder 32 Protrusion

Claims (6)

A rotor having a rotor magnet that is rotatably supported by a fixed member via a bearing, a stator that is integrally supported by the fixed member so as to face the rotor magnet, and a coil wire end portion of the stator A spindle motor having a flexible circuit board for connecting to a motor circuit of an apparatus circuit board disposed on the back surface side of the fixing member, and holding a recording disk on the rotor of the spindle motor and rotating it In the disk drive device to drive,
On the lower surface of the fixing member, a coil wire connecting portion that is positioned corresponding to the stator and has a guide hole through which a coil wire end portion of the stator is led out is adjacent to the coil wire connecting portion. A lower external connection portion formed with a step when viewed from the lower surface of the fixing member,
The flexible circuit board has a base portion attached to the coil wire connection portion, the end portion of the coil wire led out from the guide hole is connected to the land portion of the base portion, and a distal end portion attached to the external connection portion. The terminal portion of the tip portion that is attached and is electrically connected to the land portion is formed to be connected to an external circuit,
In addition, the external drive portion of the fixing member is formed with a protrusion that engages with the leading edge of the leading end portion of the flexible circuit board to prevent the jumping thereof. 2. The coil wire connection portion, the external connection portion, and a side surface portion connecting the both connection portions of the fixing member are continuously formed in a concave shape so as to accommodate the flexible circuit board. Disk drive device. The land portion of the base portion of the flexible circuit board is provided with a coil wire insertion hole corresponding to the guide hole, and the end portion of the coil wire led out from the guide hole and the insertion hole is soldered to the land portion. The disk drive device according to claim 1, wherein the guide hole is closed. The disk drive device according to claim 1, wherein the protrusion formed on the external connection portion of the fixing member partially corresponds to a tip portion of the flexible circuit board. The disk drive device according to claim 1, wherein a terminal portion of the tip portion of the flexible circuit board is exposed and a contact on the device circuit board elastically contacts the terminal portion. 2. The disk drive device according to claim 1, wherein an inspection electrode portion that is electrically connected to the land portion and the terminal portion is exposed at a position near the tip portion of the base portion of the flexible circuit board.

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