JP2004247019A - Disk unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a magnetic disk device small in size, light in weight and low in cost by improving connection technology between VCM siries wirings and an FPC. <P>SOLUTION: This disk device is provided with a disk-like medium recording or reproducing information, an actuator on which a head performing recording or reproducing of information is mounted, a VCM driving the actuator, a coil holder 100 holding a coil 103 of the VCM, a FPC 104 transmitting a signal for performing delivery and receipt for a head and a signal for the VCM, a latch groove formed at a side plane of the coil holder 100, a lead line 107 end part and a ground line 108 end part of the coil arranged at the latch groove, and a connecting end part 202 of the FPC connecting a lead line end part and a ground tip part by being inserted into the latch groove. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a thin magnetic disk drive using a small-diameter magnetic disk, and more particularly to a technique for connecting VCM wiring to an FPC.
[0002]
[Prior art]
A magnetic disk device that uses a smaller-diameter magnetic recording medium that is smaller and thinner than a 2.5-type or 3.5-type magnetic disk device currently used in personal computers and the like is described in, for example, Patent Document 1. There is such a device.
[0003]
For example, a portable small-sized magnetic disk drive is thinner than a 2.5-type magnetic disk drive. Specifically, the device thickness of the 2.5-type magnetic disk device is 9.5 mm, whereas the device thickness of the portable small-sized magnetic disk device is as thin as about 5 mm.
[0004]
FIGS. 4 and 5 show a configuration of connecting a VCM system wiring (coil lead wire and ground wire) and an FPC in a general magnetic disk device. Looking at these enlarged views, the FPC ground wiring connection portion 303, which is an extension of the FPC 301, is mechanically fixed to the coil holder 300 by screws 305. The screw 305 has conductivity. The screw 305 sandwiches the ground wiring connection portion 303 of the FPC 301 between the coil holder 300. As a result, electrical connection from the coil holder 300 to the FPC ground wiring connection portion 303 and the FPC 301 through the screw 305 is performed. The reason for connecting the coil holder 300 to the ground via the screw 305 and the FPC 301 is to ground the magnetic head (earth). That is, by setting the magnetic head and the magnetic head grounded through the spindle motor to the same potential, the magnetic head is prevented from being damaged by static electricity generated between the magnetic head and the magnetic disk.
[0005]
A lead wire from the coil 302 is soldered on an upper surface of the coil holder at an FPC connection portion 304 which is an extension of the FPC 301. Even in a structure in which the coil holder 300 is molded from a resin material and the coil 302 is molded in the coil holder, the lead wire from the coil 302 is soldered to the FPC on the upper surface of the coil holder 300.
[0006]
[Patent Document 1]
JP-A-09-180426
[Problems to be solved by the invention]
When the FPC is fixed to the coil holder with a screw and ground connection is made, a thickness corresponding to the screw head is required, and it is difficult to further reduce the size and thickness of the magnetic disk device so as to be suitable for a portable type.
[0008]
Further, as the device becomes thinner, it becomes more difficult to secure a sufficient space between the coil holder and the yoke 407 of the VCM provided to face the coil holder. Therefore, it is more difficult to provide a screw on the coil holder from the viewpoint of securing space. Further, with the downsizing of the magnetic disk device, the dimensions of the coil holder itself become smaller, and it becomes difficult to secure a screw hole size corresponding to the FPC fixing screw size on the coil holder. In addition, it becomes difficult to secure a space for the coil lead wire to be soldered on the upper surface of the coil holder.
[0009]
In addition, if the screws are simultaneously made smaller and thinner as the device becomes smaller and thinner, the thread pitch must be made finer and the screw heights shall be made shallower in the screw processing. For this reason, it is not easy to machine the screw itself and the thread groove in the coil holder. Further, as the screw becomes smaller, the screw head must also be made smaller. In this case, the assembling workability is deteriorated, and the cost is also adversely affected.
[0010]
In other words, as the size and thickness of the magnetic disk drive are reduced, the screws must be reduced in size and thickness in a similar manner. However, when a certain limit is exceeded, the size reduction and thinning of the screw, which are substantially similar in shape, reach the limit in terms of strength and structure, and cannot be put to practical use. The magnetic disk drive has a structure in which a VCM yoke covers an upper surface of a coil holder on which a screw is installed. Therefore, with the downsizing and thinning of the magnetic disk device, a situation arises in which the yoke has to be cut only at the screw installation location in order to install the screw.
[0011]
Instead of fixing the coil holder and the FPC ground wiring connection portion with screws, there is a method in which a pin is pressed into the coil holder and the pin and the FPC connection portion are connected by soldering. Since the press-fit pin is smaller than the screw, it seems suitable for miniaturization. However, when this method is adopted, a process that is only one screw tightening process requires two processes of a pin press-fitting process and a solder connection process, and the assembling workability is deteriorated.
[0012]
Therefore, a magnetic disk drive that can reduce the size, thickness, and cost of a magnetic disk drive by solving the above-described problems and improving the technology for connecting the VCM wiring and the FPC is provided. Is required.
[0013]
[Means for Solving the Problems]
In order to solve the above problems, the following configuration is mainly used.
[0014]
A disk-shaped medium for recording information, an actuator equipped with a head for recording and / or reproducing information, a voice coil motor (VCM) for driving the actuator, a coil holder for holding a coil of the VCM, and a head A flexible printed circuit (FPC) for transmitting a signal to be transmitted / received and a signal to the VCM, and a connecting portion for connecting a lead wire end of the coil and an end of the FPC within a thickness dimension of the coil holder. Disk device.
[0015]
Alternatively, a cut groove formed on the side surface of the coil holder, a lead wire end of the coil disposed in the cut groove, and an end of the FPC connected to the lead wire end by being inserted into the cut groove. Disk device.
[0016]
Alternatively, a recessed portion formed in the coil holder, a connection board provided in the recessed portion and connected to a lead wire end of the coil, and a lead wire end on the connection board by being inserted into the recessed portion. It is assumed that the disk device has an end portion of the FPC to be connected.
[0017]
With such a configuration, the thickness of the magnetic disk device can be reduced (for example, approximately 5 mm or less). In addition, the ground connection and the connection with the coil lead wire can be realized without requiring special components for connecting to the FPC, and the contact at the FPC connection point can be surely performed.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
A magnetic disk drive according to an example of the present embodiment will be described below in detail with reference to FIGS. 1, 2, 3, and 6. FIG. 1 is a perspective view of the overall structure of the actuator of the magnetic disk drive according to the present embodiment. FIG. 2 is a diagram showing a detailed structure of a connection mode between a VCM (voice coil motor) system wiring (for example, a coil lead wire and a ground wire) and an FPC (flexible printed circuit) according to the present embodiment. FIG. 3 is a diagram showing a cross-sectional structure taken along line AA ′ of FIG. FIG. 6 is a perspective view showing the overall configuration of the magnetic disk drive.
[0019]
FIG. 6 is an example of a perspective view of a 2.5-type magnetic disk device mounted on a notebook personal computer. The inside of the magnetic disk drive is hermetically sealed by a housing 406 and a cover (not shown). The spindle motor is fixed to the housing 406. The magnetic disk 400 is fixed to the spindle motor by a clamp 413 with a spacer interposed therebetween. The spindle motor and the magnetic disk 400 may be fixed by bonding.
[0020]
An actuator is provided over the housing 406. A magnetic head 411 for reading and writing information from and to the magnetic disk 400 is attached to the tip of the suspension 402. Further, the actuator equipped with the magnetic head has a degree of freedom in the radial direction of the magnetic disk 400 with the pivot 412 as a rotation fulcrum. Thereby, the magnetic head is driven to a predetermined position on the surface of the magnetic disk 400 by the VCM fixed to the housing 406. In the present specification, the magnetic head is not a magnetic head in a narrow sense showing only the electromagnetic conversion element portion, but includes an electromagnetic conversion element section and a slider section for stably floating the electromagnetic conversion element section on a magnetic disk. It is used in a broad sense. Further, the electromagnetic conversion element includes a recording unit and a reproducing unit, but only one of them may be used.
[0021]
The signal from the magnetic head 411 is amplified by the preamplifier IC 404 via the FPC 403. The pre-main amplifier IC 404 is connected to a PCB (printed circuit board: not shown in FIG. 6) via a connector (not shown in FIG. 6). Therefore, the signal amplified by the pre-main amplifier IC 404 is subjected to signal processing by electronic components mounted on the PCB, and sent to the outside of the magnetic disk device by an external connector (not shown in FIG. 6). Note that the FPC 403 of the present embodiment is fixed with its actuator-side end facing the yoke 407 in a direction opposite to the normal direction, as described below. Therefore, the end on the side of the preamplifier IC 404 is also connected to the position between the preamplifier IC 404 and the long side of the housing 406, not between the preamplifier IC 404 and the short side of the housing 406.
[0022]
An actuator as shown in FIG. 1 is provided in the housing 406 of the magnetic disk device according to the present embodiment. A part of this actuator is constituted by a suspension 101. At the tip of the suspension 101, a magnetic head 105 for reading / writing information from / on a magnetic disk 400 as a recording medium is mounted. The actuator can be rotated by the pivot 102 with a degree of freedom in the radial direction of the magnetic disk. Then, the VCM (voice coil motor) provided in the housing is rotated to position the magnetic head 105 at a predetermined position on the surface of the magnetic disk.
[0023]
That is, the actuator in the magnetic disk device includes the magnetic head 105, the suspension 101, the guide arm, and the coil holder 100. The VCM includes a coil, a magnet, and a yoke in the coil holder 100 (in a narrow sense, the VCM may refer to a magnet and a yoke fixed to a magnetic disk device). The VCM and the actuator are provided with a ground wire for setting the coil lead wire and the magnetic head 105 to a ground potential. The lead wire and the ground wire are connected to corresponding connection portions of the FPC 104, respectively.
[0024]
More specifically, the coil 103 is a part of a driving unit that positions the magnetic head 105 mounted on the tip of the actuator at an arbitrary position on the magnetic disk 400. Then, a lead wire from the coil 103 and a ground wire for making the magnetic head 105 and the magnetic disk have the same potential are connected to corresponding connection portions of the FPC 104, respectively.
[0025]
In the present embodiment, the coil holder 100 is molded of a resin material and is integrated with the coil 103. Then, as shown in FIG. 2, slits or cut grooves (hereinafter, collectively referred to as slits) are formed on the side surface of the coil holder 100. The FPC 104 or the FPC 104 reinforced by the reinforcing plate 106 is inserted into this slit, and the coil lead wire and the ground wire are electrically connected to the FPC. With such a configuration, the actuator for positioning the magnetic head 105, specifically, the coil holder 100, can perform an electrical connection function with the FPC 104 without requiring a special connector. Note that, for convenience, surfaces parallel to the recording surface of the magnetic disk 400 are referred to as upper and lower surfaces, and a surface perpendicular to the recording surface of the magnetic disk 400 is referred to as a side surface. A slit may be formed on the upper surface or the lower surface.
[0026]
FIG. 2 is an enlarged view of a portion where a coil lead wire and a ground wire, which are VCM wires, are connected to the FPC 104. As described above, the coil holder 100 in which the coil 103 is integrated is molded from a resin material. Further, the lead wire 107 from the coil 103 is soldered to the connection end 201 on the coil holder 100 side of the FPC connection board 200 integrally (for example, resin-molded) mounted on the coil holder 100. The FPC connection board 200 is positioned and fixed to the coil holder 100 such that the solder surface of the connection end 202 on the FPC side is in contact with the connection end 201 on the coil holder side. The FPC connection board 200 is also connected to a ground line 108 that is electrically connected to the magnetic head.
[0027]
FIG. 3 is a diagram showing a detailed structure of the FPC connection board 200. This is an example in which two coil lead wires 107 and one ground wire 108 are wired from the coil holder 100 side to the FPC connection board 200 to form a connection end 201.
[0028]
The FPC connection board 200 is fixed to the slit surface of the coil holder 100 so that it can be connected to the connection part on the FPC side. In the coil holder 100, both the coil 103 and the FPC connection board 200 are integrally formed of resin. The FPC connection board 200 is fixed such that the electrical connection end 202 protrudes inside the slit. Therefore, only by inserting the positioned FPC 104 into the slit, the connection between the lead wire of the coil 103, the connection end 201 on the ground line side, and the corresponding connection end 202 on the FPC side becomes possible.
[0029]
The connection portion of the FPC 104 is a single structure of the FPC 104 or a structure in which the FPC 104 is attached to the reinforcing plate 106. The connection portion of the FPC 104 is inserted and positioned in a slit from which the electrical connection portion of the FPC connection board 200 projects. Here, the reinforcing plate 106 is desirably formed of a thin metal or resin material from the viewpoint of ease of insertion and reinforcement of the FPC. As can be seen from FIG. 3, the FPC connection portion is within the thickness dimension of the coil holder 100. Therefore, the connection structure between the VCM wiring and the FPC 104 does not become an obstacle in reducing the size and thickness of the magnetic disk device as compared with the screw and solder connection structure of the general technique shown in FIG. .
[0030]
Further, in order to prevent the FPC 104 inserted into the slit from coming off, a hook portion is formed at the end of the reinforcing plate 106 or the FPC, and a locking portion for locking the hook portion in the slit (for example, a recess formed in the slit). ) Is formed. The hook portion and the locking portion constitute a stopper portion 203 that functions as a slip-off prevention mechanism. The stopper 203 enables the FPC 104 to maintain contact without coming off even when vibration or impact is applied to the magnetic disk device during operation. FIG. 2 illustrates a structure in which the stopper function works in the insertion direction of the FPC 104. Note that a similar stopper portion including a hook portion and a locking portion may be provided in the thickness direction of the coil holder 100. By providing such a stopper portion, a special dedicated part for preventing the FPC from coming off is not required, the structure is simple, the assembling workability is good, and the FPC connection corresponding to the miniaturization and the thinning becomes possible.
[0031]
A second embodiment of the connection mode between the VCM wiring (the lead wire 107 from the coil and the ground wire 108) and the FPC 104 will be described with reference to FIGS. 7, 8, and 9. FIG. In the configuration of the magnetic disk illustrated in FIG. 6 and the configuration of the actuator illustrated in FIG. 1, a slit or a cut groove (hereinafter, collectively referred to as a slit) is formed on a side surface of the coil holder 100.
[0032]
FIG. 7 is an enlarged view of a portion where a lead wire 107 from a coil, which is a VCM wiring before the FPC 104 is inserted, and a ground wire 108 are connected to the FPC 104. The coil holder 100 integrated with the coil 103 is molded from a resin material. Further, the lead wire 107 from the coil 103 is connected by soldering to a lead wire spring 600 integrally (for example, resin-molded) provided in the coil holder 100. Similarly, the ground wire 108 is connected to the ground wire spring 601 by soldering.
[0033]
FIG. 8 is a perspective view of a portion where the lead wire spring 600 and the ground wire spring 601 are connected to the FPC before the FPC 104 is inserted. Further, this is an example in which an FPC connection end is configured. The two lead wire springs 600 and one ground wire spring 601 are provided inside the slit of the coil holder 100 formed of resin. As is clear from FIG. 8, each of the springs 600 and 601 protrudes inside the slit, and is fixed at a position where the FPC 104 is always connected by crimping when the FPC 104 is inserted.
[0034]
FIG. 9 is an enlarged view of a portion where a lead wire 107 and a ground wire 108, which are VCM wirings, are connected to the FPC. The FPC 104 or the FPC 104 reinforced by the reinforcing plate 106 is inserted into the slit portion of the coil holder 100 shown in FIG. 7, and the lead wire 107 and the ground wire 108 are connected to the lead wire spring 600 and the ground wire spring 601. It is electrically connected to the FPC 104 at the solder surface 700 through the intermediary of the FPC 104. With such a configuration, the actuator for positioning the magnetic head, specifically, the coil holder 100 can perform an electrical connection function with the FPC 104 without requiring a special connector.
[0035]
In each embodiment, the coil 103 is insert-molded into the coil holder 100 and integrated. Therefore, the strength of the coil holder is increased as compared with a structure in which the coil is fixed to the metal coil holder with an adhesive. Further, by molding the coil 103 into the coil holder 100, the degree of freedom in design that the slit position can be set to an arbitrary position can be secured.
[0036]
In the above description, a magnetic disk device using a magnetic disk has been described. However, the present invention is not limited to this, and each embodiment is a technology applicable to a disk device using a magneto-optical disk or an optical disk. Further, in each of the above embodiments, the example in which the coil lead wire and the ground wire are illustrated as the configuration of the connection portion has been described. However, only the coil lead wire or a necessary wire other than the coil lead wire and the ground wire is used. May be included.
[0037]
【The invention's effect】
In this way, the screws used in the magnetic disk drive become unnecessary, and the number of components can be reduced. In addition, since it is not necessary to use expensive small and precise screws used in downsizing the magnetic disk drive, cost reduction can be realized.
[0038]
Further, in the case where the magnetic disk drive is downsized and thinned, it is difficult to secure a space for the thickness of the screw installed on the coil holder when using a screw. I had to cut some parts. However, according to each embodiment, since connection with the FPC contact can be performed within the thickness dimension range of the coil holder, there is no need to cut the VCM yoke. Therefore, it is possible to improve the performance of the magnetic disk drive by subtracting the VCM.
[Brief description of the drawings]
FIG. 1 is a perspective view of the overall structure of an actuator of a magnetic disk drive according to an embodiment.
FIG. 2 is a diagram showing a detailed structure of a connection mode between a VCM wiring (a coil lead wire and a ground wire) and an FPC according to the embodiment;
FIG. 3 is a diagram showing a cross-sectional structure taken along line AA ′ of FIG. 2;
FIG. 4 is a plan view of a coil holder showing a connection mode between VCM wiring (coil lead wire and ground wire) and an FPC in a general magnetic disk device.
FIG. 5 is an enlarged cross-sectional view taken along line BB ′ of FIG. 4;
FIG. 6 is a perspective view showing the overall configuration of a magnetic disk drive.
FIG. 7 is an enlarged plan view of an FPC connection location of a coil holder before FPC insertion according to a second embodiment.
FIG. 8 is an enlarged perspective view of an FPC connection location of the coil holder in FIG. 7;
FIG. 9 is a plan view of a coil holder showing a connection mode between a VCM wiring (coil lead wire and a ground wire) and an FPC in FIG. 7;
[Explanation of symbols]
100, 300: coil holder, 101, 402: suspension, 102, 412: pivot, 103, 302: coil, 104, 301, 403: FPC (flexible printed circuit), 105, 411: magnetic head, 106: reinforcing plate, 107: coil lead wire, 108: ground wire, 200: FPC connection board, 201: coil holder side connection, 202: FPC side connection, 203: FPC stopper, 303: FPC ground wiring connection, 304: FPC connection Reference numerals 305, screws, 400, magnetic disk, 404, electronic components, 406, housing, 407, VCM yoke, 413, clamp, 600, lead wire spring, 601, ground wire spring, 700, solder surface.

Claims (11)

Disc-shaped medium for recording information, a head for recording information on and / or reproducing information from the medium, an actuator equipped with the head, a voice coil motor for driving the actuator, and a voice coil A coil holder for holding a coil of the motor, a flexible printed circuit for transmitting a signal transmitted and received by the head, and a lead wire end of the coil and an end of the flexible printed circuit within a thickness dimension of the coil holder. A disk device comprising: a connection unit connected by a computer. The disk device according to claim 1,
The disk device, wherein the connection portion has a recess for locking a hook portion at an end of the flexible printed circuit. Disc-shaped medium for recording information, a head for recording information on and / or reproducing information from the medium, an actuator equipped with the head, a voice coil motor for driving the actuator, and a voice coil A coil holder for holding a coil of the motor, a flexible printed circuit for transmitting a signal transmitted to and received from the head, and a notch formed on the coil holder for connecting a lead wire end of the coil to an end of the flexible printed circuit; A disk device having a groove. The disk device according to claim 3,
The disk device wherein the cut groove is formed on a side surface of the coil holder. 5. The disk device according to claim 3, wherein
The disk device according to claim 1, wherein the notch has a recess for locking a hook provided at an end of the flexible printed circuit. Disc-shaped medium for recording information, a head for recording information on and / or reproducing information from the medium, an actuator equipped with the head, a voice coil motor for driving the actuator, and a voice coil A coil holder for holding a coil of the motor, a flexible printed circuit for transmitting a signal transmitted to and received from the head, a concave portion formed in the coil holder, and an end of the flexible printed circuit provided in the concave portion. A disk device comprising: a connection board connected to an end of a lead wire of the coil. 7. The disk device according to claim 1, wherein:
The disk device, wherein the coil holder is molded of a resin material, and the coil is insert-molded in the coil holder. The disk device according to any one of claims 1 to 7,
A disk device in which an end of the flexible printed circuit has a structure in which a reinforcing plate is attached. The disk device according to any one of claims 1 to 8,
A disk device wherein the reinforcing plate is made of a metal material or a resin material. 10. The disk device according to claim 1, wherein:
The disk device, wherein the connection portion includes an end of a ground line. The disk device according to claim 6,
A disk device comprising a detachment preventing mechanism in which the concave portion does not come off due to impact or vibration of an end of the flexible printed circuit.

Images