JP2001344945A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic disk device which can exactly detect the ambient temperature of a magnetic head and magnetic disk. SOLUTION: A spindle motor which supports and rotationally drives a magnetic disk and a head actuator which moves and positions the magnetic head at an arbitrary position with respect to the magnetic disk are placed on the bottom wall of a case. A main FPC 54 has one end connected to the head actuator and a base end 54b mounted via a metallic backing plate 65 on the bottom wall of the case. A head IC 60 for amplifying the signals from the magnetic head and a temperature sensor 64 which detects the ambient temperature of the magnetic head and the magnetic disk are packaged on the base end of the main FPC. A backing plate has an aperture 66 formed in a position facing the temperature sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly, to a magnetic disk drive having a temperature sensor for detecting a temperature inside the apparatus.

[0002]

2. Description of the Related Art Generally, a magnetic disk drive includes a magnetic disk disposed in a case, a spindle motor for supporting and rotating the magnetic disk, a carriage assembly for supporting a magnetic head, a voice coil motor for driving the carriage assembly, It is configured with a substrate unit and the like.

[0003] The carriage assembly includes a bearing mounted on a case, and a plurality of arms extending from the bearing. A magnetic head is mounted on each arm via a suspension. The board unit has a main flexible printed circuit board (hereinafter, referred to as a main FPC), and the tip of the main FPC extends to the vicinity of the bearing. Each magnetic head is connected to one end of a relay flexible printed circuit board (hereinafter, referred to as a relay FPC) provided on the arm, and the other end of the relay FPC is connected to the main FPC. Therefore, each magnetic head is electrically connected to the board unit via the relay FPC and the main FPC, and is controlled by the board unit.

A base plate of the main FPC has a backing plate made of stainless steel or the like attached to the back surface, and is fixed on the bottom wall of the case via the backing plate. At the base end of the main FPC, a connector, a head IC, and the like for connecting to a control printed circuit board provided outside the case are mounted. Further, a temperature sensor for detecting the temperature inside the case, particularly the temperature around the magnetic head and the magnetic disk is mounted at the base end of the main FPC. Then, according to the temperature detected by the temperature sensor, the control of the write current of the magnetic head to the magnetic disk and the setting of the analog filter coefficient are performed.

[0005]

In the above-described magnetic disk drive, what changes with temperature is the characteristics of the magnetic head and the magnetic disk, and it is necessary to accurately control and set the write current and analog filter coefficient of the magnetic head. In this case, it is necessary to accurately detect the ambient temperature of the magnetic head and the magnetic disk.

[0006] However, as described above, the temperature sensor is mounted on the base end of the main FPC together with the head IC. The head IC generates heat during the operation of the magnetic disk drive, and the heat is transmitted to the temperature sensor through the backing plate of the main FPC. During operation of the magnetic disk drive, the spindle motor also generates heat, and the heat is transmitted to the temperature sensor through the case and the backing plate of the main FPC. Therefore, the temperature detected by the temperature sensor is the actual ambient temperature of the magnetic head and the magnetic disk, that is,
It will be higher than the temperature inside the case. as a result,
It is difficult to accurately control and set the write current of the magnetic head and the analog filter coefficient.

An object of the present invention is to provide a magnetic disk drive capable of accurately detecting the ambient temperature of a magnetic head and a magnetic disk.

[0008]

In order to achieve the above object, a magnetic disk drive according to the present invention comprises: a magnetic disk on which desired information is recorded; a spindle motor for supporting and rotating the magnetic disk; A magnetic head for recording and reproducing information on and from a magnetic disk; a head actuator for moving and positioning the magnetic head to an arbitrary position with respect to the magnetic disk; and a base on which the spindle motor and the head actuator are mounted. A flexible printed circuit board having a base, one end connected to the head actuator, and a base mounted on the base via a metal backing plate; and a base of the flexible printed circuit board. On the end, a head I for amplifying a signal from the magnetic head
C, and a temperature sensor for detecting a temperature around the magnetic head and the magnetic disk are mounted, and the backing plate has an opening formed at a position facing the temperature sensor. I have.

According to the magnetic disk drive having the above structure, an air layer having a low thermal conductivity is formed between the backing plate and the temperature sensor and between the base and the temperature sensor by the opening. Therefore, the heat transmitted from the head IC or the spindle motor to the temperature sensor through the backing plate and the base is reduced, and the temperature sensor can accurately detect the ambient temperature of the magnetic head and the magnetic disk.

According to another magnetic disk drive of the present invention, a head IC for amplifying a signal from the magnetic head and a temperature around the magnetic head and the magnetic disk are provided on the base end of the flexible printed circuit board. And a temperature sensor for detecting the temperature of the backing plate, wherein the base is formed at a position facing the temperature sensor and has a recess opened toward the backing plate.

According to still another magnetic disk drive of the present invention, a head IC for amplifying a signal from a magnetic head and a temperature around the magnetic head and the magnetic disk are provided on a base end of the flexible printed circuit board. And a heat insulating layer that regulates the transfer of heat from the base to the temperature sensor is provided between the base and the backing plate.

Further, according to another magnetic disk drive of the present invention, the base end of the flexible printed circuit board has an upright portion bent and raised in a direction away from the base shell together with the backing plate, The magnetic head and the temperature sensor for detecting the temperature around the magnetic disk are mounted on the upright portion.

In any of the magnetic disk devices configured as described above, the heat transmitted to the temperature sensor through the base can be reduced, and the ambient temperature of the magnetic head and the magnetic disk can be accurately detected by the temperature sensor. Becomes

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a hard disk drive (hereinafter, referred to as an HDD) as a magnetic disk device will be described in detail with reference to the drawings.

As shown in FIG. 1, the HDD has a rectangular box-shaped case 12 having an open upper surface, and a top cover 14 which is screwed to the case with a plurality of screws 11 and closes an upper end opening of the case. are doing. The case 12 is formed of a metal such as aluminum, and its bottom wall functions as a base.

In the case 12, a magnetic disk 16 as a magnetic recording medium, a spindle motor 18 for supporting and rotating the magnetic disk, a plurality of magnetic heads for recording and reproducing information on and from the magnetic disk, A carriage assembly 22 for supporting the head movably with respect to the magnetic disk 16, a voice coil motor (hereinafter referred to as VCM) 24 for rotating and positioning the carriage assembly, and a magnetic head for moving to the outermost periphery of the magnetic disk. A ramp load mechanism 25 for holding the head at a position separated from the magnetic disk and a substrate unit 21 having a head IC and the like are housed.

On the outer surface of the bottom wall of the case 12, a spindle motor 18, a VCM 2
4, and a printed circuit board (not shown) for controlling the operation of the magnetic head are screwed.

The magnetic disk 16 has a diameter of 65 mm (2.
5 inches) and has a magnetic recording layer on the upper and lower surfaces. The magnetic disk 16 is coaxially fitted to a hub (not shown) of a spindle motor 18 and is clamped by a clamp spring 17 to be driven to rotate at a predetermined speed.

The carriage assembly 22 includes the case 1
The bearing assembly includes a bearing assembly fixed on the bottom wall, two arms extending from the bearing assembly, and two magnetic head assemblies supported by each arm.
Each magnetic head assembly 36 includes an elongated suspension 38 formed by a leaf spring, and a magnetic head 40 fixed to a tip of the suspension. The carriage assembly 22 has a support frame 43 extending from the bearing assembly 26 in a direction opposite to the arm 32,
A voice coil (not shown) constituting a part of the VCM 24 is fixed to the support frame.

The magnetic disk 16 is located between the two arms 32 when the carriage assembly 22 configured as described above is incorporated in the case 12.
Then, the magnetic head 40 attached to the arm 32
Face the upper and lower surfaces of the magnetic disk 16, respectively, and sandwich the magnetic disk 16 from both sides.

The voice coil fixed to the support frame 43 of the carriage assembly 22 is
The VCM 24 is located between a pair of yokes 48 fixed on a bottom wall of the VCM 24 and these yokes and a magnet (not shown) fixed to one of the yokes. When the voice coil is energized, the carriage assembly 22 rotates, and the magnetic head 40
Is moved and positioned on the desired track. Note that the carriage assembly 22 and the VCM
Reference numeral 24 functions as a head actuator in the present invention.

On the other hand, the board unit 21 has a main flexible printed circuit board (hereinafter, referred to as a main FPC) 54. And the main FPC 54
It has an extended end 54a attached to the carriage assembly 22, and a base end 54b attached to the bottom wall of the case 12 via a backing plate described later. The extension end 54a is electrically connected to the magnetic head 40 via a relay FPC (not shown) attached to each arm 32 and the suspension 38. The main FPC
Reference numeral 54 denotes a conductive film except for a base film (base layer) made of an insulating material such as polyimide, a conductive pattern formed by patterning a copper foil formed on the base film, and a pad portion of the conductive pattern. And a cover layer made of an insulating material that covers the base film.

As shown in FIGS. 1 and 2, the main FP
A head IC 60 for amplifying a signal from the magnetic head 40, a connector 62 for connecting a printed circuit board provided on the outer surface side of the case 12 to the main FPC 54, and other electronic components are provided on the base end 54b of the C54. Parts are mounted. The magnetic head 40 is located on the base end 54b.
And the temperature around the magnetic disk 16 as Case 1
2 is mounted with a temperature sensor 64 for detecting the internal temperature.

A backing plate 65 made of a metal such as SUS304 having a thickness of 0.5 mm is provided on the back side of the base end portion 54b.
Is affixed. The base end portion 54b is mounted on the bottom wall of the case 12 via a backing plate 65 by screwing or an adhesive. In addition, backing plate 6
An opening 66 is formed in 5, and is located opposite to the temperature sensor 64. The opening 66 has a cross-sectional area larger than the plane area of the temperature sensor 54, and the temperature sensor is arranged so as to entirely overlap the opening 66.

According to the HDD configured as described above,
During operation, the temperature sensor 64 detects the temperature inside the case 12 as the temperature around the magnetic head 40 and the magnetic disk 16. Then, control of the write current of the magnetic head and setting of the analog filter coefficient are performed according to the detected temperature.

At this time, the temperature sensor 64 is arranged so as to face the opening 66 formed in the backing plate 65, and between the backing plate and the temperature sensor, and between the bottom wall of the case 12 and the temperature sensor. The opening 66 forms an air layer having a low thermal conductivity. Therefore, the heat transmitted from the head IC 60 and the spindle motor 18 to the temperature sensor 64 through the backing plate 65 and the case 12 is reduced, and the temperature sensor accurately detects the temperature in the case 12, that is, the ambient temperature of the magnetic head 40 and the magnetic disk 16. Can be detected.
Therefore, according to the temperature detected by the temperature sensor 64, it is possible to accurately control and set the write current of the magnetic head, the analog filter coefficient, and the like. With this, HD
D can be operated under optimal conditions according to the ambient temperature.

Next, another embodiment according to the present invention will be described. In other embodiments described later, the same parts as those in the above-described first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described in detail.

As shown in FIG. 3, according to the second embodiment of the present invention, at the bottom wall of the case 12, at a position facing the temperature sensor 64, a recess opened toward the backing plate 65. 68 are formed. By providing such a recess 68, the temperature sensor 64
Can be reduced, and the ambient temperature of the magnetic head 40 and the magnetic disk 16 can be accurately detected by the temperature sensor.

According to the third embodiment of the present invention shown in FIG. 4, the thermal conductivity between the backing plate 65 and the bottom wall of the case 12 is 0.0001 to 0.01 (cal / cm · cm). S.
C) as a heat insulating layer, for example, a thickness of 0.5 to 1.5 mm
A heat insulation layer 70 made of Teflon (registered trademark) is provided. In this case, the heat insulating layer 70 is screwed to the bottom wall of the case 12 together with the base end 54b of the main FPC 54 and the backing plate 65, or is fixed by an adhesive.

By providing such a heat insulating layer 70, the heat transmitted to the temperature sensor 64 through the case 12 can be reduced, and the ambient temperature of the magnetic head 40 and the magnetic disk 16 can be accurately detected by the temperature sensor. be able to. In the first embodiment, the heat insulating layer 70 may be used in combination. In this case,
Heat transmitted to the temperature sensor 64 through the case 12 can be further reduced.

According to the third embodiment of the present invention shown in FIG. 4, the base end 54b of the main FPC 54 is
5 has an upright portion 72 bent and raised substantially at right angles to the bottom surface of the case 12, and the temperature sensor 64 is mounted on the distal end side of the upright portion 72. With such a configuration, the temperature sensor 64 can be separated from the bottom wall of the case 12, and accordingly, the heat transmitted to the temperature sensor 64 through the case 12 is reduced, and the magnetic head 40 and the magnetic disk The ambient temperature of 16 can be accurately detected.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, the shape, material, and the like of each member can be selected as needed. The apparatus may be configured by combining a plurality of the above-described embodiments. For example, a magnetic disk apparatus may be configured by combining the first, third, and fourth embodiments.

[0033]

As described above in detail, according to the present invention, the heat transmitted to the temperature sensor through the backing plate and the base can be reduced, and the ambient temperature of the magnetic head and the magnetic disk can be accurately detected. It is possible to provide a magnetic disk device capable of accurately controlling and setting a write current of a magnetic head, an analog filter coefficient, and the like according to a temperature detected by a sensor.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an HDD according to an embodiment of the present invention.

FIG. 2 is an exemplary sectional view showing a part of a board unit provided in the HDD;

FIG. 3 is a sectional view showing a part of a substrate unit according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a part of a substrate unit according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a part of a substrate unit according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 ... Case 16 ... Magnetic disk 18 ... Spindle motor 21 ... Board unit 22 ... Carriage assembly 24 ... Voice coil motor 40 ... Magnetic head 54 ... Main FPC 54a ... Extension end 54b ... Base end 65 ... Backing plate 66 ... Open Hole 68 ... recess 70 ... heat insulation layer 72 ... standing part

Claims (6)

[Claims] A magnetic disk on which desired information is recorded; a spindle motor for supporting and rotating the magnetic disk; a magnetic head for recording / reproducing information on / from the magnetic disk; A head actuator that moves and positions the magnetic head to an arbitrary position, a base on which the spindle motor and the head actuator are mounted, one end connected to the head actuator, and a metal backing plate. A flexible printed circuit board having a base end attached to the base, and a head IC for amplifying a signal from the magnetic head on the base end of the flexible printed circuit board; A temperature sensor for detecting the temperature around the head and the magnetic disk is mounted. A magnetic disk apparatus characterized by having an opening formed at a position facing the temperature sensor. 2. The apparatus according to claim 1, wherein said aperture has a cross-sectional area larger than a plane area of said temperature sensor.
3. The magnetic disk drive according to claim 1. A magnetic disk on which desired information is recorded; a spindle motor for supporting and rotating the magnetic disk; a magnetic head for recording / reproducing information on / from the magnetic disk; A head actuator that moves and positions the magnetic head to an arbitrary position, a base on which the spindle motor and the head actuator are mounted, one end connected to the head actuator, and a metal backing plate. A flexible printed circuit board having a base end attached to the base, and a head IC for amplifying a signal from the magnetic head on the base end of the flexible printed circuit board; A temperature sensor for detecting the temperature around the head and the magnetic disk is mounted, and A magnetic disk apparatus characterized by having a recess that opens toward the backing plate together is formed at a position facing the temperature sensor. A magnetic disk on which desired information is recorded; a spindle motor for supporting and rotating the magnetic disk; a magnetic head for recording and reproducing information on the magnetic disk; A head actuator that moves and positions the magnetic head to an arbitrary position, a base on which the spindle motor and the head actuator are mounted, one end connected to the head actuator, and a metal backing plate. A flexible printed circuit board having a base end attached to the base, and a head IC for amplifying a signal from the magnetic head on the base end of the flexible printed circuit board; A temperature sensor for detecting the temperature around the head and the magnetic disk is mounted, and Between the backing plate, the magnetic disk device characterized by heat insulating layer for regulating the transfer of heat to the temperature sensor from the base are provided. 5. The heat insulating layer according to claim 1, wherein the heat insulating layer is in a range of 0.0001 to 0.01.
5. The magnetic disk drive according to claim 4, having a thermal conductivity of (cal / cm.S..degree. C.). 6. A magnetic disk on which desired information is recorded, a spindle motor for supporting and rotating the magnetic disk, a magnetic head for recording and reproducing information on the magnetic disk, A head actuator for moving and positioning the magnetic head to an arbitrary position, a base on which the spindle motor and the head actuator are mounted, one end connected to the head actuator, and a metal backing plate. A flexible printed circuit board having a base end attached to the base.The base end of the flexible printed circuit board is bent and raised in a direction away from the base together with the backing plate. A standing portion on which the temperature around the magnetic head and the magnetic disk is detected Magnetic disk apparatus characterized by the temperature sensor is mounted that.