JPH0546947A - Magnetic head device - Google Patents

Abstract

PURPOSE:To enhance the S/N of the title head device and to prevent the electrostatic breakdown of the title head device by a method wherein an MR head and a head support mechanism are insulated electrically by using an insulating layer. CONSTITUTION:An MR head is installed on one main face of a slider 2 which is supported by a head support mechanism 1. The support mechanism 1 is composed of a load beam 4 and a thin-sheet gimbals at its tip. The MR head 3 makes a magnetic gap face a face coming into contact with a hard disk; it is formed on one side face in the short-side direction of the slider 2. In the MR head 3, a first thin film magnetic core and a second thin-film magnetic core are faced with the slider 2, and are stacked and formed at a prescribed interval. An insulating layer 16 is formed between the slider 2 and the first thin film magnetic core which has been grounded. Consequently, a noise which is propagated from a circuit system or the like via the head support mechanism 1 is cut off by the insulating layer 16, and the accurate replay and readout operation of the title head device can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head device having a magnetoresistive head mounted on a slider as a reproducing head for a hard disk, for example.

[0002]

2. Description of the Related Art For example, as a reproducing head for a hard disk drive, a magnetoresistive effect type magnetic head (hereinafter referred to as an MR head) is becoming mainstream because of its excellent short wavelength sensitivity. To read the information recorded on the hard disk using this MR head,
Al ₂ supported by an elastic member called a gimbal
This is carried out by mounting the MR head on a slider made of an O ₃ -TiC substrate or the like and allowing the MR head to float above a rotating hard disk with a minute gap.

By the way, in the above-mentioned MR head, the magnetic resistance of the electric charges charged on the disk surface due to the rotation of the hard disk, which faces the contact surface with the hard disk at the time of starting or stopping the operation, that is, the ABS (air bearing surface) surface. An effect (electrostatic destruction) that the MR magnetic sensing part or the tip electrode is destroyed by jumping into the effect magnetic sensitive part (hereinafter referred to as MR magnetic sensing part) or the tip electrode of the MR magnetic sensing part occurs. Cheap.

For this reason, conventionally, a structure has been adopted in which a conductor that positively receives the discharge charge from the hard disk is provided facing the ABS surface and the discharge charge is flowed directly from the conductor to the ground portion. That is, one thin film magnetic core of a pair of thin film magnetic cores sandwiching the MR sensitive portions laminated respectively at the front end portion and the rear end portion and a ground side electrode facing the ABS surface of the MR sensitive portion are provided. By conducting the electric current, the current due to the electric charge discharged from the hard disk is grounded.

[0005]

However, with the above-mentioned configuration, wideband noise generated from, for example, the drive system and the circuit system in the drive device propagates to the MR magnetic sensing section through the gimbal or slider of the head support mechanism. The inconvenience arises. This noise becomes a factor that deteriorates the signal-to-noise ratio. Therefore, in order to read an accurate reproduced signal, it is desirable to reliably block the propagation of noise from the system in the drive device. Therefore, the present invention has been proposed in view of such conventional technical problems, and provides a magnetic head device capable of reliably blocking noise from a system in a hard disk drive device and improving a signal-noise ratio. The purpose is to do.

[0006]

In order to achieve the above object, the present invention provides a magnetoresistive effect in which a magnetoresistive effect sensitive section is sandwiched by a pair of thin film magnetic cores, at least one of which is grounded. In a magnetic head device in which a type magnetic head is integrally formed with a slider supported by a head support mechanism, the magnetoresistive effect magnetic head and the head support mechanism are electrically insulated, and noise propagation is blocked. It is characterized by.

Further, according to the present invention, in the magnetic head device according to the first aspect, an insulating layer is provided between the head supporting mechanism and the slider.

[0008]

In the first aspect of the invention, since the magnetoresistive effect magnetic head and the head support mechanism are electrically insulated from each other, noise propagated through the head support mechanism from the drive system or circuit system in the drive device. Is cut off, and the resistance effect type magnetic head cannot be reached.

In the second aspect of the invention, since the insulating layer is provided between the slider on which the magnetoresistive effect magnetic head is formed and the head support mechanism, the magnetic field is propagated through the head support mechanism from the drive system or the circuit system. The incoming noise is surely blocked by this insulating layer and does not reach the magnetoresistive head. Therefore, the reliability of the signal to noise ratio is improved,
The reproduced signal can be read accurately.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

First Embodiment As shown in FIG. 1, the magnetic head device according to the present embodiment has an MR head (magnetoresistive effect type magnetic) as a reproducing head on one main surface of a slider 2 supported by a head supporting mechanism 1. A head) 3 is formed. The head support mechanism 1 includes a mounting plate (not shown) fixed to an arm portion of a drive device, a load beam 4 whose base end portion is fixed to the arm portion by the mounting plate, and the load beam 4 And a gimbal 5 made of a thin plate provided at the tip end of each of these, and they are assembled by spot welding.

Mounting plate and load beam 4
Moves in conjunction with the arm portion to move the MR head 3 mounted on the slider 2 to a desired recording track position of the hard disk in the radial direction of the disk to access it. The gimbal 5 serves as a cushion between the arm portion and the slider 2, and ensures a stable flying posture of the slider 2.

On the other hand, the slider 2 includes, for example, Al ₂ O ₃ −.
An air inflow groove 6 made of a non-magnetic and electrically conductive material such as TiC is provided on the surface facing the hard disk to float the slider with respect to the hard disk with a minute gap. The slider 2 is attached to the gimbal 5 and is supported in a so-called point contact state by a protrusion called a dimple provided on the gimbal 5. Therefore, even if an inadvertent external force is applied to the slider 2, the flying posture of the slider 2 is changed by the dimples so that a large impact is not given to the hard disk.

The MR head 3 is provided on one side surface of the slider 2 in the short side direction so that a magnetic gap g acting as a reproducing gap is desired on the ABS surface 7 which is a contact surface with the hard disk. ing. This MR
As shown in FIGS. 2 and 3, the head 3 includes a first thin film magnetic core 8 and a second thin film magnetic core 8 that form a magnetic gap g between the front ends.
The thin film magnetic core 9 is formed so as to face the slider 2 with a predetermined gap.

The first thin-film magnetic core 8 is provided so that one end thereof faces the ABS surface 7 and extends in a direction substantially orthogonal to the ABS surface 7. On the other hand, the second thin-film magnetic core 9 is provided so as to extend in a direction substantially orthogonal to the ABS surface 7 with one end thereof facing the ABS surface 7 and faces the ABS surface 7. The front end portion is bent at a right angle so that the gap with the first thin film magnetic core 8 is narrowed. A magnetic gap g functioning as a reproducing gap is formed between the bent front ends so as to face the ABS surface 4. Further, the second thin film magnetic core 9 is magnetically connected to the first thin film magnetic core 8 at the rear end portion. A protective layer 17 for protecting the MR head 3 is provided on the second thin film magnetic core 9.

An MR magnetic sensitive section 10, which is a magnetoresistive magnetic sensitive section, is provided between the first thin-film magnetic core 8 and the second thin-film magnetic core 9 facing the ABS surface 7. MR
The magnetically sensitive portion 10 is formed as an elongated rectangular pattern in a plan view, and its longitudinal direction is provided so as to match the direction orthogonal to the ABS surface 7. And this MR magnetic sensing unit 10
Of the first thin-film magnetic core 8 and the second thin-film magnetic core 8 whose rear edges are opposed to each other while the one edge thereof faces the ABS surface 7.
The thin film magnetic core 9 is located at almost the midway point.
The MR magnetic sensing unit 10 is electrically connected to the first thin film magnetic core 8 by an insulating layer 11 provided between the first thin film magnetic core 8 and the second thin film magnetic core 9 in order to insulate the MR thin film magnetic unit 10 from the first thin film magnetic core 8. Is electrically isolated. Also, the MR
In order to avoid the occurrence of Barkhausen noise, it is desirable that the magnetic sensing section 10 be formed by laminating a pair of MR thin films that are magnetostatically coupled via a nonmagnetic insulating layer made of, for example, SiO ₂ .

A pair of electrodes 12a and 12b (hereinafter referred to as ABS surface 7) for passing a sense current from a constant current source (not shown) are provided at the front end portion and the rear end portion of the MR magnetic sensing portion 10.
The electrode 11a provided on the side is referred to as a front end electrode 12a, and the electrode 12b provided on the rear end side is referred to as a rear end electrode 12b. ) Are electrically connected to the MR magnetic sensing part 10 and are laminated. The tip electrode 12a is provided so that one end thereof faces the ABS surface 7 and the second thin film magnetic core 9 is provided.
It is magnetically insulated from but electrically connected to this second
The thin film magnetic core 9 is formed as a continuous film up to the position extending to the back side. The tip electrode 12a is connected to the ground side M through the conductor pattern 9a extending from the back side of the second thin film magnetic core 9 which is electrically conductive.
It is connected to the R terminal 13. The tip electrode 12
a is, for example, Ti, Cr, which is non-magnetic and has excellent conductivity,
A material having good moisture resistance such as Mo, W, C, and stainless is used.

On the other hand, the rear end electrode 12b is formed as a conductor pattern having a rectangular shape in a plan view, and a part of the rear end electrode 12b is provided so as to cross the MR magnetic sensing section 10. The end 14 of the conductor pattern extending to the back side from a part of the rear end electrode 12b serves as a current source side terminal for flowing a sense current to the MR magnetic sensing part 10.

The front electrode 12a and the rear electrode 1 are
Between 2b, when the MR magnetic sensing section 10 is energized, this M
A bias conductor 15 is provided which gives a magnetized state in a desired direction to the R magnetic sensing section 10 so as to operate in a characteristic region in which the magnetoresistance characteristic exhibits excellent linearity and high sensitivity. The bias conductor 15 is provided between the pair of electrodes 12a and 12b so as to cross the MR magnetic sensing part 10, and both ends thereof are drawn out to the back side. The ends 15a and 15b pulled out to the back side serve as terminals for passing a current through the bias conductor 15.

In particular, in the magnetic head device of this embodiment, the MR head 3 and the head support mechanism 1 are electrically insulated. That is, by providing the insulating layer 16 between the slider 2 and the first thin film magnetic core 8, the MR head 3 and the head support mechanism 1 are electrically insulated. As a result, noise propagated through the head support mechanism 1 from, for example, a drive system or a circuit system in the drive device is reliably blocked by the insulating layer 16. This prevents noise from entering the MR head 3, improves the signal-to-noise ratio during reading, and enables accurate reading of the reproduced signal.

Further, in the magnetic head device of this example, since the tip electrode 12a and the second thin film magnetic core 9 are electrically connected to each other and are grounded, the electric charge charged on the hard disk is in the magnetic gap portion. Even if it jumps in, it flows to the grounded MR terminal 13 via any of the first thin film magnetic core 8, the second thin film magnetic core 9, and the tip electrode 12a. As a result, a discharge current does not flow to the MR magnetic sensing unit 10, so that a damage accident due to the discharge of the MR magnetic sensing unit 10, that is, electrostatic breakdown is avoided.

Second Embodiment A magnetic head device according to this embodiment is mainly composed of a tip electrode 12.
The MR head 3 is mounted on the slider 2 supported by the head supporting mechanism 1 as in the magnetic head device of the first embodiment except that a is not electrically connected to the second thin film magnetic core 9. In addition, the insulating layer 16 for blocking the propagation of noise from the system in the drive device is provided between the MR head 3 and the slider 2. Therefore, in this example, only parts different from the first embodiment will be described.

In the magnetic head device of this embodiment, the second thin film magnetic core 9 is provided straight in the direction perpendicular to the ABS surface 7 without bending at the front end of the ABS surface 7. The facing distance between the first thin film magnetic core 8 and the second thin film magnetic core 9 is larger than that of the magnetic head of FIG. And further, this second thin film magnetic core 9
Is on the back side with respect to the first thin film magnetic core 8.
By being embedded in the hole 1a formed in the thin film magnetic core 9, the magnetic conduction is established.

The front electrode 12a is the rear electrode 12b.
It is formed as a conductor pattern of a plane rectangular shape larger than the above, and a part thereof is provided so as to cross the MR magnetic sensing part 10. Then, the end portion 18 of the conductor pattern that is drawn out from the rear end electrode 12b to the back side serves as the MR terminal on the ground side. The MR terminal has a second
Conductor pattern 9 extending from the thin film magnetic core 9 to the back side
a is electrically connected.

In the magnetic head device of this embodiment,
Similar to the magnetic head device of the first embodiment, the insulating layer 16 provided between the MR head 3 and the slider 2 ensures that the propagation of noise from the drive system / circuit system in the drive device is blocked. Therefore, the reliability of the signal noise ratio at the time of reading is ensured. Also in the magnetic head device of this embodiment, since the electrically conductive first thin film magnetic core 8 and second conductive thin film magnetic core 9 are grounded, the electric potential of the hard disk is zero. It flows preferentially to the first thin film magnetic core 8 or the second thin film magnetic core 9. Therefore, the discharge current does not flow to the tip electrode 12a or the MR magnetic sensing section 10 whose one end faces the ABS surface 7, and electrostatic breakdown does not occur.

Embodiment 3 In the magnetic head device of this embodiment, the MR head 3 is mounted on the slider 2 supported by the head support mechanism 1 similarly to the magnetic head device of embodiment 1, but the gimbal 5 is used. Is different from the above in that an insulating layer 16 for blocking the propagation of noise from the system in the drive device is provided at the connection portion of the slider 2. Other configurations, that is, the MR head 3
Has the same configuration as that of the first embodiment.

Therefore, in the magnetic head device of this embodiment, the magnetic field is propagated from the drive system / circuit system in the drive device through the head support mechanism 1 over the entire main surface of the slider 2 to which the gimbal 5 is fixed. Noise is reliably blocked by this insulating layer 16. As a result, the propagation of noise to the MR head 3 is blocked, the signal-to-noise ratio at the time of reading is improved, and an accurate reproduced signal can be read.

In the first to third embodiments described above, the insulating layer 16 is provided between the head supporting mechanism 1 and the slider 2 or between the slider 2 and the MR head 3 to block noise from the system in the drive device. I tried to do it,
Even if the head support mechanism 1 itself is made of an insulating material that blocks noise, the same effect can be obtained.

[0029]

As is apparent from the above description, the first
According to the magnetic head device of the present invention, since the MR head and the head support mechanism are electrically insulated, the noise propagated through the head support mechanism from the drive system, the circuit system, or the like in the drive device is reduced. It does not reach the MR head. Therefore, the signal-to-noise ratio can be improved and an accurate reproduced signal can be read.
In addition, since at least one of the thin film magnetic cores that sandwich the MR magnetic sensitive portion is grounded, it is possible to prevent electric charge from the medium from jumping into the MR magnetic sensitive portion, and avoid electrostatic breakdown. it can.

Further, according to the magnetic head device of the second invention, since the insulating layer is provided between the head supporting mechanism and the slider on which the MR head is formed, the magnetic head device can be used in a drive system or a circuit system in the drive device. The noise transmitted through the head support mechanism can be reliably blocked by this insulating layer.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire magnetic head device to which a first invention is applied.

FIG. 2 is an enlarged cross-sectional view of an essential part showing an enlarged MR head portion of the magnetic head device to which the first invention is applied.

FIG. 3 is a schematic plan view of the MR head of FIG.

FIG. 4 is an enlarged cross-sectional view of an essential part showing an enlarged MR head portion of another example of the magnetic head device to which the first invention is applied.

5 is a schematic plan view of the MR head of FIG.

FIG. 6 is an enlarged sectional view of an essential part showing an enlarged MR head portion of a magnetic head device to which the second invention is applied.

FIG. 7 is a perspective view showing an entire magnetic head device to which the second invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Head support mechanism 2 ... Slider 3 ... MR head (magnetoresistive effect magnetic head) 5 ... Gimbal 7 ... ABS surface 8 ... 1st thin film magnetic core 9 ... -Second thin film magnetic core 10 ... MR magnetic sensing part 12a ... Front end electrode 12b ... Rear end electrode 15 ... Bias conductor 16 ... Insulating layer

Claims (2)

[Claims] 1. A magnetoresistive effect magnetic head comprising a pair of thin film magnetic cores, at least one of which is grounded, sandwiching a magnetoresistive effect magnetic sensitive portion, is integrally formed on a slider supported by a head supporting mechanism. In the above magnetic head device, the magnetoresistive head and the head support mechanism are electrically insulated from each other, and noise propagation is blocked. 2. The magnetic head device according to claim 1, wherein an insulating layer is provided between the head support mechanism and the slider.