JPH1055518A - Thin-film magnetic head and magnetic disk drive - Google Patents

Abstract

(57) [Problem] To provide a thin-film magnetic head that can be easily assembled without complicating the structure thereof and that a discharge suppressing action can be obtained. A thin-film magnetoresistive element for reading, comprising a magnetoresistive conversion section sandwiched between two shield films, has at least one shield film at both ends of the magnetoresistance conversion section. A thin-film magnetic head electrically connected to one of the terminals 9 and 10 provided. Further, the magnetic film 13 of the thin-film magnetic transducer for writing may be electrically connected to the one terminal, or both may be electrically connected to the one terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating type thin film magnetic head used for a magnetic disk device and the like, and a magnetic disk device having the thin film magnetic head.

[0002]

2. Description of the Related Art Today's small HDD (magnetic disk drive)
Uses a single power supply of 5 volts or 12 volts of a personal computer power supply in consideration of mounting on a personal computer, and also uses a single power supply of 5 volts or 12 volts for a read / write IC (integrated circuit) of a small HDD. On the other hand, a thin-film magnetic head includes a thin-film magnetic transducer for writing and a thin-film magneto-resistive element for reading. Since the thin-film magnetic transducer uses the above-described read / write IC, the coil of the thin-film magnetic transducer is always biased at a constant voltage, and a capacitor is generated between the magnetic film and the coil constituting the magnetic circuit. The charge always accumulates in one direction due to the voltage. Further, in the thin-film magnetoresistive element, since the magnetoresistive converter is sandwiched between two shield films, a capacitor is generated between the shield film and the magnetoresistive converter. The electric charge accumulated in the capacitor is discharged by contact between the pole of the magnetic film or the shield film and the magnetic recording medium. This discharge generates noise and causes an error in read data.

In order to prevent this discharge, Japanese Patent Laid-Open Publication No.
In the invention described in JP-A-48-48, the bias voltage of the thin-film magnetic head is made equal to the voltage of the magnetic recording medium so that no discharge occurs.

Further, the invention described in Japanese Patent Application Laid-Open No. 07-37226 uses a slider having an insulating film on the surface of a conductive substrate, and a conductive lead wire is formed from the magnetic film of the thin film magnetic transducer formed thereon. And penetrate it through the insulating film and connect it to the conductive substrate. This is to prevent the electric charge accumulated in the capacitor generated between the magnetic film and the coil from being discharged to the medium, flowing from the magnetic film through the conductive lead line to the conductive base, and not causing discharge. It was made.

[0005]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 2-246.
The conventional technology described in Japanese Patent Application Laid-Open No. 048-048 discloses that a rotating magnetic recording medium has the same bias potential as a thin film magnetic head.
The spindle contact section becomes complicated, and the frame needs to be applied with a voltage applied to the inner frame and the GND (ground) side for the outer frame with a double structure. Further, the circuit of the readout IC with the sense current circuit for flowing the sense current to the magnetoresistive conversion element becomes complicated. Therefore, there has been a problem that the structure of the magnetic disk device becomes complicated and large, and the cost increases accordingly.

The prior art described in Japanese Patent Application Laid-Open No. 07-37226 adds a lead line to a thin-film magnetic head,
In order to flow the capacitor generated between the magnetic film and the coil to the slider, it is necessary to keep the slider at GND, and the slider and the support spring are bonded with a conductive resin, and reliability such as bonding strength is secured. There is a problem that an assembly structure cannot be easily obtained.

A first object of the present invention is to provide a thin-film magnetic head which has a simple structure, is easy to assemble, and has a discharge suppressing action. A second object of the present invention is to provide a magnetic disk drive using such a thin-film magnetic head.

[0008]

In order to achieve the first object, a thin-film magnetic head according to the present invention comprises a coil and a thin-film magnetic transducer for writing having a magnetic film interlinked with the coil to form a magnetic circuit. And a read-out thin-film magnetoresistive element having a magnetoresistive conversion portion sandwiched between the two shield films and the two shield films. Is electrically connected to one of the terminals provided in the terminal. In this thin-film magnetic head, it is preferable that at least one shield film of the thin-film magnetic resistance element is electrically connected to the one terminal. Preferably, the one terminal is connected to the ground side of the readout integrated circuit.

In order to achieve the first object,
A thin-film magnetic head according to the present invention includes a write thin-film magnetic transducer having a coil, a magnetic film linked to the coil and forming a magnetic circuit, two shield films, and a magnetic film sandwiched between the two shield films. A read-out thin-film magnetoresistive element having a resistance conversion section, wherein at least one shield film of the thin-film magnetoresistance element is electrically connected to one of terminals provided at both ends of the magnetoresistance conversion section. It is like that. It is preferable that one terminal of the thin-film magnetic head is connected to the ground side of the readout integrated circuit.

In order to achieve the second object,
A magnetic disk drive according to the present invention includes at least one magnetic recording medium, a thin-film magnetic head arranged to face the magnetic recording medium, and for recording and reproducing information on and from the magnetic recording medium.
A thin film magnetic head; a read integrated circuit connected to the thin film magnetic head; a unit for positioning the thin film magnetic head at a desired position on the magnetic recording medium; and a control unit for controlling these units. The thin film magnetic head described above is used. In this magnetic disk drive, it is preferable that one terminal is connected to the ground side of the readout integrated circuit.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a circuit in which a thin-film magnetic head according to a first embodiment of the present invention and a reading IC are connected.

In FIG. 1, 1 is a thin film magnetic head, 2 is a read IC, 3 is a transistor, and 4 is a read I
GND terminal in C, 5 is a signal line for carrying a read signal,
Reference numeral 20 denotes a magnetic recording medium. The thin-film magnetoresistive element 17
Magnetoresistance converter 8, shield films 7, 11, electrodes 14, 1
6, terminals 9, 10 and the like. Terminal 9 is signal line 5
The terminal 10 is electrically connected to the GND terminal 4 of the read IC through the signal line 5, and the sense current 18 is supplied to the magnetoresistive converter 8 through the terminal 9. . One of the two shield films also serves as a lower magnetic film of the thin-film magnetic transducer. Thin film magnetic transducer 6
Is composed of a lower magnetic film also used as the shield film 7, an upper magnetic film 13, a coil 12, and the like forming a magnetic circuit with the lower magnetic film. Reference numeral 15 denotes a lead line described later.

FIG. 3 is a schematic cross-sectional view of a read thin-film magnetoresistive element of a thin-film magnetic head and a write thin-film magnetic transducer, and FIG. 2 is a perspective plan view of the read thin-film magnetoresistive element of the thin-film magnetic head. FIG. Each drawing shows the outline of the structure, and the dimensions of each part are exaggerated.

As shown in FIG. 3, the upper magnetic film 13 and the shield films 7 and 11 are usually made of permalloy or the like, and pole portions 101 and 102 whose front end portions on the magnetic recording medium facing surface 301 side constitute a magnetic conversion gap. The lower magnetic film (shown as the shield film 7) and the rear side of the upper magnetic film 13 are coupled to form a magnetic circuit. The pole portions 101 and 102 are made of a gap film 20 made of alumina or the like.
Separated by one. The coil 12 includes the upper magnetic film 1
A spiral shape surrounds the joint between the lower magnetic film 3 and the lower magnetic film. The coil 12, the upper magnetic film 13, and the lower magnetic film are insulated by an insulating film 202 such as a resin. 203 is a protective film made of alumina or the like.

The magnetoresistive converter 8 of the thin-film magnetoresistive element comprises:
They are sandwiched between the shield films 7 and 11 and are protected and insulated by protective films 203, 204, 205 and 206 made of alumina or the like. The electrode 14 is a conductor such as gold or tantalum, and is electrically connected to the terminal 10 which is a conductor such as copper (the electrode 16 and the terminal 9 shown in FIG. the same). The lower magnetic film (shield film 7) and the terminal 10 are electrically connected by a lead 15 made of a conductor.

Returning to FIG. 1, the description will be continued. With the above configuration, the lower magnetic film and the upper magnetic film 13 are electrically connected to the GND terminal 4 of the reading IC 2 via the lead 15 and the terminal 10. Therefore, the coil 12 and the upper magnetic film 1
3. The capacitance of the capacitor generated between the lower magnetic film and the electrode 14 becomes substantially zero due to the lead line 15, so that even if the coil 12 is biased at a constant voltage, no charge is stored in the capacitor, and the pole portion 101, 102
No electric charge is generated, and no discharge occurs from the pole portions 101 and 102 to the magnetic recording medium 20 and the like.

As described above, the lead 15 is connected to the protective film 20.
Since it is completely covered with 3, 206 and the like, the electrical connection is completed internally, and there is no room for an electrical connection failure or the like, and a stable charge accumulation suppressing action can be obtained.

In this embodiment, the lower magnetic film is connected to the lead 15
Although the terminal is electrically connected to the terminal 10, the charge accumulation suppressing action can be obtained even when the terminal is connected to the terminal 9. That is, when a constant voltage of 10 V is biased to the coil 12, the upper magnetic film 13 and the lower magnetic film
A charge of ~ 3V is accumulated. On the other hand, since the magnetoresistive converter 8 has a resistance of about 20Ω and the sense current 18 is 10 to 15 mA, the potential difference between the terminals 9 and 10 is about 0.2 to 0.3V. Therefore, since the charge is about one digit smaller than the above-mentioned charge of 2-3V, there is no significant change in the charge accumulation suppressing action. However, if anything, the lead wire 15 is a readout IC2.
Is preferably connected to the terminal 10 on the GND terminal 4 side.

FIG. 4 is a schematic sectional view of a second embodiment of the thin-film magnetic head according to the present invention. FIG. 6 is a diagram showing a circuit in which the thin-film magnetic head and a read IC are connected. As shown in FIG.
4 to electrically connect the shield film 11 and the terminal 10. This embodiment is a thin-film magnetic head in which the coil 12 operates at a GND potential during reading instead of a constant voltage, and a charge is applied to the coil 12 at the time of writing.
1 to prevent charge from being accumulated. Therefore, the capacitance of the capacitor generated between the electrode 14 and the shield film 11 becomes substantially zero due to the lead line 19, so that no electric charge is stored in the capacitor and the pole portion 1
No electric charge is generated in the magnetic recording medium 03 and no electric discharge occurs from the pole section 103 to the magnetic recording medium 20 or the like. As for the connection of the lead wire 19, the electrical connection is completed inside similarly to the above-mentioned embodiment, and there is no room for the occurrence of a poor electrical connection or the like, and a stable charge accumulation suppressing action can be obtained. In this embodiment, even when the lead wire 19 is connected to the terminal 9, substantially the same effect can be obtained.

FIG. 5 is a schematic sectional view of a thin-film magnetic head according to a third embodiment of the present invention. FIG. 7 is a diagram showing a circuit in which this thin-film magnetic head and a read IC are connected. The electrodes 14, the shield films 7, 11 and the terminals 10 are electrically connected by the leads 15 and 19. Therefore, the capacitance of the capacitor generated between the coil 12 and the upper magnetic film 13, the electrode 14, and the shield films 7 and 11 becomes almost zero due to the lead lines 15 and 19. No charge is accumulated, no charge is generated in the pole portions 101, 102, 103, and no discharge from the pole portions 101, 102, 103 to the magnetic recording medium 20 or the like occurs.

The above-mentioned lead lines 15 and 19 are formed of a conductive thin film, and can be easily manufactured by a technique for producing a thin-film magnetic head such as ion milling using a photoresist mask.

Next, the magnetic disk drive of the present invention will be described. As schematically shown in FIG.
Are stacked at predetermined intervals in the axial direction of a spindle motor (not shown), and a thin film magnetic head is arranged corresponding to the recording surface. The thin film magnetic head is a rotary actuator (not shown)
Is positioned on the magnetic recording medium 20. Also,
These are controlled by the control device.

The thin-film magnetic head shown in each of the above-described embodiments is applied to this magnetic disk drive, and further, as shown in FIG. 1, the magnetic recording medium 20 is kept at the same potential as the GND 21 to further suppress discharge. be able to. As in the above-described embodiment, the electrical connection is completed inside, there is no room for electrical connection failure or the like, and a stable charge accumulation suppressing action can be obtained.

[0024]

As described above, according to the present invention, a discharge between a pole portion of a magnetic film or a shield film and a magnetic recording medium in which electric charge is stored in a capacitor is suppressed, and a thin film free from a read error due to the discharge is provided. The magnetic head can be realized inside the thin-film magnetic head without major changes in the magnetic disk drive and without significant improvement in the thin-film magnetic head. Further, this thin-film magnetic head can be easily assembled. The magnetic disk drive of the present invention is suitable for applying this thin-film magnetic head.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit in which a thin-film magnetic head according to a first embodiment of the present invention and a reading IC are connected.

FIG. 2 is a plan perspective view of a reading thin film magnetoresistive element of the thin film magnetic head according to the first embodiment of the present invention.

FIG. 3 is a schematic sectional view of a thin-film magnetic resistance element for reading and a thin-film magnetic conversion element for writing of the thin-film magnetic head according to the first embodiment of the present invention;

FIG. 4 is a schematic sectional view of a thin-film magnetic resistance element for reading and a thin-film magnetic conversion element for writing of a thin-film magnetic head according to a second embodiment of the present invention.

FIG. 5 is a schematic sectional view of a thin-film magnetic resistance element for reading and a thin-film magnetic conversion element for writing of a thin-film magnetic head according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a circuit in which a thin-film magnetic head and a reading IC according to a second embodiment of the present invention are connected.

FIG. 7 is a diagram showing a circuit in which a thin-film magnetic head according to a third embodiment of the present invention and a reading IC are connected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Thin-film magnetic head 2 ... Read-out IC 3 ... Transistor 4 ... GND terminal 5 ... Signal line 6 ... Thin-film magnetic conversion element 7, 11 ... Shield film 8 ... Magnetic resistance conversion part 9, 10 ... Terminal 12 ... Coil 13 ... Top Magnetic films 14, 16 ... Electrodes 15, 19 ... Lead wires 17 ... Thin film magnetoresistive element 18 ... Sense current 20 ... Magnetic recording medium 21 ... GND 101, 102, 103 ... Pole part 201 ... Gap film 202 ... Insulating films 203, 204 , 205, 206: protective film 301: magnetic recording medium facing surface

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Yoshiaki Karamaka 2880 Kozu, Kozuhara-shi, Kanagawa Prefecture, Ltd.Storage Systems Division, Hitachi, Ltd. Within the Storage Systems Division of the Works (72) Inventor Kiyonori Shiraki 2880 Kozu, Kodawara-shi, Kanagawa Prefecture Within the Storage Systems Division of Hitachi, Ltd. Within the department (72) Inventor Masaru Kagaya 2880 Kozu, Odawara City, Kanagawa Prefecture Inside Hitachi Computer Equipment Co., Ltd. (72) Noriaki Hatanaka 2880 Kozu, Kodawara City, Kanagawa Prefecture Hitachi, Ltd. Portion (72) inventor Tateo Mochizuki Kanagawa Prefecture, Totsuka-ku, Yokohama-shi Totsuka-cho, 180 Address Date start-communication system Co., Ltd.

Claims (4)

[Claims] 1. A writing thin-film magnetic conversion element having a coil, a magnetic film linked to the coil and constituting a magnetic circuit, two shield films, and a magnetoresistive converter sandwiched between the two shield films. A magnetic film of the thin-film magnetic transducer is electrically connected to one of terminals provided at both ends of the magneto-resistive transducer. Thin-film magnetic head. 2. A thin film magnetic transducer for writing having a coil, a magnetic film linked to the coil and constituting a magnetic circuit, two shield films and a magnetoresistive converter sandwiched between the two shield films. A thin film magnetic head comprising a read thin film magnetoresistive element having at least one shield film of said thin film magnetoresistive element electrically connected to one of terminals provided at both ends of said magnetoresistive conversion section. A thin film magnetic head characterized by the above-mentioned. 3. The thin-film magnetic head according to claim 1, wherein at least one shield film of said thin-film magnetic resistance element is electrically connected to said one terminal. 4. At least one magnetic recording medium, a thin-film magnetic head disposed opposite to the magnetic recording medium, for recording and reproducing information on and from the magnetic recording medium, and connected to the thin-film magnetic head. In a magnetic disk drive comprising: a readout integrated circuit; means for positioning the thin-film magnetic head at a desired position on the magnetic recording medium; and control means for controlling the thin-film magnetic head, the thin-film magnetic head is characterized in that: 3. The magnetic disk drive according to claim 3, wherein the one terminal is connected to a ground side of the readout integrated circuit.