JPH0991631A - Magnetoresisive magnetic head and composite magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of reproducing sensitivity of an MR head caused by a lead terminal part of an MR magneto-sensitive part exposed on a medium slide surface of a vertical MR head. SOLUTION: The low potential side lead of the MR head exposed on the medium slide surface 6 formed on the same surface as an MR magneto-sensitive part 4 forming surface is formed by a non-magnetic conductive thin film 7 formed on the medium slide surface 6. Then, the lead is connected electrically to the magnetic shields 2 and 9 of the MR magneto-sensitive part 4, and is used also as the lead terminal of the MR head. Thus, since the MR magneto- sensitive part is made nearer to the medium slide surface, the sufficient sensitivity is obtained. Further, since the shield is used also as the lead of the MR head, the necessity that the lead is formed is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive head of a magnetic head for high density recording (hereinafter referred to as MR head).
Regarding

[0002]

2. Description of the Related Art As the density of magnetic recording has increased, the gap and track of magnetic heads have become narrower, and reproduction with inductive heads has become insufficient in output, and replacement with MR heads having high reproduction sensitivity has progressed. At the same time, a composite head such as a thin film inductive head as a recording head and an MR head as a reproducing head is being replaced. However, even if the head used for reproduction is an MR head, the magnetoresistive effect magnetic sensing unit (hereinafter referred to as M
When the distance between the R magnetic sensitive portion) and the medium sliding surface is large, there is a problem that the sensitivity becomes insufficient. When using an MR head of the type that exposes the MR magnetic sensitive portion to the medium sliding surface. Was common. However, for example, a hard disk
When used as a reproducing head of a drive, and when the MR head is exposed to the medium sliding surface, the surface potential of the surface of the hard disk rises due to airflow during rotation, static electricity is accumulated, and the magnetic head If it approaches or contacts the hard disk at the time of starting or stopping the operation, a discharge is generated between the end of the MR sensitive section exposed on the medium sliding surface and the lead, depending on the direction of the current flowing through the MR sensitive section. M
There is also a problem that the R magnetic sensitive section is destroyed.

As shown in FIG. 6, a vertical MR head or a composite magnetic head with the vertical MR head has an MR magnetic sensitive section 40 on a core 20 of a thin film inductive head deposited on a substrate 19 via an insulating layer 30. It is formed at a position apart from the medium sliding surface 55 extending in a direction substantially orthogonal to the medium sliding surface 55. However, the MR is moved in a direction substantially orthogonal to the medium sliding surface 55.
Since the current is passed, a depth corresponding to the width L1 of the lead terminal 50 laminated on the MR magnetic sensing part 40 is generated, and the reduction of the reproduction sensitivity cannot be avoided. In the future, the track width (T in the figure shows half of that) tends to become narrower for higher density, and it is essential to increase the reproduction sensitivity.

[0004]

Therefore, the present invention has been proposed in view of the above situation, and it is a highly reliable MR magnetic device that solves the lack of sensitivity of the MR head and avoids electrostatic breakdown. A head and a composite magnetic head are provided.

[0005]

In order to achieve the above object, the present invention provides a non-magnetic conductive thin film in which a low potential side lead of an MR magnetic sensing portion of a vertical MR head is formed on a medium sliding surface. To provide the MR head. Further, the low-potential-side lead of the MR sensitive section of the vertical MR head having the magnetic shield made of a conductive material is electrically connected to the magnetic shield on the medium sliding surface, and the magnetic shield is connected to the lead of the MR sensitive section. An MR head that also serves as the above is provided. A composite magnetic head in which a thin film inductive magnetic head is formed directly on an MR head, and the magnetic core of the thin film inductive magnetic head in which the low potential side lead is exposed on a medium sliding surface is electrically connected to the magnetic core. To provide a composite magnetic head in which the magnetic core is also used as a lead of the MR magnetic sensing section.
Also provided is an MR head or a composite type magnetic head in which the low potential side lead formed on the medium sliding surface is covered with a wear resistant thin film.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the MR head of the present invention will be described with reference to FIG. The MR head shown in FIG. 1 is an example of a magnetic head for HDD, and a magnetic thin film made of permalloy, sendust, or FeTaN alloy is applied as a shield 2 of the MR head to a non-magnetic substrate 1 made of alumina, Altic, or the like. The MR magnetic sensing portion 4 is arranged at a position closest to the medium sliding surface 6 via the first insulating layer 3 such as SiO2 or SiO2, and the lead 5 is provided at the other end portion at one end portion of the MR magnetic sensing portion. The non-magnetic conductive thin film 7 attached to the medium sliding surface 6 is connected to the MR magnetic sensing part 4 so that the MR current flows from one end lead of the MR magnetic sensing part 4 to the other end lead, that is, a low potential. It is designed to flow in the direction of the side lead. Although the MR magnetic sensing part 4 is located in the immediate vicinity of the sliding surface 6 of the medium, a non-magnetic conductive thin film 7 is deposited on the surface of the MR magnetic sensing part 4 very thinly from 100 angstrom to 0.1 micron. The sliding surface 6 is not directly exposed. Therefore, the reproduction sensitivity is sufficiently high, and since it is covered with the conductive thin film 7, it is not damaged by discharge. FIG. 2 is a plan view seen from the medium sliding surface of the MR head. In the case of the composite magnetic head according to claim 3, as shown in FIG. 3, the first magnetic core 9 of the thin film inductive magnetic head is interposed via the second insulating film 8 of the MR head having the configuration of FIG. This is a structure in which the coil 11, the insulating film 12 serving as a gap, and the second magnetic core 13 are formed, and the protective layer 14 and the like are laminated. Although a non-magnetic material is used for the substrate in this embodiment, a magnetic material such as ferrite may be used. In that case, there is an advantage that an effect as a shield material can be expected.

A method of manufacturing a magnetic shield MR magnetic head made of a conductive material will be described. As shown in FIG. 4, first, a magnetic thin film such as permalloy which becomes the lower shield 2 of the MR magnetic sensitive portion by sputtering is formed on an alumina substrate 1. Deposition (a),
The MR magnetic sensing section 4 via the first insulating layer 3 made of alumina.
Then, the leads 5 are attached and patterned at predetermined positions.
However, this MR magnetic sensitive portion may be a giant MR (hereinafter referred to as GMR) magnetic sensitive portion (b). Next, the second insulating layer 8 is again deposited thereon with alumina or the like, the upper shield 9 of the MR magnetic sensing portion is deposited thereon, the protective layer 14 is formed (c), and the step of FIG. d) The medium sliding surface is formed by the one-dot chain line portion (d), and the non-magnetic conductive thin film 7 is adhered to the medium sliding surface 6 to electrically connect the MR magnetic sensing section 4 and the upper and lower shields 2 and 9. After connection, the abrasion resistant thin film 15 is applied to complete the MR head (e). The composite magnetic head according to claim 3 is manufactured as shown in FIG. The process is performed on the magnetic shield 9 and the second insulating layer 8 of the MR head manufactured through the above-described MR head manufacturing processes (a), (b), and (c), and a third insulating material such as alumina. The layer 10 is deposited by sputtering or the like, and then aluminum or copper is deposited and patterned to form a thin film coil 11 thereon (d). Upper shield 9
Is also the first magnetic core of the thin film inductive head in the composite magnetic head. Next, a magnetic gap 1 with a non-magnetic thin film
2 is formed and permalloy is further applied by plating or sputtering to form the second magnetic core 13 of the thin film inductive head. A lead is drawn out from aluminum, copper, gold or the like to form an electrode (not shown), a protective film 14 such as alumina or SiO 2 is attached, and the film forming process is completed. Next, substrate 1
The formed MR head is cut into bars arranged in a horizontal line, and then polished from the side that becomes the medium sliding surface to a predetermined dimension of the one-dot chain line in FIG. 5 (e) to form the medium sliding surface 6. To do. Next, a non-magnetic conductive thin film 7 such as aluminum, copper, or gold is deposited on the medium sliding surface 6 by sputtering or the like, and patterned to connect the MR magnetic sensing section 4 and the upper and lower shields 2 and 9. In this case, it is not necessary to newly form the leads by using the upper and lower shields 2 and 9 as one of the lead terminals of the MR head, thus reducing the number of steps. Further, graphite is sputtered and diamond-like wear resistant coating 15 is deposited to complete the magnetic head (f).

[0008]

EXAMPLE When a GMR element is adopted, a spin valve film consisting of three layers of an alloy layer of permalloy and tantalum, an alloy layer of permalloy and rhodium, and an alloy layer of permalloy and chromium is used. 2 film and non-magnetic metal film
A good magnetic head was obtained even with a GMR film made of a laminated film of more than one layer. Further, in the vertical MR head of the present invention, the MR
Since the magnetically sensitive portion 4 was ground until it was exposed on the medium sliding surface 6, and a nonmagnetic conductive thin film was applied to the medium sliding surface to form a lead, there was a sufficient margin for the sensitivity of the MR head. Furthermore, the spin valve film needs to apply a bias magnetic field at a constant angle with respect to the signal magnetic field incident direction, but in the case of a vertical MR head structure, this bias magnetic field can be generated only by the current flowing in the MR magnetic sensing section. Since it is not necessary to separately provide a magnetic field generating means such as a permanent magnet, manufacturing becomes extremely easy and reliability is improved. Further, the method of sputtering graphite into diamond is attempted to improve the wear resistance of the head that slides on the medium and is effective in the wear resistance, but due to the spacing loss due to the film thickness. There was a problem that the sensitivity was lowered, and it was not practical. However, in the HDD head, since the head is floating, there is no problem of spacing loss due to the diamond layer, and there is a remarkable effect in improving the abradability by sliding with the medium when the magnetic head starts or stops operating.

[0009]

Since the MR magnetic sensing section can be brought close to the medium sliding surface, sufficient sensitivity can be obtained. Also, M
Since the conductive thin film is applied to the lead without sticking the R magnetic sensitive part to the sliding surface of the medium, the MR magnetic sensitive part is not destroyed even if the medium is discharged. Further, since the shield of the MR head is shared with the leads, it is not necessary to form the leads.
Further, the abrasion resistance of the conductive thin film adhered to the sliding surface of the medium ensures the abrasion resistance of the conductive thin film when the magnetic head starts and stops its operation.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an MR head of the present invention.

FIG. 2 is a front view of the MR head of the present invention.

FIG. 3 is a sectional view of a composite magnetic head of the present invention.

FIG. 4 is a manufacturing process diagram of the MR head of the present invention.

FIG. 5 is a manufacturing process diagram of the composite magnetic head of the present invention.

FIG. 6 is a perspective view of a conventional composite magnetic head including a vertical MR head and a thin film inductive head.

[Explanation of symbols]

 3 First Insulating Layer 4 Magneto-Resistance Effect Magnetic Sensitive Area 6 Media Sliding Surface 7 Non-Magnetic Conductive Thin Film (Low-potential-side Lead) 8 Second Insulating Layer 9 Magnetic Shield 15 Abrasion Resistant Thin Film

Claims (4)

[Claims] 1. A magnetoresistive effect magnetic head in which a low-potential-side lead of a magnetoresistive effect magnetic sensing part is a nonmagnetic conductive thin film formed on a sliding surface of a medium in a vertical magnetoresistive effect magnetic head. head. 2. A low potential side lead of a magnetoresistive sensing section of a vertical magnetoresistive effect type magnetic head having a magnetic shield made of a conductive material is electrically connected to the magnetic shield on a medium sliding surface, A magnetoresistive effect type magnetic head characterized in that the shield is also used as a lead of a magnetoresistive effect magnetic sensitive section. 3. A composite magnetic head in which a thin film inductive magnetic head is directly formed on the magnetoresistive magnetic head according to claim 1, wherein the low potential side lead is exposed on a medium sliding surface. A composite magnetic head, which is electrically connected to a magnetic core of the thin film inductive magnetic head, and which is also used as a lead of a magnetoresistive effect magnetic sensitive section. 4. The low potential side lead formed on the medium sliding surface is covered with a wear resistant thin film.
2. The magnetoresistive magnetic head or the composite magnetic head as described in 2 or 3.