JPS60115012A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent the generation of recesses and projections due to the partial wear of the driving surface of a recording medium, by forming a magnetic permeable film group containing a magneto-resistance effect element having an end counter to a magnetic recording medium and the other end connected magnetically to a magnetic permeable material on a nonmagnetic substrate having the magnetic permeable material buried. CONSTITUTION:A magnetic permeable material 16 is buried into a groove 17 formed to a nonmagnetic substrate 15, and a nonmagnetic insulated layer 18 is formed on an even surface of the substrate. Then a magnetic permeable film having a magneto-resistance effect is etched in a prescribed form to obtain an MR film 4b. Then an electrode 5 is formed in the same way, and a magnetic permeable film 14 is formed via a nonmagnetic insulated film 13. A nonmagnetic insulated film 19 is vapor-deposited on the film 14 with adhesion of a cover glass 20. Then a rubbing surface is polished to obtain a desired head. In such a constitution, a material having high wear resistance is available to a nonmagnetic substrate having a contact with a medium 11. This attains a thin film magnetic head which can work with high stability for a long period of time and with no eccentric wear.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thin film magnetic head suitable for reproducing perpendicular magnetization.

Conventional configurations and their problems It is known that perpendicular magnetic recording is inherently more suitable for high-density recording than conventional longitudinal magnetic recording.

However, there are still many problems in the regeneration process.
A thin film head considered to solve this problem will be described with reference to a perspective view in FIG. 1 and a sectional view in FIG. 2. A cutout groove 2 is provided at the end of a substrate 1 made of a magnetically permeable material such as NiZn ferrite, and a nonmagnetic material 3 is filled in the cutout groove 2 to form a new surface finished flush with the surface of the substrate 10. On top of that, for example, N i -Fe alloy r, 1
After forming a magnetoresistive film (hereinafter abbreviated as MR film) 4a by depositing it to a thickness similar to OA and etching it into a predetermined shape, a conductive electrode 6 made of Au or AI is attached to the MR film 4.
a magnetoresistive (MR) element 6
shall be. The upper end of the MR film 4a is the notch groove 2 of the magnetic substrate 1.
The MR film 4a is magnetically coupled to the upper end, and the lower end of the MR film 4a is in contact with the recording medium 11. Furthermore, about 10 μm of SiO
A non-magnetic film 7 such as the above is deposited as a protective film. A surface 12 of the magnetic substrate 1 that is substantially perpendicular to the MR element 6 is a surface that comes into contact with the recording medium 11, and arrow A is the direction of movement of the medium.

The thin film magnetic head configured as described above can achieve high performance characteristics by using a perpendicular two-layer recording medium in which a magnetically permeable film 9 is interposed between the base film 10 and the perpendicularly magnetized film 8 as the recording medium 11. .

That is, the magnetic flux generated from the signal magnetization recorded on the perpendicular recording medium 8 is guided to the lower end of the MR film 4a, passes through the MR film 4a, passes through the upper end of the MR film 4a, passes through the substrate 1, and contacts the contact surface 1 with the medium 11.
A closed magnetic path is constructed such that the magnetic flux is guided by the magnetic field 2, returns to the medium 11, returns to the lower end of the MR film 4a through the magnetically permeable film 9, and exhibits good reproduction characteristics.

Furthermore, if the perpendicular magnetization film 8 is a metal film such as Co--Cr, there is a problem of electrical leakage between the head (the structure in which the MR film 4a contacts the medium 11), as shown in FIG. It has also been considered to electrically insulate the MR film 4b from the medium 11 by providing a magnetically permeable film 14 for guiding magnetic flux via an insulating film 13 such as sio.

In either case, the length of the notch groove 20 in the medium movement direction must be several times or more the length in the perpendicular direction to prevent it from operating as a gap for the ring head, and the actual groove depth is 25 μm. The groove length is 2oOl1m. As the non-magnetic material in this groove, glass with a relatively low melting point, which is suitable for filling, has been used. When a recording medium runs on the head surface with such a configuration, the non-magnetic material 3 is greatly dented compared to the retention film 7 due to wear, resulting in a large space loss when reproducing short wavelength signals, which is a characteristic of perpendicular magnetic recording. It was not possible to fully utilize the high-density reproduction characteristics of the thin-film magnetic head.

On the other hand, it is conceivable to use a thin film forming method such as evaporation or sputtering to fill feed with a hardness greater than that of low melting point glass, but from the viewpoint of thin film processing for MR elements etc.
It is not realistic to fill a groove as deep as m by a thin film forming process.

OBJECTS OF THE INVENTION The present invention aims to provide a thin film magnetic head that prevents the occurrence of unevenness due to partial wear on the running surface of a recording medium and efficiently and stably reproduces short wavelength signal magnetization, which is a characteristic of perpendicular magnetic recording. purpose.

Structure of the Invention In order to achieve the above object, the present invention is characterized in that the head is formed by the following members.

1) A non-magnetic substrate with a magnetically permeable material embedded in the thin film formation surface.

2) A magnetically permeable film group including at least an MR element, one end facing the recording medium and the other end magnetically coupled to the magnetically permeable body.

According to the head of the present invention, since the medium sliding surface is made of a non-magnetic substrate and soft materials such as low-melting glass are not exposed, there is no uneven wear due to medium running, and good head characteristics are stably maintained for a long time. can. Furthermore, since sufficient magnetic flux flows between the magnetically permeable material embedded in the substrate and the recording medium for the reproduction operation, the magnetic properties are not affected.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. A non-magnetic substrate 15 such as crystallized glass has a diameter of 0.4 eye angle. W17 is formed, and a magnetically permeable material 16 such as Mn--Zn ferrite is embedded therein.

By polishing this surface, the surface of the Mn--Zn ferrite 16 and the surface of the non-magnetic substrate 160 are finished on the same plane. Next, a non-magnetic insulating layer 18 such as 8102 is formed by sputtering to a thickness of 0.6 μm, and then a magnetically permeable film having a magnetoresistive effect such as NiFe alloy is deposited to a thickness of 500 μm to form a predetermined shape. An MR film 4b is formed by etching. M.R.
The shape of the membrane 4 is, for example, a width of 20 pm and a length of 200 μm.
It overlaps with the magnetically permeable body 16 by about 5 μm. Thereafter, an electrode 6 made of Al is formed in the same manner, and a Ni-Fe alloy, Co-N
A magnetically permeable film 14, such as a b-Fe amorphous alloy, is formed. The width of the magnetically permeable film 14 is 16 μm, and the width of the magnetically permeable film 4 is 16 μm.
The overlap with that is 6 μm. Furthermore, a non-magnetic insulating film 19 such as SiO is deposited on this to a thickness of about 10 μm, and after adhering a cover glass 20, the moving surface of the tank is polished to form a head.

According to the above structure, a highly wear-resistant material can be used as the non-magnetic substrate that comes into contact with the medium 11, and uneven wear can be prevented. Furthermore, high-density perpendicular magnetization media having submicron wavelengths can be efficiently reproduced by the same operation as in the conventional example described above. That is, in the conventional example, one side of the magnetically permeable body was in contact with the recording medium, but even in a structure in which the recording medium 11 and the magnetically permeable body 16 are spaced parallel to each other as in this embodiment, the magnetic permeability is The magnetically permeable body 16 passes through the body 14 and the MR film 4b.
Most of the entered magnetic flux flows into the magnetically permeable film 9 through the magnetic gap formed by the non-magnetic substrate 15 before reaching the other end of the magnetically permeable body 16, so the length of the magnetically permeable body 16 is If selected appropriately, the reproduction operation will not be affected by the fact that the magnetically permeable body 16 is not in direct contact with the medium.

In this embodiment, the non-magnetic substrate 16 is made of photosensitive glass, but other materials suitable for the sliding surface of the magnetic head, such as 5102, sapphire, and glassy carbon, can be freely selected.

Another embodiment of the present invention will be described with reference to FIG. The non-magnetic substrate 16 of forsterite contains Ni-Zn.
A ferrite 16 is embedded, a groove 21 is formed in a part of the ferrite 16, a barium titanate layer 22 is formed by sputtering, and the surfaces thereof are polished so as to be on the same plane. The thickness of barium titanate is, for example, 20 μm. MR film 4a made of Ni-Fe alloy and A
An electrode 5 made of u/Cr is formed, and a cover 2 of forsterite is formed through a protective film 23 of barium titanate.
0 is joined. If the base of the MR film 4a is formed using a thin film as in this embodiment, the MR film 4 with good characteristics can be obtained even if a porous ceramic such as forsterite is used as the substrate 15. Ceramic can be used as the substrate material.

Effects of the Invention According to the present invention, the structure is such that a magnetic permeable material for magnetic flux conduction is embedded in a non-magnetic substrate, and the material of the head substrate can be selected regardless of the magnetic properties. If the head is made of a very hard material such as sapphire, or a material with low friction such as glassy carbon, it is possible to obtain a head with characteristics that suit the respective sliding characteristics.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional thin film magnetic head, FIG. 2 is a sectional view thereof, FIG. 3 is a sectional view of another conventional thin film magnetic head, and FIG. 4 is a first embodiment of the present invention. FIG. 5 is a cross-sectional view of a thin-film magnetic head according to a second embodiment of the present invention. 4b...MR film, 6...electrode, 15.
...Nonmagnetic substrate, 16...Magnetic permeable material. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure f Figure 3 Figure 4

Claims (2)

[Claims] (1) On one surface of a substrate made of a non-magnetic material in which a magnetically permeable material is embedded, one end is magnetically coupled to the magnetically permeable material near the boundary between the magnetically permeable material and the non-magnetic material, and the other end is 1. A thin film magnetic head comprising a magnetically permeable film group including a magnetoresistive element disposed at a position facing a recording medium. (2) A groove is formed at least at the position where the magnetoresistive element is to be formed on the surface of the substrate made of a non-magnetic material where the magnetically permeable material is embedded, and a thin film made of another non-magnetic film is formed. A thin film magnetic head according to claim 1, characterized in that: