JPS58115620A - Magnetic flux detection type magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic flux detection type magnetic head suitable to a sliding type magnetic head which has a less noise of sliding, good wear resistance, and superior reproduction characteristics by arranging a nonmagnetic material in such a way that a groove in the surface of ferrite constituting at least part of a magnetic circuit is filled, and providing a magnetic field detecting element on the embedded nonmagnetic material. CONSTITUTION:In the top surface of a ferrite substrate 40 with high magnetic permeability, a groove which is several-tens mum deep and tens-hundreds mum wide is made and in the groove, a nonmagnetic material is packed until the top surface of the embedded nonmagnetic material 45 is nearly equal in level to the top surface of said ferrite to obtain a composite substrate. On the substrate, an MR element 43 which is tens-hundreds nm thick is provided without overlapping with said ferrite groove at least one edge and on the surface of the ferrite where the MR element does not overlap, a magnetic material 42 with high magnetic permeability which is 1- tens mum thick is arranged with a nonmagnetic gap specifying film 41 between, thus coupling said high magnetic permeability material with the end of said MR element magnetically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic flux detection type magnetic head in which a magnetic field detection element is arranged in series with a part of a magnetic circuit configured to form a gap on a surface facing a magnetic recording medium.

Recently, research on magnetic heads using magnetoresistive elements (hereinafter abbreviated as MR elements in this specification) has been active as magnetic flux detection type magnetic heads.
In particular, in a magnetic head that is used by sliding on a magnetic recording medium, in a type in which a magnetoresistive element slides directly,
Disadvantages have been pointed out such as high sliding noise and difficulty in taking allowance for wear. As a method to eliminate this difficulty, as shown schematically in a cross-sectional view in FIG. It has been proposed to insert a high permeability magnetic material 3 between the surface facing the magnetic recording medium. However, in case B, in order to obtain sufficient resolution, it is necessary to make the thickness of the inserted high permeability magnetic material smaller than the wavelength of the recording signal, but on the other hand, in order to obtain sufficient sensitivity, it is necessary to There is a conflicting demand that the thickness must be increased, and it is difficult to satisfy the above characteristics at the same time. Another method for reducing sliding noise and securing wear allowance is to insert an MR element into a part of a magnetic circuit made up of high permeability magnetic materials facing each other via a gear drop on the surface facing the magnetic recording medium. It is proposed to do so. Specifically, as shown in FIG. 2, for example, a rear gap 21' is provided behind magnetic circuit forming bodies 22 and 22' made of a high permeability magnetic material such as ferrite, which face each other with a cap 21 interposed therebetween. MR in the rear gap
There is a plan to arrange the element 25. However, this proposal has the drawback that the magnetic path length of the magnetic circuit is long and leakage between opposing magnetic circuit formation bodies is also large, making it impossible to obtain sufficient regeneration efficiency. Another proposed method is to construct a magnetic circuit using a magnetic thin film and place an MR element in the middle of the magnetic circuit, as shown in FIG. In Figure 3, 30
is a non-magnetic substrate, 61 is a non-magnetic material for gap regulation, 3
232', 32' are high permeability magnetic thin films such as permalloy, and 33 is an MR element magnetically coupled to the high permeability magnetic thin films 32', 32''.

However, in such a head, it is difficult to maintain a sufficient distance between the 1MR element and the opposing magnetic circuit formation body, and in particular,
The thin film of the MR element itself usually needs to be much thinner than other magnetic circuit forming thin films, so the permeance is low (signal magnetic flux flowing into the MR element flows out halfway towards the opposing magnetic circuit forming body). In addition, since the direction of magnetization inside the MR element changes greatly in the height direction of the element, it becomes difficult to obtain linearity of the response to the signal magnetic flux. There is a drawback.

Therefore, an object of the present invention is to provide a magnetic flux detection type magnetic head suitable for a sliding type magnetic head, which has low sliding noise, high wear resistance, and excellent reproduction characteristics.

In order to achieve the above object, the magnetic flux detection type magnetic head according to the present invention of the type mentioned at the beginning has at least a part of the magnetic circuit made of ferrite, a groove is provided on the surface of the ferrite, and the groove is filled. .

The gist is that a non-magnetic material is completely arranged, and the magnetic field sensing element is provided on the embedded non-magnetic material directly or via another electrically insulating layer.

The present invention will be described in more detail below using examples while bathing the genitals, but it goes without saying that these are merely illustrative and that modifications may be made.

The magnetic head according to the present invention, as schematically shown in FIG. 4, has a groove 44 with a depth of several μm to several + μm 1 width + μm several tens to hundreds of μm on the upper surface of a high magnetic permeability ferrite substrate 40.
# Embed a non-magnetic material in the groove, and fill the embedded non-magnetic material 45
A layer of several tens of nanometers to several hundred nanometers in thickness is placed on a composite substrate whose upper surface is substantially flush with the upper surface of the ferrite so as not to overlap at least one of the edges of the groove of the ferrite.
m MR elements 46 are provided, and a high magnetic permeability magnetic material 42 with a thickness of 1 μm to several + μm is arranged on the surface of the ferrite on the side where the MR elements do not overlap, with a nonmagnetic gap regulating film 41 interposed therebetween. It has a structure in which the high permeability magnetic material is magnetically coupled to the end of the MR element. Also, if necessary,
The other end of the MR element is also provided with a high permeability magnetic material 42' for magnetically coupling with the other side of the ferrite groove.

In a magnetic head with such a structure, since the magnetic circuit forming body facing the 1MR element can be placed sufficiently far away, it is possible to prevent the MI (outflow of the signal magnetic flux from the middle of the element) as described above, and to prevent the signal magnetic flux from flowing out from the middle of the element. It is possible to ensure sufficient linearity of the response to A magnetic flux detection type magnetic head suitable for a dynamic magnetic head can be obtained.

Although the above example shows a structure in which the MR element is directly provided on the composite substrate, as shown in FIG. 53 may also be provided.

In particular, when the ferrite 50 is made of Mn, -Zn ferrite, it is necessary to prevent the MR element from being electrically connected to the ferrite. As described above, when the gap regulating film is used to serve as electrical insulation between the MR element and the substrate, the high magnetic permeability magnetic thin film 52, 52' which is a magnetic circuit forming body magnetically coupled to the MR element is When it is a good electrical conductor, the MR element is covered with an insulating film 51'.
It needs to be covered with.

Further, although not shown in the above example, a conducting wire for applying a bias magnetic field, a permanent magnet film, or the like may be arranged in close proximity to the MR element.

As explained above, according to the present invention, the magnetic flux detection type is suitable for a sliding magnetic head that has low sliding noise, high wear resistance, and excellent reproduction characteristics.

A magnetic head can be obtained.

[Brief explanation of drawings]

FIG. 1 shows -s of a conventional magnetically shielded MR head. A schematic side view showing an example, FIG. 2, has a gap. FIG. 3 is a side view showing an example of a conventional magnetic head in which an MFL element is arranged as a part of a magnetic circuit. FIGS. 4 and 4 are cross-sectional views showing other examples of a conventional magnetic head in which an MR element is arranged in a part of a magnetic circuit. FIG. 5 is a sectional view of a magnetic head according to two different embodiments of the present invention. 1.23,55,4! l, 53... magnetoresistive element, 2. . 2'...Magnetic shield, 22.22', 52.
52', 52', 42. . 42', 52.52'... High permeability magnetic thin film, 21
．． 21'...呵. Gap, 31.41.51... Gap regulation film,
4o. 50... Ferrite substrate, 44.54... Groove provided in ferrite substrate, 45.55... Embedded non-magnetic material, 51'... Insulating film. Representative patent attorney Junnosuke Nakamura 11 figures 3 figures 2 f31 1'4 figures f5 figures

Claims (1)

[Claims] In a magnetic head in which a magnetic field sensing element is arranged in series with a part of a magnetic circuit configured to form a gap on the surface facing the magnetic recording medium, at least a part of the magnetic circuit is made of ferrite, and grooves are formed on the surface of the ferrite. , a nonmagnetic material is arranged to fill the groove, and the magnetic field detection element is provided on the embedded nonmagnetic material directly or through another electrically insulating layer. .