JPS61122912A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To obtain a good recording density characteristic without unevenness up to a high density area by making a ridgeline of the end part of a ferromagnetic material in a recording media travelling surface non-parallel to an MR element of a thin film magnetic detecting part. CONSTITUTION:At a ferromagnetic material 1 of ferrite, etc., a notch groove 2 is formed from a thin film magnetic detecting part forming surface to a recording media travelling surface, and in it, a non-magnetic material 3 is charged. The notch groove 2 is made non-parallel for a magnetoresistance effect element (MR element) 4 of a thin film magnetic detecting part, and in such a case, formed elliptically. For this reason, the interference of a signal flux will not co-lectively occur at the special recording density, and the good recording density characteristic without unevenness up to a high density area can be obtained.

Description

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

2. Description of the Related Art As a magnetoresistive type perpendicular magnetization reproducing head, the present inventors have proposed, for example, a structure shown in Japanese Patent Application Laid-open No. 179927/1983. In other words, as the structure is shown in Figure 6,
It has a magnetic detection section made up of an MR element 4 and a ferromagnetic thin film 13, and a return core made of a ferromagnetic material 1. During a reproducing operation, the reproducing magnetic flux from the signal magnetization recorded on the perpendicular anisotropic film 8 is guided to the MR element 4 through the ferromagnetic thin film 13, and further passes through the ferromagnetic material 1f and flows into the recording medium 7. The signal passes through the ferromagnetic thin film 9 and returns to the original signal magnetization. At this time, a reproduction signal is obtained by utilizing the fact that the specific resistance of the MR element changes in accordance with the reproduction magnetic flux. still,
Even if the above-mentioned magnetic detection section is composed of a single MR element, its operation is the same.

(Japanese Unexamined Patent Publication No. 5A-1 Yes2A) Problems to be Solved by the Invention However, in the recording medium running surface of a head having such a structure, as shown in FIG. It is arranged 1,000 times the ridgeline of the detecting section (ferromagnetic thin M13 in this example), and furthermore, the distance between the ridgeline 11 and the magnetic detecting section is relatively short, and the edge of the ferromagnetic material on the surface where the magnetic detecting section is formed is located parallel to the recording section. If the distance is as straight as the distance to the medium facing part, when the magnetic flux generated from the signal magnetization of the recording medium passes through the MR element 4t, flows into the ferromagnetic material 1, and returns to the recording medium 7,
There is a problem in that unevenness occurs in the recording density characteristics because the magnetic flux is concentrated at the edge (edge line 11) of the ferromagnetic material 1 and interferes with the magnetic flux from the signal magnetization located below.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thin film magnetic head that eliminates the above-described irregularities in recording density characteristics and efficiently reproduces perpendicular magnetization up to a short wavelength region.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a thin-film magnetic detection section that forms a closed magnetic path by combining with a recording medium having a soft magnetic layer as described above.

At least the ridgeline of the area facing the thin film magnetic detection section is
It is configured to be non-parallel to the ridgeline of the thin film magnetic detection section.

According to the above-described configuration, the signal magnetization of the lower part of the ferromagnetic material end where the return magnetic flux concentrates differs depending on the position in the ridge line direction, so that the signal magnetic flux interferes intensively at a specific recording density. This is no longer the case, and unevenness in recording density characteristics is eliminated.

Embodiment Figure 1 shows an embodiment of the present invention, in which figure a is a perspective view, figure b is a plan view seen from the recording medium running surface, figure 0 is a side view seen from the surface on which the thin-film magnetic sensing portion is formed, and d. The figure is a sectional view of Moum' in figure a.

In the figure, reference numeral 1 is a ferromagnetic material such as ferrite, and a notched groove 2 is formed from the surface on which the thin film magnetic detection portion is formed to the recording medium running surface, and a non-magnetic material 3 such as glass is filled in the notched groove 2. . The shape of this notch groove on the recording medium running surface (
The ridgeline 11) is formed so as to be non-parallel to the ridgeline of the surface on which the thin-film magnetic detection portion is formed, and in the case of this embodiment, is formed in an elliptical shape as shown in FIG. Reference numeral 4 denotes a magnetoresistive (MR) element made of a ferromagnetic thin film, one end of which in the width direction is exposed to the recording medium running surface, and the other end is arranged so as to be magnetically coupled to the ferromagnetic material 1.

At both ends of the MR element 4 in the longitudinal direction, electrodes 6 for supplying current,
6 is formed. The recording medium 7 is a perpendicular two-layer medium in which a ferromagnetic thin film 9 such as permalloy and a perpendicular anisotropic film 8 such as Co-0r are formed on a paste 1o.

FIG. 2 shows an example of a head substrate having the above-mentioned notched grooves, in which a dicing saw or the like is used to extend the area from the thin film magnetic detection section forming surface of the ferrite block 1 to the recording medium running surface substantially perpendicular thereto. Form the notch groove 2 diagonally. that time.

The cross-sectional shape of the tip of the whetstone should be a circular arc or a suitable ellipse. After that, a non-magnetic material 3 such as glass is inserted into the notch groove 2.
f: Fill and form a smooth surface by grinding and polishing. FIG. 3 is an enlarged view of a part of the head substrate shown in FIG. 2, in which a film such as ML-F
・The alloy is deposited to a thickness of SOO by a vapor deposition method, and arranged so that one end in the width direction of the MR element 4 is magnetically coupled to the ferromagnetic material 1 using a photolithography technique, and then the MR element 4 is This figure shows a state in which a thin film magnetic detection section is formed in which electrodes 6, 6 are arranged at both ends in the longitudinal direction. Then, after placing the protective layer,
The front surface is polished to the position indicated by the dashed line BB'.

With this configuration, the magnetic flux generated from the signal magnetization recorded in the perpendicular anisotropic film 8 is guided from the lower end of the MR element 4, passes through the MR element 4, and passes through the ferromagnetic material 1 from its upper end. At the same time, a closed magnetic circuit structure is formed in which the signal flows into the ferromagnetic thin film 9 of the recording medium 7 and returns to the original signal magnetization. Because of this shape, the signal magnetization at the bottom of the ferromagnetic end where the return magnetic flux concentrates differs depending on the position in the ridge line direction, and the signal magnetic flux does not interfere with each other intensively at a specific recording density. Good recording density characteristics without unevenness can be obtained up to the high density area. Figure 4 shows the reproduction characteristics.

The horizontal axis shows the recording density, and the vertical axis shows the relative output.

Curve A shows the case where the ridge line 11 is parallel to the MR element 4, and it can be seen that a dip phenomenon occurs near the recording density corresponding to a bit length of an even number of the distance from the ridge line 11 to the MR element 4t. . The curved opening is the case of the present invention, and no dip phenomenon is observed up to the high-density region.

Note that the above effect can be achieved even if the ridgeline shape is non-parallel to the ridgeline of the magnetic detection part, but from the viewpoint of the manufacturing method, for example, in terms of grindstone management and mass production, the elliptical shape is Are suitable.

In addition, as shown in FIG. 6, the thin film magnetic detection section is M
Even if a ferromagnetic thin film 13 such as permalloy is disposed on the recording medium side of the R element 4 with an insulating layer 12 such as SiO□ interposed therebetween, the above-mentioned effect is exactly the same. In the case of such a structure, MR
Since the current flowing through the element 4 does not leak to the recording medium 7, restrictions on surface treatment of the recording medium or selection of materials are relaxed, and the range of applications is expanded.

Effects of the Invention As described above, the thin film magnetic head according to the present invention can reproduce perpendicular magnetization recorded at high density with high efficiency, and at the same time, it is possible to prevent interference of signal magnetic flux from occurring concentratedly at a specific recording density. Since there is no unevenness, it is possible to obtain good recording density characteristics without unevenness even in high-density areas. Furthermore, sufficient reproduction output can be obtained even if the relative speed between the head and the medium is small, and at the same time, this configuration is suitable for multi-tracking expected in the future.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a thin film magnetic head according to an embodiment of the present invention, FIG. 1 is a plan view seen from the recording medium side, and FIG. F
FIG. 2 is a perspective view of a head substrate according to an embodiment of the present invention, FIG. 3 is a partially enlarged view of FIG. 2, and FIG. 4 is a cross-sectional view of an embodiment of the present invention. FIG. 6 is a sectional view of a conventional thin film magnetic head, and FIG. 6 is a plan view of the conventional thin film magnetic head as viewed from the recording medium side. 1...Ferromagnetic material, 2...Notch groove, 3.
...Nonmagnetic material, 4...MR element, 5,6
······electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3
Figure 6

Claims (4)

[Claims] (1) A ferromagnetic material whose front surface serves as a recording medium running surface, a non-magnetic material filled in a notch provided from one side of the ferromagnetic material to the front surface, and a non-magnetic material that is adhered and formed on the non-magnetic material and whose one end is a thin film magnetic detection section that is magnetically coupled to a part of the side surface of the ferromagnetic material and whose other end faces the recording medium; A thin film magnetic head characterized in that an edge line of a region facing the thin film magnetic detection section is non-parallel to an edge line of the thin film magnetic detection section. (2) Claim 1, characterized in that the ridgeline of the end of the ferromagnetic material on the recording medium running surface has an elliptical shape.
The thin film magnetic head described in Section 1. (3) The thin-film magnetic head according to claim 1 or 2, wherein the thin-film magnetic detection section is constituted by a single thin-film magnetoresistive element made of a ferromagnetic material. (4) The thin film magnetic detection section is magnetically coupled to a thin film magnetoresistive element made of a ferromagnetic material and one end in the width direction of the thin film magnetoresistive element via an electrical insulator, and the other end 3. The thin-film magnetic head according to claim 1, wherein the thin-film magnetic head comprises a ferromagnetic thin film whose portion faces the recording medium.