JPS6052907A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the efficiency of reproduction and at the same time to prevent an external noise magnetic field by providing a thin film of high permeability formed as prescribed at a place near a magnetized layer of a recording medium, a block of high permeability, a main magnetic pole made of a nonmagnetic substance, a substance of high permeability set close to the main magnetic pole and another substance of high permeability set at the opposite side to the main magnetic pole. CONSTITUTION:A thin film 4 of high permeability is formed close to a magnetic recording medium 3 consisting of a magnetized layer 1 and a layer 2 of high permeability, and a block 10 of high permeability is formed following to a part of the film 4. A main magnetic pole 6 contains a tip part 17 where the film 4 is anclosed by a nonmagnetic substance 5 at the area close to the medium 3. A block 10 of high permeability is provided close to the pole 6, and a block 12 of high permeability is provided at the opposite side to the pole 6. A coil 7 is wound around the pole 6. Both blocks 10 and 11 are set close to the pole 6. In this way, the magnetic resistance of the film 4 is reduced, thus improving the efficiency of reproduction and reducing the effect of external noises.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head that performs recording or reproduction in a direction perpendicular to a recording medium.

Conventional Structures and Problems The perpendicular magnetization recording method has been proposed as a method for performing high-density magnetic recording (see, for example, Japanese Patent Laid-Open No. 62-134706 and Japanese Patent Laid-Open No. 63-3209). This method has the feature that the demagnetizing field of recorded magnetization is small and allows high-density magnetic recording, but it requires a recording medium with perpendicular anisotropy and a perpendicular magnetic recording head with a strong magnetic field in the perpendicular direction. shall be. FIG. 1 shows an example of a conventionally proposed perpendicular magnetic recording head. A magnetic recording medium 3 has a medium high permeability layer 2 under the magnetic layer 1 having a perpendicular magnetic anisotropy f1. A magnetic pole 6 is provided, and a coil 7 is wound around the main magnetic pole 6 to perform perpendicular magnetic recording or reproduction as electrical input or output.

In the conventional head having a tree structure, the recording medium is formed by magnetic flux passing through a magnetic circuit 8 formed by a current flowing through a coil 7, and the magnetic layer 1 is
A portion close to the high magnetic permeability thin film 4 is magnetized and recorded.

Conversely, during reproduction, the magnetic flux due to the magnetization of the portion of the magnetic layer 1 adjacent to the high permeability thin film 4Vc flows through the magnetic circuit 8,
By interlinking the coil 7, the coil 7 outputs an electric signal. Here, the conventional magnetic head has a magnetic circuit 8
Because of its high magnetic resistance, it had the disadvantage of poor efficiency both during recording and reproduction. There are three reasons why the magnetic resistance increases. The first is that the high magnetic permeability thin film 4 is generally 1.
This is because although it is thin at about 1 m, it is several mm long, so even if it is made of a high magnetic permeability material such as permalloy, the magnetic resistance will be large. The second cause is the high magnetic permeability thin film 4.
Since the magnetic circuit 8 is formed in the medium high magnetic permeability layer 2 through air having a low magnetic permeability, the magnetic resistance becomes large. Furthermore, the third cause is that the thickness of the medium high magnetic permeability layer 2 is 1 μm or less and the length of the portion that becomes a part of the magnetic circuit 8 is as large as several n, which increases the magnetic resistance.

As described above, the conventional perpendicular magnetic recording head has a drawback of high magnetic resistance, resulting in poor recording or reproducing efficiency.

Furthermore, the conventional example described above has the disadvantage that it is susceptible to the influence of external magnetic fields. This situation is shown in FIG. 2, in which the same parts as in FIG. 1 are designated by the same numbers.

The unnecessary noise magnetic field from the outside passes through the magnetic circuit 9, interlinks the coil 7, and becomes electrical signal noise from the coil 7 as external noise. This is considered to be because the high magnetic permeability thin film 4 serves as an antenna for external noise magnetic fields.

In this way, magnetic heads with conventional configurations have low recording and reproducing efficiency.
It had a drawback in terms of the influence of external magnetic fields.

OBJECTS OF THE INVENTION The present invention eliminates all of the above-mentioned conventional drawbacks, and aims to provide a magnetic head that greatly improves recording or reproducing efficiency and eliminates the drawback of being susceptible to external noise magnetic fields. be.

Structure of the Invention The present invention achieves the above object by providing a high permeability magnetic thin film in close proximity to a magnetic recording medium having a high permeability layer under a magnetization layer having perpendicular magnetic anisotropy. A main magnetic pole having a structure in which a portion of a magnetic thin film close to the magnetization layer is sandwiched by at least a non-magnetic material, and has at least a first high magnetic permeability material magnetically connected to the high permeability magnetic thin film. , a second high magnetic permeability body provided close to or connected to the main magnetic pole, and a third high magnetic permeability body provided on the opposite side of the main magnetic pole with the magnetic recording medium in between. It provides a magnetic head with all the features.

Description of examples Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a sectional view of a magnetic head according to an embodiment of the present invention, and the same parts as in FIG. 1 are designated by the same numbers.

In this embodiment, a high magnetic permeability thin film 4 is provided adjacent to a magnetic recording medium 3 consisting of a magnetization layer 1 and a medium high magnetic permeability layer 2, and a first high magnetic permeability block 1o is provided connected to a part of the thin film 4. , a portion of the high magnetic permeability thin film 4 near the magnetic recording medium 3 is covered with a non-magnetic material 6.
A main magnetic pole 6 including a tip portion 17 sandwiched between the main poles 6 and 6 is provided. A second high magnetic permeability block 11 is provided close to the main magnetic pole 6 on the main magnetic pole 6 side of the magnetic recording medium 3 . Further, a third high magnetic permeability block 12 is provided on the opposite side of the main magnetic pole 6 of the magnetic recording medium 3. A coil 7 is wound around the main pole 6.

The effects of this embodiment with such a configuration will be described. By providing the first high magnetic permeability block 10 magnetically connected to the high magnetic permeability thin film 4, the magnetic resistance of the high magnetic permeability thin film 4 can be significantly reduced.

By providing the twisted second high magnetic permeability block 11 close to or connected to the main magnetic pole 6 on the main magnetic pole 6 side of the magnetic recording medium 3, a magnetic circuit 13 is formed, and the magnetic circuit 13 passes through the air. We were able to significantly reduce magnetic resistance without any problems. Furthermore, by providing the third high magnetic permeability block 12 on the opposite side of the main magnetic pole 6 of the magnetic recording medium 3, the short distance 11 of the magnetic circuit 13 passing through the medium high magnetic permeability layer 2 can be shortened, and the medium height can be reduced. The effect of significantly reducing the magnetic resistance of the magnetic permeability layer 2 was obtained.

The second high magnetic permeability block 11 is formed on at least one side of the main magnetic pole 6 (C is sufficient, and the non-magnetic material 6 is sandwiched between the tip portion of the high permeability thin film 4 near the magnetic recording medium 3). Any structure is fine.

The above-described combination of structures for reducing the magnetic resistance at three locations makes it possible to significantly reduce the overall magnetic resistance, and the efficiency of the head is greatly improved in both recording and reproduction. Specifically, the high magnetic permeability thin film 4 is made of CO, which has higher saturation magnetization and higher magnetic permeability than permalloy, which is commonly used conventionally.
and Zn (amorphous material whose main component is i7, e.g. C
The first high magnetic permeability block 10 is formed of an amorphous material such as oZrNb or CoFeZrNb, and the length of the main pole tip portion 17 is approximately 5100 μm.The first high permeability block 10 is formed of a ferrite material, etc.
The thickness is 100 μm and the length is about 6 mm. The second high magnetic permeability block 11 is made of a ferrite material or the like, and is configured to be sufficiently larger than the first high magnetic permeability block 10 to reduce the magnetic resistance of the space. Third high permeability block 1 on the back side of the medium
2 also has a large surface facing the second high magnetic permeability block 11 to completely reduce magnetic resistance, and uses ferrite material or the like.

FIG. 4 is an explanatory diagram showing that the configuration of this embodiment is less affected by external noise magnetic fields; the noise magnetic field from the outside mainly passes through the magnetic circuit 14, which has a relatively large path, and the magnetic circuit 14, which has a relatively small path. Since the amount passing through the circuits 16 and 16'i is small, the amount by which the external noise magnetic field interlinks with the coil 7 is reduced as a whole, and the influence of external noise is significantly reduced.

FIG. 6 is an explanatory diagram for optimizing the above embodiment, and is a partially enlarged view of the main pole tip 17 in FIG. 3.

A magnetic circuit 19 in which magnetism passes through the third high magnetic permeability block compared to a magnetic circuit 18 in which magnetism passes through the medium high magnetic permeability layer 2.
In order to further reduce the magnetic reluctance of It needs to be bigger.

Furthermore, as shown in FIG. 6, in this embodiment, in order for the magnetic flux from the medium to sufficiently interlink with the coil 7 during reproduction, the magnetic circuit 20 that interlinks the coil 7 is replaced by a magnetic circuit 21 that does not interlink the coil 7. It is desirable that the magnetic resistance be lower. For this purpose, the magnetic resistance between the first high magnetic permeability block 1o and the medium high magnetic permeability layer 2 must be greater than the magnetic resistance between the second high magnetic permeability block 11 and the third high magnetic permeability block 12. The condition is that it is large. Since magnetic resistance is proportional to the distance of the magnetic path and inversely proportional to the area, the area of the first high magnetic permeability block 1o facing the medium high magnetic permeability layer 2 is assumed to be 'ji7sd, the average distance is d, and the second high magnetic resistance is If the area of the facing portion of the magnetic permeability block 11 and the third high magnetic permeability block 12 is Su, and the average distance is U, then the above condition is satisfied by setting d/5d)u/Su.

Similarly, the magnetic resistance between the first high magnetic permeability block 10 and the medium high magnetic permeability layer 2 is greater than the magnetic resistance between the first high magnetic permeability block 1Q and the second high magnetic permeability block 11. Being large is also a condition. For this, d/Sd>v/S
It is necessary to set it to v. Here, the area of the opposing portions of the first high magnetic permeability block 10 and the second high magnetic permeability block 11 is Sv, and the average distance is V.

Furthermore, in this embodiment, in order to reduce the influence of external noise magnetic fields, it is desirable that the magnetic resistance of the magnetic path 16 in FIG. , in this case, the magnetic resistance between the first high magnetic permeability block 1o and the second high magnetic permeability block 110 is the same as the magnetic resistance between the second high magnetic permeability block 11 and the third high magnetic permeability block 12. It is desirable that the resistance be greater than that.

Therefore, the first high permeability block 1o is the medium high permeability layer 2.
There is a distance d between the area Sd of the facing portion and its average distance d, and the area Sv and the average distance V of the opposing portions of the first high magnetic permeability block 10 and the second high magnetic permeability block 11.
It is desirable to configure it so that the relationship /Sd>V/Sv is satisfied.

Effects of the Invention In short, the present invention provides a high permeability magnetic thin film in close proximity to a magnetic recording medium having a high magnetic permeability layer below a magnetization layer having perpendicular magnetic anisotropy. a main magnetic pole having a structure in which a portion adjacent to the magnetization layer is sandwiched by at least a non-magnetic material and has at least a first high magnetic permeability material magnetically connected to the high magnetic permeability magnetic thin film; A second cylindrical magnetic permeability body provided adjacently or connected to each other, and a third high magnetic permeability body provided on the opposite side of the main magnetic pole with the magnetic recording medium sandwiched therebetween. The present invention provides a magnetic head characterized in that it has the advantage of lowering the resistance of the magnetic circuit of the magnetic head, increasing recording or reproducing efficiency, and reducing the influence of external noise magnetic fields.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional perpendicular magnetic recording head, FIG. 2 is a sectional view of a conventional perpendicular magnetic recording head showing the influence of an external noise magnetic field, and FIG. 3 is a magnetic head according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of the magnetic head according to this embodiment showing the influence of an external noise magnetic field, and FIGS. 5 to 7 are partially enlarged views showing the optimal structure of this embodiment. DESCRIPTION OF SYMBOLS 1...Magnetic layer, 2...Medium high permeability layer, 3...Magnetic recording medium, 4...High magnetic permeability thin film, 6... ...Non-magnetic material, 6...Main magnetic pole,
7... Coil, 8,9°14.15,16.1
B, 19, 20.21...0. . Magnetic circuit, 10...First high magnetic permeability block, 1
1...Second high permeability block, 12. Mountain...
Third high permeability block, 17...main magnetic pole tip portion. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Fig. 4 - Figure 3 Figure 1/2 Figure 4: ', 171 Figure 5 2 41- Figure 7 1

Claims (1)

[Scope of Claims] (1) A high permeability magnetic thin film is provided in close proximity to a magnetic recording medium having a high permeability layer under a magnetization layer having perpendicular magnetic anisotropy, and the high permeability magnetic thin film is a main magnetic pole having a structure in which a portion adjacent to the magnetization layer is sandwiched by at least a non-magnetic material and has at least a first high magnetic permeability material magnetically connected to the high magnetic flux magnetic thin film; A second high magnetic permeability body provided close to or connected to each other, and a third high magnetic permeability body provided on the opposite side of the main magnetic pole with the magnetic recording medium sandwiched therebetween. magnetic head. (2) The distance e between the high magnetic permeability magnetic thin film and the second high magnetic permeability body in the part where the main magnetic pole is close to the magnetic layer is the distance e between the high magnetic permeability layer and the third high magnetic permeability body. A magnetic head according to claim 1, characterized in that the distance is greater than the distance t. (3) The area isd of the opposing portion of the first high magnetic permeability body and the high magnetic permeability layer, d is the average distance between the first high magnetic permeability body and the high magnetic permeability layer, and the second and third high magnetic permeability The area of the opposing parts of the body is Su, the average distance between the second and third high magnetic permeability bodies is U, the area of the opposing parts of the first and second high magnetic permeability bodies is Sv, and the first and second high permeability bodies are Sv. When the average distance between two high permeability materials is V, d
2. The magnetic head according to claim 1, wherein the magnetic head is configured such that 15d>u/Su and d/Sd>v/Sv. (4) The area of the opposing parts of the second and third high magnetic permeability bodies is Su, the average distance between the second and third high magnetic permeability bodies is U, and the first
The area of the opposing portion of the second high magnetic permeability body is Sv, and the area of the first
The magnetic heside according to claim 1, characterized in that, when the average distance between the second high magnetic permeability body and the second high magnetic permeability body is V, v/Sv)u/Su. (6) The magnetic head according to claim 1, wherein the high permeability magnetic thin film is made of an amorphous material containing Co and Zr as main components. (6) High permeability magnetic thin film made of Go, Fe, Zr
7. The magnetic head according to claim 6, wherein the magnetic head is made of an amorphous material containing Nb.