JPS6132722B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head and a method of manufacturing the same.

[Conventional technology]

The electromagnetic conversion efficiency (head efficiency) and other characteristics of a thin film magnetic head are related not only to the magnetic properties of the magnetic material forming the magnetic core, but also to its structure. With respect to head efficiency, if other conditions are equal, the thicker the magnetic core material, the higher the head efficiency.

Similarly, in order to increase the recording density, it is desirable that the thickness of the portion of the magnetic core material facing the recording medium, that is, the magnetic pole portion, be as thin as possible.

In addition, when considering writing using a thin film magnetic head, the magnetic core material has saturation magnetic flux B _s and magnetic permeability μ
However, if the magnetic reluctance of the magnetic core is uniform throughout the core, the magnetic flux is limited to saturation at a location away from the magnetic pole part of the core, and the number of saturated magnetic fluxes increases. Since only one-half of the magnetic flux is effectively used for magnetic recording, the conventional structure had the disadvantage that it was not possible to generate a large recording magnetic field while using a material with a large saturation magnetic flux.

[Problem that the invention seeks to solve]

In order to obtain a thin film magnetic head with good characteristics, it is necessary to overcome the above contradictory conditions and eliminate the above drawbacks.

The object of the present invention is to solve the difficulty of overcoming the above-mentioned contradictory conditions, and to provide a thin-film magnetic head with good characteristics that eliminates the above-mentioned drawbacks.

[Means for solving problems]

According to the present invention, this purpose consists of a main magnetic core made of a thin film, a part of which constitutes a magnetic pole, and an auxiliary magnetic core made of a thin film provided on the outside of the main magnetic core except for the magnetic pole part. One of the auxiliary cores is reached by a thin film magnetic head consisting of a magnetic thin film provided inside a groove formed in the substrate.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a thin film magnetic head embodying the present invention taken along a plane perpendicular to the magnetic pole surface.
In the figure, a shallow groove 2 is first formed on the surface of a substrate 1 holding the head, and a magnetic thin film 3 is formed in the groove. This thin film constitutes an auxiliary magnetic core as described below. The thickness of the thin film 3 is such that its surface coincides with the surface 4 of the substrate 1. Furthermore, as shown in the figure, a magnetic thin film 5 having a size equal to the width of the magnetic pole of the head is applied from a portion slightly closer to the magnetic pole surface 12 to the far edge of the magnetic pole surface 12 of the thin film 3, and A conductive thin film 6 is provided on the magnetic pole face 12 of the thin film 5, reaching the magnetic pole face 12 from a portion slightly closer to the magnetic pole face 12 toward the far edge, and a second conductive thin film 7 is further provided thereon. This second conductive thin film 7 does not reach the magnetic pole face 12. On top of that, there is a magnetic thin film 8 that sufficiently covers the magnetic thin film 5 and the conductive thin films 6 and 7, and on top of that, there is a magnetic thin film 8 that sufficiently covers the magnetic thin film 5 and the conductive thin films 6 and 7. A second magnetic thin film 9 is provided to sufficiently cover the magnetic thin film 8 from the edge of the thin film 3 farther from the magnetic pole face 12.
5, 8, and 9 other than the magnetic thin film 3 formed in the groove 2 are configured so that all widths are the same, and the conductive thin films 6 and 7 are connected to the outside, so their sides are further on the substrate 1. The conductor thin films 10 and 11 are connected to each other. Although not shown, the conductive thin film is constructed in the same manner on the other side portions as well. After forming the thin film in this way, the magnetic pole face 12 and the surface of the substrate 1 continuous to the magnetic pole face 12 are polished and shaped.

The thin film magnetic head according to the present invention is constructed as described above, and has a magnetic thin film 5 constituting the main magnetic core.
Since there are magnetic thin films 3 and 9 constituting the auxiliary magnetic core covering the magnetic cores 3 and 8, the magnetic core becomes thicker and the head efficiency becomes higher.

On the other hand, the thickness of the pole chip, that is, the thickness of the core at the pole face 12, is only the thickness of the magnetic thin films 5, 8, and can therefore be made thinner, thereby increasing the recording density.

In addition, since the auxiliary core (magnetic thin films 3 and 9) does not reach the vicinity of the magnetic pole surface 12, the resistance to the magnetic flux in the area other than the vicinity of the magnetic pole can be reduced and the magnetic flux can be concentrated on the magnetic pole, which is useful for recording. Therefore, magnetic flux can be used effectively.

Such a thin film magnetic head can be manufactured as follows.

FIG. 2 is a diagram showing an example of the manufacturing process of the present thin film magnetic head. First, as shown in FIG. Grooves 21 are formed using known integrated circuit pattern forming techniques such as
form. This groove 21 extends in a direction perpendicular to the paper surface.

When a material other than silicon is used as the substrate, a thin film of silicon oxide can be formed on the substrate in advance, and then grooves can be formed in the same manner as described above.

Next, as shown in FIG. 2b, the groove 21 of the substrate 20 is
A thin film 22 of silicon oxide is formed by oxidizing the surface of a certain surface, and the surface is further metalized with a metal such as chromium or titanium to form a metal thin film layer 23. A magnetic thin film 24 having a thickness sufficient to fill the groove 21 is formed thereon by a known technique such as vapor deposition, sputtering, or electrodeposition. In this case, groove 2
Since this magnetic thin film 24 is not necessary in areas other than 1, the unnecessary areas are removed by known techniques such as chemical etching or ion milling.

In this way, a portion 26 of the magnetic thin film 24 remains only in the groove 21 of the substrate 20, as shown in FIG. 2c.

In FIG. 2c, the substrate 20 and the magnetic thin film 2
An insulating layer 25 made of silicon oxide or the like is provided on the surface of 6.

Next, as shown in FIG. 2d, a magnetic thin film 27, conductive thin films 28 and 30, magnetic thin film 31,
32 are sequentially stacked one on top of the other. 29 is an insulating layer provided between each thin film.

Only the conductor thin film 28 and the magnetic thin films 27 and 31 constituting the main magnetic core extend toward the right side of the drawing in FIG. The head air bearing surface 34 and the magnetic pole surface 35 are cut out and shaped by polishing or the like.
form.

Note that the magnetic thin films 27 and 31, 26 and 3
2 are connected to each other at positions beyond the conductor thin film 28 to reduce the magnetic resistance therebetween.

The manufacturing method described above can be used to manufacture multi-turn thin film magnetic heads having multiple conductor layers.

An insulating layer 2 provided between the conductive thin films 28 and 30
9 is for preventing short circuit current from occurring between the conductive thin films 28 and 30, and by adopting such a structure, a coil having the number of turns equal to the number of layers of the conductive thin films can be obtained. In this embodiment, a thin film magnetic head having a two-turn coil is obtained.

Between the magnetic thin films 31 and 32 and between the magnetic thin films 26 and 2
The insulating layer 29 between 7 and 7 is provided to improve high frequency characteristics in magnetic characteristics.

That is, most of the magnetic thin films used as the core of thin film magnetic heads are metal (alloy) materials such as Ni--Fe alloy (permalloy) and Fe--Si alloy (sendust).

Therefore, since the magnetic thin film is a conductor although it is a thin film, when high frequency driving is attempted, current will be concentrated on the surface of the conductor due to the skin effect.
Therefore, the loss caused by this current concentration becomes a problem. The insulating layer 29 has the effect of reducing concentration of this current and reducing the loss described above.

Further, since the insulating layer is also a nonmagnetic layer, by providing the insulating layer, it is difficult to form a domain wall structure called a free-flow magnetic domain within the magnetic pole pattern, and high magnetic permeability can be obtained. These factors lead to improvement in high frequency characteristics.

As mentioned above, by making the thin film coil multi-turn, the induced voltage or magnetic flux can be increased,
Head efficiency can be improved. Such multi-turn thin film coils are known, for example, from US Pat. No. 3,549,825. (Although the above-mentioned document describes forming a large number of one-turn coils in multiple layers, it is possible to form a multi-turn coil by changing the external connections.)・It can also be used in the structure of a track head, and in this case, the magnetic thin film for the auxiliary magnetic core (3, 2 in Figure 1)
26) in the figure can all be made in common for this head, cutting is not required for each head, and manufacturing is simple because it is sufficient to make one long common groove. .

According to the recently developed tapered etching method, it is possible to bring the end of the auxiliary magnetic core closer to the magnetic pole surface, thereby making it possible to further increase the recording magnetic field.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the effect of improving the head efficiency of the thin film magnetic head, increasing the recording density, and obtaining a large recording magnetic field.
Furthermore, according to the manufacturing method of the present invention presented here,
The manufacturing of the magnetic head according to the invention is facilitated, and especially for multi-track magnetic heads consisting of a large number of heads.
This has the effect of making it easier to manufacture the head.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view of a head embodying the present invention, and FIG. 2 is a diagram showing the manufacturing process of this head according to the present invention. In the figure, 1, 20 are substrates, 5, 8, 27,
31 is the main magnetic core, 3, 9, 26, 32 are auxiliary magnetic cores, 6, 7, 28, 30 are conductor thin films, 12,
35 is a magnetic pole surface.

Claims (1)

[Claims] 1. A main magnetic core made of a thin film, a part of which constitutes a magnetic pole, and an auxiliary magnetic core made of a thin film provided on the outside of the main magnetic core except for the magnetic pole part. A thin film magnetic head, characterized in that one of the auxiliary cores is constituted by a magnetic thin film provided inside a groove formed in a substrate. 2. forming a groove on the surface of the substrate except for a portion close to the surface of the substrate facing the magnetic recording medium, and forming a first auxiliary magnetic core in the groove using a magnetic thin film; forming a first main magnetic core with a magnetic thin film on the surface of the auxiliary magnetic core excluding the end opposite to the surface facing the magnetic recording medium and on the surface of the adjacent portion of the substrate; forming a thin film coil using a magnetic thin film on a surface of the first main magnetic core other than the end opposite to the surface facing the magnetic recording medium; and the end of the first main magnetic core. and forming a second main magnetic core using a magnetic thin film on the surface of the thin film coil;
forming a second auxiliary magnetic core using a magnetic thin film on the surface of the main magnetic core except for a portion close to the surface facing the magnetic recording medium; 1. A method for manufacturing a thin-film magnetic head, comprising the step of flattening a surface facing a recording medium.