JPS6286515A - thin film magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a magnetic head used for V'rR, etc., and particularly to a thin film magnetic head suitable for realizing long-life and highly reliable recording and reproducing characteristics. Regarding.

[Background of the invention]

A conventional thin film magnetic head generally has a structure described in Japanese Patent Laid-Open No. 55-8752i%. In other words, the magnetic layer that forms the magnetic core has a thickness of at most 5μ or less, and in order to perform recording and reproduction with a film thickness of It is true. This is not much of a problem when using the conventional thin-film magnetic head described above in a 70-ring system (with space between the recording medium and the head) such as in a hard disk, but it is not a problem when using the conventional thin-film magnetic head in a 70-ring system (with a space between the recording medium and the head), such as in a VTR, but it does not pose much of a problem when using the conventional thin-film magnetic head in a 70-ring system (with a space between the recording medium and the head), such as in a VTR, etc.; When used for contact (contact), the problem arises that the wear life of the head is short because the gap depth is as small as 5 μm or less.

On the other hand, for the purpose of increasing the gap depth, in order to increase the efficiency of narrowing the magnetic flux, Japanese Patent Laid-Open No. 55-875
As shown in Figure 2 P of Publication No. 25, winding 1
Attempts have been made to widen the cores of p, , p, in the 4th region, but sufficient magnetic flux restriction has not been achieved in the cores near the gap, which determine the gap depth (if the magnetic flux restriction core shape is used, the head track width changes due to wear), and it has not yet been possible to achieve a large gap depth.

[Purpose of the invention]

An object of the present invention is to provide a thin film magnetic head that effectively restricts the magnetic flux in the vicinity of the gap and achieves long-life and highly reliable ζ-series reproduction characteristics.

[Summary of the Invention] The present invention is characterized in that the shape of the head sliding surface of the core is such that the lower core widens as it moves away from the gap surface.
The upper core is also a fan-shaped core that widens as it moves away from the gap surface, and has a magnetic flux constriction effect in the thickness direction of the thin film core in the vicinity of the gap, and further improves the above effect by using a magnetic substrate. The multilayer structure is constructed such that the interlayer material surface and the interface between the lower core and the magnetic substrate are non-parallel to the gap surface, thereby reducing eddy current loss and contour effects.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a sliding surface of a thin film magnetic head according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A--A in FIG. In the same figure, 1 a magnetic substrate having a dogleg-shaped protrusion;
2, 2α, 24, 2a are lower cores made of multilayer soft magnetic films, 5α, 5b are interlayer material layers, 4 is a non-magnetic filling material, 5 is a gap material for regulating the gap length, 8 is a non-magnetic material. Interlayer materials 66a, 6h, and be are upper cores made of multilayer soft magnetic films, 7a and 7 are interlayer materials, 9 is a protective film, 10 is a protective plate, and 11 is a thin film coil.

In this way, the upper core 6 is shaped like a fan whose core width increases as the distance from the gear hub material 5 increases, giving the magnetic flux a narrowing effect in the film thickness direction, and the lower core 2 is made into a dogleg-shaped core to improve magnetic properties. By concentrating the magnetic flux from both @ faces of the protrusion of the substrate 1, it is possible to increase the gap magnetic field in the gap 5 and improve the recording ability. In conventional thin-film magnetic heads, it was not possible to create a narrowing effect on the magnetic flux near the gap, resulting in a gap depth of at most 5 μm, resulting in a short head wear life. In the embodiment of the present invention, since the recording ability is improved, the gap depth can be increased, and the wear life of the head is significantly improved.

In addition, the lower core 2 and the upper core 6 have a multilayer structure, the interlayer materials 5α and 5b have a dogleg shape, and the interlayer materials 7a and 74 have a fan shape parallel to the upper end surface of the upper core 6. It is possible to reduce eddy current loss when used in the area, and since the interface between each interlayer material 5a, 5b, 7a, 7h and the lower core and magnetic substrate is non-parallel to the gap 5 surface, each The so-called contour effect, in which the interlayer material and the boundary surface become a pseudo magnetic gap and reproduce a pseudo signal, can be reduced by the azimuth loss.

Furthermore, the core materials 2 and 6, which are relatively easy to wear, are reinforced with 1.10, a material that is hard to wear, in the direction of travel of the recording medium, thereby reducing uneven wear between the core materials and the magnetic substrate and increasing the wear life. can be made longer.

5, FIG. 4, FIG. 5, and FIG. 6 illustrate the second embodiment of the present invention.
5. This is a surface showing the sliding surface of the thin film magnetic head of the fifth example. In the second embodiment shown in FIG. 5, the lower core 2 is configured to have a core width smaller than the entire width of the head sliding surface, and in the fifth embodiment shown in FIG. 4, the lower core 2 is convex downward. In the fourth embodiment shown in FIG. It is formed on the substrate 1.

In each of the embodiments constructed in this way, the same effects as shown in the first embodiment can be obtained.

Hereinafter, a specific manufacturing method for the first embodiment of the present invention will be described using FIG. 6. In FIG. 6(α), substantially dogleg-shaped protrusions are formed on a magnetic substrate 1 made of ferrite or the like by machining or etching. In the figure, the protrusion shape is linear, but it may be curved upward and downward as shown in FIGS. 4 and 5.

Next, in (h), soft magnetic 1F42 such as sendust or amorphous alloy is used as an interlayer material and Sin.

Laminated with Al2O2 etc. The total film thickness is
The thickness is about 30 μm, and the number of layers is five in this embodiment, but the number of layers may be changed depending on the frequency band used. In (C), a thin film is formed as the non-m@ body 4 or a low melting point glass or the like is poured into the material, and then it is flattened by a method such as wrapping. At this time, the lapping mechanism is controlled so that the core width of the lower core 2 exposed to the substrate 1 is approximately the width of the track. In (d), a gap material 5 is formed to regulate the gap length, and although not shown in the figure, a thin film coil 11 and an interlayer insulating film 8 are formed as shown in FIG.
d) As shown in K, the gap part of the interlayer insulation g8 is set at an angle α1.
Teba etching with. If the Taber angle α1 becomes too large, it will deteriorate the film properties of the upper core 6a formed above.
If it becomes too small, the fringing magnetic field between the upper and lower cores will increase, which will impede the recording and reproducing characteristics. False is chosen. (Ri and Cf
), after forming the upper core 6α, the mask material 12 is patterned into a substantially arc shape, and the arc shape of the mask material 12 is transferred to the upper core 6a by a technique such as ion milling. In (!I), the interlayer material 7a7b and the upper core 6b,
6c are sequentially stacked. In (A), the excess upper part 76b, esc on the interlayer material B is removed by etching.

(i) Now, protection! After forming II & 9, it is flattened, a protective plate 1o is attached, and the head sliding surface is shaped by machining etc., resulting in the first embodiment of the present invention shown in FIGS. 1 and 2. A thin AM head is obtained. Other embodiments can also be made using similar manufacturing methods.

〔Effect of the invention〕

According to the present invention, the shape of the head sliding surface of the core is such that the lower core becomes wider as the distance from the gap surface increases (an approximately square core,
The upper core is a fan-shaped core that becomes wider as it moves away from the gap surface, and has a narrowing effect in the thickness direction of the thin film core near the gap, and further improves the above squeezing effect by using a magnetic substrate. The core has a multilayer structure, and the interlayer material surface and the interface between the lower core and the magnetic substrate are configured to be non-parallel to the gap surface, reducing eddy current loss and contour effects, resulting in long life and A thin film magnetic head that realizes highly reliable recording characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a sliding surface of a thin film magnetic head according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A in FIG.
FIG. 5, FIG. 4, and FIG. Fifth. 6th diagram showing the sliding surface of a thin film magnetic head, which is the fourth embodiment.
Figures (α) to (&) are process diagrams showing the manufacturing method of the present invention. 1...Magnetic substrate 2e2a*2hm2cmT Part core 6.6α, 6h, 6e...Upper core 5a, 5, 7a, 74...Interlayer material 11...Thin film coil 1 Fig. 3 Kuzuo map

Claims (1)

[Claims] 1. In a magnetic head formed by laminating thin films such as a lower core, a gap material, a coil, and an upper core on a magnetic substrate, at least the shape of the head sliding surface of the lower core is A thin film magnetic head characterized in that the core has a generally dogleg shape that widens as it moves away from the gap material surface, and the head sliding surface of the upper core has a fan-shaped core that widens as it moves away from the gap material surface. 2. The lower core and the upper core have a multilayer structure, the interlayer material of the lower core is parallel to the dogleg-shaped lower core and the boundary surface of the magnetic substrate, and the interlayer material surface of the upper core is the upper end surface of the fan-shaped upper core. Parallel to and both of the above interlayer material surface and boundary surface,
The thin film magnetic head according to claim 1, characterized in that the thin film magnetic head is configured to be non-parallel to the surface of the gap material. 3. The angle between the side edge of the upper core and the gap material surface is α
_1, the angle between the side edge of the lower core and the gap material surface is α
2. The thin film magnetic head according to claim 1, wherein α_1 and α_2 satisfy the following relational expressions: α_2>α_1 and α_2+α_1≧60 degrees.