JPS62229510A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To regulate the gap depth with high accuracy by gradually increasing the core width of either of a lower magnetic core and an upper magnetic core up to a position where a desired gap depth is obtained in the gap depth direction from a tape slide face. CONSTITUTION:The 1st magnetic core 2 is increased gradually in the direction of magnetic gap depth (gd) and the gap depth (gd) is detected by measuring the core width TW2 of the 1st magnetic core. The track width of the magnetic head depends on the core width TW1 of the 2nd magnetic core and the width TW1 is constant in the direction of the gap. Further, the core width is reduced near the sliding face and the relation of TW1<TW2 exists, then the magnetic flux is reduced near the gap and the reducing effect is obtained. Since the magnetic head pattern itself controls the gap, the accuracy of gap is improved without being affected by the deviation between the polishment progressing direction and the parallelism of the magnetic head pattern and by the shape of curved face of polishment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Invention 0 Utilization Division 2] The present invention relates to an a-film magnetic head suitable for VTRs and the like.

[Background of the invention]

With the demand for higher density magnetic recording, magnetic heads are becoming smaller and thin film magnetic heads are being developed. Thin film magnetic heads have many advantages, such as the ability to simultaneously form a large number of heads with minute patterns by applying conventional semiconductor manufacturing techniques, and the ability to manufacture multi-track heads at relatively low cost. The gap depth of this head is determined by polishing, and since the gap depth greatly affects the electromagnetic conversion efficiency of the magnetic head, it has been a challenge to improve the finishing accuracy of the gap depth.

For this purpose, for example, as described in JP-A-56-111120, a mark body for detecting the amount of polishing is formed adjacent to a thin film magnetic head pattern, and a composite of this magnetic head pattern and mark body is formed. A method of polishing to obtain the desired magnetic gap depth has been proposed. An example thereof is shown in FIG. In the figure, 2 is a magnetic core, 3 is a gap, 4 is a conductor, 7 is a connecting portion between the upper and lower magnetic cores, and 8 is a mark body. According to this method, since the magnetic gap depth can be detected by observing the mark body from the polished surface, the gap depth accuracy is improved. However, in this method, if a deviation occurs between the polishing direction and the parallelism of the magnetic head pattern, the gap depth detected by the mark body and the gap depth of the magnetic head pattern do not match. Also, because the polished surface is generally a curved surface.

Essentially, the gap depth between the mark body and the magnetic head pattern does not match, and furthermore, the head pattern density increases,
If the distance between the tracks is further narrowed, it may become difficult to secure a space for inserting the detection mark as described above.

[Object of the Invention] An object of the present invention is to provide a thin film magnetic head having a structure that overcomes the above-mentioned drawbacks and allows the gap depth of the magnetic head to be regulated with high precision.

[Summary of the invention]

The present invention has a structure in which the core width of either the first magnetic core or the second magnetic core is gradually increased in the polishing progress direction in order to directly detect the magnetic gap depth from the thin film magnetic head pattern itself. .

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1(a) is a plan view showing an embodiment of the thin film magnetic head according to the present invention, FIG. 1(b) is a cross-sectional view taken along line A-A, and FIG.
It is a sectional view of B.

1 is a non-magnetic substrate, 2 is a first magnetic core, 3 is a gap made of non-magnetic material, 4 is a conductor made of Cu, A1, etc., 6 is a second magnetic core, 7 is a first magnetic core 2 and a second magnetic core. 2 magnetic core 6
This is the connection part. The magnetic gap depth (gd) of the first magnetic core 2 gradually increases in the direction, and the gap depth can be detected by measuring the core width Tw2 of the first magnetic core. The track width of the magnetic head is determined by the core width Tw of the second magnetic core. Note that Tw is constant in the gap depth direction.

In addition, the first magnetic core 2 has a core width reduced near the sliding surface, and furthermore, Tw□ (Tw2), so that the magnetic flux is narrowed near the gap, resulting in a throttling effect.

In the present invention, since the gap depth can be controlled by the magnetic head pattern itself as described above, the gap depth can be controlled without being affected by the deviation in parallelism between the polishing progress direction and the magnetic head pattern or the curved shape of the polishing surface. accuracy is improved.

Next, the manufacturing method of the above embodiment will be explained with reference to FIG. FIG. 2 is a cross-sectional view of a main part showing a section taken along the line CC in FIG. 1.

(a) A magnetic thin film that will become a first magnetic core is formed on a nonmagnetic substrate 1 by vapor deposition, sputtering, etc., and a first magnetic core 2 is formed in a desired pattern by etching.

(b) Gap material 3. Conductor 4. An insulating layer 5 is formed.

(c) A magnetic thin film that will become the second magnetic core is formed by vapor deposition, sputtering, etc., and etched to form the second magnetic core 6 in a predetermined shape.

(d) Cut each chip of the thin film magnetic head pattern, polish the tape slide, and determine the gap depth. Since the core width Tw of the first magnetic core 2 gradually increases in the polishing direction, the gap depth can be detected by measuring Tw2.

In the above embodiment, only one chip is shown, but in reality, a large number of chips are arranged on the same substrate, and the processes up to the step shown in (C) are performed simultaneously on the substrate.

FIG. 3 shows another embodiment of the present invention, in which the core width of the second magnetic core 6 is changed. Gap depth during polishing is 2nd
It can be detected from the core width of the magnetic core 6.

The present invention is also effective for multi-track heads, and an example applied to a two-track head is shown in FIG.

2a, 2b are first magnetic cores, 3a, 3b are gaps, 4
a and 4b are conductors, and 6a and 6b are second magnetic cores. In this embodiment, the first magnetic core 2a.

Although the core width of the second magnetic core 2b is changed, the core width of the second magnetic cores 6a and 6b may be changed.

In FIG. 5, the first
An embodiment of the present invention is shown in which the magnetic core 2 and the second magnetic core 6 have a structure in which the core widths are the same.

The figure shows the Herad tip before the sliding surface was polished. When polished to the position indicated by the two-dot broken line, the first magnetic core 2
The core widths of the second magnetic core 6 and the second magnetic core 6 are made equal, and a desired gap depth is obtained.

In this embodiment, since the widths of the two magnetic cores match at the end of polishing, it is easy to determine whether polishing is complete. Furthermore, the fifth
Although the figure shows an example in which the core width of the first magnetic core 2 is changed, a configuration in which the core width of the second magnetic core 6 is changed may also be used.

FIG. 6 shows an example in which the core widths of both the first magnetic core 2 and the second magnetic core 6 are changed. The track width Tw□ is determined by the overlapping portion of the two cores, and is constant and does not change with respect to the polishing progress direction of the tape sliding surface. Further, the gap depth can be detected from the deviations Tw3 and 7w4 between the two cores.

In this embodiment, since the core widths of both the first magnetic core 2 and the second magnetic core 6 are larger than the track width Tw□, a magnetic flux throttling effect can be obtained in the gap between the two magnetic cores.

As described above, according to the present invention, since the gap depth can be detected directly from the magnetic head pattern, the gap depth can be regulated with high precision. Furthermore, the performance of the magnetic head can be improved due to the magnetic flux throttling effect.

〔Effect of the invention〕

According to the present invention, in the thin film magnetic head pattern, 1
By adopting a configuration in which the core width of the two magnetic cores gradually increases in the polishing direction of the tape sliding surface, the magnetic gap depth can be detected from the magnetic head pattern itself, so that the gap depth can be regulated with high precision.

[Brief explanation of drawings]

FIG. 1(a) is a plan view showing an embodiment of the present invention;
b) is a sectional view taken along the line A-A in FIG. 1(a) showing an embodiment of the present invention, and FIG. 1(C) is a cross-sectional view of FIG.
), and Figure 2 is a sectional view taken along line B-B of
3 and 4 are plan views showing the embodiment of the present invention, FIG. 5 is a plan view showing the magnetic recording pattern, and FIG. 6 is a conventional example. FIG. DESCRIPTION OF SYMBOLS 1... Non-magnetic surrounding plate, 2... First magnetic core, 3...
Gap, 4...Conductor, 6...Second magnetic core 2nd
Figure 3 Figure Tower 4 Figure 5 Figure 6 Figure 6 (α) (b) Procedural amendment (method) Indication of the case 1985 Patent Application No. 247065 Title of the invention Information on the person who corrects the thin film magnetic head Patent applicant name (510) Co., Ltd. +1 Manufactured by Hitachi
Oriyo Masato

Claims (1)

[Claims] 1. A thin film magnetic head comprising a nonmagnetic substrate, a lower magnetic core, a nonmagnetic spacer (gap), a conductor, an insulating layer, and an upper magnetic core, the lower magnetic core and the upper magnetic core. 1. A thin film magnetic head characterized in that the core width of either one of the above gradually increases in the gap depth direction from the tape sliding surface to a position at least at which a desired gap depth is obtained. 2. The thin film magnetic head according to claim 1, wherein the core widths of the lower magnetic core and the upper magnetic core match at a position where a desired gap depth is obtained. 3. The core widths of both the lower magnetic core and the upper magnetic core gradually increase from the tape sliding surface in the gap depth direction to a position where at least a desired gap depth is obtained, and the overlap width of the mutual cores increases as the gap width increases. The thin film magnetic head according to claim 1, characterized in that the thickness is constant in the depth direction.