JPS61284816A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To obtain a thin film magnetic head which improves the accuracy of a track width and decreases variance without generating cracks around a lower magnetic material by forming a steep slope near the gap in the sectional shape of the lower magnetic material of a thin film magnetic head and forming a gentle slope to the part apart therefrom. CONSTITUTION:This head is so constructed in section as to have both of the slope which does not constitute a columnar structure and the steep slope which decreases the variance in the track width by a lap quantity. More specifically, the steep slope 21 is formed on the gap 4 side of the lower magnetic material 2 and the gentle slope 22 is formed on the opposite side. The track width is substantially maintained constant by the steep slope 21 without changing with the lap quantity. Since the greater part of the slope is the gentle slope, the range where the abnormal quality film is generated by the steep slope is small or such film is not generated at all. There are practically no problems and the cracks are hardly generated particularly when the film thickness of the gentle slope part is made >=1/2 the film thickness of the entire part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thin film magnetic head, and particularly to improving the precision of track width.

[Background of the invention]

In a thin film magnetic head manufactured by repeating film formation and etching, Japanese Patent Application Laid-Open No. 48-94409 discloses forming a non-magnetic material at the same height as the lower magnetic material. However, they were not aware of the problem caused by the cross-sectional shape of the lower magnetic material, which turned out to be an important problem in actual use.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thin film magnetic head with a magnetic material embedded in the bottom having a highly accurate track width.

[Summary of the invention]

The key point of the present invention is that the cross-sectional shape of the lower magnetic body of the thin-film magnetic head has a steep slope near the gap, and a gentle slope in the remote area. The embodiment shown in FIGS. 1 and 2 and the third embodiment
This will be explained using Figure (,) (b) (Q).

FIG. 1 shows a sectional view of a thin film magnetic head in which a lower magnetic material is patterned and embedded with a nonmagnetic film. 1 is a non-magnetic substrate such as glass or ceramic; 2 is a patterned lower magnetic body; 3 is a non-magnetic substrate such as glass or ceramic;
is 5i02. It is a non-magnetic material such as A22Qs. 4 is 5
Gap forming material such as 102, At203, 5) L
, Cu, etc. thin film coil.

6 is 5102, an insulating material such as polyimide resin, and 7 is an upper magnetic material, which is made of sendust, Co-based amorphous alloy, etc. as in 2. 7 constitutes a magnetic circuit with the lower magnetic body 2 via the gap forming material 4. The manufacturing method for non-head is I.
The photo-etching process is the same as that used for manufacturing C and the like. That is, this is a method in which film formation and etching are repeated sequentially starting from the substrate 1.

The present invention is characterized by the cross-sectional shape of the lower magnetic body 2. FIG. 2 is a sectional view of section AA in FIG. 1, showing the tape sliding surface. The lower core 2 has a steep cedar forest 21 with respect to the substrate near the gap 4.
The opposite side has a cross-sectional structure with a gentle cedar forest 22. When a nonmagnetic material is formed on an uneven part of a steep surface, whether by vacuum deposition or sputtering, the formed film has a columnar structure with low density. This columnar structure structure not only has a low density but also has a low mechanical strength. For this reason, cracks were easily generated due to various stresses such as thermal history during the manufacturing process.

Therefore, it was decided that the slope of the lower magnetic body 2 should be made to have a gentle slope that does not form a columnar structure, and as a result of study, it was found that the crural point thereof was at 45° to 50°.

On the other hand, the track width of this head is determined by the length t of the lower magnetic body 2 in contact with the gap material 4.

If the inclination angle of the lower magnetic body is gentle, the track width will vary significantly depending on the amount of overlap in the process of lapping the lower magnetic body 2 and the non-magnetic body 3 on the same surface. Particularly when a large number of heads are arranged on a substrate and the heads are manufactured at the same time, warping of the substrate is also a factor, resulting in heads having different track widths within the substrate, which causes a decrease in manufacturing yield.

The present invention is a head having a cross-sectional structure that includes both an inclined surface that does not cut the columnar structure and a steep inclined surface that reduces variations in track width due to the amount of overlap. That is, a steep slope 21 is formed on the gap 4 side of the lower magnetic body 2, and a gentle slope 22 is formed on the opposite side. Due to the steep slope 21, the track width hardly changes depending on the amount of lap, and on the other hand, since most of the slope is a gentle slope, the area where a foreign film is generated due to the steep slope is small or does not occur at all. In particular, when the film thickness of the gently sloped portion is set to 4 or more of the total film thickness, there is no practical problem and the occurrence of one crack is hardly observed.

Figures 3(a), (b), and (0) show a method of forming a steep slope on each gear and a gentle slope on the opposite side. The device is an ion milling device and the diagram is omitted. 8 is a mask for ion milling (: r, gold M such as W, inorganic material such as AtzQs, 1 polyimide-based organic material.

When the substrate 1 is tilted and rotated with respect to the irradiation direction of the Ar ion beam, the irradiation direction of the Ar ion beam becomes as shown in 9 with respect to the substrate 1. As a result, the lower magnetic body 2
Shown in (b). A desired shape can be formed. 3rd p (c
) is a step in which the mask material 8 is removed by etching and the non-magnetic material 3 is deposited. 1° indicates the lap surface, and the lower magnetic body 2
flattening of the non-magnetic material 3 is completed.

In this embodiment, the slope is formed with a steep slope and a gentle slope, but it is also effective to change the slope from a steep slope to a gradual slope in multiple stages or a continuous slope.

FIG. 4 shows another embodiment of a thin film magnetic head.

In this case, the gap 4 is formed in a direction substantially perpendicular to the substrate 1, and the magnetic recording medium runs down the top surface of the figure.As the magnetic recording medium runs down, the magnetic cores 71 and 72 are worn out, and the gap depth changes. become.

Here, if the magnetic cores 71 and 72 are made of steep slopes and steep slopes according to the present invention, the head will have a trunk width that does not change until the steep slope part disappears.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a thin-film magnetic head with high accuracy and less variation in track width without cranking around the lower magnetic body. Alternatively, a thin film magnetic head whose C track width does not change due to head wear can be provided.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the configuration of a thin film magnetic head according to an embodiment of the present invention, Figure 2 is a partial view showing the tape sliding surface of the thin film magnetic head of the present invention, and Figure 3 is a cross-sectional view showing the structure of a thin film magnetic head according to an embodiment of the present invention. FIG. 4 is a cross-sectional view showing a method of forming the body shape, and FIG. 4 is a perspective view of a thin film magnetic head of another embodiment. 1... Substrate 2... Lower magnetic body 6... Non-magnetic material 4... Gap forming material 5... Coil 7... Upper magnetic body

Claims (1)

[Claims] 1. A first magnetic material, a non-magnetic material, a gap material on the substrate,
A thin film magnetic head in which a coil, a second magnetic material, etc. are sequentially laminated in a predetermined shape, and the first magnetic layer is characterized in that the cross-sectional shape of the first magnetic layer has both a steep slope and a gentle slope. Thin film magnetic head.