JPS58179924A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To reduce the distortion of a substrate and to improve the yield of production for a magnetic head having small track width and small gap length, by attaching the 1st soft film 2 in a grid form on the surface of a nonmagnetic substrate and only the areas where each head chip is formed. CONSTITUTION:A nonmagnetic metallic film 13 and then the 1st layer soft magnetic film 14 are attached in a grid form on a nonmagnetic substrate 1 by a mask sputtering process, etc. Then a channel is cut to the film 14 with a diamond bite, etc. so as to obtain a V-shaped or adversely trapezoidal cross section and to obtain a fixed azimuth for one side 16 of the channel sloping surfaces to the direction of the normal line of the substrate surface. A gap spacer film is attached to the sloping surface 16 of the channel 15, and then the 2nd layer soft magnetic film 17 is formed on the film 14. Then a channel is cut to the film 17 with a cutter 18 to form a protecting film 20, and a winding window 9 is drilled. Then a chip is obtained. The film 2 is formed into a grid shape to prevent the generation of stress to the substrate 1, the inaccurate control to the depth of the channel and the generation of flaws to the channel surface 16. Thus the yield of production is improved for a magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a narrow gap length magnetic head.

Conventional mechanical butt-type gap forming methods have difficulties in mass producing narrow track width, narrow gap length heads with a specified azimuth angle suitable for short wavelength recording. A magnetic head has been proposed in which one slope 4 of #l13 formed on the first rvi-th soft magnetic film 2 adhered on a non-magnetic substrate l is used as an operating gap surface.

In the above-mentioned invention, when the second layer soft magnetic film 2 having a film thickness of IQgg++ or more is applied directly to the non-magnetic substrate 1, the substrate 1 is distorted due to the stress accumulated inside the soft magnetic film. The skeleton substrate strain number makes the control of the cutting depth inaccurate when cutting grooves on the soft magnetic film 2 with the ultra-high hardness cutting tool 5, and depending on the substrate position, the cutting tool 5 can even reach the non-magnetic substrate. reaches. As a result, the resulting non-magnetic substrate is cut into small pieces, which causes scratches 11 on the groove slope plate serving as the operating gap surface. (FIG. 1D) Furthermore, there is a problem in that the angle θ2 between the substrate surface normal direction and the groove slope 4, which is the azimuth angle, varies depending on the substrate position (FIG. 1E).

Attempts have also been made to solve the above problem by forming a nonmagnetic metal film 12 such as SUS 310 between the nonmagnetic substrate 1 and the second layer soft magnetic film 2 using sputtering cape thin film formation technology as shown in Figure 2. Although the occurrence of scratches 11 could only be suppressed when the thickness of the nonmagnetic metal film 12 was 6 μm or more (FIG. 2D), all of the above-mentioned problems have not been sufficiently solved.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a technology for mass-producing heads in which the azimuthal track width and gap length are precisely regulated.

In the present invention, at least the first soft magnetic layer 2 is formed on a non-magnetic substrate l.
The problem of the prior art described above was solved by attaching it in a checkered pattern only to the parts constituting each head chip, rather than to the entire surface of the substrate l, thereby reducing the distortion of the substrate l.

FIG. 3 shows a specific embodiment of the present invention. A nonmagnetic metal film 13 and a first layer soft magnetic film 14 are deposited on the nonmagnetic substrate 1 in this order by mask sputtering, mask vacuum evaporation, or the like to a predetermined film thickness in a grid pattern (FIG. 3A). A diamond cutting tool 5 (cutting ultra-high hardness of other materials) with a predetermined shape so that the rear cross-sectional shape is a two-letter shape or an inverted trapezoid, and one of the groove slopes 16 forms an azimuth angle θ with respect to the normal direction of the substrate surface. Groove cutting is performed on the soft magnetic film 14 using a cutting tool. (FIG. 3B) It is assumed that the thickness of the soft magnetic film o4 or more does not reach the nonmagnetic base plate 1 at any position on the fIIl depth substrate.

As described above, the gap spacer film 6 is adjusted so that the film length of the IS slope 16 in which the busy groove 15 is formed is equal to the operating gap length.
The first layer soft magnetic film 1 is formed by mask sputtering, mask vacuum evaporation, etc. with the gap spacer film 6 in between.
4, a second layer soft magnetic film z7 of a constant film piece is attached. Next, in order to define the track width dimension, use a diamond cutting tool 18 (an ultra-high hardness cutting tool made of other materials is also possible) with an inverted trapezoidal cross section to determine the operating gap 1.
Groove cutting is performed on the first layer soft magnetic film 1γ near 9 (FIG. 3C). After the track width size has been regulated, a protective film 20 made of a non-magnetic material with excellent wear resistance and having a thickness of 10 μm or more is formed on the soft magnetic film 17 to protect the soft magnetic film 17.
After machining 9 holes for winding on the fixed positioning unit, cut off the part to which the soft magnetic film is not attached to form a head chip (
Figure 3D).

The first layer soft magnetic film 14 having a lattice pattern may be formed by depositing it on the entire surface of the substrate and then removing unnecessary portions by etching, electrolytic polishing, or the like.

In order to regulate the track width dimension, the first layer soft magnetic film 17 may be grooved by one-ion milling, etching, electrolytic polishing, electric discharge machining, etc. in addition to cutting with a diamond cutting tool.

As in the present invention, non-magnetic gold film 1s, soft magnetic film 14
If 1γ is formed in a lattice pattern, the strain induced in the substrate can be reduced compared to the case where the metal film or soft magnetic film is formed over the entire surface of the substrate 1.

Therefore, the thickness of the non-magnetic metal film 13, which was required to be 6 μm in the conventional method, can be reduced to about 2 μm, which is the control limit for grooving using the diamond cutting tool 5, and manufacturing time can be shortened.

By reducing the strain induced in a warped substrate, previously the head with the desired azimuth angle could only be obtained from a part of the substrate, but now it is possible to greatly reduce the error in the azimuth angle over the entire substrate, and the head with the desired azimuth angle can be obtained from only a part of the substrate. It may be possible to obtain an azimuthal head from a large portion of the substrate. In other words, the yield of manufacturing heads with narrow track widths and gap lengths can be greatly improved.

[Brief explanation of the drawing]

Figure 1 is a manufacturing process diagram of a conventional magnetic head in which the operating gap is a groove slope formed in a soft magnetic film, Figure 2 is a process diagram showing a conventional example in which a non-magnetic metal film is used, and Figure 3 is FIG. 4 is a process diagram of a further embodiment of the method for manufacturing a magnetic head according to the present invention. l: non-magnetic substrate, 2: first layer soft magnetic film, 3: #, 4
: Operating gap surface, 5: Diamond bite, 6
: gap spacer film, 7=second layer soft magnetic film, 8: protective film, 9: winding window hole, lO: operating gap, 11:
Scratches, 12 = non-magnetic metal film, 13: non-magnetic metal film,
14: First layer soft magnetic film, 15: #ll, 16: Operating gap surface, 17: Second layer soft magnetic film, 18: Diamond bite, 19: Operating gap, 20: Protective film.

Claims (1)

[Claims] 1 One of the slopes of the groove formed by cutting the first layer soft magnetic film adhered on a non-magnetic substrate with a high-hardness cutting tool is used as the operating gap surface, and the first layer soft magnetic film subjected to the processing and the second layer soft magnetic film are A method for manufacturing a magnetic head, wherein at least the first layer soft magnetic film forms a lattice pattern in the step of manufacturing a magnetic head forming an operating gap that is not parallel to a substrate surface with a magnetic film.