JPS58100213A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To reduce the film thickness of a soft magnetic film to track width size efficiently at high yield, by finishing the depth of a groove to the film thickness size when a step or groove is worked in the soft magnetic film, and thus forming a gap surface. CONSTITUTION:On a nonmagnetic substrate 13, a soft magnetic film 14 is formed and step work of size D less than the film thickness size of the film 14 is performed by using a high-hardness cutting tool 15 to remove a removal part until the substrate 13 is exposed, forming a step having a gap surface 17. On the film 14 after the step work, a gap spacer film 13 having such a film thickness that the normal-directional size of the surface 17 is working gap and a soft magnetic film 19 are formed in order and the film thicknesses of the films 14 and 19 are reduced to track width size T to form the working gap 20. Then, an interlayer insulating film 21 and a soft magnetic film 22 are formed and a groove is formed in the film 22. On the film 22, a nonmagnetic material 26 is provided to fill the groove 25, and a nonmagnetic plate 28 is adhered thereupon; and a winding window 29 is bored at a prescribed position, thus manufacturing a head chip.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a magnetic head, and more particularly to a method of manufacturing a magnetic head suitable for manufacturing a narrow gap length magnetic head with good yield.

With the increase in recording density, it has become necessary to narrow the head operating gap, but the left and right magnetic cores 1.1, as shown in Fig. In the gap bonding method in which the magnetic cores 1 and 1' are mechanically butted together by sandwiching the gap spacer 2, the gap length determining factor is not only the dimension of the gap spacer 2, but also the difference between the surfaces of the magnetic cores 1 and 1' that are difficult to control. Due to the presence of gaps, the yield will decrease if a narrow gap length is attempted. For this reason, as shown in FIG.
The side surface of the step formed by [Fig. 2 (α) A] or the V-shaped groove formed by the diamond bite 7' [Fig. 2 Cb) A] is used as the gap surface 8, and the soft magnetic film 6.6' [ Figure 2 (α
A magnetic head has been proposed in which an operating gap and a head magnetic path are formed by sandwiching a gap spacer film 9 at the opening (A).

In the above proposed magnetic head, the gap spacer film 9 is the only factor determining the gap length, and a narrow gap length magnetic head with high dimensional accuracy can be manufactured with high yield. Since the step machining or 21-shaped groove machining of the soft magnetic film 6 in the trench is performed only with the diamond cutting tool 7°7', the cut pieces of the substrate 5 are taken into the diamond cutting tool 7.7' and the gap surface 8 is This may cause problems such as damage or cracks in the substrate 5. In addition, the soft magnetic film 6 constituting the head magnetic path
．． 6' has a two-layer structure with the gap spacer film 9 as an interlayer film, as in the example shown in FIG.
As shown in Figure (b) C, the diamond bite 1
1, grooves are formed in the soft magnetic film 6' up to the vicinity of the operating gap 10 of the soft magnetic film B, and the soft magnetic film 6 of the soft magnetic film 6' is
If the head track width is finished to be the same as the groove width above, the soft magnetic film 6' will peel off from between the layers due to processing stress, resulting in a problem that the yield will be significantly reduced.

The present invention has been made in view of the above, and its object is to form a magnetic field by forming an operating gap by sandwiching a gap spacer film between a first soft magnetic film and a second soft magnetic film. A magnetic head that can easily process steps or grooves that have a flat, scratch-free gap surface, and that can reduce the thickness of the soft magnetic film near the operating gap to the track width dimension with good yield. The purpose of this invention is to provide a method for manufacturing the same.

The first feature of the present invention is that when cutting a step or a groove in the first soft magnetic film, first, the step or groove is cut shallower than the thickness of the soft magnetic film using a high-hardness cutting tool. The gap surface is then formed by etching so that the step dimension or the depth of the groove becomes the film thickness dimension. The second feature is
In a magnetic head in which the soft magnetic film forming the head magnetic path has a two-layer laminated structure, and the thickness of the soft magnetic film in the operating gap portion is narrowed down to match the trunk width dimension, furthermore,
A groove with a depth shallower than the film thickness of the soft magnetic film is formed in the upper soft magnetic film near the operating gap formed by sandwiching the gap spacer film between the first soft magnetic film and the second soft magnetic film. This is done using a high-hardness cutting tool, and then etching is performed to reduce the film thickness of the grooved portion to the track width dimension.

An embodiment of the method of the present invention will be described in detail below with reference to FIGS. 3 and 4.

FIG. 3 is an explanatory diagram of the manufacturing process in the case of using a stepped side surface provided in a soft magnetic film as a gap surface. First, a first soft magnetic film 14 is formed on a non-magnetic substrate 13 using a thin film forming technique such as vapor deposition or sputtering, and a dimension D smaller than the film thickness of the soft magnetic film 14 is formed using a high hardness cutting tool 15. After processing the step, the soft magnetic film on the entire bottom surface of the step is removed by an etching method such as chemical etching or ion etching until the substrate 13 appears by an etching amount d, and the step having the gap surface 17 is removed. form (Fig. 3A). In addition, in the step processing described above, the gap azimuth angle is between the substrate 130 surface and the gap surface 1.
The angle θ formed with 7 can be arbitrarily selected depending on the shape of the high-hardness cutting tool 15. Next, a gap spacer film 18 and a second soft magnetic film 19 having a film thickness such that the dimension in the normal direction of the gap surface 17 is the operating gap length are sequentially formed on the soft magnetic film 14 after step processing using the above-mentioned thin film forming technique. A portion of the soft magnetic film 19019' is removed by polishing, and the thickness of the soft magnetic film 14.19 is reduced to the track width dimension T to form the operating gap 20 (FIG. 3B). Next, the interlayer insulating film 21. A third soft magnetic film M22 is formed by the above-mentioned thin film forming technique, and a groove having a downward trapezoidal cross section with a depth D' smaller than the film thickness dimension is formed in the soft magnetic film 22 using a high-hardness cutting tool 23 (Fig. 3). C). After the above groove processing, the etched portion 24 (etching amount d') of the soft magnetic film 22 is removed by the same etching method as described above until the bottom surface of the groove reaches the interlayer insulating film 21, thereby forming a groove 25 (FIG. 6D). ).

After performing the above processing, as shown in FIG.
Alternatively, as shown in FIG. 3F, the groove 25 is filled with glass 27 and a non-magnetic plate 28 is bonded thereon. Thereafter, as shown in FIG. 3G, a winding window 29 is opened at a predetermined position by ultrasonic machining to complete the manufacture of the head chip.

Note that in processing the groove 25, if the difference in etching rate between the interlayer film 21 and the soft magnetic film 22 is not very large, such as by ion etching, etching may be used to remove the soft magnetic film near the operating gap 20. Since it is possible to reduce the thickness to the track width dimension, it is not necessary to reduce the thickness of the soft magnetic film 14.19 to the track width dimension T in the polishing process for removing the soft magnetic film 19019' portion shown in FIG. 3B. There is no need for finishing, and any dimension of one dimension T or more is sufficient.

However, if there is a large difference in etching rate as described above, it is necessary to finish the track width dimension T as described above.

In Figure 3G, the magnetic path consists of soft magnetic films 14, 22 and 19.
．． However, if the head magnetic path is composed of a set of single-layer films, the first soft magnetic film 14 is formed to have a thickness equal to or larger than the track width dimension T, as shown in FIG. 6B. , polishing was performed until the gap spacer film 1B was reached, and as shown in FIG.
The thickness of the soft magnetic film in the vicinity of the operating gap 20 may be narrowed down to the track width dimension T by only groove processing.

FIG. 4 is an explanatory view of the manufacturing process in the case where the side surface of the V-shaped groove provided in the soft magnetic film is used as the gap surface. in this case,
First, the first soft magnetic film 14 is formed on a non-magnetic substrate 16 using a thin film forming technique such as vapor deposition or sputtering as shown in FIG. A V-shaped groove D is formed, and the etched portion 31 (etching amount d) of the soft magnetic film 14 is removed by an etching method such as chemical etching or ion etching until the V-shaped apex reaches at least the surface of the substrate 130. A surface 32 is formed (FIG. 4A). Note that the gap azimuth angle θ can be freely determined depending on the shape of the high-hardness cutting tool 30 and the security ink conditions of the cutting tool 30. The V-groove may also have a downward trapezoidal shape, as shown in broken lines in FIG. 3C. Next, an insulating gap spacer film 33 and a second soft magnetic film 34 having a film thickness such that the dimension in the normal direction of the gap surface 32 is the operating gap length are placed on the soft magnetic film 14 after the KV groove has been processed. The thin film is formed using the above-mentioned thin film forming technique, and the groove is processed with a high-hardness cutting tool 23 until the bottom surface reaches at least the bottom of the V-shaped groove formed in the soft magnetic film 34, that is, the groove depth is D'. Figure 4B). The second soft magnetic film 34 is formed to have a thickness equal to or greater than the depth of the V-shaped groove described above. Next, the etched portion 36 having the dimension d' is removed by ion etching until the thickness of the soft magnetic film near the operating gap 35 reaches the track width dimension T.
7 (Figure 4C).

Next, the glass 27 is embedded in the groove 37, the non-magnetic plate 28 is glued above it (Fig. 4D), and the winding window 29 is placed in a predetermined position.
Complete the drilled head chip by ultrasonic processing (4th
Figure E).

In FIG. 4E, the magnetic path is constituted by soft magnetic films 14.34 separated on the left and right, and the operating gap 35 is formed between the first soft magnetic film 14 on the left side and the second soft magnetic film 34 on the right side. is formed. Since the gap spacer film 33 is an interlayer film between the soft magnetic films 14 and 34 except for the gap plane, if it is an insulator as described above, it will also serve as interlayer insulation, but it does not need to be an insulator. . Furthermore, different materials may be used for the V-shaped groove portion in FIG. 4 and the other interlayer portions of the soft magnetic film 14, 34. The ion etching in FIG. 4C may be chemical etching, but if the etching rate for the interlayer film of the soft magnetic film 14.34 is sufficiently smaller than the etching rate of the soft magnetic film 34, the etching in FIG. It is necessary to set the thickness of the soft magnetic film 14 to the track width dimension T. Further, in the step of Figure 4, the non-magnetic material may be deposited to a thickness of several tens of micrometers using a coating technique or a thin film forming technique as in Figure 3E.

In Figs. 3 and 4, the steps shown in Fig. 3A are processed, the V-shaped grooves shown in Fig. 4A, and the grooves processed with a high-hardness cutting tool shown in Fig. 3C1 and Fig. 4B are processed in front of the head magnetic path. It may be only near the operating gap of the head, or it may extend from the front to the rear of the head magnetic path. The material of the high-hardness cutting tool does not necessarily have to be the conventional diamond cutting tool. Depending on the material of the soft magnetic film that constitutes the head magnetic path, it may be made of high-speed steel, which is a common tool material. Naturally, sapphire, ruby, etc. can be used, and ceramic bits and carbide bits may also be used.

According to the above-described embodiment of the manufacturing method of the present invention, when machining a step or a single-shaped groove having a gap forming surface, the high hardness (P) 15.30 does not reach the substrate 13, which has been a problem in the past. It is possible to prevent cracks from occurring and damage to the gap forming surface 17.32.

Also, in the groove machining shown in FIG. 3 C0 and FIG.
．． Since it does not reach the space between the layers 34 and 14, the problem of peeling of the soft magnetic film 22, 54 from between the layers can be avoided.

As explained above, according to the present invention, it is possible to easily process steps or grooves having a flat gap surface without scratches, and to reduce the thickness of the soft magnetic film near the operating gap with good yield. This has the effect of narrowing down the dimensions to the track width dimension.

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional ferrite magnetic head, Figure 2 is a manufacturing process explanatory diagram for explaining the manufacturing method of a conventional magnetic head using a soft magnetic film, and (a) is a gap formed on the side surface of a step. (b) is a diagram when the side surface of the V-shaped groove is used as the gap forming surface, and FIGS. 3 and 4 are diagrams showing one method for manufacturing a magnetic head using the soft magnetic film of the present invention. These are manufacturing process explanatory diagrams for explaining the embodiment, in which FIG. 3 is a diagram when the step side surface is used as the gap forming surface, and FIG. 4 is a diagram when the V-shaped groove side surface is used as the gap forming surface.

Claims (1)

[Claims] 1. The operating gap and head magnetic path are created by sandwiching a gap spacer film between a first soft magnetic film and a second soft magnetic film, each of which has a step or groove whose side surface serves as a gap surface. In the formed magnetic head, when cutting a step or groove in the first soft magnetic film, first cut the step or groove shallower than the thickness of the soft magnetic film using a high-hardness cutting tool. A method for manufacturing a magnetic head, characterized in that the step size or the depth of the groove is finished to the film thickness size by etching to form a gap surface. 2. An operating gap is formed by sandwiching a gap spacer film between a first soft magnetic film and a second soft magnetic film, each having a step or groove whose side surface becomes a gap surface, and a soft magnetic field that forms a head magnetic path. A magnetic head in which the film has a two-layer laminated structure and the thickness of the soft magnetic film in the operating gap portion is narrowed down to match the track width dimension. When cutting a step or groove in the first soft magnetic film, first cut the step or groove shallower than the thickness of the soft magnetic film using a high-hardness cutting tool, and then etching the step or groove. Alternatively, the depth of the groove is finished to the film thickness dimension to form a gap surface, and a working gap is formed by sandwiching a gap spacer film between the first soft magnetic film and the second soft magnetic film. A groove with a depth shallower than the film thickness of the soft magnetic film is formed in the upper layer near the soft magnetic film using a high-hardness cutting tool, and then etching is performed to make the film thickness of the grooved portion equal to the track width dimension. A method for manufacturing a magnetic head, which is characterized by narrowing down the steps to: