JPS63288407A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To decrease generation of a contour effect by butting blocks from which high saturation magnetic flux density films are partly removed against each other via a magnetic gap in such a manner that at least part of the high saturation magnetic flux density films face each other and joining the blocks by a 2nd nonmagnetic material having the m.p. lower than the m.p. of a 1st nonmagnetic material. CONSTITUTION:Grooves 2 parallel with each other are formed at a prescribed pitch on one end face of the block 1 consisting of a high magnetic permeability material and the 1st nonmagnetic material 3 is packed into the grooves 2. The end face is then ground until the high magnetic permeability material is exposed and thereafter, the high saturation magnetic flux density film 4 is deposited thereon. The blocks from which the high saturation magnetic flux density films 4 are partly removed are butted against each other via the magnetic gap (g) in such a manner that at least part of the films 4 face each other. These blocks are then joined by the 2nd nonmagnetic material 5 having the m.p. lower than the m.p. of the 1st nonmagnetic material 3. The production without exposing the blocks to a high temp. after the formation of the films 4 is thereby executed and the inter-diffusion in the boundary part between the high magnetic permeability material and the high saturation magnetic flux density material is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic head, and in particular, the present invention relates to a method for manufacturing a magnetic head, in particular a magnetic head in which the vicinity of the magnetic gap is formed of a high saturation magnetic flux density film;
The present invention relates to a method of manufacturing a magnetic head in which most of the magnetic core is made of a high permeability magnetic material.

[Conventional technology]

In recent years, with the demand for high-density recording in magnetic recording and reproducing devices such as VTRs and video floppies, so-called metal tapes, metal sheets, etc., which have a large coercive force Hc, have come to be used as recording media. A head material for a recording/reproducing magnetic head compatible with a magnetic recording medium having such a large coercive force is required to have a high saturation magnetic flux density Bs and a high magnetic permeability.

On the other hand, for example, ferrite materials, which have conventionally been widely used as magnetic head materials, have a problem of low Bs. Sendust (Fe-Al-8t alloy) with high Bs
Proposals have been made to use bulk materials such as alloys for magnetic cores. However, when a metallic magnetic material is used for the core material, eddy current loss becomes a problem and high magnetic permeability in a high frequency region cannot be obtained.

For this reason, studies were conducted to use thin film formation technology to create a multilayer film by alternately laminating metal magnetic materials and insulators as a core material. As a result, as shown in Fig. 11, a non-magnetic guard material 11.
A magnetic head has been proposed in which a multilayer ferromagnetic metal thin film 10.10' made of i02 or the like is sandwiched, and a track and a magnetic gap 12 are formed by the multilayer film 10.10'. Although this type of magnetic head is capable of narrowing the track, the ferromagnetic film 10.10' must be formed on the ceramic substrate 11.11' to a thickness corresponding to the track width. Thin film forming techniques have a limit to their film growth rate, and it takes a lot of time to produce the thin film. Further, since such a magnetic head formed in a planar manner must be manufactured by a method of abutting the magnetic heads one by one, productivity is low.

Therefore, as shown in FIG. 12, most of the half-holes 20.20' of the pair of magnetic cores are formed of an oxide magnetic material such as Mn-Zn ferrite, and the magnetic gap forming surface is subjected to vacuum treatment such as sputtering. A magnetic head has been proposed in which a magnetic metal film 21.21' of sendust or the like is formed using thin film fabrication technology, and a pair of core halves thus obtained are bonded with high melting point glass 24.24'. . In this type of magnetic head, since the vicinity of the magnetic gap 25 is composed of a ferromagnetic metal thin film 21, 21' having a high saturation magnetic flux density, it is suitable for magnetic recording media such as metal tapes having high coercive force. Accordingly, it is possible to exhibit sufficient recording and reproducing characteristics. In addition, the sliding surface of the tape is mostly filled with magnetic oxides such as ferrite, which gives it excellent wear resistance.

However, in the magnetic head shown in FIG. 4 described above, since the magnetic metal film 21.21', which is a different material, is formed on the ferrite core material, the boundary 23.23' is a pseudo gap. This has become a major problem, as it acts as a negative influence on electromagnetic conversion characteristics. In particular, this magnetic head is formed by forming a ferromagnetic metal film 21, 21' and then fusion-bonding a pair of magnetic core halves 20, 20' using high melting point glass 24, 24'.
The ferrite and sendust of each of the above-mentioned magnetic materials will be exposed to high temperatures for a long time, causing the boundaries 23.
Diffusion reactions tend to occur at 23'. Therefore, the magnetic discontinuity at this boundary 23, 23' becomes remarkable and acts as a pseudo gap, so-called a contour.
The disadvantage is that noise is likely to occur due to the effect. Here, in order to solve the above-mentioned drawbacks, it has been considered to use so-called low-melting glass to lower the temperature during fusion bonding.

[Problem that the invention seeks to solve]

Low melting point glass has problems in terms of abrasion resistance, water resistance, environmental resistance, etc., and as in this case, a large amount of low melting point glass is exposed on the tape sliding surface, which significantly reduces the reliability of the magnetic head. There's a problem.

As mentioned above, the magnetic head shown in Figure 3, which was proposed as a magnetic head compatible with high coercive force media, has the problem of poor productivity, and a number of methods have been proposed to solve this problem. As shown in FIG. 4, the magnetic head has a problem in that the pseudo-gap effect becomes noticeable due to heat treatment during manufacturing, making it difficult to obtain sufficient recording and reproducing characteristics.

Therefore, the present invention was proposed to solve these problems, and the present invention has been proposed so that the interface between the high magnetic permeability magnetic material and the high saturation magnetic flux density film is parallel to the magnetic gap on the sliding surface of the medium. An object of the present invention is to provide a method for manufacturing a magnetic head that efficiently manufactures a highly reliable magnetic head without the boundary portion acting as a pseudo gap.

[Means for solving problems]

For this purpose, the method for manufacturing a magnetic head according to the present invention includes the steps of forming grooves parallel to each other at a predetermined pitch in one end surface of a block of high magnetic permeability material, and filling the grooves with a first non-magnetic material. a step of polishing the end face until the high magnetic permeability material is exposed after the filling step; a step of depositing a high saturation magnetic flux density film on the surface polished in the polishing step; removing a portion of the deposited high saturation magnetic flux density film that is in contact with the first non-magnetic material; A step of abutting the block with a second non-magnetic material having a lower melting point than the first non-magnetic material so that at least a portion thereof faces each other through a magnetic gap, and cutting the joined block to have a predetermined head width. This includes the process of

[For production]

According to the manufacturing method described above, the block can be manufactured without exposing the block to high temperatures after forming the high saturation magnetic flux density film, and mutual diffusion at the boundary between the high permeability material and the high saturation magnetic flux density material can be suppressed. Furthermore, most of the non-magnetic material exposed on the surface that slides on the magnetic recording medium is a material with a high melting point, ensuring reliability.

〔Example〕

Examples of the present invention will be described below.

First, an embodiment of the method for manufacturing a magnetic head according to the present invention will be described in detail with reference to FIGS. 1(A) to 1(E).

First, as shown in FIG. 1(A), for example, M n −Z
A plurality of track width regulating grooves 2 for regulating the track width are provided in parallel at a predetermined pitch on the upper surface of a substrate l made of a high permeability magnetic oxide such as n-type ferrite.

The track width regulating grooves 2 are formed by a rotary grindstone or the like so that the cross section has a substantially V-shape or a substantially U-shape, respectively, and are arranged at predetermined intervals, a predetermined width, and a predetermined depth over the entire width of the upper surface of the substrate 1. It is formed to be.

Next, as shown in FIG. 1(B), high melting point glass 3 is poured into the track width regulating groove 2 at 600 to 800°C, and the upper surface of the glass is polished until the substrate 1 is exposed. . Then, a magnetic metal thin film 4' having a high saturation magnetic density is formed over the entire surface of the polished substrate by a vacuum thin film forming technique such as sputtering. The material of the magnetic metal thin film 4' is an amorphous alloy or a sendust alloy.

Fe-3i alloy, Fe-Aj! Alloys, Fe-Ni alloys, etc. can be used.

Furthermore, as shown in FIG. 1(C), the magnetic metal thin film 4
A resist is applied to the part corresponding to the track width, that is, a part in contact with the substrate 1, and etched, and the magnetic metal thin film 4' is removed. The metal thin film 4 is left.

Next, as shown in FIG. 1(D), the magnetic metal thin film 4
After pouring low melting point glass 5 over the entire upper surface of the substrate including the upper surface of the substrate to form winding grooves 6, the upper surface is mirror-finished. Note that this surface corresponds to the magnetic gap forming surface. Next, the magnetic metal thin film 4 is subjected to heat treatment to adjust the magnetic properties of the thin film 4.

Here, a core block 7 manufactured by the above-described process and without a winding groove is prepared, and at least one of the magnetic gap forming surfaces of the pair of core blocks is coated with SiO.
A gap spacer made of a non-magnetic material such as □ is formed to a thickness that provides a predetermined gap length.

Next, these pairs of core blocks are arranged so that the respective magnetic metal thin films deposited on the magnetic metal thin film formation surface of the substrate are butted against each other with high precision, and these core blocks are made of low melting point glass. Then, join as shown in FIG. 1(E).

Finally, perform slicing at the position of line A-A' in the figure.
After cutting out a plurality of head chips, the magnetic tape sliding surface is cylindrically polished to complete a magnetic head as shown in FIG. 2.

In the magnetic head manufactured in this manner, pseudo gaps g' and g' at the boundary between the substrate 1 made of a magnetic oxide such as ferrite and the magnetic metal thin film 4 are formed parallel to the main gap g. These pseudo gaps g', g'
The reproduction output of the main gap could be suppressed to 150 dB or less compared to that of the main gap. That is, the magnetic metal thin film 4
After forming the thin film 4, there is no step of exposing the thin film 4 to high temperature, so a pseudo gap g' is created.

Since the diffusion reaction between the magnetic bodies in the vicinity of g' is suppressed, the influence of the pseudo gaps g' and g' can be reduced to a negligible extent, and the result is sufficient for analog recording and reproduction.

Furthermore, since the low melting point glass 5 exposed on the sliding contact surface of the magnetic tape is only as thick as the magnetic metal thin film 4, wear resistance and the like are improved, resulting in excellent reliability.

FIG. 3 is a diagram for explaining a method of manufacturing a magnetic head as another embodiment of the present invention, and FIG. 4 is a diagram showing a magnetic head obtained by this manufacturing method. In the manufacturing method of this embodiment, the grooves 2 formed in the step of FIG. 1(A) are formed only on the side that becomes the medium sliding surface, and the winding grooves 6 are formed first.

Furthermore, due to the polishing in the process shown in FIG. 1(B), the thickness of the substrate 1 on the side of the medium sliding surface from the winding groove 6 is set to a thickness necessary for the high saturation magnetic flux density film 4 compared to the thickness of other parts. Make it as thin as possible. The high saturation magnetic flux density film 4 is also deposited only on the side closer to the medium sliding surface than the winding groove 6. After applying the resist, a part of the high saturation magnetic flux density film 4 is removed by etching, and then a low melting point glass 5 is poured in to obtain a block as shown in FIG. Then, a similar block without winding grooves is joined to the block, cut out into head chips, and the sliding surface is polished to obtain a head core chip as shown in FIG. 4.

The head shown in FIG. 4 also provides the same effect as the head shown in FIG. 2. Further, since the contact area between the ferrite l and the magnetic metal film 4 is small, stress generated inside the ferrite can be reduced, and a decrease in yield due to the occurrence of cracks and the like can be prevented.

FIG. 5 shows the manufacturing process explained using FIG. 3, which includes a polishing process for the medium sliding surface side and a polishing process for the entire surface, in which the winding groove 6 is formed after the magnetic metal film 4 is coated on the entire surface. FIG. 6 shows a magnetic helad core manufactured using this core half block.

Fig. 7 shows a core half block obtained when the groove 2 formed in the step of Fig. 1 (A) is square, and Fig. 8 shows a magnetic herad core manufactured using this core half block. ing.

Figure 9 shows a core half obtained by a manufacturing process in which a shallow 7-shaped groove is formed on the substrate l exposed by polishing after filling with high melting point glass 3 in the process of Figure 1(B). FIG. 10 is a diagram showing a magnetic helad core manufactured using this core half block. In the head core of FIG. 10, the boundary g' between the ferrite l and the magnetic metal film 4 on the medium sliding surface is made non-parallel to the magnetic gap g, so that deterioration of the electromagnetic conversion characteristics due to the contour effect can be further reduced.

It goes without saying that the magnetic heads shown in FIGS. 6, 8, and 10 can provide the same effects as the magnetic head shown in FIG. 2.

〔Effect of the invention〕

As explained above, according to the manufacturing method of the present invention, it is possible to reduce the occurrence of the contour effect due to the existence of the boundary between the high permeability magnetic material and the high saturation magnetic flux density material, and to manufacture a highly reliable magnetic head. be able to.

[Brief explanation of the drawing]

Figures 1 (A) to (E) are diagrams showing a method for manufacturing a magnetic head as an embodiment of the present invention, and Figure 2 is a diagram showing a method for manufacturing a magnetic head as an embodiment of the present invention. A diagram showing a magnetic helad core, FIG. 3 is a diagram for explaining a method of manufacturing a magnetic head as another embodiment of the present invention, and FIG. 4 shows a magnetic helad core obtained by the manufacturing method explained in FIG. 3. FIG. 5 is a diagram for explaining a method of manufacturing a magnetic head as yet another embodiment of the present invention, and FIG. 6 shows a magnetic herad core obtained by the manufacturing method explained in FIG. 5. 7 is a diagram for explaining a method of manufacturing a magnetic head as still another embodiment of the present invention, FIG. 8 is a diagram showing a magnetic herad core obtained by the manufacturing method explained in FIG. 7, 9 is a diagram for explaining a method of manufacturing a magnetic head as still another embodiment of the present invention, FIG. 1O is a diagram showing a magnetic herad core obtained by the manufacturing method explained in FIG. 9, The figure is a perspective view showing an example of a conventional magnetic head.
FIG. 2 is a perspective view showing another example of a conventional magnetic head. In the figure, 1 is a ferrite block as a high magnetic permeability material block, 2 is a track pitch regulating groove, 3 is a high melting point glass as a first non-magnetic material, 4 is a magnetic metal film as a high saturation magnetic flux density film, 5 is a low melting point glass as a second non-magnetic material, 6 is a winding groove, and g is a magnetic gap. Cra! 5 1 Figure (B) 1 Kasumi (D) ? Figure 5

Claims (1)

[Claims] A step of forming mutually parallel grooves at a predetermined pitch on one end surface of a high magnetic permeability material block, a step of filling the grooves with a first non-magnetic material, and a step of filling the end surface with the high magnetic permeability material after the filling step. a step of polishing until exposed, a step of depositing a high saturation magnetic flux density film on the surface polished in the polishing step, and a step of contacting the first non-magnetic material in the deposited high saturation magnetic flux density film. a step of removing a portion of the high saturation magnetic flux density film, and abutting the blocks from which a portion of the high saturation magnetic flux density film has been removed through a magnetic gap such that at least a portion of the high saturation magnetic flux density film faces each other through a magnetic gap; A method for manufacturing a magnetic head, comprising the steps of: joining the blocks with a second non-magnetic material having a lower melting point than the first material; and cutting the joined block to have a predetermined head width.