JP2000149213A - Manufacture of magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the variance in the dimension of thickness in each part of a block at the time of facing processing of the side surfaces of a facing block in a manufacturing process of magnetic head. SOLUTION: In this manufacturing method, film forming substrates 22 wherein a metallic magnetic film 21 is formed onto a non-magnetic card material substrate 20 are made, and plural film forming substrates 22 are laminated with an azimuth angle θ and joined to form a joined slice 23. And the joined slice 23 is cut, a facing block 26 is cut out, and mirror polishing is applied to side surfaces 24a and 25a of the facing block 26 using a both-side lapping machine. Thereafter, the facing block 26 is cut into pieces to form magnetic core half body blocks 24, 25, and flattening is applied to a gap forming surface 30 using the side surfaces 24a, 25a as a reference to form a winding wire groove 8. Thereafter, mirror polishing is applied to the gap forming surface 30, and the magnetic core half body blocks 24, 25 are mutually butted and integrated in a state that a magnetic gap (g) is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head useful in a high-density recording / reproducing apparatus such as a video tape recorder (VTR) or a digital audio tape recorder (R-DAT). .

[0002]

2. Description of the Related Art Conventionally, in magnetic recording / reproducing devices such as video tape recorders and digital audio tape recorders, recording of short-wavelength information signals has been promoted for the purpose of improving image quality and the like. High coercive force magnetic recording media such as so-called metal tapes using ferromagnetic metal powders as magnetic powders and vapor-deposited tapes on which a ferromagnetic metal material is directly applied on a base film have been used. I have.

On the other hand, research has been conducted in the field of magnetic heads to cope with this, and in order to enable recording and reproduction on a high coercive force magnetic recording medium, a metal magnetic material is used for a core material and a narrow magnetic material is used. Track-oriented magnetic heads have been developed. As such a magnetic head,
The magnetic core halves sandwiching a metal magnetic film with high magnetic permeability and high saturation magnetic flux density are abutted to each other by a substrate made of non-magnetic material (non-magnetic guard material), joined together by glass fusion, and integrated. A so-called laminated type magnetic head is known.

FIG. 12 is a perspective view showing an example of such a magnetic head. In this type of magnetic head,
The magnetic core includes a pair of magnetic core halves 10 forming a closed magnetic circuit.
1 and 102 are butted and joined together to form a magnetic gap g on the sliding surface 103 with the magnetic recording medium. The magnetic core halves 101 and 102 are made of non-magnetic guard members 111, 112, 113 and 114 and a metal magnetic film 10.
6, 107, and the metal magnetic films 106, 107
It is sandwiched between non-magnetic guard members 111, 112, 113, 114.

[0005] At the abutting surfaces of the magnetic core halves 101 and 102, the ends of the metal magnetic films 106 and 107 abut to form a magnetic gap g. Track width Tw of the magnetic gap g
Since the guard members 111, 112, 113, and 114 are non-magnetic, they are regulated by the thicknesses of the metal magnetic films 106 and 107. The magnetic core half 10
A winding window 108 for restricting the depth Dp (depth) of the magnetic gap g and winding the coil is formed on the abutting surfaces of the first and second mating surfaces 102.

In the above magnetic head, the metal magnetic film 1
06 and 107, ie, the track width Tw of the magnetic gap g.
By controlling the film thicknesses of the layers 6 and 107, there are various advantages such as easy track narrowing, no generation of a pseudo gap in structure, and simplification of the manufacturing process. As a method for manufacturing such a magnetic head, first, a metal magnetic film for forming a magnetic core half and a non-magnetic guard material are laminated in a multilayer shape with a fixed azimuth angle to form a surface setting block. Then, the side surfaces of the surfacing block are polished by polishing to surfacing the side surfaces of the magnetic core half.

After the surfacing step, the halves are divided into a pair of half-blocks with a cross-section set substantially at the center between the flared side surfaces, and the half-blocks are plane-processed. A magnetic gap forming surface and a winding window are formed on the processed surface. Further, after the formation of the magnetic gap forming surface and the winding window portion, each half block is abutted and joined to form a magnetic core block having a magnetic gap, and the end face of the magnetic core block facing the magnetic gap is polished. At the same time, the nonmagnetic guard layer of the magnetic core block is cut in the plane direction to form a magnetic head.

[0008]

However, in the method of manufacturing a magnetic head of the type described above, there has conventionally been a problem that track deviation occurs due to the thickness accuracy of the side-projecting block before gap formation. This is caused by a variation in the thickness dimension due to an inclination error of the side surface after the surface processing of the side surface of the surface-appearing block, that is, a deterioration in the thickness accuracy of the block. In other words, when machining the gap forming surface, since the exposed side surface of the half block is used as a reference, if the thickness of each part of the block after the facing process is different, the gap forming surface to be performed after the block is cut off. An error occurs in each part of the half block due to the machining allowance. As a result, the pitch between the magnetic films differs between the half blocks, and a track shift occurs.

Accordingly, an object of the present invention is to provide a method of manufacturing a magnetic head capable of suppressing variations in the thickness of each part of a block and preventing a track shift when the side surface of the block is exposed. Is to do.

[0010]

According to the present invention, in order to achieve the above object, a pair of magnetic core halves formed by sandwiching a metal magnetic film for forming a closed magnetic path from both surfaces thereof with a non-magnetic guard material are provided. A method for manufacturing a magnetic head in which end faces of the metal magnetic film are joined to face each other, and a magnetic gap is formed between abutting surfaces thereof, wherein the metal magnetic film for forming the magnetic core half is non-conductive. A magnetic guard material is laminated in a multilayer with a certain azimuth angle to form a surface-appearing block, and the side surface along the laminating direction of the surface-appearing block is polished by polishing, and the side surface of the magnetic core half is polished. Having a step of surfacing, in the surfacing step,
By using a double-side polishing machine, both side surfaces of the surfacing block are simultaneously polished.

In the method of manufacturing a magnetic head according to the present invention, a metal magnetic film for forming a magnetic core half and a non-magnetic guard material are laminated in a multilayer shape with a fixed azimuth angle to form a surface-appearing block. Then, the side surface along the laminating direction of the surfacing block is polished by polishing to surfacing the side surface of the magnetic core half. Then, in the step of polishing the side surface of the surface-appearing block by polishing, both side surfaces of the surface-appearing block are simultaneously polished by using a double-side polishing machine. By doing this, by simultaneously polishing both sides, which was conventionally performed one by one,
Polishing can be performed in a state where the parallelism of both side surfaces is maintained with high precision, and variations in the thickness dimension of each part of the block can be suppressed.

[0012] After the surfacing step, the halves are divided into a pair of half-blocks with a cross-section set substantially at the center between the flared side surfaces, and the half-blocks are plane-processed. A magnetic gap forming surface and a winding window are formed on the processed surface. Further, after the formation of the magnetic gap forming surface and the winding window portion, each half block is abutted and joined to form a magnetic core block having a magnetic gap, and the end face of the magnetic core block facing the magnetic gap is polished. At the same time, the nonmagnetic guard layer of the magnetic core block is cut in the plane direction to form a magnetic head.

As described above, the magnetic head manufacturing method according to the present invention is different from the conventional method in that both sides are polished when the block side surface is exposed. That is, in the conventional manufacturing method, the side surface of the block is processed one by one, but in the present invention, by processing both sides simultaneously, it is possible to reduce the variation in the thickness of each part of the block. And As a result, variations in track dimensions, that is, variations in characteristics due to track deviation are reduced, and the yield can be improved. In this method of manufacturing a laminated magnetic head, by performing double-side polishing by double-side polishing, it is not necessary to attach a block to a jig or the like at the time of polishing on each side unlike the conventional method. Can be processed without being affected by the Furthermore, by using a double-side polishing machine, it is possible to reduce not only the thickness variation in one block but also the thickness variation between different blocks.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a magnetic head according to the present invention will be described below. FIG. 1 is a perspective view showing an example of a magnetic head manufactured by the magnetic head manufacturing method according to the present invention. In this type of magnetic head, the magnetic core has a pair of magnetic core halves 1 and 2 constituting a closed magnetic path, butted and joined together, and a magnetic surface is provided on a sliding surface 3 with a magnetic recording medium (not shown). A gap g is formed.

The magnetic core halves 1 and 2 are composed of non-magnetic guard members 11, 12, 13, and 14 and metal magnetic films 6 and 7. 1
2, 13, and 14. The non-magnetic guard members 11, 12, 13, 14 are not particularly limited as long as they are non-magnetic, have an appropriate coefficient of thermal expansion, and have abrasion resistance to a magnetic tape. For example, nonmagnetic ferrite, zirconium oxide-based ceramic, crystallized glass, nonmagnetic iron oxide-based ceramic, titanate-based ceramic, or the like, or a bonding material thereof is used.

For the metal magnetic films 6 and 7, besides various ferromagnetic materials, for example, ferromagnetic alloy materials having a high saturation magnetic flux density and excellent soft magnetic properties are used. Any known material can be used, and it does not matter whether it is crystalline or amorphous. To illustrate,
Fe-Al-Si based alloy, Fe-Si-Co based alloy, F
e-Ni alloy, Fe-Al-Ge alloy, Fe-Ga
-Ge alloy, Fe-Si-Ge alloy, Fe-Si-
Ga-based alloy, Fe-Si-Ga-Ru-based alloy, Fe-C
An o-Si-Al-based alloy or the like can be used. Furthermore, in order to further improve corrosion resistance, wear resistance, etc., Ti, C
r, Mn, Zr, Nb, Mo, Ta, W, Ru, Os,
At least one of Rh, Ir, Re, Ni, Pd, Pt, Hf, and V may be added.

Further, a ferromagnetic amorphous metal alloy, a so-called amorphous alloy (for example, an alloy composed of one or more elements of Fe, Ni, Co and one or more elements of P, C, B, Si, Or Al, Ge, B
e, Sn, In, Mo, W, Ti, Mn, Cr, Zr,
Metal-metalloid amorphous alloys such as alloys containing Hf and Nb, and metal-metal based amorphous alloys mainly containing transition elements such as Co, Hf and Zr, and rare earth elements). These metal magnetic films 6,
As the film forming method 7, a vacuum thin film forming technique typified by a sputtering method, a vacuum deposition method, an ion plating method, an ion beam method, or the like, which is excellent in controlling the film thickness, is employed. In addition, the metal magnetic films 6 and 7 formed on the substrate are not limited to a single layer, and in order to avoid an eddy current loss in a high frequency band, a metal magnetic film and an insulating layer are alternately laminated in multiple layers. A so-called laminated film may be used.

At the abutting surfaces of the magnetic core halves 1, 2, the ends of the metal magnetic films 6, 7 abut to form a magnetic gap g. The track width Tw of the magnetic gap g is equal to the guard material 1.
Since 1, 12, 13, and 14 are nonmagnetic, they are regulated by the thickness of the metal magnetic films 6 and 7. In addition, a winding window 8 for restricting the depth Dp (depth) of the magnetic gap g and winding a coil is formed on the abutting surfaces of the magnetic core halves 1 and 2. That is, the winding window 8 is formed as a rectangular hole in the middle of the abutting surface of the one magnetic core half 1 so as to penetrate in the thickness direction of the magnetic head.

In the above magnetic head, the thickness of the metal magnetic films 6 and 7 is equal to the track width T of the magnetic gap g.
w, the track can be easily narrowed by controlling the thickness of the metal magnetic films 6 and 7;
In addition, there are various advantages such as that no pseudo gap is generated in the structure and that the manufacturing process is simple.

Next, a method of manufacturing the above-described magnetic head will be described. In general, magnetic heads have a type in which grooves for winding windows are provided in both magnetic core halves (both windows).
And a type in which a groove for a winding window is provided only on one side (single window). The present invention can be manufactured in either type, but the one-window type can be manufactured relatively easily. In this example, an example of a single window type will be described. First, a strip-shaped non-magnetic guard material substrate 20 as shown in FIG.
Next, a film forming substrate 22 in which the metal magnetic film 21 is formed to a predetermined thickness by a sputtering method or the like is formed. Next, as shown in FIG. 3, a plurality of film-forming substrates 22 are laminated and bonded at an azimuth angle θ to form a bonded slice 23. Next, FIG.
Then, the joint slice 23 is cut. At that time, FIG.
As shown in (1), the magnetic core half blocks 24 and 25 are cut out in a state of a side surface facing block 26 integrated therewith.

Next, as shown in FIG. 6, the side surfaces 24a and 25a of the side surface facing block 26 are subjected to mirror polishing using a double-sided lapping machine. Block 26 generated at that time
The difference between the maximum value T1 and the minimum value T2 of the thickness of each part of
Thickness variation. In an actual prototype, the thickness of a block was measured at six points in one block, and the M
When ax-Min = variation, in conventional single-side processing, the average: 2.0 μm, the maximum: 3.0 μm, and the minimum: 0.
In contrast to 7 μm, in the process using double-side polishing,
Average: 0.2 μm, maximum: 0.3 μm, minimum: 0.1 μm
m and thickness variation became 1/10 or less. As a material of a surface plate used for double-sided polishing, a soft metal for lapping / polishing (for example, Cu, Sn, Al, Pb, or an alloy containing them) is used. Natural, artificial and the like).

Next, as shown in FIG. 7, the surfacing block 26 is divided into magnetic core half blocks 24 and 25. Thereafter, the gap forming surface 30 is flattened with reference to the side surfaces 24a and 25a. At that time, the machining allowance 40 of the magnetic core half blocks 24 and 25 changes depending on the thickness variation T1-T2. The change in the pitch between magnetic films L
1, L2 also changes relatively. As a result L
The difference between 1 and L2 is a track shift. Next, as shown in FIG. 8, a winding groove 8 for winding a coil is formed on the gap forming surface 30 of each of the magnetic core half blocks 24 and 25 in the entire stacking direction of one magnetic core half block 24. It is formed over. Thereafter, the gap forming surface 30 is subjected to mirror polishing.

Next, as shown in FIG. 9, the magnetic core half blocks 24 and 25 are abutted. When the magnetic core half blocks 24 and 25 are abutted, the respective metal magnetic films 6 and 7 are aligned and bonded and integrated via a gap material. As a result, a magnetic gap g is formed between the butted metal magnetic films 6 and 7. Then
As shown in FIG. 10, the magnetic core block 27 thus formed is subjected to cylindrical polishing for ensuring contact with the magnetic recording medium. Finally, as shown in FIG. 11, when the width restricting groove 10 is inserted into the magnetic core block 27 and cut, the magnetic head of the present example shown in FIG. 1 is completed. Here, a conventionally known bonding method can be used for bonding the members, and for example, low-temperature diffusion bonding (a method in which the noble metal layers provided on the bonding surface are bonded by thermal diffusion).
And bonding with bonding glass or the like.

The multilayer magnetic head manufactured by the above-described manufacturing method can reduce the variation in thickness at each part of the block after the block side surface is exposed, as compared with the multilayer magnetic head manufactured by the conventional method. For this reason,
Variations in characteristics due to variations in track dimensions and deviations of the trunk can be reduced, and the yield can be improved.

[0025]

As described above, in the method of manufacturing a magnetic head according to the present invention, a side surface along a laminating direction of a surface-appearing block in which a metal magnetic film and a non-magnetic guard material are laminated is polished by a polishing process. In the step of exposing the side surface of the half body, both side surfaces of the exposing block were simultaneously polished by using a double-side polishing machine. For this reason, it is possible to suppress variations in the thickness dimension of each part of the surfacing block, prevent track deviation, easily provide a high-quality magnetic head, and improve the yield.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a magnetic head to which the present invention is applied.

FIG. 2 is a conceptual diagram showing a step of forming a metal magnetic film on a non-magnetic guard material substrate in the method of manufacturing the magnetic head shown in FIG.

FIG. 3 is a conceptual diagram showing a bonding step of a film formation substrate in the method of manufacturing the magnetic head shown in FIG.

FIG. 4 is a conceptual diagram showing a cutting step of a joining slice in the method of manufacturing the magnetic head shown in FIG.

FIG. 5 is a conceptual diagram showing a surface-appearing block cut out from a joining slice in the method of manufacturing the magnetic head shown in FIG.

FIG. 6 is a conceptual diagram showing a step of performing side surface surfacing processing on a surfacing block in the method of manufacturing the magnetic head shown in FIG. 1;

FIG. 7 is a conceptual diagram showing a step of dividing a surface forming block and performing a polishing process on a gap forming surface in the method of manufacturing the magnetic head shown in FIG. 1;

FIG. 8 is a conceptual diagram showing a step of subjecting a gap forming surface of a magnetic core half block to a winding groove and mirror polishing in the method of manufacturing the magnetic head shown in FIG. 1;

FIG. 9 is a conceptual diagram showing a step of abutting magnetic core half blocks in the method of manufacturing the magnetic head shown in FIG. 1;

FIG. 10 illustrates a method of manufacturing the magnetic head shown in FIG.
It is a conceptual diagram which shows the cylindrical grinding process of a magnetic core block.

FIG. 11 is a cross sectional view showing a method of manufacturing the magnetic head shown in FIG. 1;
It is a conceptual diagram which shows the process of making a width | variety restricting groove | channel in a magnetic core block, and cutting | disconnecting for every magnetic head.

FIG. 12 is a perspective view showing an example of a conventional magnetic head.

[Explanation of symbols]

1, 2... Magnetic core half, 3... Sliding surface, 6, 7, 21
... Metal magnetic film, 11, 12, 13, 14... Non-magnetic guard material, 8... Winding window, 20.
22: film-forming substrate, 23: bonding slice, 24, 25
... Half magnetic core block, 24a, 25a...
... gap forming surface, 40 ... processing allowance.

Claims (5)

[Claims] 1. A pair of magnetic core halves formed by sandwiching a metal magnetic film for forming a closed magnetic circuit from both surfaces thereof with a non-magnetic guard material, and joined together by opposing end surfaces of the metal magnetic film. A method of manufacturing a magnetic head in which a magnetic gap is formed between the butted surfaces, wherein a metal magnetic film and a non-magnetic guard material for forming the magnetic core half are formed into a multilayer with a constant azimuth angle. Laminating to form a surfacing block, polishing the side surface along the laminating direction of the surfacing block by polishing, and performing surfacing of the side surface of the magnetic core half; 3. The method for manufacturing a magnetic head according to claim 1, wherein both side surfaces of the surfacing block are simultaneously polished by using a double-side polishing machine. 2. The surfacing block, after the surfacing process, is divided into a pair of half-blocks at a division plane set substantially at the center between the exposed side surfaces, and each half-block is divided into two. 2. The method of manufacturing a magnetic head according to claim 1, further comprising: flattening the divided section with reference to the exposed side surface; and forming a magnetic gap forming surface and a winding window on the processed surface. 3. After the formation of the magnetic gap forming surface and the winding window, each half block is abutted and joined to form a magnetic core block having a magnetic gap, and the magnetic gap of the magnetic core block is reduced. 3. The magnetic head manufacturing method according to claim 2, wherein the magnetic head is formed by polishing the facing end surface and cutting the non-magnetic guard material layer of the magnetic core block in the surface direction. 4. The method according to claim 1, wherein the surface plate used in the double-side polishing machine is made of a soft metal. 5. The method of manufacturing a magnetic head according to claim 1, wherein the abrasive grains contained in the working fluid used in the double-side polishing machine are diamond, and the abrasive grain diameter is 2 μm or less.