JPH087217A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To provide a sandwich type magnetic head which has high processing precision to cope with narrowed track width, causes no uneven wear and to provide its production method. CONSTITUTION:This magnetic head is constituted as that a magnetic layer 11 is interposed between nonmagnetic plates 1 each having a projected part 10 on both sides in the track width direction on the area where a magnetic gap is formed. The head is produced by forming the projected part 10 by etching at least one surface of a nonmagnetic plate l, forming a magnetic layer 11 and joining layer 13 on the surface where the projected part 10 is formed to obtain a substrate, and then joining these substrates 12a, 12b with the projected part 10 facing each other. Thus, a magnetic core substrate 14 is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a magnetic recording apparatus, and more particularly to a magnetic head having a thin magnetic core sandwiched between nonmagnetic plates (hereinafter referred to as a sandwich type magnetic head).

[0002]

2. Description of the Related Art With the increase in density of magnetic recording, magnetic heads having a magnetic core of a magnetic metal having a high saturation magnetic flux density such as sendust, amorphous, and permalloy, have been widely used recently. A so-called bulk type magnetic head using such a metal magnetic material as a magnetic core has a magnetic core having a high saturation magnetic flux density, and therefore, in terms of magnetic characteristics, the magnetic core has a magnetic field density higher than that of an oxide magnetic material such as ferrite. Although it can be made extremely thin, abrasion resistance and mechanical strength are required due to sliding characteristics with respect to the recording medium, and therefore, it is disclosed in JP-A-63-48606.
A sandwich type magnetic head as disclosed in Japanese Patent Publication is generally used. A method of manufacturing this sandwich type magnetic head will be described with reference to the drawings. As shown in FIG. 6a, a magnetic layer 2 made of sendust or the like as a metallic magnetic material having a high saturation magnetic flux density is formed on one surface of the non-magnetic plate 1 by a method such as sputtering.
Further, a glass layer serving as the bonding layer 3 is formed on at least one of the nonmagnetic plates 1 by the same method. As shown in FIG. 6b, the two non-magnetic plates 1 are laminated and heated with their thin film forming surfaces facing each other, and the glass of the bonding layer 3 is melted and integrated to form a magnetic core substrate 4. Next, the magnetic core substrate 4 is cut along a plane orthogonal to the stacking direction to form a magnetic core half body 7, as shown by a dotted line in FIG. 6B. And
As shown in FIG. 6c, track width regulating grooves 6a and 6b are formed on the cut separation surface of the magnetic core half body 7 by cutting so as to form a track width smaller than the thickness of the winding groove 5 and the magnetic core. Form. As shown in FIG. 7, the magnetic core halves 7 and 7 are made to face the winding groove 5, and the glass 8 embedded in the track width regulating grooves 6a and 6b is melted, and a gap spacer (not shown) is used. The magnetic gap G is formed and integrated to form the magnetic core chip 9. And
A conductive wire (not shown) is wound through the winding groove 5 formed in the magnetic core chip 9 to complete the sandwich type magnetic head.

[0003]

Recently, as the density of magnetic recording has further increased and the width of the recording track has been narrowed down to a few microns, the requirement for the processing accuracy of the track width regulating groove becomes strict, and the step during processing becomes difficult. As the retention decreases, the glass for bonding, which is embedded in the track width regulation groove and has low wear resistance, is exposed at the sliding contact surface with the recording medium. In particular, there has been a problem that the glass portion is greatly worn and uneven wear is caused to cause a problem in sliding contact with the recording medium. The present invention proposes to solve the above-mentioned conventional problems, and provides a sandwich-type magnetic head suitable for high-precision processing corresponding to the narrowing of the track width and free from uneven wear. To aim.

[0004]

A magnetic head is characterized in that a magnetic layer (11) is sandwiched between non-magnetic plates (1) having protrusions (10) on both sides of a magnetic gap (G) forming portion in the track width direction. According to the manufacturing method, at least one surface of the non-magnetic material plate 1 is etched to form the convex portion 10, and the magnetic material layer 11 is formed on the convex portion forming surface including the convex portion 10 of the non-magnetic material plate 1.
To form a substrate 12, the substrate 12 is flattened, the two convex portions 10 of the two substrates 12 are opposed to each other, and the magnetic core substrate 14 is formed by joining and joining the magnetic core substrate 14. In, the magnetic core substrate 14 is cut and separated at a plane orthogonal to the joint surface to form a magnetic core half body 15. The magnetic core half body 15 is made to face the cut surface, and the magnetic core half body 15 is integrally bonded via a gap spacer. It is characterized in that a magnetic core chip 16 produced by converting the magnetic core chip 16 into a chip is used. In order to realize a narrow track magnetic head with improved magnetic recording characteristics on a high coercive force medium for high density recording, it is desirable that the magnetic layer 11 be made of FeTaN alloy.

[0005]

According to the structure of the present invention, the track width is regulated by the thickness of the magnetic layer 11 formed on the surface of the non-magnetic plate 1 on which the protrusion 10 is formed, even if the track width is very narrow, such as several microns. However, since the thickness of the magnetic layer 11 can be processed by plane polishing in units of submicrons, the processing accuracy of the track width can be increased. Further, the sliding contact surface with the recording medium is formed only by the magnetic layer 11 and the non-magnetic plate 1 having high abrasion resistance, and the glass is not exposed. No wear occurs. If FeTaN alloy is used for the magnetic layer 11, magnetic recording characteristics and abrasion resistance are improved, so that magnetic recording / reproduction can be performed on a high coercive force medium with a narrow track of several microns, and the abrasion resistance is also improved. It is possible to provide a sandwich type magnetic head having improved

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In the figure, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted. The magnetic head of the present invention is characterized in that the track width is regulated by the convex portion 10 formed on the non-magnetic plate 1. Hereinafter, the method for manufacturing the magnetic head of the present invention will be described in detail. As shown in FIG. 1, a convex portion 10 having a height h = (Tc-Tt) / 2 obtained from the thickness Tc of the magnetic core and the track width Tt is formed on one surface of the non-magnetic plate 1 by etching. As the magnetic layer 11, a thin film of FeTaN alloy, for example, is formed on the surface where the convex portion 10 is formed by sputtering to be slightly thicker than the thickness Tc / 2 which is half the thickness of the magnetic core. As shown in FIG. 2A, the magnetic layer 11 forming surface has a thickness Tc which is half the thickness of the magnetic core.
The first substrate 12a is ground so that it becomes 1/2.
To form. Further, as shown in FIG. 2B, a second substrate 12b having a very thin glass layer as a bonding layer 13 is formed on the flattened magnetic layer 11. As shown in FIG. 3, the first substrate 12a and the second substrate 12b are superposed on each other on the surface where the magnetic layer 11 and the bonding layer 13 are formed, and the glass of the bonding layer 13 is heated and melted to integrally bond them. To form the magnetic core substrate 14. Then, the magnetic core substrate 14 is cut at approximately the central portion of the convex portion 10 formed on the non-magnetic plate 1 as indicated by the dotted line on the plane orthogonal to the bonding surface, and the magnetic core half body 15 is obtained. As shown in FIG. 4, a winding groove 5 is formed on at least one cut surface of the magnetic core half body 15 in the same manner as in the conventional example, and a gap is formed by the bonding glass 8 embedded in the winding groove 5. The magnetic core chip 16 having the magnetic gap G formed by joining and integrating via a spacer (not shown) is obtained.
A magnetic wire of the present invention is completed by winding a conductive wire (not shown) in the winding groove 5 formed in the above. As described above, in the sandwich type magnetic head manufactured in this way, the track width Tt is formed not by cutting but by plane polishing capable of high precision processing, so that the processing precision is improved to the submicron unit. For example, even a magnetic head having a track width Tt of several microns can be sufficiently mass-produced. Further, since the glass 8 for bonding, which has low abrasion resistance, is not exposed on the sliding contact surface with the recording medium, uneven wear does not occur. Furthermore, FeT is added to the magnetic layer.
Since the aN alloy is used, it is possible to provide a sandwich type magnetic head having excellent magnetic recording / reproducing characteristics and high abrasion resistance for a high coercive force medium even in a narrow track. The example in which the bonding layer 13 is formed only on the second substrate 12b for forming the magnetic core substrate 14 has been described above, but the present invention is not limited to this, and a thinner bonding layer 13 is formed on the first substrate 12a. The same processing can be performed by forming and joining the two first substrates 12a. As described above, by using one type of board, there is an effect that component management becomes easy. Also, as the magnetic layer 11, an example in which a thin film of FeTaN alloy is formed has been described.
A magnetic material having a high magnetic flux saturation density such as sendust, amorphous and permalloy can also be used as the material. In addition, the above is for simplicity of explanation,
Although the description has been made focusing on a single sandwich type magnetic head, in general, as shown in FIGS. 5A to 5C, the convex portions 10 and 10 are formed on both surfaces of the non-magnetic plate 17, and the convex portion 1 is formed.
A substrate 18 in which the magnetic layers 11 and 11 are respectively formed on the 0 formation surface is prepared (FIG. 5 a), and a plurality of the substrates 18 are laminated to form a magnetic core substrate block 19 (FIG. 5 a).
b), the magnetic core substrate block 19 is cut along a plane orthogonal to the stacking plane, as shown by a dotted line, in a substantially central portion of the convex portion 10 to form a magnetic core half block 20. The winding groove 5 is formed in the half block 20 to form the magnetic core block 21 integrally joined by the glass 8 for joining (FIG. 5c), and the non-magnetic plate 17 is attached to the half block 20 of FIG.
As shown by the dotted line in FIG.
A manufacturing method by block processing suitable for mass production is adopted.

[0007]

According to the present invention, since the sliding contact surface with the recording medium is formed only by the magnetic layer and the non-magnetic plate having high abrasion resistance, uneven abrasion does not occur. Further, since the track width corresponds to the thickness of the magnetic layer formed on the convex forming surface formed on the non-magnetic plate, the width accuracy can be increased. When the FeTaN alloy is used for the magnetic layer, the magnetic characteristics and abrasion resistance are improved, so that it is possible to provide a sandwich type magnetic head capable of sufficient magnetic recording and reproduction even in a narrow track and having a long life.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing formation of a magnetic layer according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view of an essential part of a first substrate according to an embodiment of the present invention. FIG. 2B is a cross-sectional view of an essential part of a second substrate according to an embodiment of the present invention.

FIG. 3 is a side view of a main part of a magnetic core substrate according to an embodiment of the present invention.

FIG. 4 is a perspective view of a magnetic core chip according to an embodiment of the present invention.

5A and 5B are side views of a main part of a magnetic core substrate according to another embodiment of the present invention, and FIG. 5C is a perspective view of a magnetic core block according to another embodiment of the present invention.

FIG. 6A is a cross-sectional view of an essential part showing formation of a conventional magnetic layer, FIG. 6B is a side view of an essential part of a conventional magnetic core substrate, and FIG. 6C is a perspective view of a conventional magnetic core half body.

FIG. 7 is a perspective view of a conventional magnetic core chip.

[Explanation of symbols]

 1 Non-Magnetic Plate 10 Convex Part 11 Magnetic Layer 12a First Substrate 12b Second Substrate 13 Bonding Layer 14 Magnetic Core Substrate 15 Magnetic Core Half Tt Track Width Tc Magnetic Core Thickness h Convex Height G magnetic gap

Claims (3)

[Claims] 1. A magnetic head having a structure in which magnetic core halves each having a magnetic layer serving as a magnetic core sandwiched between nonmagnetic plates are butted against each other through a gap spacer to form a magnetic gap. The magnetic layer of the formation portion,
A magnetic head characterized in that the magnetic head is sandwiched by convex portions formed on the non-magnetic plate. 2. The magnetic head according to claim 1, wherein the magnetic layer is an alloy layer made of FeTaN. 3. A step of etching at least one surface of a non-magnetic material plate to form a projection, a step of forming a magnetic material layer on the surface of the non-magnetic material plate on which the projection is formed, and a step of forming the magnetic material layer. A step of polishing the surface and flattening to form a substrate; a step of forming a magnetic core substrate by joining and integrating two said substrates with their convex portions facing each other; Forming a magnetic core chip by cutting and separating the magnetic core substrate at a plane orthogonal to the bonding surface to form a magnetic core half body; A method of manufacturing a magnetic head, comprising: