JP2005141844A - Magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the nonconformity wherein deteriorated production yield or characteristics occurs, such as enlarged bending of a magnetic core half having a metal magnetic film stacked thereon, cracks generated due to peeling from a nonmagnetic substrate or a magnetic gap, or cracks in the mold glass of a winding window part, when a metal magnetic film haivng a easy axis magnetization direction substantially in parallel with a magnetic gap surface within a layer surface is used. <P>SOLUTION: This magnetic head is constructed, in such a manner that magnetic core halves having winding window parts, on which winding coils are wound are arranged with their end surfaces set to face each other to form a magnetic gap; a metal magnetic film and a nonmagnetic film, in which a magnetization easy axis direction is almost in parallel to the magnetic gap surface within a layer surface are stacked alternately by one or more layers; a multilayer metal magnetic film made of a metal magnetic layer, whose partial magnetic easy axis direction is substantially orthogonal to the magnetic gap surface; and an insulating film are alternately stacked to form a metal magnetic layer, thereby constituting a track width. Without arranging any mold glass in the inner surface part of the winding window, the magnetic core halves are bonded together. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a magnetic head suitable for recording and reproducing a high-frequency signal such as a device used in a high-frequency band, for example, a high-definition digital VTR and a data streamer, and a magnetic recording / reproducing apparatus using the magnetic head.

  In recent years, high-capacity and high-definition systems such as high-definition digital VTRs and data streamers have been developed, and magnetic recording media also use conventional iron oxide to record such a large amount of information. The system has changed to a high coercive force medium such as an alloy powder medium or a metal deposition medium. As a magnetic head, it is desired to develop a magnetic head having a high saturation magnetic flux density that can cope with these high coercive force media, narrowing a track with an increase in capacity, and having excellent characteristics in a high frequency band of 40 MHz or more. I came. Therefore, in order to meet such demands, high frequency characteristics are improved by adopting a structure in which both sides of a metal magnetic layer in which a metal magnetic film such as Sendust, amorphous magnetic alloy, FeTaN, etc. and an insulating film are laminated are sandwiched between nonmagnetic substrates. A so-called laminated magnetic head has been developed. However, such a laminated magnetic head has a magnetic path composed only of a metal magnetic film, and high magnetic permeability is required over the entire magnetic path, and it is desirable that the magnetic path be configured only in the hard magnetic axis direction. In order to take all directions in the plane of the metal magnetic film, it is difficult to form a magnetic path only in the direction of the hard axis, and therefore the metal magnetic film is required to be isotropic with small anisotropy. It was. Therefore, the magnetic permeability in the high frequency band of the metal magnetic film is lowered due to natural resonance, and there is a problem that the high frequency characteristics of the magnetic head are deteriorated. Recently, as a method for solving such a problem, a laminated film in which anisotropy is imparted so that the magnetization easy axis directions of adjacent metal magnetic films are almost orthogonal to each other with an insulating film sandwiched therebetween or shifted to an arbitrary angle. Membranes have been proposed. Further, a narrow magnetic gap has been made in order to increase the reproduction efficiency in a high frequency band (see Patent Document 1).

In addition, in order to improve the bonding strength between magnetic core halves laminated with laminated films, the shape of a winding window, molded glass, and the like have been proposed (see Patent Document 2).
JP-A-5-54319 Japanese Patent Laid-Open No. 6-4826

  The problem to be solved is that when a metal magnetic film having an easy axis direction of magnetization that is substantially parallel to the magnetic gap surface and the layer surface is used in a magnetic head having a laminated structure, the stress of the laminated metal magnetic film is also large. Therefore, the warp of the magnetic core half body on which the metal magnetic films are laminated is also increased. By joining such magnetic cores, the residual stress on the metal magnetic film and the residual stress are also applied to the mold glass at the winding window. During the production of the magnetic head having the laminated structure, the pressure when forming the magnetic gap further becomes a residual stress, and the characteristics of the metal magnetic layer are deteriorated. In order to narrow the magnetic gap, the thickness of the material forming the magnetic gap is reduced, and further, the desired magnetic gap is not formed due to the effect of the decrease in bonding strength or residual stress, and sufficient characteristics cannot be obtained. . In addition, the production yield and characteristics are deteriorated, for example, a center crack generated from a nonmagnetic substrate or a magnetic gap, or a crack occurs in the mold glass of the winding window. In the worst case, there were problems such as damage to the tape to be recorded / reproduced by cracking of the magnetic head.

  In the present invention, a magnetic core half having a winding window portion around which a metal magnetic layer is sandwiched between a pair of nonmagnetic substrates and wound by a winding coil is arranged so that the end faces thereof are opposed to each other. A gap is formed, and one or more layers of metal magnetic films and non-magnetic films whose magnetic easy axis directions are substantially parallel to the magnetic gap surface and the layer surface are alternately laminated. In the magnetic head having a track width formed by laminating the metal magnetic layers formed by alternately laminating multilayer metal magnetic films and insulating films formed of metal magnetic films substantially perpendicular to the magnetic gap surface, the winding window portion A magnetic head characterized in that no mold glass is disposed on the inner surface of each of the magnetic core halves and the magnetic core halves are joined together.

  It is possible to increase the adhesive pressure by joining the magnetic core halves in which the multilayer metal magnetic film and the insulating film are alternately laminated without using the mold glass on the inner surface of the winding window of the present invention. Realizing a magnetic gap and reducing the influence of residual stress at the time of joining the magnetic core halves can provide a magnetic head with excellent high-frequency characteristics that does not cause deterioration of magnetic characteristics or separation of the magnetic layer and nonmagnetic substrate. In addition, it is possible to provide a high-productivity magnetic head by improving the deterioration of productivity due to center cracks and mold glass cracks.

  Further, even in a system in which the relative speed of the tape and the head is 20 m / s or higher, a high-definition digital VTR and a large-capacity streamer that can satisfactorily record and reproduce a high-frequency signal of 40 MHz or higher can be realized.

Hereinafter, embodiments of the magnetic head of the present invention will be described in detail with reference to the drawings. Moreover, in each figure, the same code | symbol is attached | subjected to the thing of the same component, and the detailed description is abbreviate | omitted. FIG. 1 is a diagram showing the configuration of a magnetic head according to a first embodiment of the present invention. In FIG. 1, 1 is a metal magnetic layer, which is formed by laminating a metal magnetic film and an insulating film, 2 is a nonmagnetic substrate, 3 is a magnetic gap, 4 is an adhesive layer, and 5 is a winding window. In this embodiment, the metal magnetic film of the metal magnetic layer, which is a magnetic core, is an amorphous magnetic alloy Fe—Ta—N having a high saturation magnetic flux density, and may contain a metal such as Si or Zn. well, it may also be of such CoNbZrTa of Co-based, the insulating film with Si0 ₂ film, the substrate to a Ni-Ti-Ca ceramics nonmagnetic, Ti-Ni-Mg ceramics and non A magnetic single crystal ferrite substrate may be used, and a borosilicate glass is used for the adhesive layer, and the magnetic head structure is a laminated magnetic head having a structure in which both ends of the metal magnetic layer 1 are sandwiched between a pair of substrates 2. is there.

FIG. 2 is a diagram showing the configuration of the metal magnetic layer. 1-a is a metal magnetic film in the direction of easy axis parallel to the magnetic gap surface and the layer surface, 1-b is a metal magnetic film in the direction of easy axis substantially perpendicular to the magnetic gap surface, and 1-c is a nonmagnetic film. FIGS. 3A and 3B, each of which constitutes a laminated metal magnetic layer, are diagrams showing the structure of a magnetic head according to a comparative example of the present invention. 6 is a mold glass disposed in the winding window, and the other configuration is the same as that of the embodiment.

(Embodiment 1)
In Example 1, an Al ₂ O ₃ film having a thickness of 1.0 μm is formed on a Ni—Ti—Ca ceramics substrate by known sputtering, and the easy axis directions of the pair of metal magnetic films are substantially parallel in the magnetic gap plane and the layer plane. Fe-Ta-N, which is a metal magnetic film in which the easy axis direction of magnetization other than the pair of metal magnetic films is substantially perpendicular to the magnetic gap surface, is similarly formed by a known sputtering method to a thickness of 0.395 μm. there Si0 ₂ film 0.005μm deposited metal magnetic film 6 layer forming the multilayered metal magnetic film is an insulating film Si0 ₂ film was 4-layer laminated metal magnetic layer was 0.15μm deposited 9.6μm Prepare a magnetic core half with a track width of. Each magnetic core half was provided with a groove serving as a winding portion, and a magnetic core half was prepared without providing mold glass. The prepared magnetic core halves are arranged so that their end faces face each other, and borosilicate glass and Pyrex (R) glass are used so that the effective GL becomes 0.15 μm, and pressures of 60 kg, 100 kg, and 150 kg are applied. Three types of magnetic heads were produced by forming the film.

(Embodiment 2)
In Example 2, the thickness of the metal magnetic film is about half that of Example 1, and the high frequency characteristics are improved, and the film is produced under the condition that the film residual stress is increased. An Al ₂ O ₃ film having a thickness of 1.0 μm is formed on a Ni—Ti—Ca ceramics substrate by known sputtering, the easy axis directions of the pair of metal magnetic films are substantially parallel in the magnetic gap plane and the layer plane, and the pair the easy magnetization axis direction is 0.195μm deposited by a known sputtering similarly Fe-Ta-N is a metallic magnetic film which is substantially perpendicular to the magnetic gap surface, Si0 ₂ film which is a non-magnetic layer of non-magnetic metal film With a track width of 10.0 μm, four layers of metal magnetic layers formed by depositing 0.15 μm of SiO ₂ film as an insulating film on a multilayer metal magnetic film formed of 12 layers of metal magnetic films formed by 0.005 μm Prepare a configured magnetic core half. Each magnetic core half was provided with a groove serving as a winding portion, and a magnetic core half was prepared without providing mold glass. The prepared magnetic core halves are arranged so that their end faces face each other, and borosilicate glass and Pyrex (R) glass are used so that the effective GL becomes 0.15 μm, and the bonding pressure is 60 kg, 100 kg, 150 kg. To form three types of magnetic heads.

As Comparative Example 1, B ₂ O ₂ —SiO ₂ —Al ₂ O ₃ type mold glass was placed on the winding window of the magnetic core half of Example 1, and the bonding pressure under the same conditions as in Example 1 was applied. Three types of magnetic heads were created. As Comparative Example 2, B ₂ O ₂ —SiO ₂ —Al ₂ 0 ₃ type molded glass of the winding window portion of Example 2 was arranged as in Comparative Example 1, and the rest of the configuration was the same, Comparative Example 2 As a magnetic head.

  The yield in the production process of the magnetic head produced according to the present invention will be described. Examples 1 and 2 and Comparative Examples 1 and 2 of the present invention, each of Example and Comparative Example When 700 magnetic heads were prototyped, the incidence of center cracks in the nonmagnetic substrate and the metal magnetic layer and the yield in the production process The rates are shown in Table 1. Table 2 shows the average value of effective GL.

  As shown in Table 1, Example 1.2 of the present invention is a comparative example in which the production yield such as the occurrence of center cracks, GL defects of magnetic heads, and I, is obtained by bonding without placing mold glass on the winding window. Even when compared with the above, good results were obtained.

  As shown in Table 2, in Example 1.2 of the present invention, the effective GL is 0.15 μm which is the target value by bonding without placing mold glass on the winding window, and compared with the comparative example. Even so, good results were obtained.

  Next, Table 3 shows the results of evaluation of the recording / playback separation / reproduction characteristics of each of the magnetic heads manufactured using a Verdex drum tester. The measurement conditions are v = 20.0 m / s, the tape is MP tape, the recording head is a Matsushita MIG head, and the recording / playback measurement bands are 19.5 MHz, 26 MHz, 40 MHz, and 78 MHz. The reproduction characteristics of Examples 1 and 2 are compared and displayed in dB.

  As shown in Table 3, the results of the examples of the present invention were good in all cases as compared with the conventional examples. From these results, it was confirmed that the magnetic head of the present invention is high in productivity and characteristics and excellent in quality.

  Next, an embodiment of a magnetic recording / reproducing apparatus using the magnetic head of the present invention will be described. In this example, a magnetic recording / reproducing apparatus equipped with the magnetic heads of Examples 1 and 2 of the invention as a recording / reproducing head was prototyped. Even in a system in which the relative speed of the tape and the head is 20 m / s or more, a high-definition digital VTR and a large-capacity streamer that can record and reproduce a high-frequency signal of 40 MHz or more satisfactorily and have stable characteristics and quality can be realized. In particular, it is to stably provide a laminated magnetic head having excellent high frequency characteristics.

  The magnetic head according to the present invention increases the adhesion pressure by bonding the magnetic core halves in which the multilayer metal magnetic films and the insulating films are alternately laminated without arranging the mold glass on the inner surface of the winding window. Magnetic head with excellent high-frequency characteristics that can reduce the effect of residual stress when joining magnetic core halves and reduce magnetic characteristics and prevent separation of the magnetic layer and nonmagnetic substrate. Can provide. In addition, it is possible to provide a high-productivity magnetic head by improving the deterioration of productivity due to center cracks and mold glass cracks.

  Further, even in a system in which the relative speed of the tape and the head is 20 m / s or more, it can be applied to uses such as a high-vision digital VTR and a large-capacity streamer that can satisfactorily record and reproduce a high-frequency signal of 40 MHz or more.

The figure which shows the structure of the magnetic core of 1st Example of the magnetic head of this invention. One layer enlarged view of the metal magnetic layer of the first embodiment of the magnetic head of the present invention. The figure which shows the structure of the magnetic core of the comparative example of the magnetic head of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal magnetic layer 1-a Metal magnetic film of the easy axis direction parallel to the magnetic gap surface in the layer surface 1-b Metal magnetic film of the easy axis direction almost orthogonal to the magnetic gap surface 1-c Nonmagnetic film 2 Non Magnetic substrate 3 Magnetic gap 4 Adhesive layer 5 Winding window 6 Mold glass

Claims (1)

A magnetic magnetic layer is sandwiched between a pair of nonmagnetic substrates, and a magnetic core half having a winding window around which a winding coil is wound is disposed so that the end faces face each other to form a magnetic gap. One or more layers of metal magnetic films and nonmagnetic films whose magnetic easy axis directions are substantially parallel to the magnetic gap surface and the layer surface are alternately laminated, and the magnetic easy axis direction of a part of the metal magnetic film is the magnetic gap surface. In a magnetic head having a track width configured by laminating the metal magnetic layers formed by alternately laminating multilayer metal magnetic films and insulating films formed of substantially perpendicular metal magnetic films, the inner surface of the winding window portion A magnetic head characterized in that magnetic core halves are joined to each other without molding glass.

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