JPS6238518A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To eliminate dummy gaps to improve the efficiency by stepping the apex part of the magnetic film part of a C type core, which should be provided with a winding, in parallel with a gap part and eliminating the curvature part of the apex part. CONSTITUTION:Metallic magnetic films 2 and 2' and an insulating layer 7 are laminated on an Mn-Zn ferrite 1 alternately. A nonmagnetic insulating material like Ti, an Al2O3, or an SiO2 is sputtered to form the insulating layer. The magnetic film 2 is stepped in parallel with the gap, and the curvature part of the apex part is sufficiently eliminated up to such area that the apex of a substrate is not parallel with the gap in the gap depth setting work. By eliminating the magnetic film part, the gap part, the substrate, and magnetic films cross obliquely practically even after the gap depth setting work. Since the magnetic flux leaked from the apex part for recording is reduced and a sharp magnetic field is easily generated in the head front end part by the stepping effect, dummy gaps disappear in the head.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head suitable for recording and reproducing high frequency signals in disk files and the like. In particular, the present invention relates to a composite magnetic head suitable for high coercivity media in which a plurality of magnetic films are laminated on a substrate with an insulating layer interposed therebetween.

[Conventional technology]

In high-density magnetic recording and reproducing devices, it is well known that increasing the coercive force Hc of the magnetic recording medium is advantageous for high-density recording. A large shallow magnetic field is required. However, the ferrite materials used in current magnetic heads are
Since the saturation magnetic flux density B is about 3,800 to 5.200 G, there is a limit to the strength of the recording magnetic field that can be obtained, and the coercive force Hc of the magnetic recording medium is about 10,000. On the other hand, if F6→Z-S, which is well known as a metal magnetic material, is used as a crystalline alloy such as alloy (sendust), Ni-Fe alloy (permalloy), or non- Magnetic heads using crystalline alloys generally have superior properties such as higher saturation magnetic flux density and lower sliding noise than ferrite.However, when these metallic magnetic materials are used in bulk materials, they suffer from eddy current loss. Yoshi number MH
It has the disadvantage that the frequency characteristics in the high frequency region of z are lower than that of ferrite, and the reproduction output is lower. Therefore, a magnetic head has been proposed in which a thin film of the metal magnetic material as described above is formed on a substrate, and the thin films are laminated with an insulating layer interposed therebetween. For example, FIG. 4 shows a perspective view of a conventional magnetic helad core. The core part 1 is a substrate part on which a metal magnetic thin film is formed, and the core part 1 is a substrate part on which a metal magnetic thin film is formed.
A composite magnetic head has been proposed, which is made of a metal magnetic material and has an X-shape slanted shape, with the crest ′ formed by a snow arm, an arm, or the like. However, in the case of such a head, C,
After joining the I core, when processing the I core to a predetermined gap depth so as to have a minute gap depth of preferably 2 to 10 μm,
As shown in Fig. 4(b) K, the side with the C window for winding (C
If the substrate portion 1 and the magnetic film 2 of the core (core) are parallel to the gap portion, and for example, the adhesion between the substrate portion 1 and the magnetic film 2 is insufficient and a gap or step occurs, it will act as a pseudo gap. However, it has the disadvantage that so-called "interference" effect occurs, which may impede recording and reproduction. In addition, the apex portion of the magnetic film 2 has a length with a radius of curvature due to wraparound during sputtering, which has the disadvantage of lowering head efficiency. In addition to the above-mentioned head structure, Japanese Patent Application No. 105846/1983 discloses a structure in which a ferrite layer is laminated with a magnetic film to prevent the above-mentioned contour effect, a groove in which a plurality of 7-shaped grooves are formed in the groove, and a structure in which a circular arc-shaped groove is formed. Some proposals have been made to counteract the contour effect by applying

[Problem that the invention seeks to solve]

However, in the composite magnetic head proposed in Japanese Patent Application No. 58-105846, the substrate portion corresponding to the track is provided with a plurality of figure-7 grooves or arc-shaped grooves. There are some drawbacks, such as the fact that there are limitations. Further, in the case of FIG. 4 described above, when the head is completed, the substrate portion (C core side) and the magnetic film portion are parallel to the gear, and a pseudo gap is observed in that portion, resulting in a decrease in head efficiency.

Therefore, the object of the present invention is to have a structure in which each core formed in a V-shape faces each other, and the radius of curvature at the apex portion is reduced by 1 minute, so that the pseudo gap is substantially reduced. This provides a highly efficient magnetic head.

[Rounding method to solve problems]

In view of the above-mentioned problems, the inventors of the present invention conducted extensive research and found that after attaching a multilayer magnetic film, the track portion was molded and protected with glass or the like, and then a predetermined groove width was processed. d
) As shown in K, the curvature of the knee pex of the magnetic film part of the C-shaped core to which the winding is applied should be sufficiently removed, and the knee pex of the ferrite should be in an area where it does not become parallel to the gap even during gear and depth processing. The present invention has been completed by discovering that the pseudo gap can be substantially prevented by removing the magnetic film parallel to the gap so as to fully satisfy the above two conditions.

That is, in the composite magnetic head of the present invention, a pair of substrates on which a plurality of magnetic films are laminated are bonded to each other via an insulating layer 7 with a gap between them, and the magnetic film is formed in the width of the center and the width of the groove. Embodiment 1 [Example] The present invention will be explained in detail with reference to the following examples.

[Embodiment 1] FIG. 2 is a diagram schematically showing an embodiment of the magnetic head of the present invention. An enlarged view of the magnetic core 6 is shown in FIG. This head consists of a slider 4, a magnetic core 6, and an embedded glass 5. The magnetic core 6 is fixed by molding with a material such as glass into a slit formed on one of the two air bearing surfaces of the slider 4. has been done.

The detailed structure of one example of the magnetic core 6 is shown in Figures 1 (&) to (d).
This is the circular shown in . Suba on Mu-Zn ferrite 1,
It has a structure in which metal magnetic films 2, 2' and insulating layers 7, which are formed by a method using a conventional method, are alternately laminated. The metal magnetic film is, for example, F
@-A1. High magnetic permeability alloys such as Si alloy (Sendust), N1-F alloy (・(-Malloy), Fs-81 alloy) or Co-Zr amorphous alloy are formed by splicing, polishing, etc. In addition, the insulating layer can be TI, A
A nonmagnetic insulator such as t205 or 810□ can be formed by sputtering or the like. The track portion of the C core, which is one of the pair of magnetic core members, ie, FIG. 1(C)
By stepping the magnetic film 2 parallel to the gap as shown in FIG. 1, the curvature of the apex portion shown by the dotted line in FIG. The apex has a structure in which areas that are not parallel to the gap are removed during gap depth machining.

When Sendust is used as the metal magnetic material, the preferable composition is A13 to 7 at%, Sl 7 to 11 at%, and Fe 82 to 9 Qat%. (for the purpose of obtaining high magnetic permeability) -14.5 to 6.5 at%, S18. O~io, 5
It is more preferable to have a composition of ats, Fe of 83 to 87 at%. Further, 5102 is preferable as the insulating layer. A feature of the present invention is that by removing the magnetic film portion as described above, the gap portion, the substrate, and the magnetic film substantially intersect obliquely even after the gap depth processing. The amount of magnetic film removed is 4 μm to 5 μm since the magnetic film thickness is 3 μm x 3 layers.
And so.

This removal method includes so-called mechanical processing such as grinding or lapping, or chemical removal method, but in this embodiment, mechanical grinding was adopted. The grinding wheel used for grinding was a diamond grinding wheel, and the binder was resin. The abrasive grain size was 2 to 6 μm, and the concentration was 100.

Further, the insulating film thickness was 5so2 and the thickness was 0.05 μm.

In order to improve the magnetic permeability of the multi-layer metal film, it is formed on P4 ivy and heated at 400℃ to 800℃ in an inert gas such as N2.
Heat treatment at ℃. It is preferably carried out at a temperature of 500°C to 700°C for 0.3 to 2 hours, preferably 0.5 to 1 hour. The heat treatment may be performed simultaneously with the glass mold.

The head obtained as described above was buried in the slider shown in Fig. 2, and the electromagnetic conversion characteristics of the head were investigated.
It is a diagram. The test conditions at this time were as follows. The winding wire was a 35 μm θ type urethane enamel parallel wire made of copper and wound in two bifilar layers for a total of 28 turns. The medium used was He 69906'' 80Co-2ONi sputtering medium.

The flying height of the magnetic head was 0.251 Irn. Fifth
As can be seen from the figure, the relative output ratio of the magnetic head of the present invention is improved by about 12 inches compared to the conventional product. The reason for this is that according to the present invention, the stepped effect reduces the leakage magnetic flux from the apex portion during recording, making it easier to generate an urgent magnetic field at the head tip, which means that the head efficiency is significantly improved compared to conventional products. This is probably because it has been improved. Naturally, no pseudo gap was observed in the head of the present invention.

[Example 2] NiO: Mn0-30: Non-magnetic substrate of 70 mol % (thermal expansion coefficient 131 x 10-' d@
g-') was polished to a mirror surface using diamond abrasive grains with a diameter of 1 μm, and then subjected to the same treatment as in Example 1, and an amorphous alloy magnetic film of CoB6,5Nb10,5ZrLO was sputtered thereon. The film was formed using The process was carried out using a flat plate magnetron type device under the following conditions.

Target 126 alloy Tada, Toargon pressure
5 X IQ Torr substrate temperature 110
℃ Distance between electrodes 108 ■ Magnetic film thickness 3 ItrnX 3 /il Insulating layer 5
io2 was 0.05 μm.

By using the above method, the magnetic structure shown in FIG. 1 can be obtained.

I created Dochi f. Track width is 15μm, gear, 7
The # length was 0.31 μm. As a result of the head evaluation, as in Example 1, no pseudo gap was observed and the head was highly efficient as shown in FIG.

The effects described in detail above are effective over a wide range regardless of whether the substrate material is magnetic or non-magnetic or the material of the alloy thin film material.

〔Effect of the invention〕

As detailed above, in the composite magnetic head of the present invention, not only the multilayer magnetic films are substantially obliquely crossed in an X shape, but also the knees 4 of the magnetic film portion. The cross section also has no radius of curvature, so there are no false gaps and high efficiency.

This has the remarkable effect of providing the following information.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) show a schematic diagram and a top view of a composite magnetic head of the present invention. Figure 1 (e), (d
) shows each cross-sectional view of FIG. 1(b). FIG. 2 is a perspective view of a magnetic head in which the magnetic core of the present invention is assembled into the head. FIG. 3 is an enlarged view of the magnetic core portion of FIG. 2. FIGS. 4(a) and 4(b) show a schematic diagram and a top view of a conventional composite magnetic head. Figure 4 (e), (d)
shows each cross-sectional view of FIG. 4(b). FIG. 5 shows the evaluation results of electromagnetic conversion characteristics. 1: Substrate, 2.2': Magnetic film, 3 Ni glass, 4 Ni slider, 5: Embedded glass, 6: Magnetic core, 7.7': Insulating layer, 8: Gap. Figure 1 ×-x town ■ Figure 3 ″ Address: 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Name (5
08) Target of amendment by Hitachi Metals Co., Ltd. “Claims” column of the specification. "Detailed Description of the Invention" column and "Brief Description of Drawings" column. Contents of the amendment As shown in the attached sheet, the description in the column ``Contents of the amendment (■), 1 claim in the specification'' will be corrected as follows. 1. An alloy magnetic film with a high saturation magnetic flux density is formed on a pair of substrates, and the magnetic films are bonded via a gap, and winding is performed in a magnetic head in which the magnetic film has an oblique shape in an X shape.C
A composite magnetic head characterized by a structure in which the apex part of the magnetic film part of the mold core is stepped parallel to the gap part, thereby sufficiently eliminating the curvature part of the apex part. 2. In the composite magnetic head described in claim 1, when the magnetic film is removed parallel to the gap, the apex portion is removed to a region where the apex of the ferrite does not become parallel to the gap during gap depth adjustment. Composite magnetic head device characterized by a structure (2) The description in the "Detailed Description of the Invention" column of the specification is corrected as follows. 1. Change "100000" in line 13 of page 2 to [1000
Q #e Correct to J. 2, page 6, line 18, rFc-AI Si alloy”
r”e -AI-Si Alloy J '' column is corrected as follows. 1, page 11, line 12, r7,7': Insulating layer"
7: Insulating layer”. that's all

Claims (1)

[Claims] 1. An alloy magnetic film with a high saturation magnetic flux density is formed on a pair of substrates, and the magnetic films are connected through a gap to form a winding in a magnetic head having an oblique shape in an X shape. A composite magnetic head characterized by a structure in which the apex part of the magnetic film part of the C-shaped core is stepped parallel to the gap part, thereby sufficiently eliminating the curvature part of the apex part. 2. In the composite magnetic head according to claim 1, when the magnetic film is removed parallel to the gap, the apex portion of the ferrite is removed to a region where the apex of the ferrite does not become parallel to the gap during gap depth processing. A composite magnetic head featuring: