JPH0620219A - Composite magnetic-head chip and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a magnetic disk device wherein an overwrite characteristic is enhanced and a noise is small by a method wherein two kinds of metal magnetic thin films whose saturation flux density is different from each other are applied to the gap opposite face of a core. CONSTITUTION:In a composite magnetic-head chip, a first metal magnetic thin film 4 whose permeability is large and whose saturation flux density is high is applied to the gap-side opposite face of a ferrite core 1 and, in addition, a second metal magnetic thin film 5 whose saturation flux density is larger than that of the first metal magnetic thin film is applied to its surface. In the manufacturing method of the composite magnetic-head chip, the metal magnetic thin films 4, 5 as two layers are applied to the ferrite core 1 and, after that, the magnetic-head chip is heat-treated at 500 to 700 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for a magnetic tape device and a magnetic disk device, and more particularly to a composite magnetic head chip for recording / reproducing information on / from a magnetic disk and a method for manufacturing the same, and more particularly to improving overwrite characteristics. It was made.

[0002]

2. Description of the Related Art A floating magnetic head is a monolithic head in which a slider and a magnetic head chip are integrally formed by using a magnetic material (for example, Mn-Zn ferrite) and a non-magnetic material (for example, CaTiO ₃ , Al ₂ O). _3- TiC)
The slider is roughly divided into a composite head in which a magnetic head chip made of a magnetic material is embedded. These magnetic head chips include a composite type in which a pair of ferrite cores are opposed to each other via a magnetic gap, and a metal magnetic thin film such as sendust or an amorphous alloy is attached to at least one of the opposed surfaces. Demand for composite type magnetic head chips is increasing due to their magnetic properties.

Since the conventional composite type magnetic head chip has the core coated with the metal magnetic thin film, the wear is not uniform and the wear is evenly reduced, resulting in a change in the characteristics. Are described in JP-A-63-81609. In this case, Fe having a high magnetic permeability and a high saturation magnetic flux density is provided on at least one of the facing surfaces of the pair of ferrite cores.
-Al-Si-Co alloy magnetic layer is formed, and Fe-Al-Si-Co or Fe-Al having the same magnetic permeability as the above, a lower Co content and a lower saturation magnetic flux density is formed on the magnetic layer.
A -Si alloy magnetic layer is formed to prevent uneven wear of the magnetic head chip. When the magnetic saturation of a part of the magnetic alloy thin film of the composite type magnetic head chip becomes extremely high, the magnetic permeability of sendust tends to decrease sharply. As a result, even if the magnetomotive force, that is, the recording current is increased, the leakage magnetic flux involved in the recording hardly increases, and the linearity of the recording strength of the magnetic tape with respect to the magnetomotive force is lost. Therefore, there is a problem in that the recording / reproducing waveform of the signal is distorted, and a solution thereof is disclosed in Japanese Patent Laid-Open No. 2-216604. In the solved magnetic head chip, two metal magnetic thin films having different saturation magnetic flux densities are deposited on the gap facing surfaces of a pair of cores, and the two metal magnetic thin films have a higher saturation magnetic flux on the gap side than on the core side. In terms of density, the linearity of the recording strength of the magnetic tape with respect to the magnetomotive force is improved, and the distortion of the recording / reproducing waveform is eliminated.

[0004]

As described above, the conventional composite type magnetic head chip is coated with two kinds of metal magnetic thin films on the gap facing surface of the core to prevent uneven wear of the magnetic head chip. Although the linearity of the recording strength of the magnetic tape with respect to the magnetomotive force is improved to eliminate the distortion of the recording / reproducing waveform, no consideration has been given to the overwrite characteristic. For this reason, when new magnetic recording is overlaid on a portion recorded on the magnetic recording medium, the previous magnetic recording cannot be sufficiently erased, which causes noise. In view of the above, the present invention provides a composite magnetic head chip in which a magnetic disk device having two types of metal magnetic thin films having different saturation magnetic flux densities, which are different in saturation magnetic flux density from each other, is applied to the magnetic disk device to improve overwrite characteristics and reduce noise. It is intended to be obtained.

[0005]

SUMMARY OF THE INVENTION The present invention is a composite magnetic head in which a pair of ferrite cores are arranged to face each other via a magnetic gap, and a metal magnetic thin film is deposited on the facing surface of at least one of the cores. The chip achieves the above object. Therefore, the first metallic magnetic thin film having a large magnetic permeability and a high saturation magnetic flux density is deposited on the facing surface on the gap side of the ferrite core, and the second metallic magnetic thin film having a larger saturated magnetic flux density is coated on the surface thereof. It is worn. The first metal magnetic thin film is formed of sendust, and the second
The metal magnetic thin film of can be formed of super sendust. The first metal magnetic thin film and the second metal magnetic thin film each have an interdiffusion phase. Further, Ni in the second metal magnetic thin film diffuses into the first metal magnetic thin film, and the Ni content gradually decreases from the magnetic gap side toward the ferrite core side. Further, the track portion on the gap side of the magnetic head chip was drawn. A method of manufacturing a levitation type composite magnetic head according to the present invention comprises applying a first metal magnetic thin film made of sendust on a gap side surface of a ferrite core,
Next, the second metal magnetic thin film made of super sendust having a larger saturation magnetic flux density than that is deposited on the surface of the first metal magnetic thin film, and then heat-treated at a temperature condition of 500 to 700 ° C. Heat treatment condition is 500-700 ° C
Is the B.I. of the first metal magnetic thin film and the second metal magnetic thin film. C. This is to improve the regularity of the C structure.

The overwrite characteristic which is the object of the present invention will now be described. When magnetic recording is performed on the magnetic recording medium by the magnetic head and then magnetic recording is overlaid on the magnetic recording medium, the previous magnetic recording is erased and new magnetic recording is performed. In this case, the natural logarithm of the ratio of the magnetic recording left unerased to the new magnetic recording is the overwrite characteristic, and the larger the absolute value, the more the previous magnetic recording does not remain. Will be good.

Recently, as the recording density has increased, the coercive force of the magnetic recording medium has increased, and the gap length of the magnetic head chip has become smaller. This causes the above-mentioned deterioration of the overwrite characteristic. The present inventor has conducted diligent research to solve this problem. That is, the recording wavelength must be reduced in order to cope with the high recording density, and as a result, the magnetic gap length is also reduced. However, when the magnetic gap length becomes smaller, the recording magnetic field becomes smaller, and as a result, when newly recording data on the previously recorded data, erasing the previously recorded magnetic data becomes insufficient, The overwrite characteristic deteriorates, which causes noise. In order to solve this problem, the magnetic flux density of the metal magnetic thin film of the magnetic head chip should be increased to increase the recording magnetic field, but when the magnetic head was created by increasing the magnetic flux density of the metal magnetic thin film, the magnetic permeability was It has been found that the reproduction characteristics of the magnetic recording device deteriorate as a result. Based on the above research results, the above problem was solved by providing two layers of metal magnetic thin films having different saturation magnetic flux densities in the gap portion of the magnetic head chip, and the magnetic flux density and magnetic permeability were improved. Provide the head.

[0008]

In the above magnetic head chip, the first metallic magnetic thin film having a high magnetic permeability and a high saturation magnetic flux density is deposited on the gap surface of the core, and the second metallic magnetic thin film having a higher saturated magnetic flux density is formed on the surface thereof. Since it is deposited, the magnetic permeability can be increased even if the magnetic flux density is increased. Therefore, the overwrite characteristic is improved and the recording / reproducing characteristic is not deteriorated. The magnetic permeability can be improved by heat treatment of the magnetic head. C. This is because the atoms are regularly arranged in the C structure. In addition, since the two metal magnetic thin films each have an interdiffusion layer, they have good bonding properties,
Film peeling is unlikely to occur.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the composite type magnetic head chip of the present invention will be described with reference to FIGS. In the magnetic head chip, a magnetic gap 3 is provided between the I core 1 and the C core 2, and two layers of metal magnetic thin films 4 and 5 are covered on at least one gap facing surface of the I core 1 and the C core 2. The magnetic recording / reproduction can be performed between the magnetic disk and the magnetic disk which is mounted on the magnetic disk and is disposed outside the gap 3 so as to face the magnetic disk. The I core 1 and the C core 2 near the gap 3 are joined by a glass material 6, and in this embodiment, the track portion 11 on the gap side is drawn by a notch. Then, as shown in FIG. 3, the magnetic head chip 7 thus constructed is inserted into the slit 9 of the non-magnetic slider 8 and fixed by the mold glass 10 to form a flying composite magnetic head.

The I core 1 and the C core 2 are Mn--Zn.
A first metal magnetic thin film 4 made of ferrite and made of sendust is applied to the gap facing surface of the I core 1, and a second metal magnetic thin film 5 made of super sendust having a saturation magnetic flux density higher than that of sendust is attached to the surface thereof. It is covered. The composition of the first metal magnetic thin film 4 is Fe-Al-Si.
And the composition of the second metal magnetic thin film 5 is Fe-Ni-Al.
-Si, both metal magnetic thin films 4 and 5 each have an interdiffusion phase, and the Ni content gradually decreases from the gap 3 side toward the I core 4 side. In this case,
As shown in FIG. 2A, two layers of metal magnetic thin films 4 and 5 are deposited on only one of the pair of cores 1 and 2.
As shown in (b), two layers of metal magnetic thin films 4 and 5 may be attached to both cores.

In manufacturing the above-mentioned composite magnetic head chip, sendust is deposited on the surface of the I core 1 facing the gap to a thickness of 0.8 to 1.2 μm by sputtering using an alloy target containing Fe, Al and Si. Then, super sendust is sputtered thereon with an alloy target containing Fe, Ni, Al and Si to a thickness of 0.
It is deposited to 8 to 1.2 μm. Next, the I core 1 coated with the metal magnetic thin film was kept at 670 ° C. for 1 hour so that sendust and super sendust each had an interdiffusion layer. By this mutual diffusion, the Ni content is diffused so as to gradually decrease from the gap 3 side toward the I core 1 side. After that, the I core 1 and the C core 2 are joined with the glass material 6 so as to have the gap 3. The above-mentioned sputter has an RF power of 350 W, a target-core distance of 70 mm, a core temperature of 300 ° C., and an ultimate vacuum of 5 × 10 ^−4.
It was performed under the conditions of Pa and gas pressure of 7 × 10 ⁻¹ Pa.

Magnetic permeability μ, magnetic flux density B and coercive force Hc of the magnetic head chip prepared as described above were measured and the results are shown in Table 1. In addition, in Table 1, for comparison, Comparative Example 1 in which only one layer of sendust was applied to the ferrite core and Comparative Example 2 in which only one layer of super sendust was applied to the ferrite core were produced, and Was also measured in the same manner and the results are shown. Each magnetic head chip was heat-treated at 670 ° C. Table 1 below
According to the results, the magnetic head of the present invention has both higher magnetic permeability and magnetic flux density than the comparative example.

[0013]

[Table 1]

Next, each magnetic head chip shown in Table 1 was tested for overwrite characteristics, reproduction output characteristics, generation of pseudo gaps, and film peeling of the metal magnetic thin film, and the results are shown in Table 2.

[Table 2] It can be seen from Table 2 above that the present invention has better overwrite characteristics and reproduction output than the comparative example. It can be seen that this corresponds to the high permeability and high magnetic flux density of the present invention shown in Table 1 above. Also, with respect to film peeling, the present invention is less likely to peel. It is considered that this is because the two layers of the first and second magnetic metal thin films have mutual diffusion layers.

[0015]

According to the composite type magnetic head chip of the present invention,
Since two layers of metallic magnetic thin films composed of sendust and super sendust are applied to the facing surface of the ferrite core on the gap side, both the magnetic flux density and the magnetic permeability can be increased, and the overwrite characteristics are improved to reduce noise. It can be prevented from occurring, and the reproduction output is improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a composite magnetic head chip of the present invention.

FIG. 2 is a partial perspective view of two different types (a) and (b) near the gap of the composite magnetic head chip.

FIG. 3 is a perspective view of a floating composite magnetic head.

[Explanation of symbols]

 1 I core 2 C core 3 Gap 4 First metal magnetic thin film 5 Second metal magnetic thin film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigekazu Suwabe 5200 Mikashiri, Kumagaya-shi, Saitama Hitachi Metals Co., Ltd.

Claims (6)

[Claims] 1. A magnetic head chip in which a pair of ferrite cores are arranged to face each other via a magnetic gap, and a metal magnetic thin film is adhered to the facing surface of at least one of the cores. Is coated with a first metal magnetic thin film having a large magnetic permeability and a high saturation magnetic flux density, and a second metal magnetic thin film having a larger saturation magnetic flux density is deposited on the surface thereof. Composite type magnetic head chip. 2. The composite magnetic head chip according to claim 1, wherein the first metal magnetic thin film is made of sendust, and the second metal magnetic thin film is made of super sendust. 3. The first metal magnetic thin film and the second metal magnetic thin film each have an interdiffusion phase, and the Ni content gradually decreases from the magnetic gap side toward the ferrite core side. The composite type magnetic head chip according to claim 1. 4. The composite magnetic head chip according to claim 1, wherein the track portion on the gap side is drawn. 5. A flying composite magnetic head, wherein the composite magnetic head chip according to claim 4 is mounted in a slit of a non-magnetic slider. 6. A method of manufacturing a composite magnetic head chip, comprising a pair of ferrite cores arranged to face each other with a magnetic gap interposed therebetween, and a metal magnetic thin film deposited on the facing surface of at least one of the cores. A first metal magnetic thin film made of sendust having a high magnetic permeability and a high saturation magnetic flux density is applied to the surface of the ferrite core on the gap side, and then a super sendust having a larger saturation magnetic flux density than that on the surface of the first metal magnetic thin film. A second metal magnetic thin film consisting of
A method for manufacturing a composite magnetic head chip, characterized in that the heat treatment is performed under a temperature condition of 00 to 700 ° C.