JP2003346306A - Magnetic memory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film-magnetic recording head, that uses a thin film material of high magnetic saturation density with a large resistivity suitable for a magnetic recording device which can secure a media transfer speed of 15 MB/s or higher, by avoiding access time increases and transfer speed drops due to the high recording density, and to provide its manufacturing method and a magnetic recording device using it. <P>SOLUTION: By manufacturing a magnetic film having a high saturation magnetic flux density of 1.5 T or higher and a resistivity of 40 μΩcm or higher by a frame plating method, after adding 40 to 60 Ni-Fe and Co, Mo, Cr, B, In, Pd, and the like to its material, it is possible to obtain a recording head which can make satisfactory recording in high-frequency ranges, and to obtain a high-density magnetic recording device which makes a disk turn at 4000 rpm or a higher speed, with a media transfer speed of 15 MB/s or higher at a recording frequency of 45 MHz or higher. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic core for a magnetic head, and more particularly to a recording head of a separate recording / reproducing magnetic head for high recording density.

[0002]

2. Description of the Related Art In recent years, as the recording density of magnetic disk devices has increased, the coercive force of recording media has increased, and there has been a demand for a thin-film magnetic head capable of sufficiently recording on the high coercive force medium. For this purpose, it is necessary to use a material having a high saturation magnetic flux density (B _S ) as a core material of the magnetic head. Conventionally, a Ni—Fe alloy film having a thickness of about 3 μm has been used as these materials. However, this Ni
Since the Fe alloy film has a low specific resistance of 16 to 20 μΩcm, the eddy current loss is large, so that the recording magnetic field intensity in a high frequency region is reduced, and the recording frequency is at most 30 MHz.
The limit is about z. As an alternative material, C
An o-based amorphous material, an Fe-Al-Si-based sendato alloy thin film, etc. have been proposed, but the former is amorphous and therefore thermally unstable, and the latter is as high as 500 ° C. Due to the need for heat treatment at temperature, there is a problem in the manufacturing process as a magnetic core material for magnetic disks,
It has not been put to practical use. Recently, a Co-Ni-Fe ternary material has been proposed as a magnetic core material for a thin-film magnetic head (JP-A-60-82638, JP-A-61-76642).
JP-A-64-8605, JP-A-2-68906, JP-A-2-2-2
90995).

[0003]

THE INVENTION Problems to be Solved] The ternary material saturation magnetic flux density (B _S) is above the high 1.5T, Ni-
As in the case of the Fe alloy film, no consideration was given to the specific resistance and the crystal grain size.

On the other hand, the storage capacity of magnetic disk devices has been steadily increasing year by year, and the surface recording density of currently commercialized 3.5-inch devices has been increased to 350 Mb / in ² at the maximum. The data recording frequency in this case is 27 MH
z, which is equivalent to that of a conventional Ni-Fe alloy film or Co-
The Ni—Fe alloy film is approaching the performance limit of the magnetic head.

[0005] Also, 40-55Ni-F
Japanese Patent Application Laid-Open No. 3-68744 has been proposed as a magnetic film formed by a sputtering method in which Nb, Ta, Cr, Mo, etc. are added to e. It is difficult to form a thick film.

An object of the present invention is to provide a magnetic head for high recording density in a high frequency region, that is, a high speed access and high speed transfer, and a magnetic storage device using the same.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been made in consideration of the above-described problems. A magnetic disk device for achieving high-speed transfer and high recording density, that is, a magnetic disk device which performs magnetic recording and reproducing during recording / reproducing. The disk rotates at 4000 rpm or higher and is mounted on a magnetic storage device whose recording frequency is set to 45 MHz or higher. As a thin-film magnetic head for exhibiting its performance, the saturation magnetic flux density (B _S ) is large, A material having a small coercive force and a large specific resistance is required. Therefore, the composition region where the specific resistance is high and the saturation magnetic flux density is high is in the range of Ni: 38 to 60% by weight.
However, since this composition region has the largest range of crystal magnetic anisotropy, when a magnetic film having a thickness of 2 μm or more which is usually applied to a thin film magnetic head or the like is formed by a sputtering method or the like, the crystal grains of the film are reduced. It becomes large, the coercive force is large, and uniaxial anisotropy is hardly imparted.

In view of this, a plating method capable of suppressing crystal grains is taken up, and the addition of a third element such as Co, Mo, Cr, Pd, B, or In based on a 38-60% by weight Ni--Fe binary alloy is studied. And a film thickness of 2 to 5 μm to obtain a required recording magnetic field.
m, the saturation magnetic flux density (B _S ): 1.5 T or more,
Coercive force (H _CH ): less than 1.0 Oe and specific resistance 40 μΩ
The present invention has found a composition range and a manufacturing method of an excellent thin film having a thickness of not less than cm. By using these materials for the thin film magnetic head, the areal recording density: 500 Mb / in ² or more,
A high-performance magnetic storage device having a recording frequency of 45 MHz or more and a transfer speed of 15 MB / s or more can be provided.

The present invention relates to a thin-film magnetic disk for recording information, a rotating means for the thin-film magnetic disk, a thin-film magnetic head provided on a floating type slider for performing writing and reading of information, and particularly for separately performing these operations. A moving means for supporting the floating slider and accessing the thin-film magnetic disk, wherein at least one of the upper magnetic core and the lower magnetic core of the write magnetic core of the thin-film magnetic head has an average crystallinity. Particle size 500Å
The magnetic storage device is made of a metal magnetic material having a room temperature specific resistance of 40 μΩcm or more and a coercive force in a hard axis direction of 1.0 Oe or less.

Further, according to the present invention, at least one of the upper magnetic core and the lower magnetic core of the write magnetic core of the thin-film magnetic head is 38 to 60% by weight of Ni and Fe
It is characterized by comprising an electroplated thin film of a Ni-Fe alloy having a content of 40 to 62% by weight.

Further, the present invention provides a disk-shaped magnetic disk having a media transfer speed of 15 megabytes or more per second, a surface recording density of recorded data of 500 megabits or more per square inch, and an information storage medium having a diameter of 3.5 inches or less. Wherein the magnetic disk rotates at 4000 rpm or more during recording / reproducing, the recording frequency is 45 MHz or more, and at least the upper magnetic core of the thin-film magnetic head for performing the recording has a Ni weight of 38 to 60 wt. % And an Fe—40 to 62% by weight Ni-Fe alloy having a thickness of 1 to 5 μm and an average crystal grain size of 5%.
The recording head is characterized in that the specific resistance is 40-60 μΩcm, the coercive force in the hard axis direction is 1.0 Oe or less, and the recording magnetomotive force of the recording magnetic head is 0.5 Amp-turn or more.

[0012] The magnetic core according to the present invention is Co1 by weight.
It can contain at least one of 5% by weight or less and one or more of Mo, Cr, Pd, B and In in a total amount of 3% by weight or less.

Further, the present invention relates to a thin film magnetic disk for recording information, a rotating means for the thin film magnetic disk, and a read / write separation type thin film provided on a floating type slider for writing and reading information with separate elements. In a magnetic storage device having a magnetic head and a moving means for supporting the floating slider and accessing the thin-film magnetic disk, the magnetic film of the thin-film magnetic head of the recording section has the same characteristics and composition as those described above. It is characterized by using a thing.

Further, the present invention relates to a disk-shaped magnetic medium having a medium transfer speed of 15 megabytes or more per second, a surface recording density of recorded data of 500 megabits or more per square inch, and an information storage medium having a diameter of 3.5 inches or less. In a magnetic storage device having a disk, the magnetic disk rotates at 4000 rpm or more during recording / reproducing, has a recording frequency of 45 MHz or more, and has a separate read / write thin film magnetic head for performing the recording / reproducing with separate elements. The thin-film magnetic head for performing the recording is characterized in that at least the upper magnetic core has the same characteristics and composition.

According to the present invention, there is provided a lower magnetic film, wherein one end formed on the lower magnetic film is in contact with one end of the lower magnetic film, and the other end is opposed to the other end of the lower magnetic film via a magnetic gap;
A thin-film magnetic device comprising: an upper magnetic film that forms a magnetic circuit having a magnetic gap partially with the lower magnetic film; and a conductor coil that forms a predetermined number of turns of a coil that passes between the magnetic films and intersects the magnetic circuit. In the head, at least one of the lower magnetic film and the upper magnetic film is formed by a plating method, and is Ni in an amount of 38 to 60% by weight and Fe in an amount of 40 to 62%.
% Of a Ni-Fe alloy containing 1% by weight.
.About.5 .mu.m, an average crystal grain size of not more than 500 DEG, and a coercive force in a hard axis direction of not more than 1.0 Oe.

According to the present invention, a lower magnetic film is formed on the lower magnetic film, one end of which is in contact with one end of the lower magnetic film, and the other end of which faces the other end of the lower magnetic film via a magnetic gap;
A thin-film magnetic device comprising: an upper magnetic film that forms a magnetic circuit having a magnetic gap partially with the lower magnetic film; and a conductor coil that forms a predetermined number of turns of a coil that passes between the magnetic films and intersects the magnetic circuit. In the method of manufacturing a head, at least one of the lower and upper magnetic films is formed by plating a metal bath with Ni ++ ions having a metal ion concentration of 15 to 20 g / l and Fe ++ ions having a metal ion concentration of 2.0 to 2.7 g / l. And the ratio of Ni ++ ions to Fe ++ ions (Ni ++ / Fe +
+) Comprises 7-8, a stress relieving agent and a surfactant,
A method for manufacturing a thin-film magnetic head, characterized in that the thin-film magnetic head is formed by electroplating using an Ni-Fe alloy electroplating bath having a pH of 2.5 to 3.5.

In particular, the bath temperature is kept at 20 to 35 ° C.,
It is preferable to manufacture by frame plating in a magnetic field at a current density of ３０30 mA / cm ² .

Further, in the present invention, Co ions are added in an amount of 0.4 to 0.6.
g / l, Cr, Mo, Pd, In, and B ions are each added to 0.1 g.
1 g / l or less is added. Further, the present invention is preferably made by electroplating with a frame in a magnetic field.

According to the present invention, the film thickness, the specific resistance, and the relative magnetic permeability are designed in consideration of the eddy current loss of the magnetic pole magnetic film of the recording head.
The problem can be solved by preventing the fluctuation of the write bleed amount or the overwrite value accompanying the recording frequency, and by setting the data recording frequency high and rotating the magnetic disk suitable for the head at a high speed.

(1) The media transfer rate is 1 per second
It is preferable to have a unit that has a surface recording density of 5 megabytes or more and a recording density of 500 megabits or more per square inch.

(2) When storing information on a disk-shaped magnetic disk having a diameter of 3.5 inches or less, the magnetic disk rotates at 4000 rpm or more during recording and reproduction, and the recording frequency is set to 45 MHz or more. Is preferred.

(3) It is preferable to have a magnetic disk using a metal magnetic film having a coercive force of 2 kOe or more.

(4) The rise time of the recording current is preferably set to 5 nanoseconds (ns) or less.

(5) The recording coil of the induction type magnetic head for recording information on the magnetic disk medium is formed by using a thin film process, the number of terminals is 3, and the inductance between each terminal is 1 micron. Henry (μH) or less is preferable.

(6) The recording coil of the induction type magnetic head for recording information on the magnetic disk medium has a two-layer structure.
It is preferable that the number of windings of the first-layer coil and the number of windings of the second-layer coil are equal, and the winding directions are opposite to each other.

(7) The recording coil of the induction type magnetic head for recording information on the magnetic disk medium has a single-layer structure.
Another terminal is connected to a position (c) corresponding to half of the number of turns between the coil start point (a) and the end point (b), and (c)-
It is preferable that the currents flowing between (a) and (c)-(b) have opposite phases.

(8) The thickness of the magnetic film constituting the recording pole of the magnetic head used for data recording or recording / reproducing is d (μm), the specific resistance is ρ (μΩcm), and the relative magnetic permeability in the low frequency region is When μ, each parameter is μ
It is preferable to have a means that satisfies the relationship d ² / ρ ≦ 500.

(9) At least a part of the recording magnetic pole of the magnetic head used for data recording or recording / reproducing has a multilayer structure in which magnetic layers and insulating layers are alternately laminated. It is preferably not more than 0.7 μm.

(10) The above-mentioned Fe—Ni-based alloy is used for at least the upper magnetic material of the recording magnetic material of the magnetic head used for data recording or recording / reproducing, and the Co-based amorphous alloy or the Fe-based non-alloy is used for the lower magnetic material. It is preferable to use a crystalline alloy.

(11) The recording pole material of the magnetic head preferably contains at least one of Zr, Y, Ti, Hf, Al and Si.

(12) The recording magnetomotive force of the magnetic head used for data recording or recording / reproducing, that is, the product of the recording current and the number of coil turns, is set to 0.5 ampere turn (AT) or more. Is preferred.

(13) It is preferable that the specific resistance of at least a part of the recording magnetic pole of the magnetic head used for data recording or recording / reproducing be 40 μΩcm or more and the relative magnetic permeability be 500 or more.

(14) The recording coil of the induction type magnetic head for recording information on the magnetic disk medium has a single-layer structure, and corresponds to half the number of turns between the coil start point (a) and the end point (b). Another terminal is connected to the position (c),
The currents flowing between (c) and (a) and between (c) and (b) have opposite phases, and a read / write separation type using a spin-valve element or a giant magnetoresistive element as a reproducing head. It is preferable to use a head.

In a high frequency region of a recording frequency of 45 MHz or more, eddy current loss is dominant in the head efficiency (efficiency of inducing magnetic flux) of the magnetic head. Therefore, in order to reduce the eddy current loss, it is most effective to reduce the thickness of the magnetic core. However, if the thickness is reduced, the recording magnetic field becomes insufficient and recording becomes impossible. Coercive force: 2000 Oe or more, especially 2300 Oe
In order to sufficiently record data on the medium having a high coercive force, not only the saturation magnetic flux density is high but also the film thickness needs to be 2 μm or more. Normally, a multilayer film is used to reduce the eddy current loss, but it is difficult in terms of dimensional accuracy in a head process corresponding to a high recording density. Therefore, it is necessary to reduce the eddy current loss by increasing the specific resistance of the magnetic core and extend the frequency characteristic of the magnetic permeability (μ) of the magnetic core to the high frequency side.

Ni—Fe binary magnetic film (thickness: 3 μm)
In the case of Ni, a saturation magnetic flux density (B
_S ) is 1.5T or more, and the specific resistance (ρ) is 40
〜50 μΩcm. That is, when Ni is less than 38% by weight, the specific resistance (ρ) is high, but the saturation magnetic flux density (B _S ) is high.
Falls below 1.5T. On the other hand, if the Ni content exceeds 60% by weight, the saturation magnetic flux density (B _s ) also falls below 1.5T, which is not preferable. In particular, 40 to 50% by weight is preferable. When a film having such a composition is produced, a plating method is preferable. That is, the coercive force can be reduced even with the present composition having large crystal magnetic anisotropy in order to make the crystal grain size extremely fine by electroplating, and the crystal orientation can be minimized. For example, if the orientation ratio of the crystal is (111)
/(200)<5.0. Ni and Fe of the plating bath composition for producing such a film
The ion concentration is Ni ++: 15 to 20 g / l, Fe ++: 2.
0 to 2.7 g / l, and the ion ratio (Ni ++ / Fe ++) is 7
-8. The plating current density at this time is 10 to
20 mA / cm ² , pH 3.0, bath temperature 30 ° C.

On the other hand, Co, Mo, Cr, B, In and P
When at least one element of d is added, Co is 15
Wt% or less, Mo has a saturation magnetic flux density (B
It is desirable to keep _S ) at 1.5 T or more and to secure a specific resistance (ρ) of 40 μΩcm or more. CoS in case of Co in bath composition
O ₄ · 6H ₂ O and 100 g / l (Co ions at 21g / l)
Up to 4.8 g / l of Na ₂ MoO ₄ .2H ₂ O in the case of Mo
(Mo ions up to 1.9 g / l) is desirable. For example, instead of Mo, Cr [Cr ₂ (SO ₄ ) ₃ .18H
Almost the same results were obtained when ₂ O] was added. B,
For In and the like, the increase in specific resistance (ρ) was about 10%, and there was no significant effect. On the other hand, when Co is added, the specific resistance (ρ) of the film slightly decreases, but the saturation magnetic flux density (B _S ) becomes about 10
Therefore, it is desirable to share with Mo. Also, Co
Increases the anisotropic magnetic field (H _K ) of the film and is therefore preferred for stabilizing the magnetic properties.

When the content of Co exceeds 15% by weight, the saturation magnetic flux density (B _s ) of the film increases, but the specific resistance (ρ) becomes too small. The resistance (ρ) cannot be increased to a desired value. Therefore, the coercive force of the film becomes large, which is not preferable. In addition, Mo, Cr
In order to increase the specific resistance (ρ) to a desired value without increasing the coercive force of the film, the content is set to 3% by weight or less.

The same applies to the amounts of B, In, Pd and the like. The plating conditions in these cases are the same as those described above for Ni-Fe2.
It may be exactly the same as the original system.

Assuming that the high frequency loss (tan δ) of the magnetic film is caused only by the eddy current loss, it can be expressed as: tan δ = μ ″ / μ ′ = R / ωL = μ ₀ μπd ² f / Cρ (1) , Μ ′ and μ ″ are the real and imaginary parts of the complex permeability, respectively. C is a constant determined by the film shape, and μ ₀ is the magnetic permeability in vacuum. Equation (1) above
Thus, if the specific magnetic permeability μ, the film thickness d, and the specific resistance ρ inherent to the magnetic film are known, the eddy current loss tanδ with respect to the frequency f can be estimated. Since the change in the head efficiency (efficiency for inducing magnetic flux) with respect to the frequency is considered to be proportional to the change in the real part of the complex magnetic permeability, δ is calculated from equation (1), and by taking this cos component, The frequency dependence of the head efficiency can be obtained. That is, the head efficiency η at each frequency can be expressed by the following equation.

Η = cos [arctan (μ ₀ μπd ² f / Cρ)] (2) It is a value obtained from the specific permeability μ, the film thickness d, and the specific resistance ρ inherent in the magnetic film from the equation (2). By defining the value of μd ² / ρ, the head efficiency η at an arbitrary frequency f can be extrapolated.

With the above head, writing blur at the time of high frequency recording,
A high performance magnetic disk with a surface recording density of 500 Mb / in ² or more, a recording frequency of 45 MHz or more, and a media transfer speed of 15 MB / s or more by combining with a magnetic disk using a metal magnetic film having a coercive force of 2 kOe or more with small overwrite fluctuation. A device is obtained.

The data bus is connected to the I / O interface by a 2-byte wide Fast and Wide SCSI (Samll Computer Sys- tem).
When the I / O device is used, the data bus has a 2-byte width of Fast and Fast due to the relationship between the price of the I / O device and the transfer speed per magnetic disk device that constitutes the I / O device.
Up to 20M using Wide SCSI interface
Data transfer up to B / s becomes possible. In this case, if the transfer speed per magnetic disk device is 15 MB / s or more, the price of the input / output device can be reduced.

If the capacity per magnetic disk unit is 550 MB, it is possible to handle OS (Operation Software) such as Windows (registered trademark) and Workplace. To achieve this capacity with one 3.5-inch magnetic disk, the surface recording density at which data can be recorded is 500 Mb.
/ In ² or more.

[0044]

(Embodiment 1) FIGS. 1 and 2 show an overall view and a plan view of a magnetic disk drive which is an example of the present invention. The magnetic disk drive comprises a magnetic disk for recording information, a DC motor (not shown) for rotating the magnetic disk, a magnetic head for writing and reading information, and a magnetic disk for supporting the magnetic head. Positioning means of means for changing the position with respect to
And a voice coil motor 5, and an air filter 6 for keeping the inside of the apparatus clean. The actuator is
The voice coil motor includes a carriage 7, a rail 8, and a bearing 9. The voice coil motor includes a voice coil 10 and a magnet 11. These figures show an example in which eight magnetic disks are mounted on the same rotating shaft to increase the total storage capacity.

FIG. 3 is a front view of a magnetic recording / reproducing apparatus according to the present invention, and FIG. 4 is a plan view of the same. In the figure, 1
, A magnetic disk; 2, a magnetic head; 3, a gimbal support device; 4, a positioning device (actuator); The magnetic disk 1 is driven to rotate in the direction of arrow a by the rotation drive mechanism. The magnetic head 2 is supported by the supporting device 3, by the positioning device 4, on rotation diameter O _1, is positioned is driven in the direction of arrow b ₁ or b _2, in which the predetermined cylinder T ₁ through T _n, Magnetic recording and reproduction are performed.

The magnetic disk 1 has a surface roughness R _MAX of 100.
A medium having a good surface property of not more than {preferably not more than 50}. The magnetic disk 1 has a magnetic recording layer formed on the surface of a rigid substrate by a vacuum film forming method. The magnetic recording layer is γ-
It is formed as a magnetic thin film of Fe ₂ O ₃ or Co—Ni, Co—Cr or the like. Since the thickness of the magnetic recording layer formed by the vacuum film forming method is 0.5 μm or less, the surface properties of the rigid substrate are directly reflected as the surface properties of the recording layer. Therefore, a rigid substrate having a surface roughness R _MAX of 100 ° or less is used. As such a rigid substrate, a rigid substrate mainly composed of glass, chemically strengthened soda-aluminosilicate glass or ceramic is suitable.

The magnetic recording layer can be made of a magnetic iron oxide such as γ-Fe ₂ O ₃ or a magnetic nitride. When the magnetic layer is made of a metal, an alloy, or the like, it is desirable to provide an oxide layer or a nitride layer on the surface or to make the surface an oxide film. It is also desirable to use a carbon protective film. By doing so, the durability of the magnetic recording layer is improved, and damage to the magnetic disk 1 can be prevented even when recording / reproducing with an extremely low flying height or during contact, start, and stop. The oxide layer and the nitride layer can be formed by reactive sputtering, reactive evaporation, or the like. In addition, the oxide film forms the surface of the magnetic recording layer made of a metal or an alloy containing at least one of iron, cobalt, and nickel, such as Co-Ni or Co-Cr, by reactive plasma treatment or the like. It can be formed by intentionally oxidizing. The magnetic disk 1 may be either perpendicular recording in which the recording residual magnetization of the magnetic recording layer has a component perpendicular to the film surface as a main component, or in-plane recording in which the in-plane component is a main component. Although not shown, a lubricant may be applied to the surface of the magnetic recording layer.

FIGS. 5 and 6 are views showing the assembly structure of the magnetic head 2 and the gimbal support device 3. FIG. Magnetic head 2
The read / write element 22 is attached to the air outflow end side of a slider 25 made of a ceramic structure, and a load is applied to the surface 24 opposite to the floating surface 23 by the support device 3 driven by the positioning device 4. Support to allow pitch and roll movements. The read / write element 42 is a thin film element formed according to a process similar to the IC manufacturing technology.

The supporting device 3 includes a rigid arm 51 attached to the positioning device 4 and a support 37 made of an elastic metal thin film.
Is fixed by means of couplings 11 and 12, and a flexible member 36, which is also a thin metal plate, is attached to a free end at one end in the longitudinal direction of the support member 37.
6, the magnetic head 2 is attached to the lower surface (see FIGS. 3 and 4). The support 37 is a rigid arm 51
Is attached to the elastic spring portion 21, and the rigid beam portion 42 is formed by connecting to the elastic spring portion 41. The rigid beam portion 42 has flanges 42a and 42b formed on both sides by bending. The flexible body 36 connects the two outer flexible frames 31 and 32 extending substantially in parallel with the longitudinal axis of the support 37 and the outer flexible frames 31 and 32 at ends separated from the support 37. And a central tongue-shaped portion 3 extending from a substantially central portion of the horizontal frame 33 so as to be substantially parallel to the outer flexible frame portions 31 and 32 and having a free end at the tip.
4, and one end opposite to the direction in which the horizontal frame 33 is located is attached to the vicinity of the free end of the support 37 by welding or the like.

On the upper surface of the central tongue 34 of the flexible body 36,
For example, a hemispherical load projection 35 is provided, and the load projection 35 transmits a load from the free end of the support 37 to the central tongue 34. The surface 24 of the magnetic head 2 is fixed to the lower surface of the central tongue 34 by means such as bonding.

In this embodiment, the surface roughness R
Using the magnetic disk 1 having _MAX , the flying start flying height of the magnetic head 2 is set in the range of 0.01 μm to 0.04 μm. Of the read or write cylinder T ₁ through T _n provided in the magnetic disk 1, the flying height g of the magnetic head 2 at the innermost circumferential cylinder T _n, flying start flying height 0.01
The drive is performed by setting a value between μm and 0.04 μm and a value several times as large as that. The shape of the slider 21 constituting the magnetic head 2, the load applied to the magnetic head 2 from the support device 3, the number of rotations of the magnetic disk 1, and the like are set so as to obtain the above-mentioned flying height.

FIG. 7 is a perspective view of the negative pressure slider.

The load slider 70 has a negative pressure generating surface 73 surrounded by an air introducing surface 71 and two positive pressure generating surfaces 72, 72 for generating a levitation force, and further has an air introducing surface 71 and two positive pressure generating surfaces. At the boundary between the pressure generating surfaces 72, 72 and the negative pressure generating surface 73, a groove 74 having a larger step than the negative pressure generating surface 73 is formed. The air outflow end 75 has a thin-film magnetic head element 76 for recording and reproducing information on the magnetic disk.

When the negative pressure slider 70 flies, the air introduced from the air introduction surface 71 expands on the negative pressure generating surface 73. At this time, the air flows toward the groove 74, so that the air flows toward the groove 74. An air flow from the air introduction surface 71 to the air outflow end 75 also exists inside 74. Therefore,
Even when dust floating in the air when the negative pressure slider 70 floats is introduced from the air introduction surface 71, the dust is introduced into the groove 74 and is swept away by the flow of air inside the groove 74,
The air is discharged out of the negative pressure slider 70 from the air outflow end 78. Further, when the negative pressure slider 70 flies, since the air flow always exists inside the groove 4 and there is no stagnation or the like, dust does not aggregate.

FIG. 8 is a conceptual diagram of a recording / reproducing separation type head in which a recording head is formed. The recording / reproducing separation type head includes an inductive recording head and a reproducing head using the element of the present invention, and a shield part for preventing the reproducing head from being confused due to a leakage magnetic field. Here, the mounting with a recording head for horizontal magnetic recording is shown, but the magnetoresistive element of the present invention may be combined with a head for perpendicular magnetic recording and used for perpendicular recording. The head has a lower shield film 82, a magnetoresistive film 86 and an electrode 8 on a base 80.
5, a reproducing head composed of an upper shield film 81 and a recording head composed of a lower magnetic film 84, a coil 87, and an upper magnetic film 83 are formed. The head writes a signal on the recording medium and reads a signal from the recording medium.

By forming the sensing part of the reproducing head and the magnetic gap of the recording head in such a manner that they are superimposed on the same slider, they can be positioned simultaneously on the same track. This head was processed into a slider and mounted on a magnetic recording / reproducing apparatus.

In this embodiment, the upper and lower magnetic films of the inductive recording head were formed by the following method.

Ni ++ content: 16.7 g / l, Fe ++ content: 2.
In a plating bath containing 4 g / l and other ordinary stress relieving agents and surfactants, frame plating was performed under the conditions of pH: 3.0, plating current density: 15 mA / cm ^2.
An inductive thin film magnetic head having a lower magnetic core was manufactured. The track width is 4.0 μm and the gap length is 0.4 μm. The composition of this magnetic film was 42.4Ni-Fe (% by weight).
And the magnetic characteristics are such that the saturation magnetic flux density (B _S ) is 1.64.
T, hard axis coercive force (H _CH ) 0.5 Oe and specific resistance (ρ)
Was 48.1 μΩcm 2. An upper magnetic core 83, a lower magnetic core 84 also serving as an upper shield layer, and a coil 87. It has a magnetoresistive element 86 for reproduction, an electrode 85 for passing a sense current to the magnetoresistive element, a lower shield layer 82, and a slider 80.

FIG. 9 shows the performance (overwrite characteristics) of the recording head according to the present invention evaluated with such a configuration.
Excellent recording performance of about -50 dB was obtained even in a high frequency region of 40 MHz or more.

FIG. 10 shows the relationship between the hard-axis coercive force and the average crystal grain size of the magnetic film obtained by the plating method and the sputtering method obtained in this embodiment. It can be seen that a low coercive force of 1.0 Oe or less can be obtained.

Further, the lower magnetic film can be formed by electroplating in the same manner as described above by electroplating, using a Ni-Fe alloy thin film composed of 70 to 80% by weight of Ni and the balance Fe, or by sputtering this alloy thin film using an alloy target.

FIG. 11 is a sectional view of an inductive recording head according to the present invention, and FIG. 12 is a plan view thereof. This thin film head comprises an upper shield film 81 and the above-described magnetic film adhered thereon. It comprises a lower magnetic film 83 and an upper magnetic film 84. FIG. 11 is a sectional view taken along line AA of FIG.
A non-magnetic insulator 89 is deposited between the layers 83,84. A portion of the insulator defines a magnetic gap 88, which, for example, interacts in a transducing relationship with a magnetic medium placed in an air bearing relationship by known techniques. The support 80 is in the form of a slider having an air bearing surface (ABS), which is in close flying relationship with the rotating media of the disk during disk file operations.

The thin-film magnetic head has an upper 83 and a lower magnetic film 8.
4 has a back gap 90. The back gap 90 is separated from the magnetic gap by an intervening coil 87.

The continuous coil 87 is a layer formed on the lower magnetic layer 84 by plating, for example, and these are electromagnetically coupled. Coil 87 has an electrical contact 91 at the center of the coil buried with insulator 89, and also has a larger area as electrical contact 92 at the outer end of the coil. The contacts are connected to an external electric wire and a read / write signal processing head circuit (not shown).

In the present invention, the coil 87 made of a single layer has a slightly distorted elliptical shape, a portion having a small cross-sectional area is arranged closest to the magnetic gap, and the distance from the magnetic gap is Becomes larger, the cross-sectional area gradually increases.

The back gap 90 is the magnetic gap A
It is located relatively close to the BS.

However, the elliptical coil has a back gap 9
The coils are relatively densely packed between the zero and the magnetic gap 88, and the coil width or cross-sectional diameter is small in this area.
Further, a large cross-sectional diameter at the portion farthest from the magnetic gap results in a decrease in electrical resistance. Further, elliptical (elliptical) coils have no corners, sharp corners or edges, and have low resistance to current. In addition, the elliptical shape requires a smaller total length of the conductor than a rectangular or circular (annular) coil. As a result of these advantages, the overall resistance of the coil is relatively low, heat generation is small, and a suitable heat dissipation is obtained. Since the heat is reduced by a considerable amount, collapse, elongation and expansion of the thin film layer are prevented, and the cause of the ball tip protrusion at the ABS is eliminated.

An elliptical coil shape in which the change in width progresses almost uniformly can be attached by a conventional plating technique which is less expensive than sputtering, vapor deposition or the like. A coil having another shape, particularly an angular shape, tends to have a structure in which plating adhesion is uneven. The removal of corners and sharp edges places less mechanical stress on the resulting coil.

In this embodiment, a coil wound in a large number of turns is formed in a substantially elliptical shape between the magnetic cores, and the coil cross-sectional diameter gradually expands from the magnetic gap toward the back gap. Is reduced.

FIG. 13 is a conceptual diagram showing the configuration on the substrate surface of the magnetoresistive element of the present invention formed below the inductive head. The magnetoresistive effect film 110 is
A long strip having a width 143 of the element is formed on the surface 50 along the surface 163 facing the recording medium. This shape is defined by the direction 16 in which the magnetic field to be sensed by the magnetoresistive film 110 is applied.
There is an effect of giving an appropriate shape anisotropy in a direction perpendicular to 0. An electric current is applied to the magnetoresistive film 110 by an electrode 140 that is in electrical contact with the magnetoresistive film 110, and a magnetic field is applied to a magnetic field sensing portion having a width 141 in a direction parallel to the surface of the recording medium 191 and a width 142 in a direction perpendicular to the surface of the recording medium 191. The resulting resistance change is obtained as an output.

In this conceptual diagram, the end of the magnetoresistive effect element is exposed on the surface facing the recording medium, but a yoke-like soft magnetic material for guiding a magnetic field from the recording medium is arranged from the facing surface. When the magnetic element is magnetically coupled to the magnetoresistive effect element provided inside, the mechanical durability of the element increases. In particular, the M
By reducing the R height, the magnetic path resistance of the yoke can be reduced and the sensitivity can be improved.

The magnetoresistive effect element of the present invention is, for example, shown in FIG.
It has the following configuration. On the base 150, the magnetoresistive effect film 110, that is, the bias film 132, the magnetic film 111,
Nonmagnetic conductive film 120, magnetic film 112, nonmagnetic conductive film layer 1
20, the magnetic film layer 111 and the bias film 131 are laminated, and the electrode 140 is electrically connected. In the element configuration shown in FIG. 12, the electrode 140 is provided below the bias film 131. This is an example of a structure effective when an insulator such as nickel oxide is used for the upper bias film.

The electrode 140 may have another structure, for example, a bias film may be formed only partially and the electrode 140 may be formed thereon. Alternatively, a conductive bias film such as FeMn, Co
There is also a method in which an electrode is formed by using a Pt film or the like to directly adhere to the electrode.

This device has a magnetic film to which a strong anisotropy is applied by a bias film, and a uniaxial anisotropy, a shape anisotropy, or a soft film bias which is weaker than the aforementioned anisotropy. And a magnetic film applied by, for example, alternately laminating via a non-magnetic conductive film so that a current can be conducted but magnetic coupling does not occur. In particular, the application direction of the anisotropy will be described below.

FIG. 15 is a conceptual diagram showing an example of anisotropy control of the magnetoresistive element of the present invention, and is a perspective view of the element portion indicated by AA 'in FIG. Bias film 131 and
132 applies anisotropy due to exchange coupling in the directions of arrows 171 and 172 in the figure. In the figure, arrow 160 indicates the direction of the magnetic field to be sensed, and arrow 161 indicates the direction of unidirectional anisotropy induced in magnetic film 111. The direction of easy magnetization of the magnetic film 112 sandwiched between the nonmagnetic conductive films 120 is applied in the direction of arrow 162 in the figure by induction of uniaxial anisotropy. This is achieved by applying a magnetic field in a predetermined direction during the growth of the magnetic film. The embodiment of this figure is an example in which the application of anisotropy is realized by a bias film and induced magnetic anisotropy. As a result, the arrows 161 and 162 are both orthogonal to each other in the film plane. Compared with the magnitude of the magnetic field to be sensed, the magnetic film
By reducing the anisotropy of 12, the magnetization of the magnetic film 111 is substantially fixed to the external magnetic field, and only the magnetization of the magnetic film 112 responds greatly to the external magnetic field. Further, for the magnetic field to be sensed in the direction of arrow 160,
The magnetization of the magnetic film 111 is in an easy axis excitation state in which the magnetization and the external magnetic field are parallel due to the anisotropy 161, and is in a difficult axis excitation state in which the magnetization and the external magnetic field are perpendicular due to the anisotropy of the magnetic film 112. Has become. By this effect, the above response can be made more remarkable, and a state is realized in which the magnetization of the magnetic film 112 with respect to an external magnetic field is driven by hard axis excitation due to rotation starting from the direction of arrow 162. In addition, it is possible to prevent noise accompanying excitation due to domain wall movement, and to enable operation at a high frequency.

As another embodiment of the magnetoresistive element of this embodiment, an application of anisotropy is realized by two kinds of different bias films, that is, a hard magnetic film and an antiferromagnetic film. Substrate
An antiferromagnetic film 132, a magnetic film 111, a nonmagnetic film 120, a magnetic film 112, and a hard magnetic film 133 are stacked on 150, and electrodes are connected. The antiferromagnetic film 132 and the hard magnetic film 133 are separated from each other by a non-magnetic film.
2 and heat-treated or magnetized in a magnetic field in directions 172 and 173 parallel and perpendicular to the direction 160 of the magnetic field to be sensed to change the magnetization of the magnetic films 111 and 112 in the directions of arrows 161 and 162, respectively. Lead to.
For example, nickel oxide is used for the antiferromagnetic film, and cobalt platinum alloy is used for the hard magnetic film. The same effect is obtained even if the positions of the hard magnetic film and the antiferromagnetic film are reversed or the directions of induction of the respective magnetizations are reversed.

The film constituting the magnetoresistive effect element of this example was manufactured as follows using a high-frequency magnetron sputtering apparatus. In an atmosphere of 3 mTorr of argon, the following materials were sequentially laminated on a ceramic substrate having a thickness of 1 mm and a diameter of 3 inches and a Si single crystal substrate. Nickel oxide, cobalt, nickel-20 at% iron alloy, and copper targets were used as sputtering targets. For addition of cobalt into nickel-iron, a cobalt tip was placed on a nickel-20 at% iron alloy target. To add nickel and iron to cobalt, nickel and iron chips were arranged on a cobalt target. In the laminated film, high frequency power was applied to each of the cathodes on which the respective targets were arranged to generate plasma in the apparatus, and shutters arranged for the respective cathodes were opened and closed one by one to form layers sequentially. At the time of film formation, a magnetic field of about 50 Oe is applied in parallel to the substrate by using two pairs of electromagnets orthogonal to each other in the plane of the substrate to have uniaxial anisotropy and change the direction of the exchange coupling bias of the nickel oxide film in each direction. Guided in the direction.

The induction of anisotropy was performed by applying a magnetic field in the direction to be induced when forming each magnetic film by using two pairs of electromagnets mounted near the substrate. Alternatively, a heat treatment in a magnetic field is performed near the Neel temperature of the antiferromagnetic film after the formation of the multilayer film, and the direction of the antiferromagnetic bias is induced in the direction of the magnetic field.

The performance of the magnetoresistance effect element was evaluated by patterning the film into a strip shape and forming electrodes. At this time, the direction of the uniaxial anisotropy of the magnetic film was made parallel to the current direction of the element. The electric resistance is measured by applying a constant current between the electrode terminals and applying a magnetic field in the plane of the element in the direction perpendicular to the current direction. The electric resistance of the element is measured as the voltage between the electrode terminals and sensed as the magnetoresistance change rate. did.

In Table 1, the characteristics of the device are represented by the rate of change in resistance and the saturation magnetic field. The reproduced output as an element corresponds to the magnitude of the resistance change rate, and the sensitivity corresponds to the small saturation magnetic field.

As is clear from the results shown in Table 1, the magnetoresistive elements Nos. 1 to 5 in particular have a resistance change rate of 4% or more and have good magnetic properties. Excellent in rate. In particular, Samples Nos. 1, 2, and 4 show good magnetic field sensitivity of about 10 Oe and a high output of 6-7% in resistance change rate.

[0082]

[Table 1]

In the magnetic storage device of this embodiment,
The area sandwiched between the pair of electrodes 85 is the reproduction track width, which is 2 μm. At the time of recording, the number of turns is 20
A current of 15 mAop is applied to the coil 87 to record arbitrary information on the magnetic layer of the medium.
And a leakage magnetic field from the medium magnetic layer was detected.

This magnetic head was manufactured using a C head having a coercive force in the recording bit direction of 2100 Oersted and a coercive force orientation ratio of 1.2.
A magnetic storage device was constructed by combining with a 3.5-inch magnetic disk having oCrTa (the amount of Cr added was 16 atomic%) as a recording layer. The product Br · δ of the residual magnetic flux density and the film thickness of the magnetic disk recording layer used here is 10
0 Gauss · μm. Table 2 shows the specifications of the magnetic storage device according to the present embodiment.

[0085]

[Table 2]

(Example 2) FIG. 6 shows the relationship between the composition of the magnetic film plated by changing the metal ion concentration of the plating bath, that is, the amount of Ni ++ and the amount of Fe ++, the magnetic characteristics and the specific resistance (ρ). It is shown.

Ni ++ is NiCl ₂ .6H ₂ O and Fe ++ is F
Using the eSO ₄ · 7H ₂ O, and other conventional stress relaxing agent,
Surfactant was added. pH: 3.0, bath temperature: 30
C., plating current density: 15 mA / cm ² . The thickness is 3.0 μm.

When the Ni content of the film is in the range of 38 to 60% by weight, the saturation magnetic flux density (B _s ) is at least 1.5 T and the specific resistance (ρ) is at least 40 μΩcm.
Comparative saturated magnetic flux density in the permalloy film (B _S) in 1.5 above, the specific resistance ([rho) in it can be seen that excellent properties more than double. The hard axis coercive force (H _CH ) is 80Ni-Fe
It is as small as 1 Oe or less almost similarly to the permalloy film. The trends of the saturation magnetic flux density (B _S ) and the specific resistance (ρ) are almost the same as those of the bulk material, but the amount that decreases as the Ni content increases is small. This is because the crystal grain size is remarkably small at 40 to 80 ° as compared with the bulk material.

These characteristics did not change significantly even when the pH was changed to about 2.5 to 3.5 and the plating current density was changed to the range of 5 to 30 mA / cm ² . The bath temperature was also changed to the range of 25 to 35 ° C.
Only a slight increase in the i content did not affect the properties themselves.

The magnetic film in this embodiment is composed of an upper magnetic core of an inductive thin film magnetic head and Ni 70 to 8 below.
It is suitable for a combination using an Fe-Ni-based alloy containing 0% by weight, but can be used for both upper and lower magnetic cores.

In particular, as shown in FIG.
The highest value was 1.6 T in B _S by weight%, and the (N
Those having a combination of Ni and Fe having an (i / Fe) ratio of 0.667 to 1.00 are preferable. In addition, Ni38-60
The (Ni / Fe) ratio of the film in weight% is 0.613-1.
50.

Example 3 FIG. 17 shows (Ni 44% by weight)
It is a result of study on magnetic properties and specific resistance (ρ) of a magnetic film containing Mo in an Fe) -based alloy.

That is, the amount of Ni ++: 16.7 g / l, Fe ++
It shows the magnetic properties and the specific resistance (ρ) of the magnetic film when Mo is added as an element for increasing the specific resistance (ρ) to a plating bath containing the amount: 2.2 g / l. Mo is Na ₂
MoO ₄ · 4H ₂ O-added up to 5 g / l using. Mo
It can be seen that the specific resistance (ρ) of the magnetic film increases in proportion to the addition amount by adding. For example, when Mo: 2% by weight is added, the specific resistance (ρ) of the magnetic film is about 60 μΩcm or more, which is three times or more that of the 80Ni—Fe permalloy film. At that time, the saturation magnetic flux density (B _S ) is only about 1.50 T, a decrease of about 5%, and maintains a value of 1.5 times or more that of the 80Ni—Fe permalloy film. However, when the addition amount is 3% by weight or more (Mo is 5 g / l or more with Na ₂ MoO ₄ .4H ₂ O), the coercive force (H _CH ) becomes 1 Oe or more, and the saturation magnetic flux density (B _S ) becomes 1.5 T or less is not preferable.

The effect was almost the same as that of Mo, although Cr was examined instead of Mo.

The magnetic film in this embodiment can be used in the same manner as in the above embodiment.

(Example 4) FIG. 18 is a graph showing (Ni 44% by weight)
Fe) -Co 15 wt% -Mo The results of a study in the case where Co and Mo are added in the same manner in order to further increase the saturation magnetic flux density (B _S ) and the specific resistance (ρ) without impairing the magnetic properties of the magnetic film. . With CoSO ₄ · 7H ₂ O The addition of Co,
Mo was added in the same manner as in Example 3 using Na ₂ MoO ₄ .4H ₂ O. The addition amount of Co is 13 wt% (CoSO ₄ · 7H ₂ O
In this case, Mo was added up to 4% by weight. As a result, by adding 13% by weight of Co, the saturation magnetic flux density (B _s ) of the magnetic film is increased by about 10% to 1.78T, but the specific resistance (ρ) is reduced by about 30% to 35 μΩcm. . Therefore,
By adding Mo, the specific resistance (ρ) recovers,
With the addition of 2.5% by weight, the specific resistance (ρ) becomes about 55 μΩcm, and conversely shows an increase of about 20%. At that time, the saturation magnetic flux density (B _S ) is 1.55 T, which is higher than that of the film without Co. Further, the addition of Co increases the anisotropic magnetic field of the film, so that the magnetic properties are also stable.

The magnetic film in this embodiment can be applied in the same manner as described above.

(Example 5) FIG. 19 shows the frequency characteristics of the magnetic permeability (μ) of a typical magnetic film manufactured by the manufacturing method shown in Examples 2 to 4, and the μ characteristic of each 1 MHz was measured.
This is the result of standardization with the value of. 80Ni as a comparative sample
-Fe permalloy was also measured. All film thicknesses are 3
μm. 48 to 60 μΩ of specific resistance in the present embodiment
In the case of cm, the frequency (f) when the decrease of the magnetic permeability (μ) with respect to the frequency (f) is 25% (that is, 75% of the initial value) is 40 MHz to 70 MHz, and the permalloy 15M
It extends about 3 to 5 times compared to Hz, and it can be seen that the frequency characteristics are improved.

(Embodiment 6) FIGS. 20 and 21 are cross-sectional views of an induction type thin film magnetic head having a two-stage wound coil used for the upper and lower magnetic films as in the first embodiment as the magnetic film according to the present invention. is there.

As shown in FIG.
0 denotes two layers 21 of a magnetic material such as permalloy, for example.
2 and 214 including lower and upper magnetic films. Layers 212 and 214 are shaped layers 211 and 21 respectively.
3 in two stages.

These layers 212 and 214 are insulated except for the rear gap region 218 which is in physical contact and the tip region 219 which is separated by a thin film 220 of non-magnetic material to form a magnetic gap 221. Layers 215, 12
6 and 217. Magnetic layer 21
2 and 214 have flat conductive coils 222
Is provided. The coil 222 comprises a layer 215 of insulating material,
It has a plurality of turns 223a through 223n in two layers attached in an elliptical pattern between 216 and 217. The end of the transducing gap 221 coincides with the air bearing surface (ABS) formed on the non-magnetic substrate 224 to which the above-described layers are deposited. The conversion gap 221 is
A magnetic recording medium (not shown) such as a rotating magnetic disk
And air bearing relationships. As the disk rotates, its head flies over its air bearing surface (ABS) very close to the disk recording surface.

To manufacture this thin-film magnetic head, the magnetic layer 212 and the shaping layer 2 are formed on the substrate 224 using a suitable mask to provide a thin adhesion layer in the pole tip region 219.
11 is attached. A non-magnetic layer 220 is then deposited over layers 211 and 212 except for the back gap region 218. Then, a first insulating layer 215 is deposited over layer 220 except at magnetic gap 221. Elliptical spiral windings 223a through 223n of a first layer of continuous, flat conductor are deposited on insulating layer 215, for example, by electroplating. The insulating layer 216 is the first of the coil.
And a second layer winding of the coil is applied, and an insulating layer 217 is applied above the coil.
Then, as described above, except for the rear gap region 218 that is in physical contact with the magnetic layer 212,
14 is attached above the insulated coil.

The tip 219 of the pole piece has a pre-selected substantially constant width W. This width W is approximately the same as or slightly smaller than the width of the track on the corresponding rotatable magnetic medium. The selected width W of the pole tip is obtained by trimming the pole tip, the step of trimming the pole tip being performed before the step of depositing the shaping layer 213 for the second magnetic layer 214. Will be By changing the process in this way, it is possible to cut off the tip of the pole piece with much higher accuracy than the conventional process.

After attaching the magnetic layer 214 and the shaping layer 2
Before depositing 13, the thin film head assembly is covered with a photoresist mask 230. A window 232 is then formed in the photoresist mask on either side of the pole tip region 219 of the head.
The masked head undergoes an ion-milinda process. During that process, the unmasked portion of the head is etched away and the pole tip is cut to the desired width as shown in FIG.

The ion-milinda process has almost the same effect on the surface to be processed, which causes the unmasked head structure to be etched as well as the photoresist mask. This also causes the material etched from the head to be redeposited on the rest of the mask and on the head structure previously etched. For this reason, the ion milling process is performed in two stages. In the first step, the unmasked head structure is
Substrate 2 via non-magnetic gap layer 220 and magnetic layer 212
It is etched up to 24. To completely remove this material,
The first step is preferably performed to the extent that it etches too little into the substrate 224. A second step in this ion milling process is provided to remove any redeposited material, for example, from 75 degrees to vertical.
It is performed at a large angle such as 80 degrees. The preferred embodiment of the ion milling step provides an etch rate for permalloy magnetic material of about 550 ° per minute at a power density of about 2 watts per cubic centimeter. The photoresist is removed and a shaped magnetic layer 213 is deposited, completing the thin-film magnetic head.

The photoresist mask is etched during the ion milling step, and the thickness of the resist on top of the head is less than the thickness of the photoresist above the pole piece area due to the outer shape of the magnetic layer 214. Become.

The thin-film magnetic head manufactured according to the present invention has a yoke structure having a conversion (transducer) magnetic gap at one end and a rear gap region at the other end. The yoke structure has a magnetic gap and a rear gap region. The yoke structure having a conductive coil for urging the magnetic yoke, which is attached between them, is formed of two magnetic material layers.

A description will be given of a magnetic storage device constructed using the thin-film magnetic head manufactured in this embodiment. As described above, the magnetic disk drive according to this embodiment has a magnetic disk having an outer diameter of about 3.5 inches, a spindle for rotating the disk, a magnetic head positioning mechanism, and a housing. The magnetic head is a self-recording / reproducing head using an inductive element for recording / reproducing, and has a track width of 5.0 μm.
The upper and lower magnetic films of the head have a saturation magnetic flux density of 1.3.
Specific resistance ρ = 60μΩcm, relative magnetic permeability μ = 100 at Tesla
A (Ni 44 wt% -Fe) -2 wt% Mo alloy thin film having a thickness d = 3 μm is used, and the gap length is 0.4 μm. The magnetic pole of the head is made of a similar Ni-Fe alloy plated thin film having a saturation magnetic flux density of 1.6 T or Fe-
Co—Ni / Al ₂ O ₃ / Fe—Co—Ni multilayer film, Ni
-ZrO ₂ , Y ₂ O having a particle size of 2 to 3 nm in a Fe thin film
_{3, TiO 2, HfO 2,} Al 2 O 3, or even using a thin film or the like containing SiO ₂ can be obtained the same effect. When the oxide in the magnetic film is mixed, the particle diameter is desirably between 0.5 nm and 5 nm. This is because only the specific resistance of the magnetic film can be increased without significantly lowering the saturation magnetic flux density or the soft magnetic characteristics within the range of the particle size. In addition, by including the above-described oxide in the Fe—Ni alloy thin film, the specific resistance becomes about 60.
With the increase to μΩcm, the relative magnetic permeability is around 1000, showing good soft magnetic properties. On the other hand, oxide-free N
When an iFe thin film or the like is applied to the recording magnetic pole of the head,
By lowering the relative magnetic permeability to 500 or less, high-frequency characteristics can be improved. However, in this case, the recording magnetomotive force of the head must be set to 0.5 AT or more.

In the recording layer of the magnetic disk (11), CoCrTa having a coercive force in the recording bit direction of 2100 Oersted and a coercive force orientation ratio of 1.2 was added at an amount of 16 at.
%) Is used. The product Br · δ of the residual magnetic flux density and the film thickness in this magnetic disk is 300 Gauss · μm. By using this recording medium, it is possible to improve the linear recording density characteristics and to significantly reduce medium noise in a high linear recording density region. If the medium coercive force is 200 Oe or less, the bit error rate is reduced and the device cannot operate.

The rotational speed of the spindle at the time of recording / reproducing is set to 4490 rpm, and the flying height of the head at the outermost periphery of the data storage area on the magnetic disk at this time is 0.
05 μm. The recording frequency is set so that the linear recording density on each track is equal from the innermost circumference to the outermost circumference of the data storage area.
It is set to 5 MHz.

In the magnetic disk drive of this embodiment,
The linear recording density of data on each track is 144 kB
PI (k iro B it P er I nch), track density 5kTPI
(K ilo T rack P er I nch) is set to, surface recording density is 720 megabits per square inch. In this embodiment, four magnetic disks are used, the format capacity of the apparatus is 2.8 gigabytes, and the data transfer rate is 15 megabytes per second. In this embodiment, 8/9
Data is recorded using conversion.
Even if data is recorded using the seven methods, an apparatus having the same performance as that of the present embodiment can be configured. However, the recording frequency in this case is 45 MHz.

Table 3 shows the specifications of the magnetic storage device constructed according to this embodiment.

[0113]

[Table 3]

(Embodiment 7) Next, the results of constructing a magnetic storage device by combining magnetic disks having a disk diameter of 2.5 inches, 1.8 inches, and 1.3 inches with a magnetic head according to the present invention. State. The magnetic head and magnetic disk used in this embodiment are the same as those used in the sixth embodiment. The linear recording density of data on each track is 144 kBPI, and the track density is 5 kT.
Set to PI. Note that the spindle rotation speed was 15 MB / sec for each disk diameter.
It is set to be. Further, as described in the sixth embodiment, each device having the same performance as that of the present embodiment can be configured even if data is recorded using the conventional 1-7 system. However, the recording frequency in this case is 45
MHz. Tables 4 to 6 show the specifications of each device.

[0115]

[Table 4]

[0116]

[Table 5]

[0117]

[Table 6]

Example 8 Two types of inductive thin-film magnetic heads using magnetic poles having different specific resistances ρ, film thicknesses d and specific magnetic permeability μs were produced, and the frequency dependence of the recording magnetic field strength was measured by using an electron beam. It was measured using the tomography method. The magnetic pole material, magnetic pole thickness d, specific resistance ρ, and 1 for each prototype head
Table 7 shows the relative magnetic permeability μ in the low-frequency region below MHz.

The head A has a magnetic pole having a thickness of 3 μm according to the first embodiment.
The Ni—Fe alloy single layer film having the composition described in (1) is used. The head B was made of a 2.2 μm thick Fe
The -Co-Ni-Mo film is used magnetic poles laminated through an Al ₂ O ₃ intermediate layer having a thickness of 0.1 [mu] m. Therefore, the total magnetic pole film thickness of this head is 4.5 μm. Incidentally, Fe-Co-Ni-Mo / Al 2 O 3 / Fe-Co used here
When the thickness of one Fe—Co—Ni—Mo film is 2.7 μm or more, the recording frequency of the Ni—Mo multilayer film is 45 MHz.
The attenuation of the magnetic field intensity at z reaches 10% or more, which is undesirable because it causes the amount of bleeding and the overwrite film to fluctuate with the recording frequency. In this embodiment, Fe-Co-N
The thickness of one i-layer was set to 2.2 μm. On the other hand, the head C has a thickness of 3 μm and a specific resistance of 90 μm on the magnetic film below the magnetic pole.
A Co-Ta-Zr amorphous single layer film of μΩcm is used.

[0120]

[Table 7]

The head efficiency η was calculated from the measured result of the frequency dependence of the normalized recording magnetic field intensity. In the head A having the Ni-Fe single layer film as the magnetic pole, the recording magnetic field intensity decreases from about 10 MHz, and the intensity at 100 MHz is attenuated to 60% or less of the intensity in the low frequency region. On the other hand, the head B has the same magnetic permeability and specific resistance as Fe—C which is equivalent to that of the NiFe film used for the head A.
using o-Ni-Mo film, but the eddy current loss because of the multi-layered through the Al ₂ O ₃ insulating layer is greatly reduced. In the case of this head, the attenuation of the magnetic field intensity at 100 MHz is about 20%, and the frequency characteristic is improved. In addition, the head C has excellent frequency characteristics of almost zero attenuation of the magnetic field intensity even at 100 MHz.

Embodiment 9 In this embodiment, the upper and lower magnetic films were formed by the following manufacturing method.

Ni ++ content: 16.7 g / l, Fe ++ content: 2.
In a plating bath containing 4 g / l and other ordinary stress relieving agents and surfactants, frame plating was performed under the conditions of pH: 3.0, plating current density: 15 mA / cm ^2.
An inductive thin film magnetic head having a lower magnetic core was manufactured. The track width is 4.0 μm and the gap length is 0.4 μm. The composition of this magnetic film was 42.4Ni-Fe (% by weight).
And the magnetic characteristics are such that the saturation magnetic flux density (B _S ) is 1.64.
T, hard axis coercive force (H _CH ) 0.5 Oe and specific resistance (ρ)
Was 48.1 μΩcm 2.

FIG. 22 is a perspective view of a recording / reproducing separated thin film magnetic head, and FIG. 23 is a plan view of the recording head. Upper magnetic core 320, lower magnetic core also serving as upper shield layer
321 and a coil 325, and these three constitute a recording head. A slider 326 has an electrode 324 and a lower shield layer 322 for allowing a sense current to flow through the magnetoresistive element 323 for reproduction and the magnetoresistive element 323.
It has a configuration of

The inductive type thin film magnetic head was mounted on the magnetic disk device shown in Example 1, and the recording performance was evaluated.
The medium has an outer diameter of 3.5 inches and a coercive force of 2500 Oe.

The performance (overwrite characteristic) of the recording head according to the present invention evaluated in such a configuration was excellent in recording performance of about -50 dB even in a high frequency region of 40 MHz or more.

(Embodiment 10) In the magnetic storage device of this embodiment, a recording / reproducing separation head using an inductive recording head for recording and a magnetoresistive element (MR element) for reproduction shown in FIG. Is used. The upper magnetic film of the recording magnetic pole of the inductive head is formed as described above, and the upper shield layer 81 also serving as the other recording magnetic pole has a thickness of one Fe-Co-Ni film of 2.2 μm.
And the _{Fe-Co-Ni / Al 2} O 3 / Fe-Co-Ni
A multilayer film is used. The thickness of the Al ₂ O ₃ intermediate layer was 0.1 μm, and the track width of the recording pole was 3 μm. For the lower shield layer 82, a 1 μm thick Ni—Fe alloy was used. The magnetoresistive element 86 is made of a 15-nm-thick Ni—Fe alloy, and is driven using a soft film bias method. It should be noted that the magnetoresistive element 86 is made of Ni—Fe alloy instead of Ni—Fe alloy.
Layer, Cu layer, Co layer, and Ni-O system, Fe-Mn
Spin-valve type element made of an antiferromagnetic film based on Cr-based or Cr-Mn-based, or Co-Ag, Co-Au, Ni
Alloy-based giant magnetoresistive elements such as Fe-Ag, Co-Cu, Fe-Ag, or Co / Cr, Fe / Cr,
A Co / Cu or NiFe / Cu multilayer giant magnetoresistive element can also be used.

The magnetic storage device constructed according to the present embodiment can achieve the same specifications as in Table 2 described above.

[0129]

According to the present invention, a recording head medium transfer speed of at least 15 MB / s capable of sufficiently recording even in a high coercive force medium and in a high frequency region by a low-cost frame plating method with a specific composition. By rotating the magnetic disk at a recording frequency of 45 MHz or more and at a high speed of 4000 rpm or more, a high-density magnetic storage device capable of high-speed data transfer, reduced access time, and increased storage capacity can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic recording device.

FIG. 2 is a sectional view of a magnetic recording device.

FIG. 3 is a front view of the magnetic recording device.

FIG. 4 is a plan view of the magnetic recording device.

FIG. 5 is an assembly diagram of a magnetic head and a supporting device.

FIG. 6 is an assembly view of a magnetic head and a supporting device.

FIG. 7 is a perspective view of a slider provided with a thin-film magnetic head.

FIG. 8 is a perspective view of a read / write separated thin film magnetic head.

FIG. 9 is a diagram showing a relationship between frequency and overwriting.

FIG. 10 is a diagram showing a relationship between a crystal grain size and a coercive force in a hard axis direction.

FIG. 11 is a sectional view of an inductive thin film magnetic head.

FIG. 12 is a plan view of an inductive thin film magnetic head.

FIG. 13 is a plan view showing a film configuration of a magnetoresistive thin-film magnetic head.

FIG. 14 is a diagram showing a film configuration of a magnetoresistive head.

FIG. 15 is a diagram showing a film configuration of a magnetoresistive head.

FIG. 16 is a diagram showing the relationship between Ni amount or (Ni / Fe) ratio and B _s , ρ, and H _CH .

FIG. 17 is a diagram showing the relationship between the amount of Mo and B _S , ρ, and H _CH .

FIG. 18 is a diagram showing the relationship between the amount of Mo and B _S , ρ, and H _CH .

FIG. 19 is a diagram showing a relationship between frequency and (μf / μ1 MHz).

FIG. 20 is a plan view of the thin-film magnetic head.

FIG. 21 is a sectional view of a thin-film magnetic head.

FIG. 22 is a perspective view of a read / write separated thin film magnetic head.

FIG. 23 is a plan view of an inductive thin film magnetic head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic disk, 2 ... Thin film magnetic head, 3 ... Gimbal system support device, 4 ... Positioning device, 25 ... Slider, 80
... Base (slider), 81,321 ... Top shield film,
82, 322: lower shield film, 83, 320: upper magnetic film, 84: lower magnetic film, 85, 324: electrode, 86,
110,323 ... Magnetoresistance effect film, 87,222,32
5: coil, 88, 221: magnetic gap, 89: insulator, 90: back gap.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Shunichi Narumi             1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Takashi Kawabe             1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Moriaki Fuyama             1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor ▲ Taka ▼ Kimifumi No             1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Hisano Yamamoto             1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Kenzo Masuda             2880 Kozu, Odawara City, Kanagawa Pref.             Hitachi, Ltd. Storage Systems Division F-term (reference) 5D033 BA02 DA04 DA31

Claims (1)

[Claims] A lower magnetic film, one end of which is formed on the lower magnetic film and is in contact with one end of the lower magnetic film, and the other end of which is opposed to the other end of the lower magnetic film via a magnetic gap; A thin-film magnetic head comprising: an upper magnetic film that forms a magnetic circuit partially having a magnetic gap together with a lower magnetic film; and a conductor coil that forms a predetermined number of turns of a coil passing between the magnetic films and intersecting the magnetic circuit. In the manufacturing method, at least one of the lower and upper magnetic films may include a plating bath containing Ni ++ ions having a metal ion concentration of 15 to 20 g / l and Fe ++ ions having a metal ion concentration of 2.0 to 2.7 g / l, And N
i ++ ion to Fe ++ ion ratio (Ni ++ / Fe ++) of 7
And a thin film magnetic head formed by electroplating using an Ni-Fe alloy electroplating bath having a pH of 2.5 to 3.5, which comprises a stress relaxing agent and a surfactant. Production method.