JP2002057031A - Soft magnetic film, thin film magnetic head using the film, method of manufacturing the film, and method of manufacturing the magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in the conventional FeNi alloy which is not capable of meeting all requirements such as high saturation magnetic flux density, low stress, and low coercive force and not capable of manufacturing a thin film magnetic head that can cope with the future trend of increase in recording density. SOLUTION: A lower magnetic pole layer 19 and/or an upper magnetic pole layer 21 are formed of FeNi alloy film by plating. The FeNi alloy film contains 55 to below 75 mass% Fe preferably 68 to 80 mass% Fe, and furthermore 0.116 to below 0.140 mass% S or 0.125 to 0.132 mass% S. By this setup, a thin film magnetic head which is capable of coping properly with an increase in recording density and excellent in corrosion resistance can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a soft magnetic film made of an FeNi-based alloy, and more particularly to a soft magnetic film having a low stress, a low coercive force Hc, and a high saturation magnetic flux density Bs.

[0002]

2. Description of the Related Art A conventional soft magnetic film having a high saturation magnetic flux density has a composition ratio of Fe of about 55% by mass and a composition ratio of Ni of about 4%.
5 mass% FeNi-based alloy, and the saturation magnetic flux density B
s was about 1.6T.

[0003] The FeNi-based alloy is used, for example, for a core layer of a thin-film magnetic head. In order to cope with a higher recording density in the future, it is essential to increase the saturation magnetic flux density Bs of the core layer in order to increase the recording density, and the soft magnetic film used for the core layer has a higher density than before. Saturation magnetic flux density B
s was requested.

[0004]

The soft magnetic film made of a FeNi-based alloy can increase the saturation magnetic flux density Bs by increasing the composition ratio of Fe.

[0005] However, it has been found that in the soft magnetic film of the FeNi-based alloy, the saturation magnetic flux density Bs can be increased with an increase in the Fe composition ratio, but the stress increases. For example, when the composition ratio of Fe is 55% by mass, the stress of about 110 MPa
When the composition ratio becomes 68% by mass, it increases to about 190 MPa.

When such a high-stress soft magnetic film is used for the core layer of a thin-film magnetic head, the core layer 7 is easily peeled off, and the reliability of the thin-film magnetic head is low. In particular,
If the Fe composition ratio is 68% by mass or more, the saturation magnetic flux density Bs
1.8T or more, and in order to cope with a future increase in recording density, Fe having such a high saturation magnetic flux density Bs
Although it has been demanded that a Ni-based alloy can be used, a high saturation magnetic flux density Bs can be secured, but a very high stress is generated, so that it is difficult to use as a core layer. For example, 0.5
It is necessary to form a magnetic layer by plating in a very narrow track width space of less than μm square. In order to perform appropriate plating growth in such a narrow space, it is necessary to have a high stress as described above. As a result, film peeling appears remarkably, and a thin film magnetic head which can appropriately cope with narrowing of tracks cannot be manufactured with good reproducibility.

The stress of a soft magnetic film made of a NiFe alloy is
It is considered that the average crystal grain size of the soft magnetic film is decreased when it is large. The average crystal grain size of the soft magnetic film can be controlled by the conditions of the electrolytic plating step when forming the soft magnetic film by the electrolytic plating method.

However, if the average crystal grain size of the soft magnetic film is large, the coercive force Hc will increase. That is, it is considered that a trade-off relationship is established between the stress and the coercive force Hc.

FIG. 21 is a graph showing the relationship between the stress of the NiFe alloy and the coercive force Hc. All of the samples used in this experiment had a composition ratio of Fe of approximately 72% by mass.

As shown in FIG. 21, when the stress decreases, the coercive force Hc increases. The increase in the coercive force Hc has an adverse effect on soft magnetic characteristics such as the saturation magnetic flux density Bs and the anisotropic magnetic field Hk of the soft magnetic film, and the soft magnetic film is deteriorated. For this reason, the soft magnetic film used for the core layer of the thin-film magnetic head is required to have the lowest possible coercive force Hc.

As described above, as the recording density increases in the future, the soft magnetic film used as the core layer of the thin-film magnetic head must have a high saturation magnetic flux density Bs and low stress and coercive force Hc. However, conventionally, it has not been possible to produce an FeNi-based alloy satisfying all of them.

The present invention has been made to solve the above-mentioned conventional problems, and a soft magnetic film made of an FeNi-based alloy capable of realizing high saturation magnetic flux density Bs, low stress and low coercive force Hc, and this soft magnetic film It is an object of the present invention to provide a thin-film magnetic head using a film and capable of coping with high recording density.

Further, the present invention provides a method of adding a dicarboxylic acid to a plating bath and further improving the electrolytic plating method.
Provided are a method for manufacturing a soft magnetic film and a method for manufacturing the thin-film magnetic head, which can easily and reproducibly form an FeNi-based alloy having a high saturation magnetic flux density Bs and a low stress and a low coercive force Hc. It is intended to be.

[0014]

The soft magnetic film according to the present invention has the following characteristics.
Is a FeNi-based alloy containing S at a composition ratio of 0.1
More than 16% by mass and less than 0.140% by mass.

In such a soft magnetic film, the magnetism is borne by Ni and Fe, and the coercive force Hc and the stress are both reduced with an increase in the composition ratio of the element S. Magnetic characteristics can be compatible. The element S
As the composition ratio increases, the anisotropic magnetic field increases, so that the soft magnetic characteristics are improved.

On the other hand, in such a soft magnetic film, the saturation magnetic flux density Bs is not greatly affected by the composition ratio of the element S. Therefore, while maintaining a high saturation magnetic flux density Bs, low stress and excellent soft magnetic Characteristics.

When the composition ratio of the element S is 0.116% by mass or less, the coercive force Hc and the stress do not decrease, and when the composition ratio is 0.140% by mass or more, the surface roughness of the film surface becomes severe. . If the surface roughness is severe, for example, when the soft magnetic film is used as a core material of a thin film magnetic head, the thickness of the gap layer formed thereon cannot be kept constant, and the gap determined by the thickness of the gap layer It is not preferable because the length tends to fluctuate, a predetermined magnetic pole shape cannot be formed, and the corrosion resistance tends to decrease. Therefore, the surface roughness of the soft magnetic film needs to be as small as possible. According to the present invention, the center line average roughness Ra of the film surface of the soft magnetic film formed within the above composition range can be made approximately 200 ° or less, more preferably 80 ° or less.

In the present invention, the composition ratio of S in the soft magnetic film is preferably 0.126% by mass or more. In such a soft magnetic film, both the stress and the coercive force Hc can be effectively reduced.

Further, in the present invention, the composition ratio of S is 0.1.
It is preferable that the content be 125% by mass or more and 0.132% by mass or less. According to the experimental results described later, the stress can be reduced to approximately 160 MPa or less when the composition is within the above range. Further, the coercive force Hc in the direction of the hard axis is approximately 470 (A
/ M), the coercive force Hc in the easy axis direction is approximately 27
0 (A / m) or less. Thus, the stress and the coercive force can be more effectively reduced. It has been confirmed by experiments described below that the surface roughness can be appropriately reduced, and the center line average roughness Ra of the film surface of the soft magnetic film formed within the above composition range can be made approximately 80 ° or less. .

In the soft magnetic film according to the present invention, the composition ratio of Fe is preferably more than 55% by mass and 75% by mass or less.

One of the important characteristics required of the FeNi-based alloy is a high saturation magnetic flux density Bs. As described above, it has been found that the saturation magnetic flux density Bs of the FeNi-based alloy can be increased by increasing the composition ratio of Fe.

According to the present invention, a higher saturation magnetic flux density Bs can be obtained by increasing the Fe composition ratio to more than 55% by mass as compared with the conventional FeNi-based alloy in which the composition ratio of Fe is approximately 55% by mass. be able to. Moreover, in the present invention, a FeNi-based alloy having a low stress and a low coercive force Hc can be provided while maintaining the high saturation magnetic flux density Bs with the content of the element S described above. When the composition ratio of Fe is 75% by mass or less, an FeNi-based alloy having a predetermined composition ratio can be easily formed by plating by an electrolytic plating method using a pulse current described later.

The saturation magnetic flux density Bs can be increased to 1.6 T or more by increasing the Fe composition ratio to more than 55% by mass.

In the soft magnetic film of the present invention, the composition ratio of Fe is preferably 72% by mass or more. In such a soft magnetic film, the saturation magnetic flux density Bs exceeds 1.8 T, and depending on the composition ratio, a high saturation magnetic flux density Bs of 1.9 T or more can be obtained.

In the present invention, the composition ratio of Fe is 6
It is preferable that the content be 8% by mass or more and 80% by mass or less.

When the composition ratio of Fe is 68% by mass or more, the saturation magnetic flux density Bs can be made 1.8T or more.

According to the present invention, even when the element S having the above composition range is added to the FeNi-based alloy, the stress can be reduced by adding the element S while maintaining a high saturation magnetic flux density Bs of 1.8 T or more. An FeNi-based alloy having a low coercive force Hc can be provided.

However, when the Fe composition ratio is more than 80% by mass, the stress is increased even by the addition of the element S, and the film tends to peel off, which is not preferable. Further, when the Fe composition ratio is 80% by mass or more, the coercive force Hc increases with an increase in the crystal grain size, and the soft magnetic characteristics such as the saturation magnetic flux density Bs tend to decrease. It is set to 80% by mass or less.

The present invention also provides a thin film having a lower core layer made of a magnetic material, an upper core layer formed on the lower core layer via a magnetic gap, and a coil layer for applying a recording magnetic field to both core layers. In a magnetic head, at least one core layer is formed of the soft magnetic film described in any of the above.

In the present invention, it is preferable that a lower magnetic pole layer is formed so as to protrude on the lower core layer at a surface facing the recording medium, and the lower magnetic pole layer is formed of the soft magnetic film.

Further, according to the present invention, the lower core layer and the upper core layer are located between the lower core layer and the upper core layer, and have a width dimension in the track width direction shorter than the lower core layer and the upper core layer. A regulated magnetic pole portion, wherein the magnetic pole portion is
A lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer, or the magnetic pole portion includes an upper core layer and A continuous upper magnetic pole layer, and a gap layer located between the upper magnetic pole layer and the lower core layer, wherein the upper magnetic pole layer and / or the lower magnetic pole layer is any one of the soft magnetic layers described above. It is characterized by being formed of a film.

In the present invention, the upper magnetic pole layer is formed of the soft magnetic film, and the upper core layer formed on the upper magnetic pole layer is formed of a soft magnetic film having a lower saturation magnetic flux density Bs than the upper magnetic pole layer. It is preferable to be formed by.

In the present invention, at least a portion of the core layer adjacent to the magnetic gap is composed of two or more magnetic layers, or the pole layer is composed of two or more magnetic layers. It is preferable that a magnetic layer in contact with a magnetic gap is formed by the soft magnetic film.

At this time, it is preferable that the other magnetic layer other than the magnetic layer in contact with the magnetic gap layer is formed of a soft magnetic film having a lower saturation magnetic flux density Bs than the magnetic layer in contact with the magnetic gap layer.

The soft magnetic film of the present invention contains the element S in an amount of more than 0.116% by mass and less than 0.140% by mass, or 0.132% by mass or more and 0.132% by mass or more.
FeNi-based alloy containing element S of not more than mass%,
Further, by making Fe more than 55% by mass and less than 75% by mass, preferably 68% by mass or more and 80% by mass or less, low stress and low coercive force are maintained while maintaining a high saturation magnetic flux density Bs as compared with the conventional case. A soft magnetic film that can secure Hc can be obtained. Further, with this soft magnetic film, the surface roughness of the film surface can be reduced.

The structure of the thin-film magnetic head includes a structure in which an upper core layer is opposed to a lower core layer via a gap layer, and a structure in which the lower core layer and the lower core are developed so as to appropriately cope with high recording density. There are various structures such as a structure in which a magnetic pole layer for regulating the track width is provided between the layers, separately from the core layer. However, in order to cope with a high recording density, the track width Tw is set to 1.0.
μm or less, more preferably 0.5 μm or less. The magnetic layer formed in such an extremely narrow space not only has excellent soft magnetic characteristics such as high saturation magnetic flux density Bs but also low soft magnetic characteristics. Film characteristics such as reduction of stress and surface roughness are also indispensable factors.

Therefore, by using the FeNi-based alloy of the present invention having a high saturation magnetic flux density, a low stress and a small surface roughness as a core layer or a pole layer of a thin-film magnetic head, the core layer is formed. And the saturation magnetic flux density Bs of the pole layer
The core layer and the pole layer having a desired shape can be formed, and the thin-film magnetic head having excellent corrosion resistance can be reproducibly formed. It becomes possible to manufacture well.

The method for producing a soft magnetic film of the present invention
Is a method of forming a film of an FeNi-based alloy containing by electroplating, wherein a plating bath used in the electroplating step includes:
Soft magnetism containing Fe ions, Ni ions and S ions, and further adding a dicarboxylic acid to the plating bath so that the composition ratio of S exceeds 0.116% by mass and less than 0.140% by mass. The film is formed by plating.

As in the present invention, when dicarboxylic acid is added to the plating bath, the element S is easily taken into the soft magnetic film, and the composition ratio of the element S in the soft magnetic film is contained in a predetermined amount. It becomes possible.

In the present invention, the dicarboxylic acid is sodium tartrate, and the amount of the sodium tartrate is more than 37 mmol / L with respect to the entire plating bath.
And it is preferable to be less than 100 mmol / L.

In the present invention, when sodium tartrate is selected as the dicarboxylic acid, the composition ratio of S is 0.116 by adjusting the amount of the sodium tartrate to be in the above range.
FeN in excess of 0.1% by mass and less than 0.140% by mass
The i-type alloy can be plated with good reproducibility.

The amount of sodium tartrate was 100 mmol /
The reason for setting L or less is that when sodium tartrate is added any more, the surface roughness of the film surface of the FeNi-based alloy becomes severe and a predetermined magnetic pole shape cannot be formed.
This is because the corrosion resistance of the Ni-based alloy decreases. Experiments described later revealed that the center line average roughness Ra of the film surface could be made 200 ° or less by setting the amount of sodium tartrate to 100 mmol / L or less.

In the present invention, the dicarboxylic acid is sodium tartrate, and the addition amount of the sodium tartrate is more preferably from 62 mmol / L to 82 mmol / L based on the entire plating bath.

By adding the above sodium dicarboxylate, the composition range of the element S contained in the FeNi-based alloy can be reliably increased to more than 0.116% by mass and less than 0.140% by mass. In addition, F with small surface roughness of the film surface
An eNi-based alloy can be formed, and according to the present invention, the center line average roughness Ra of the film surface can be suppressed to 80 ° or less.

According to the addition amount of the dicarboxylic acid, the composition ratio of S is 0.125% by mass or more and 0.1% by mass.
It is also possible to form a soft magnetic film having a concentration of 32% by mass or less by plating.

In the present invention, it is preferable to mix saccharin sodium in the plating bath. It is considered that S contained in this saccharin sodium (C ₆ H ₄ CONNaSO ₂ ) is taken into the FeNi alloy by the addition of dicarboxylic acid.

In the present invention, it is preferable that the soft magnetic film is formed by electroplating using a pulse current.

In the electroplating method using a pulse current, for example, ON / OFF of a current control element is repeated, and a time for flowing a current and a blank time for not flowing a current are provided at the time of plating. By providing a time during which no current is supplied, the NiFe alloy film is formed by plating little by little, and the distribution of current density during plating is smaller than that of a conventional electrolytic plating method using a direct current. Can be alleviated. According to the electroplating method using a pulse current, the content of Fe contained in the soft magnetic film can be easily adjusted as compared with the electroplating method using a direct current, and the Fe content can be incorporated into the film more.

The present invention also provides a lower core layer made of a magnetic material, an upper core layer facing the lower core layer via a magnetic gap on the surface facing the recording medium, and a recording magnetic field is induced in both core layers. A method of manufacturing a thin-film magnetic head having a coil layer, wherein the upper core layer and / or the lower core layer is formed by plating with a soft magnetic film formed by the manufacturing method described above. is there.

In the present invention, it is preferable that a lower magnetic pole layer is formed on the lower core layer so as to protrude from the surface facing the recording medium, and that the lower magnetic pole layer is formed by plating with the soft magnetic film.

According to the present invention, there is also provided a lower core layer and an upper core layer, wherein the width dimension between the lower core layer and the upper core layer in the track width direction is shorter than the lower core layer and the upper core layer. Having a regulated magnetic pole portion, wherein the magnetic pole portion is
A lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer; or A continuous upper magnetic pole layer and a gap layer located between the upper magnetic pole layer and the lower core layer, wherein the upper magnetic pole layer and / or the lower magnetic pole layer are formed by the manufacturing method described above. Characterized by being formed by plating with a soft magnetic film.

In the present invention, the upper magnetic pole layer is formed by plating with the soft magnetic film, and the upper core layer formed on the upper magnetic pole layer is formed of a soft magnetic material having a lower saturation magnetic flux density Bs than the upper magnetic pole layer. It is preferable to form the magnetic film.

In the present invention, at least a portion of the core layer adjacent to the magnetic gap is formed of two or more magnetic layers, or the pole layer is formed of two or more magnetic layers,
A magnetic layer in contact with the magnetic gap among the magnetic layers,
It is preferable that the soft magnetic film is formed by plating.

In the present invention, it is preferable that the other magnetic layers other than the magnetic layer in contact with the magnetic gap layer are formed of a soft magnetic film having a lower saturation magnetic flux density Bs than the magnetic layer in contact with the magnetic gap layer.

As described above, according to the method for producing a soft magnetic film of the present invention, by adding dicarboxylic acid to the plating bath, the element S can be easily taken into the FeNi-based alloy, and the high saturation magnetic flux density can be obtained. A soft magnetic film having Bs, low stress and low coercive force Hc, and further having a small surface roughness can be formed with good reproducibility.

The soft magnetic film of the present invention is formed by plating as a core layer or a pole layer of a thin-film magnetic head by using this manufacturing method, so that the soft magnetic film has a high saturation magnetic flux density Bs, low stress and low stress. With the magnetic force Hc, a core layer and a pole layer having a smaller surface roughness can be formed with good reproducibility, and a thin-film magnetic head excellent in high recording density can be easily manufactured.

[0057]

BEST MODE FOR CARRYING OUT THE INVENTION A soft magnetic film according to an embodiment of the present invention is a FeNi-based alloy, which contains S in addition to Fe and Ni.

According to the present invention, an FeNi-based alloy having a high saturation magnetic flux density Bs and a low stress and low coercive force Hc can be formed. Further, the surface roughness of the film surface can be reduced.

Fe is an important magnetic element mainly for improving the saturation magnetic flux density Bs. The saturation magnetic flux density Bs can be improved as the amount of Fe increases.

Conventionally, the amount of Fe was about 55% by mass, but in the present invention, the amount of Fe is set to be more than 55% by mass and less than 75% by mass.

The saturation magnetic flux density Bs can be increased to 1.6 T or more by increasing the amount of Fe to more than 55% by mass. Also, by the electrolytic plating method using a pulse current described later,
The amount can be easily adjusted to less than 75% by weight.

In the present invention, the composition ratio of Fe is 72
It is preferable that the amount is at least mass%. Thereby, the saturation magnetic flux density Bs can be set to 1.8T or more.

In the present invention, more preferably, the Fe
Is in the range of 68% by mass or more and 80% by mass or less. When the composition ratio of Fe is 68% by mass or more, the saturation magnetic flux density Bs can be 1.8T or more. In the present invention, the saturation magnetic flux density Bs is set to 1.
It is possible to improve the temperature to 9T or more, or to about 2.0T.

However, the Fe composition ratio is preferably 80% by mass or less, and it has been confirmed by an experiment described later that when the Fe content is larger than this, the stress increases and film peeling occurs. Also, there is a problem that the soft magnetic characteristics are deteriorated due to the increase of the coercive force Hc due to the coarsening of the crystal grain size. Therefore, in the present invention, the composition ratio of Fe is set to 80% by mass or less.

In the present invention, FeN containing the above-mentioned Fe amount is used.
i-based alloy, while maintaining high saturation magnetic flux density Bs
The composition ratio of the element S was set as follows in order to improve the increase in stress and the increase in coercive force Hc, which are regarded as problems due to an increase in the Fe amount.

First, in the present invention, the composition ratio of S is 0.1
It is preferably more than 16% by mass and less than 0.140% by mass. According to the experimental results described later, the same F
e, but the stress can be reduced as compared with the soft magnetic film in which the S composition ratio is smaller than that of the present invention, and the coercive force H
It was found that c could be reduced. According to the present invention, the stress can be suppressed to 200 MPa or less. The coercive force Hc in the direction of the hard axis is about 600 (A
/ M), the coercive force Hc in the easy axis direction is about 400
(A / m) or less.

In the present invention, the composition ratio of S is 0.1
It is preferably at least 26% by mass. This makes it possible to more appropriately reduce the stress and the coercive force Hc. Specifically, the stress was approximately 160 (A /
m) Hereinafter, the coercive force Hc in the direction of the hard axis is approximately 470.
(A / m) Hereinafter, the coercive force Hc in the easy axis direction is approximately 2
70 (A / m) or less.

In the present invention, more preferably, the composition ratio of S is set to be 0.125% by mass or more and 0.132% by mass or less. This makes it possible to more appropriately reduce the stress and the coercive force Hc. Specifically, the stress is about 160 (A / m) or less, the coercive force Hc in the hard axis direction is about 470 (A / m) or less, and the coercive force Hc in the easy axis direction is about 270 (A / m). It can be suppressed to the following.

The element S can be contained in the above composition ratio by adding a dicarboxylic acid to the plating bath as described later. It is known from experiments described later that the composition ratio of the element S increases as the amount of the dicarboxylic acid increases.

However, it was found that when the amount of the dicarboxylic acid added was too large, the surface roughness of the film surface became severe. It is preferable that the surface roughness of the film surface is as small as possible.
In particular, when the above-mentioned FeNi-based alloy is used as the thin-film magnetic head, if the surface roughness of the FeNi-based alloy film is severe, the layer formed thereon has an appropriate shape due to the influence of the surface roughness. Therefore, it is not possible to form a laminated film having a predetermined shape and characteristics, and there is a concern that corrosion resistance may be reduced.

Therefore, it is preferable to make the surface roughness of the film surface as small as possible. When sodium tartrate is used as the dicarboxylic acid as described later, the amount of the sodium tartrate added is 37 mm with respect to the entire plating bath.
ol / L and less than 100 mmol / L. Thereby, the composition ratio of the element S contained in the FeNi-based alloy becomes less than 0.140% by mass, and at this time, the center line average roughness Ra of the film surface can be suppressed to 200 ° or less.

More preferably, the addition amount of the sodium tartrate is set to 62 mmol / L or more and 82 mmol / L or less with respect to the entire plating bath, whereby the content of the element S is more reliably reduced to 0%. .116% by mass
More than 0.140 mass%, and the center line average roughness Ra of the film surface can be suppressed to 80 ° or less.

With the above-mentioned amount of sodium tartrate, the composition ratio of the element S contained in the FeNi-based alloy can be within the range of 0.125% by mass or more and 0.132% by mass or less. . Further, the center line average roughness Ra of the film surface can be suppressed to 80 ° or less.

However, it is considered that the center line average roughness Ra of the film surface is affected not only by the S content but also by the Fe content, and in the present invention, the Fe content is more than 55% by mass and 75% by mass.
Less than 8% by mass, more preferably at least 68% by mass.
It is considered that by setting the content to 0% by mass or less, the center line average roughness Ra of 200 ° or less, preferably 80 ° or less can be secured.

In the above-mentioned FeNi-based alloy, the element S
It has been confirmed that the element C is also contained in addition to.

An example of the FeNi-based alloy film according to the present invention will be disclosed below. The film thickness is about 2 μm, the composition ratio of Fe is about 72% by mass, the composition ratio of Ni is about 27% by mass, the composition ratio of S is 0.125 to 0.132% by mass, and the balance is C
It is. These composition ratios are the results of composition analysis by EPMA.

The coercive force Hc and the stress of this soft magnetic film decrease with an increase in the composition ratio of S, so that the coercive force Hc (in the direction of the hard axis) is approximately 480 A / m or less and the stress (4 inch Si). (Measurement by warpage of substrate) is approximately 160M
Pa or less. Further, the anisotropic magnetic field increases with an increase in the composition ratio of S, and is 210 A / m or more.

The soft magnetic film has a high saturation magnetic flux density B
In order to obtain s, the composition ratio of Fe is as high as 72% by mass. The saturation magnetic flux density Bs is maintained at about 1.9 T without being greatly affected by the composition ratio of S.

The specific resistance of the soft magnetic film is not greatly affected by the composition ratio of S, and is maintained at about 32 μΩ · cm.

The FeNi-based alloy according to the present invention described above is used as a core layer or a pole layer of a thin film magnetic head described below.

As shown in FIG. 1, for example, a thin-film magnetic head mounted on a hard magnetic disk device or the like includes a reproducing head h1 and a recording head h2 (inductive head).
The reproducing head portion h1 is formed on one end surface 1a of the slider 1 via a base layer 15 of alumina or the like.
A lower shield layer 2 made of a base alloy, a lower gap layer 3 made of alumina or the like and covering the lower shield layer 2, and an anisotropic magnetoresistive effect (AM) formed on the lower gap layer 3.
R effect), giant magnetoresistive effect (GMR effect), or tunnel type magnetoresistive effect (TMR effect), a magnetoresistive effect element 4, an electrode layer 5 electrically connected to the magnetoresistive effect element 4, It comprises an upper gap layer 6 made of alumina or the like and covering the magnetoresistive element 4 and the electrode layer 5, and an upper shield layer 7 formed on the upper gap layer 6.

The recording head h on the reproducing head h1
Reference numeral 2 denotes a soft magnetic film made of an FeNi-based alloy in which the lower core layer 7 is also used as the upper shield layer 7 of the reproducing head h1, and is made of a non-magnetic material such as alumina or SiO _2. , A coil layer 9 made of a good conductive material such as Cu and patterned on the gap layer 8, and an insulating layer 11 such as a resist applied on the coil layer 9. Upper core layer 10,
The upper core layer 10, like the lower core layer 7, is a soft magnetic film made of an FeNi-based alloy. Base end 1 of upper core layer 10
0a is magnetically connected to the lower core layer also serving as the upper shield layer 7, and the lower core layer 7 and the upper core layer 10 sandwich the gap layer 8 on the magnetic disk facing surface 1b side. The interval at which this occurs is the write gap G.

A protective film 16 made of carbon is formed on the magnetic disk facing surface 1b side of such a thin film magnetic head, and the upper core layer 10 and the lower core layer 7
Covered by

Next, driving of the thin-film magnetic head of the present invention will be described. When the thin-film magnetic head is driven, a recording current is applied to the coil layer 9, and the recording current causes the upper core layer 10 to be driven.
Then, a recording magnetic field is induced in the lower core layer 7. At this time,
Since the recording magnetic field penetrates through the upper core layer 10 and the lower core layer 7 in the hard axis direction, the upper core layer 10 and the lower core layer 7
The soft magnetic film has magnetic properties in the hard axis direction.

The recording magnetic field guided to the upper core layer 10 and the lower core layer 7 becomes a leakage magnetic field between the write gaps G, and magnetic recording is applied to the recording medium by the leakage magnetic field.

In such a thin film magnetic head, since the upper core layer 10 and the lower core layer 7 have a high saturation magnetic flux density Bs, it is possible to cope with a high recording density. In order to cope with a high recording frequency, it is necessary that the upper core layer 10 and the lower core layer 7 have high specific resistance and suppress eddy current loss. The resistance is
High recording frequency characteristics can be maintained as in the prior art.

The upper core layer 10 and the lower core layer 7
It is formed of the FeNi-based alloy soft magnetic film described above.

According to the present invention, the FeNi alloy has an element S content of more than 0.116% by mass and less than 0.140% by mass, or 0.125% by mass or more and 0.132% by mass or less. And more than 55% by mass and
It contains less than 5% by mass, preferably 68% by mass or more and 80% by mass or less of Fe.

According to the FeNi-based alloy, the saturation magnetic flux density Bs can be increased to 1.6 T or more, preferably 1.8 T or more, and the same Fe content is included, but the S composition ratio is lower than that of the present invention. Compared with a low soft magnetic film, the stress can be reduced and the coercive force Hc can be reduced. Coercive force Hc
Affects soft magnetic characteristics such as saturation magnetic flux density Bs and anisotropic magnetic field, and the soft magnetic characteristics can be improved as the coercive force Hc decreases. Further, the surface roughness of the film surface is small.

Since the above-mentioned FeNi-based alloy has a high saturation magnetic flux density Bs and is also excellent in other soft magnetic properties, by using the FeNi-based alloy for the lower core layer 7 and the upper core layer 10, It is possible to improve the recording density by concentrating the magnetic flux in the vicinity of the gap of the core layer, and it is possible to manufacture a thin-film magnetic head that can cope with a higher recording density in the future.

Further, since the core layer has a low stress and a small surface roughness, the core layer can be appropriately removed without peeling off the core layer when the core layer is formed. It can be formed in close contact with upper and lower layers.

Further, since the surface roughness of the film surface is small, it is excellent in corrosion resistance. For example, when the above-mentioned FeNi-based alloy is used for the lower core layer 7, the gap layer 8 having a very small thickness is formed thereon. It is easy to form with a predetermined thickness, and the gap length G determined by the interval between the lower core layer 7 and the upper core layer 10 can be formed with a predetermined length with good reproducibility.

In the above description, the thin-film magnetic head of the present invention has been described as a composite thin-film magnetic head, but it may be a thin-film magnetic head for recording only having a recording head.
In the above embodiment, both the upper core layer 10 and the lower core layer 7 are the soft magnetic films of the present invention, but either the upper core layer 10 or the lower core layer 7 is the soft magnetic film of the present invention. Any film is acceptable.

In the present invention, the soft magnetic film of the FeNi-based alloy according to the present invention can be used for a thin film magnetic head other than the structure shown in FIG. The structure of another thin-film magnetic head according to the present invention will be described below.

FIG. 2 is a partial front view of another thin-film magnetic head according to the present invention, and FIG. 3 is a partial longitudinal sectional view of the thin-film magnetic head shown in FIG.

The structure of the reproducing head h1 is the same as that of FIG. In the embodiment shown in FIGS. 2 and 3, the upper shield layer 7 is also used as the lower core layer of the recording head portion h2, as in FIG. The layer 17 is formed, and the gap depth (Gd) is regulated by the length from the surface facing the recording medium to the tip of the Gd determining layer 17. The Gd determining layer 17 is formed of, for example, an organic insulating material.

As shown in FIG. 2, the upper surface 7a of the lower core layer 7 is formed as an inclined surface which is inclined toward the lower surface as the distance from the base end of the magnetic pole portion 18 in the track width direction (X direction in the drawing) increases. Thus, it is possible to suppress the occurrence of side fringing.

As shown in FIG. 3, a magnetic pole portion 18 is formed from the surface facing the recording medium to the Gd determining layer 17.

The magnetic pole portion 18 includes a lower magnetic pole layer 19 from below,
A non-magnetic gap layer 20 and an upper magnetic pole layer 21 are stacked.

The lower magnetic pole layer 19 is formed by plating directly on the lower core layer 7. The gap layer 20 formed on the lower magnetic pole layer 19 is preferably formed of a non-magnetic metal material that can be plated. Specifically, NiP, NiPd, NiW, NiMo, Au, P
It is preferably selected from one or more of t, Rh, Pd, Ru, and Cr.

As a specific embodiment of the present invention, NiP is used for the gap layer 20. NiP
This is because the gap layer 20 can be appropriately brought into a non-magnetic state by forming the gap layer 20 in this manner.

Further, the upper magnetic pole layer 21 formed on the gap layer 20 has the upper core layer 2 formed thereon.
2 is magnetically connected.

As described above, when the gap layer 20 is formed of a non-magnetic metal material which can be formed by plating, the lower magnetic pole layer 1
9, the gap layer 20 and the upper magnetic pole layer 21 can be formed by continuous plating.

The magnetic pole portion 18 may be composed of two layers, a gap layer 20 and an upper magnetic pole layer 21.

As shown in FIG. 2, the magnetic pole portion 18 has a track width Tw in the track width direction (X direction in the drawing).

As shown in FIG. 2 and FIG.
An insulating layer 23 made of, for example, an inorganic insulating material is formed on both sides in the track width direction (X direction in the drawing) and behind the height direction (Y direction in the drawing). The upper surface of the insulating layer 23 is flush with the upper surface of the magnetic pole portion 18.

As shown in FIG. 3, a coil layer 24 is spirally patterned on the insulating layer 23. The coil layer 24 is covered with an insulating layer 25 made of an organic insulating material. The coil layer 24 may have a configuration in which two or more layers are stacked with an insulating layer interposed therebetween.

As shown in FIG. 3, the upper core layer 22 is patterned from the magnetic pole part 18 to the insulating layer 25 by, for example, a frame plating method. As shown in FIG. 2, the leading end 22a of the upper core layer 22 has a width T1 in the track width direction on the surface facing the recording medium, and the width T1 is larger than the track width Tw. Have been.

As shown in FIG. 3, the upper core layer 2
The base end 22b of the second 2 is directly connected to a connection layer (back gap layer) 26 made of a magnetic material and formed on the lower core layer 7.

In the present invention, the upper magnetic pole layer 21 and / or the lower magnetic pole layer 19 are formed of the FeNi alloy according to the present invention.

In the present invention, the FeNi-based alloy includes:
More than 0.116% by mass and less than 0.140% by mass or 0.125% by mass or more and 0.132% by mass
Contains the following element S, exceeds 55% by mass, and
Less than 80% by weight, preferably less than 68% by weight
It contains the following Fe.

According to the FeNi-based alloy, the saturation magnetic flux density Bs can be increased to 1.6 T or more, preferably 1.8 T or more, and the same Fe content is included, but the S composition ratio is lower than that of the present invention. Compared with a low soft magnetic film, the stress can be reduced and the coercive force Hc can be reduced. Coercive force Hc
Affects the soft magnetic properties such as the saturation magnetic flux density Bs and the anisotropic magnetic field, and the soft magnetic properties can be improved as the coercive force Hc decreases. Further, the surface roughness of the film surface is small.

Therefore, the FeNi-based alloy was added to the pole layer 19,
By using the magnetic pole layer 21 for the magnetic pole layer 19 formed in a very narrow space, a thin film magnetic head having excellent recording density can be formed with good reproducibility, and the surface roughness is small and the stress is low. 21 can be formed in a predetermined magnetic pole shape, and can be excellent in corrosion resistance.

FIG. 4 is a partial front view showing the structure of a thin-film magnetic head according to another embodiment of the present invention, and FIG. 5 is a vertical sectional view of the thin-film magnetic head taken along a dashed line shown in FIG. It is.

In this embodiment, the structure of the reproducing head h1 is the same as that shown in FIGS.

As shown in FIG. 4, an insulating layer 31 made of, for example, an inorganic insulating material is formed on the lower core layer 7. In the insulating layer 31, a track width forming groove 31a having a predetermined length is formed rearward in the height direction (Y direction in the drawing) from the surface facing the recording medium. The track width forming groove 31a is formed with a track width Tw on the surface facing the recording medium (see FIG. 4).

In the track width forming groove 31a, a magnetic pole portion 30 in which a lower magnetic pole layer 32, a nonmagnetic gap layer 33, and an upper magnetic pole layer 34 are laminated from below is formed.

The lower magnetic pole layer 32 is formed by plating directly on the lower core layer 7. The gap layer 33 formed on the lower magnetic pole layer 32 is preferably formed of a non-magnetic metal material which can be formed by plating. Specifically, NiP, NiPd, NiW, NiMo, Au, P
It is preferably selected from one or more of t, Rh, Pd, Ru, and Cr.

As a specific embodiment of the present invention, NiP is used for the gap layer 33. NiP
This is because the gap layer 33 can be appropriately brought into a non-magnetic state by forming the gap layer 33.

The magnetic pole portion 30 may be composed of two layers, a gap layer 33 and an upper magnetic pole layer 34.

On the gap layer 33, a Gd determining layer 37 is formed from a position away from the surface facing the recording medium by a gap depth (Gd) onto the insulating layer 31. The Gd determining layer 37 is formed of, for example, an organic insulating material.

Further, the upper magnetic pole layer 34 formed on the gap layer 33 is formed on the upper core layer 4 formed thereon.
0 and magnetically connected.

When the gap layer 33 is formed of a non-magnetic metal material which can be formed by plating as described above, the lower magnetic pole layer 3
2. The gap layer 33 and the upper pole layer 34 can be formed by continuous plating.

As shown in FIG. 5, a coil layer 38 is spirally patterned on the insulating layer 31. The coil layer 38 is made of an insulating layer 3 made of an organic insulating material or the like.
9.

As shown in FIG. 4, the track width forming groove 31 is formed.
On both end surfaces in the track width direction (X direction in the drawing), a slope 31c whose width dimension gradually increases from the upper surface of the upper magnetic pole layer 34 to the upper surface 31b of the insulating layer 31 in a direction away from the lower core layer 7 is formed. , 31c are formed.

As shown in FIG. 4, the tip portion 40a of the upper core layer 40 is formed in a direction away from the lower core layer 7 from the upper surface of the upper magnetic pole layer 34 to the inclined surfaces 31c, 31c.

As shown in FIG. 5, the upper core layer 40
The base end portion 40b of the upper core layer 40 is formed directly on the lower core layer 7 from the surface facing the recording medium in the height direction (Y direction in the drawing).

In the embodiment shown in FIGS. 4 and 5, the lower magnetic pole layer 32 and / or the upper magnetic pole layer 34 are formed of the FeNi-based alloy soft magnetic film of the present invention.

In the present invention, the FeNi-based alloy includes:
More than 0.116% by mass and less than 0.140% by mass or 0.125% by mass or more and 0.132% by mass
Contains the following element S, exceeds 55% by mass, and
Less than 80% by weight, preferably less than 68% by weight
It contains the following Fe.

According to the FeNi-based alloy, the saturation magnetic flux density Bs can be increased to 1.6 T or more, preferably 1.8 T or more, and the same Fe content is included, but the S composition ratio is lower than that of the present invention. Compared with a low soft magnetic film, the stress can be reduced and the coercive force Hc can be reduced. Coercive force Hc
Affects soft magnetic characteristics such as saturation magnetic flux density Bs and anisotropic magnetic field, and the soft magnetic characteristics can be improved as the coercive force Hc decreases. Further, the surface roughness of the film surface is small.

Therefore, the FeNi-based alloy was used as the magnetic pole layer 32,
34, a thin-film magnetic head excellent in high recording density can be formed with good reproducibility, and since the surface roughness is small and the stress is low, the pole layer 19 formed in a very narrow space can be formed. 21 can be formed in a predetermined magnetic pole shape, and can be excellent in corrosion resistance.

Further, according to the present invention, the lower magnetic pole layers 19, 32 and / or the upper magnetic pole layers 21, shown in FIGS.
34 may be configured by laminating two or more magnetic layers. In the case of such a configuration, it is preferable that the magnetic layer in contact with the gap layers 20 and 33 be formed of the FeNi-based alloy according to the present invention. Also, in particular, the gap layers 20, 33
The magnetic layer on the side in contact with
It is formed of a FeNi-based alloy containing less than 0.116% by mass of Fe and more than 0.116% by mass and less than 0.140% by mass, or containing 0.125% by mass or more and 0.132% by mass or less of S. Is preferred. As a result, the magnetic flux can be more concentrated in the vicinity of the gap, and a thin-film magnetic head capable of coping with a higher recording density in the future can be manufactured.
It is possible to form a pole layer of a predetermined shape with good reproducibility without causing film peeling or the like.

The magnetic layers other than the magnetic layers in contact with the gap layers 20 and 33 may be made of a magnetic material of any material and composition ratio.
It is preferable that the saturation magnetic flux density Bs be smaller than that of the magnetic layer in contact with the magnetic layer. As a result, the recording magnetic field is appropriately guided from the other magnetic layer to the magnetic layer on the side in contact with the gap layers 20 and 33, so that a higher recording density can be achieved.

It is preferable that the saturation magnetic flux density Bs of the lower magnetic pole layers 19 and 32 is high, but by lowering the saturation magnetic flux density Bs of the upper magnetic pole layers 21 and 34, the gap between the lower magnetic pole layer and the upper magnetic pole layer is reduced. If the leakage magnetic field is easily inverted, the writing density of signals on the recording medium can be further increased.

FIG. 6 is a longitudinal sectional view of a thin-film magnetic head according to another embodiment of the present invention. Although the structure is very similar to the structure of the thin film magnetic head of FIG. 1, the difference is that the upper core layer 10 is formed by laminating two magnetic layers.

The upper core layer 10 comprises a high Bs layer 47 having a high saturation magnetic flux density Bs and an upper layer 4 laminated thereon.
8.

The high Bs layer 47 and / or the lower core layer 7 are formed of the FeNi-based alloy according to the present invention.

In the present invention, the FeNi-based alloy includes:
More than 0.116% by mass and less than 0.140% by mass or 0.125% by mass or more and 0.132% by mass
Contains the following element S, exceeds 55% by mass, and
Less than 80% by weight, preferably less than 68% by weight
It contains the following Fe.

According to the FeNi-based alloy, the saturation magnetic flux density Bs can be increased to 1.6 T or more, preferably 1.8 T or more, and the same Fe content is included, but the S composition ratio is lower than that of the present invention. Compared with a low soft magnetic film, the stress can be reduced and the coercive force Hc can be reduced. Coercive force Hc
Affects soft magnetic characteristics such as saturation magnetic flux density Bs and anisotropic magnetic field, and the soft magnetic characteristics can be improved as the coercive force Hc decreases. Further, the surface roughness of the film surface is small.

By using the FeNi-based alloy according to the present invention as the high Bs layer 47 and / or the lower core layer 7, soft magnetic characteristics such as saturation magnetic flux density Bs can be improved, and magnetic flux can be concentrated near the gap. As a result, the recording density can be improved, and the core layer having a predetermined shape can be easily formed with good reproducibility without causing film peeling or the like.

An upper layer 48 constituting the upper core layer 10
Although the saturation magnetic flux density Bs is smaller than that of the high Bs layer 47, the specific resistance is higher than that of the high Bs layer 47. The upper layer 48 is formed of, for example, a Ni ₈₀ Fe ₂₀ alloy.

As a result, the high Bs layer 47 has a higher saturation magnetic flux density Bs than the upper layer 48, and the magnetic flux can be concentrated near the gap to improve the recording resolution.

The upper core layer 46 has an upper layer 4 having a high specific resistance.
8, the loss due to the eddy current generated by the increase in the recording frequency can be reduced,
It is possible to manufacture a thin-film magnetic head capable of coping with a higher recording frequency in the future.

In the present invention, as shown in FIG.
It is preferable that the layer 47 is formed on the lower layer side facing the gap layer 41. Further, the high Bs layer 47 is provided at the tip end 46 a of the upper core layer 46 directly in contact with the gap layer 41.
Only it may be formed.

The lower core layer 7 may be composed of two layers, a high Bs layer and a high resistivity layer. In such a configuration,
A high Bs layer is laminated on the high resistivity layer, and the high Bs layer faces the upper core layer 10 via the gap layer 41.

In the embodiment shown in FIG. 6, the upper core layer 10 has a laminated structure of two layers, but may have three or more layers. In the case of such a configuration, the high Bs layer 47 is preferably formed on the side in contact with the magnetic gap layer 41.

FIG. 7 is a longitudinal sectional view of a thin-film magnetic head according to another embodiment of the present invention. In the embodiment of FIG. 7, the configuration of the reproducing head h1 is the same as that of FIG. As shown in FIG. 7, a lower magnetic pole layer 50 is formed on the lower core layer 7 so as to protrude from the surface facing the recording medium. The lower magnetic pole layer 50
An insulating layer 51 is formed on the rear side in the height direction (Y direction in the figure). The upper surface of the insulating layer 51 has a concave shape,
A coil forming surface 51a is formed.

From above the lower magnetic pole layer 50, the insulating layer 51
A gap layer 52 is formed upward. Further, a gap layer 5 is formed on the coil forming surface 51a of the insulating layer 51.
2, a coil layer 53 is formed. The coil layer 53 is covered with an insulating layer 54 made of organic insulation.

As shown in FIG. 7, the upper core layer 55 is patterned from the gap layer 52 to the insulating layer 54 by, for example, frame plating.

The tip 55a of the upper core layer 55 is formed on the gap layer 52 so as to face the lower pole layer 50. A base end 55b of the upper core layer 55 is magnetically connected to the lower core layer 7 via a lifting layer 56 formed on the lower core layer 7.

In this embodiment, the upper core layer 55
And / or the lower magnetic pole layer 50 is made of Fe
It is formed of a Ni-based alloy.

In the present invention, the FeNi-based alloy includes:
More than 0.116% by mass and less than 0.140% by mass or 0.125% by mass or more and 0.132% by mass
Contains the following element S, exceeds 55% by mass, and
Less than 80% by weight, preferably less than 68% by weight
It contains the following Fe.

According to the FeNi-based alloy, the saturation magnetic flux density Bs can be increased to 1.6 T or more, preferably 1.8 T or more, and the same Fe content is included, but the S composition ratio is lower than that of the present invention. Compared with a low soft magnetic film, the stress can be reduced and the coercive force Hc can be reduced. Coercive force Hc
Affects soft magnetic characteristics such as saturation magnetic flux density Bs and anisotropic magnetic field, and the soft magnetic characteristics can be improved as the coercive force Hc decreases. Further, the surface roughness of the film surface is small.

The above FeNi alloy was added to the lower magnetic pole layer 50 and / or
Alternatively, when the magnetic pole layer and the core layer are used for the upper core layer 55, the magnetic pole layer and the core layer can be formed as a film having a predetermined shape and excellent corrosion resistance without film peeling or the like. A thin-film magnetic head that can appropriately cope with the increase in recording density can be manufactured with good reproducibility.

The upper core layer 55 is entirely formed of the F
Although the upper core layer 55 may have a laminated structure of two or more magnetic layers as in FIG. 6, the side facing the gap layer 52 may be formed of a high Bs layer as the FeNi-based alloy. It may be formed of an alloy film. In such a case, only the tip 55a of the upper core layer 55 is
It is preferable that the high Bs layer is formed in contact with the gap layer 52 by forming a high-Bs layer in contact with the gap layer 52 in order to concentrate magnetic flux near the gap and improve the recording density.

In the present invention, in each of the embodiments shown in FIGS. 1 to 7, the FeNi-based alloy film is preferably formed by plating. In the present invention, the FeNi-based alloy can be formed by electroplating using a pulse current. Further, by forming the FeNi-based alloy by plating, it can be formed with an arbitrary film thickness, and can be formed with a larger film thickness than that formed by sputtering.

In each embodiment, the layer denoted by reference numeral 7 is:
The lower core layer and the upper shield layer are combined,
The lower core layer and the upper shield layer may be separately formed. In such a case, an insulating layer is interposed between the lower core layer and the upper shield layer.

Next, a general method of manufacturing the thin-film magnetic head shown in FIGS. 1 to 7 will be described below.

In the thin-film magnetic head shown in FIG. 1, first, a gap layer 8 is formed on a lower core layer 7, and a coil layer 9 is formed on the gap layer 8 by patterning. After the insulating layer 11 is formed on the coil layer 9, the upper core layer 10 is patterned from the gap layer 8 to the insulating layer 11 by frame plating.

In the thin-film magnetic head shown in FIGS. 2 and 3, the Gd determining layer 17 is formed on the lower core layer 7, and then the lower magnetic pole layer 19 and the non-magnetic The magnetic pole portion 18 including the magnetic gap layer 20 and the upper magnetic pole layer 21 is formed by continuous plating. Next, after the insulating layer 23 is formed behind the magnetic pole portion 18 in the height direction, the upper surface of the magnetic pole portion 18 and the upper surface of the insulating layer 23 are flattened using, for example, a CMP technique. After spirally patterning the coil layer 24 on the insulating layer 23, an insulating layer 25 is formed on the coil layer 24. Then, the upper core layer 22 is formed, for example, by frame plating from the magnetic pole portion 18 to the insulating layer 25.

In the thin-film magnetic head shown in FIGS. 4 and 5, after the insulating layer 31 is formed on the lower core layer 7, the resist is used to face rearward in the height direction from the surface of the insulating layer 31 facing the recording medium. Then, a track width forming groove 31a is formed. Further, the inclined surface 3 shown in FIG.
1c and 31c are formed.

A lower magnetic pole layer 32 and a nonmagnetic gap layer 33 are formed in the track width forming groove 31a. After a Gd determining layer 37 is formed on the insulating layer 31 from above the gap layer 33, an upper magnetic pole layer 34 is formed on the gap layer 33 by plating. Next, after the coil layer 38 is spirally patterned on the insulating layer 31, an insulating layer 39 is formed on the coil layer 38. Then, the upper core layer 40 is formed from the upper magnetic pole layer 34 to the insulating layer 39 by, for example, a frame plating method.

In the thin-film magnetic head shown in FIG. 6, first, a gap layer 41 is formed on the lower core
Is formed, a coil layer 44 is patterned on the insulating layer 43. After the insulating layer 45 is formed on the coil layer 44, the upper core layer 10 including the high Bs layer 47 and the upper layer 48 is patterned from the gap layer 41 to the insulating layer 45 by frame plating.

In the thin-film magnetic head shown in FIG. 7, first, a lower magnetic pole layer 50 is formed on a lower core layer 7 by using a resist,
Further, an insulating layer 5 is provided behind the lower magnetic pole layer 50 in the height direction.
Form one. After the upper surfaces of the lower magnetic pole layer 50 and the insulating layer 51 are once flattened by the CMP technique, a coil forming surface 51a having a concave shape is formed on the upper surface of the insulating layer 51. Next, the insulating layer 51 is formed on the lower magnetic pole layer 50.
After forming the gap layer 52 thereon, the gap layer 52 is formed.
A coil layer 53 is spirally patterned on the upper surface, and an insulating layer 54 is formed on the coil layer 53. Then, the upper core layer 55 is patterned from the gap layer 52 to the insulating layer 54 by, for example, frame plating.

Next, a method for producing the FeNi-based alloy of the present invention will be described. In the present invention, a film of a FeNi-based alloy containing S is formed by electrolytic plating. The electrolytic plating method has a higher film forming rate than the sputter deposition method, and can shorten the manufacturing time.

In the present invention, the plating bath used in the electrolytic plating step contains Fe ions, Ni ions, and S ions. Specifically, for example, NiCl ₂ hexahydrate, NiSO ₄ hexahydrate, FeSO ₄ hexahydrate, Na
OH, boric acid, sodium saccharin as a stress buffer, and sodium lauryl sulfate as a surfactant are put in a plating bath.
By adding saccharin sodium (C ₆ H ₄ CONNaSO ₂ ), S ions can be contained in the plating bath.

Further, according to the present invention, the plating bath
Rubonic acid is added. As the dicarboxylic acid, tartar
Acid [HOOC (C_TwoH_FourO_Two) COOH], sodium tartrate
[HOOC (C_TwoH_TwoO_TwoNa_Two) COOH], natotartaric acid
Lithium potassium [HOOC (C _TwoH_TwoO_TwoNaK) COO
H], oxalic acid (HOOCCOOH), succinic acid [HOO
C (CH_Two)_TwoCOOH], malonic acid [HOOC (CH_Two)
COOH], maleic acid (HOOCHC = CHCOO
H) can be presented.

Other examples of the dicarboxylic acid include citric acid. The molecular weight of the dicarboxylic acid is large (molecular weight is 192). If the molecular weight of the dicarboxylic acid is too large, the plating speed is inhibited, and the surface roughness of the film surface is appropriately controlled. It is thought that it cannot be suppressed.

Therefore, it is preferable to select a dicarboxylic acid having a molecular weight equivalent to or smaller than tartaric acid and to add it to the plating bath.

When the dicarboxylic acid is added to the plating bath, S ions contained in the plating bath are easily taken into the plating film, and an appropriate amount of element S is contained in the FeNi alloy. Becomes possible.

According to the present invention, by appropriately adjusting the amount of the dicarboxylic acid added, the amount of 0.116
The element S which is more than 0.1% by mass and less than 0.140% by mass can be contained.

Specifically, sodium tartrate was selected as the dicarboxylic acid. At this time, the amount of the sodium tartrate added was 37 mmol / l to the entire plating bath.
It is preferable that the amount be greater than L and less than 100 mmol / L. As a result, the content of the element S in the FeNi-based alloy is set to be larger than 0.116% by mass and 0.140% by mass.
It can be adjusted appropriately within a composition range of less than.
Further, the reason why the content of sodium tartrate is set to less than 100 mmol / L is that when sodium tartrate is added more than that, the surface roughness of the film surface becomes severe, and specifically, the center line average roughness Ra of the film surface exceeds 200 °. Would. Therefore, in the present invention, the sodium tartrate is set to less than 100 mmol / L.

In the present invention, sodium tartrate is selected as the dicarboxylic acid. At this time, the amount of the sodium tartrate added to the plating bath is 62 mm.
It is more preferable that the concentration be 1 / L or more and 82 mmol / L or less. As a result, the center line average roughness Ra of the film surface becomes 80 °.
It can be suppressed to the following.

With the addition amount of sodium tartrate, the composition ratio of the element S in the plated FeNi-based alloy is more surely larger than 0.116% by mass and smaller than 0.140% by mass. Can be According to an experiment described later, the composition ratio of the element S contained in the FeNi-based alloy can be set to 0.125% by mass or more and 0.132% by mass or less. Within this composition range,
It is possible to more effectively reduce the stress and the coercive force.

Next, in the present invention, the Fe composition ratio of the FeNi-based alloy is used. In the present invention, the Fe composition ratio is preferably more than 55% by mass and less than 75% by mass, more preferably , 68% by mass or more and 80% by mass or less.

In order to incorporate the above-mentioned amount of Fe into the FeNi-based alloy, it is preferable to use an electrolytic plating method using a pulse current instead of an electrolytic plating method using a direct current. In the electroplating method using a pulse current, for example, ON / OFF of a current control element is repeated, and a time for flowing a current and a blank time for not flowing a current are provided during plating.
By providing the time during which no current flows, the NiF
The e-based alloy film is formed by plating little by little, and it is possible to reduce the bias of the current density distribution at the time of plating, as compared with the electrolytic plating method using a direct current. According to the electroplating method using a pulse current, the content of Fe contained in the soft magnetic film can be easily adjusted as compared with the electroplating method using a direct current, and the Fe content can be incorporated into the film more.

In the present invention, in order to set the Fe content in the composition range of 68% by mass or more and 80% by mass or less, the above-described electrolytic plating method using a pulse current is used. It is preferable to reduce the concentration as compared with the conventional case. For example, in the prior art, the Ni ion concentration in the plating bath was about 40 g / l, but in the present invention, the N ion concentration is higher than this.
Set the i-ion concentration to a low concentration. As a result, during film formation,
Ni ions in the plating solution that touches the surface of the cathode (plated side) can be reduced, and the stirring effect can be enhanced.
A large amount of Fe can be contained in the Fe alloy, and the Fe content can be contained up to 80% by mass.

However, if the amount of Fe in the FeNi-based alloy is too large, the stress cannot be appropriately relieved even if dicarboxylic acid is contained in the plating bath, and the film tends to peel off due to the increase in stress. Moreover, the coercive force Hc is increased by the coarsening of the crystal grain size.
And the accompanying decrease in soft magnetic characteristics becomes a problem.

Therefore, it is important to appropriately control the upper limit of the amount of Fe in the FeNi-based alloy.
The upper limit of the amount of e is set to 80% by mass.

In the present invention, it is preferable to mix 2-butyne-1,4-diol in the plating bath of the FeNi alloy. As a result, coarsening of the crystal grain size of the plated NiFe-based alloy is suppressed, and since the crystal grain size is reduced, voids are less likely to be generated between crystals, and the surface roughness of the film surface can be more appropriately suppressed. .

In the present invention, it is preferable to mix sodium 2-ethylhexyl sulfate in the plating bath. As a result, hydrogen generated in the plating bath is removed by sodium 2-ethylhexyl sulfate, which is a surfactant, and surface roughness due to the adhesion of the hydrogen to the plating film can be suppressed.

Although sodium lauryl sulfate may be used in place of the sodium 2-ethylhexyl sulfate, it is more preferable to use sodium 2-ethylhexyl sulfate.
There is little bubbling when mixed into the plating bath, so that a large amount of the sodium 2-ethylhexyl sulfate can be mixed into the plating bath, and the hydrogen can be more appropriately removed. Further, the film stress of the NiFe alloy can be reduced by adding the sodium 2-ethylhexyl sulfate.

Hereinafter, specific plating bath compositions usable in the present invention and an example of the production process will be described.

The composition of the plating bath used in the electrolytic plating step was NiCl2 hexahydrate (117 g / L), NiS
O4 hexahydrate (50 g / L), NaOH (25 g / L
L), boric acid (25 g / L), saccharin Na (2 g / L) as a stress buffer, and sodium lauryl sulfate as a surfactant
(0.02 g / L) was added to the composition of a conventional Watt bath consisting of FeSO4 hexahydrate (35.7 g / L) and sodium tartrate (Na2C4H4O6). The addition amount is 62 to 82 mmol / L.

In the electrolytic plating step, a pulse current is applied to the plating bath using the FeNi alloy sputtered film as a cathode. Then, a FeNi-based alloy plating film is formed on the cathode to a desired thickness, and the electrolytic plating step is completed.

The deposition rate of the plating film gradually decreases as the amount of sodium tartrate added is increased. However, when the amount of sodium tartrate is added, the deposition rate is about 0.04 μm / min. At such a film formation rate, when forming a plating film of about several μm, the electrolytic plating process does not take a long time, and
It is easy to control the film thickness by the electrolytic plating process time.

In the soft magnetic film thus manufactured, the composition ratio of the element S increases with an increase in the amount of sodium tartrate added.

According to the experimental results described below, as the amount of sodium tartrate increases, both the stress of the soft magnetic film and the coercive force Hc decrease, while the composition ratio of Fe, Ni, and C becomes
In any case, the saturation magnetic flux density Bs of the soft magnetic film was not significantly reduced by the addition of sodium tartrate, without being significantly affected by the amount of sodium tartrate added.

By the way, the method of manufacturing a soft magnetic film described above is as follows.
When the lower core layer 7 and / or the upper core layer 10 shown in FIG. 1 is formed, when the lower magnetic pole layer 19 and / or the upper magnetic pole layer 21 shown in FIGS. 2 and 3 are formed, the lower magnetic pole layer 32 shown in FIGS.
And / or when forming the upper magnetic pole layer 34, when forming the lower core layer 7 and / or the high Bs layer 47 shown in FIG. 6, and when forming the lower magnetic pole layer 50 and / or upper core layer 55 shown in FIG. Is done.

By using the above-described method of manufacturing a soft magnetic film, it is possible to easily and reproducibly plate the core layer or the pole layer of the thin-film magnetic head having the structure shown in FIGS.

As shown in the embodiment shown in FIGS. 2 to 5, the magnetic pole portions 18 and 30 formed with the track width Tw between the lower core layer 7 and the upper core layers 22 and 40 are formed in a separate process. In particular, when the amount of sodium tartrate added to the plating bath is 62 mmol / L or more and 82 mmol
/ L or less.

In the thin-film magnetic head shown in FIGS. 2 and 3, a resist layer is formed on the lower core layer 7, and a groove is formed in the resist layer by exposure and development. The magnetic pole portion 18 is formed by plating in this groove. The width of the groove in the track width direction (X direction in the drawing) is set to 0.1 μm in order to appropriately cope with narrowing of the track. It is preferably about 0.5 μm, the dimension in the depth (Y direction in the figure) is also about that, and the height dimension (Z direction in the figure).
Is about 2 to 5 times the width dimension.

In order to properly form the lower magnetic pole layer 19, the gap layer 20, and the upper magnetic pole layer 21 in such an extremely narrow space, the amount of Fe is adjusted so as to increase the saturation magnetic flux density Bs of the magnetic pole layer. And the stress must be reduced, and the surface roughness of the film surface must be reduced. Otherwise, film peeling tends to occur, and a layer formed on the pole layer cannot be formed in a predetermined shape.

Therefore, in the present invention, it is preferable to appropriately adjust the plating bath composition so that the magnetic pole layer can be formed of a FeNi-based alloy having a small surface roughness and a small stress. Specifically, the amount of sodium tartrate added to the plating bath was 62 mmol / L based on the entire plating bath.
The above is set to 82 mmol / L or less.

With a FeNi-based alloy formed with this plating bath composition, a high saturation magnetic flux density Bs of 1.8 T or more can be obtained, and the center line average roughness Ra of the film surface is suppressed to 80 ° or less. And the stress is 160MP
Therefore, it is possible to easily and reproducibly form a magnetic pole layer having a high saturation magnetic flux density Bs in a very small space and free from film peeling.

In the present invention, the thin-film magnetic head shown in FIGS. 1 to 7 has been proposed as a use of the FeNi-based alloy, but the present invention is not limited to this use. For example, the F
The eNi-based alloy can also be used for a planar magnetic element such as a thin film inductor.

[0197]

Next, examples of the soft magnetic film of the present invention will be described. Table 1 shows, for Examples 1 and 2 and Comparative Examples 1 to 8, the amount of sodium tartrate added to the entire plating bath,
Composition ratio, stress, coercive force H of plated FeNi alloy
It summarizes c (hard axis / easy axis of magnetization), anisotropic magnetic field, saturation magnetic flux density Bs, specific resistance, and center line average roughness Ra of the film surface.

[0198]

[Table 1]

From this table, it can be seen that there is no significant difference in the specific resistance value between the samples.

Next, the amount of Fe will be described. Comparative Examples 1 to 5 and Examples 1 and 2 all have an Fe content of about 72% by mass and a saturation magnetic flux density Bs of about 1.9T.

On the other hand, in Comparative Example 7, the amount of Fe was very small, about 55% by mass, which is almost the same as the conventional one, and the saturation magnetic flux density Bs was at most about 1.5T. In Comparative Example 8, the amount of Fe was 68% by mass, and the saturation magnetic flux density Bs was:
It has risen to about 1.8T.

Further, in Comparative Example 6, although the Fe content was more than 80% by mass, the film could be peeled off and the experiment could not be performed.

Based on the results of this experiment, the present invention specified the amount of Fe as follows. First, the amount of Fe was set to be greater than 55% by mass and less than 75% by mass. It can be seen that within this range, the saturation magnetic flux density can be made larger than 1.5T.
If the Fe content is 72% by mass or more, the saturation magnetic flux density can be improved to about 1.9T.

In the present invention, the more preferable Fe content is 6
At least 8 mass% and no more than 80 mass%. Thereby, the saturation magnetic flux density Bs can be set to 1.8T or more. When the amount of Fe exceeds 80% by mass, it is considered that film peeling occurred due to an increase in stress. Therefore, when the amount of Fe is set to 80% by mass or less as in the present invention, it is possible to form a magnetic layer in which increase in stress is reduced and film peeling does not occur.

Next, as shown in Table 1, various characteristics such as stress, coercive force and center line average roughness Ra are not constant in each sample. In the present invention, the composition ratio of element S and each characteristic are as follows. And the relationship between the amount of sodium tartrate added and each characteristic were examined.

[0206]

[Table 2]

Table 2 shows the experimental results of the samples used to create the graphs of FIGS. Table 2 is an excerpt of the experimental results of Comparative Examples 1, 2, 3, 4, 5 and Examples 1 and 2 shown in Table 1, and Table 2 further shows that sodium tartrate Of 15 mmol /
An experimental sample designated as L is newly added. In Table 2,
8 and 9 show experimental results required, that is, the S composition ratio, stress, coercive force, and the like of each sample.

Each sample in Table 2 was obtained using the following plating bath composition. The composition of the plating bath used in the electrolytic plating step was NiCl2 hexahydrate (117 g / L), NiSO4 hexahydrate (50 g / L).
L), NaOH (25 g / L), boric acid (25 g / L
L), saccharin Na as a stress buffer (2 g / L),
The composition of a Watt bath consisting of a surfactant, sodium lauryl sulfate (0.02 g / L), was added to FeSO4 hexahydrate (35.
7g / L) and sodium tartrate (Na2C4H4O)
6), and the amount of sodium tartrate added to the entire plating bath is 0 to 100 mmol / L. Further, plating was performed by using an electrolytic plating method using a pulse current.

The following experimental results shown in FIG. 8 and later are all obtained by this experimental method.

FIG. 8 is a graph showing the relationship between the stress (MPa) and the composition ratio (% by mass) of the element S contained in the FeNi alloy. It can be seen that the stress decreases as the composition ratio of the element S increases. As shown in FIG. 8, in the section where the composition ratio of the element S is 0.116% by mass to 0.125% by mass, the stress of the FeNi-based alloy sharply decreases, and the stress can be reduced to 210 MPa or less. Understand. Further, when the composition ratio of the element S is made larger than 0.125% by mass, the stress is further reduced, though not so sharply as in the section from 0.116% by mass to 0.125% by mass. You can see that you can do it.

FIG. 9 shows the coercive force Hc (A / m) and FeNi
4 is a graph showing a relationship between composition ratios (% by mass) of elements S contained in a system alloy. As shown in FIG. 9, the coercive force Hc is
When the composition ratio of the element S is increased to 0.116% by mass or more, the degree of reduction of the coercive force Hc increases, and the coercive force Hc in the hard magnetization axis direction increases.
h to about 600 A / m or less, and the coercive force H in the easy axis direction.
It can be seen that ce can be reduced to about 470 (A / m) or less.

FIG. 10 shows the relationship between the stress (MPa) and the coercive force Hc.
It is a graph which shows the relationship of (A / m). The composition ratios of Fe in the samples in this graph are all fixed at about 72% by mass.

As shown in FIG. 10, it is understood that the coercive force Hc of Examples 1 and 2 shown in Table 1 is lower in stress and lower than that of Comparative Example.

FIG. 11 shows the relationship between the saturation magnetic flux density Bs (T) and Fe
4 is a graph showing the relationship between the S composition ratio (% by mass) contained in a Ni-based alloy. This graph shows that the amount of Fe is about 72
It was created based on an experimental sample fixed to mass%.

As shown in FIG. 11, the saturation magnetic flux density Bs
Indicates that although the composition ratio of the element S tends to slightly decrease as the composition ratio of the element S increases, the saturation magnetic flux density Bs of about 1.9 T is maintained when the element S is about 0.140 mass% or less. .

FIG. 12 shows anisotropic magnetic field (A / m) and element S
3 is a graph showing the relationship between the composition ratios (% by mass). This graph was created based on an experimental sample in which the amount of Fe was fixed at about 72% by mass.

As shown in FIG. 12, the anisotropic magnetic field increases with an increase in the composition ratio of the element S, and it can be seen that the soft magnetic characteristics improve with an increase in the composition ratio of S.

[0218]

[Table 3]

Table 3 shows the experimental results of each sample used in preparing the following FIGS. Table 2
Similarly to the above, the experimental results of Comparative Examples 1, 2, 3, 4, 5 and Examples 1 and 2 shown in Table 1 are extracted and displayed, and the amount of sodium tartrate added is 15 mmol /
An experimental sample designated as L is newly added. In Table 3,
13 to 15 show experimental results necessary for preparing FIGS. 13 to 15, that is, the S composition ratio, C composition ratio, Fe composition ratio, and the like of each sample.

FIGS. 13 to 15 show the addition amount (mmol / L) of sodium tartrate, the composition ratio of S, the composition ratio of Fe,
3 is a graph showing the relationship between the composition ratios (% by mass). FIG.
As can be seen from the graph, the S composition ratio gradually increases as sodium tartrate is added to the plating bath.

As shown in FIG. 14, the composition ratio of Fe is slightly lowered by adding sodium tartrate to the plating bath. However, in the samples used in the experiments, the ratio was about 72% by mass. It can be seen that the Fe content is maintained.

Further, as shown in FIG. 15, the composition ratio of C hardly depends on the added amount of sodium tartrate.

FIG. 16 shows the amount of sodium tartrate added,
4 is a graph showing a relationship between the stress of an FeNi-based alloy and that of the FeNi-based alloy.
As shown in FIG. 16, the addition amount of sodium tartrate was 37
When the range is from mmol / L to 62 mmol / L,
It can be seen that the stress of the FeNi-based alloy decreases rapidly. Further, although not so sharply reduced, it can be seen that the stress can be reduced even when the added amount of the sodium tartrate is 62 mmol / L or more.

FIG. 17 shows the amount of sodium tartrate added,
4 is a graph showing the relationship between the coercive force Hc (hard axis of magnetization, easy axis of magnetization) and the saturation magnetic flux density Bs of an FeNi-based alloy. As shown in FIG. 17, it is found that the coercive force Hc can be effectively reduced when the amount of sodium tartrate added is 37 mmol / L or more.

On the other hand, although the saturation magnetic flux density Bs gradually decreases with the addition of the sodium tartrate,
It can be seen that the saturation magnetic flux density Bs of about 1.9T is maintained.

FIG. 18 shows the amount of sodium tartrate added,
4 is a graph showing a relationship between an anisotropic magnetic field Hk of an FeNi-based alloy. As shown in FIG. 18, it can be seen that the addition of sodium tartrate can increase the anisotropic magnetic field and form a FeNi-based alloy having excellent soft magnetic properties.

FIG. 19 is a graph showing the relationship between the film formation rate in the electrolytic plating step and the amount of sodium tartrate added.
Although the film formation rate is slightly reduced by the addition amount of sodium tartrate, it is 0.040 μm when the addition amount of sodium tartrate is lower than 100 mmol / L.
m / min or more, and in the plating step,
It is not considered to have a significant effect.

The above experimental results show that Fe
By increasing the composition ratio of the element S contained in the Ni-based alloy, the stress and the coercive force Hc can be reduced (see FIGS. 8 and 9). On the other hand, even when the Fe composition ratio is the same but the element S is different, the saturation magnetic flux density Bs does not change much (see FIG. 11).
It was found that the addition of the element S can improve the anisotropic magnetic field and improve the soft magnetic properties.

Therefore, in the present invention, based on the above experimental results, the composition ratio of the element S contained in the FeNi-based alloy was set to 0.11.
The range is more than 6% by mass, more preferably 0.12%.
It was set to 5% by mass or more.

[0230] Also, it was found that the stress and the coercive force Hc of the FeNi-based alloy can be reduced by increasing the amount of sodium tartrate added in the plating bath. FIG.
6, 17). Further, the content of element S in the FeNi-based alloy increases with the addition of sodium tartrate, but the Fe amount does not decrease so much (FIGS. 13 and 14).
Thus, the addition of sodium tartrate does not significantly change the amount of Fe. Thus, as shown in FIG. 17, the addition of sodium tartrate significantly reduces the saturation magnetic flux density Bs. It turned out there was no. It was also found that the addition of sodium tartrate can improve the anisotropic magnetic field and improve the soft magnetic properties.

Therefore, in the present invention, based on the above experimental results, the amount of sodium tartrate added to the plating bath was 37
mmol / L, more preferably 62 mmol / L.
It was set to at least mmol / L.

Next, the upper limit of the element S contained in the FeNi-based alloy and the upper limit of sodium tartrate added to the plating bath are described below.

As shown in Table 1, in the case of Comparative Example 1,
The center line average roughness Ra of the film surface was about 83 °.
, The center line average roughness Ra is about 89 °, in the case of Example 2, the center line average roughness Ra is about 75 °, and in the case of Comparative Example 5, the center line average roughness Ra is about 75 °. The average roughness Ra was about 213 °.

The addition amount of sodium tartrate in the above four samples will be examined. Comparative Example 1 has 0 mmol / L
Comparative Example 3 is 25 mmol / L, Example 1 is 82 mmol / L, and Comparative Example 5 is 100 mmol / L.
mol / L.

The above-mentioned center line average roughness Ra of the film surface is reduced when the added amount of sodium tartrate is appropriate. However, when the added amount of sodium tartrate is too large, in this experiment, Is 8
On the other hand, when it exceeds 2 mmol / L, it is considered that the Ra increases. One reason for this may be that the film formation rate is slowed by the increase in the amount of sodium tartrate described with reference to FIG.

The center line average roughness Ra of the film surface is preferably as small as possible. When the center line average roughness Ra increases, that is, when the surface roughness increases, the corrosion resistance decreases,
Further, there arises a problem that a magnetic layer having a predetermined shape cannot be formed.

Therefore, in the present invention, the upper limit of the amount of sodium tartrate added is set to less than 100 mmol / L. This shows that the center line average roughness Ra of the film surface can be suppressed to about 200 ° or less. More preferably, the addition amount of the sodium tartrate is 82 mmol / L or less. This makes the center line average roughness Ra about 80 °.
It can be seen that it can be suppressed below.

Therefore, in the present invention, the addition amount of sodium tartrate is more than 37 mmol / L and 100 mm
ol / L. A more preferable range is 6
It was set to 2 mmol / L or more and 82 mmol / L or less.

The amount of the sodium tartrate added was 1
FIG. 13 shows that when the content is less than 00 mmol / L, preferably 82 mmol / L or less, the content of the element S in the FeNi-based alloy is less than 0 and 140% by mass. The amount of the sodium tartrate added was 82 mmol.
/ L or less, it can be seen that the content of element S can be reduced to 0.132% by mass or less.

According to the results of this experiment, the present invention
The composition ratio of the element S in the Ni-based alloy is specified to be more than 0.116% by mass and less than 0.140% by mass;
Preferably, it is specified as 0.125% by mass or more and 0.132% by mass or less.

Next, the experimental results of the corrosion resistance will be described below. In the experiment, a magnetic pole portion having a shape as shown in FIG. 20 was formed. Lowest layer is a Fe ₂₀ Ni ₈₀ alloy film, Hi-B having a high saturation magnetic flux density Bs thereon (bottom pole layer)
Film, NiP (gap layer) film, Hi-B (upper pole layer)
The film was formed by plating.

[0242]

[Table 4]

In the present invention, two Hi-B films were formed by plating with the two magnetic layers listed in Table 4. One is an FeNi-based alloy formed with 0 mmol / L of sodium tartrate in the plating bath, and the other is FeN-based alloy formed with 82 mmol / L of sodium tartrate in the plating bath.
It is an i-based alloy. In addition, ten samples were prepared.

In the experiment, the sample composed of the laminated film shown in FIG. 20 was immersed in pure water having a pH of 4.7 for 10 minutes.
A sample composed of the laminated film in FIG. 20 was immersed in dilute sulfuric acid at 2.0 for 1 minute. And the degree of corrosion was measured.

As shown in Table 4, sodium tartrate was 0
The FeNi-based alloy formed as mmol / L is Hi-
In the sample of the laminated film used as the B film and the sample of the laminated film using the FeNi-based alloy formed with 82 mmol / L of sodium tartrate as the Hi-B film, both samples were immersed in pure water. No corrosion was seen.
On the other hand, when immersed in dilute sulfuric acid, both samples
Less than half of the samples were corroded,
Four samples formed with sodium tartrate at 0 mmol / L were corroded, whereas three samples with sodium tartrate added at 82 mmol / L or less had 3 corroded.
It was corrosion of the pieces.

Thus, the amount of sodium tartrate added was 8
If it is 2 mmol / L or less, FeNi having excellent corrosion resistance
It was found that the base alloy could be formed by plating. This is because, for a FeNi-based alloy formed with the addition amount of sodium tartrate of 82 mmol / L or less, the center line average roughness R
This is considered to be because a could be reduced. Specifically, the center line average roughness Ra can be set to 80 ° or less (see Table 1 and the like).

Finally, the relationship between the sample used in the experiment and the crystal grain size and crystal orientation was examined. Table 5 shows the experimental results.

[0248]

[Table 5]

From the experimental results of the (111) reflection line width in Table 5, the size of the crystal grain size can be predicted.
11) The reflection line width does not change depending on the amount of sodium tartrate added, and it is considered that the crystal grain size of the FeNi alloy hardly changes. As described above, when the crystal grain size is small, a decrease in stress is generally observed. However, according to the experimental results, the decrease in stress due to the inclusion of the element S has almost no relation to the size of the crystal grain size. It is considered something. In addition, the crystal orientation was hardly changed in each sample.

[0250]

As described above, the soft magnetic film of the present invention is characterized in that Fe containing S
It is a Ni-based alloy, and the composition ratio of S exceeds 0.116% by mass and is less than 0.140% by mass.

In such a soft magnetic film, the composition ratio of S is
When the content is more than 0.116% by mass and less than 0.140% by mass, the stress and the coercive force Hc are increased as the composition ratio of S increases.
Therefore, both low stress and excellent soft magnetic characteristics can be achieved. Further, the surface roughness of the film surface can be reduced.

In the present invention, the composition ratio of Fe is more than 55% by mass and less than 75% by mass, or preferably 68% by mass or more and 80% by mass or less. Thereby, the saturation magnetic flux density becomes 1.6T or more, preferably 1.8T.
According to the present invention, the stress can be reduced, the coercive force can be reduced, and the surface roughness of the film surface can be reduced while maintaining the high saturation magnetic flux density.

The method for producing a soft magnetic film of the present invention
Is a method of forming a film of a FeNi-based alloy containing Ni by electrolytic plating, wherein a composition of a plating bath used in the electrolytic plating step contains a solution containing Fe ions, Ni ions, and S ions, and further contains a dicarboxylic acid. It was done.

Preferably, the dicarboxylic acid is specifically sodium tartrate. In the present invention, the amount of sodium tartrate added to the entire plating bath is 37 m.
It is preferable that the amount exceeds mol / L and is less than 100 mmol / L. More preferably, it is 62 mmol / L or more and 82 mmol / L or less.

In such a method for producing a soft magnetic film, since sodium tartrate is added to the plating bath, S is precipitated in the plating film, and a FeNi alloy plating film containing S can be produced. In addition, when the amount of sodium tartrate is added, the stress and coercive force of the plated FeNi-based alloy can be effectively reduced, and the center line average roughness Ra of the film surface can be effectively reduced.

The thin-film magnetic head of the present invention also has a lower core layer, a gap layer formed on the lower core layer and made of an insulating material, and a coil layer formed on the gap layer and made of a good conductive material. And an insulating layer covering the coil layer, and an upper core layer formed on the insulating film, wherein a recording magnetic field is applied to the upper core layer and the lower core layer by a current applied to the coil layer. In this case, at least one of the upper core layer and the lower core layer uses the soft magnetic film.

In such a thin film magnetic head, the soft magnetic film serving as the upper core layer and / or the lower core layer has lower stress and lower retention than the conventional soft magnetic film having the same Fe composition ratio. Since the magnetic force is Hc, the adhesion between the lower core layer and the insulating layer or / and the upper core layer and the gap layer, and the reliability of recorded data are improved, and a thin film magnetic head capable of coping with high recording density is manufactured. It becomes possible to do.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a thin-film magnetic head,

FIG. 2 is a partial front view of a thin-film magnetic head according to another embodiment of the present invention;

FIG. 3 is a longitudinal sectional view of FIG. 2;

FIG. 4 is a partial front view of a thin-film magnetic head according to another embodiment of the present invention;

FIG. 5 is a longitudinal sectional view of FIG. 4;

FIG. 6 is a longitudinal sectional view of a thin-film magnetic head according to another embodiment of the present invention;

FIG. 7 is a longitudinal sectional view of a thin-film magnetic head according to another embodiment of the present invention;

FIG. 8 is a graph showing the relationship between the stress and the S composition ratio of the soft magnetic film of the present invention.

FIG. 9 is a graph showing the relationship between the coercive force Hc and the S composition ratio of the soft magnetic film of the present invention.

FIG. 10 is a graph showing the relationship between the stress of the soft magnetic film of the present invention and the coercive force Hc.

FIG. 11 is a graph showing the relationship between the saturation magnetic flux density Bs and the S composition ratio of the soft magnetic film of the present invention.

FIG. 12 is a graph showing the relationship between the anisotropic magnetic field and the S composition ratio of the soft magnetic film of the present invention.

FIG. 13 is a graph showing the relationship between the S composition ratio of the soft magnetic film of the present invention and the amount of sodium tartrate added to the plating bath.

FIG. 14 is a graph showing the relationship between the Fe composition ratio of the soft magnetic film of the present invention and the amount of sodium tartrate added to the plating bath.

FIG. 15 is a graph showing the relationship between the C composition ratio of the soft magnetic film of the present invention and the amount of sodium tartrate added to the plating bath.

FIG. 16 is a graph showing the relationship between the stress of the soft magnetic film of the present invention and the amount of sodium tartrate added to the plating bath.

FIG. 17 is a graph showing the relationship between the coercive force Hc of the soft magnetic film of the present invention and the amount of sodium tartrate added to the plating bath.

FIG. 18 is a graph showing the relationship between the anisotropic magnetic field Hk of the soft magnetic film of the present invention and the amount of sodium tartrate added to the plating bath.

FIG. 19 is a graph showing the relationship between the film formation rate in the soft magnetic film plating step of the present invention and the amount of sodium tartrate added to the plating bath.

FIG. 20 is a sectional view showing the structure of a laminated film used in the experiment in Table 4.

FIG. 21 is a graph showing the relationship between stress and coercive force Hc of a conventional soft magnetic film made of an FeNi alloy.

[Explanation of symbols]

 h2 Recording head section G Write gap 7 Lower core layer 8 Gap layer 9 Coil layer 10 Upper core layer 11 Insulating layer 18, 30 Magnetic pole section 19, 32, 50 Lower magnetic pole layer 21, 34 Upper magnetic pole layer 47 High Bs layer 48 Upper layer

Claims (24)

[Claims] 1. An FeNi-based alloy containing S, wherein S
A soft magnetic film characterized by having a composition ratio of more than 0.116% by mass and less than 0.140% by mass. 2. The soft magnetic film according to claim 1, wherein the composition ratio of S is 0.126% by mass or more. 3. The soft magnetic film according to claim 1, wherein the composition ratio of S is 0.125% by mass or more and 0.132% by mass or less. 4. The soft magnetic film according to claim 1, wherein the composition ratio of Fe is more than 55% by mass and less than 75% by mass. 5. The soft magnetic film according to claim 4, wherein the composition ratio of Fe is 72% by mass or more. 6. The soft magnetic film according to claim 1, wherein the composition ratio of Fe is 68% by mass or more and 80% by mass or less. 7. A thin-film magnetic head comprising: a lower core layer made of a magnetic material; an upper core layer formed on the lower core layer via a magnetic gap; and a coil layer for applying a recording magnetic field to both core layers. A thin-film magnetic head, wherein at least one core layer is formed of the soft magnetic film according to any one of claims 1 to 6. 8. The thin-film magnetic head according to claim 7, wherein a lower magnetic pole layer is formed on the lower core layer at a surface facing the recording medium, and the lower magnetic pole layer is formed of the soft magnetic film. 9. A lower core layer and an upper core layer, and a width dimension between the lower core layer and the upper core layer in a track width direction is regulated to be shorter than the lower core layer and the upper core layer. A magnetic pole portion, wherein the magnetic pole portion includes a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer. And
Alternatively, the magnetic pole portion includes an upper magnetic pole layer continuous with an upper core layer, and a gap layer located between the upper magnetic pole layer and the lower core layer. The upper magnetic pole layer and / or the lower magnetic pole layer includes: 7. A thin-film magnetic head formed of the soft magnetic film according to claim 1. 10. The upper magnetic pole layer is formed of the soft magnetic film, and the upper core layer formed on the upper magnetic pole layer is formed of a soft magnetic film having a lower saturation magnetic flux density Bs than the upper magnetic pole layer. 10. The thin-film magnetic head according to claim 9, wherein: 11. The core layer, wherein at least a portion adjacent to the magnetic gap is made of two or more magnetic layers, or the pole layer is made of two or more magnetic layers, and The thin-film magnetic head according to any one of claims 7 to 10, wherein the magnetic layer in contact is formed by the soft magnetic film. 12. The thin-film magnetic layer according to claim 11, wherein the other magnetic layer other than being in contact with the magnetic gap layer is formed of a soft magnetic film having a lower saturation magnetic flux density Bs than the magnetic layer in contact with the magnetic gap layer. head. 13. A method for forming a film of an FeNi-based alloy containing S by electrolytic plating, wherein a plating bath used in the electrolytic plating step contains Fe ions, Ni ions and S ions, and the plating bath A method for producing a soft magnetic film, characterized by adding a dicarboxylic acid therein to form a soft magnetic film having a composition ratio of S exceeding 0.116% by mass and less than 0.140% by mass. 14. The dicarboxylic acid is sodium tartrate, and the amount of the sodium tartrate added is more than 37 mmol / L to the entire plating bath, and
The method for producing a soft magnetic film according to claim 13, wherein the concentration is less than 0 mmol / L. 15. The dicarboxylic acid is sodium tartrate, and the amount of the sodium tartrate added is 82 mmol / L or more to 62 mmol / L or more based on the entire plating bath.
The method for producing a soft magnetic film according to claim 13, wherein the ratio is not more than / L. 16. The composition ratio of S is 0.125% by mass.
The method for producing a soft magnetic film according to claim 15, wherein a soft magnetic film having a concentration of 0.132% by mass or less is formed by plating. 17. The method for producing a soft magnetic film according to claim 13, wherein saccharin sodium is mixed in the plating bath. 18. The method for manufacturing a soft magnetic film according to claim 13, wherein the soft magnetic film is formed by plating using an electrolytic plating method using a pulse current. 19. A lower core layer made of a magnetic material, an upper core layer facing the lower core layer via a magnetic gap on a surface facing the recording medium, and a coil layer for inducing a recording magnetic field in both core layers. The method of manufacturing a thin-film magnetic head comprising: the upper core layer and / or the lower core layer.
20. A method of manufacturing a thin-film magnetic head, comprising plating with a soft magnetic film formed by the manufacturing method according to any one of the above items. 20. The thin-film magnetic head according to claim 19, wherein a lower magnetic pole layer is formed on the lower core layer at a surface facing the recording medium, and the lower magnetic pole layer is formed by plating with the soft magnetic film. Manufacturing method. 21. A lower core layer and an upper core layer, and a width dimension between the lower core layer and the upper core layer in a track width direction is regulated to be shorter than the lower core layer and the upper core layer. A magnetic pole portion, wherein the magnetic pole portion is formed of a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer. Alternatively, the magnetic pole part is formed of an upper magnetic pole layer continuous with an upper core layer, and a gap layer located between the upper magnetic pole layer and the lower magnetic core layer, and the upper magnetic pole layer and / or the lower magnetic pole layer Claim 13
20. A method of manufacturing a thin-film magnetic head, comprising plating with a soft magnetic film formed by the manufacturing method according to any one of the above items. 22. The upper magnetic pole layer is formed by plating with the soft magnetic film, and the upper core layer formed on the upper magnetic pole layer is formed of a soft magnetic film having a lower saturation magnetic flux density Bs than the upper magnetic pole layer. 22. The method of manufacturing a thin-film magnetic head according to claim 21. 23. At least a portion of the core layer adjacent to the magnetic gap is formed of two or more magnetic layers, or the pole layer is formed of two or more magnetic layers. 23. The method of manufacturing a thin-film magnetic head according to claim 19, wherein a magnetic layer in contact with the magnetic layer is formed by plating with the soft magnetic film. 24. The thin-film magnetic head according to claim 23, wherein the other magnetic layer other than contacting the magnetic gap layer is formed of a soft magnetic film having a lower saturation magnetic flux density Bs than the magnetic layer contacting the magnetic gap layer. Manufacturing method.