JPH03250413A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To arrange magnetic domains having uniaxial anisotropy in a track width direction in the track part of a magnetic core formed on a band-shaped hydrophobic region nearly parallel with this direction by forming the above- mentioned region on the front surface of a plating underlying film. CONSTITUTION:This magnetic head is formed with the magnetic core 3 via the plating underlying film 2. The core 3 is formed thinly in the band-shaped hydrophobic region 1a formed on the surface of the film 2 as the plating hardly sticks thereto. The core is thickly formed in the region 11b which is not hydrophobic. This region 11a is formed by applying a resist on, for example, the film 2 and forming a resist layer 11 nearly parallel with the track width direction in the position corresponding to the point where the core 3 is formed, then removing the layer 11 and forming this region in the region where there was the layer 11. The projecting parts 13a of a 'Permalloy(R)' film 13 to be formed on the film 2 parallels nearly with the track width direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head suitable for writing or continuously outputting information to a magnetic recording medium such as a magnetic tape, a magnetic disk, or a hard disk.

[Summary of the invention]

The present invention provides a thin-film magnetic head in which a magnetic circuit portion is formed by thin-film forming technology, in which a band-shaped hydrophobic region approximately parallel to the track width direction is formed on the surface of the plating base film, and a magnetic film made of a magnetic film is formed on the surface of the plating base film. By forming the core, magnetic domains having uniaxial anisotropy in the track width direction can be easily arranged in the track portion of the magnetic core, thereby stabilizing the magnetic domains.

[Conventional technology]

In general, in thin-film magnetic heads, the magnetic film and conductor coil that make up the magnetic circuit are formed using a 1-meter vacuum forming technique, which makes it easy to achieve finer dimensions such as narrower tracks and narrower gaps, and also enables quantitative resolution recording. It has the characteristic of being able to perform high-density recording, and is attracting attention as a magnetic head compatible with high-density recording.

This type of thin-film magnetic head usually has a single-layer or multiple-layer conductor coil laminated on a lower magnetic body with an insulating film interposed therebetween, and an upper magnetic body on top of this conductor coil with an insulating film interposed therebetween. The magnetic circuit section is formed by forming the magnetic circuit section.

By the way, in the *film magnetic head mentioned above, with the remarkable improvement in recording density in recent years, electromagnetic conversion characteristics, especially recording and
The playback output is further improved. Therefore, in the thin film magnetic head described above, the stability of the magnetic domain of the magnetic film, which greatly affects the tm conversion characteristics, is becoming increasingly important. In order to make the magnetic domain stable, it is necessary that the magnetic film has a magnetic domain having magnetic anisotropy in the track width direction in the track portion where it makes sliding contact with the magnetic recording medium. This applies to high frequency regions (e.g. 1
This is for reasons such as improving the reproduction output in the frequency range (~5MHz) and preventing wiggle (a type of noise caused by domain wall movement) in the reproduction output waveform.

In order to impart magnetic domains having magnetic anisotropy in the track width direction to the track portion of the magnetic film, for example, by making grooves in the track width direction on the substrate, the magnetic film formed thereon is made to have an uneven shape. A method in which the axes of easy magnetization are arranged in the track width direction, and a method in which a magnetic field is externally applied in the track width direction when forming a magnetic film by so-called frame plating are known.

However, with the method of adding magnetic domains by making grooves in the substrate,
Grooving by mechanical means takes a lot of time (and it is not possible to form fine groove patterns due to restrictions such as the width of the grinding wheel.In addition, in the method of applying an external magnetic field, the influence of the demagnetizing field Therefore, it is difficult to orient the magnetic domains in the width direction of the track, and this leaves some dissatisfaction in terms of playback output, noise, etc.

[Problem to be solved by the invention]

As described above, with the conventional methods, it is not only difficult to easily provide magnetic domains having magnetic anisotropy in the track width direction, but also the magnetic domains cannot be precisely controlled. Furthermore, a significant improvement in reproduction output cannot be expected due to the influence of demagnetizing fields and the like.

The present invention has been developed in view of the above-mentioned conventional circumstances, and makes it possible to easily impart magnetic domains having magnetic anisotropy in the track width direction to the track portion of a magnetic core, and to control the magnetic domains. Thin 11 [
Another object of the present invention is to provide a thin film magnetic head with high head efficiency and which can significantly improve output.

[Means to solve the problem]

To achieve the above object, the thin film magnetic head of the present invention includes a plating base film formed on a substrate, a band-shaped hydrophobic region substantially parallel to the track width direction on the surface of the plating base film, and a hydrophobic region substantially parallel to the track width direction. This is characterized in that a magnetic core made of a magnetic film is formed thereon.

[Effect]

In the present invention, since a band-shaped hydrophobic region approximately parallel to the track width direction is formed on the surface of the plating base film, plating generally has a property that it is difficult to adhere to hydrophobic areas, The magnetic film formed has an uneven shape corresponding to the pattern of the hydrophobic region. Therefore, the magnetic anisotropy of the magnetic film is arranged in the direction along the hydrophobic region in the track width direction, that is, in the track width direction.

〔Example〕

Hereinafter, specific embodiments of a thin film magnetic head to which the present invention is applied will be described.

In this embodiment, a frame (outer frame) corresponding to a desired core shape is formed using an insulating material, plating is performed, and the plating outside the frame is removed to form a magnetic core. An example of a thin film magnetic head in which a magnetic film is formed by a so-called frame plating method will be described.

As shown in FIG. 1, the thin film magnetic head of this embodiment has a first magnetic core (3) made of a magnetic film formed on a substrate (1) with a plating base film (2) interposed therebetween. Insulated pancreas (
4) through which a second conductor coil (5) and a magnetic film are connected.
A magnetic core (6) is formed.

As the substrate (1), a substrate made of a nonmagnetic material such as potassium titanate ceramics or alumina, or a substrate made of a ferromagnetic material such as Mn-Zn ferrite or NiZn ferrite is used.

The first magnetic core (3) formed on the substrate (1) is integrally formed by frame plating in a direction substantially orthogonal to the track width direction, that is, in the depth direction of the magnetic gear g, The surface opposite to the surface formed on the substrate (1) is uneven. this is,
A band-shaped hydrophobic region on the surface of the plating base film (2) that is approximately parallel to the track width direction [a region corresponding to the concave part of the magnetic core (3) surface, that is, the thin core thickness part'] corresponds to the track width. This is because a plurality of them are formed at predetermined intervals in a direction substantially orthogonal to the direction. In other words, since plating generally shows a property that it is relatively difficult to attach to hydrophobic parts,
There is a difference in plating thickness between hydrophobic and non-hydrophobic areas,
This results in an uneven shape. The magnetic core (3) thus formed is shaped into a strip in a direction substantially perpendicular to the track width direction in accordance with the pattern of the hydrophobic region formed on the surface of the plating base 111(2), and The portion corresponding to the hydrophobic region is approximately parallel to the track width direction, and the magnetic anisotropy of this portion is oriented in the track width direction. Therefore, in the track portion of the first magnetic core (3), magnetic domains exhibiting uniaxial anisotropy are arranged in the track width direction, and the magnetic domains are stabilized.

A ferromagnetic material having a high saturation magnetic flux density and excellent soft magnetic properties can be used for the first magnetic core (3). For example, Ni-Fe alloy, Fe-Al alloy, Fe-Af
-3i alloy, Fe-3iCo alloy, Fe-Al-G
e-based alloy, FeGa-Ge-based alloy, Fe-3i-Ge
ferromagnetic metal materials such as Fe-Co-31-Al alloys, FeGa-3i alloys, and the above F
In order to further improve the corrosion resistance and wear resistance of the e-Ga-3i alloy, Fe, Ga, and C are added.

(Including those in which a part of Fe is replaced with Co.) In the alloy whose basic composition is Si, Ti, Cr, MnZr, Nb, M
o, Ta, W Ru Os RhIr, Re, N
At least one of i, Pb, PL, Hf, and V may be added. However, a material whose magnetic domain can be easily controlled, such as a Fe-Ni alloy (permalloy), is usually used.

Further, on the first magnetic core (3), a magnetic gear,
A gap film (7) is formed to constitute the gap g. The gap film (7) is made of, for example, 5iOz or Ta.
A membrane made of 2O3 or the like is used.

Further, on the gap film (7), a conductor coil (5) made of a conductive metal material such as Cu or AI is embedded in the insulating film (4) in a plurality of turns (4 turns in this example) at predetermined intervals. It is formed in a spiral shape. The form of the conductor coil (5) is not particularly limited, and may be, for example, a helical type, a zigzag type, or the like. Further, the conductor coil (5) may not only have a -layer winding structure as in this example, but may also have a multilayer winding vA structure.

Further, on the insulating film (4), a second magnetic core (6) that cooperates with the first magnetic core (3) to constitute a magnetic circuit section is also provided on the first magnetic core. Similar to (3), it is formed of a ferromagnetic material into a desired shape. That is, the second magnetic core (6) is a conductor coil (5).
The spiral is formed from the center of the spiral to the vicinity of the surface facing the magnetic recording medium, and in the center of the spiral, the first The magnetic core (3) is connected to the magnetic core (3) to form a hack gap.

On the other hand, near the surface facing the magnetic recording medium, the second magnetic core (6) sandwiches the gap film (7) and connects the first magnetic core (
3) to form a magnetic gap g. Therefore, the first magnetic core (3) and the second magnetic core (6) are magnetically coupled via the back gap and the magnetic gap with the conductor coil (5) sandwiched in the center, and the magnetic circuit section is Configure.

Further, on the second magnetic core (6), a protective plate (9) for protecting the magnetic circuit section and ensuring contact with the magnetic recording medium is attached using an adhesive (10) such as a low melting point glass.
They are fusion-bonded via.

In the thin lIW magnetic head configured in this way,
The magnetic domain is stable because the axis of easy magnetization of the first magnetic core (3) is oriented in the same direction as the hydrophobic region formed on the surface of the plating base film (2) and approximately parallel to the track width direction. Therefore, there is no wiggle order in the reproduced waveform, and the reproduction output in the high frequency region is improved.

By the way, the above thin film magnetic head was manufactured in the following manner.

First, as shown in FIG. 2(a), a substrate (1) made of ceramics, ferrite, etc. is prepared, and permalloy 1Il (N
i-Fe film) was formed over the entire surface. In this example,
The plating base film (2) made of the above permalloy was coated with 1000
As a person.

Next, as shown in FIG. 2(b), the plating base 1
1! (2) Apply a resist on top, and place a strip-shaped resist layer (11) approximately parallel to the track width direction (arrow T direction in the figure) at a position corresponding to the location where the magnetic core will be formed, and approximately perpendicular to the track width direction. The strips were formed at predetermined intervals in the direction shown in FIG.

Incidentally, since the interval between the resist layers (11) is arbitrarily determined by exposure and development, the interval can be made much narrower than when grooves are formed by conventional machining. Therefore, the magnetic domains of the first magnetic core (3) formed thereon can be finely controlled.

Next, the resist layer (11) was removed by resist stripping M'lfg using acetone or the like.

When the surface of the base film (2) from which the resist layer (11) was removed was observed, as shown in Figure 2(c), the area (lla) where the resist layer (11) had been attached (in the figure - indicated by the dotted chain line) It was observed that the region shown] was more hydrophobic than the region (Ilb) to which the resist layer (11) was not attached.

Next, as shown in FIG. 2(d), a frame (I2) made of resist was formed on the plating base film (2) according to a predetermined core shape by photolithography.

In this step, the resist is once applied over the entire surface of the substrate (1), but the hydrophobic region on the surface of the plating base film (2) formed in the above-mentioned step remains. Although the cause of this is not clear, an actual investigation revealed that the hydrophobic region formed in the previous step remained.

Next, as shown in FIG. 2(e), a permalloy film (13) was plated on the entire surface of the substrate (1) except for the frame (12).

Note that the plating conditions here are not particularly limited, and the conditions conventionally used in this type of field can be used.

As a result, the area (llb) to which the resist layer (11) was not attached is likely to be plated, and the resist layer (11) is likely to be plated.
) It was relatively difficult for plating to adhere to the hydrophobic region (lla). When the plating thickness reaches about 3 μm, as shown in Figure 2(f), the hydrophilic area (llb) and the hydrophobic area (lla) are 0.05~0. , a step difference of about 1 μm occurred.

Due to this level difference, the permalloy film (13) has an uneven cross-sectional shape, and the convex portions (13a) are substantially parallel to the track width direction and arranged in a strip shape in a direction substantially perpendicular to the track width direction. It took shape.

Permalloy 1111 (13
) was oriented in the track width direction. Note that the magnetic anisotropy of the other portions other than the track portion was also oriented in the track width direction.

Next, as shown in FIG. 2(g), a resist layer (14) is formed to cover the permalloy film (13) surrounded by the frame (I2), and then wet etching is performed to Permalloy membrane (13) outside the frame (12)
was removed to form a first magnetic core (3) made of a permalloy film as shown in FIG. 2(h).

By going through the above steps, a head core with stabilized magnetic domains in which the direction of magnetic anisotropy is aligned in the track width direction is formed.

Thereafter, a conductor coil, an insulating film, a second magnetic core, etc. were sequentially formed by a conventional method to complete a thin film magnetic node.

It was found that the thin film magnetic head produced through the above steps had excellent reproduction output in the high frequency range, and no wiggle occurred in the reproduced waveform.

〔Effect of the invention〕

As is clear from the above explanation, in the thin film magnetic heel of the present invention, the magnetic core is formed on a plating base film in which a band-shaped hydrophobic region is formed approximately parallel to the track width direction. , magnetic domains having uniaxial anisotropy are arranged in the track width direction in the track portion of the magnetic core, and the magnetic domains become stable. Therefore, the reciprocating output in the high frequency region is improved, wiggles do not occur in the reproduced waveform, and the head efficiency is improved.

Moreover, the thin Il of the present invention! In a magnetic head, magnetic domains having uniaxial anisotropy can be easily arranged in the track width direction simply by forming a hydrophobic region on the surface of a plating base film.

Further, according to the thin film magnetic head of the present invention, by finely controlling the hydrophobic region, it is possible to more finely control the magnetic domain of the magnetic core.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of essential parts showing an example of an IN magnetic head to which the present invention is applied. 2(a) to 21ffi(h) sequentially show the steps of forming a magnetic core by frame plating, and FIG. 2(a) is an enlarged perspective view showing the step of forming a plating base film; 2(b) is an enlarged perspective view showing the resist layer forming process, FIG. 2(c) is an enlarged perspective view showing the resist layer removing process, 21m(d) is an enlarged perspective view showing the frame forming process, Figure (e) is an enlarged perspective view showing the Mesoki process, Figure 2 (f) is a sectional view taken along the aa line of Figure 2 (e), Figure 2 (g
) is an enlarged perspective view showing the step of forming a resist layer, and FIG. 2(h) is an enlarged perspective view showing the etching step. 1... Substrate 2... Plating base film 3... First magnetic core 11a... Hydrophobic region

Claims (1)

[Claims] A thin film magnetic film is formed in which a plating base film is formed on a substrate, a band-shaped hydrophobic region approximately parallel to the track width direction is formed on the surface of the plating base film, and a magnetic core made of a magnetic film is formed on the surface of the plating base film. head.