JPH01311406A - Magnetic head for perpendicular recording - Google Patents

Abstract

PURPOSE:To reduce a sliding noise by setting the area of a soft magnetic film sufficiently small in size, and also, setting the end face of a soft magnetic film confronting with a magnetic recording medium in non-parallel for that of a main magnetic pole. CONSTITUTION:A magnetic core 21 sandwiches the main magnetic pole 22 having high saturated magnetic flux density with main magnetic pole auxiliary magnetic materials 23a and 23b consisting of a bulk material such as Mn-Zn ferrite and main magnetic pole auxiliary cores 30a and 30b being constituted of main magnetic pole auxiliary non-magnetic materials 24a and 24b consisting of flint glass from both sides. In auxiliary cores 20a and 20b, winding grooves are formed on non-magnetic protection substrates 26a and 26b, and auxiliary magnetic poles 25a and 25b are formed at the end face including the inner wall of the groove between the confronting plane of the magnetic medium of the substrates 26a and 26b and a rear end part, and non- magnetic materials 28a and 28b such as the flint glass, etc., are filled in the end part confronting with the main magnetic core 21 a the confronting plane side of the magnetic recording medium. In the non-magnetic protection substrates 26a and 26b, a material such as zirconia or saphire, etc., with a superior anti-sliding property against the magnetic recording medium is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head for perpendicular recording that is suitable and practical for use in a perpendicular magnetic recording system.

[Conventional technology]

A perpendicular magnetic recording method in which a magnetic recording medium is magnetized in the thickness direction is attracting attention as a magnetic recording method suitable for high-density magnetic recording. To successfully perform perpendicular magnetic recording, a magnetic recording medium consisting of a ferromagnetic film with strong axial anisotropy perpendicular to the film surface and a magnetic head that generates a steep and strong perpendicular component magnetic field to the recording medium are required. Is required.

Conventionally, as this type of magnetic head, a one-sided perpendicular magnetic recording head in which a main pole and an auxiliary pole are arranged on the same surface has been proposed. (Unexamined Japanese Patent Publication No. 56-3422,
JP-A-60-66308, JP-A-58-1532
(No. 16 Publication) These magnetic heads consist of a main pole made of a metal magnetic thin film with high saturation magnetic flux density and a high magnetic permeability magnetic bulk material.
It has an integrated structure with an auxiliary magnetic pole consisting of.

The above conventional technology has a configuration as shown in FIGS. 13 and 14. The magnetic recording medium 11 includes a non-magnetic substrate 17
A perpendicular magnetization film 15 made of Co--Cr or the like having an easy axis of magnetization perpendicular to the film surface is formed thereon via a high magnetic permeability film 16 of permalloy or the like having an easy axis of magnetization in the film surface. It is.

The magnetic head 10 consists of a main magnetic pole 12 with a rectangular cross section and auxiliary magnetic poles 13a and 13b, and the main magnetic pole 12 is magnetized by a signal current flowing through an excitation coil 14 wound around the main magnetic pole 12.
The perpendicular magnetic film 15 is caused by the perpendicular magnetic field generated at its tip.
It is now possible to record to. . Therefore, in order to obtain a vertical component magnetic field with a steep distribution, the thickness of the tip of the main pole 12 is made thin. Since the magnetic flux density is high in this part, a magnetic thin film with high saturation magnetic flux density and high magnetic permeability, such as sendust, permalloy, or an amorphous alloy, is used.

On the other hand, in the auxiliary magnetic poles 13a and 13b, the magnetic flux (indicated by the dotted arrow) generated from the end face of the main magnetic pole 12 is transferred to the perpendicularly magnetized film 1.
5, serves as a magnetic flux converging magnetic pole that efficiently converges the magnetic flux that is attenuated and diffused inside the high magnetic permeability film 16 and in the air, and returns it to the main magnetic pole 12 again. Therefore, the auxiliary magnetic pole 13
A high magnetic permeability bulk material such as Mn-Zn ferrite is used for a and 13b.

The magnetic head having the structure shown in FIG. 13 has the following advantages and disadvantages. The first is auxiliary magnetic poles 13a, 13b
Since the magnetic recording medium 11 slides in contact with the magnetic recording medium 11, the magnetic flux convergence efficiency is good, and the recording and reproduction efficiency is good. The second is to connect the ends 18a, 18b of the auxiliary magnetic poles 13a, 13b to the main magnetic pole 12.
By making the ends non-parallel to the auxiliary magnetic poles 13a and 13b,
8a.

No unusual electromagnetic conversion characteristics other than necessary are exhibited due to recording and reproduction in the 18b. The third is an auxiliary magnetic pole 13a made of a magnetic bulk material such as Mn-Zn.

Since the magnetic recording medium 13b slides in contact with the magnetic recording medium 11, it has advantages and disadvantages such as being susceptible to noise generated by sliding and spike noise from the high magnetic permeability film 16.

On the other hand, in the magnetic head having the structure shown in FIG. 14, firstly, non-magnetic materials 19a and 19b are installed on the side of the auxiliary magnetic poles 13a and 13b facing the magnetic recording medium, and the auxiliary magnetic poles are separated from the magnetic recording medium 11. By doing so, the auxiliary magnetic pole 13a is less affected by sliding noise caused by sliding with the magnetic recording medium 11 and spike noise from the high magnetic permeability film 16.
, 13b are spaced apart from the magnetic recording medium 11, the ends 18a of the auxiliary magnetic poles 13a, 13b
, 18b, the auxiliary magnetic poles 13a, 1 rarely exhibit unusual electromagnetic conversion characteristics other than necessary due to recording and reproduction in the auxiliary magnetic poles 13a, 18b.
Since the magnetic poles 3b are separated from the magnetic recording medium 11, there are advantages and disadvantages such as poor convergence efficiency of the return magnetic flux to the auxiliary magnetic poles 13a and 13b, resulting in poor recording and reproducing efficiency.

In any of the magnetic heads, apart from the second advantage, there are contradictory problems between countermeasures against noise and improvement of recording and reproducing efficiency of the magnetic head. Therefore, there is a need for a magnetic head with a structure that has good recording and reproducing efficiency, low noise, and eliminates unnecessary recording and reproducing functions.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a perpendicular recording magnetic head which solves the problems of the prior art and has a structure with high recording and reproducing efficiency and low noise.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a magnetic head having a structure in which a main magnetic pole core and an auxiliary magnetic pole core are integrally joined at one end, in which the auxiliary magnetic pole core is connected to the main magnetic pole core of a non-magnetic protective substrate. A soft magnetic film having a single layer or multilayer structure extends from the surface facing the magnetic recording medium to a predetermined position at opposing ends, and on the surface facing the magnetic recording medium, the area of the soft magnetic film is larger than that of the nonmagnetic protective substrate. It is characterized by having a structure in which the soft magnetic film is sufficiently smaller than the area of , and the soft magnetic film is non-parallel to the main magnetic pole.

It is preferable that the thickness of the soft magnetic film serving as the auxiliary magnetic pole be 10 to 500 μm. If it is less than 10 tIm, the efficiency as a magnetic flux return bus will decrease, and if it is more than 500 μm, the influence of noise from the recording medium will increase. However, if this soft magnetic film has a multilayer structure, eddy current loss can be reduced and magnetic permeability can be expected to be improved.

The soft magnetic film materials used for the main magnetic pole and auxiliary magnetic pole include:
Permalloy (Ni-Fe alloy), Sendust (Fe-A
A material having high saturation magnetic flux density and high magnetic permeability, such as N-S1 alloy) or an amorphous magnetic alloy, is used. In particular, in the case of the main pole, the thickness is very thin, 1 μm or less, so it is desirable to use a magnetic material with a high saturation magnetic flux density in order to prevent magnetic saturation.

In the above, the nonmagnetic protective substrate is made of a ceramic material such as zirconia, alumina carbide titanate, calcium titanate, a single crystal material with high hardness such as sapphire, or crystallized glass, and is used for sliding movement with the magnetic recording medium. Ensures sliding resistance and wear resistance, as well as mechanical strength of the magnetic head core.

The soft magnetic film located at the end of the nonmagnetic protective substrate serves as a return path for the magnetic flux generated from the main magnetic pole, so this soft magnetic film serves as the auxiliary magnetic pole. Therefore, like the main pole, this soft magnetic film is made of a metallic magnetic material having high magnetic permeability and high saturation magnetic flux density. This solves the problem of sliding noise generated in magnetic heads made of ferrite. For the soft magnetic film that will become the auxiliary magnetic pole, a tangential groove is provided on the non-magnetic protective substrate, and the end face where the groove is located is sputtered.
It is formed by vapor deposition or the like. At this time, the shape of the winding groove is adjusted to reduce the magnetic resistance of the formed soft magnetic film.
It is preferable to have gentle corners, and the depth of the groove should not be filled by the molded soft magnetic film.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 8. First, FIGS. 1 and 2 are a perspective view of a magnetic head according to the present invention and a plan view of the magnetic head facing a magnetic recording medium.

In FIG. 1, a main pole core 21 includes a main pole 22 having a high saturation magnetic flux density, main pole auxiliary magnetic materials 23a and 23b made of bulk material such as Mn-Zn ferrite, and main pole auxiliary magnetic materials 23a and 23b made of lead glass or the like. It is constructed by being sandwiched from both sides by main pole auxiliary cores 30a and 30b made of magnetic materials 24a and 24b.

The thickness of the main magnetic pole 22 affects the linear recording density, so in order to perform high-density recording, it is necessary to reduce the film thickness Tm to 1 pm or less. A material having a saturation magnetic flux density is used. Thin film forming techniques such as sputtering and vapor deposition are used to form the main pole 22, and the track width Tw can be precisely processed by patterning the formed main pole film using a photoetching method.

Next, the auxiliary magnetic pole cores 20a and 20b are provided with a non-magnetic protective base 26.
Grooves for winding are formed in a and 26b, and the non-magnetic protective base 26
Auxiliary magnetic poles 25a and 25b are formed on the end faces including the inner wall of the groove between the magnetic recording medium facing surface and the rear end of the magnetic recording medium facing surfaces of the magnetic recording medium facing surfaces 25a and 26b, and lead is formed on the end facing the main magnetic pole core 21 on the magnetic recording medium facing surface side. It is filled with non-magnetic materials 28a and 28b such as glass.

The non-magnetic protective substrates 26a and 26b are made of a material such as zirconia, sapphire, or carbide alumina titanate, which has good sliding resistance against the magnetic recording medium.

In addition, the auxiliary magnetic poles 25a and 25b are made of permalloy, sendust, or an amorphous magnetic alloy in a single layer or multiple layers by sputtering, vapor deposition, or other thin film forming techniques, just like the main magnetic poles.

The thickness of the auxiliary magnetic poles 25a and 25b is 1Opm to 500tI
It is preferable that the length be less than 108 m, and the efficiency as a magnetic flux return bus will deteriorate, and if it is more than 5001 m, the influence of noise from the recording medium and the outside will become undesirable.

Note that the auxiliary magnetic pole 25a formed on the inner wall of the winding groove,
Since the magnetoresistance becomes large at the angle of magnetoresistance 25b, it is preferable to make the angle of the groove as obtuse as possible to reduce the magnetoresistance.

The main [14 core 21 and auxiliary magnetic pole cores 20a and 20b formed as described above]
A and 20b are joined and integrated from both sides by bonding layers 31 made of resin, glass, etc. to form a rad core. Note that the excitation coil is the main magnetic pole core 21 or the auxiliary magnetic pole core 20a.

20b.

FIG. 2 shows the magnetic recording medium facing surface of the magnetic head according to the present invention. The auxiliary magnetic poles 25a and 25b are non-magnetic protective bases 26
The ends of a and 26b facing the main magnetic pole 22 are formed in a convex shape with respect to the main magnetic pole 22, and have no parallel portion to the main magnetic pole 22. By doing so, it is possible to prevent unnecessary recording and reproducing on the ridges of the auxiliary magnetic poles 25 and 26 facing the main magnetic pole.

Further, the non-magnetic materials 24a and 24b are made of a hard material such as hard glass or zirconia for mechanically protecting the main material 22. Non-magnetic material 28a.

28b is made of a hard nonmagnetic material similar to or different from the nonmagnetic materials 24a and 24b to prevent step wear and uneven wear on the surface facing the magnetic recording medium.

3 to 8 are plan views of the surface facing a magnetic recording medium showing other embodiments of the magnetic head of the present invention.

FIG. 3 shows an auxiliary magnetic pole 25a facing the main magnetic pole 22.

The ridge portion 25b is formed in a convex shape with respect to the main magnetic pole 22, and the tip of the convex portion is rounded. In this way, even if the tips are rounded, the main magnetic pole 22 and the auxiliary magnetic pole 25a.

Since the magnetic poles 25b are not parallel to each other on the surface facing the magnetic recording medium, it is possible to prevent unnecessary recording and reproduction on the ridges of the auxiliary magnetic poles 25a and 25b.

FIG. 4 shows a configuration in which the ridges of the auxiliary magnets 1j25a, 25b are formed in a convex shape with respect to the main magnetic pole, and the tips of the ridges are disposed outside the track. Minute main magnetic pole 2 at the tip of the convex part
Although there is a parallel portion to the auxiliary magnetic poles 25a and 25b, since this minute parallel portion is located outside the track, unnecessary recording and reproducing can be prevented on the ridges of the auxiliary magnetic poles 25a and 25b.

FIG. 5 shows the auxiliary magnetic poles 25a, 25b and the non-magnetic material 28a,
A reaction prevention film 29a is provided between the film 28b and the film 28b.

This is a magnetic head having a structure in which 29b is provided. Non-magnetic material 2F
When 3a and 28b are filled with high temperature and highly reactive material such as lead glass, the auxiliary magnets 125a and 25b
It is conceivable that the magnetic properties may be affected by the non-magnetic materials 28a and 28b, resulting in deterioration of the magnetic properties. Therefore, the reaction prevention film 29a,
29b, auxiliary magnetic poles 25a, 25b and non-magnetic 28a
, 28b can be prevented. For the reaction prevention films 29a and 29b, a non-magnetic metal material with weak reactivity such as Cr and Cu is used.

FIG. 6 shows a magnetic head in which the ridges of the auxiliary magnetic poles 25a and 25b are formed in a concave shape with respect to the main magnetic pole. Also in this configuration, since the ridges of the main magnetic pole 22 and the auxiliary magnetic poles 25a, 25b are not parallel, unnecessary recording and reproduction can be prevented on the ridges of the auxiliary magnetic poles 25a, 25b.

FIG. 7 is a perspective view showing another embodiment of the perpendicular recording magnetic head of the present invention, and FIG. 8 is a plan view of the magnetic head facing the magnetic recording medium. This perpendicular recording magnetic head is shown in Figs.
The non-magnetic material 24b in FIG. 6 is omitted, and the auxiliary magnetic pole 25b is moved closer to the main magnetic pole 22 in order to appropriately adjust the distance ML between the main magnetic pole 22 and the auxiliary magnetic pole 25b.

This structure is constructed by sandwiching the main magnetic pole 22 between the main magnetic pole auxiliary core 30 and the auxiliary magnetic pole core 20b.
The distance I5 between the auxiliary magnetic pole 25b and the auxiliary magnetic pole 25b can be made infinitely close. Here, L is suitably 20 to 200 μm. 2
If it is closer than 0 .mu.m, it is not preferable because the shunt of the magnetic flux becomes large, and if it is 200 .mu.m or more on the - side, it is not preferable because the return efficiency of the magnetic flux decreases.

Next, an example of a method for manufacturing the perpendicular recording magnetic head of the present invention will be described below. FIGS. 9 to 12 are explanatory diagrams of the method for producing the perpendicular recording medium of the present invention shown in FIG. 3.

FIG. 9 shows an example of the method for manufacturing the main pole core of the perpendicular recording magnetic head of the present invention. The method for manufacturing the main pole core will be described in the order of numbers (A) to (G) in the figure.

(A) A groove for filling a non-magnetic material is formed in the magnetic core 23 made of a magnetic bulk material such as Mn--Zn ferrite or Ni--Zn. (B) This groove is filled with a non-magnetic material 24 such as lead glass, and the upper surface is polished. (C) This core is cut at a predetermined position, and one side surface is polished to obtain the main pole auxiliary core 30. (
D) The main pole 22 made of a magnetic material having a high saturation magnetic flux density is coated on the polished surface of one of the main pole auxiliary cores 30 using a thin film forming technique such as sputtering or vapor deposition.

(E) The main magnetic pole 22 is etched to a predetermined track width Tw using a pattern forming technique such as dry etching or wet etching.
The main magnetic pole 22 is formed by patterning. (F) The other main pole auxiliary core 30b is bonded to the main pole auxiliary core 30a on which the main pole 22 is formed via a bonding layer 31 made of resin, glass, or the like. (G) Both side surfaces are polished to form the main pole core 21.

FIG. 10 shows another method of manufacturing the main pole core.

The manufacturing steps (A) to (H) will be explained.

(A) A groove for filling a non-magnetic material is formed in the magnetic core 23 made of a magnetic bulk. (B) Non-magnetic material such as lead glass in the groove 2
4 and polish the top surface.

(C) The core is reversed and polished until the filled non-magnetic material 24 is exposed, thereby producing the main pole auxiliary core 30. (D)
A main pole film 22 made of a magnetic material having high saturation: magnetic flux density is formed on the upper surface of the main pole auxiliary core 30 to a predetermined main pole film thickness Tm using a thin film forming technique such as sputtering or vapor deposition. (E) The main magnetic pole 1lI22 is patterned to a predetermined track width T'w using a pattern forming technique such as dry etching or wet etching to form the main magnetic pole 22.

(F) Another main pole auxiliary core 30 is bonded to the main pole auxiliary core 30 on which the main pole 22 is formed using resin and glass. (G) Cut this core at a predetermined position. (H) Polish both sides of the cut core, and
Set to 1.

Next, a method for manufacturing an auxiliary magnetic pole core for a perpendicular recording magnetic head according to the present invention will be explained according to manufacturing steps (A) to (D) in FIG. 11.

(A) A groove for winding is formed in the nonmagnetic substrate 26.

(B) A groove for filling a nonmagnetic material is formed in the upper end of the nonmagnetic substrate 26 to produce a nonmagnetic protective substrate 26. In this case, as shown in (B)-2, the groove is formed in a tapered shape that is inclined downward toward the outside in the width direction. (C
) The auxiliary magnetic pole 25 made of a soft magnetic material is formed into a single layer or a multilayer film using a thin film forming technique such as sputtering or vapor deposition on a single surface of the nonmagnetic protective substrate 26 in which grooves for winding are formed.

The thickness of the auxiliary magnetic pole 25 is 10 to 500 um.

(D) The groove formed in the above (B) is filled with a non-magnetic material made of lead glass or the like, and the upper surface is polished to form the auxiliary magnetic pole 20.

FIG. 12 is an explanatory diagram of a method for manufacturing the perpendicular recording magnetic head of the present invention from the main pole core and auxiliary pole core manufactured by the above method.

The manufacturing procedures (A) and (B) will be explained.

(A) The main magnetic pole core 21 and the two auxiliary magnetic pole sides 20a, 2Qb obtained by the above method are formed by bonding the auxiliary magnetic pole sides 20a, 20b to both sides of the main magnetic pole film 21 using resin, glass, etc. This becomes an individual magnetic held core 40. (B) The multi-piece magnetic head core 40 is cut at predetermined positions to obtain the perpendicular recording magnetic head of the present invention.

〔Effect of the invention〕

The present invention has the following effects in a magnetic head having a main pole and an auxiliary pole as a perpendicular recording magnetic head.

(1) Sliding noise can be reduced by using a metallic magnetic material for the auxiliary magnetic pole, which was conventionally made of ferrite.

(2) By reducing the volume occupied by the auxiliary magnetic pole, noise reproduced through the recording medium and external noise can be reduced.

(3) Most of the opposing surface of the recording medium is made of a non-magnetic protective substrate with excellent sliding resistance, so that wear due to sliding can be reduced.

(4) Since the auxiliary magnetic pole is close to the recording medium, there is no deterioration in magnetic flux convergence efficiency due to spacing (and recording/reproducing efficiency is good).

(5) By making the main magnetic pole and the auxiliary magnetic pole non-parallel on the surface facing the recording medium, unnecessary recording and reproduction at the auxiliary magnetic pole can be prevented.

As described above, according to the present invention, a magnetic head with excellent recording and reproducing characteristics and high reliability can be obtained.

[Brief explanation of the drawing]

1 is a perspective view showing an embodiment of the perpendicular recording magnetic head of the present invention, FIG. 2 is a plan view showing the medium facing surface of the magnetic head of FIG. 1, FIGS. 3, 4, and 5. Figure and 6th
The figures are perspective views showing other embodiments of the magnetic head according to the present invention, FIG. 7 is a perspective view showing another embodiment of the magnetic head for perpendicular recording of the present invention, and FIG. 8 is a perspective view of the magnetic head of FIG. 7. FIGS. 9, 1O, 11 and 12 are process diagrams showing the manufacturing procedure of the magnetic head of the present invention, and FIGS. 13 and 14 are perspective views showing the medium facing surface of the conventional magnetic head. FIG. 2 is an explanatory diagram of a recording magnetic head. 20... Auxiliary magnetic pole core, 21... Main magnetic pole core, 22... Main magnetic pole, 23a, 23b...
...Main pole auxiliary magnetic material, 24a, 24b...
...Nonmagnetic material, 25a. 25b...Auxiliary magnetic pole, 26a, 26b...
...Nonmagnetic protective substrate, 28a, 28b...Nonmagnetic material, 30a. Agent Patent Attorney Kenji Take Department Figure 1 Section 2 /(゛) 28a 2231 28b Figure 3 28a22 31 28b Figure 7 Figure 8 Figure 9 Factor η Figure 11 Δ (B)-2 Figure 12 (A) Comparison (B)

Claims (2)

[Claims] (1) In a magnetic head having a structure in which a main magnetic pole core and an auxiliary magnetic pole core are joined and integrated, the auxiliary magnetic pole core has a non-magnetic protective substrate and a magnetic recording medium on the end surface of the non-magnetic protective substrate facing the main magnetic pole. a soft magnetic film with a single-layer or multilayer structure extending from the opposing surface to a predetermined position, and on the surface facing the magnetic recording medium, the area of the soft magnetic film is sufficiently small, and the magnetic recording of the soft magnetic film is performed. A perpendicular recording magnetic head characterized in that an end face facing a medium is non-parallel to an end face of a main pole. (2) The perpendicular recording magnetic head according to claim (1), further comprising a reaction prevention film made of a non-magnetic material on an end face of the soft magnetic film facing the main pole. .