JPS6350905A - Perpendicular recording magnetic head - Google Patents

Abstract

PURPOSE:To obtain a perpendicular recording magnetic head with high durability, and high recording and reproducing sensitivity, by providing a cavity in which foreign matters can be received, at the front and rear in a direction of moving the magnetic recording medium of the main magnetic pole of the magnetic head. CONSTITUTION:A recording and reproducing main magnetic pole 42, and an erasing main magnetic pole 43 consisting of thin films with high permeability of small area are formed interposing a supporting body 41, at the oppositely installed side of the magnetic recording medium. Auxiliary magnetic poles 44 and 45 made of soft magnetic material forming the return path of magnetic flux are provided between the magnetic recording medium, and the main magnetic poles 42 and 43, keeping a wide opposing area to the magnetic recording medium. Core parts 44b and 45b on which recording and reproducing coils C and C are loaded, are formed at the main magnetic poles 42 and 43, and the auxiliary magnetic poles 44 and 45. Sliding bodies 46 and 47 made of nonmagnetic material are stuck on the upper planes 44c and 45c at the sliding sides of the auxiliary magnetic poles 44 and 45, on which the vertical recording magnetic head is constituted. The cavities 48 and 49 to receive the foreign matters are provided at the front and rear in the direction of moving the magnetic recording mediums of the main magnetic poles 42 and 43. In this way, dirts, etc., are captured in the cavities, and crush due to the foreign matters of the head, etc., can be prevented, and thereby, the durability of a device can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a perpendicular recording magnetic head that records and reproduces information on a magnetic recording medium using a perpendicular magnetic recording method.

[Prior art and its problems] In recent years, with the improvement of magnetic recording density, a perpendicular magnetic recording method has been proposed in which the demagnetizing field for recording magnetization transition is small and the stability of magnetization is increased as a result of high-density recording. Kaisho 52-1
34706, JP-A-53-3209)
.

Although this method has the advantage of being capable of high-density magnetic recording, it requires a magnetic recording medium with perpendicular anisotropy and a magnetic head with a strong magnetic field in the perpendicular direction.

FIG. 6 shows an example of the configuration of a conventional magnetic head. In the figure, a magnetic recording medium 10 is a well-known perpendicular magnetic recording medium, in which a soft magnetic layer 12 having high magnetic permeability such as permalloy and a perpendicular anisotropy film such as a C0Cr alloy film are sequentially coated on an 11 surface of a substrate such as a polymer film. A perpendicular magnetization layer 13 having a perpendicular magnetization layer 13 is formed.

A main pole core 21 made of a high magnetic permeability thin film with a film thickness Tm is placed adjacent to the magnetic recording medium 10 in the first and second non-magnetic blocks 2.
The main magnetic pole part 20a and the magnetic recording medium 10 sandwiched between 2 and 23
A magnetic head has been proposed that is formed of an auxiliary magnetic pole portion 20b consisting of an auxiliary magnetic pole core 24 made of a high magnetic permeability material and a recording/reproducing coil 25 sandwiched therebetween.

In the reproducing operation of this conventional magnetic head, the magnetic flux from the magnetization recorded in the perpendicular magnetic layer 13 becomes a magnetic flux that circulates in the open magnetic circuit 26 shown by the dotted line, and changes across the recording and reproducing coil 25, so that the magnetic flux is not used for recording and reproducing. This is done by converting the signal into an electrical signal using the coil 25.

Further, the recording operation is performed by generating a magnetic flux that circulates around the magnetic circuit 26 using an electric signal from the recording/reproducing coil 25 to magnetize the perpendicular magnetic layer 13 and record data, contrary to the above.

However, the configuration of the magnetic head shown in FIG. 6 has the following drawbacks.

The thickness Tm of the main pole core 21 is determined by the minimum width of the transition width of the perpendicular magnetization layer 13 to be reproduced, and therefore it inevitably becomes smaller in high-density recording. For example, the recording density is 100KFRPI.
(Kilo Flux Reversalper
Inch), Tm needs to be 0.4 μm or less, so the magnetic resistance of the main pole core 21 increases. For this reason, there are disadvantages in that the recording/reproducing sensitivity is lowered and the head is more susceptible to the influence of a slight magnetic field near the head. This is thought to be due to the head structure, which has a large magnetic resistance because the magnetic circuit 26 returns through the air, and the magnetic flux that crosses the coils is small, which particularly tends to reduce the reproduction sensitivity.

The head structure shown in FIG. 7 has been proposed as a head structure that eliminates the drawbacks shown in FIG. That is, in order to prevent an increase in the magnetic resistance of the main magnetic pole core 31 made of a high magnetic permeability thin film having a film thickness of 1"m, a second high magnetic permeability block 3 is installed horizontally in the direction of the track width 1w.
Place 5.

Also, a portion corresponding to the track width TW (Fig. 7(b))
The structure is such that a main pole core 31 is held by a nonmagnetic layer 32 and a nonmagnetic block 33 having a thickness of Dl, and a sufficiently strong magnetic field perpendicular to the perpendicular magnetic layer 413 can be generated.

Further, by arranging the first high magnetic permeability block 34 and the third high magnetic permeability block 36 via the nonmagnetic layer 33, the magnetic circuit 37 is closed, and the open circuit shown in FIG. Problems with magnetic circuits are eliminated.

In the head structure proposed in Fig. 7, the magnetic circuit between the head and the medium becomes a closed circuit, and the sensitivity of recording and reproduction can be improved. 31 as well as the surface of the perpendicular magnetization 1ii13 of the magnetic recording medium 10.

In the case of the head structure in FIG. 7, the perpendicular recording layer 13
The sliding abrasion properties of the high magnetic permeability bodies 34 and 35 in contact with the high magnetic permeability bodies are limited by the material properties of the high magnetic permeability bodies. In particular, when a co-Cr layer, which is excellent as a perpendicular magnetic recording medium, is used as the perpendicular magnetic layer, only the main pole core 21 slides on the perpendicular recording layer 13, as shown in the structure shown in FIG. In order to form a head with excellent durability, the sliding surface must be constructed using a non-magnetic block made of a ceramic material with excellent wear resistance and lubricity.

``Object of the Invention'' The present invention was made in view of the current situation, and an object of the present invention is to provide a perpendicular recording magnetic head that has excellent durability and high recording and reproducing sensitivity.

[Structure and operation of the invention] That is, the present invention provides a main magnetic pole in a recording/reproducing part of a magnetic recording medium, the side facing the magnetic recording medium being made of a thin film with high magnetic permeability and a small area, and An auxiliary magnetic pole made of a soft magnetic material that is magnetically coupled on the opposite side to form a magnetic flux return path between the magnetic recording medium and the main magnetic pole, and whose surface facing the magnetic recording medium has a large area; In a perpendicular recording magnetic head comprising a recording/reproducing coil provided on a magnetic pole or an auxiliary magnetic pole, and a sliding body made of a non-magnetic material provided on an opposing surface of the auxiliary magnetic pole, the magnetic recording medium of the main magnetic pole is This is a perpendicular recording magnetic head characterized by having a gap for accommodating foreign matter provided in at least one of the front and rear sides of the moving direction.

As mentioned above, in the present invention, an air gap is provided at least on either side of the front or rear of the main magnetic pole, and foreign matter such as dust or abrasion powder is captured by the air gap, so that the sliding surface is kept clean by self-cleaning and the head Therefore, the durability of the head and magnetic recording medium is greatly improved, and the sliding motion is stabilized and the recording/reproducing characteristics are stabilized.

Therefore, the gap may be of any size as long as it can receive and trap foreign matter, and its width may normally be 10 μm or more, and preferably several 100 μm or less in terms of stable running. The length preferably covers the entire sliding portion with the magnetic recording medium, and is therefore preferably longer than the width of the main pole.

In the above-mentioned invention (a), the main pole is preferably made of a soft magnetic thin film, and in particular, a soft magnetic thin film formed on the side surface of the support plate made of a non-magnetic material is preferably used from the viewpoint of manufacturing and durability. As the soft magnetic thin film, a known high magnetic permeability material such as Permalloy, Sendust, GO-based amorphous alloy, etc. is used. Since the support constitutes a sliding surface, all materials known as slider materials for magnetic heads can be applied.
A sliding material that has good surface workability to ensure the formation or adhesion of the main pole, and does not have a large difference in hardness from the high magnetic permeability material that will become the main pole, specifically a Vickers hardness difference of less than a few hundred. Therefore, a slider material having a Vickers hardness of 1100 or less is preferably used. Such materials include glass and non-magnetic ferrite ceramics.

Examples include calcium titanate, potassium titanate, barium titanate, Mn 0 -Ni 2 O, crystallized glass, and the like. Crystallized glass (e.g. Nippon Electric Glass ■ C-9)
has a Vickers hardness of 1030, which is preferable in terms of wear resistance. Glass-based and non-magnetic ferrite-based ceramics have a Vickers hardness of 600 to 700, have good workability in comparison with magnetic properties and surface properties, and are suitable for processing the main magnetic pole, so they are preferred.

On the other hand, as with the support, all materials known as slider materials for magnetic heads can be used for the sliding body, but they have good abrasion resistance and can be used in combination with thin-film magnetic recording media to provide durability of several million passes or more. A slider material having a Gockers hardness of 1500 or more is preferable.

Such a slider material includes AlTiC (specifically, AC-2 (trade name) manufactured by Sumitomo Special Metals), etc.

St0-Er02, StC, SiaNa
.

All! 203-Zr 02 and the like, and those subjected to surface hardening treatment with these may also be used. Among them, Altic A
120a-TiC is preferable because it has a hardness of 2000 or more and excellent wear resistance.

Further, it is preferable that the sliding body has a soft magnetic layer formed on the side of the surface to be adhered to the auxiliary magnetic pole, which serves as a path for the return magnetic flux from the magnetic recording medium. Such a soft magnetic layer has the effect of improving recording and reproducing sensitivity. Note that it is preferable that the soft magnetic layer be provided in as wide an area as possible around the main pole without forming a magnetic short circuit with the main pole. This soft magnetic layer can be made of a well-known soft magnetic material such as permalloy.

The details of the present invention will be explained below based on an embodiment of a magnetic disk head.

Fig. 1 is a plan view of the embodiment as seen from the sliding side, Fig. 2 is a side cross section thereof, Fig. 3 is a front view of the main magnetic pole for recording and reproducing, and Fig. 4 is a front view of the main magnetic pole for erasing. It is a diagram.

In the figure, reference numeral 41 denotes the support of the main pole, which is approximately 100 μm thick and consists of an approximately square plate with several corners.
We used Neoceram (registered trademark), a crystallized glass slider material manufactured by Manufacturer. A recording/reproducing main magnetic pole 42 is formed on one surface of the support 41, and an erasing main magnetic pole 43 is formed on the other surface. At the tips of these main magnetic poles 42 and 43, AJj20a films with a thickness of several μm are formed as protective films so and si by RF sputtering, etc., in order to further improve mechanical and chemical durability.

Note that this protective film 50.51 is used as an auxiliary magnetic pole 44.45, which will be described later.
The core portions 44b and 45b are provided on the distal side.

The main magnetic pole for recording/reproducing 42 has a magnetic pole portion 42a having approximately the same width in the track at the tip and a magnetic path portion 42 having a wide width following the magnetic pole portion 42a.
The erasing main magnetic pole 43 consists of a magnetic pole part 43a arranged so as to correspond to both sides of the track, that is, both sides of the recording/reproducing magnetic pole part 42a, and a wide magnetic path part 43b following the magnetic pole part 43a. Both are made of amorphous magnetic thin films of CoNbZr alloy.

Then, a plate-shaped main body portion 4 having approximately the same external shape as the support body and a predetermined thickness is provided.
4a and 45a, there is a columnar core portion 44b which serves as a coil mounting portion in a communication magnetic path with the main magnetic pole 42, 43.

The tip surfaces of the core portions 44b and 45b are attached to the main magnetic pole 42 so that the side of the auxiliary magnetic poles 44 and 45 formed with the magnetic recording medium is slightly set back from the tip of the support 41. .43 magnetic path portions 42b, 43b are bonded to the center portions 42c, 43c. In this example, ferrite was used for the auxiliary magnetic poles 42 and 43.

The top surface 44C14 is a diagram of the sliding side of the auxiliary magnetic pole 44.45.
As shown in the figure, plate-shaped sliding bodies 46 and 47 are bonded to 5c. The sliding bodies 46 and 47 are connected to the main magnetic pole 42°4 as shown in the figure.
A portion corresponding to the front and back of the running direction of the magnetic recording medium No. 3 is cut out to a predetermined depth of more than 10 μm over the width of the main magnetic pole 42, 43 to form a support 41 and a main body portion 44a of the auxiliary magnetic pole.
Gaps 48 and 49 are formed through the space formed by 45a. In this example, the sliding body is made of alumina titanium carbide (A, C203-Tf C) (specifically, manufactured by Sumitomo Special Metals @ product name AC-2), and the surface on the auxiliary magnetic pole side is made of soft magnetic permalloy thin film. layer 46a,
47a was formed.

In the figure, the top surface of the support body 41 and the sliding body 46,
A predetermined curved surface that is the same plane as the front surface of 47 (approximately a plane in this example)
The desired sliding surface was formed by polishing.

C+ and C2 in the figure are recording/reproducing and erasing coils, which are attached when assembling the auxiliary magnetic poles 44, 45, etc.

Using the above perpendicular recording magnetic head, we investigated its durability in combination with a flexible disk.

The disk 10 has the same shape as a commercially available 3.5-inch flexible disk, and is made of a perpendicular magnetic recording medium shown in FIG. That is, the flexible film 11 has a surface roughness of 20 in center line average roughness Ra (JISB 0601).
People (A of TENCORIN5TRUMENTS, Inc. in the United States)
measured with lpha 5tep 200), film thickness 50μ
A NiFeMo alloy layer with a thickness of 0.5 μm and a coercive force of about 30 Qe (Oersted) was used as the high magnetic permeability layers 12A and 12B on both sides, and a NiFeMo alloy layer with a thickness of 0.15 μm was used as the recording layers 13A and 13B. Vertical coercive force is 600 Qe, saturation magnetization is 500 emu/c
The Co--Cr alloy layer shown in FIG. 1C is formed by sequentially forming Co 304 with a thickness of 0.02 μm as the protective layers 14A and 14B by facing target sputtering method.

The evaluation device was first developed by the inventors in Japanese Patent Application No. 168514/1986.
Basically, it is the same as the conventional floppy disk drive proposed in the specification, and measures the load applied to the head in the vertical direction of the disk (head load) and the load (frictional force) in the direction of rotation and parallel to the disk. The perpendicular recording magnetic head 40 is set in this.

The test was conducted using a disc 10 housed in a commercially available 3.5-inch flexible disc hard jacket (manufactured by Sony ■).

First, after conducting a durability test of over 6 million passes, changes in the head surface and disk sliding surface were investigated.

As a result, stains were found in the voids of the head, but the surface of the support 41 made of Neoceram and the A pattern 20
On both surfaces of the sliding bodies 46 and 47 made of 3-Ti G, no dirt was visible in the center, and some dirt was observed only at the ends.

In addition, the profile of the head surface was
As a result of checking with a stylus roughness meter manufactured by NSTRUMENT, there was no change before and after the durability test. The profile of the disk sliding surface was also examined in the same way, and the condition of the medium surface was found to be good with almost no change. When a durability test was conducted using a structure in which the gaps 48 and 49 were in close contact with each other as a head, after the 3 million pass test, dirt was scattered on both the surface of the support body 41 and the surface of the sliding bodies 46 and 47. It was found that the head was unreliable.

Also, during the durability test, the head load and head friction were continuously measured and evaluated, and the results are as follows.

In the case of the head configuration of the embodiment of the present invention, the head load (1.5 gr/m
ff1>, there was no change in the fluctuation of the head load accompanying the rotation of the disk, and there was no change in the state of the frictional force (0.6gr/mfA) and its fluctuation.

On the other hand, in the case of the head in which the gap 48.49 was made into a close-contact structure, no change was observed in the head load during the 3 million pass durability test, but the frictional force changed. The width increased by about 30% when the number of passes exceeded 200,000, and the width changed with respect to the number of passes. This phenomenon is considered to be due to abrasion particles and the like subtly changing the sliding condition between the head and the medium.

Although the present invention has been explained above using examples, the present invention is not limited to these examples.

Although a main magnetic pole for erasing is shown, it goes without saying that it may be omitted.

Further, it is clear from the spirit of the present invention that the shape of the head, the shape of the sliding surface, the shape of the auxiliary magnetic pole, and even the mounting location of the coil can be changed as appropriate.

As described above, the present invention can be implemented in various embodiments, and the following various effects can be obtained.

(1) Since a gap is provided in the running direction of the head, contamination and wear particles can be self-cleaned, and a highly durable head can be realized.

(2) Main pole support material has Vickers hardness of 1100
Hereinafter, by having a structure in which the surrounding sliding body has a Vickers hardness of 1500 or more, a head that is easy to process and has good durability can be obtained.

(3) The head tip shape can be made smaller than one cocoon opening,
Stable and reliable contact between head and medium.

(4) A magnetic path is formed around the main magnetic pole, making it resistant to external disturbances and improving recording/reproducing sensitivity.

(5) A compact head with separate recording and reproducing functions can be formed.

(6) The erasing head section required for a flexible disk system can be formed adjacent to the main pole.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the embodiment, Fig. 2 is a side sectional view thereof, and Fig. 3 is a plan view of the embodiment.
The figure is a front view of the main magnetic pole for recording/reproducing, Figure 4 is a front view of the main magnetic pole for erasing, Figure 5 is a side sectional view of the disk used in the test, and Figures 6 and 7 are conventional examples. FIG.

Claims (1)

[Scope of Claims] 1. A main magnetic pole that is a recording/reproducing part of a magnetic recording medium and the side facing the magnetic recording medium is made of a thin film with high magnetic permeability and a small area;
A soft magnetic material that is magnetically coupled to the main magnetic pole on the opposing side and the opposite side to form a magnetic flux return path between the magnetic recording medium and the main magnetic pole, and has a large area facing the magnetic recording medium. A magnetic head for perpendicular recording comprising an auxiliary magnetic pole, a recording/reproducing coil provided on the main magnetic pole or the auxiliary magnetic pole, and a sliding body made of a non-magnetic material provided on the opposing surface of the auxiliary magnetic pole. 1. A magnetic head for perpendicular recording, characterized in that a gap for accommodating foreign matter is provided at least one of the front and rear sides of the magnetic pole in the direction of movement of a magnetic recording medium. 2. The magnetic head for perpendicular magnetic recording according to claim 1, wherein the air gap is provided before and after the main magnetic pole over a width greater than that of the main magnetic pole. 3. A magnetic head for perpendicular magnetic recording according to claim 1 or 2, wherein the sliding body has a soft magnetic layer formed on a surface thereof on the side of the auxiliary magnetic pole to collect the return magnetic flux from the magnetic recording medium. 4. Claim 1, 2 or 3, wherein the main magnetic pole is formed on one surface of a support made of a non-magnetic material.
The magnetic head for perpendicular recording described in . 5. The main magnetic poles are located on both sides of a main magnetic pole for recording/reproducing of a predetermined width provided on one surface of a support made of a non-magnetic material, and a main magnetic pole for recording/reproducing provided on the other surface. 5. The perpendicular recording magnetic head according to claim 4, comprising a main magnetic pole for erasing having a predetermined width, and wherein the auxiliary magnetic pole and the coil are respectively provided on both the main magnetic poles. 6. The perpendicular recording magnetic head according to claim 4 or 5, wherein the sliding surfaces of the support of the main pole and the sliding body are formed into the same curved surface. 7. The main pole support is made of a non-magnetic material with a Vickers hardness of 1100 or less, and the sliding body has a Vickers hardness of 1.
Claim 4 consisting of 500 or more non-magnetic materials,
The perpendicular recording magnetic head according to item 5 or 6.