JPS61129710A - Vertical magnetic recording head - Google Patents

Abstract

PURPOSE:To make compatible high-density recording and the improvement in recording and reproducing sensitivity by forming a main magnetic pole film into the laminated structure consisting of the 1st main magnetic pole film having high magnetic permeability and high saturation magnetic flux density and the 2nd main magnetic pole film having the magnetic permeability lower than the magnetic permeability of the 1st main magnetic pole film and the low saturation magnetic flux density. CONSTITUTION:The main magnetic pole film is formed by laminating the 1st main magnetic pole film 11A and 2nd main magnetic pole film 11B having respectively different magnetic characteristics, i.e., saturation magnetic flux density and high-frequency magnetic permeability. A soft amorphous magnetic film is used for the 1st main magnetic pole film 11A and a 'Cu-Mo Permalloy(R)' film is used for the 2nd main magnetic pole film 11B. The saturation magnetic flux density can be substantially increased even in the stage of recording according to the above-mentioned formation and therefore the magnetization saturation with the decreased film thickness of the main magnetic pole film can be averted. The satisfactory magnetization of the recording medium is made possible even in the case of executing the magnetization of the recording medium at high density. The high density recording medium and the improvement in the recording and reproducing sensitivity are thus made compatible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) This invention relates to a g & air head used in a magnetic recording device;
In particular, it relates to perpendicular magnetic recording heads used in perpendicular magnetic recording/reproducing devices, which have recently attracted attention as a recording method suitable for high-density recording. (Prior art) A typical magnetic head for superimposed magnetic recording that has been proposed in the past has the structure shown in Fig. 6l. There is an auxiliary magnetic pole excitation type single magnetic pole head.

In this magnetic head, as is well known, the main pole has a main pole film 11 and a main pole film holding material 12.

12B, it is constructed by adhesively holding it in a sandwich-like manner.

Moreover, so as to sandwich the recording medium 15 and face the main magnetic pole,
An auxiliary magnetic pole 13 is arranged, and an input/output winding 14 is wound around the auxiliary magnetic pole 13. The recording medium 15 is conveyed between the main magnetic pole and the auxiliary magnetic pole 13, for example in the direction indicated by the arrow.

(Problems to be Solved by the Invention) The above-described conventional techniques had the following problems.

In the above-described magnetic head, the magnetic properties and dimensions of the main pole film 11 greatly affect the information recording and reproducing characteristics. The magnetic properties of the main pole film 11 are that it has a large maximum magnetic flux density and a large magnetic permeability. Advantageously, this allows the recording input/output sensitivity to be improved.

Further, the film thickness at the tip end of the main pole film 11, that is, at the pole surface side, is directly related to the resolution during reproduction.

As is often said, in order to realize reproduction of magnetized media recorded at high density, it is necessary to
It is necessary to make the thickness of the main pole film 11 on the pole surface side as thin as possible.

In perpendicular recording and reproduction using a conventional perpendicular magnetic recording head as shown in FIG. In other words, the maximum recording density was a density corresponding to approximately 0.5 .mu.r114) bit length, and this was called the first dip point of the recording density.

p) As is clear from the foregoing, if the thickness of the main pole film 11 is made thinner, the magnetic resistance increases and the effective magnetic permeability also decreases, resulting in a decrease in the recording and reproducing sensitivity. That is, the conventional technology has the drawback that it is not possible to achieve both high-density recording and improvement in recording and reproducing sensitivity.

The present invention has been made to solve the above-mentioned problems.

(Means and effects for solving the problem) The present inventors have been conducting extensive research on perpendicular magnetic recording and reproducing devices for many years. A perpendicular magnetic recording head that can simultaneously improve the performance of the magnetic recording medium, or a magnetic reproducing device that can reproduce medium magnetization with a bit length corresponding to the dip point, which cannot be reproduced using normal perpendicular recording reproduction methods. The perpendicular magnetic recording head, which was invented and a patent application has already been filed, is disclosed in Japanese Patent Application No. 100755-1988, Shishu-sho.
Further, the magnetic reproducing device is disclosed in Japanese Patent Application No. 58-100743.
They are described in the specification of each issue.

The perpendicular magnetic recording head described in the specification of Japanese Patent Application No. 58-1007515 has a main magnetic pole film formed so that the thickness of the portion near the magnetic pole surface is substantially reduced. Despite the thinness of the main pole film at the magnetic pole surface, the magnetic resistance of the entire main pole film can be reduced, and the maximum magnetic flux density can be increased. It is possible to simultaneously improve reproduction sensitivity.@ The present invention solves the above-mentioned problems by means different from the perpendicular magnetic recording head described in the above specification.

In order to solve the above problems, the present invention provides a first main magnetic pole film with high magnetic permeability and high saturation magnetic flux density, and a first main magnetic pole film with lower magnetic permeability and lower saturation than the first main magnetic pole film. The main pole film is formed in a laminated structure consisting of a second main pole film with a high magnetic flux density. The feature is that the effective thickness can be reduced, thereby achieving the effect of achieving both the aforementioned high-density recording and improved recording/reproducing sensitivity. Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a first embodiment of the invention.

In this figure, the same reference numerals as in FIG. 5 represent the same or equivalent parts.

The main pole films of the first embodiment of the present invention are magnetically custom-made, that is, the first main pole film 11 and the second main pole film 11 have different saturation magnetic flux bands 11iJ5 and high frequency magnetic permeabilities.
It is formed by laminating B.

The main magnetic pole film formed in the laminated structure is held between 12 main magnetic pole film holding members and 12B. High frequency permeability 8000,
Co@. An amorphous soft magnetic film having a -zrlo composition is used, and as the main magnetic pole film 11B of the wc2, a Cu-M
An experiment was conducted using o permalloy membrane.

In addition, 11 people were involved in the ftgl and the second main magnetic pole film.

The thicknesses Bl and B2 of 11B are each 0.2 pro,
Next, the individual recording rM seismic intensity - raw output (voltage) of the first main magnetic pole 1 la 11 and the second main magnetic pole film 11 B having the above-mentioned magnetic properties and thickness were custom made. Second
As shown in the figure.

In Figure 2, the horizontal axis is the recording density, and the vertical axis is each main li.
The reproduction voltages are normalized so that the maximum weight of the reproduction voltages of the a-pole films are both the same value.

In addition, song 1111 is a 0.2 μm thick amorphous film,
Curve IsF shows the characteristics of a 0.8 μm thick permalloy film.

As is clear from Fig. 2, for example, the recording density is 100
At KBPI (kilobit per inch), a permalloy film with a film thickness B2 of 0.8 μm (i.e., the second main pole film 11B) does not provide sufficient output.
In other words, although magnetization reversal is not performed much, an amorphous film with a film thickness B1 of 0.2 μm (i.e., the first
With the main magnetic pole film (11 people), almost the same output was obtained as when the recording density was low.

In this case, when an amorphous film with a film thickness B1 of 0.2 μm and a permalloy film with a film thickness B2 of 0.8 μm are laminated as shown in FIG. Due to the reversal, the magnetization is reversed in the same direction as the direction of magnetization reversal of the amorphous film.

Note that in FIG. 2, the reproduction voltage of each characteristic curve is normalized as described above, so for example, it is 0.8μ.
When permalloy film with a thickness of m is used alone (Track 411
F) When reproducing data near the recording density corresponding to the dip point, the reproducing voltage may exceed the reproducing voltage when a 0.2 μm thick amorphous film is used alone (curve Fl).

However, since magnetization reversal is strongly influenced by the strength of the magnetic field, even in the above case,
The magnetization reversal of the amorphous film further causes the magnetization reversal of the permalloy film. FIG. 3 shows the recording density-reproducing output (voltage) characteristics of the magnetic recording head laminated as described above.

In FIG. 3, the horizontal axis shows the recording density, and the vertical axis shows the reproduction voltage.

Curve E shows a case in which a 0.2 μm thick amorphous film is used alone as the main pole film, and curve G shows a stack of a 0.2 μm thick amorphous film and an O, S μm thick permalloy film as the main pole film. ◇ In general, the reproduction output of a perpendicular magnetic recording head is proportional to the total reversal magnetic flux of the main pole film. In the first embodiment of the invention, it was possible to obtain approximately three times the reproduction output compared to the case where a 0.2 μm thick amorphous film was used alone as the main pole film. The 8N ratio of playback output is also extremely high)
In addition, the first embodiment of the present invention described above can substantially increase the saturation magnetic flux density even during recording, so that the thinning of the main pole film and the accompanying magnetization saturation can be reduced. This phenomenon can be avoided, and even when the recording medium is magnetized at high density, the recording medium can be sufficiently magnetized.

As is clear from the above description, the first embodiment of the present invention can achieve both high-density recording and improved recording/reproduction sensitivity. Figure 4 shows the second embodiment of the present invention. ◇ This is a schematic cross-sectional view showing the main magnetic pole. In the figure, the same reference numerals as in FIG. 1 refer to the same or equivalent parts.

As is clear from Figure g4, the second embodiment of the present invention is
The first main magnetic pole film 11 is placed on both sides of the first main magnetic pole film 11.
The second type has lower saturation magnetic flux density and high frequency permeability than humans.
The main magnetic pole film 11B has a three-layer structure in which the main magnetic pole film 11B is formed in the shape of a sandwich weasel. In this case as well, the main magnetic pole film 11B is similar to the first example of the SGT described above (this,
High-density recording and improved recording/reproducing sensitivity can be achieved at the same time. In the above description, the present invention was applied to a head of an auxiliary magnetic pole excitation disk.

It goes without saying that the present invention is not limited to this, and may be applied to a main pole excitation type head.

(Effect) As is clear from the above explanation, one shot f! According to Atζ, the following effects are achieved: (1) Since it is easy to reduce the effective thickness of the main pole film on the pole surface, it is possible to increase the reproducible recording density. can.

(2) Since the magnetic resistance of the entire main pole film can be reduced, the maximum magnetic flux density can be reduced, and the recording and reproducing sensitivity can be increased.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the first embodiment of the present invention, and FIG. 2 is a graph showing the recording density-reproduction voltage characteristics of a 0.2 μm thick amorphous film and a 0.8 μm thick permalloy film. Figure 3 shows the recording density vs. read voltage of a main pole film using a 0.2 μm thick amorphous film alone and a product of a 0.2 pm thick amorphous film and an O0Bpm thick permalloy film. Graph showing custom order, FIG. 4 is a sectional view showing the main pole of the second embodiment of the present invention, and FIG. 6 is a sectional view showing an example of a conventional perpendicular magnetic recording head. Membrane, 11 people...first main pole membrane. 11B...Second main magnetic pole film, 12 people, 12B...Main magnetic pole film holding material, 1t...Recording medium agent Patent attorney Michihito Hiraki (1 other person) Figure 1 Figure 4 Figure 2 Third cause

Claims (3)

[Claims] (1) A perpendicular magnetic recording head comprising a non-magnetic substrate and a main pole film formed on the non-magnetic substrate, wherein the main pole film has a high magnetic permeability and a high saturation magnetic flux density. 1. A perpendicular magnetic recording head having a laminated structure comprising a first main pole film and a second main pole film having lower magnetic permeability and lower saturation magnetic flux density than the first main pole film. (2) The perpendicular magnetism according to claim 1, wherein the laminated structure is a three-layer structure in which the second main pole film is stacked on both sides of the first main pole film. recording head. (3) The perpendicular magnetism according to claim 1, wherein the laminated structure is a two-layer structure in which the second main pole film is stacked on one side of the first main pole film. recording head.