JPS6059509A - Forming method of main magnetic pole of vertical magnetic recording head - Google Patents

Abstract

PURPOSE:To improve the reliability and performance of a vertical head by impressing the lines of magnetic force vertically to the surface of a head supporting board and controlling the magnetic characteristics of a high permeability thin film used for a main magnetic pole at the formation of the thin film to obtain the thin film having isotropic magnetic characteristics. CONSTITUTION:At the formation of the main magnetic pole of the vertical magnetic recording head by a sputtering method, a vapor deposition method or a plating method, a magnet 14 having its magnetizing axis vertically to a base plate 13 immediately under the base plate 13 is arranged in a circular hole on the center of a base plate holder 12 and the lines 15 of magnetic force vertical to the thin film are impressed during the formation of the high permeability thin film. The magnetic characteristics of the high permeability thin film formed by said procedure is easily isotropic and the reliability and performance of the vertical head can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a main magnetic pole of a perpendicular magnetic recording head (hereinafter referred to as a perpendicular head). The purpose is to increase the reliability of the vertical head and improve its performance by controlling it at the time of creation and making it isotropic.

In recent years, with the demand for higher density magnetic recording, magnetic recording is performed in the thickness direction of a magnetic recording medium. The so-called perpendicular magnetic recording method is attracting attention.

Various types of perpendicular heads have been proposed for use in perpendicular magnetic recording, but basically they consist of a main magnetic pole made of a thin film with high magnetic permeability, a relatively thick auxiliary magnetic pole made of ferrite, etc., and an excitation coil. Composed of j'1. −'
(There is.

Nine typical auxiliary pole excitation type perpendicular magnetic heads among these perpendicular heads are shown in FIG. In this head, during recording, a recording current is passed through the coil (2) to excite the magnetic body (3) of the auxiliary magnetic pole, and this excites the high permeability thin film (1) of the main magnetic pole and the perpendicular magnetic medium ( 5) Recording is performed by interaction with. (7) is a head support stand.

-Again. During playback, the cari-2 = A reproduction current flows through the loop (2), which is detected and utilized.

Now, in these cases, the magnetization reversal of the main pole occurs along the initial magnetization curve of the high magnetic permeability thin film (1).

This initial magnetization curve is important as a characteristic of the perpendicular magnetic head, and is closely related to the magnetic anisotropy of the thin film (1). The hysteresis curve (6) i8) and the initial magnetization curve (7) on the easy axis and hard axis of magnetization (hereinafter referred to as easy axis and hard axis) of the thin film (1) are shown on the second surface.
, an example of (9) is shown.

The magnetization process in the easy axis direction is due to domain wall movement, so the maximum permeability in the initial magnetization curve (7) is large, but the magnetization reversal speed is slow compared to the easy axis due to the rotation of 71 at high frequencies. much faster. Therefore, although the maximum permeability in the initial magnetization curve (9) is smaller than that in the easy axis.

The decrease in magnetic permeability at high frequencies is small.

On the other hand, the magnetic properties required of the high magnetic permeability thin film of the main pole are mainly a) good responsiveness to high-speed reversal of the && flux, and b) high reproduction sensitivity of point 02. For the reasons mentioned above, for a), the faster the magnetization reversal speed is, the better, which is advantageous for the difficult axis, and for b), the higher the magnetic permeability, the better, and the more advantageous it is for the easy axis. Because of these contradictory properties, it is impossible to use either the hard axis or the easy axis independently, and the magnetic properties of the hard axis and the easy axis coexist. By making it so-called isotropic, 1. It is said that the idea is to use it in a state where the regenerative sensation is heightened.

Figure 3 shows the isotropic hysteresis curve i (10) and its initial magnetization curve 1) (11).

Conventionally, in order to obtain the characteristics shown in Figure 3), a high magnetic permeability thin film made by sputtering, vapor deposition, plating, etc. was annealed in a rotating magnetic field to make it isotropic [7]. was.

However, with this method, the magnetic properties of the thin film sensitively respond to changes in the environment during the creation of the high magnetic permeability thin film and change slightly, so even if annealing is performed in a 9-rotation magnetic field, the magnetic properties of the thin film obtained are uneven. Reproducibility was poor.

Also, the annealing temperature differs depending on the high permeability material, but it is 30
Heating and cooling took time because it was necessary to raise the temperature to about 0 to 1100°C.

The present inventor focused on solving these problems.When a magnetic field is applied perpendicularly to the thin film during the formation of an elevated magnetic permeability thin film, the magnetic properties of the formed high magnetic permeability thin film can be easily equalized. I found the direction. The cause of this is not yet well understood, but by applying a perpendicular magnetic field during film formation.

Although the easy axis of the high magnetic permeability thin film tries to grow in a form close to perpendicular to the surface of the substrate, that is, the head support, the perpendicular magnetization condition H is ≦4TIl-MS (HK is the uniaxial magnetic difference in the perpendicular direction). Since the directional energy 1M9 does not satisfy the saturation magnetization), the grown film cannot have an easy axis in the direction perpendicular to the substrate.

As a result, the direction of magnetic anisotropy becomes random depending on the size of each crystal grain, and as a result, it is presumed that the grown film becomes isotropic.

−r−□− Nine embodiments of the present invention will be described below.

<Example 1> As shown in Fig. 4 (a), (b), tc+, the base &
Directly below (13), place a magnet (14) with the magnetization axis in the direction of the base (N), F'lr', t&,
The magnetic field lines were distributed as shown in FIG. 4(c).

FIG. 5 shows an example of the hysteresis curve of a permalloy film (78×Ni, 22×Fe) obtained by high-frequency sputtering using this substrate holder.

<Example 2> (13) is placed around the substrate holder (12) using a magnet.Also, as shown in Fig. 6(c), the substrate holder (12) is placed so that the film forming surface is at the top and bottom height. Yoke of magnetic permeability material (1
By arranging them so that they are between σ4, the lines of magnetic force (15) on the surface of the substrate can be uniformly directed perpendicular to the surface of the substrate. FIG. 7 shows an example of the hysteresis curve of a permalloy film (-6-78% N'l, 22% Fe) obtained by high-frequency sputtering using this substrate holder.

It was confirmed that the hysteresis curves of both the permalloy crotches produced in Example 1 and Example 2 did not change even when the magnetic field was rotated in the in-plane direction in an H-H) laser. As a result, it is considered that there is no magnetic anisotropy in the two in-plane directions and the material is isotropic. As described above, according to the present invention, a high magnetic permeability thin film that is isodirectional and has excellent magnetic properties can be easily produced with good reproducibility.

However, in this embodiment, the size, polarity, and shape of the magnets (14) (14') and the material and shape of the yoke plates (17) (17'), which are made of high magnetic permeability materials, are determined according to the necessity of high magnetic permeability thin films. The present invention is not limited to this embodiment as long as the lines of magnetic force (15) are uniformly oriented in a direction perpendicular to the film surface in the portion where the film is formed.

Although the high frequency sputtering method was used as the film forming method in this example, other vapor deposition methods, ion plate deposition methods,
A similar effect can be obtained by using a method such as plating. That is, the present invention regarding the film forming method is limited to this embodiment.
'l No.

[Brief explanation of the drawing]

FIG. 1 shows an example of a typical vertical head. FIG. 2 shows typical hysteresis curves and initial magnetization curves on the easy axis and difficult axis. FIG. 3 shows a hysteresis curve and an initial magnetization curve in the case of 9 isotropy with no magnetic anisotropy. FIG. 4 shows Embodiment 1 of the present invention, and (,) is a front view. fbl is a cross-sectional view, (C) is a distribution of magnetic lines of force, and Fig. 5 is a high magnetic permeability 4! , is an example of a hysteresis curve of a thin film. FIG. 6 shows a second embodiment of the present invention, and fa) is a front view. (bl is a cross-sectional view, (C) is the distribution of one magnetic field line, 41
Figure 7 shows an example of the hysteresis curve of the obtained high magnetic permeability thin film. (1): Main magnetic pole (2): Auxiliary magnetic pole (3): Coil (
4): Base film (5): Magnetic layer (6): Easy axis hysteresis curve (7): Easy axis initial magnetization curve (
8): Hysteresis curve of difficult axis (9): Initial magnetization curve of difficult axis (10): Hysteresis curve in isotropy (11)
: Initial magnetization curve in isotropy (12) : Substrate holder (14) (14: Magnet (15) : Lines of magnetic force (
17) (17: Yoke plate made of high magnetic permeability material Patent applicant: Nichiden Anelva Corporation

Claims (3)

[Claims] (1) When forming the main magnetic pole of a perpendicular magnetic recording head in the form of a thin film on the surface of the head support using sputtering, vapor deposition, plating, etc., lines of magnetic force are applied perpendicularly to the surface of the head support. By doing. A method for producing a main pole of a perpendicular magnetic recording head, characterized by obtaining a thin film having homomagnetic magnetic properties. (2) The method for producing a main pole of a perpendicular magnetic recording head according to item 1, characterized in that a magnet is used along the back surface of the head support. (3) The method for producing a main pole of a perpendicular magnetic recording head according to item 1, characterized in that the head support is disposed within a magnetic circuit using a magnet and a yoke plate made of a high magnetic permeability material.