JPS58130440A - Magnetic disc - Google Patents

Abstract

PURPOSE:To improve orientability in a vertical direction by using a soft magnetic material having high magnetic permeability as a base plate. CONSTITUTION:A magnetic alloy plate having high magnetic permeability such as ''Permalloy '' is worked to a disc shape and is annealed to relieve mechanical strains and magnetic strains; thereafter, the surface of the disc is finished to a specular surface by polishing. Magnetic films 602, 603 of Co-Cr, etc. are formed by sputtering on both surfaces of a base plate 601. The base plate may be formed into the type wherein the soft magnetic alloy plates having high magnetic permeability are laminated on both surfaces of an aluminum alloy plate. It is also possible to provide an amorphous non-magnetic thin film layer between the soft magnetic material having high magnetic permeability and the magnetic film for recording.

Description

[Detailed Description of the Invention] The invention is directed to a magnetic ball distribution medium, in particular, to a magnetic distribution medium, in particular, to a magnetic component perpendicular to the surface of the medium, which allows a high-magnetization record meeting to be carried out.
Concerning the structure of the medium.

When increasing the temperature on the e-recording medium, the magnetization on the medium becomes stronger in the direction of the thickness of the medium, that is, in the direction perpendicular to the surface of the medium. Furthermore, when the recording density is increased, the appearance on the medium includes a large number of components in the vertical direction. Therefore, 8ef#,
In some cases, it is desirable to apply the recording magnetic field perpendicularly to the medium surface in advance, and also to take a structure in which the residual recording magnetization on the medium port is also perpendicular to the medium surface. is promising.

In general, the technology of recording and reproducing in the direction of force perpendicular to the medium surface (opposing the thickness of the medium) is called perpendicular magnetization@e-ring. ”
(May 26, 1972).

FIG. 1 shows the principle of magnetic recording in the direction perpendicular to the medium surface. In the figure, on the surface of a substrate 101, there is an S thin film layer 102 that serves as a frost recording medium. The magnetic pole 103 of the S-air head facing the medium 102 concentrates the recording magnetic field generated by the coil on the tip of the magnetic pole 106, near the tip of the magnetic pole 106, which faces the medium 102, thereby completely magnetizing the medium and recording. At this time, the recording magnetic field applied to the medium is applied to the magnetic pole 10 as shown by the broken arrow 106.
3, perpendicular to the plane of the medium X102, that is, facing in the thickness direction of the medium 102. The medium is perpendicularly magnetized by such a perpendicular recording magnetic field. Generally, when a thin film magnetic medium is magnetized in the direction perpendicular to the medium surface (arrow 104), the recording magnetization is reduced by the demagnetizing field 105 generated by the medium itself.However, the reversal interval of the S distribution is approximately equivalent to the thickness of the medium. When
The desensitizing effect becomes negligible. Figure 1: Magnetic pole 10
In the medium facing section No. 3, the magnetic field at the end is indicated by the arrow 107.
The component in the direction parallel to the medium surface becomes sharper. Therefore, when the medium 102 is moved to the magnetic pole 103 to record all data, the medium is magnetized by the magnetic field at the rear end of the S pole 103, and the component parallel to the medium surface is large as described above. This results in a long magnetization recording. Figure 2 shows magnetic 7
By providing the high-encounter rate soft magnetic thin film layer 203 between the recording medium 202 and the substrate 201, the recording magnetic field generated by the magnetic field 103 is made perpendicular to the medium surface even at the rear end of the magnetic pole tip, and the recording magnetic field is made to be S. The tub is designed so that the demagnetizing effect due to its own repulsion field does not occur even in a region where the reversal interval is relatively large relative to the thickness of the medium. In FIG. 2, the F recording magnetic field becomes perpendicular to the medium near the point where the magnetic pole 103 faces the medium 202, as indicated by the broken line. FIG. 3 shows that when the full magnetic field is applied as shown in FIG. 2 and the recording magnetic field is reversed while moving the medium 202 relative to the magnetic pole 103, the recording on the medium becomes n'fC6B and the direction of the magnetic field generated by this n. It is shown in P'. The arrow indicates the magnetization within the medium 202, and the broken line indicates the direction of the magnetic field, ie, the magnetic flux flow t. The magnetic field is created in a closed loop by adjacent magnetized comrades with different directions. In particular, due to the presence of high permeability m 20 s, all magnetization within the medium is oriented perpendicular to the medium surface, and the magnetization is high. j The magnetic field within the magnetic layer 203 has the same rotation in the direction parallel to the magnetic layer.

Conventionally, a 'fC magnetic disk using a high-density outsourced recording medium as shown in FIG.
The substrate is made by processing aluminum alloy into a disk shape and polishing the surface to give it a mirror finish. On this aluminum alloy substrate, two thin films of 2o2 and 203 are vaporized or sputtered in vacuum.
01 is an example of a vacuum system in which the first two magnetic films are completely continuously formed by sputtering. 402 is the front stage vacuum chamber, where magazine 4 is mounted with a large number of aluminum disks after surface polishing.
Insert 06 and apply vacuum. Dis 4 from previous Me Makazin
Sequentially extracting 10i one by one Fθ-N1 sputtering chamber 40
Send to 3. F e −N i toward the upper side of the frozen disk
target 408 all sputtered Fθ-N1 thin 11
Form into 1. Next, a similar F p -Ni thin fflik is formed on the upper surface of the disk using a target 409 . Fθ-NiO high permeability magnetic thin film is formed on both sides of the disc 412'k Co-C! r sputtering chamber 404
Co-Cr target 413 in the same way as in the front chamber.
and 414, a Co-Or magnetic film is sputtered on both sides. The disk on which all layers of sputter have been formed is stored in a disk mount magazine 407, which is sent to a disk take-out chamber 405 at the final stage. Here, the front and rear chambers are separated from the sputtering chamber by vacuum walls 416 and 417.

Furthermore, the sputtering chambers 403 and 404 are shielded by a wall 415 to prevent the effects of sputtering in other chambers from being influenced during each sputtering operation. That is, baking soda is used to prevent interference due to sputtering conditions or contamination of other components.The fourth design 401 not only requires a large scale, but also requires a large number of steps and has a low throughput.

Even in the case of film formation by passion, the structure is almost similar, and due to the incendiary nature of anisotropic film formation, which will be described later), in reality, it has to be larger than the sputtering method. .

Now, in order to make it easier for the magnetization in a magnetic medium to be oriented in a direction perpendicular to the surface of the medium, it is desirable that the magnetic domains of the medium itself be aligned in the direction of force perpendicular to the surface of the medium.

In other words, n is desirably selected so that the direction of crystal orientation of the magnetic medium is perpendicular to the entire surface of the medium along the axis of easy magnetization of the crystal. In fact, alloys containing rare earth elements such as co-Cr,
By sputtering or vapor deposition, it has been possible to achieve orientation with a force perpendicular to the surface of about 1.

In general, it is known that the crystal growth of a film greatly depends on the surface characteristics of the substrate on which the protective film is formed, and is greatly influenced by the shadow of the substrate surface. In fact, when the film is formed by C0-Cr or similar alloy B'4's-sputtering, the crystal anisotropy of the film varies greatly depending on the substrate. Figure 5 shows
71: The crystal orientation state of the Co-Cr alloy magnetic chain is
This is a graph measured by line diffraction, with the horizontal axis representing the angle and the vertical +
This is an output luxury for l11. 505 is a square corner on the X-ray diffraction graph when the axis of easy magnetization is perpendicular to the medium surface. The narrower the distribution of the curve near the angle 505 and the larger the peak value, the more aligned the orientation of section a is perpendicular to the medium surface. On the other hand, when the distribution near the corner 11i505-1-j is wide and the peak value is small, the orientation of the magnetic domains is uneven. Figure 5 501 shows the previous 1i7C! on the glass substrate! All foot measurement data are shown when an o-Or sensitive film is formed. 502 is formed by sputtering on a Fe-Ni alloy substrate, this is made into a high magnetic permeability sensitive film, and furthermore, C0 film is formed by sputtering on this. -0r alloy? This is measurement data when formed. It is clear that c formed on the Fe-Ni alloy film
The force orientation of the o-cr magnetic film is poor. That is, when a magnetic recording medium having the structure shown in FIG. 2 or 3 is manufactured as described above, the outer medium itself becomes smaller than when the magnetic recording medium has only one layer as shown in FIG. The magnetic anisotropy of the medium is inferior, and the effect of the high magnetic permeability sensitive film provided under the medium is substantially reduced.
Two.

The invention is suitable for high-density S-HC recorders for such conventional problems. It has a soft magnetic material with high magnetic permeability and is oriented in the direction of force perpendicular to one medium! The purpose is to provide a magnetic recording medium with excellent characteristics.

Figure 6 (Al is processed into a high magnetic permeability soft sensitive alloy plate such as permalloy into a whole disk forest, annealed to prevent mechanical distortion,
After removing the Nagi plane, the surface of the disk was polished and finished. Distortion removal by annealing or improvement of S gas percentage may be performed after polishing. The substrate (Al
On both sides of 2O2, the sputtered ic, Kt)Co
-Or, etc. (7) am M602.6037 is formed, and the entire magnetic disk is formed. Therefore, the substrate 60 in FIG. 6(B)
1 is the rock side part + 4 for the mechanical strength of the disc itself.
At the same time, the third layer 203 also serves as a 1ζ-high magnetic permeability sensitive film. Compared to the conventional disk manufacturing process shown in FIG. 4, it is clear that the sputtering process is reduced by approximately half, resulting in a significant improvement in system loop. In addition, there is no problem of interference caused by adjacent dissimilar materials or harmful spatter processes, which greatly simplifies the structure and process conditions of the mounting section, contributing to improved yields. Ring 7 diagram is another example. As shown in (C), thin high magnetic permeability S outer plates 702 are placed on both sides of an aluminum alloy plate 701 at the center. The above three boards are laminated by full pressure welding (D
) Laminating group like 8! Form wo. Process, polish, and remove distortion from the substrate in (D).

Then, a disk substrate (K) is formed. The three boards can be welded and laminated, or they can be laminated with adhesive. The thickness of the high magnetic permeability sensitive film 702 is
Depending on the thickness of the aluminum alloy '701, the difference in thermal expansion coefficient due to inversion is ignored. The substrate (Shu) can effectively achieve the same weight and mechanical strength as aluminum alloy.The entire recording magnetic film is coated on both sides of the substrate (lfl) in the same process as described above.
It will be a magnetic 7 disc. Similarly to FIG. 6, the substrate shown in FIG. 9-7 has a significantly shorter manufacturing process than the conventional one, making it possible to provide a practical disk.

Seventh, as a result of forming the C0-0r alloy on different substrates by sputtering, there are some substrates other than the previous Mix'L glass substrate that have the same excellent distribution of eyes as the four glass plates.

When a C0-0r film is formed on a trowel formed with Sin or other films that are generally close to amorphous, the fifth
A U9 diffraction peak as steep as that of Co-0rPIA on the glass substrate shown in FIG. 501 was observed. Figure 5 150
6 indicates the range of angles in which an output of 50% or more with respect to the peak output is measured.
In the case of -0r film, it is about 0 degrees. Further, similar values were obtained for Co--Cr formed on a so-called polyimide substrate, and similar results were obtained for other polymeric materials when the entire Co--Cr film was formed. On the other hand, for the measurement data curve 502 of CCo-0r formed on the @fii'N1-Fθ permalloy alloy, the peak output is significantly lower than that of 501, and the output is more than 50% of the vibration output. The measured angle range is about 10 to 20 degrees. The same applies to the case where a permalloy film other than Ni-Fe based, for example, a permalloy film containing Crx-Mof is used as the base. Furthermore, it can be seen that when aluminum, other metals, and their alloys are used as substrates, the deterioration is the same or more than that. 1) The magnetic properties corresponding to the perpendicular magnetic properties of the magnetic film can be obtained from the results of measuring the magnetic anisotropy of the magnetic film.

From the above results, it is desirable that the entire substrate be made of a material that has a lattice size that is extremely different from the lattice of the crystal for the crystal of the material that forms the thin film.

Since the lattice constants of metals are close to each other, the growth of the magnetic film is likely to be influenced by the substrate metal.

On the other hand, when a magnetic film is made of an amorphous or part-7 material as a base plate, it grows without being influenced by the substrate, so it becomes possible to form a film with excellent magnetic anisotropy. In fact, the C0-Cr magnetic Ill formed on an amorphous material or a polymeric material has a film thickness of several thousand angstroms or more, as shown in Fig. 50.
It exhibits excellent NRC diffraction characteristics like 1.

Figure 8 shows the cross-sectional structure of the magnetomagnetic medium produced based on these data, in which a high permeability soft magnetic material 802 is formed on the substrate Aoi, and the soft magnetic material 802 is further On top is non-magnetic 11#803.

The non-magnetic region 803 is amorphous or close to amorphous η with the upper P
It is made of intestines or a polymeric material 701.

When 801 in FIG. 8 is constructed of a high magnetic permeability substrate as shown in FIG. 6, 802 is of course unnecessary. The nonmagnetic layer 503 is OVD
It can be easily formed by method, dipping, coating, etc.

Skewers formed by sputtering are also possible.

[Brief explanation of the drawing]

FIG. 1 shows the principle and mission of magnetic recording related to non-invention. FIGS. 2 and 3 show the effect of a high magnetic permeability substrate 1 provided under the recording medium on the output side, and FIG. 4 shows a blank for a mounting pot in which a two-layer ejectable film is continuously formed. FIG. 5 shows the crystal distribution characteristics of the recording medium by X-ray diffraction. Figure y46.7.8 shows the structure of the magnetic disk according to the present invention. 102.202.804・<ii Recording medium 203.60
1,702.802-...High permeability magnetic material 803...Non-magnetic film = 13-6Qs (Sun 193-

Claims (1)

[Scope of Claims] (1) A magnetic disk entirely made of a high magnetic permeability soft magnetic material and having a magnetic thin film layer for F weight formed entirely on the soft substrate (2) Two high magnetic permeability soft substrates Sandwich the aluminum alloy substrate between them and laminate, and the surface of the laminate substrate has magnetic properties for recording. ! ! A-disc with complete formation of the spindle layer. (3) Is there any hidden property between the high magnetic permeability soft sensitive material and the 8e recording magnetic thin film? 1. The 1iBi disk according to paragraphs 1 and 2 of the patent scope, in which the invention is difficult to overcome. (41) The magnetic disk according to claim 3, wherein the non-magnetic thin layer is an amorphous corpus luteum.