JPH0281323A - Production of magnetic disk for rotary encoder - Google Patents

Abstract

PURPOSE:To inexpensively produce the title disk having excellent workability and temp. characteristic by arranging plural discoid substrates on one side between targets with the side surfaces orthogonal to the target surface, and conducting sputtering vapor deposition while rotating the substrates. CONSTITUTION:Plural discoid substrates 2 made of a material having excellent workability such as aluminum are freely rotatably arranged by the space between a couple of opposed targets 3 and 3 with the side surfaces orthogonal to the surfaces of the targets 3 and 3. A lamp heater 9 for heating the substrate 2 is provided on the opposite side of the substrate 2 to the targets 3 and 3. The whole is evacuated by a vacuum pump to form the atmosphere of an electric discharge gas 8, an electric field 7 is generated between the targets 3 and 3 in direction of the arrow, and sputtering vapor deposition can be conducted. Since an inexpensive material having excellent workability can be selected for the substrate 2, the total cost can be reduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a magnetic disk for a rotary encoder, and in particular, a method for manufacturing a magnetic disk for a rotary encoder in which a magnetic thin film is formed on a disk-shaped substrate by a sputtering deposition method. It is related to.

[Prior art and problems to be solved] Conventional magnetic disks for rotary encoders are manufactured by sintering magnetic powder into a disk shape or by processing a magnetic alloy into a disk shape. The whole is made of a magnetic material, and as shown in FIG.
3 is known.

However, since magnetic materials are generally expensive, hard and difficult to process, the magnetic disk 21 made entirely of magnetic material is expensive and difficult to manufacture. The problem was that it was not suitable for mass production.

On the other hand, a disk-shaped substrate 22 is formed of a material that is easy to process, such as aluminum, and magnetic powder containing rare earth elements such as samarium cobalt and neodymium as a main component is applied to the disk-shaped substrate 22 with a resin binder. The magnetic layer #424 mixed in the magnetic paint 24 is coated to form the magnetic disk 21, and the side surface or surface periphery of the magnetic disk 21 coated with the magnetic paint 24 is coated with the magnetic layer #424 as shown in FIG. It is known that magnetic patterns 23 are formed by magnetizing at predetermined intervals.

As described above, the magnetic paint 24 is applied to the surface of the disk-shaped substrate 22.
The magnetic disk 21 coated with magnetic powder has the advantage that it is cheaper and has better workability than one made entirely of magnetic material. The problem is that the magnetic layer formed from the magnetic paint 24 is sensitive to high temperatures and has poor temperature characteristics.

In order to solve each of the above-mentioned problems, we focused on a method of providing a magnetic thin film of ferromagnetic material on the surface of a disk-shaped substrate by sputtering deposition.

The sputtering vapor deposition method has the advantage that the adhesion between the substrate and the magnetic 7ml film is large, and that the alloy of ferromagnetic materials can be deposited on the substrate without significantly changing the alloy composition. The present inventors have investigated the magnetron sputtering method, which has excellent ion generation efficiency among the Subakling deposition methods, and have also investigated the most common flat plate type (Brehner type).

In the flat plate type magnetron sputtering method, the sixth
It is configured as shown in Figure (4) (bl) and Figure 6 (
al shows the effect when a non-magnetic material is used for the target 33, and FIG. 6 1bl shows the effect when a ferromagnetic material is used for the target 33.

First, in the case shown in FIG.
A magnet 34 whose S and N poles are spaced apart from each other by a predetermined distance so that the lines of magnetic force 35 form an arch on the upper surface side is arranged, and a magnet 34 is arranged such that an electric field 37 is formed perpendicularly from above to below the target 33. Then, in an atmosphere of a discharge gas 38 such as argon, electrons generated from the Kuget 33 are efficiently captured inside the magnetic field 36 indicated by the magnetic lines of force 35,
The generation efficiency of positive ions formed by ionizing the discharge gas 38 is improved by these electrons, and a large amount of positive ions collide with the target 33 for sputtering deposition.

On the other hand, in the case where a ferromagnetic material is used as the target 33' shown in FIG. Since the magnetic field 36 is not formed in the target 33, the electrons generated from the target 33 as described above cannot be captured, resulting in poor generation efficiency of the magnetic thin film by sputtering deposition, and the electrons reflected by the target 33 are not formed on the substrate. This method could not be applied to the method of manufacturing a magnetic disk for a rotary encoder because the magnetic thin film collided with the magnetic thin film and the magnetic thin film was damaged.

The present invention solves the problems of the conventional disks as described above, and has superior processability, better temperature characteristics, and can be manufactured at a lower cost than when the entire magnetic disk is made of magnetic material. The present invention aims to provide a method for manufacturing a magnetic disk for a rotary encoder that can be mass-produced by improving the production efficiency of a magnetic thin film by sputtering deposition using a ferromagnetic material as a target.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a facing target type sputtering method in which a magnetic field and an electric field are simultaneously applied between a pair of targets made of ferromagnetic materials that are disposed facing each other at a predetermined interval to perform sputtering deposition. A plurality of disc-shaped substrates are disposed on the sides between the targets of the apparatus so that the side surfaces thereof are perpendicular to the target surface, and
The method includes means for performing sputtering deposition while rotating the plurality of disc-shaped substrates.

[Effect]

By employing the above means, the present invention can efficiently form a magnetic thin film of a ferromagnetic material on at least the side surfaces of a plurality of disk-shaped substrates.

〔Example〕

Embodiments of the present invention shown in the drawings will be described below.

FIG. 1 (b) is a schematic explanatory diagram of a facing target type sputtering device used in the method of manufacturing a magnetic disk for a rotary encoder according to the present invention. FeCrCo
A pair of targets 3.3 made of a ferromagnetic material such as an alloy are arranged facing each other at a predetermined interval, and a magnetic field 6 having lines of magnetic force 5 perpendicular to the surfaces of the pair of targets 3.3 facing each other is formed. A magnet 4.4 is arranged on the opposite side of the facing surface of each target 3.3, and a disc-shaped magnet 4.4 is arranged on the side between the targets 3.3 using a material with good workability such as aluminum. Disk-shaped substrate 2 molded into
A plurality of sheets (15 sheets in the drawing) are rotatably arranged with their side surfaces perpendicular to the surface of the target 3.3, and the disk-like substrate 2 is placed on the opposite side of the target 3.3. A lamp heater 9 for heating No. 2 is arranged,
Further, the entire structure is depressurized by a vacuum pump (not shown) to form a discharge gas 8 atmosphere, and an electric field 7 is formed between the pair of targets 3 and 3 in the direction of the arrow to enable sputtering deposition. .

The 15 disk-shaped substrates 2 are arranged at predetermined intervals so as to form a cylindrical rod.

Further, the disk-shaped substrate 2 may be made of a non-magnetic material such as aluminum or a magnetic material, and a material that is inexpensive and easy to process can be appropriately selected.

Next, the operation of the above will be explained.

In the facing target type sputtering apparatus configured as described above, the inside of the apparatus is brought into a predetermined reduced pressure state by a vacuum pump (not shown), a discharge gas 8 atmosphere is created, and a magnetic field 6 and an electric field 7 are applied between the targets 3 and 3. When set to work simultaneously and start sputtering, first, electrons 10 are emitted from the target 3.3, and these electrons 10 are efficiently captured between the targets 3.3 by the IF field 6 and the electric field 7. At the same time, the target 3.3 reciprocates while making a cycloidal movement around the magnetic field lines 5, ionizing the discharge gas 8 and producing many positive ions, which are then transferred to the target 3.3. The target 3.3 made of a ferromagnetic material collides with the target 3.3 to produce thin film-forming atoms.

On the other hand, on the side between the targets 3.3, 15 disk-shaped substrates 2 are rotating with their side surfaces perpendicular to the surface of the targets 3.3, and are separated from the pair of targets 3.3. The ejected atoms forming a thin film made of ferromagnetic material adhere to the side surfaces and peripheral edges of the surfaces of the 15 disk-shaped substrates 2, and as shown in the second rili, a magnetic thin film 12 made of ferromagnetic material is formed on the disk-shaped substrate 2. is formed, and the magnetic disk 1 is manufactured.

Then, magnetic thin #12 of the magnetic disk l obtained above
As shown in FIG. 3, a magnetic pattern 11 having a predetermined magnetization pitch can be formed and used as a rotary encoder.

The one shown in FIG. 3 (tal) above is one in which the magnetic thin film 12 on both the side surface and the peripheral edge of the magnetic disk l is magnetized, and the one shown in FIG. Only the thin film 12 is magnetized, as shown in FIG.
The one shown in FIG. 1 is one in which only the magnetic thin film 12 at the peripheral edge of the surface of the magnetic disk I is magnetized, and any of them can be employed in the method of the present invention.

By using the above-mentioned method, the present invention can select an appropriate material that is inexpensive and has good workability for the disk-shaped substrate 2, thereby reducing the overall cost, and also has good temperature characteristics since no resin binder is used. In addition, compared to flat plate sputtering, the efficiency of sputtering deposition can be improved, and magnetic thin films can be formed on a plurality of disc-shaped substrates simultaneously, thereby improving mass productivity.

〔Effect of the invention〕

By employing the above-mentioned means, the present invention can improve the efficiency of sputtering deposition compared to flat plate sputtering, and can simultaneously form magnetic thin films on a plurality of disk-shaped substrates, resulting in excellent mass productivity of magnetic disks. , it has excellent effects such as being able to select an appropriate material that is inexpensive and has good processability for the disk-shaped substrate, reducing the overall cost, and obtaining a magnetic disk with good temperature characteristics because it does not use a resin binder. It is something.

[Brief explanation of the drawing]

Fig. 1fa) (bl shows an opposed target type sputtering device used in the method of manufacturing a magnetic disk for a rotary encoder according to the present invention, Fig. 1ta+ is a schematic explanatory diagram, and Fig. 1(b) is a FIG. 2 is a perspective view of a magnetic disk manufactured according to the present invention, and FIG. 3 (δ) fbl and fcl represent different types of the magnetic disk shown in FIG. Figure 4 is a perspective view of a magnetic disk magnetized with a magnetic pattern of
5 is a perspective view of a magnetic disk manufactured by one conventional manufacturing method and magnetized with a different type of magnetic pattern, and FIG. 5+a+ (b) is a perspective view of a magnetic disk manufactured by another conventional manufacturing method. A perspective view of a magnetic disk magnetized with a type of magnetic pattern, Figure 6 tal
fbl shows an explanatory diagram of the action of a conventional sputtering device, Fig. 6 fa) is an explanatory diagram showing the action when a non-magnetic material is used as the target, and Fig. 6 fbl shows the action when a magnetic material is used as the target. FIG. 21... Magnetic disk 22... Disc-shaped substrate 33... Target 34... Magnet 35... Lines of magnetic force 36... Magnetic field 7.37... Electric field 8.38... Discharge gas 9... Lamp heater 10... Electron 11.23... Magnetic pattern 12...Magnetic thin film 24...Magnetic paint Fig. 2 Fig. 3 (a) l N aJ Tomi ear cover Fig. 3 (b) Row 3 Fig. 3 (C) Fig. 4 Fig. 4 Figure 5 Figure 5 (b) Figure 6 (0) 6, Figure 6 (b) Takayoshi

Claims (1)

[Claims] (1) Sides between the targets of a facing target sputtering device that performs sputtering deposition by applying a magnetic field and an electric field simultaneously between a pair of targets made of ferromagnetic materials that are arranged facing each other at a predetermined interval. A method for manufacturing a magnetic disk for a rotary encoder, characterized in that a plurality of disk-shaped substrates are arranged so that their side surfaces are perpendicular to the target surface, and sputtering deposition is performed while rotating the plurality of disk-shaped substrates. .