JP2969361B2 - Method of manufacturing magnetic disk substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a method of manufacturing a magnetic disk substrate in a process of manufacturing a magnetic disk as a storage medium of a magnetic disk device which is an external storage device of a computer system, for example. To produce a high-quality magnetic disk with the same magnetic anisotropy that improves magnetic recording / reproducing characteristics from the inner peripheral portion to the outer peripheral portion of a magnetic disk manufactured by applying a magnetic coating to the magnetic disk; The purpose of this study is to manufacture a magnetic disk with a magnetic head that improves the buoyancy of the magnetic head at the position where the magnetic head makes contact start / stop (hereinafter referred to as CSS) on the disk. When pressing a polishing member against a flat surface to form a fine groove in the circumferential direction,
In order to prevent the processing state of the groove from being different due to a difference in peripheral speed between an inner peripheral portion and an outer peripheral portion of the magnetic disk substrate, the polishing member that presses from the inner peripheral portion to the outer peripheral portion of the magnetic disk substrate, A magnetic disk substrate manufacturing method characterized in that the magnetic disk substrate is divided into a plurality of polishing members having coarse abrasive particles toward the inner peripheral side and dense abrasive particles toward the outer peripheral side. .

[Industrial applications]

The present invention relates to a method of manufacturing a magnetic disk substrate in a process of manufacturing a magnetic disk as a storage medium of a magnetic disk device which is an external storage device of a computer system, for example.

[Conventional technology]

Conventionally, a method of imparting magnetic anisotropy for improving magnetic recording / reproducing characteristics to a magnetic film formed on a magnetic disk substrate in which a coating such as nickel and phosphorus is applied to the surface of an aluminum alloy disk substrate is as follows. I'm going like that.

That is, the magnetic disk substrate is chemically etched or, as shown in FIG. 3, a polishing member 2 such as a polishing tape is placed on the entire surface of the rotating magnetic disk substrate 1 in the radial direction. By pressing from both sides of the surface, fine grooves are formed in the circumferential direction. 3 is a pressing roller for pressing the polishing member 2 against the magnetic disk substrate 1, 4 is a support shaft of the pressing roller 3, and 7 is a magnetic disk substrate 1 of the pressing roller 3.
Is a pressure roller for applying a pressing force to the roller.

By forming fine grooves in the circumferential direction on the magnetic disk substrate 1 as described above, when a magnetic film is formed on the grooves, magnetic particles are arranged along the grooves to provide magnetic anisotropy. Magnetic recording / reproducing characteristics can be improved.

[Problems to be solved by the invention]

However, when a fine groove is formed in the circumferential direction by pressing the entire surface of the polishing member 2 against the entire surface of the magnetic disk substrate 1 and rotating the magnetic disk substrate 1 as in the related art, The inner peripheral side has a lower peripheral speed, the outer peripheral side has a higher peripheral speed, the inner peripheral side of the magnetic disk substrate 1 having a lower peripheral speed has finer grooves, and the outer peripheral side of the magnetic disk substrate 1 having a higher peripheral speed has Rough grooves are formed on the inner peripheral side, and such a difference in workability results in a difference in magnetic anisotropy and a difference in magnetic recording / reproducing characteristics.

Further, if a certain area of the magnetic disk substrate is adjusted to a desired condition, distortion of the other part due to processing increases, and that part causes a magnetic recording / reproducing error after the completion of the magnetic disk.

As described above, according to the conventional method, it is very difficult to produce a magnetic disk having good magnetic characteristics over the entire surface of the magnetic disk, that is, having few errors in magnetic recording and reproduction. Also,
Even if it can be done, the manufacturing conditions are severely restricted.

The present invention has been made in order to solve such a conventional problem, and has been developed in such a manner that a magnetic film is formed on a surface of a magnetic disk substrate by applying a magnetic film from an inner peripheral portion to an outer peripheral portion of the magnetic disk. To manufacture high-quality magnetic disks with the same magnetic anisotropy that improves the recording / reproducing characteristics, and to improve the floating characteristics of the magnetic head at the position where the magnetic head performs CSS on the magnetic disk. Is intended to be manufactured.

[Means for solving the problem]

SUMMARY OF THE INVENTION The present invention provides a
As shown in FIG. 4 and FIG. 4, when the polishing member 2 is pressed against the plane 1a of the rotating magnetic disk substrate 1 to form fine grooves in the circumferential direction, the inner circumference of the magnetic disk substrate 1 is formed. In order to prevent the processing state of the groove from being different due to a difference in peripheral speed between the portion and the outer peripheral portion, the polishing member 2 pressed against the outer peripheral portion from the inner peripheral portion of the magnetic disk substrate 1 A method for manufacturing a magnetic disk substrate, characterized by being divided into a plurality of polishing members 2 ₁ , 2 ₂ , 2 ₃ having coarse abrasive particles toward the inner peripheral side and dense abrasive particles toward the outer peripheral side. It was done.

[Action]

According to the present invention, that is, when the polishing member 2 pressed from the inner peripheral portion to the outer peripheral portion of the magnetic disk substrate 1 is divided into a plurality of polishing members 2 ₁ , 2 ₂ , and 2 ₃ having different abrasive particles, A high quality magnetic disk having the same magnetic anisotropy can be manufactured from the inner circumference to the outer circumference of the magnetic disk manufactured by applying a magnetic coating on the surface of the manufactured magnetic disk substrate 1. .

〔Example〕

Hereinafter, an embodiment of a method of manufacturing a magnetic disk substrate according to the present invention will be described in detail with reference to FIGS.

FIG. 1 is a schematic perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view of a pressing roller portion for pressing a polishing member against a magnetic disk substrate in the embodiment of the present invention. This is a magnetic disk substrate having a surface coated with a coating of nickel, phosphorus or the like, and is rotatably driven by rotation driving means (not shown). Numeral 2 denotes a polishing member such as a polishing tape for pressing the flat surface 1a of the magnetic disk substrate 1 to form fine grooves in the circumferential direction. In this embodiment, fine particles of alumina are applied to a polyester resin tape with a binder. It is formed by application through a hole.

In order to prevent the processing state of the fine groove from being different due to a difference in peripheral speed between the inner peripheral portion and the outer peripheral portion of the magnetic disk substrate 1, the polishing member 2 pressed from the inner peripheral portion to the outer peripheral portion is required. The polishing particles are divided into a plurality of polishing members 2 ₁ , 2 ₂ , 2 ₃ different from each other.

3 ₁ , 3 ₂ , 3 ₃ are the tape-like polishing members 2 ₁ , 2 ₂ ,
2 ₃ by a pressing roller, at least the outer peripheral portion for pressing the plane 1a of the magnetic disk substrate 1 is made of an elastic material, and the second
As shown, the support shaft 4 _1, 4 _2, 4 ₃ the support shaft 5 _1, 5 _2, 5 ₃ are rotatably mounted through these support shafts 4 _1, 4 _2, 4 ₃ Are connected by a universal joint 6. 7 ₁ , 7 ₂ , 7 ₃
Is a pressing roller which is a pressing member for applying a force for pressing the pressing rollers 3 ₁ , 3 ₂ , 3 ₃ against the magnetic disk substrate 1, and the support shaft of these pressing rollers is pressed by a spring or the like. It is pressed by the member 8 _1, 8 _2, 8 _3.

Said tape-like polishing member 2 _1, 2 _2, 2 ₃ of both ends in the core 9 _1, 9 ₂ is wound into a roll, the winding in Either this embodiment of the core 9 _1, 9 ₂ core 9 ₂ is adapted to be driven winding is a winding side.

When a polishing member of the same type is pressed against a rotating magnetic disk substrate as in the conventional example, a dense groove is formed in the inner peripheral portion of the magnetic disk substrate having a low peripheral speed, and the outer peripheral portion having a high peripheral speed is formed. since the coarse grooves are formed, the plurality of divided the polishing member 2 _1, 2 _2, 2 _3, coarse abrasive particles of the polishing member 2 ₁ is pressed against the inner peripheral portion, toward the sequentially outer peripheral portion When the abrasive particles are dense, uniform grooves are formed in the entire magnetic disk substrate 1.

Incidentally, the polishing member 2 _1, 2 _2, 2 ₃ as described above, so that processing the circumferential fine grooves on both sides thereof is pressed from both sides of the magnetic disk substrate 1.

When a magnetic film is applied to a magnetic disk substrate manufactured as in the embodiment described below by, for example, a well-known sputtering device, magnetic particles are aligned along fine grooves formed in a magnetic circumferential direction. With magnetic anisotropy, magnetic recording / reproducing characteristics can be improved.

[Effects of the Invention] As described below, the present invention provides a method for forming a fine groove in a circumferential direction by pressing a polishing member against a plane of a rotating magnetic disk substrate. In order to prevent the processing state of the groove from being different due to a difference in peripheral speed between the peripheral portion and the outer peripheral portion, a polishing member pressed from the inner peripheral portion to the outer peripheral portion is divided into a plurality of polishing members having different abrasive particles. Therefore, a high quality magnetic disk having the same magnetic anisotropy from the inner peripheral portion to the outer peripheral portion of the magnetic disk manufactured by applying a magnetic coating on the surface of the magnetic disk substrate manufactured in this manner. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an embodiment of the present invention, FIG. 2 is a sectional view of a pressing roller portion for pressing a polishing member, and FIG. 3 is a schematic perspective view of a conventional example. 1 ...... magnetic disk substrate 1a ...... plane 2 ...... polishing member 2 _1, 2 _2, 2 ₃ ...... polishing member 3 _1, 3 _2, 3 ₃ ...... pressing roller 4 ...... shaft 4 _1, 4 _2, 4 ₃ … Support shaft 5 ₁ , 5 ₂ , 5 ₃ … Bearing 6… Universal joint 7 ₁ , 7 ₂ , 7 ₃ … Pressure roller 8 ₁ , 8 ₂ , 8 ₃ … Press member 9 ₁ , 9 ₂ ... core

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/84 G11B 5/82

Claims (1)

(57) [Claims] When a polishing member (2) is pressed against a plane (1a) of a rotating magnetic disk substrate (1) to form fine grooves in a circumferential direction, the magnetic disk substrate (1) is formed. The polishing member (2) pressed against the outer peripheral portion from the inner peripheral portion of the magnetic disk substrate (1) so that the processing state of the groove does not differ due to the difference in the peripheral speed between the inner peripheral portion and the outer peripheral portion. Is divided into a plurality of polishing members (2 ₁ , 2 ₂ , 2 ₃ ) having coarse abrasive particles toward the inner periphery of the magnetic disk substrate (1) and dense abrasive particles toward the outer periphery. A method for manufacturing a magnetic disk substrate.