JPS61180932A - Cutting method of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium which excels in the magnetic characteristics and reliability by cutting a magnetic layer into a prescribed form with irradiation of a laser beam and then cutting the magnetic recording medium by a cutter in accordance with said prescribed form. CONSTITUTION:A laser beam L is absorbed by a magnetic layer 12 with high efficiency since the magnetic material of the layer 12 is colored. While the beam L passes through a substrate 11 which dose not absorb the beam L. therefore when the beam L is irradiated on the substrate 11 containing the layer 12, only the irradiated areas of the layer 12 are heated instantaneously up to a high temperature and evaporated. Thus a cutting groove 15 is formed. Then the layer 12 is cut along the groove 15 by a metallic cutter 17 and at the same time the width of a magnetic recording medium is controlled to the prescribed value. Thus the magnetic recording medium cut in such a way has no cracks produced to the layer 12 and has the smooth cut ends.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for cutting a magnetic recording medium such as a magnetic tape, and more particularly to a method for cutting a magnetic recording medium that does not cause cranking in the magnetic layer.

[Conventional technology]

In recent years, in the field of magnetic recording, there has been a trend towards higher density recording and shorter wavelength recording signals. Magnetic recording media have been proposed.

On the other hand, in response to the above-mentioned high-density recording, for example, Co-C
A magnetic recording medium, such as a so-called vapor-deposited tape, has been proposed in which a magnetic layer is formed by directly depositing a ferromagnetic metal material such as r-alloy on a non-magnetic substrate by vacuum deposition or sputtering.

These magnetic recording media are usually manufactured by forming a magnetic layer on a substrate, feeding the substrate into a cutting device, and cutting the substrate into a predetermined width using a cutter in the device.

By the way, in this cutting process, in the above-mentioned coating type magnetic recording media, the magnetic powder tends to become hard and the reeds tend to be highly filled, so this hard magnetic powder causes significant wear on the cutter and Unreasonable cutting force causes distortion in the magnetic layer, causing cracks and cooling at the cut end of the magnetic layer, causing magnetic powder to fall off and making the cut end uneven, deteriorating magnetic properties and reducing reliability. There was a problem that it resulted in a poor magnetic recording medium.

Furthermore, the above-mentioned problem is noticeable even in vapor-deposited magnetic recording media, and in particular, since the magnetic layer is formed only of a hard metal magnetic thin film, the canter wear is significant and this magnetic thin film can fall off. There was a problem.

[Problem to be Solved by the Invention 9] As mentioned above, in the conventional cutting method for magnetic recording media, cranks occur in the magnetic layer and the cut edges become uneven, resulting in poor magnetic properties and reliability. There was a problem with magnetic recording media.

Therefore, the present invention has been proposed in order to solve all of these problems, and it is possible to cut the mother layer so that the cutting edge is smooth without producing cranks. Therefore, it is an overall object of the present invention to provide a method for cutting a magnetic recording medium that can be used without worrying about magnetic properties or reliability.

[Ninth method to solve all problems]

In order to achieve all of these objects, the method for cutting a magnetic recording medium of the present invention is to provide a magnetic layer on a substrate, cut the entire magnetic layer into a predetermined shape by irradiating the entire magnetic recording medium with a laser beam, and then cut the entire magnetic layer into a predetermined shape. Along with the above magnetic recording media? The entire feature is that it is cut with a cutter.

[Effect]

Therefore, according to the present invention, the cutting process of the magnetic recording medium is divided into two steps. First, the magnetic layer is completely cut with a laser beam, and then the magnetic recording medium is cut with a cutter, so that the magnetic layer is instantly evaporated. A smooth cut is made without cranking, reducing wear and damage to the cutter and cutter.

〔Example〕

Hereinafter, a specific embodiment of a method for cutting a magnetic recording medium to which the present invention is applied will be described in detail according to the process sequence shown in FIGS. 2 to 6.

First, as shown in FIG. 2, a magnetic layer 12 is formed on a substrate 11 made of a nonmagnetic material such as polyethylene terephthalate.

The magnetic material and forming method for the magnetic N12 include γ-
Fe20. ferromagnetic oxide powders such as metals such as Fe, Co, ferromagnetic metal powders such as Fe-Co alloys, coating methods using resin binders such as all-vinyl chloride, or
, Co, Ni, and other metals.

Any number of methods may be used in which a ferromagnetic metal material such as -Ni alloy is directly deposited on the substrate 11 by a vacuum thin film forming technique such as vacuum evaporation or sputtering.

Next, as shown in FIG. 3, a laser beam, ilL', is applied to the substrate 11 on which the magnetic layer 12 is formed.
it: Irradiation is performed at predetermined intervals to cut only the magnetic layer 12.

Although not shown, the laser beam is emitted from a laser oscillation device S, passes through an optical system such as a prism or a mirror, and is focused and irradiated by a converging lens 14. CO is used as the oscillation source of this laser beam. High-power lasers such as gas lasers, argon gas lasers, and YAG lasers (indolium-aluminum garnet crystals) are used.The beam diameter of this laser beam is, for example, 100 μm.
Use only.

On the other hand, the laser beam is efficiently absorbed by the magnetic layer 12 because the magnetic material constituting the magnetic layer 12 is an envelope, and the substrate 11, which does not absorb laser beams of this wavelength, does not pass through. It ends up.

Therefore, the magnetic layer 12f! : When the formed substrate 11 is irradiated with a laser beam If, the magnetic layer 1 in the irradiated Ai portion
2 is instantaneously heated to a high temperature and evaporated, forming grooves 15 and cutting the magnetic layer 12.

In order to prevent the magnetic layer 12 from being rapidly heated by the laser beam irradiation, which would adversely affect the magnetic properties of the magnetic layer, the magnetic layer 12 was heated while blowing an inert gas onto the gold laser irradiation area. It is preferable to cut the

Further, since the heat generated by the laser beam irradiation is dissipated through the magnetic layer 12 having good thermal conductivity, the substrate 11 is not affected by deformation or the like due to this heat.

Finally, as shown in FIG. 4, the substrate 11' is cut along the kerf 15 with a cutter 17 made of metal or the like, and the width of the magnetic recording medium is regulated to a predetermined width.

The A7 magnetic recording medium cut in this way has a smooth cut edge without any cracks in the magnetic layer 12. Further, since the hard magnetic layer 12 is cut by a laser beam and the cutter only needs to cut the relatively soft substrate 11, wear of the cutter is reduced and its life is extended.

Next, an example of a cutting device for carrying out the present invention will be described with reference to FIG. 1.

This cutting device forms a magnetic layer on the substrate and cuts the magnetic tape.
a, Ta... It is a device that obtains all the laser beams, that is, a plurality of lenses 2, 2... are arranged in parallel at predetermined intervals to completely focus the laser beam on the mountain recording medium 1. , a plurality of cutters 4, 4, . . . are provided in front of the lenses 2, 2, . The magnetic recording medium 1 is moved in all eight directions at a predetermined speed while the magnetic recording medium 1 is irradiated with a laser beam, L... to cut the magnetic layer. By further cutting the magnetic recording medium 1 along the magnetic layer with the cutters 4, 4, . . . , magnetic chips la, la, . . . of a predetermined width can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, the method of cutting a magnetic recording medium is divided into two steps: first, the entire hard magnetic layer is cut with a laser beam, and then the width is regulated with a cutter, and the magnetic recording medium is cut. Therefore, this magnetic layer is not affected by the cutting force of the cutter, and the crank and magnetic powder do not fall off, resulting in a smooth cut. Therefore, we get n
The i-magnetic recording medium has superior magnetic properties and reliability.

However, since the hard magnetic layer is cut with a laser beam, wear on the cutter is reduced compared to conventional methods, and the life of the cutter is extended.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of an example of a cutting device for carrying out the present invention. FIGS. 2 to 4 show a magnetic recording medium cutting method according to the manufacturing process according to the present invention. 2 is a schematic cross-sectional view of a recording medium, FIG. 2 is a step of forming a magnetic layer, FIG. 3 is a step of cutting the magnetic layer with a laser beam, and FIG. 4 is a step of cutting the magnetic recording medium with a daca saw. 1...Magnetic recording medium 4.17...Cutter 11...Substrate 12...Magnetic layer

Claims (1)

[Claims] A magnetic recording medium having a magnetic layer provided on a substrate is irradiated with a laser beam to cut the magnetic layer into a predetermined shape, and then the magnetic recording medium is cut with a cutter along the shape. How to cut recording media.