JPH0916960A - Manufacturing device for information recording medium - Google Patents

Abstract

PURPOSE: To obtain the manufacturing device for the information recording medium which can manufacture the information recording medium having magnetic characteristics improved at low cost. CONSTITUTION: This manufacturing device for the information recording medium heats, fuses, and vaporizes ferromagnetic metal 9 in a crucible 8 arranged in a vacuum tank 1 and deposits the vaporized metal on the base 2 of the information recording medium. The opening part of the crusible 8 in the width direction corresponding to the width direction of the base 2 is divided into plural openings (vaporizing chamber 17) and the vapor flow of the ferromagnetic metal 9 passes through the respective openings and is made to adhere onto the base 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing an information recording medium such as a magnetic tape or a magnetic card, and in particular, a ferromagnetic metal is heated and melted to evaporate, and the evaporated metal is vapor-deposited on a substrate. The present invention relates to an apparatus for manufacturing an information recording medium that forms a recording layer.

[0002]

2. Description of the Related Art Generally, a magnetic layer of a metal thin film type magnetic tape such as a vapor deposition tape is produced by heating a ferromagnetic metal by electron beam irradiation in a crucible provided in a vacuum chamber and evaporating metal vapor to polyester or the like. It is adhered on a substrate made of a plastic film, and is formed to have a predetermined thickness.

Particularly in a mass-production manufacturing apparatus, a crucible having a width longer than the width of the substrate is used in order to form a magnetic layer on a wide substrate while minimizing the film thickness distribution in the width direction. Then, the ferromagnetic metal filled in the crucible is irradiated with an electron beam while scanning in the width direction to uniformly heat and evaporate the ferromagnetic metal.

[0004]

However, when the width of the evaporation source is widened by using such a wide crucible, for example, the vapor from one end portion of the crucible does not go to just above the crucible but the cosine law. As a result, a wide-angle wide-angle incident vapor is generated at each evaporation position in the width direction so as to go to the opposite end portion as well, so that many collision scatterings occur before the vapor reaches the substrate, and as a result, formation occurs. The in-plane anisotropy azimuth of the magnetic film is inclined obliquely from the tape longitudinal direction, and the magnetic anisotropy azimuth in the film in-plane rises from the film plane and the orientation of the film deteriorates. There is a problem that magnetic characteristics and electromagnetic conversion characteristics are deteriorated.

Another problem is that there is a distribution of magnetic characteristics and electromagnetic conversion characteristics in the film width direction of the original magnetic tape.

On the other hand, in general, a magnetic layer such as a vapor deposition tape is formed by an oblique incident vapor deposition method in order to obtain recording / reproducing characteristics suitable for an in-plane recording medium. In this oblique incident vapor deposition method,
The magnetic film is formed by utilizing only a very limited part of vapor component of the evaporated metal. As a result, the vapor deposition efficiency decreases,
There is a big problem that the production cost becomes high.

The present invention solves the problems relating to vapor flow scattering and vapor deposition efficiency in the above-mentioned prior art, and can manufacture an information recording medium having improved magnetic characteristics at low cost. The purpose is to provide.

[0008]

In order to achieve the above-mentioned object, the present invention heats and melts and evaporates a ferromagnetic metal in a crucible arranged in a vacuum chamber, and the evaporated metal is used as an information recording medium. In an apparatus for manufacturing an information recording medium which is vapor-deposited on a substrate, an opening in the width direction of the crucible corresponding to the width direction of the substrate is divided into a plurality of openings, and a vapor stream of a ferromagnetic metal passes through each opening, and It is characterized in that it is configured to be attached to.

In the above information recording medium manufacturing apparatus, the opening of the crucible is divided into a plurality of openings by a partition wall extending in the depth direction of the crucible.

[0010]

As described above, the present invention has a structure in which the widthwise opening of the crucible corresponding to the widthwise direction of the substrate is divided into a plurality of openings. Then, the directivity of the vapor flow can be given by passing the vapor flow of the ferromagnetic metal through each of the divided openings, and in the magnetic layer at any position in the width direction formed on the wide substrate, in the film plane. It is possible to obtain an information recording medium in which the principal axes of anisotropic azimuths are aligned in the longitudinal direction of the information recording medium, the magnetic characteristics and electromagnetic conversion characteristics are improved, and the characteristics are made uniform in the width direction. Can be improved.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an information recording medium manufacturing apparatus according to an embodiment.

In the vacuum vapor deposition tank 1, a wide substrate 2 such as a polyester film is run from the unwinding roll 3 along the coating drum 4 to the winding roll 5.

The crucible 8 is irradiated with an electron beam 7 emitted from an electron gun 6, and the ferromagnetic metal 9 in the crucible 8 is heated and melted to evaporate. The magnetic layer is continuously deposited. Reference numeral 11 is a gas introduction nozzle, and 12 is an exhaust system.

2A and 2B are configuration diagrams of the crucible 8, wherein FIG. 2A is a top view, FIG. 2B is a side sectional view, and FIG.
6A is a sectional view taken along the line AA ′ of FIG.

The crucible 8 comprises a multi-chamber structure portion 13 corresponding to the upper portion in the depth direction and a single-chamber structure portion 14 corresponding to the lower portion. The wire- or pellet-shaped ferromagnetic metal material 9 is supplied from the material charging chamber 16 provided at the end of the crucible 8 and melted in the one-chamber structure portion 14 corresponding to the lower portion of the crucible. At this time, the electron beam 7 is irradiated by controlling the scanning pattern so that only the plurality of evaporation chambers 17 partitioned by the partition wall 18 are irradiated.

The vapor generated by the irradiation of the electron beam 7 passes through the evaporation chamber 17 of the multi-chamber structure portion 13 corresponding to the upper part of the crucible 8 and introduces a reactive gas such as oxygen gas from the gas introduction nozzle 11. , Is incident on the surface of the substrate 2 within a predetermined incident angle range to form a magnetic layer.

The position of the electron gun and the trajectory of the electron beam 7 are shown in FIG.
By forming the cutout portion 19a extending in the width direction of the crucible 8 on the crucible wall 19 on the electron beam irradiation side as described above, the crucible wall 19 can be substantially lowered.

In the multi-chamber structure portion 13 corresponding to the upper part of the crucible 8, by dividing the number of chambers into two or more chambers, the partition walls 18 formed between the chambers are obliquely evaporated in the width direction. By suppressing the progress of the incident vapor flow and limiting the evaporation range, the directivity of the vapor flow becomes good.

Metal vapor having a limited evaporation range adheres and deposits on the partition 18 and the upper part of the peripheral wall of the crucible 8. The deposited metal is melted by the electron beam 7, reflected electrons thereof, radiant heat in the crucible, and the like, and recirculates in the crucible 8. As a result, the vapor to the ineffective portion, which has been a problem in the past, is reduced, and the vapor deposition efficiency is greatly improved.

The interval between the partition walls 18, that is, the number of chambers in the multi-chamber structure portion 13 corresponding to the upper part of the crucible 8 and the width of the crucible 8 corresponding to the substrate carrying direction are designed to be appropriate according to the substrate width. Is desirable. In addition, the multi-chamber structure part 1
By increasing the depth of 3 (distance between the partition wall 18 and the surface of the molten metal), the directivity of the vapor flow and the recirculation action of the ineffective metal are improved.

The crucible 8 used in the present invention is preferably formed of a material having high heat resistance such as ceramics such as oxides, nitrides and carbides of magnesium and calcium.

The ferromagnetic metal material used in the present invention is a ferromagnetic metal selected from Fe, Co and Ni, or an alloy mainly containing them, such as Co-Ni and Co-.
Cr, Co-P, Co-Pt, Co-Ta, Co-Ni
There are many materials such as -Cr, Fe-Ni, Fe-Co, or those in which a trace amount of additional element is added.

As the heating means for evaporating the ferromagnetic metal in the crucible according to the present invention, a heating method using an electron beam irradiation with an electron gun, a heating method using a plasma irradiation gun, an induction heating method, or the like can be used.

Here, in order to confirm the effect of the present invention, FIG.
A magnetic layer was formed as described below using the vacuum vapor deposition apparatus shown in FIG. 2, and the magnetic characteristics were measured and the vapor deposition efficiency was calculated.

A polyethylene terephthalate film having a thickness of 6 μm and a width of 500 mm was set so that it could run as a substrate, pure cobalt was loaded into the crucible divided into five chambers corresponding to the upper part of the crucible, and a vacuum vapor deposition apparatus was set at 1 ×. 1
0 was evacuated to ⁵ Torr or less.

Next, the cobalt in the crucible was heated and melted by irradiating with an electron beam in a predetermined scanning pattern, and while introducing oxygen gas at 1000 ml / min, a magnetic layer having a thickness of 150 nm was formed and a magnetic layer having a length of 5000 m was formed. I made a tape roll.

For comparison, a magnetic layer was similarly formed in a manufacturing apparatus in which the multi-chamber structure portion 13 corresponding to the upper portion of the crucible was removed and a crucible having a single-chamber structure corresponding to the lower portion of the crucible was installed.

From these magnetic tape original fabrics, seven positions in the original fabric width direction were cut out, and the coercive force and the squareness ratio were measured using a sample vibrating magnetometer. The result is shown in FIG. In this figure, ● indicates the coercive force of the magnetic recording medium according to the example of the present invention, ○ indicates the coercive force of the magnetic recording medium of the comparative example, and ▲ indicates the squareness ratio of the magnetic recording medium according to the example of the present invention. , Δ indicates the squareness ratio of the magnetic recording medium of the comparative example.

As can be seen from this figure, in the present invention, both the coercive force and the squareness ratio have a good characteristic distribution in the original width direction, and particularly the squareness ratio is greatly improved.

Further, the torque curve in the film surface was measured at these tape width direction positions, and the magnetic anisotropy direction in the film surface was examined. The results are shown in FIG. As shown in the same figure, when the tape longitudinal direction is set to 0 degree, in the magnetic tape stock of the comparative example, the inclining angle of the in-plane anisotropy becomes larger toward the both ends of the substrate, as indicated by the circles. In contrast to a maximum of ± 14 degrees, the magnetic tape stock obtained in this example, indicated by ●, is less than ± 5 degrees, and there is very little variation in the width direction of the substrate.

From these results, it can be seen that in the magnetic tape manufactured in this example, the magnetic characteristics are improved and the characteristic distribution is improved at any position in the original width direction.

Further, the vapor deposition efficiency of the conventional one-chamber crucible was 9%, but the vapor deposition efficiency of the embodiment of the present invention was improved to 19%.

FIG. 6 is a top view of a magnetic card as an information recording medium, and FIG. 7 is a sectional view taken along the line CC ′ of FIG.

As shown in FIG. 6, a band-shaped recording layer 21 is embedded in a part of the card substrate 20. As shown in FIG. 7, the recording layer 21 is composed of a magnetic layer 22 and a substrate 23 arranged as a protective layer on the magnetic layer 22, and is manufactured using the apparatus shown in FIGS. Then, it is embedded in the card substrate 20.

FIG. 8 shows a modification of the partition of the crucible. By providing the partition 18 having a tapered shape whose thickness increases upward, the directivity of the evaporated metal can be further enhanced.

[0036]

As described above, according to the present invention,
Since the opening in the width direction of the crucible corresponding to the width direction of the base body is divided into a plurality of openings and the vapor stream of the ferromagnetic metal passes through each opening and is deposited on the base body, It is possible to obtain an information recording medium in which the directivity of a metal vapor flow is improved, the anisotropic azimuth is improved in any magnetic layer in the width direction formed on a wide substrate, and the magnetic characteristics are improved. it can. Further, most of the ineffective metal can be circulated in the crucible, so that the vapor deposition efficiency can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an apparatus for manufacturing an information recording medium according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a crucible used in the manufacturing apparatus.

FIG. 3 is a side view of the crucible in consideration of an electron beam irradiation angle and the like.

FIG. 4 is a characteristic diagram showing evaluation results of coercive force and squareness ratio of original magnetic tapes manufactured in Examples and Comparative Examples of the present invention.

FIG. 5 is a characteristic diagram showing evaluation results of in-plane anisotropic anisotropy directions of magnetic tape stocks produced in Examples and Comparative Examples of the present invention.

FIG. 6 is a top view of a magnetic card as an information recording medium.

FIG. 7 is a sectional view taken along the line CC ′ of FIG. 6;

FIG. 8 is a cross-sectional view showing a modified example of the partition of the crucible.

[Explanation of symbols]

 1 Vacuum Deposition Tank 2 Substrate 3 Unwinding Roll 4 Coating Drum 5 Winding Roll 6 Electron Gun 7 Electron Beam 8 Crucible 13 Multi-chamber Structure 17 Evaporation Chamber 18 Partition Wall

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryo Yano 1-88, Torora, Ibaraki-shi, Osaka Hitachi Maxell Co., Ltd. (72) Inventor Naoki Kitagaki 1-88, Torora, Ibaraki-shi, Osaka Hitachi Maxel Co., Ltd. (72) Inventor Hiroshi Shirai, 1-88, Torora, Ibaraki-shi, Osaka Hitachi Maxel Co., Ltd. (72) Inventor, Kunio Wakai, 1-88, Torora, Ibaraki-shi, Osaka Hitachi Ma Within Kucsel Co., Ltd.

Claims (2)

[Claims] 1. An apparatus for manufacturing an information recording medium, wherein a ferromagnetic metal in a crucible arranged in a vacuum chamber is heated to melt and evaporate, and the evaporated metal is vapor-deposited on a substrate to form a recording layer. An opening in the width direction of the crucible corresponding to the width direction of the base body is divided into a plurality of openings so that the vapor flow of the ferromagnetic metal passes through the divided openings and is deposited on the base body. An apparatus for manufacturing an information recording medium, comprising: 2. The apparatus for manufacturing an information recording medium according to claim 1, wherein the opening of the crucible is divided into a plurality of openings by a partition wall extending in the depth direction of the crucible.