JP2864780B2 - Manufacturing equipment for evaporated magnetic recording media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a vapor-deposited magnetic recording medium for vapor-depositing a metal thin film or the like which is optimal for high-density magnetic recording.

[0002]

2. Description of the Related Art In recent years, in the field of magnetic recording, high performance has been promoted with the aim of digitization, miniaturization and long time. A metal thin film type deposited magnetic recording medium in which the magnetic recording layer is formed of a ferromagnetic metal thin film has been actively studied because it is extremely advantageous for short wavelength recording.

[0003] The performance required for a vapor-deposited magnetic recording medium includes sensitivity, noise, distortion, and erasing characteristics, which are characteristics inherent to a magnetic material, and running performance and durability obtained by treating the front and back surfaces of a magnetic layer. However, there are other factors such as dropout, uneven magnetic properties, and uneven surface and back surface treatment which are influenced by the production control during vapor deposition. These must be strictly controlled for production as the recording density increases.

[0004] In particular, the signal loss in an extremely short time called dropout has a higher influence as the wavelength becomes shorter. The cause of the signal loss is a signal loss due to a partial defect (projection, pinhole, etc.) of the magnetic layer. Two factors can be considered: a case where a signal is lost due to a spacing caused by a foreign substance between the magnetic head and the vapor-deposited magnetic recording medium. Usually, dust in the process that is the source of foreign matter is well controlled,
Since there is a partial defect in the magnetic layer, it is not enough to completely eliminate the dropout simply by controlling the manufacturing process.

As a result of various studies on the source of this dropout, pinholes on the magnetic surface due to the splash (splashing) of the vapor deposition material that are rarely generated during vapor deposition,
It turned out that the protrusion was a factor. This splash is generated when the vapor deposition material attached to the deposition-preventing plate of the apparatus at the time of vapor deposition falls into the evaporation source. Hereinafter, a description will be given with reference to a vapor deposition section of an electron beam vapor deposition machine which is a conventional vapor deposition apparatus of this type shown in FIG.

That is, 1 is a plate-shaped shutter,
An opening 5 for vapor deposition formed by a lower protection plate 3 provided below the cooling can 2 and an upper protection plate 4 provided on the upper side is opened and closed. The base film 6 runs in the direction of the arrow along with the rotation of the cooling can 2 along the outer periphery of the cooling can 2. Reference numeral 7 denotes an evaporation source provided below the shutter 1, which is melted by the electron beam 8 and generates an evaporation material from the evaporation source 7.

[0007]

However, in the above-mentioned conventional configuration, when the shutter 1 is opened and the film is deposited on the base film 6, the shutter 1 is located immediately above the evaporation source 7, so that the amount of the deposited material is the largest. In addition, it has been found that the probability that the deposits fall into the evaporation source 7 is high, and that the dropouts are particularly problematic. In addition, as the length of the deposition process of the base film 6 increases, the amount of the base film 6 attached increases, and the amount and frequency of the separation also increase. At present, the processing length is inevitably limited due to such a problem, and this is an important issue in terms of quality and mass production of the evaporated magnetic recording medium.

For this reason, generally, there are many techniques for adjusting the cooling of the shutter 1 and the deposition-preventing plates 3 and 4 so as to increase the adhesion strength of the vapor deposition material to these components and to prevent the vapor deposition material from falling off. However, it is very difficult to control the cooling, and if the temperature is too high and the adhesion strength is too high, it will be extremely difficult to clean the inside of the deposition section, or if the temperature rises, the heat of the shutter 1 and the two protection plates 3 and 4 will be too high. In some cases, various obstacles may occur due to deformation or the like.

As described above, in addition to the processing conditions for determining the magnetic properties, a deposition prevention technique including cleaning of the inside of the tank of the deposition apparatus is indispensable as a mass production technique for the vapor deposition. It is important that the deposition-preventing plates easily adhere to the vapor deposition material during vapor deposition and are not easily peeled off, and that they are easily peeled appropriately during cleaning.

[0010] The present invention solves the above-mentioned problems, and when depositing a magnetic layer of a metal thin-film type magnetic recording medium, pinholes and dropouts caused by the detachment of deposits from the shutter even during long-time processing. It is an object of the present invention to provide an apparatus for producing a vapor-deposited magnetic recording medium capable of obtaining a good vapor-deposited magnetic recording medium with a small amount of magnetic flux.

[0011]

In order to achieve the above object, an apparatus for manufacturing a vapor-deposited magnetic recording medium according to the present invention comprises a shutter provided with an anti-deposition member formed in a comb shape close to a lower portion of a shutter body. It is composed. In addition, an attachment-preventing member is provided detachably at a lower portion of the shutter.

[0012]

According to the present invention, even if a large amount of vapor deposition material adheres to the lower portion of the shutter body during long-time vapor deposition, the vapor deposition material is very peeled off due to the anchor effect (support effect) of the comb-shaped adhesion member. It is hard to drop, and it is possible to completely prevent the deposited material from falling off during the deposition. In other words, the lower part of the shutter body can grow the vapor deposition material attached to the lower part of the shutter body into a relatively large bulk shape by adjusting the cooling of the shutter, and hold it with the anchor effect of the comb teeth of the deposition-inhibiting member. Since the temperature of the deposition material attached to the teeth is relatively high, it is difficult for the deposition material to be peeled off and does not fall off.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

The characteristic structure of this embodiment is that a comb-shaped deposition-inhibiting member is provided below the shutter body of the shutter described in the conventional example. The description of the same components as the conventional example is omitted.

FIG. 1 is a partial perspective view of the apparatus for manufacturing a vapor-deposited magnetic recording medium according to the present invention as viewed from below a shutter 11.
Comb-shaped protection members 12 formed in a comb shape close to the shutter main body 11a are integrally provided on opposite side walls 11b of the shutter main body 11a having a substantially U-shaped cross section. Numeral 12a denotes a comb tooth constituting the attachment-preventing member 12.

Such a shutter 11 is used in a vapor deposition section of a conventional electron beam vapor deposition machine shown in FIG. 3, and a vapor deposition magnetic recording medium obtained at that time and a conventional shutter 1 having no comb structure are used. The number of dropouts in the longitudinal direction was measured with the vapor-deposited magnetic recording medium obtained as described above, and the two were compared. The deposition conditions at this time were as follows: cobalt was introduced into the deposition material, the amount of oxygen introduced was 2.0 l / min, the base film was polyethylene phthalate having a thickness of 12 μm, and the deposition rate was 10
0 m / min, treatment length 10,000 m, deposition width 500 m
After completion of vapor deposition, the front and rear surfaces were subjected to a running treatment, cut into 8 mm widths, and measured for dropout of 15 μsec-16 dB.

FIG. 2 shows the result. The vertical axis represents the number of dropouts per minute, the horizontal axis represents the processing length of vapor deposition, A represents the evaporation magnetic recording medium obtained by using the shutter 11 of the present invention, and B represents the vapor deposition magnetic recording obtained by using the conventional shutter 1. Medium. In the case of the conventional shutter 1, in the longitudinal direction of vapor deposition, abnormal spots of dropout are often found,
When abnormal spots of dropout were confirmed by bitter development, it was found that most were pinhole factors.

As described above, according to the present embodiment, the shutter 11 is provided close to the lower portion of the shutter main body 11a and the comb-shaped deposition-preventing member 12 is provided so that the vapor deposition material adhered to the lower surface of the shutter main body 11a can be removed by the shutter. The growth of the bulk material can be held by the comb teeth 12a by controlling the cooling temperature of 11, and the vapor deposition material attached to the comb teeth 12a has a relatively high temperature of the comb teeth 12a itself. Adhesive strength is high and does not peel off during use.

Therefore, splash due to the partial falling-off of the vapor deposition material from the shutter 11 is prevented, and it is possible to provide a vapor deposition magnetic recording medium with less dropout.

The pitch, length, thickness, material, and the like of the comb teeth 12a of the deposition-inhibiting member 12 need only have a length to which the vapor deposition material can adhere and a strength that can withstand the weight of the vapor deposition material.

In this embodiment, the comb-shaped prevention member 12 is integrally provided below the shutter main body 11a of the shutter 11. However, the prevention member 12 is attached to the side walls 11b with mounting screws or the like.
May be provided detachably. In this case, since the vapor deposition material adhered to the shutter body 11a and the comb teeth 12a can be disassembled during cleaning, cleaning can be performed more easily and reliably, and the quality of vapor deposition on the base film 7 can be improved. Can be.

[0022]

As described above, according to the apparatus for manufacturing a vapor-deposited magnetic recording medium of the present invention, by providing a comb-shaped anti-adhesion member close to the lower portion of the shutter body, the shutter section can be used even during long-time vapor deposition. The pinhole due to the splash which causes the dropout can be remarkably reduced without the vapor deposition material adhered to the surface falling off. In addition, in terms of production, excellent effects can be obtained in terms of quality and production, for example, cleaning after deposition is very easy.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a lower portion of a shutter of an apparatus for manufacturing a deposited magnetic recording medium according to an embodiment of the present invention.

FIG. 2 is a view showing a measurement result of the number of dropouts of a vapor-deposited magnetic recording medium obtained by the vapor deposition manufacturing apparatus in comparison with a conventional example.

FIG. 3 is a schematic configuration diagram of a vapor deposition unit of a conventional apparatus for vapor deposition of a vapor-deposited magnetic recording medium.

[Explanation of symbols]

 5 Opening 11 Shutter 11a Shutter body 12 Deposition member

Claims (2)

(57) [Claims] A base film is provided along a cooling can,
Evaporation material evaporated from the evaporation source is deposited on the base film
An apparatus for manufacturing a vapor-deposited magnetic recording medium, comprising:
A vapor-deposited magnetic recording medium comprising: a shutter for opening and closing a vapor-deposition opening between a fan and the evaporation source ; and a comb-shaped anti-adhesion member provided near the lower part of the shutter body. Manufacturing equipment. 2. The apparatus for manufacturing a vapor-deposited magnetic recording medium according to claim 1, wherein the deposition-inhibiting member is detachably provided below the shutter body.