JPH10251843A - Vacuum evaporation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of an abnormal discharge between the mounting stays of a discharge device for activating the surface of a base film and a cooling roll by disposing a stay cover consisting of an insulating material on the surfaces of the stays facing the cooling roll. SOLUTION: The discharge device 52 is arranged to face the prescribed position of the cooling roll 3 in order to activate the surface of the nonmagnetic base film. The discharge device 52 is provided with the metallic cover 56 via insulators 55 so as to cover an electrode 54. The metallic stays 57 are connected to both side ends of this cover 56. The stay cover 58 consisting of the insulating material is so disposed as to cover the surfaces of the stays 57 facing the cooling roll 3. A polyacetal resin to allow high-accuracy processing is used for the stay cover 58. A gas introducing pipe 60 is disposed between the electrode 54 and the cooling roll 3. As a result, the damage of the base film by the abnormal discharge is prevented and a working rate and the production yield of magnetic recording medium media are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum deposition apparatus for producing a magnetic recording medium, and more particularly to a discharge apparatus used for activating the surface of a non-magnetic base film.

[0002]

2. Description of the Related Art Conventionally, for example, in a video tape recorder, image quality has been improved by high-density recording. To cope with this, for example, a metal magnetic thin film is used as a magnetic recording medium for an 8 mm VTR. A vapor deposition tape as a layer has been put to practical use.

[0003] Evaporated tapes have better magnetic properties than coating type magnetic tapes that have been widely used so far.
Since the thickness of the magnetic layer is also small, it is expected that the magnetic layer will exhibit performance superior to that of the coating type magnetic tape in terms of electromagnetic conversion characteristics.

[0004] Unlike the coating type tape, such a vapor deposition tape is manufactured by dissolving a magnetic metal material such as Co-Ni in a vacuum vapor deposition apparatus and uniformly adhering the vapor to the surface of the non-magnetic base film.

[0005] As a general method of manufacturing such a vapor deposition tape with a vacuum vapor deposition apparatus, FIG. 5 shows a vapor deposition apparatus called oblique vapor deposition. The vacuum evaporation apparatus 1 includes an unwind roller 4 and a take-up roller 5 having a non-magnetic base film 40 wound thereon in a vacuum chamber 2, a cooling roll 3 for guiding the non-magnetic base film 40 while cooling, and the cooling roll 3. A crucible 6 containing a magnetic metal 11 is disposed below the crucible 3.

In the vicinity of the cooling roll 3,
An oxygen introducing pipe 9 for supplying oxygen gas is disposed between the shutter 8 and the cooling roll 3 and the shutter 8 for defining the incident angle of the evaporated metal. Further, a discharge device 14 for activating the surface is arranged to face a predetermined position of the cooling roll 3 (that is, a position corresponding to a position before the vapor deposition position). The inside of the vacuum chamber 2 is evacuated from an exhaust port 13 by a vacuum pump. 10 is a non-magnetic base film 4
The guide guide roller 7 is an electron gun provided outside the vacuum chamber 2 as a means for evaporating the magnetic metal 11.

As shown in FIG. 6, the discharge device 14 is provided with an electrode 23 facing the cooling roll 3 with a required gap.
And a cover 21 that covers the top and side surfaces of the electrode 23 via an insulating insulator 22, a stay 20 located on both sides of the electrode 23 and connected to the cover 21, and gas introduction for introducing, for example, oxygen gas into the discharge device 14. The discharge device 14 is positioned and attached by the stay 20.

In the vacuum evaporation apparatus 1, the unwind roller 4
The non-magnetic base film 40 sent out of the apparatus is transported in the direction of the arrow while being guided by the cooling roll 3, and the surface of the non-magnetic base film 40 is activated by the discharge device 14. Next, the metal 11 in the crucible 6 melted by the electron beam B emitted from the electron gun 7 becomes a vapor and is deposited on the non-magnetic base film 40 cooled by the cooling roll 3.

The vaporized metal is obliquely vapor-deposited by restricting the incident angle of the metal vapor by a shutter 8 provided near the cooling roll 3, and is further oxidized by oxygen supplied by an oxygen introduction pipe 9 to be oxidized. A metal thin film defined by the magnetic properties of The base film 40 on which the metal thin film is deposited is further cooled by the cooling roll 3 and then wound up by the winding roller 5.

[0010]

In the discharge device 14, the gap between the stay 20 and the cooling roll 3 is set to 1 to 3 mm so that the gas introduced into the discharge device does not easily leak.

Since the cover 21 and the stay 20 are made of metal, the electrode 23 is attached through an insulating insulator 22. However, the distance between the cover 21 and the stay 20 and the electrode 23 cannot be made large because of the structure. It is about. If the insulation resistance between the stay 20 and the cooling roll 3 is small, abnormal discharge occurs, and the base film 40 in contact with the cooling roll 3 is damaged. There was a problem that it would. In this case, since the vapor deposition cannot be continued, the operation rate decreases.

The present invention prevents such abnormal discharge,
An object of the present invention is to provide a vacuum deposition apparatus that prevents a reduction in the operation rate and yield due to perforation of a base film.

[0013]

The vacuum deposition apparatus of the present invention has a structure in which a stay cover made of an insulating material is provided on a surface of a mounting stay of a discharge device provided in this device, which is opposed to a cooling roll. As described above, by covering the stay of the discharge device with the insulating material, it is possible to prevent abnormal discharge between the stay and the cooling roll.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A vacuum deposition apparatus according to the present invention is provided with a cooling roll for guiding a non-magnetic substrate and a discharge device for activating the surface to deposit a deposition material on the non-magnetic substrate. A stay cover made of an insulating material is provided on the surface of the mounting stay of the discharge device facing the cooling roll.

According to the present invention, in the above-described vacuum deposition apparatus, a polyacetal resin is used as an insulating material.

Hereinafter, an embodiment of a vacuum deposition apparatus according to the present invention will be described with reference to the drawings.

First, FIG. 4 shows the structure of a magnetic recording medium obtained by the vacuum vapor deposition apparatus of this embodiment, that is, a vapor deposition tape having a metal magnetic thin film as a magnetic layer. The vapor deposition tape 43 is provided on one surface of a non-magnetic base film 40 which is a non-magnetic substrate.
The metal magnetic thin film 41 is deposited. It is preferable that a back coat layer 42 indicated by a virtual line is formed on the other surface of the nonmagnetic base film 40.

The base film 40 is a non-magnetic plastic film, usually made of polyethylene terephthalate or the like and having a thickness of about 10 μm.

As the ferromagnetic metal material used for forming the magnetic metal thin film 41, in addition to metals such as Fe, Co, Ni, and Cr, a Co—Ni alloy, a Co—Pt alloy,
-Ni-Pt alloy, Fe-Co alloy, Fe-Ni alloy,
Fe-Co-Ni alloy, Fe-Co-B alloy, Co-N
An i-Fe-B alloy, or an alloy containing a metal such as Cr, Al, or the like, may be used. The thickness of the metal magnetic thin film 41 is usually 0.02 to 1 μm.

The material of the back coat layer 42 has a pH of 6.0 or more (particularly 6.0 to 10.0) and a D
Carbon black having a BP lubricating amount of 80 cc / 100 g or less is preferable in terms of good durability, antistatic properties and prevention of rust. The thickness of the back coat layer is 0.4 to 1.2 μ
m.

FIG. 1 shows an embodiment of a vacuum deposition apparatus according to the present invention. The vacuum deposition apparatus 51 according to the present embodiment cools the non-magnetic base film 40 while cooling the unwind roller 4 and the take-up roller 5 around which the non-magnetic base film 40 is wound in the vacuum chamber 2 as described above. A cooling roll 3 to be guided and a crucible 6 containing a magnetic metal (for example, a Co—Ni alloy) are disposed below the cooling roll 3.

Further, a shutter 8 for defining an incident angle of the evaporated metal in the vicinity of the cooling roll 3 and an oxygen introducing pipe 9 for supplying oxygen gas between the cooling roll 3 and the shutter 8 are arranged. Air is exhausted from the port 13 by a vacuum pump. 10 is a guide roll for guiding the non-magnetic base film 40, 7 is a magnetic metal 1
An electron gun provided outside the vacuum chamber 2 as a means for evaporating 1.

In this embodiment, in particular, the surface of the nonmagnetic base film 40 is activated facing a predetermined position of the cooling roll 3 in the vacuum chamber 2 (ie, a position corresponding to a position just before the vapor deposition position). New discharge device 5 for causing
2 is arranged.

As shown in FIGS. 2 and 3, the discharge device 52 is provided with a metal cover 56 via an insulating insulator 55 so as to cover the electrode 54. Metal covers 56 are provided on both ends of the cover 56. The stay 57 is connected and the stay 5 is connected.
A stay cover 58 made of an insulating material is provided so as to cover the surface facing the cooling roll 3.

As shown in FIG. 3, for example, the stay cover 58 is formed in a U-shaped section so as to cover the lower surface and both sides of a rectangular parallelepiped stay 57, and is fixed to the stay 57 by bolts 59. The discharge device 52 is provided with a gas introduction tube 60 for facilitating discharge between the electrode 54 and the cooling roll 3. The stay 58 is used for positioning and attaching the discharge device 52.

The material of the insulating material of the stay cover 58 is not particularly limited as long as it does not violate the object of the present invention. For example, a polyacetal resin which can be processed with high precision is preferable. Delrin (a trade name of polyacetal resin manufactured by Du Pont), which is a kind, is suitable. The shape of the stay cover 58 and the stay 5
There is no particular limitation on the method of fixing to the stay 7 as long as it can be configured with high precision, and it may be fixed by bolts 59 in a shape following the shape of the stay 57, or may be fixed by an appropriate method such as fixing with an adhesive. It is also possible.

The vacuum deposition apparatus 51 operates in the same manner as described above. That is, the base film 40 sent out from the unwinding roller 4 is transported while being cooled along the cooling roll 3 while being given an appropriate tension, and is wound up by the winding roller 5 via the guide roller 10. During the transfer of the base film 40, discharge is performed between the discharge device 52 and the cooling roll 3, and the base film 40 is discharged.
Is activated.

Next, the magnetic metal 11 is melted by the electron beam B emitted from the electron gun 7, and the evaporated metal is deposited on the base film 40 whose surface is activated.

The vaporized metal is obliquely vapor-deposited at a limited incident angle by a shutter 8 provided in the vicinity of the cooling roll 3, and further has a predetermined degree of oxidation by oxygen supplied from an oxygen introduction pipe 9. A metal thin film having the following magnetic properties. That is, this is the metal thin film 41 shown in FIG.
Becomes

According to the vacuum deposition apparatus 51 of the above-described embodiment, the stay 54 of the stay 57 of the discharge device 52 is provided with the stay cover 58 made of an insulating material, so that, for example, the electrode 54 and the cover 56 are provided. Even if the insulation resistance between the stay 57 and the stay 57 is reduced, abnormal discharge between the stay 57 and the cooling roll 3 can be prevented. Therefore, the base film 40 is not damaged,
There is no inconvenience that a hole is opened by burning due to heat at the time of deposition. As a result, equipment stoppage due to a hole in the base film 40 is eliminated, and a reduction in the operation rate and yield can be prevented.

[0031]

According to the present invention, an abnormal discharge between the stay and the cooling roll can be prevented by using an insulating structure for the discharge device mounting stay. Therefore, equipment stoppage due to a hole or the like in the base film due to abnormal discharge is eliminated, and the operation rate and the production yield of the magnetic recording medium can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a vacuum evaporation apparatus according to the present invention.

FIG. 2 is an enlarged perspective view of a discharge device used in the present invention.

FIG. 3 is a perspective view of a stay and a stay cover used in the present invention.

FIG. 4 is a sectional view of a deposition tape obtained by the vacuum deposition apparatus of the present invention.

FIG. 5 is a configuration diagram showing an example of a conventional vacuum evaporation apparatus.

FIG. 6 is an enlarged perspective view of a conventional discharge device.

[Explanation of symbols]

1,51 vacuum evaporation apparatus, 2 vacuum tank, 3 cooling roll, 4 unwind roller, 5 take-up roller, 6
Crucible, 7 electron gun, 8 shutter, 9 oxygen introduction pipe, 10 guide roller, 13 exhaust port, 14, 52
Discharge device, 20,57 stay, 21,56 cover,
22, 55 insulation insulator, 23, 54 electrode, 24, 6
0 gas introduction pipe, 40 base film, 41 metal magnetic thin film, 42 back coat layer, 58 stay cover,
59 fixing bolt, B; electron beam

Claims (2)

[Claims] 1. A vacuum deposition apparatus comprising a cooling roll for guiding a non-magnetic substrate and a discharge device for surface activation, and for depositing a magnetic material on the non-magnetic substrate. On the opposite surface of
A vacuum deposition apparatus comprising a stay cover made of an insulating material. 2. The vacuum deposition apparatus according to claim 1, wherein a polyacetal resin is used as the insulating material.