JPH04346665A - Electron beam heating type vapor deposition device - Google Patents

Abstract

PURPOSE:To effectively avert the trouble of static electricity even in a vacuum by providing an insulator layer on the surface of a cylindrical roll of the electron beam heating type vapor deposition device which continuously forms a vapor deposited film on a long-sized film traveling on the cylindrical roll. CONSTITUTION:The insulator layer 13 made of polyimide having, for example, 25mu thickness is provided by thermocompression molding on the peripheral surface of the cylindrical roll 4. The formation of the vapor deposited film on the film 2 is executed by rotating the respective rolls and allowing the film 2 to travel after the evacuation of the inside of the device body 1 to a vacuum. The electron beam emitted from an electron gun 11 is brought into collision against a material 9 for vapor deposition to form the vapor deposited film on the surface 12 of the film 2 traveling on the roll 4. Even if the film 2 is electrified to a minus by the inflow of the reflected electrons reflected at the time of the collision of the electron beam against the material 9 for vapor deposition and the secondary electrons released at this time flow into the film 2, the peripheral surface of the roll 4 is constituted of the insulator layer 13 and, therefore, this part is not electrified to a plus. Then, the generation of the discharge traces of the film 2 and the damage of the film 2' and the vapor deposited film are prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam heating type vapor deposition apparatus used for forming a thin film on a film made of a polymeric material.

0002

2. Description of the Related Art Conventionally, an apparatus as shown in FIG. 2 has been used to continuously form a thin film on a film made of a polymeric material by an electron beam heating method.

[0003] In this device, an unwinding roll 3 for continuously unwinding a long film 2 and a cylinder for forming a thin film on the film 2 are installed in an evacuable device body indicated by the reference numeral 1. A winding roll 4 and a winding roll 5 for continuously winding up the film 2 are provided, and between the unwinding roll 3 and the cylindrical roll 4 and between the cylindrical roll 4 and the winding roll 5. is provided with auxiliary rolls 6 for making the film 2 run smoothly. Such rolls, including the cylindrical roll 4, are generally made of metal with good thermal conductivity. Also,
The main body 1 of the apparatus is partitioned approximately at the center by a heat shielding plate 7,
An electron beam evaporation source 10 is disposed below the heat shielding plate 7 in the drawing at a position facing the film forming surface 12 of the film 2 running on the cylindrical roll 4 . This electron beam evaporation source 10 includes an evaporation material 9 and a crucible 8. An electron gun 11 for emitting an electron beam toward the vapor deposition material 9 is installed on the right side of the apparatus main body 1 in the figure.

When performing vapor deposition using such an apparatus, after evacuation of the apparatus main body 1, each roll is rotated to run the film 2, and an electron beam is emitted from the electron gun 11 for vapor deposition. Fire towards material 9. Then, the film 2 is continuously unwound from the supply roll 2, travels in the direction of the arrow, passes through the auxiliary roll 6, and is transferred to the cylindrical roll 4.
move along the circumference of the On the other hand, the emitted electron beam collides with the vapor deposition material 9 along the trajectory shown in the figure. Therefore, the vapor deposition material 9 sublimes, melts, and evaporates to form a vapor deposition film on the film forming surface 12 of the film 2 running on the cylindrical roll 4 . The film 2 on which the vapor deposited film has been formed is wound up onto a winding roll 5 via an auxiliary roll 6.

[0005]

[Problems to be Solved by the Invention] As mentioned above, in this device, the electron beam emitted from the electron gun is directed to the evaporation material 9.
The vapor deposition material 9 is sublimated, dissolved, or evaporated by colliding with the vapor deposition material 9. However, when the accelerated and high-energy electrons collide with the vapor deposition material 9, not all of the electrons give their energy as heat to the vapor deposition material 9, and in reality, some electrons become high-energy. They may be reflected as they are, or they may emit secondary electrons after a collision. Such reflected electrons and secondary electrons reach the film 2 on which the vapor deposited film is to be formed, and the film 2 is negatively charged. Furthermore, if the emission current of the electron beam is further increased in order to increase the amount of evaporation, the amount of charge on the film 2 will further increase.

[0006] When the film 2 is negatively charged in this way, the cylindrical roll 4 that is in contact with the film 2 is supplied with an amount of positive charge commensurate with the amount of charge. For this reason, when the cylindrical roll 4 and the film 2 are separated, discharge occurs and discharge marks are left on the film 2, and the cylindrical roll 4
In some cases, the film 2 and the deposited film were damaged due to the electrostatic attraction between the film 2 and the film 2.

[0007] Therefore, in order to eliminate the charge from the film 2 that has been charged during such vapor deposition, glow discharge treatment, ion irradiation,
Methods such as using a static elimination brush are being considered.

However, although glow discharge treatment is effective in a reduced pressure atmosphere, it is difficult to perform discharge in a high vacuum. There is also the disadvantage that the discharge gas affects the quality of the deposited film. Ion irradiation also basically requires the introduction of a gas, which has the disadvantage that the gas affects the quality of the deposited film, similar to the case of glow discharge treatment. Moreover, when applied to a large area, the cost becomes high. There is a complaint that static elimination brushes are effective in the atmosphere, but have little static elimination effect in a vacuum.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electron beam heating type vapor deposition apparatus that can effectively avoid problems with static electricity even in a vacuum.

0010

[Means for Solving the Problems] In the electron beam heating vapor deposition apparatus of the present invention, a means for solving the problems is to provide an insulating layer on the circumferential surface of a cylindrical roll.

The insulating layer may be made of polymer materials such as polyimide, polyester, polypropylene, alumina,
Ceramic materials such as silica, titania and zirconia are suitable. Further, the insulating layer can be easily provided on the circumferential surface of the cylindrical roll by thermocompression bonding, welding, adhesion, or the like.

0012

[Operation] When an insulating layer is provided on the circumferential surface of a metal cylindrical roll (conductor) and a polymer film (insulating layer) is brought into contact with it, reflected electrons and secondary electrons flow into the film. Even if the film becomes negatively charged, since the circumferential surface of the cylindrical roll is constituted by an insulating layer, this portion will not be positively charged.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electron beam heating type vapor deposition apparatus of the present invention will be explained in detail below with reference to the drawings. Note that the same reference numerals are given to the same components as those of the conventional device to simplify the explanation.

FIG. 1 is a schematic diagram showing an embodiment of the electron beam heating type vapor deposition apparatus of the present invention. In this device, as in the conventional example, an unwinding roll 3, a cylindrical roll 4, and a take-up roll 5 are provided in the main body 1 of the device, and between the unwinding roll 3 and the cylindrical roll 4, Auxiliary rolls 6 are provided between the winding roll 5 and the winding roll 5. Further, the circumferential surface of the cylindrical roll 4 has a thickness of 25 mm.
An insulating layer 13 made of polyimide having a thickness of .mu.m is provided by thermocompression bonding. The apparatus main body 1 is partitioned approximately at the center by a heat shield plate 7, and below the heat shield plate 7, a vapor deposition material 9 and a crucible 8 are placed at a position facing the film forming surface 12 of the film 2 running on the cylindrical roll 4. An electron beam evaporation source 10 including an electron beam evaporation source 10 is arranged. An electron gun 11 for emitting an electron beam toward the vapor deposition material 9 is installed on the right side of the apparatus main body 1 in the figure.

When forming a vapor deposited film on the film 2 using the apparatus configured as described above, first, as in the conventional apparatus, the inside of the apparatus body 1 is evacuated, and then each roll is evacuated. is rotated to run the film 2, and an electron beam is emitted from the electron gun 11 toward the vapor deposition material 9. Then, the emitted electron beam collides with the vapor deposition material 9 and sublimates, melts, and evaporates the vapor deposition material 9, thereby forming the film forming surface 12 of the film 2 running on the cylindrical roll 4.
to form a deposited film.

Here, even if the backscattered electrons reflected and the emitted secondary electrons flow into the film 2 when the electron beam collides with the vapor deposition material 9 and the film 2 becomes negatively charged,
Since the circumferential surface of the cylindrical roll 4 is constituted by the insulating layer 13, this portion is not positively charged.

Therefore, according to this device, the cylindrical can 4
When the film 2 and the film 2 are peeled off, no discharge occurs, and discharge marks on the film 2 can be prevented. Also,
Since no electrostatic attraction acts between the cylindrical roll 4 and the film 2, there is no fear that the film 2 or the deposited film will be damaged.

(Experimental example) A polyester film 2 having a thickness of 12 μm and a width of 500 mm was set in the apparatus main body 1 with the distance between the evaporation source 10 and the film forming surface 12 set at 250 mm and the exhaust gas at 2×10 −5 Torr. was run at a speed of 10 m/min. As the electron beam acceleration method, an electron impact cathode self-acceleration method was used, with an acceleration voltage of 30 kV and an emission current of 0.8 A. Silicon dioxide was used as the vapor deposition material 9, and the electron beam was scanned over the vapor deposition material 9 with a scanning width of 500 mm. In addition, an insulating layer 13 is formed on the circumferential surface of the cylindrical roll 4, each having a thickness of 25 μm.
m polyimide, 50 μm thick polyester, thickness 2
μm silica was formed. Using the cylindrical roll 4 on which each insulator layer 13 is formed in this way, the film 2
The degree of damage to Film 2 was compared when a vapor-deposited film was formed. Furthermore, as a comparative example, the results were also compared using a cylindrical roll 4 without the insulator layer 13 formed thereon. The results are shown in Table 1.

[Table 1] (○: Almost no damage to the film ×: Damaged to the extent that it cannot be used for practical purposes)

From these results, it was found that by providing the insulating layer 13 on the surface of the cylindrical roll 4, damage to the film could be prevented.

[0020]

[Effects of the Invention] As explained above, in the electron beam heating type vapor deposition apparatus of the present invention, since an insulating layer is provided on the circumferential surface of the cylindrical roll, reflected electrons and secondary electrons do not flow into the film. Even if the film is negatively charged, the peripheral surface of the cylindrical roll is not positively charged.

[0021] Therefore, according to this device, no discharge occurs when the cylindrical roll and the film are separated, and it is possible to prevent discharge marks from being formed on the film. In addition, since there is no electrostatic attraction between the cylindrical roll and the film,
Damage to the film or deposited film can be prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of an electron beam heating type vapor deposition apparatus of the present invention.

FIG. 2 is a schematic diagram showing a conventional electron beam heating type vapor deposition apparatus.

[Explanation of symbols]

1　　　　　Device body 2 Film 4 Cylindrical roll 13 Insulator layer

Claims (1)

[Claims] 1. An evaporation source placed opposite the surface of a long film running along the circumferential surface of a cylindrical roll is heated and evaporated by an electron beam, and a vapor-deposited film is formed on the long film. 1. An electron beam heating type vapor deposition apparatus for continuously forming a cylindrical roll, characterized in that an insulating layer is provided on the circumferential surface of the cylindrical roll.