JP4161607B2 - Retractable electron beam vacuum evaporation system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a take-up electron beam vacuum deposition apparatus for depositing an evaporation material such as an insulating metal oxide on a film surface for the purpose of imparting characteristics that cannot be achieved by a single unit such as a plastic film.
[0002]
[Prior art]
In recent years, new materials for various industrial uses in which metal, organic / inorganic compounds, etc. are formed on a film surface by various film forming techniques have been developed in order to impart characteristics that cannot be achieved by a single unit such as a plastic film. There are various methods for depositing various materials, but the method for depositing a thin film of metal, metal oxide or the like as in the present invention depends on the vacuum evaporation source or ion plate depending on the classification of the vacuum evaporation source. Such as a sputtering method and a sputtering method. In particular, when the substrate for vapor deposition such as a plastic film is a web sheet, a thin film deposition method by vacuum vapor deposition is widely used.
[0003]
There are three types of vacuum deposition methods, depending on the form of the deposition target: (1) batch method: vapor deposition method for molded products, (2) take-up semi-continuous method: vacuum for roll-shaped web sheets After unwinding, vapor deposition, and winding in the system, return to the atmospheric system again and take out the evaporated product. (3) Unwinder (unwinding device) for roll-up web sheet And a rewinder (winding device) placed in the air system, and the evaporation drum and evaporation source are placed in a vacuum system to evaporate the evaporated material on the roll-shaped web sheet. This is a completely continuous method called a method with high productivity.
[0004]
When evaporating an evaporation substance on a roll-shaped web sheet, a take-up semi-continuous method is particularly popular. The components of the take-up vacuum deposition apparatus and the outline of the work process will be described, and the internal structure of the vacuum deposition apparatus will be described. First, the constituent elements are a roll-shaped web sheet, an evaporation source, an evaporation substance, a vapor deposition drum, a vacuum system, an unwinder (unwinding device), a rewinder (winding device), a guide roll, and the like.
[0005]
Next, an outline of the work process will be described. First, as a preparation, open the door of the vacuum deposition device, set a web sheet such as a roll-shaped plastic film on the unwinder (unwinding device), through a guide roll disposed between the unwinder and the deposition drum, The web sheet travels to the vapor deposition drum, and is further wound around a rewinder (winding device) via a guide roll arranged between the rewinder (winding device) and vapor deposition of the evaporated substance on the web sheet is performed. Preparation is complete.
[0006]
Next, the door of the vacuum vapor deposition apparatus is closed, and the vacuum vapor deposition chamber divided by the vacuum suction constant pressure chamber and the partition in the vacuum vapor deposition apparatus is made into a predetermined vacuum environment by a vacuum pump. The web sheet is unwound from an unwinder, and evaporated on the web sheet by various methods to heat and evaporate evaporation materials from an evaporation source disposed at the lower part of the deposition drum on the web sheet that has been run through a guide roll. Let Since the deposition drum is cooled, the evaporated substance is recrystallized and fixed to the web sheet. Further, the web sheet deposited through the guide roll on the rewinder side is wound around the rewinder.
[0007]
The internal structure of the vacuum deposition apparatus is divided into a vacuum suction constant pressure chamber and a vacuum deposition chamber by partition walls. In the vacuum suction constant pressure chamber, an unwinder, a guide roll, a tension control device, a speed control device, a position control device, a part of a vapor deposition drum, a rewinder, and the like are arranged. In the vacuum deposition chamber, a part of a deposition drum, an evaporation source, a heating device for the evaporation source, and the like are arranged. The vacuum suction constant pressure chamber has a degree of vacuum of about 1 × 10 ⁰ MPa and a vacuum deposition chamber provided via a partition wall is 1 × 10 ⁻² MPa (by a vacuum pump attached to the periphery of the vacuum deposition apparatus main body. SI unit). Since the two chambers are divided by the partition walls, impurities (dust) such as gas generated from the web sheet in the vacuum suction constant pressure chamber are unlikely to adversely affect the deposition in the vacuum deposition chamber. On the contrary, the radiant heat from the evaporation source arranged in the vacuum deposition chamber has little influence on the vacuum suction constant pressure chamber, and therefore the influence of the heat on the web sheet is small.
[0008]
Recently, the purpose of vapor deposition of the evaporating material on the web sheet is just a decorative purpose to give a metallic luster or an alternative to aluminum foil with gas barrier properties, special chemical performance such as adsorbing odors, or anti-reflection of light Thin film deposition on the web sheet for the purpose of imparting special physical performance is increasing. Therefore, it is an important factor for obtaining a thin film with good quality that the web sheet itself and the evaporation material as a base material are adapted to the application, required quality, and film forming conditions.
[0009]
For example, when the web sheet suitable for the vacuum deposition method is described, the following is required. (1) Do not release gases such as moisture, residual solvent, plasticizer, and unreacted monomer as much as possible in a vacuum environment in order to improve the adhesion to the evaporated material and improve the smoothness of the vapor deposition surface. ▼ In order to improve the adhesion to the evaporating substance, the surface of the web sheet must be compatible with the evaporating substance. (3) The radiant heat from the evaporation source and the heat of condensation of the evaporating substance cause the web sheet to undergo thermal contraction deformation. It must have heat resistance to prevent it from occurring. (4) Since the vapor deposition process is continuously performed in a roll shape, the web sheet has a uniform thickness in order to prevent wrinkles, sagging and hardness unevenness in the meantime, and to prevent wrinkles and winding deviation of the web sheet. In addition, the web sheet is required to have an appropriate sliding property.
[0010]
At present, plastic films made of polyolefin resins such as polyester films (polyethylene terephthalate) and polypropylene films are used as web sheets that can relatively meet these requirements.
[0011]
Next, the evaporation material that serves as the evaporation source has traditionally been mainly made of simple metals such as aluminum (Al), but the web sheet has barrier properties, environmentally friendly ecology, and food packaging. The need to use insulating metal oxides such as silicon oxide (SiO ₂ ) and alumina (Al ₂ O ₃ ) for the purpose of having the performance of being able to cook using a microwave oven in the state Came out.
[0012]
The vacuum deposition method is also determined by the heating method: (1) indirect resistance method, (2) direct resistance heating method (wire feed method), (3) high frequency induction heating method, (4) electron beam method (EB for short) 4), the electron beam method is most suitable when the evaporated substance uses an insulating metal oxide such as silicon oxide or alumina.
[0013]
The take-up electron beam vacuum deposition method is a method in which an evaporated material is directly irradiated with an electron beam to heat and evaporate. In particular, the evaporated material is attracting attention as a vacuum deposition method of an insulating metal oxide such as silicon oxide or alumina. Yes. The electron beam is a heat source that heats the surface of the evaporating material, scans the surface of the evaporating material, converts energy at the portion hit by the electron beam, and evaporates the evaporating material. The greatest feature of the electron beam is that not only high melting point metals but also insulating metal oxides such as silicon oxide and alumina can be deposited.
[0014]
When the evaporating substance is a conductor such as a simple metal, the glow discharge plasma treatment of the web sheet, which is performed for the purpose of improving the adhesion of the deposited film, was effective in removing the charge. However, in the case of an evaporating substance such as insulating silicon oxide or alumina, a large amount of secondary electrons emitted from the evaporating substance are generated along with the electron beam irradiation to the evaporating substance, and the web sheet Therefore, it is pointed out that when the web sheet is peeled from the vapor deposition drum, the discharge discharge due to charging occurs and the vapor deposition film is damaged or destroyed. Yes.
[0015]
As measures against these, for example, as shown in Japanese Patent Application Laid-Open No. 05-86470, the polarity of the surface of the insulator film is measured, a potential having a polarity opposite to the charging polarity is applied to remove the initial charging, and further the high frequency Evaporation of vaporized material made of an insulating material by performing further electrification removal and negative potential treatment between the unwinding roll and the coating drum by glow discharge plasma, and making the insulator film surface a uniform negative potential. There is a method of suppressing peeling discharge from the coating drum caused by charging of the insulating film by secondary electrons by a method of electrically repelling incident secondary electrons and reducing incidence.
[0016]
Further, as disclosed in Japanese Patent Application Laid-Open No. 07-150355, after being deposited on a base material such as a polymer film, a conductive auxiliary that is grounded so as to be in contact with the deposition drum at a portion where it is peeled off from the deposition drum Various solutions have been proposed in order to solve the problems caused by charging of the web sheet, such as a method of removing electricity by a roll, and the peeling discharge when the web sheet is peeled from the vapor deposition drum has been suppressed.
[0017]
However, even with these methods, the secondary electrons emitted from the evaporated substance cannot be completely removed from the web sheet, and the negative charge of the secondary electrons that remain charged on the web sheet is immediately before being wound up by the rewinder. Winding tension causes slip friction between the front and back of the web sheet, abnormal discharge occurs with the energy, the front and back of the web sheet are melted, and the web sheets are welded (blocked) to damage or break the deposited film. A new problem has been pointed out.
[0018]
Further, if the pressure inside the vacuum suction constant pressure chamber of the vacuum evaporation apparatus fluctuates, when the charge of the web sheet is removed by a glow discharge plasma type static eliminator, the pressure is outside the pressure range where the glow discharge plasma is stably excited. It has also been pointed out that the effect is unstable.
[0019]
[Problems to be solved by the invention]
As described above, when an evaporation material of an insulating metal oxide such as silicon oxide or alumina is deposited on the web sheet by a winding type electron beam vacuum evaporation method, the web sheet is released from the insulating evaporation material 2. Due to the incidence of secondary electrons, a negative charge is charged on the web sheet. These are proposed by Japanese Patent Laid-Open Nos. 05-86470, 07-150355, etc., and damage to the deposited film due to peeling discharge caused by charging of secondary electrons when the web sheet is peeled off from the deposition drum.・ The problem that caused destruction was solved.
[0020]
However, even with these methods, the secondary electrons emitted from the evaporated substance cannot be completely removed from the web sheet, and the negative charge of the secondary electrons that remain charged on the web sheet is immediately before being wound up by the rewinder. Winding tension causes slip friction between the front and back of the web sheet, abnormal discharge occurs with the energy, the front and back of the web sheet are melted, and the web sheets are welded (blocked) to damage or break the deposited film. A new problem has been pointed out.
[0021]
Further, if the pressure inside the vacuum suction constant pressure chamber of the vacuum evaporation apparatus fluctuates, when the charge of the web sheet is removed by a glow discharge plasma type static eliminator, the pressure is outside the pressure range where the glow discharge plasma is stably excited. It has also been pointed out that the effect is unstable.
[0022]
The present invention has been made to solve the above problems, the invention is a web sheet comprising a plastic film which is continuously fed from unwinder, vacuum suction pressure according to claim 1 of the present invention An insulating material that runs on a predetermined running line installed in a room and winds it up with a rewinder, and transpirations by irradiating an electron beam on a vapor deposition drum in a vacuum deposition chamber arranged in the middle of the running line. In a take-up electron beam vacuum deposition apparatus configured to continuously deposit vapor of an evaporating substance on the web sheet, the negative of the web sheet due to incidence of secondary electrons emitted by the evaporating substance It said web Sea cathode glow discharge plasma type static eliminator using a DC power source for removing charge of charge placed immediately before the rewinder was deposited And said parallel cathode neutralization apparatus and caused to travel between the ground counter electrode, a take-up electron beam vacuum vapor deposition apparatus, and removing the charge of negative charge of the web sheet.
[0023]
In the invention according to claim 2 of the present invention, in the take-up electron beam vacuum deposition apparatus 14 according to claim 1, by constantly maintaining the pressure inside the constant pressure chamber 15 by supplying the inert gas 13, It is a winding type electron beam vacuum deposition apparatus characterized by stabilizing the static elimination effect of the web sheet 2.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the take-up electron beam vacuum deposition apparatus of the present invention will be described in detail below.
[0026]
FIG. 1 is an overall schematic view of a winding type electron beam vacuum deposition apparatus according to the present invention. In FIG. 1, the door of the vacuum vapor deposition device 14 is opened, a web sheet 2 made of a roll-shaped plastic film is set on an unwinder (unwinding device) 1, and an unwinder 1 disposed between the unwinder 1 and the vapor deposition drum 4. It travels to the vapor deposition drum 4 through the guide roll 3 on the winder side, and further to the rewinder (winding device) through the guide roll 5 on the rewinder side arranged between the rewinder (winding device) 6. Winding up and completing the preparation for vapor deposition of the web sheet.
[0027]
Next, the door of the vacuum deposition apparatus 14 is closed, and the vacuum pump 14 is connected to the vacuum pump connection port 17 of the vacuum suction constant pressure chamber 15 by the vacuum pump connection port 18 of the vacuum deposition chamber 16. The vacuum suction constant pressure chamber 15 and the vacuum deposition chamber 16 are set to a predetermined vacuum environment. The web sheet 2 is unwound from the unwinder 1, and the evaporated material 7 is heated by the electron beam 20 from the evaporation source 8 disposed below the vapor deposition drum 4 via the guide roll 3, and evaporated to evaporate the web sheet. Vapor deposition. Since the vapor deposition drum 4 is cooled, the vaporized substance 7 is recrystallized and fixed to the web sheet 2. Further, the web sheet 2 deposited through the guide roll 5 on the rewinder side is wound around the rewinder 6.
[0028]
The internal structure of the take-up vacuum deposition apparatus 14 is divided into a vacuum suction constant pressure chamber 15 and a vacuum deposition chamber 16 by a partition wall 9. In addition to the unwinder 1, the guide roll 3, a part of the vapor deposition drum 4, the static eliminator 10, the rewinder 6, the vacuum suction constant pressure chamber 15 includes a tension controller, a speed controller, a position controller, and the like as a control system. . In the vacuum vapor deposition chamber 16, a part of the vapor deposition drum, the evaporation source 8, an electron beam irradiation device, and the like are arranged. The vacuum suction constant pressure chamber 15 is set to a vacuum degree of about 1 × 10 ⁰ MPa and the vacuum deposition chamber 16 is set to about 1 × 10 ⁻² MPa by a vacuum pump arranged around the vacuum deposition apparatus 14. . Since the two chambers are divided by the partition wall 9, impurities such as gas generated from the web sheet 2 in a vacuum environment, and adverse effects during vapor deposition in the vacuum vapor deposition chamber 16 are rare. On the contrary, the radiant heat from the evaporation source 8 disposed in the vacuum deposition chamber 16 has little influence on the vacuum suction constant pressure chamber 15, and therefore has little influence on the web sheet 2.
[0029]
The take-up electron beam vacuum deposition method is a method in which the evaporating substance 7 is directly irradiated with the electron beam 20 to heat and evaporate. In particular, the evaporating substance 7 is used for vacuum deposition of an insulating metal oxide such as silicon oxide or alumina. Is optimal. The electron beam 20 is a heat source for heating the surface of the evaporating substance 7, scans the surface of the evaporating substance 7, converts energy in the portion hit by the electron beam 20, and evaporates the evaporating substance 7. The greatest feature of the electron beam 20 is that not only a high melting point metal but also an evaporant 7 made of an insulating metal oxide such as silicon oxide or alumina can be deposited.
[0030]
Conventionally, when the evaporated substance 7 is a conductor such as a simple metal, the glow discharge plasma treatment of the web sheet 2 performed for the purpose of improving the adhesion of the deposited film was also effective in removing the charge. However, in the case of the evaporating substance 7 such as silicon oxide or alumina having the insulating property, the amount of secondary electrons emitted from the evaporating substance 7 is increased when the evaporating substance 7 is irradiated with the electron beam 20. Since it occurs frequently and is incident on the web sheet 2, the charge cannot be completely removed only by the pretreatment of the glow discharge plasma. Various solutions have been proposed, and 2 when the web sheet 2 is peeled off from the vapor deposition drum. The problem of damage and destruction of the deposited film due to peeling discharge caused by secondary electron charging was solved.
[0031]
However, the removal of the negative charge of the secondary electrons charged on the web sheet 2 is not complete, and the web sheet 2 causes slip friction between the front and back of the web sheet 2 due to the winding tension just before being wound on the rewinder 6. Then, abnormal discharge occurred, the front and back surfaces of the web sheet 2 were melted, and the web sheets 2 were welded (blocked) to cause damage and destruction of the deposited film.
[0032]
Therefore, as a result of examining various solutions, it is optimal that the static eliminator 10 for removing the negative charge of secondary electrons remaining on the web sheet 2 is disposed immediately before the rewinder 6 that winds up the web sheet 2. It turned out to be.
[0033]
Furthermore, it has been pointed out that when the pressure inside the vacuum suction constant pressure chamber 15 of the wind-up type vacuum deposition apparatus 14 fluctuates, the glow discharge plasma is outside the pressure range where it is stably excited, and the static elimination effect is unstable.
[0034]
Therefore, an argon gas supply device including a vacuum gauge 11 and an argon gas flow rate control device 12 is arranged around the take-up type electron beam vacuum vapor deposition device 14, and the argon gas is automatically supplied as appropriate. It has also been found that if the pressure inside the vacuum suction constant pressure chamber 15 is kept constant at all times, the effect of neutralizing the charge of the web sheet 2 by the static eliminator 10 is stabilized.
[0035]
FIG. 2 is a schematic sectional view of a cathode glow discharge plasma type static eliminator 10 in which the electrode on which the web sheet 2 in FIG. 1 travels is a parallel plate type.
[0036]
In FIG. 2, 10a indicates a DC power source, 10b indicates a cathode, and 10c indicates a grounding counter electrode. Here, the cathode 10b and the grounding counter electrode 10c are parallel plate types as shown in the figure.
[0037]
【Example】
An embodiment of the above invention will be described below with reference to FIGS.
[0038]
<Example 1>
As shown in FIG. 1, the door of the vacuum vapor deposition device 14 is opened, the roll-shaped web sheet 2 is set in an unwinder (unwinding device) 1, and an unwinder disposed between the unwinder 1 and the vapor deposition drum 4. The rewinder (winding device) 6 is caused to travel to the vapor deposition drum 4 through the winder side guide roll 3 and further through the rewinder side guide roll 5 disposed between the rewinder (winding device) 6. The web sheet 2 is prepared for vapor deposition.
[0039]
Next, as the evaporating substance 7, silicon oxide (SiO ₂ ) [alumina (Al ₂ O ₃ ), zinc oxide (ZnO), oxide of calcium oxide (CaO), barium oxide (BaO), etc. can also be used]. The evaporation source 8 was set.
[0040]
Next, the door of the vacuum deposition apparatus 14 is closed, and the vacuum pump 14 is connected to the vacuum pump connection port 17 of the vacuum suction constant pressure chamber 15 by the vacuum pump connection port 18 of the vacuum deposition chamber 16. The vacuum suction constant pressure chamber 15 was evacuated until the degree of vacuum was about 1 × 10 ⁰ MPa and the vacuum deposition chamber 16 was about 1 × 10 ⁻² MPa.
[0041]
Next, argon gas was automatically and appropriately supplied into the vacuum suction constant pressure chamber 15 of the vacuum vapor deposition device 14 from the argon gas supply device including the vacuum gauge 11 and the argon gas flow rate control device 12. Since the pressure inside the vacuum suction constant pressure chamber 15 of the vacuum vapor deposition device 14 was always kept constant, the static elimination effect of the static elimination device 10 was also stabilized.
[0042]
Next, the DC power source 10A of the static eliminator 10 was turned on and operated to generate glow discharge plasma in the static eliminator 10.
[0043]
Next, the web sheet 2 is unwound from the unwinder 1, travels through the guide roll 3, and irradiates the electron beam 20 on the vapor deposition drum 4 to continuously apply silicon oxide (SiO ₂ ) onto the web sheet 2. Vapor deposited. Further, the web sheet 2 deposited through the guide roll 5 on the rewinder side is incident on the web sheet 2 during the deposition by passing through the static eliminator 10 generating a stable glow discharge plasma. The negative charge of secondary electrons was neutralized by cations generated by glow discharge plasma. As a result, the web sheet 2 was wound around the rewinder 6 without causing abnormal discharge due to the charge generated immediately before being wound around the rewinder 6 and without causing damage or destruction of the deposited film.
[0044]
<Comparative example 1>
As a comparative example, vapor deposition was performed in the same manner as in Example 1 without operating the static eliminator 10. As a result, the negative charge of the secondary electrons was not neutralized and was wound immediately before being taken up by the rewinder 6. Due to the tension, the front and back sides of the web sheet 2 cause slip friction, and abnormal energy is generated by the energy, the front and back sides of the web sheet 2 are melted, and the web sheets 2 are welded (blocked) to form a deposited film. It has been damaged or destroyed.
[0045]
【The invention's effect】
According to the present invention, when an evaporating substance such as an insulating metal oxide film is formed in a roll-up electron beam vacuum deposition apparatus for the purpose of imparting characteristics that cannot be achieved by a single unit such as a plastic film, it is released from the evaporating substance. Secondary electrons bring negative charge to the web sheet such as plastic film, cause abnormal discharge just before being wound up by a rewinder (winding device), melt the front and back of the web sheet, and the web sheets are welded together (Blocking) It is possible to solve the problem of causing damage or destruction of the deposited film and provide a uniform and high quality deposited film.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a take-up electron beam vacuum deposition apparatus according to the present invention.
FIG. 2 is a sectional view showing a schematic configuration example of a cathode glow discharge plasma type static eliminator according to the present invention.
[Explanation of symbols]
1. Unwinder (unwinding device)
2 ... Web sheet of plastic film 3 ... Unwinder side guide roll 4 ... Deposition drum 5 ... Rewinder side guide roll 6 ... Rewinder (winding device)
7 ... Evaporation substance 8 ... Evaporation source 9 ... Partition of vacuum suction constant pressure chamber and vacuum deposition chamber 10 ... Cathode glow discharge plasma type static eliminator 10a ... DC power supply 10b ... Cathode 10c ··· Grounding counter electrode 11 ··· Vacuum gauge 12 ··· Argon gas flow control device 13 ··· Argon gas supply port 14 ··· Vacuum deposition device 15 ··· Vacuum suction constant pressure chamber 16 ··· Vacuum deposition chamber 17 ... Vacuum pump connection port 18 for vacuum suction constant pressure chamber ... Vacuum pump connection port 19 for vacuum deposition chamber ... Electron beam radiation device connection port 20 ... Electron beam

Claims (2)

The web sheet comprising a plastic film fed from the unwinder continuously, vacuum deposition by traveling in the installed predetermined traveling line to the vacuum suction pressure chamber with wound at the rewinder, is arranged in the middle of the running line In a roll-up electron beam vacuum deposition apparatus configured to continuously deposit vapor of an evaporating substance made of an insulating material that evaporates by irradiating an electron beam on a vapor deposition drum in a chamber. A cathode glow discharge plasma type static eliminator using a DC power source that removes the negative charge of the web sheet caused by the incidence of secondary electrons emitted from the evaporating substance is disposed immediately before the rewinder, and is deposited. A web sheet is run between a parallel cathode and a grounded counter electrode of the static eliminator, and the negative charge band of the web sheet is obtained. Retractable electron beam vacuum vapor deposition apparatus, and removing the.   The roll-up electron beam vacuum deposition apparatus according to claim 1, wherein the neutralization effect of the web sheet is stabilized by constantly maintaining the pressure in the vacuum suction constant pressure chamber by supplying an inert gas. A take-up electron beam vacuum deposition apparatus.

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