JP2008291309A - Vacuum film-forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus having a means of stably depositing a sublimated material on a synthetic resin film so as to improve characteristics of a sublimated material film to be formed on the synthetic resin film. <P>SOLUTION: This film-forming apparatus makes a microwave-generating means preliminarily and uniformly heat a sublimating material. The sublimating material to be irradiated with an electron beam emitted from an electron beam generating means has an approximately smooth surface. A material container is movable. The film-forming apparatus has a mesh-shaped filter made from a refractory material provided in between the material container and a cooling roller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vacuum film forming apparatus for forming a sublimation material on a synthetic resin film. In particular, the sublimation material is stably sublimated by heating the sublimation material preliminarily and uniformly using a microwave generating means.

  In recent years, the use of transparent films made of synthetic resins for food packaging applications has been gradually increasing. This transparent film is mainly made of a flexible polymer resin material, but has a drawback that it allows permeation of scent, water and oxygen. In order to prevent such permeation, aluminum foil or aluminum deposited on a synthetic resin film is mainly used. However, they have the disadvantage that disposal and content status management are relatively difficult. Also, because microwaves do not pass through, in developed countries where microwave ovens are used in almost all households, it is difficult to use as food packaging applications, and the microwave permeability of food packaging materials is often extremely high. It becomes important.

  In order to combine the advantages of a synthetic resin film having microwave permeability with the advantages of an aluminum foil that does not allow water and oxygen to pass through, a metal oxide such as silicon oxide or aluminum oxide is deposited on the synthetic resin film. It is used.

  In a deposition apparatus for depositing these metal oxides on a synthetic resin film, for example, when depositing a silicon oxide film, the deposition material is heated, and the evaporated silicon oxide vapor is oxidized in a controlled reactive atmosphere, It reaches SiOx (x = degree of oxidation of 1.5 to 1.9) on the synthetic resin film. At this time, it is necessary to form silicon oxide on the synthetic resin film at a speed of several meters per second from the viewpoint of economic cost, and a crucible that can withstand the evaporation temperature of silicon oxide of 1,350 ° C. or higher is required. Become.

  However, in a vapor deposition apparatus for depositing a metal oxide on a synthetic resin film, a case where a sublimation material that sublimates directly from a solid such as silicon monoxide and evaporates without passing through a liquid phase is used, and a case such as silicon dioxide. The problem in the apparatus to be used differs greatly from the case of using an evaporating material in which a solid evaporates (melts) through a liquid phase.

  That is, in order to stably form a vapor deposition film of silicon monoxide as a sublimation material, in the process of sublimation of the sublimation material by electron beam irradiation, impurities such as moisture mixed in the sublimation material itself, sublimation material A phenomenon (splash) may occur in which the sublimation material bumps and scatters in a solid phase depending on the surface state or the like.

  Patent Document 1 discloses a method in which a wool-like partition wall is placed on a fixed deposition crucible and no damage is caused directly on the deposition target even when splash occurs. As a result, there is a problem that the original deposition rate is significantly reduced, and there is no example of applying this to a winding deposition system that requires high-speed film formation, a drastic reduction in splash amount, A solution has not yet been invented.

Japanese Unexamined Patent Publication No. 63-24681

  It is an object of the present invention to provide an apparatus having means for stably attaching a sublimated material to a synthetic resin film in order to improve the properties of the sublimated material film formed on the synthetic resin film. .

The invention according to claim 1 is a vacuum film forming apparatus for forming a sublimation material that has been sublimated on at least one surface of a synthetic resin film in a vacuum chamber in a vacuum atmosphere.
The vacuum chamber includes at least a vacuum pump for exhausting air in the vacuum chamber;
An unwinding roll for unwinding the synthetic resin film;
A cooling roll for conveying the synthetic resin film unwound using the unwinding roll;
A winding roll for winding the synthetic resin film conveyed using the cooling roll;
A sublimation material disposed at a position facing the cooling roll;
A material container comprising the sublimation material;
An electron beam generating means for irradiating the sublimation material with an electron beam;
Microwave generation means for irradiating a microwave from an opening of a waveguide to an irradiation portion of a sublimation material irradiated with an electron beam using the electron beam generation means and its peripheral portion;
Gas injection means for injecting gas from a gas pipe disposed near the opening of the waveguide;
It is a vacuum film-forming apparatus characterized by having.

  The invention described in claim 2 is the vacuum film forming apparatus according to claim 1, wherein the surface of the sublimation material is substantially smooth and the material container is movable.

  A third aspect of the present invention is the vacuum film forming apparatus according to the first or second aspect, further comprising a mesh-like filter made of a high melting point material between the material container and the cooling roll.

According to a fourth aspect of the present invention, the microwave generating means includes an oscillator that generates at least a microwave, a matching unit that adjusts the impedance of the microwave, a waveguide that propagates the microwave, and the waveguide. A dielectric that is installed near the opening of the tube, separates the waveguide and the vacuum chamber, and transmits the microwave;
The gas injection means has a length at least ¼ times the wavelength (λ) of the microwave, is closer to the vacuum chamber than the dielectric, and is an electric force through which the microwave propagates inside the waveguide A gas pipe arranged at a position not crossing the line, a gas injection port arranged at a position 1/2 times the wavelength (λ) of the microwave from the dielectric, and a cooling installed at the tip of the gas pipe Means, a permanent magnet installed at the tip of the gas pipe,
The vacuum film forming apparatus according to claim 1, comprising:

  The invention according to claim 5 is the vacuum film forming apparatus according to any one of claims 1 to 4, wherein the sublimation material is silicon monoxide.

  In the present invention, a sublimation material sublimated on a synthetic resin film can be stably formed, and the properties of the sublimation material film to be formed can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a vacuum film forming apparatus according to the present invention.
A vacuum film forming apparatus 1 according to the present invention is configured by separating a vacuum chamber 1a into two regions (region A and region B) by a partition wall 3, and using the vacuum pumps 2a and 2b, the spaces A, Air in region B is exhausted separately.

  Inside the vacuum chamber 1a, the synthetic resin film 7 is unwound using the unwinding roll 5 disposed in the region A, and the synthetic resin film 7 is formed using the cooling roll 4 disposed over the region A and the region B. The synthetic resin film 7 is wound up by using the take-up roll 6 that is transported and disposed in the region A, so that the synthetic resin film 7 forms a pass line that can be transported in vacuum.

  In the region B, using a material container 9 provided with a sublimation material 9 a, an electron beam generation means 8 for irradiating the sublimation material 9 a with an electron beam 8 a, and an electron beam generation means 8. Microwave generation means 12 for irradiating the microwave 12a from the opening of the waveguide 21 and the vicinity of the opening of the waveguide 21 are arranged on the irradiation portion of the sublimation material 9a irradiated with the electron beam 8a and its peripheral portion. Gas injection means 13 for injecting gas from the gas pipe 24 is provided. Although not shown here, the waveguide 21 of the microwave generating means 12 has a shape bifurcated in the width direction of the synthetic resin film 7, and is synthesized from the openings of the two waveguides 21. A microwave 12 a is irradiated on the resin film 7.

  The material container 9 is provided with a material container moving means 11 for moving the material container 9, and a mesh-like filter 10 made of tungsten is installed between the material container 9 and the cooling roll 4. Furthermore, a shutter 13 for protecting the synthetic resin film 7 from radiant heat generated after the apparatus is stopped is installed. Moreover, the code | symbol 9b in a figure represents the sublimation material which sublimated.

The vacuum chamber 1a in the present invention may be in a sealed shape so that a vacuum atmosphere can be maintained when the air in the vacuum chamber 1a is exhausted, and the shape and material are not limited. 1 shows the vacuum chamber 1a separated into two regions by the partition wall 3, the partition wall 3 is not essential. However, by separating the vacuum chamber 1a into the region A and the region B by the partition 3, the degree of vacuum suitable for each process (for example, the region A is a vacuum degree of 1 to 10 ⁻¹ Pa using a roots pump, and the region B is This is preferable because a vacuum of about 10 ⁻³ Pa can be created by the diffusion pump. Furthermore, since it is not necessary to reduce the entire area in the vacuum chamber 1a to a vacuum atmosphere, the film forming conditions can be adjusted efficiently.

  As the vacuum pumps 2a and 2b in the present invention, a roots pump, a diffusion pump, a rotary pump, a turbo molecular pump, a cryopump, a getter ion pump, or the like can be used, but is not limited thereto. Moreover, there is no restriction | limiting in the number to install, What can be adjusted to arbitrary vacuum degrees may be sufficient.

  The unwinding roll 5 and the winding roll 6 in the present invention are not limited in diameter and material, but those having heat resistance on the roll surface such as polyether naphthalate (PEN) and polyether sulfone (PES). preferable. Moreover, it is preferable that the conveyance speed of the synthetic resin film 7 can be adjusted arbitrarily, and it is preferable to have a rotation speed control function capable of controlling individual rotation speeds.

The cooling roll 4 in the present invention is disposed at a position facing the material container 9, and forms a sublimation material 9b sublimated while conveying the synthetic resin film 7 on the synthetic resin film 7. Although there is no restriction | limiting, what performed the chrome plating process to stainless steel or an iron material is preferable. Furthermore, in order to prevent the synthetic resin film 7 from being dissolved by radiant heat from the heated sublimation material, it is preferable to have a cooling function.
As the cooling means, a water cooling means in which cooling water is circulated, a refrigerant made of an antifreeze liquid, or the like can be used, but it is not limited to these.

  The material container 9 in the present invention may be a crucible made of metal such as copper having a cooling mechanism, but is not limited thereto. However, it is preferable that the inside of the material container 9 is smooth so that the surface of the sublimation material 9a contained in the material container 9 is smooth.

  In order to prevent the sublimated material 9b and other materials scattered by the splash from adhering to the inner wall of the vacuum chamber 1a, the vacuum chamber 1a is protected by an adhesion-preventing plate (not shown). Is preferred.

  The electron beam generating means 8 in the present invention can use a thermionic emission type or a field emission type electron gun, but is not limited to these. However, a thermionic emission type is preferable as an electron emission method capable of flowing a large current.

FIG. 2 is a schematic cross-sectional view of the microwave generator 12 shown in FIG.
The microwave generating means 12 in the present invention includes an oscillator 23 that generates a microwave, a matching unit 22 that adjusts the impedance of the microwave, a waveguide 21 that propagates the microwave, and the vicinity of the opening of the waveguide 21. And a dielectric 20 that separates the waveguide 21 and the vacuum chamber 1a and transmits microwaves. Further, the microwave generation means 12 shown in FIG. 1 includes a two-branch waveguide 25 called a magic T for branching the microwave so as not to give a heat distribution in the width direction of the synthetic resin film 7. The synthetic resin film 7 is irradiated with microwaves from the waveguide 21. Moreover, the code | symbol 12a in a figure represents the microwave.

  The oscillator 23 in the present invention is used for generating a microwave, and a general microwave tube represented by a magnetron can be used. Moreover, in this invention, 2.45 GHz which is an industrial allocation frequency is used.

  The matching unit 22 in the present invention can use an E-H tuner capable of adjusting the phase of an electric field and a magnetic field, a stub tuner, a 4E-tuner, or the like. The matching unit 22 used here can adjust the impedance of the microwave.

  The shape of the waveguide 21 in the present invention is determined according to the oscillation frequency, and various modes can be selected depending on the traveling direction of the electromagnetic wave. In the present invention, a fundamental mode of TE wave (Transverse Electric Wave) is used, and EIAJ (model name: WRJ-2) is selected as the waveguide 21, and the shape of the waveguide 21 is a square pole. The size is 100 mm to 200 mm in length and the size of the rectangular opening is 60.75 mm × 109.22 mm. The waveguide 21 used here is capable of propagating microwaves.

  The dielectric 20 in the present invention separates the waveguide 21 and the vacuum chamber 1a, obtains a pressure difference between the waveguide 21 and the vacuum chamber 1a, and the sublimated material adheres to the inside of the waveguide 21. It is used to prevent this, and it is an essential condition that microwaves easily pass through and that it does not deform even if there is a pressure difference. Examples of the material used include quartz glass, which is a high-melting-point material that transmits microwaves and has a low risk of melting even when heated, but is not limited thereto.

Although not shown in FIG. 2, a pressure between the dielectric 20 and the matching unit 22 is set by directly installing a complex molecular pump in the waveguide 21 so that plasma does not occur in the waveguide 20. Is preferably about 10 ⁻³ Pa.

  The microwave generating means 12 in the present invention is used for uniformly heating and removing in advance polar molecules such as moisture contained in the sublimation material 9a including silicon monoxide by irradiating with microwaves. . Further, in order to form a deposited film having excellent film characteristics on the synthetic resin film 7 by ionizing or exciting the material sublimated by the electron beam irradiation by the plasma using the energy by the microwave irradiation. It is used for.

FIG. 3 is a schematic sectional view of the gas injection means 13 shown in FIGS. 1 and 2.
The gas injection means 13 in the present invention includes a gas pipe 24 installed closer to the vacuum chamber 1 a than the dielectric 20, a permanent magnet 241 installed at the tip of the gas pipe 24, and a cooling installed at the tip of the gas pipe 24. The unit 242, the gas injection port 243 installed at the tip of the gas pipe 24, a gas cylinder (not shown), a pressure regulator, and the like are included.

  By using the microwave generation unit 12 and the gas injection unit 13 in the present invention and irradiating the injected gas with microwaves, the gas is excited and ionized, and plasma can be generated around the gas injection port 243.

Generally, microwave energy is easy to radiate and it is difficult to concentrate the microwave energy. However, plasma can be efficiently generated by using the gas pipe 24 of the present invention as an antenna for concentrating the electric field inside the waveguide 21 that propagates microwaves, that is, for concentrating microwave energy. Can do. The gas pipe 24 according to the present invention can generate plasma concentrating only around the gas injection port 243 by injecting gas from the gas injection port 243, and is less affected by the pressure environment in the vacuum chamber 1a. It is.
However, in order to maintain the plasma more stably and stably supply the microwave energy into the plasma, it is necessary to configure a circuit that does not cause a significant fluctuation in the impedance on the load side.

  As the gas pipe 24 in the present invention, a cylindrical shape or a shape with a narrowed tip is preferable. The length of the gas pipe 24 is preferably 1/4 times the wavelength λ of the microwave. Examples of the material for the gas pipe 24 include, but are not limited to, copper, iron, stainless steel, and the like.

  FIG. 4 is a schematic cross-sectional view showing the positional relationship of the gas injection means 13 shown in FIGS. 1 and 2.

  In the present invention, the gas pipe 24 is preferably disposed inside the waveguide 21 that propagates the microwave without energy attenuation and does not cross the electric field lines (in the case of the TE01 mode, it is guided). This is the center position of the long side direction of the tube 21.) In particular, the gas pipe 24 has a length that is ¼ times the wavelength (λ) of the microwave, and the gas injection port 243 is located at a position that is ½ times the wavelength (λ) of the microwave from the wall surface of the dielectric 20. It is preferable that they are arranged.

  Microwave in the vertical vacuum chamber 1a direction from the dielectric 20 surface to 1/2 times the wavelength (λ) of the microwave (+ 2λn times: n is an integer), from the inner wall surface of the waveguide 21 to the inward direction of the vertical waveguide 21 Since the electric field energy is concentrated at a position that is 1/4 times the wavelength of the wave (λ), by providing the gas injection port 243 at this position and radiating the gas, the energy of the microwave can be efficiently obtained. If the pressure around the gas injection port 243 is a pressure region in which discharge is easily excited, jet-like high-density plasma can be easily formed in a narrow space.

In general, the vapor pressure of the sublimation material 9a sublimated in the space between the material container 9 and the synthetic resin film 7 is about 10 ⁻³ to 10 ⁻² Pa in the vicinity of 1,100 ° C., The pressure zone around the gas injection port 243 capable of stably supplying plasma is about 10 ⁻¹ Pa. Thus, although not shown, it is preferable to install a mass flow meter in the gas injection means 13 and maintain the pressure around the gas injection port in an arbitrary pressure band.

By installing the permanent magnet 241 at the tip of the gas pipe 24 in the present invention, electrons are captured around the permanent magnet 241, so that plasma can be stably supplied even at a low gas flow rate. Further, the pressure band around the gas injection port 243 suitable for stable plasma supply is about 10 ⁻¹ Pa, but the pressure band around the gas injection port 243 is about 10 ⁻³ Pa (the formation of a stable sublimate). Even if the pressure zone suitable for the film fluctuates to about 10 ⁻³ Pa), it is possible to stably generate plasma by installing the permanent magnet 241.
As a material used for the permanent magnet 241, a samarium-cobalt alloy system, an iron-nickel-boron alloy system, or the like can be used, but is not limited thereto.

  Furthermore, by installing the cooling means 242 at the tip of the gas pipe 24 according to the present invention, it is possible to prevent the gas pipe 24 from being deformed by heat caused by plasma. As the cooling means, water cooling means or the like obtained by circulating cooling water can be used, but it is not limited to these.

  As gas used for the gas injection means 13 in this invention, gas, such as oxygen, argon, nitrogen, can be used, However, It is not limited to these.

In the vacuum film forming apparatus 1 of the present invention, it is preferable to provide a mesh-like filter 10 between the material container 9 and the cooling roll 4 as shown in FIG.
In the present invention, by using the microwave generating means 12 to irradiate the sublimation material 9a with microwaves and heating it uniformly, impurities mixed in the sublimation material 9a can be evaporated. However, it is difficult to remove all the impurities mixed in the sublimation material 9a in advance, and a splash generated due to the impurities mixed in the sublimation material 9a is installed between the material container 9 and the cooling roll 4. Further trapping can be prevented by trapping with the mesh-shaped filter 10.

  The filter 10 in the present invention can use a high melting point material, and is made of a material such as tungsten or titanium. The mesh shape is a mesh shape, and the aperture is about 1 mm to 10 mm.

  Here, the sublimation material 9a disposed in the material container 9 is a compound that sublimates under vacuum conditions such as silicon monoxide and magnesium fluoride. However, it is not limited to these. Moreover, when forming a laminated body using the vacuum film-forming apparatus of this invention, it is preferable to use silicon monoxide for the sublimation material 9a. When this laminate is used for a gas barrier, silicon monoxide is chemically stable and has a characteristic that it is difficult to corrode even with water. Therefore, a laminate with excellent barrier properties can be obtained. Because.

  The shape and number of the sublimation material 9a are not particularly limited, but the sublimation amount (g / min) of the sublimation material 9a can be stabilized, and the scattering direction of the sublimation material 9a can be made constant. Since it can be maintained, the surface shape of the sublimation material 9a is preferably substantially smooth. When the surface of the sublimation material 9a has an uneven shape, the irradiation angle of the electron beam is not constant, and the scattering direction of the sublimated material 9a becomes irregular.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 5 is a schematic diagram of irradiation with the electron beam and microwave shown in FIG.
The sublimation material 9a used here is a cube obtained by sintering silicon monoxide having a side of 50 mm, and as shown in FIG. 1-No. Up to 49 are arranged. Further, the one surface arranged in a 7 × 7 matrix (No. 1 to No. 49) is arranged in the width direction of the two-surface synthetic resin film 7. Here, one surface is arranged in a 7 × 7 matrix, but this is only one embodiment, and the number of sublimation materials 9a is not limited to this.

  As an irradiation procedure of the electron beam and the microwave in FIG. 5, first, the sublimation material (No. 1) is irradiated with the microwave 12a to remove impurities such as moisture mixed in the sublimation material (No. 1) itself. . Next, the sublimation material (No. 1) is irradiated with the electron beam 8a and the microwave 12a to sublimate the sublimation material (No. 1). At the same time, the sublimation material (No. 2) is irradiated with the microwave 12a to remove impurities such as moisture mixed in the sublimation material (No. 2) itself. Next, the sublimation material (No. 1) is irradiated with the electron beam 8a and the microwave 12a to sublimate the sublimation material (No. 1). At the same time, the microwave 12a is irradiated to the sublimation material (No. 3) to remove impurities such as moisture mixed in the sublimation material (No. 3) itself. These steps are sequentially performed from the sublimation material (No. 1) to the sublimation material (No. 49). Here, the trajectory of the electron beam generating means 8 does not need to be changed at all, and the irradiation position of the electron beam does not always change. Moreover, the irradiation position of the microwave irradiated using the microwave generation means 12 is a range 200a and 200b of 1 square before and after the sublimation material 9a to be sublimated (for 3 squares of No. 10 to No. 12 in FIG. 5). It is preferable that the same space is always irradiated with microwaves while concentrating on. Thereby, the process environment can be stabilized.

  Since the irradiation positions of the electron beam and the microwave irradiated using the electron beam generating means 8 and the microwave generating means 12 are substantially fixed, the material container 9 is moved in the vacuum film forming apparatus shown in FIG. Thus, the irradiation position of the electron beam and the microwave is shifted. The material container 9 can be moved by using a material container moving means 11 (shown in FIG. 1) such as a carriage, but is not limited thereto.

  As shown in FIG. 5, the sublimation of the sublimation material proceeds sequentially from No. 1 to No. 7 by irradiating an electron beam and the material container 9 performs translational mobility at a constant speed in the negative direction of the X axis. Thereafter, in order to further sublimate the sublimation material continuously, the frame moves forward one frame in the negative direction of the Y axis and translates in the opposite (plus) direction in the X axis direction. By repeating these steps, No. 1-No. The sublimation material can be stably sublimated up to 49.

  In FIG. 1-No. No. 10 sublimation material 9a has already been sublimated. No. 11 sublimation material 9a is in a state of being sublimated by electron beam and microwave irradiation. No. 12 sublimation material 9a is in a state where impurities such as moisture mixed in the sublimation material 9a itself are removed by microwave irradiation, No. 12 13-No. 49 shows a state in which neither the electron beam nor the microwave is irradiated.

Further, as shown in FIG. 1, by arranging a mesh-like filter 10 made of a high melting point material in the material container moving means 11, impurities such as inorganic materials that could not be removed by uniform heating by irradiation with microwaves. Splash caused by can be trapped.
Furthermore, since the filter 10 is installed between the sublimation material 9a and the synthetic resin film 7 and irradiates the electron beam and the microwave from the top of the filter 10, the filter 10 is heated and the deposits due to the splash are reduced. be able to. Further, since the filter 10 moves together with the material container 9 and the sublimation material 9a, the mesh state of the filter 10 can always be used as a new one, and there is no need to worry about problems such as clogging.

  Examples of the synthetic resin film 7 used in the present invention include a polyester film made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), a polyolefin film made of polyethylene, polypropylene, etc., a polystyrene film, a polyamide film, A biodegradable plastic film such as a vinyl chloride film, a polycarbonate film, a polyacrylonitrile film, a polyimide film, or a polylactic acid film is used. These films may be either stretched or unstretched, but those having mechanical strength and dimensional stability are preferred. Among these, a polyethylene terephthalate film arbitrarily stretched in a biaxial direction from the viewpoint of heat resistance and dimensional stability is preferably used. Further, the synthetic resin film 7 may be a film containing various additives such as an antistatic agent, an ultraviolet ray preventing agent, a plasticizer, a lubricant, etc., in order to improve the adhesion on the surface on which other layers are laminated. Corona treatment, low temperature plasma treatment, ion bombardment treatment, chemical treatment, solvent treatment and the like may be performed.

  The thickness of the synthetic resin film 7 is not particularly limited. However, in consideration of suitability as a packaging material and suitability for processing when other layers are laminated, the thickness is practically in the range of 3 μm to 200 μm. Furthermore, the thing of about 6 micrometers-30 micrometers is preferable.

<Example 1>
First, a polyethylene terephthalate (PET) film (T60, 25 μm thickness, 500 mm width, 2000 m length, roll winding, manufactured by Toray Industries, Inc.) is installed as a synthetic resin film on a film unwinding roll in a vacuum film forming apparatus, and water-cooled. 200 g of silicon monoxide (manufactured by Sumitomo Titanium Co., Ltd.) was placed as a sublimation material in a copper crucible (material container), and the film formation pressure in the vacuum chamber was evacuated to 3 × 10 ⁻³ Pa by a vacuum pump.

Next, as a microwave generation means, an oscillator for generating a microwave of 2.45 GHz, a matching unit using a 4E tuner, and a dielectric using quartz glass (120 mm × 95 mm × thickness 3 mm) as a waveguide In order to make the pressure inside the waveguide lower than that of the vacuum film forming apparatus, the pressure inside the waveguide was maintained at around 10 ⁻⁴ Pa by the composite molecular pump.
At this time, since the wavelength of 2.45 GHz is about 122 mm (wavelength = wavelength of light / from 2.45 GHz), the gas is located at a position about 60 mm away from the quartz glass (dielectric) and 30 mm away from the inner wall of the waveguide. A gas pipe (having a length of 30 mm) was fixed at the center of the long side of the waveguide so that the injection port was arranged. Furthermore, copper was used as the material of the gas pipe, and water cooling means (cooling means) was installed around the gas pipe, and 1 L / min of cooling water at 25 ° C. was circulated to stabilize the temperature of the gas pipe. A samarium-cobalt alloy permanent magnet was installed at the tip of the gas pipe, and its magnetic force was about 100 gauss.

Next, oxygen plasma is supplied so that the pressure before irradiating the electron beam from the gas injection port becomes 1 × 10 ⁻² Pa, and 2 kW of electric power is supplied from a microwave power source (oscillator), thereby generating oxygen plasma. Was generated.

Next, while heating the temperature of the sublimation material by the electron beam heating means, the PET film was unwound at a running speed of 60 m / min, and vapor deposition on the cooling roll was started. The temperature of the cooling roll at this time is −20 ° C., the moving speed of the material container is 25 mm / min, the acceleration voltage of the electron beam generating means is −40 KV, the emission current value is 0.25 A, and the pressure in the vacuum chamber is 4 ×. 10 ⁻² Pa.

<Comparative Example 1>
Vapor deposition was performed on the PET film in the same manner as in Example 1 except that plasma was generated in the entire vacuum chamber.

<Comparative example 2>
Evaporation was performed on a PET film in the same manner as in Example 1 except that the filter was not placed on the silicon monoxide material.

<Comparative Example 3>
Vapor deposition was performed on the PET film in the same manner as in Example 1 except that the material container moving means was not operated and the electron beam irradiation position was discretely shifted.

<Comparative Example 4>
Evaporation was performed on the PET film in the same manner as in Example 1 except that glass wool was fixed between the PET film and the crucible instead of the filter placed on the material container moving means.

<Evaluation>
Each SiO-attached film prepared using the apparatuses of Example 1 and Comparative Examples 1 to 4 was cut into A4 size. Sample collection points were set at three points of 500 m, 1000 m, and 1500 m in the synthetic resin film transport direction when the film formation start point was 0 m.
First, about each sample, the state of the pinhole around a material container was observed visually.
Next, for each sample, the number of pinholes was observed with an optical microscope.
Next, for each sample, the film thickness of SiO was measured by the fluorescent X-ray reflectivity method.

  The results are shown in Table 1.

In Example 1, it can be seen that the number of pinholes around the material container is small and the amount of splash is small as compared with Comparative Examples 1 to 3.
By comparing Example 1 with Comparative Example 1, it can be seen that the gas, which is an impurity such as moisture due to microwaves, has a correlation with the amount of splash generated from the material itself.
Moreover, by comparing Example 1 with Comparative Example 2, it can be seen that the amount of splash given to the film by the trapping effect of the filter is greatly suppressed.
Further, in Comparative Example 3, since the focal length of the electron beam is changed successively, not only the uniform performance of the film thickness is deteriorated, but also the effect of degassing by microwaves cannot be expected, so the amount of splash is very large. As a result. This shows that the uneven surface state of the sublimation material generated by the electron beam irradiating the surface of the sublimation material heated and sublimated with an electron beam many times has a correlation with the splash amount. .
Further, in Comparative Example 4, it can be seen that the film thickness of SiO tends to become thin due to clogging of the filter with the film formation over a long period of time, and the mass productivity is poor.

1 is a schematic cross-sectional view of a vacuum film forming apparatus in the present invention. The cross-sectional schematic when the microwave generation means shown in FIG. 1 is seen from the upper surface. The cross-sectional schematic of the gas injection means 13 shown in FIG. 1 and FIG. FIG. 3 is a schematic cross-sectional view showing the positional relationship of the gas injection means 13 shown in FIGS. 1 and 2. FIG. 2 is a schematic diagram of an electron beam and microwave irradiation procedure shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum film-forming apparatus 2 Vacuum pump 3 Bulkhead 4 Cooling roll 5 Unwinding roll 6 Winding roll 7 Synthetic resin film 8 Electron beam generating means 8a Electron beam 9 Material container 9a Sublimation material 9b Sublimation material 10 Filter 11 Material container movable Means 12 Microwave generation means 12a Microwave 20 Dielectric 21 Waveguide 22 Matching device 23 Oscillator 24 Gas pipe 25 Two-branch waveguide 200a Microwave irradiation range 200b Microwave irradiation range 241 Permanent magnet 242 Cooling means 243 Gas injection port

Claims (5)

In a vacuum film forming apparatus for forming a sublimated material that has been sublimated on at least one surface of a synthetic resin film in a vacuum chamber under a vacuum atmosphere,
The vacuum chamber includes at least a vacuum pump for exhausting air in the vacuum chamber;
An unwinding roll for unwinding the synthetic resin film;
A cooling roll for conveying the synthetic resin film unwound using the unwinding roll;
A winding roll for winding the synthetic resin film conveyed using the cooling roll;
A sublimation material disposed at a position facing the cooling roll;
A material container comprising the sublimation material;
An electron beam generating means for irradiating the sublimation material with an electron beam;
Microwave generation means for irradiating a microwave from an opening of a waveguide to an irradiation portion of a sublimation material irradiated with an electron beam using the electron beam generation means and its peripheral portion;
Gas injection means for injecting gas from a gas pipe disposed near the opening of the waveguide;
A vacuum film forming apparatus comprising:   2. The vacuum film forming apparatus according to claim 1, wherein the surface of the sublimation material is substantially smooth, and the material container is movable.   The vacuum film-forming apparatus according to claim 1, further comprising a mesh-like filter made of a high melting point material between the material container and the cooling roll. The microwave generating means is installed in the vicinity of an oscillator that generates at least a microwave, a matching unit that adjusts the impedance of the microwave, a waveguide that propagates the microwave, and an opening of the waveguide, A dielectric that separates the waveguide and the vacuum chamber and transmits the microwave; and
The gas injection means has a length at least ¼ times the wavelength (λ) of the microwave, is closer to the vacuum chamber than the dielectric, and is an electric force through which the microwave propagates inside the waveguide A gas pipe arranged at a position not crossing the line, a gas injection port arranged at a position 1/2 times the wavelength (λ) of the microwave from the dielectric, and a cooling installed at the tip of the gas pipe Means, a permanent magnet installed at the tip of the gas pipe,
The vacuum film-forming apparatus according to claim 1, comprising:   The vacuum film-forming apparatus according to claim 1, wherein the sublimation material is silicon monoxide.

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