Film formation device and method for controlling same

Abstract

A film formation device according to one embodiment of the present invention includes a vacuum chamber, a conveyance roller, a vapor deposition source, a monitoring section, and a control section. The conveyance roller is disposed inside the vacuum chamber and supports a film-like base material. The vapor deposition source includes: a vapor deposition boat having a storage section for storing an evaporation material to be vapor-deposited on the base material supported by the conveyance roller; and a material supply section that supplies the evaporation material to the storage section. The evaporation material stored in the storage section is melted by electrical heating of the vapor deposition boat. The monitoring section includes a camera unit that acquires images of the molten evaporation material in the storage section. The control section controls, based on the output of the monitoring section, at least one of: the supply rate or the supply position of the evaporation material in the vapor deposition source to the storage section; and the electrical power supplied to the vapor deposition boat.

Description

Film forming apparatus and control method thereof

[0001] The present invention relates to a winding-type film forming apparatus and a control method thereof.

[0002] Conventionally, a film forming apparatus has been known in which a long raw material film continuously unwound from a winding roller is wound around a cooling roller, a deposition material is deposited on the raw material film from an evaporation source arranged opposite the cooling roller, and the deposited raw material film is then wound up by a take-up roller (see, for example, Patent Document 1).

[0003] Furthermore, as an evaporation source for this type of film forming apparatus, for example, a so-called resistance heating evaporation source is known, which includes an evaporation boat having an accommodation portion for the evaporation material, and a material supply means for supplying wire-shaped evaporation material to the evaporation boat, and which heats the evaporation boat to evaporate the evaporation material into the accommodation portion (see, for example, Patent Document 2).

[0004] Patent No. 3795518 Patent No. 7404582

[0005] In a winding-type film-forming apparatus equipped with a resistance-heating evaporation source, it is necessary to maintain a stable evaporation rate and prevent a decrease in product yield due to splashing (bumping). However, the frequency of splashing varies greatly depending on the melting rate of the evaporation material in the evaporation source and the amount of molten metal, and a technology to effectively suppress splashing has not yet been established.

[0006] In view of the above circumstances, an object of the present invention is to provide a film forming apparatus and a control method thereof that can maintain a stable deposition rate and prevent a decrease in product yield due to splashing.

[0007] A film formation apparatus according to one aspect of the present invention includes a vacuum chamber, a transport roller, a vapor deposition source, a monitoring unit, and a control unit. The transport roller is disposed inside the vacuum chamber and supports a film-like substrate. The vapor deposition source includes a vapor deposition boat having a storage unit that stores an evaporation material to be evaporated onto the substrate supported by the transport roller, and a material supply unit that supplies the evaporation material to the storage unit, and melts the evaporation material stored in the storage unit by applying electrical heat to the vapor deposition boat. The monitoring unit includes a camera unit that captures images of the molten evaporation material in the storage unit. The control unit controls at least one of the supply speed or supply position of the evaporation material to the storage unit in the vapor deposition source and the electrical power applied to the vapor deposition boat, based on the output of the monitoring unit.

[0008] The control unit may be configured to acquire information regarding the area of ​​the molten metal based on the output of the monitoring unit, and to control the evaporation source so that the ratio of the area of ​​the molten metal to the area of ​​the accommodation unit is equal to or greater than a predetermined value.

[0009] The control unit may be configured to obtain information regarding the depth of the molten metal based on the output of the monitoring unit, and to control the evaporation source so that the depth of the molten metal is equal to or less than a predetermined value.

[0010] The control unit may be configured to obtain information regarding the amount of dissolved evaporation material based on the output of the monitoring unit, and to control the deposition source so that the amount of dissolved evaporation material falls within a predetermined range.

[0011] The evaporation material may be a wire-shaped evaporation material.

[0012] The camera unit may include an infrared camera and a visible light camera.

[0013] A control method for a film formation apparatus according to one embodiment of the present invention is a control method for a film formation apparatus including: a vacuum chamber; transport rollers arranged inside the vacuum chamber and supporting a film-shaped substrate; a vapor deposition boat made of a heat-generating material having a storage section that stores an evaporation material to be evaporated onto the substrate supported by the transport rollers; and a vapor deposition source having a material supply section that supplies the evaporation material to the storage section, the vapor deposition boat melting the evaporation material stored in the storage section by applying electrical heat to the evaporation boat, the control method comprising: acquiring a camera image of the molten evaporation material in the storage section; and controlling, based on the camera image, at least one of a supply speed or a supply position of the evaporation material in the vapor deposition source to the storage section and an electrical power applied to the evaporation boat.

[0014] According to the present invention, it is possible to maintain a stable deposition rate and to suppress a decrease in product yield due to splashing.

[0015] 1 is a schematic configuration diagram of a film formation apparatus according to an embodiment of the present invention. FIG. 1 is a schematic perspective view showing the configuration of a vapor deposition source of the film formation apparatus. FIG. 2 is a schematic side cross-sectional view of the vapor deposition source. FIG. 3 is a schematic side cross-sectional view showing an example of the shape of molten metal in a vapor deposition boat. FIG. 4 is a schematic diagram of a vapor deposition source explaining the principle of splash generation in FIG. 5 is a schematic side cross-sectional view showing another example of the shape of molten metal in a vapor deposition boat. FIG. 6 is a schematic diagram of a vapor deposition source explaining the principle of splash generation in FIG. 7 is a simulation result of heat distribution in a vapor deposition boat. FIG. 8 is an experimental result showing the relationship between the area ratio of the molten metal to the evaporation material and the number of splashes. FIG. 9 is an experimental result showing the relationship between the area variation rate of the molten metal, the number of splashes, and the dissolved amount of evaporation material. FIG. 10 is a schematic side cross-sectional view of a vapor deposition boat explaining the supply position of the evaporation material and the supplyability of the evaporation material to the vapor deposition boat. FIG. 11 is a flowchart showing an example of a processing procedure executed in a control unit of the film formation apparatus. FIG. 12 is a schematic side cross-sectional view of a vapor deposition boat explaining a method of calculating the depth of the molten metal in the vapor deposition boat.

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] 1 is a schematic diagram of a film formation apparatus 100 according to one embodiment of the present invention. The film formation apparatus 100 of this embodiment is configured as a roll-to-roll vacuum deposition apparatus.

[0018] [Basic Configuration of Film Forming Apparatus] The film forming apparatus 100 of this embodiment includes a vacuum chamber 10 , a vapor deposition source 20 , a film transport unit 30 , a monitoring unit 40 , and a control unit 50 .

[0019] (Vacuum Chamber) The vacuum chamber 10 is a sealed container made of metal and is connected to a ground potential. The vacuum chamber 10 is connected to an exhaust line 13 having a vacuum pump 11 and a vacuum valve 12. The inside of the vacuum chamber 10 is configured so that it can be evacuated to or maintained at a predetermined reduced pressure atmosphere by this exhaust line 13.

[0020] The vacuum chamber 10 accommodates an evaporation source 20 and a film transport unit 30. A partition plate 14 is provided inside the vacuum chamber 10, and this partition plate 14 divides the inside of the vacuum chamber 10 into a film formation chamber 15 and a transport chamber 16.

[0021] (Vapor deposition source) The vapor deposition source 20 is a film formation unit that heats and vaporizes an evaporation material. Fig. 2 is a schematic perspective view showing the configuration of the vapor deposition source 20, and Fig. 3 is a schematic side cross-sectional view thereof. The vapor deposition source 20 has a vapor deposition boat 21 and a material supply unit 22.

[0022] The evaporation boat 21 is made of a plate of a high-melting-point material that can generate heat to a temperature higher than the melting point of the evaporation material M when current is applied. Examples of the high-melting-point material include ceramic materials such as boron nitride, and metal materials such as molybdenum, tungsten, and tantalum. A plurality of evaporation boats 21 are arranged in the width direction of the film F, with their longitudinal directions facing the transport direction of the film F, for example.

[0023] The evaporation boat 21 has a storage section 21a on its upper surface facing the main roller 33, which stores the evaporation material M and its molten metal Mm. The storage section 21a is a rectangular recess with a depth D formed on the upper surface of the evaporation boat 21. Terminals 21b connected to a power supply circuit 23 are provided on both longitudinal ends of the evaporation boat 21, and the evaporation material stored in the storage section 21a is melted by electrical heating using a current supplied from the power supply circuit 23. The power supply circuit 23 is located outside the vacuum chamber 10, and the power supplied to the evaporation boat 21 is controlled by a control section 50, which will be described later.

[0024] The material supply unit 22 is disposed in the film formation chamber 15 and supplies the evaporation material M to the container of the deposition boat 21. The evaporation material M is formed into a wire-like member having a wire diameter of, for example, about 2 mm. The evaporation material is, but is not limited to, aluminum. Examples of the evaporation material include metal materials such as copper, lithium, tin, and zinc, alloys of these metals, and oxides, nitrides, and fluorides of these metals.

[0025] The material supply unit 22 includes a payout roller 221 that pays out the wire-shaped evaporation material M in the longitudinal direction. The payout roller 221 is configured to be able to pay out the evaporation material M continuously at a predetermined speed or intermittently at a predetermined cycle. The material supply unit 22 is further configured to be able to move horizontally as shown by arrow A in Fig. 3 so as to change the supply position of the evaporation material M relative to the storage unit 21a of the evaporation boat 21. The supply of the evaporation material M by the payout roller 221 and the horizontal movement of the material supply unit 22 are controlled by a control unit 50, which will be described later.

[0026] (Film Conveyance Section) The film conveyance section 30 is disposed in the conveyance chamber 16. The film conveyance section 30 has an unwinding roller 31 that continuously pays out the film F, which is the substrate, a take-up roller 32 that continuously winds up the film F unwound from the unwinding roller 31, and a main roller 33 (conveyance roller) that is installed in the film conveyance path between the unwinding roller 31 and the take-up roller 32. The film conveyance section 30 further has a first auxiliary roller 34 that is disposed upstream of the main roller 33, and a second auxiliary roller 35 that is disposed downstream of the main roller 33.

[0027] The unwinding roller 31, the take-up roller 32, and the main roller 33 each include a rotational drive unit (not shown) and are configured to rotate at a predetermined speed in the direction of the arrows shown in the figure. This allows the film F to be transported at a predetermined transport speed from the unwinding roller 31 to the take-up roller 32 within the vacuum chamber 10. Note that the first auxiliary roller 34 and the second auxiliary roller 35 are each configured as free rollers without a rotational drive unit, but the present invention is not limited to this and each may also include a rotational drive unit.

[0028] At least a portion of the main roller 33 faces the vapor deposition source 20 through an opening 14a provided in the partition plate 14. The film F is transported toward the take-up roller 32 while being wrapped around the outer circumferential surface of the main roller 33 at a predetermined wrap angle, and a film is formed on the surface area exposed to the film formation chamber 15 through the opening 14a by the vapor deposition source 20. The film F is taken up by the take-up roller 32 while a film is continuously formed on the outer circumferential surface of the main roller 33 in the longitudinal direction.

[0029] The film F is an insulator and is made of a resin film such as an OPP (oriented polypropylene) film, a PET (polyethylene terephthalate) film, a PPS (polyphenylene sulfite) film, a PI (polyimide) film, etc. However, the film F is not limited to these, and may be made of a metal film such as a copper film or an aluminum film.

[0030] Since the exhaust line 14 is connected to the film formation chamber 15, a pressure difference occurs between the film formation chamber 15 and the transfer chamber 16 during exhaust due to the presence of the partition wall 14. This pressure difference prevents the vapor flow of the evaporation material from entering the transfer chamber 16 through the opening 14 a.

[0031] Although not shown, a shutter capable of blocking the vapor flow of the evaporation material M from reaching the film F supported on the main roller 33 from the evaporation source 20 may be disposed between the evaporation source 20 (evaporation boat 21) and the main roller 33. For example, by closing the shutter until the evaporation of the evaporation material M in the evaporation source 20 stabilizes, such as at the beginning of film formation, the evaporation material can be evaporated onto the film F at a stable film formation rate.

[0032] (Monitoring Unit) The monitoring unit 40 monitors the state of the evaporation material M supplied to the evaporation boat 21, and includes a camera unit 41 that acquires images of the molten evaporation material in the accommodation portion 21 a of the evaporation boat 21. As shown in Fig. 1 , the camera unit 41 is disposed outside (on the atmospheric side of) the vacuum chamber 10, and is capable of capturing images of the inside of the film formation chamber 15 through a window portion 17 made of a light-transmitting material and provided in a part of the side wall of the vacuum chamber 10.

[0033] In this embodiment, the camera unit 41 includes an infrared camera and a visible light camera. The infrared camera is used to monitor, for example, the area and spread of the molten metal Mm in the deposition boat 21, and the visible light camera is used to monitor, for example, the depth of the molten metal Mm in the deposition boat 21. The image data acquired by the camera unit 41 is output to the control unit 50.

[0034] (Control Unit) The control unit 50 is a controller that controls the overall operation of the film forming apparatus 100, including the exhaust line 13, the vapor deposition source 20, and the film transport unit 30. The control unit 50 is realized by hardware elements used in a computer, such as a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory), as well as necessary software.

[0035] The control unit 50 controls the material supply unit 22 and the power supply circuit 23 based on the output of the monitoring unit 40. More specifically, the control unit 50 has an image processing unit that processes images acquired by the camera unit 41, and a calculation unit that calculates the area ratio and area variation rate of the molten metal of the evaporation material M, or the supply speed and supply position of the evaporation material M, based on the images acquired by the camera unit 41. Note that the image processing unit and calculation unit may be provided in the monitoring unit 40.

[0036] The control unit 50 is configured to control at least one of the supply speed or supply position of the evaporation material M to the storage portion 21 a in the evaporation source 20 and the power supplied to the evaporation boat 21 , the details of which will be described later.

[0037] [Considerations on the occurrence of splashing] In this type of winding-type film-forming apparatus, it is necessary to maintain a stable deposition rate and to prevent a decrease in product yield due to splashing. However, the frequency of splashing varies greatly depending on the melting rate of the deposition material in the deposition source and the amount of molten metal.

[0038] 4 and 5, if the depth d of the molten metal Mm in the accommodation portion 21a of the deposition boat 21 becomes large, gas (bubbles) G generated in the molten metal Mm during heating of the evaporation material M grows larger before reaching the liquid surface of the molten metal Mm, which tends to increase the diameter of droplets (splashes) Ms that fly from the liquid surface of the molten metal Mm toward the film F directly above. As a result, the shape of the splashes Ms that adhere to the deposition surface of the film F becomes larger, which may cause deterioration in the appearance and flatness of the deposition surface. For this reason, it is necessary to adjust the amount of the molten metal Mm so that the depth of the molten metal does not become too large.

[0039] In FIG. 2, the width W is 45 mm, the length L is 150 mm, and the volume of the storage portion 21a is 3900 mm. ３ Aluminum was vapor-deposited onto a film F using a vapor deposition boat sample (hereinafter also referred to as vapor deposition boat 21S), and the number of splashes per unit area exceeding 80 μm in size was measured. The shortest distance between the vapor deposition boat 21S and the film F was 270 mm, and the heating temperature of the vapor deposition boat 21S was 1500°C (power: 28 W). As a result of the experiment, when the depth d of the molten metal was 0.4 mm, the number of splashes per unit area was 62.5 [pieces / m ２ ], whereas when the depth d was 0.2 mm, it was 1.9 [pieces / m ２ From this result, the number of splashes was 10 [pieces / m ２ It has been confirmed that, in the case of

[0045] , the depth d of the molten metal is preferably less than 0.4 mm, more preferably 0.3 mm or less.

[0040] Furthermore, as shown in Figure 6, splashing can also occur when the spread (area) of the molten metal Mm in the accommodation portion 21a of the deposition boat 21 is small. For example, as shown schematically in Figures 7(A) and 7(B), when the spread of the molten metal Mm is small, a large temperature difference is likely to occur in the deposition boat 21 between the region in contact with the molten metal Mm and the region not in contact with it. If a large fluctuation in the amount of the molten metal Mm occurs in this state and the area of ​​the molten metal Mm expands, the molten metal Mm on the low-temperature side is rapidly heated upon contact with the deposition boat 21 on the high-temperature side, making splashing Ms more likely to occur. For this reason, it is necessary to adjust the amount of the molten metal Mm so that the spread of the molten metal Mm does not become too small.

[0041] 8 shows the results of a simulation of the heat distribution in the deposition boat 21S when the area ratio of the molten aluminum to the opening area of ​​the accommodation portion of the deposition port 21S is 0%, 33%, 67%, and 99%. Here, the power was adjusted (power: 28 W) so that the temperature at the center of the deposition boat 21S was 1500°C.

[0042] As shown in Fig. 8, the heat distribution of the evaporation boat 21S alone when there is no molten aluminum is such that the temperature distribution is highest at the center of the boat. On the other hand, when the area ratio of the molten metal is 33%, the temperature distribution is highest at two positions on both sides of the center of the boat in the longitudinal direction, and this can be said to increase the risk of splashing because a temperature difference is likely to occur within the accommodation section of the evaporation boat 21S as shown in Fig. 7(B) . In contrast, when the area ratio of the molten metal is 67% or 99%, it is considered that the temperature difference within the accommodation section can be kept small, thereby reducing the risk of splashing.

[0043] Figure 9 shows the relationship between the aluminum molten metal ratio (area ratio) and the number of splashes [pieces / m ２ Here, the number of splashes exceeding 80 μm in size was counted, and the shortest distance between the deposition boat 21S and the film F was set to 270 mm, the heating temperature of the deposition boat 21S was set to 1500° C. (power: 28 W), the depth d of the molten metal was set to 0.2 mm, and the supply rate of aluminum (evaporation material M) was set to 565 mm / min.

[0044] As shown in FIG. 9, the number of splashes tends to decrease as the area ratio of the molten metal increases. For example, when the area ratio is 60% or more, the number of splashes is reduced to 10 [pieces / m ２ ] and it was confirmed that the temperature can be stably suppressed below this.

[0045] On the other hand, Figure 10 shows the relationship between the area variation rate of the molten metal and the number of splashes [number / m ２ ] and the amount of melted aluminum at the tip of the evaporation material M. Here, the number of splashes exceeding 80 μm in size was counted, and the shortest distance between the evaporation boat 21S and the film F was set to 270 mm, the heating temperature of the evaporation boat 21S to 1500°C (power: 28 W), and the depth d of the molten aluminum to 0.2 mm.

[0046] As shown in FIG. 10, the number of splashes and the amount of aluminum dissolved at the tip tend to increase as the area fluctuation rate of the molten metal increases, and the number of splashes and the amount of aluminum dissolved at the tip tend to increase as the area fluctuation rate of the molten metal increases. ２ In order to keep the number of splashes to 0.07% or less, it is preferable that the area variation rate of the molten metal is 0.07% or less, and in order to achieve such an area variation rate, it is necessary to appropriately adjust the amount of dissolved evaporation material M.

[0047] The amount of melted evaporation material M can be adjusted not only by the supply rate but also by the supply position of the evaporation material M relative to the accommodation portion 21a of the evaporation boat 21. For example, as shown in Figures 11A to 11C, the amount of melted varies depending on whether the position of the tip of the evaporation material M is at the back side (left side in the figure) of the accommodation portion 21a or at the center or front side (right side in the figure), because the region T of the evaporation material M that receives radiant heat from the evaporation boat 21 is different. However, even if the amount of melted is large, the supply efficiency of the molten metal Mm to the accommodation portion 21a is not necessarily high.

[0048] 11(A), when the tip of the evaporation material M is located at the back side of the accommodation section 21a, the area T where the evaporation material M receives radiant heat from the deposition boat 21 becomes large, and the amount of melted evaporation material M per unit time increases, so it seems that the supplyability of the molten metal Mm is high. However, it takes time for the molten metal Mm to spread to every corner of the accommodation section 21a, and furthermore, the molten metal Mm evaporates as it spreads, resulting in a low supplyability of the molten metal Mm.

[0049] On the other hand, when the tip of the evaporation material M is located in the center of the storage section 21a as shown in FIG. 11(B), the molten metal Mm tends to spread to every corner of the storage section 21a, improving the supply efficiency of the molten metal.

[0050] In addition, when the tip of the evaporation material M is located on the front side of the storage section 21a as shown in Figure 11 (C), the area T where the evaporation material M receives radiant heat from the evaporation boat 21 becomes smaller, and the amount of evaporation material dissolved per unit time is small, so the supplyability of the molten metal Mm becomes low.

[0051] Furthermore, a certain correlation is observed between the electric power supplied to the deposition boat 21 and the area ratio of the molten metal Mm, and the area ratio of the molten metal Mm tends to decrease as the electric power increases. This is because as the electric power increases, the amount of melted evaporation material M increases, but at the same time, the amount of evaporated molten metal Mm also increases. For this reason, in order to maintain the target area ratio of the molten metal Mm, it is preferable to keep the electric power applied to the deposition boat 21 at a predetermined level or less.

[0052] [Operation of Film Forming Apparatus] Next, an example of the operation of the film forming apparatus 100 of this embodiment configured as described above will be described. Fig. 12 is a flowchart showing an example of a processing procedure executed by the control unit 50.

[0053] When the operation of the film formation apparatus 100 starts, the control unit 50 executes a film formation pre-processing (ST101). The film formation pre-processing is a preparation step before the film formation process, and typically includes evacuation of the vacuum chamber 10, heating for degassing the deposition boat 21, and closing the shutter. When the film formation pre-processing is completed, the control unit 50 executes adjustment processes for the deposition source 20 (ST102 to 108).

[0054] In the adjustment process of the evaporation source 20, first, the control unit 50 heats the evaporation boat 21 to a temperature (e.g., 1500°C) higher than the melting point of the evaporation material M, and then supplies the evaporation material M from the material supply unit 22 to the evaporation boat 21 (ST102). The supply position of the evaporation material M is not particularly limited, and it is supplied to, for example, the center of the accommodation unit 21a.

[0055] Next, the control unit 50 acquires information about the area of ​​the molten metal Mm based on the output of the monitoring unit 40 (camera unit 41) and determines whether the area ratio of the molten metal Mm to the area of ​​the accommodation section 21a is equal to or greater than a predetermined value (ST103). In this embodiment, the predetermined value of the area ratio is set to 60%. This reduces the risk of splashing (see FIG. 9).

[0056] The area ratio of the molten metal Mm can be calculated using, for example, an image acquired by an infrared camera of the monitoring unit 40. In this case, the area ratio of the molten metal Mm can be calculated by calculating the ratio of the area of ​​the molten metal Mm to the area (opening area) of the accommodation portion 21 a of the evaporation boat 21, which is stored in advance. The algorithm for calculating the area ratio is not particularly limited, and a machine learning machine may be used.

[0057] When the control unit 50 determines that the area ratio of the molten metal Mm is not greater than a predetermined value (No in ST103), it adjusts at least one of the supply position, supply speed, and current power applied to the evaporation boat 21 of the evaporation material M so that the area ratio of the molten metal Mm becomes greater than the predetermined value (ST104).

[0058] Specifically, examples of such methods include changing the supply position of the evaporation material M, increasing the supply speed of the evaporation material M, and lowering the applied electric power. Changing the supply position is also effective when the wettability of the molten metal Mm is poor, and in this case the supply position may be set in an area with poor wettability. Note that the adjustment of the applied electric power may be an adjustment of the current value, an adjustment of the voltage value, or both (the same applies below).

[0059] Next, the control unit 50 acquires information about the depth d of the molten metal Mm based on the output of the monitoring unit 40 (camera unit 41) and determines whether the depth d of the molten metal Mm is equal to or less than a predetermined value (ST105). The predetermined value of the depth d is not particularly limited as long as it is less than 0.4 mm under the conditions described in the above "Consideration of the occurrence of splashing," and in this embodiment it is 0.3 mm or 0.2 mm. This makes it possible to reduce the risk of splashing.

[0060] The depth d of the molten metal Mm can be calculated, for example, using an image acquired by a visible light camera of the monitoring unit 40. In this case, as shown in Figures 13(A) and 13(B), for example, the depth d of the molten metal Mm can be calculated from the difference (D-d0) between the depth D of the accommodation portion 21a of the deposition boat 21 measured in advance and the height d0 from the molten metal surface to the opening edge of the accommodation portion 21a, which is calculated based on an image of the molten metal Mm after formation. The algorithm for calculating the depth d is not particularly limited, and a machine learning machine may also be used in this case.

[0061] When the control unit 50 determines that the depth d of the molten metal Mm is not equal to or less than the predetermined value (No in ST105), it adjusts at least one of the supply rate of the evaporation material M and the electric power applied to the deposition boat 21 so that the depth d of the molten metal Mm is equal to or less than the predetermined value (ST106). Specifically, for example, the control unit 50 may adjust the supply rate of the evaporation material M or the electric power, for example, by decreasing the supply rate of the evaporation material M or increasing the electric power.

[0062] Next, the control unit 50 acquires information about the amount of melted evaporation material M based on the output of the monitoring unit 40, and determines whether the amount of melted evaporation material M is within a predetermined range (ST107). The predetermined range is not particularly limited as long as it is an amount at which the risk of splashing is reduced and the depth d of the molten metal Mm is equal to or less than a predetermined value (e.g., 0.3 mm).

[0063] As a method for calculating the amount of dissolved evaporation material M, for example, an image acquired by a visible light camera of the monitoring unit 40 can be used. In this case, the amount of dissolved evaporation material M can be calculated from the supply amount or supply speed of the evaporation material M supplied from the material supply unit 22. Alternatively, a machine learning machine may also be used in this case.

[0064] Another method for calculating the amount of dissolved evaporative material M is to use, for example, images acquired by an infrared camera of the monitoring unit 40. In this case, the amount of dissolved evaporative material M can be calculated from the amount of fluctuation (or fluctuation rate) per unit time of the area ratio of the molten metal Mm. Under the conditions in the above-mentioned "Study on the occurrence of splashes," the above-mentioned fluctuation rate is preferably, for example, 0.06% or less (see FIG. 10). In this case, a machine learning machine may also be used.

[0065] When the control unit 50 determines that the amount of dissolved evaporation material M is not within the predetermined range (No in ST107), it adjusts at least one of the supply position of the evaporation material M and the electric power applied to the deposition boat 21 so that the amount of dissolved evaporation material M falls within the predetermined range (ST108). Specifically, for example, the control unit 50 may adjust the supply position of the evaporation material M or increase or decrease the electric power.

[0066] When the amount of dissolved evaporation material M is within the predetermined range, the control unit 50 ends the film formation pre-processing and starts the film formation process (ST109). At the start of the film formation process, the film transport unit 30 is driven to transport the film F at a predetermined transport speed, and a shutter (not shown) is opened to deposit evaporated particles of the evaporation material M evaporated in the deposition source 20 onto the film F on the main roller 33.

[0067] After the start of the film formation process, the control unit 50 again executes the processes of ST103 to ST108 described above to control the deposition source 20 (the supply position and supply speed of the evaporation material M, and the energization power) so that the area ratio of the molten metal Mm is equal to or greater than a predetermined value, the depth d of the molten metal Mm is equal to or less than a predetermined value, and the amount of dissolved evaporation material is within a predetermined range (ST110). Such monitoring of the molten metal Mm is repeatedly executed at predetermined time intervals during the film formation process.

[0068] As described above, according to this embodiment, at least one of the supply speed or supply position of the evaporation material M to the storage section 21a in the evaporation source 20 and the power supplied to the evaporation boat 21 is controlled based on the output of the monitoring section 40, thereby maintaining a stable evaporation rate and suppressing a decrease in product yield due to splashing.

[0069] Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and that various modifications can be made.

[0070] REFERENCE SIGNS LIST 10 vacuum chamber 20 evaporation source 21 evaporation boat 21a storage section 22 material supply section 30 film transport section 40 monitoring section 41 camera unit 50 control section M evaporation material Mm molten metal

Claims

1. A film formation apparatus comprising: a vacuum chamber; transport rollers disposed inside the vacuum chamber and supporting a film-like substrate; a vapor deposition boat having a storage section for storing an evaporation material to be evaporated onto the substrate supported by the transport rollers; and a material supply section for supplying the evaporation material to the storage section, the vapor deposition source melting the evaporation material stored in the storage section by applying electrical heat to the vapor deposition boat; a monitoring section including a camera unit for capturing images of the molten evaporation material in the storage section; and a control section for controlling, based on an output from the monitoring section, at least one of the supply speed or supply position of the evaporation material from the vapor deposition source to the storage section and the electrical power applied to the vapor deposition boat.

2. A film forming apparatus according to claim 1, wherein the control unit acquires information relating to the area of ​​the molten metal based on the output of the monitoring unit, and controls the evaporation source so that the ratio of the area of ​​the molten metal to the area of ​​the container unit is equal to or greater than a predetermined value.

3. A film forming apparatus according to claim 1, wherein the control unit acquires information relating to the depth of the molten metal based on the output of the monitoring unit, and controls the evaporation source so that the depth of the molten metal is equal to or less than a predetermined value.

4. A film forming apparatus according to claim 1, wherein the control unit acquires information relating to the amount of dissolved evaporation material based on the output of the monitoring unit, and controls the deposition source so that the amount of dissolved evaporation material falls within a predetermined range.

5. The film forming apparatus according to claim 1, wherein the evaporation material is a wire-shaped evaporation material.

6. The film forming apparatus according to claim 1, wherein the camera unit includes an infrared camera and a visible light camera.

7. A control method for a film formation apparatus comprising: a vacuum chamber; transport rollers arranged inside the vacuum chamber and supporting a film-like substrate; a vapor deposition boat made of a heat-generating material having a storage section for storing an evaporation material to be evaporated onto the substrate supported by the transport rollers; and a vapor deposition source having a material supply section for supplying the evaporation material to the storage section, the vapor deposition boat melting the evaporation material stored in the storage section by applying electrical heat to the evaporation boat, the control method comprising: acquiring a camera image of the molten evaporation material in the storage section; and controlling, based on the camera image, at least one of the supply speed or supply position of the evaporation material in the vapor deposition source to the storage section and the electrical power applied to the evaporation boat.

Images