JP3741161B2 - Splash monitoring device for continuous vacuum deposition equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a splash monitoring device for a continuous vacuum deposition apparatus.
[0002]
[Prior art]
The vacuum deposition apparatus is a film forming process in which a metal is heated and evaporated in a vacuum, and the evaporated metal is solidified on the surface of a substrate (steel plate) to form a film. 2. Description of the Related Art Conventionally, a continuous vacuum vapor deposition apparatus that deposits metal on a thin plate-like continuous traveling steel plate using an electron beam to heat the metal for vapor deposition in such a film forming process is known. This continuous vacuum deposition apparatus has advantages such as deposition of refractory metals, nitrides, carbides, oxides and ceramics that cannot be handled by ordinary wet plating, and a high deposition rate.
[0003]
Such a conventional continuous vacuum vapor deposition apparatus includes, for example, as shown in FIG. 2, a steel sheet that is made up of an inlet and outlet vacuum seal device, a preheating chamber, a film forming chamber, etc., and is unwound from an uncoiler under atmospheric pressure. (Strip) is passed through the vacuum by the vacuum seal device on the inlet side, preheated in the preheating chamber, then formed into a film in the film forming chamber, and the steel plate after film formation is brought to atmospheric pressure by the vacuum seal device on the outlet side. It is designed to be taken up by a take-out recoiler.
[0004]
The film formation chamber includes an electron gun that emits an electron beam and a crucible that accommodates the melted vapor deposition material. The electron beam is emitted by the electron gun, and the direction of the electron beam is bent by a magnetic field and applied to the crucible. The deposition material is heated and evaporated, and the evaporated metal is solidified on the surface of the steel plate to form a coating.
[0005]
[Problems to be solved by the invention]
In the above-described continuous vacuum vapor deposition apparatus, when the electron gun is used as a heat source, if the energy of the electron beam is concentrated on the minimum portion of the molten crucible, splash occurs and adversely affects the deposited film.
That is, the splash is a phenomenon in which the molten metal scatters as droplets, and is caused by local boiling. When the droplets splashed by this splash adhere to the steel plate, a projection of several millimeters thickness is formed at that portion, and this projection interferes with the narrow gap of the vacuum seal device, scratches the roll of the vacuum seal device, When the thickness is thin (for example, about 0.3 mm thick), there is a problem that the steel plate is torn off.
[0006]
In the continuous vacuum vapor deposition apparatus, the film is formed at a high speed of 200 to 500 m / min, and is continuously operated for several hundred hours. For this reason, when the roll is damaged or the steel sheet is cut by the splash, it takes a long time to restart the operation, and the operation rate is significantly reduced. Therefore, conventionally, an operator constantly monitors the crucible, and empirically determines immediately before the occurrence of splash, and closes the output control of the electron gun, the shutter provided on the upper part of the crucible, and the like. However, this monitoring needs to be performed continuously for a long time, which is a heavy burden on the operator and often makes a mistake.
[0007]
The present invention has been made to solve such problems. That is, an object of the present invention is to provide a splash monitoring device for a continuous vacuum vapor deposition apparatus that can prevent the occurrence of splash, and can prevent roll damage and sheet breakage due to splash. .
[0008]
[Means for Solving the Problems]
According to the present invention, a film forming chamber for depositing an evaporation material on a steel plate continuously running in a vacuum, an electron gun for emitting an electron beam into the film forming chamber, and a crucible by bending the direction of the electron beam. In a continuous vacuum vapor deposition apparatus comprising a magnetic field generator for generating a magnetic field directed inward, a monitoring window provided in a film forming chamber, a CCD camera for monitoring molten metal in the crucible through the monitoring window, and the CCD camera And a controller for controlling the output of the electron gun by detecting immediately before the occurrence of a splash by performing image processing on the image of the above, a splash monitoring apparatus in vacuum deposition is provided. The control device detects the temperature change of the molten metal or the wave of the molten metal from the image of the CCD camera, and reduces the output of the electron gun, thereby preventing the occurrence of splash.
[0009]
With this configuration, the temperature change of the molten metal (for example, the change of the molten metal from red to white) or the undulation of the molten metal (for example, enlargement of the difference from the normal stored image by image processing) is controlled from the image of the CCD camera. The occurrence of splash can be suppressed by detecting the device and controlling the output of the electron gun.
[0010]
According to a preferred embodiment of the present invention, at least two CCD cameras are provided so as to monitor the electron beam irradiation area on the crucible. With this configuration, both ends in the width direction of the steel plate of the crucible irradiated with the electron beam can be monitored without being affected by the steel plate traveling above the crucible, and the occurrence of splash can be prevented accurately.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each drawing, common parts are denoted by the same reference numerals.
FIG. 1 is a perspective view of a film forming chamber of a continuous vacuum vapor deposition apparatus equipped with a splash monitoring device according to the present invention (a view excluding the outer body of the film forming chamber). In this figure, the continuous vacuum vapor deposition apparatus includes a film forming chamber 6 for depositing an evaporation material on a steel plate 1 continuously running in a vacuum, an electron gun 3 for emitting an electron beam 2 into the film forming chamber 6, and And a magnetic field generator 7 for generating a magnetic field that bends the direction of the electron beam 2 and directs it into the crucible 5.
[0012]
The steel plate 1 is a normal carbon steel plate or stainless steel plate, for example, a relatively thin steel plate (strip) having a thickness of 0.3 to 3.2 mm is used. The vapor deposition material is, for example, aluminum or an aluminum-based alloy. When an alloy film is formed, two or more crucibles 5 are provided as shown in FIG. To do. The inside of the film forming chamber 6 is evacuated by a vacuum device (not shown) and is maintained at a degree of vacuum suitable for vapor deposition (for example, about 10 ⁻³ to 10 ⁻⁵ torr). In this figure, two electron guns 3 are provided for each crucible, and both ends of the crucible 5 in the steel plate width direction are irradiated with the electron beam 2. In this figure, two magnetic field generators 7 are provided for each crucible, each having magnetic field electrodes 7a and 7b, and the direction of each electron beam 2 is bent and directed into each crucible 5. .
[0013]
The splash monitoring apparatus 10 of the present invention further includes a monitoring window 12 provided in the film forming chamber 6, a CCD camera 14 that monitors the molten metal 4 in the crucible 5 through the monitoring window 12 for each crucible, and an image of the CCD camera 14. And a control device 16 that detects immediately before the occurrence of splash and controls the output of the electron gun 3. As shown in this figure, it is preferable to provide two CCD cameras 14 and one control device 16 for each crucible.
[0014]
The control device 16 detects the temperature change of the molten metal 4 or the undulation of the molten metal from the image of the CCD camera 14 and reduces the output of the electron gun. For example, the color of the molten metal is usually red, but the temperature further increases and changes to white at the portion where splash occurs. Therefore, it is possible to detect the temperature change of the molten metal from the image of the CCD camera 14 and detect immediately before the occurrence of splash. Further, in the portion where the splash is generated, the molten metal is rippled due to bubbles generated inside. This ripple can be detected, for example, from the enlargement of the difference from the normal stored image by image processing. Therefore, when these are detected from the image of the CCD camera 14 by the control device 16, the occurrence of splash can be suppressed by controlling the output of the electron gun 3 (reducing the output).
[0015]
As shown in the figure, at least two CCD cameras 14 are preferably provided so as to monitor both ends in the width direction of the steel plate of the crucible 5. With this configuration, both ends in the width direction of the steel plate of the crucible 5 irradiated with the electron beam 2 are monitored without being affected by the steel plate 1 traveling above the crucible 5, and the occurrence of splash can be prevented accurately. Can do.
[0016]
Moreover, it is preferable to provide a translucent film (not shown) that moves endlessly on the inner surface of the monitoring window 12. With this configuration, the light transmittance of the monitoring window 12 can be kept substantially constant.
[0017]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.
[0018]
【The invention's effect】
As described above, according to the configuration of the present invention, the temperature change of the molten metal (for example, change of the molten metal from red to white) or the undulation of the molten metal (for example, enlargement of the difference from the stored image at normal time by image processing), etc. Is detected from the image of the CCD camera and the output of the electron gun is controlled to prevent the occurrence of splash.
[0019]
Therefore, the splash monitoring device of the continuous vacuum vapor deposition apparatus of the present invention can prevent the occurrence of splash, and has excellent effects such as prevention of roll damage and plate breakage due to splash. Have.
[Brief description of the drawings]
FIG. 1 is a perspective view of a film forming chamber equipped with a splash monitoring apparatus according to the present invention.
FIG. 2 is a configuration diagram of a conventional continuous vacuum deposition apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steel plate 2 Electron beam 3 Electron gun 4 Molten metal 5 Crucible 6 Deposition chamber 7 Magnetic field generator 7a, 7b Magnetic field electrode 10 Splash monitoring device 12 Monitoring window 14 CCD camera 16 Control device

Claims (3)

A film-forming chamber for depositing evaporation material on a steel plate that runs continuously in a vacuum, an electron gun that emits an electron beam into the film-forming chamber, and a magnetic field that bends the direction of the electron beam and directs it into the crucible In a continuous vacuum deposition apparatus comprising a magnetic field generating device,
A monitoring window provided in the film forming chamber, a CCD camera that monitors the molten metal in the crucible through the monitoring window, an image of the CCD camera is processed to detect immediately before the occurrence of splash, and the output of the electron gun is controlled. A splash monitoring device in vacuum deposition, comprising: a control device; 2. The splash according to claim 1, wherein the control device detects a change in temperature of the molten metal or a wave of the molten metal from an image of a CCD camera and reduces the output of the electron gun to prevent occurrence of splash. Monitoring device. The vacuum splash monitoring apparatus according to claim 1, wherein at least two CCD cameras are provided so as to monitor an electron beam irradiation area on the crucible.

Images