JPH05287498A - Pretreatment of band plate for vapor deposition treatment and device therefor - Google Patents

Abstract

PURPOSE:To enable pretreating a band plate even in a low pressure by arranging an anode on the band plate to be a cathode, arranging an auxiliary cathode between the cathode and the band plate, generating a glow discharge by impressing, thereby pretreating the band plate. CONSTITUTION:The auxiliary cathode 3 is arranged to be opposed to the lower part of the metallic band plate 2 moving in a pretreating chamber 1. A shielding plate 5 for preventing the discharge is arranged at the place except an opposing surface between the auxiliary cathode 3 and the band plate 2. An anode plate 4 is arranged at the lower parts of the band plate 2 and the auxiliary cathode 3. After the inside of the pretreating chamber 1 is evacuated to vacuum by a vacuum evacuating device 8, a gas for the bombardment treatment is introduced from a gas introducing hole 7 and a potential is impressed between the anode plate 4, and the metallic band plate 2, the auxiliary cathode 3 and the plate 2. By the presence of the auxiliary cathode 3, a discharge having the strong hollow cathode effect is generated and the pretreating of the band plate is available even in a low pressure, and consequently a differential pressure sealing mechanism to a vacuum evaporation device is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretreatment method and apparatus for cleaning a surface of a strip plate to be vapor-deposited by an ion bombardment method.

[0002]

2. Description of the Related Art When vacuum evaporation is continuously performed, a pretreatment for cleaning a metal substrate is performed as a pre-process. As the conventional pretreatment, an ion bombardment method using ordinary glow discharge is applied. Since this method has a low discharge current density, there is a drawback that a very long pretreatment line must be provided or the transport speed of the strip must be slowed in order to reliably clean the continuously moving metal substrate. It was

Further, in the usual ion bombardment method, the processing pressure is about 0.1 to 1 Torr, but since the degree of vacuum in the vapor deposition chamber for performing vacuum vapor deposition is 10 ⁻⁶ to 10 ⁻⁵ Torr, the pressure difference between the two. Is big. For this reason, it is necessary to provide a plurality of special differential pressure seals between the pretreatment chamber and the vapor deposition chamber to cope with this differential pressure. As a result, the device is complicated, long, and expensive.

In order to solve this problem, as shown in FIG. 3, a magnetron electrode 9 in which N poles and S poles of a plurality of magnets are alternately attached below a metal strip 2 passing through the pretreatment chamber 1 is provided.
Is arranged, the cathode side of the DC power supply 6 is connected to the strip plate 2 and the anode side is connected to the magnetron electrode 9, and a method of increasing the current density and lowering the processing pressure with the help of the magnetic field from the magnetron electrode 9 has been devised. ..

However, this method requires special processing such as embedding a magnet in the electrode, and the density of the plasma can be varied due to the distribution of the electric field and the magnetic field, resulting in uneven pretreatment.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to increase the pretreatment current density with a simple electrode arrangement and to reduce the pressure lower than that of the prior art. It is an object of the present invention to provide a pretreatment method and apparatus for a vapor deposition treatment strip that can be pretreated by ion bombardment.

[0007]

That is, the method of the present invention is a pretreatment method for a strip that continuously moves in a pretreatment chamber, in which one or a plurality of anodes are arranged facing the strip, and One or more auxiliary cathodes are arranged between the strip plate and the anode, and a DC voltage is applied between the anode and the strip plate and the auxiliary cathode while introducing a bombarding gas into the pretreatment chamber. This is a pretreatment method for a strip plate for vapor deposition treatment, in which glow discharge is generated to pretreat the strip plate.

Further, the apparatus of the present invention comprises a pretreatment chamber in which the strip moves continuously, one or a plurality of anodes arranged in the pretreatment chamber so as to face the strip, and the strip and the anode. One or a plurality of auxiliary cathodes arranged between them, a cathode side is connected to the strip plate and the auxiliary cathode, and a DC power supply is connected to the anode side to the anode, and a bombarding gas provided in the pretreatment chamber. It is a pretreatment device for a vapor deposition treatment strip having an introduction hole.

[0009]

According to the present invention, the strip that continuously moves in the pretreatment chamber is used as a cathode, and the auxiliary cathode that is separated from the strip by a predetermined distance (about twice the thickness of the space charge layer) is strip. , A DC voltage is applied between the cathode and the auxiliary cathode, and an anode, for example, Ar gas is introduced as a bombarding gas into the pretreatment chamber. This starts the discharge. The distance between the cathode and the auxiliary cathode is 2 of the thickness of the space charge layer.
When doubled, the strong electric field of the space charge layer repels electrons and traps them in the space charge layer, which promotes ionization of the bombarding gas. This is called the hollow cathode effect, and a very high current density can be obtained as compared with a normal glow discharge. Since the number of ions generated by the discharge is closely related to the discharge current, a large current density means a large pretreatment capacity per unit area. In addition, due to the hollow cathode effect, the number of electrons that collide with gas molecules increases in order to confine the electrons in the space charge layer, and it is possible to obtain a sufficient number of ions for pretreatment even at a pressure lower than general glow discharge. You can In this way, uniform and high-density plasma is generated by the hollow cathode effect, and the cations are allowed to collide with the metal strip to perform the ion bombardment process.

[0010]

1 is a sectional view showing a pretreatment apparatus according to an embodiment of the present invention.

In the pretreatment apparatus shown in FIG. 1, a vacuum evacuation apparatus 8 for evacuating the chamber is connected to the pretreatment chamber 1, and the metal strip plate 2 moving in the pretreatment chamber 1 is opposed to the pretreatment chamber 1 at a distance of 20 to 40 mm. The auxiliary cathode plate 3 is arranged. Auxiliary cathode 3 and strip 2
A shield plate 5 for preventing discharge is arranged at a position except the facing surface. And the strip plate 2 and the auxiliary cathode plate 3
And the anode plate 4 is installed below. Further, a gas introduction hole 7 for bombardment treatment is provided in the lower part of the pretreatment chamber 1 so that a gas for bombardment treatment, for example, Ar gas is introduced from here after exhaustion.

After the pretreatment chamber 1 is sufficiently evacuated, a bombarding gas such as argon is added in an amount of 0.01 to 0.1 To.
Introduce about rr, and use DC power supply 6 to anode plate 4 and metal strip 2
And a potential is applied between the auxiliary cathode plate 3 and the auxiliary cathode plate 3. A suitable potential difference is 500 to 1000V. Discharge is started by applying a potential. At this time, electrons in plasma are repulsed by a strong electric field of the space charge layer formed near the cathode, and strong discharge occurs due to the hollow cathode effect (electrons reciprocate in the space charge layer and ionization is promoted).

This discharge is 1 compared with the normal glow discharge.
Not only a current density of 0 times or more can be obtained, but also a current density having a pretreatment ability can be obtained even at a lower pressure (0.01 to 0.1 Torr).

Next, in the case of using the device provided with the above-mentioned auxiliary cathode (the present invention: 0.04 Torr, 0.1 Torr,
0.2 Torr) and a conventional device without an auxiliary cathode for comparison (comparative example: 0.1 Torr,
0.2 Torr) and its current density characteristics were investigated. The result is shown in FIG.

From the results shown in FIG. 2, it can be seen that the current density can be increased ten times or more under the same pressure as compared with the ion bombardment method using a general DC glow discharge with a simple electrode arrangement.

Further, as in the comparative example, when the pressure is 0.1 Torr or less in the general DC glow discharge, the sufficient current density for the pretreatment cannot be obtained, but when the present method is used, the current density is 0.01.
It can be seen that a sufficient current density is obtained up to about Torr, and pretreatment at a lower pressure is possible.

As already mentioned, in general, vacuum deposition is 1
Since it is performed at 0 ⁻⁶ to 10 ⁻⁵ Torr, when the pretreatment and the vacuum deposition are continuously performed, if the pressure of the pretreatment process is high, the pressure difference between the pretreatment process and the vapor deposition process becomes very large. Extra equipment is required to absorb. However, according to the present invention, it is possible to perform the pretreatment with a simple electrode structure and a low pressure. As a result, the differential pressure sealing mechanism can be simplified, the length of the vapor deposition line can be shortened, and the line speed can be increased, which is extremely economical. In addition,
The type of the strip plate is arbitrary such as a steel plate, a stainless steel plate, a Cr steel plate, and a strip plate of metal other than steel.

[0018]

In the pretreatment of the metal strip, the pretreatment current density can be increased with a simple electrode arrangement. further,
Pretreatment by ion bombardment can be performed at a lower pressure than in the conventional method. As a result, the length of the vapor deposition line can be shortened and the line speed can be increased.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a pretreatment apparatus showing an embodiment of the present invention.

FIG. 2 is a diagram showing a comparison of discharge current densities of a DC glow and a hollow cathode.

FIG. 3 is a schematic sectional view of a conventional pretreatment device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pretreatment chamber, 2 ... Metal strip plate, 3 ... Auxiliary cathode, 4 ... Anode plate, 5 ... Shield plate, 6 ... DC power supply, 7 ... Bombard processing gas introduction hole, 8 ... Vacuum exhaust device, 9 ... Magnetron Electrodes, 10 ... Power supply roll

Claims (2)

[Claims] 1. A method for pretreating a strip that continuously moves in a pretreatment chamber, in which an anode is arranged facing a strip serving as a cathode, and an auxiliary cathode is arranged between the strip and the anode. Then
While introducing a gas for bombarding treatment into the pretreatment chamber, a DC voltage is applied between the anode and the strip and the auxiliary cathode to generate glow discharge to pretreat the strip for vapor deposition treatment. Pretreatment method. 2. A pretreatment chamber in which the strip moves continuously, an anode arranged to face the strip in the pretreatment chamber, and an auxiliary cathode arranged between the strip and the anode. In front of the vapor deposition treatment strip having a direct current power source having a cathode side connected to the strip plate and the auxiliary cathode and an anode side connected to the anode, and a bombarding gas introduction hole provided in the pretreatment chamber. Processing equipment.