JPH04168281A - Atmospheric pressure glow plasma device - Google Patents

Abstract

PURPOSE:To uniformize film formation of a large area by constituting at least either of a high-voltage electrode and a grounding electrode of a conductive net electrode and supplying reactive gases to a discharge space disposed with a material to be formed with a film from the outer side of this net electrode. CONSTITUTION:Dielectrics 3 are interposed in a discharge space 4 between the high-voltage electrode 10 and a grounding electrode 2 and the body 6 to be formed with film is disposed on the grounding electrode 2. A high voltage is impressed between these electrodes to generate a glow discharge or voiceless discharge near the atm. in the discharge space 4. The reactive gases are introduced into this discharge gap and the film is formed on the body 6 to be formed with film by plasma. The high-voltage electrode 10 of the above-mentioned atm. glow plasma device is constituted of the conductive wire net electrode and the reactive gases are supplied to the discharge space 4 from the outer side of the wire net electrode 10 via a blow-out pipe 5. The distribution of the reactive gases on the surface of the material 6 to be formed with film is uniformized in this way and the film of the large area is formed with the small-sized device.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an atmospheric pressure glow plasma device capable of forming a thin film by turning organic and inorganic compound gases into plasma under atmospheric pressure. The present invention relates to an atmospheric pressure glow plasma apparatus that enables film formation over a large area by uniformly distributing the gas on the surface of a material to be film-formed by supplying a reactive gas to a discharge space through the film.

Conventional technology Today, dry brating methods include vacuum evaporation, ion blating, sputtering, and CVD (chemical vapor deposition), which form thin films on the surfaces of various materials or surface-treat them with compositions depending on their uses and purposes. ing.

In addition, there is plasma CVD as a technology for growing thin films using gas plasma, and the reaction depends on the frequency band of the applied electric field.There are various film forming methods using discharge plasma such as capacitive coupling type, inductive coupling type, and ECR type. It is widely used.

This is a method for forming thin films by converting organic and inorganic compound gases into plasma. For example, a method in which hydrocarbon gas is plasma excited in a vacuum container to deposit an amorphous carbon film on the surface of a silicon or glass substrate, or a method in which a plasma polymerized film of unsaturated hydrocarbon such as ethylene is formed. .

The above-mentioned various thin film forming methods, film forming methods using discharge plasma, and surface treatments all involve reactions in a required vacuum atmosphere, and vacuum equipment and reaction chamber equipment suitable for each method are essential.

Problems to be Solved by the Invention There are problems such as large device parts cannot be placed in a required vacuum reaction chamber, and device parts with complicated shapes are difficult to form into films.

Furthermore, it is generally difficult to form a desired film on a material with a large area such as a sheet material using low-pressure discharge plasma in a vacuum atmosphere, and furthermore, it has been impossible to form a film continuously on a sheet material. .

Therefore, we considered applying an atmospheric pressure glow plasma device that can form films under atmospheric pressure.

The basic structure of the atmospheric pressure glow plasma device will be explained based on FIG. 4. A dielectric material (3) larger than the electrodes is provided on both the high voltage electrode (1) and the ground electrode (2), and the two are separated at a required interval. That is, it has a configuration in which reactant gas blow-off tubes (5X5) are placed facing each other with a discharge gap (4) in between, and on both sides of a pair of dielectrics (3X3), facing the discharge gap (4). A configuration in which a dielectric is provided only on one electrode,
Alternatively, there is a structure in which one electrode is formed of a large number of wires and a dielectric material is provided on the other electrode, and a structure in which reaction gas blow-off tubes (5×5) are arranged on both sides of the wire electrode.

When performing film formation on a material to be film-formed (6) having a large area using an atmospheric pressure glow plasma apparatus having such a configuration, it is necessary to arrange a reaction gas blow-off pipe (5 x 5) in the discharge gap (4). , the gas distribution on the surface of the film-forming material (6) becomes uneven.

Therefore, in order to make the reaction gas blow out uniformly, it is necessary to insert the reaction gas blow-off pipe (5) into the discharge gap (4) as shown in FIG.

However, the gap length between the picture electrodes (IX2) is at most 15
The diameter is about ~20 mm, and if it is larger than this, the glow discharge tends to become rough, so if you insert a reactant gas blow-off tube that is larger and longer than the gap length, it will conversely block the discharge gap and worsen the gas distribution and plasma distribution. It turns out.

In view of the current situation, this invention utilizes gas plasma to form thin films on a wide range of flat surfaces such as sheet materials under atmospheric pressure, perform surface treatments such as surface modification, and surface treatments of complex shapes, as well as blow out reactive gases. The purpose of the present invention is to provide an atmospheric pressure glow plasma device that can be uniformly and easily performed, and also to provide a surface treatment device for in-line processing that is small and has a simple configuration.

Means for Solving the Problems This invention provides a method for arranging a film-forming material in a discharge space formed between a high-voltage electrode and a ground electrode or on the ground electrode side, and applying a high voltage between the electrodes to reduce atmospheric pressure. In an atmospheric pressure glow plasma device that forms a film by introducing a monomer gas depending on the type of film to be formed or a reactive gas consisting of a plasma gas and an inert gas depending on the process into a discharge gap where a glow discharge or silent discharge occurs nearby, This is an atmospheric pressure glow plasma device characterized in that at least one of the high voltage electrode and the ground electrode is constituted by a conductive mesh electrode, and a reactive gas is supplied to the discharge space from the outside of the mesh electrode.

Function This invention comprises a conductive mesh electrode made of a conductive material such as a wire mesh or carbon fiber as an electrode on one side of a discharge gap, a reactive gas blowing pipe is arranged outside the mesh electrode, and a dielectric material is provided. By using a structure that blows out the reactive gas into the discharge gap where plasma is generated between the counter electrode and the counter electrode, the blowing out of the reactive gas can be made uniform when forming a thin film on a wide range of flat surfaces such as sheet materials under atmospheric pressure. It is characterized by being able to form a film with specific properties.

The atmospheric pressure glow plasma device according to the present invention includes, for example,
A configuration in which one electrode is made of a wire mesh and a reactive gas blowing pipe is placed outside the wire mesh electrode, or a configuration in which one electrode is made of a wire mesh and the reactive gas is blown out from a duct placed above the wire mesh electrode. In both the batch method in which the material to be coated is fixed and the continuous process in which the material to be coated is moved, at least one of the high-voltage electrode and the ground electrode is made of a wire mesh, and the reactive gas is supplied from the outside of the wire mesh electrode to the discharge gap. Any configuration can be adopted.

In this invention, the wire diameter and mesh of the wire mesh used for the electrode are factors that determine the thickness of the plasma glow, and a wire mesh with a small wire diameter and small mesh is desirable for uniform film formation. However, if the wire diameter is too small, the wire mesh will become clogged in a short time due to the film forming action on the wire mesh caused by gas blowing, so the wire diameter and mesh of the wire mesh must be selected appropriately depending on various conditions such as the discharge gap size. There is.

In addition, the concentration of glow is uneven in the 2 to 3 mm portion of the discharge gap close to the wire mesh, and the glow becomes uniform as it moves away from the wire mesh, so it is preferable to determine the width of the discharge gap in consideration.

Example Ryunagi The atmospheric pressure glow plasma device shown in Fig. 1 uses a wire mesh electrode (10) with the required wire diameter and mesh as the high voltage electrode, and a dielectric material (3) larger than the electrode as the ground electrode (2). The wire mesh electrode (10) and the ground electrode (2) are placed opposite to each other with a discharge gap (4) at the required interval, and a reactive gas blow-off pipe (5×5) is placed above the wire mesh electrode (10) so that the air outlet It is configured so that the air gap (4) is visible.

Into the discharge gap (4) maintained at atmospheric pressure, for example, an inert gas and a monomer gas are pumped through the wire mesh electrode (10) and mixed to form a reaction gas.
By applying a required voltage between 0) and the ground electrode (2), a glow discharge occurs and plasma excitation of the reactive gas occurs, turning into gas plasma and discharging the dielectric material (3) on the ground electrode (2) side.
) A thin film can be formed on the surface of the film-forming material (6) in accordance with the type of the reaction gas.

Example 2 The atmospheric pressure glow plasma device shown in FIG. 2 has wire mesh electrodes (I
OXII), the high-voltage side wire mesh electrode (10) and the ground side wire mesh electrode (11) are made to face each other with a discharge gap (4) of a required interval interposed therebetween, and a dielectric material that is wider than the electrode is placed in the center of the discharge gap (4). (3), and a reactive gas blow-off pipe (5×5) is arranged outside each wire mesh electrode (IOXII) so that the blow-off port faces the discharge gap (4).

The dielectric material (3) in the discharge gap (4) is maintained at this atmospheric pressure.
) The film-forming target material (6) placed on each wire mesh electrode (I
A required voltage is applied between the two wire mesh electrodes (10) and (11) to generate plasma excitation, and the reaction gas pumped through the reactant gas (OXII) generates plasma excitation, which causes a reaction gas to form on the surface of the film-forming material (6) according to the type of the reaction gas. A thin film can be formed.

Fat! The atmospheric pressure glow plasma device shown in FIG. 3 has the same configuration as that shown in FIG. (4) The reactant gas is blown out from a duct (7) arranged so as to enclose the reaction gas.

The reaction gas is sent from the duct (7) through the wire mesh electrode (10) to the discharge gap (4) near the outlet of the duct (7), which is maintained at atmospheric pressure, and the material to be deposited ( 6) A thin film can be formed on the surface depending on the type of the reaction gas. This makes the distribution of the gas flow uniform, making it possible to form a more homogeneous film.

Effects of the Invention The atmospheric pressure glow plasma device according to the present invention has a configuration in which at least one of the high-voltage electrode and the ground electrode is made of a wire mesh, and a reactive gas is supplied from the outside of the wire mesh electrode to the discharge space. It is possible to equalize the gas blowout distribution and to make the film formation uniform. (2) It is possible to form a film on a large area of a material to be film-formed.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 are explanatory diagrams showing an embodiment of an atmospheric pressure glow plasma device according to the present invention. FIGS. 4 and 5 are explanatory diagrams showing the configuration of a conventional atmospheric pressure glow plasma device. DESCRIPTION OF SYMBOLS 1... High voltage electrode, 2... Ground electrode, 3... Dielectric, 4... Discharge gap, 5... Reactant gas blow-off pipe, 6...
- Film-forming material, 7... duct, 10.11... wire mesh electrode.

Claims (1)

[Claims] 1. A film-forming material is placed in a discharge space formed between a high-voltage electrode and a ground electrode or on the ground electrode side, and a high voltage is applied between the electrodes to generate a glow discharge near atmospheric pressure. Alternatively, in an atmospheric pressure glow plasma device that forms a film by introducing a monomer gas depending on the type of film to be formed or a reactive gas consisting of a plasma gas and an inert gas depending on the process into the discharge gap where silent discharge occurs, the high-voltage electrode and the ground are used. An atmospheric pressure glow plasma device characterized in that at least one of the electrodes is constituted by a conductive mesh electrode, and a reactive gas is supplied to a discharge space from the outside of the mesh electrode.