JPH01256543A - Plasma treatment apparatus - Google Patents

Abstract

PURPOSE:To suppress unnecessary plasma discharge near the electrodes as much as possible, by radially arranging ungrounded electrodes connected to a power supply part provided at the center. CONSTITUTION:A power supply part 1 is provided at the center of a plurality of ungrounded electrodes 4 in a vacuum vessel A which can withstand a pressure difference between the inside and outside pressures of at least 1atm, and the radially extending electrodes 4 are supported by a plurality of electrode supporting members 2 extending from the supply part 1. The supply part 1 is electrically connected to each electrode 4 and grounded electrodes 5 are arranged in positions equally distant from both surfaces of this electrode 4. A cloth 8 in a vacuum vessel B is supplied from a supply roller 9 through a guide roller 21 and a path 17 to the vessel A, subjected to plasma treatment by passing it through the gap between the electrodes 4 and 5 through guide rollers 6 and 7, led to a vacuum vessel C through a guide roller 22 and wound around a winding roller 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a continuous plasma processing apparatus for elongated objects. More specifically, plasma treatment of long objects such as membranes, films, sheets, cloth, fibers, etc., especially long objects that are flat or relatively thin and wide (hereinafter sometimes referred to as treated fabrics). The present invention relates to a device for continuously performing

(Prior Art) Many proposals have been made in the past regarding plasma processing apparatuses, particularly plasma processing apparatuses for flat sheet-like objects and long objects. For example, Special Publication No. 60-11149, No. 60-319
Publication No. 39 proposes a plasma processing apparatus in which a cloth is passed between a pair of opposing electrodes with a large area.
Also, JP-A-60-134061, JP-A No. 61-22802
No. 8, Special Publication No. 60-59251, No. 61-36862
The publication proposes a plasma processing apparatus in which a plurality of non-grounded electrodes are arranged around a cylindrical grounded electrode. Further, Japanese Patent Publications Nos. 11150/1980 and 54428/1987 propose a plasma processing apparatus having multilayered parallel plate electrodes.

(Problem to be solved by the invention) However, the above-mentioned Japanese Patent Publication No. 11149/1983, 60-
The proposal in Publication No. 31939 has problems such as non-uniform treatment due to local variations in the degree of treatment on a large electrode surface and a decrease in treatment efficiency due to plasma discharge occurring above, below, left and right of the electrode. Also, the above-mentioned Unexamined Patent Publication No. 60-1
In the proposals of Publication No. 34061 and others, the processing area of the electrode cannot be made very large, and discharge loss around the non-grounded electrode cannot be avoided. Said Special Public Service 1986-11
In the proposal of No. 150 and Publication No. 60-54428, there is a problem in obtaining stable operation and quality due to the phase shift of high frequencies etc. occurring in each multilayered electrode 1- and mutual interference between the electrodes. .

As described above, none of the conventionally known plasma processing apparatuses can fully satisfy all of the requirements of operational safety, quality uniformity, and processing efficiency relative to input power.

In order to eliminate the drawbacks of these conventionally proposed devices, the present inventors have developed a vacuum container and a plurality of non-grounded electrodes disposed therein, each having a curved processing surface that bulges with respect to the running direction of the object to be processed. and a grounding electrode provided opposite to the surface of the non-grounded electrode to be treated, the plasma processing apparatus comprising a guide means for passing the object to be processed between the non-grounded electrode and the grounded electrode. It was proposed as No. 61-171464.

Although this proposed device succeeded in solving many of the various technical problems faced by conventionally known devices, as a result of continued research, improvements were made in terms of making the device more compact and improving processing efficiency. However, the present inventors found a need for further improvement and completed the present invention.

An object of the present invention is to provide a plasma processing apparatus which has a plurality of electrodes, but which does not cause mutual interference of plasma between the electrodes and which suppresses unnecessary and harmful plasma discharges around the electrodes as much as possible. It is on offer. Another object of the present invention is to provide an apparatus that can operate more stably and produce high quality and uniform processed products more efficiently.

(Means for Solving the Problems) The present invention provides a vacuum container, a plurality of non-grounded electrodes disposed in the vacuum container, each having a curved processed surface that bulges with respect to the traveling direction of an object to be processed, and In a plasma processing apparatus comprising grounded electrodes disposed opposite to each other and equipped with a guiding means for passing the object to be processed between the non-grounded electrode and the grounded electrode, electric power is supplied to the center of the non-grounded electrode group. The plasma processing apparatus is characterized in that an introduction section is arranged, and the non-grounded electrodes connected to the power introduction section are arranged radially.

The objects to be treated to be applied in the present invention are not particularly limited as long as they are long, flat, or relatively thin, such as membranes, films, sheets, cloth, fibers, and threads.

The present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

FIG. 1 is a partially omitted schematic front view showing a specific example of the present invention;
FIG. 2 is a schematic side view thereof, and FIG. 3 is a schematic front view of a plasma processing chamber which constitutes a main part of the apparatus of the present invention.

In FIGS. 1 and 2, the vacuum container consists of three horizontal cylindrical containers A, B, and C; container A;

B and containers A and C communicate with each other by passages 17 and 18, respectively. Container A is a plasma processing chamber, Container B is
C separately accommodates a supply roller 9 and a take-up roller 10 for the treated fabric 8, respectively. Containers B and C can be combined into a single container that contains both the blank supply roller 9 and the take-up roller 10, or all can be housed in one container A and containers B and C can be combined. It is also possible to omit it with a simple design change.

In Figure 3, which describes the details to the container, the non-grounded electrode 4
A power introduction part 1 is located approximately at the center of the group, and a plurality of electrode connecting members 2 extending from the power introduction part support a plurality of non-grounded electrodes 4 arranged radially and connect the power introduction part 1 and the plurality of electrode connecting members 2. Electrically connect each non-grounded electrode. Power introduction part 1
is electrically insulated and supported by the vacuum container by an insulated bearing portion 3, and is coupled to a terminal 15 from a high frequency power source. The electrode connecting member 2 and the non-grounded electrode 4 do not necessarily need to be coaxial. However, it is preferable to equalize the electrical resistance and distance from the electrode connecting member 2 to each non-grounded electrode 4 in terms of balance of power distribution.

Although the angles formed by the circumferentially extending axes of adjacent non-grounded electrodes do not have to be equal, it is most preferable that they be equiangular radial.

As shown in FIG. 3, the non-grounded electrode 4 is shaped to have a treated surface that bulges in the running direction of the treated fabric in order to bring the treated fabric into efficient and stable contact with its surface. The curvature and shape of the bulging surface must be selected appropriately depending on the length of the electrode, the diameter of the front and rear guide rollers, the ease of deformation of the treated fabric, and the applied tension. It is sufficient if it is 1/100 or more, and 175
It is more preferable if it is 0 or more. A guide roller 6.7, which is a guide means for the treated fabric, is provided at a position that brings the object to be treated into better contact with the non-grounded electrode.

The ground electrode 5 facing the non-ground electrode 4 may have a rod shape or a flat plate shape, but preferably has a concave curved surface corresponding to the bulged surface of the non-ground electrode, and more preferably has a concave surface with the same curvature.

This improves the uniformity of plasma discharge between the electrodes, making it possible to improve the uniformity of the quality of the processed material.

The grounded electrode and the non-grounded electrode are preferably arranged in a radial pattern extending from near the center of the vacuum container to the periphery.

It is preferable that the ground electrode 5 and the non-ground electrode 4 are installed with equal surface spacing.

The distance between surfaces varies depending on the input energy, electrode shape, degree of vacuum, processing speed, and processing method such as plasma etching, plasma polymerization, or plasma CVD. It is better to make it narrower, usually less than 10c+a, preferably 5c
It is m. For example, in the case of oxygen plasma, the degree of vacuum is l m
At about mHg, about 0.5 to 3 cffi is effective. The materials of the non-grounded electrode 4 and the grounded electrode 5 are preferably highly conductive metals, such as aluminum, copper, iron, stainless steel, and various metal platings thereof. Shape: flat plate, punched plate, or mesh (wire mesh)
However, if the input power is Q, 1w/ca+2 or more, a flat plate without holes or irregularities is preferable.

It is preferable that the non-grounded electrode 4 and the grounded electrode 5 have a passage for a temperature regulating medium therein to enable temperature regulation, particularly cooling. Any medium can be used as long as it has fluidity, but pure water, which is an electrical insulator, organic solvents, various heat exchange gases, and steam are preferred. Further, as a temperature control device or a cooling device, it is preferable to install a serpentine pipe or a jacket through which a refrigerant passes through the refrigerant passages 19 and 20 on the electrodes. By controlling the temperature of the electrode, the substrate temperature can be set to the most appropriate temperature according to various plasma treatments (eg, plasma polymerization, plasma CVO, plasma etching, etc.).

In this way, the temperature of the non-grounded electrode can be set arbitrarily, and
This allows the treated fabric to come into contact with the non-grounded electrode, allowing stable treatment over a long period of time.

Vacuum container B accommodates a supply roller 9 for the treated fabric, and vacuum container C accommodates a take-up roller IO driven by an electric motor 16 or the like. Supply roller 9 and take-up roller 10
Therefore, it is preferable to make the coupling mechanism of the electric motor 16 reversible by making it possible to drive the coupling mechanism between the two as appropriate.

It is easy to appropriately design the shape and structure of the vacuum container A so that the supply roller 9 and the take-up roller 10 can be accommodated in the vacuum container A.

Inside the vacuum container A, there is also a guiding means, such as a guide bar, for sequentially guiding the treated fabric 8 fed from the supply roller 9 into the gap between the grounded electrode and the non-grounded electrode and winding it onto the winding roller IO. Guide rollers 6.7 are arranged at appropriate positions near the base and tip of each electrode. As these guide means, fixed rolls, driven rolls, drive rolls, or a combination thereof can be used as appropriate depending on conditions such as fabric weight, running speed, tension, etc., and the treated fabric can run in sliding contact with the non-grounded electrode surface. Adjust and arrange accordingly.

Roller 6 for running the treated fabric through the plasma space
．． The material 7 is preferably a metal, ceramic, metal-coated ceramic, or rubber coating such as NBR or silicone, which has less etching property than the treated fabric and has excellent heat resistance. It is also better for the rollers to be grounded. The surface of the roller is preferably mirror-finished in order to prevent the treated fabric from slipping. More preferably, silicone rubber, SBR rubber, SBR rubber, fluororubber, etc. are used for running stability of the treated object and prevention of heating.
It is best to use a rubber coating or a rubber tube.

Main components such as a non-grounded electrode, a grounded electrode, a treated fabric guide means, and a power introduction part in the vacuum container are supported by a frame 13, and are covered with a cover 14 that connects the grounded electrodes to each other, so that they are integrated. It travels on the guide rail 23 and is loaded and unloaded into the vacuum container.

The material of the cover 14 may be an insulating material or a conductive material.
Preferably the same material as the electrode material, such as stainless steel,
It is made of aluminum, copper plate, etc., and more preferably has a see-through window in the center for monitoring the plasma space. The material for the see-through window may be organic or inorganic as long as it can be seen through, but inorganic materials with excellent plasma resistance and heat resistance, such as glass and inorganic crystals, are preferable. Further, it is preferable that the cover be grounded, and in this case, the distance between the cover and the non-grounded electrode is preferably larger than the distance between the grounded electrode and the non-grounded electrode in terms of plasma stability and uniformity.

The shape and dimensions of the vacuum container are not particularly limited as long as they can withstand an internal and external pressure difference of at least 1 atmosphere. It has an opening/closing device for loading and unloading, and is preferably equipped with a see-through window for monitoring the contents.

The shape of the gas outlet of the gas introduction hole 11 should be an elongated slit or have many small holes, and the gas outlet should be present over the entire width of the electrode to ensure an even ratio of the introduced gas to the decomposed gas. , which is preferable because a stable treatment effect can be obtained. Organic materials such as plastic may be used for the gas introduction piping, but for long-term stable use, metals that are chemically stable, have high plasma resistance, and can withstand high temperatures, such as stainless steel pipes and steel pipes, are recommended. , an aluminum tube, a glass tube, etc. are preferable.

(Function) In the illustrated example of the apparatus of the present invention, the fabric in the vacuum container B starts from the supply roller 9, has its travel path regulated by the guide roller 21, enters the vacuum container A through the passage 18, and enters the vacuum container A, where it enters the vacuum container A from the supply roller 9. After passing through the gap, the guide roller 2 is removed from the passage 19 again.
2 and is wound up on a winding roller 10.

In the present invention, the treated fabric 8 travels inside the plasma sheath generated near the non-grounded electrode, preferably within 5 mm from the non-grounded electrode, and more preferably comes into contact with the non-grounded electrode. In the conventional method, the object to be processed was moved floating on the grounded electrode or between the non-grounded electrode and the grounded electrode, so the processing speed and effect were insufficient, and in order to achieve a certain degree of effect, it was necessary to Required processing equipment. Furthermore, in the present invention, the non-grounded electrode shape has a treated surface that bulges in the running direction of the treated fabric, and the effect of contacting the object to be treated with the non-grounded electrode is very high. Therefore, extremely uniform processing can be performed with low output and in a short time.

The reason for the effect of keeping the object to be processed in the present invention in contact with the plasma sheath, preferably with an ungrounded electrode, is not clear, but a negative self-bias is generated in the ungrounded electrode, accelerating positively charged particles in the plasma. It is presumed that this is because the particles collide with the object to be processed.

Electric power for plasma is introduced centrally through the power introduction section l. Electric power is introduced into each non-grounded electrode 4 from the power introduction section 1 through the electrode connection member 2.

In addition, since the power supply has only one power introduction part, a single power supply can be used, and when multiple power supplies are used, mutual interference of high frequencies due to differences in oscillation frequency, etc. between each power supply, and plasma imbalance are avoided. Balance is almost gone.

The non-grounded electrode 4 has a frequency of 50 Hz for plasma generation.

Power at a commercial frequency of 60 Hz, a low frequency of kilohertz, and a high frequency in the megahertz to gigahertz range is introduced to generate a cold gas plasma with a ground electrode.

Several KHz is required for stable generation of low-temperature gas plasma.
A low frequency or high frequency from 1 to several hundred KHz is preferable, but 1
A high frequency of 3.56 MHz is particularly preferable in terms of processing efficiency, processing cost, and the like. In addition, low-frequency or high-frequency human power energy varies depending on the electrode shape, distance between electrodes, degree of vacuum, processing speed, etc., but is usually 0.01 w/unit area.
cm' or more, preferably 0.2 to IQ w/cm2, more preferably O,1 to lw/cm2.

As the gas for generating low-temperature gas plasma, non-polymerizable gases such as oxygen, nitrogen, argon, helium, and hydrogen, and polymerizable organic monomer gases such as methane, ethane, propane, butane, benzene, acrylic acid, and styrene may be used. You can choose according to your purpose.

For plasma etching of polyester fibers, etc., oxygen,
Air, nitrogen, argon, hydrogen, carbon dioxide, helium and C
F,, CF2Cl,, CFCl3. Single or mixed gases of halogenated hydrocarbons such as CHF3 and their derivatives can be used.

The degree of vacuum in the plasma space is usually 0.0, which is the region where low-temperature gas plasma is stably generated. Old ~10aunHg,
Preferably 0.1-5 mm11g, more preferably 0
．． Adjust to 2~l +u+Hg. The degree of vacuum can be adjusted by adjusting the pumping speed and introducing a gas or monomer gas, but in order to perform the desired treatment preferably, it is preferable to adjust the introduced gas.

The gas is preferably introduced through a gas introduction pipe and blown out toward the processing surface of the object to be processed. As a result, the newly introduced gas always comes into contact with the processing surface of the object to be processed, and the decomposed gas generated by the plasma processing is efficiently discharged from the plasma space. The ratio of introduced gas to cracked gas is at least 1, preferably 2 or more, more preferably 4.
That's all. Increasing the efficiency of plasma processing and preventing foreign reactions has a major impact on how efficiently the introduced gas is turned into plasma and applied to the surface of the object to be treated, and how efficiently decomposed gas is removed and discharged from the surface of the object to be treated. be done.

The cover 14' connecting the ground electrodes functions to efficiently replace the introduced gas and decomposed gas.

Preferred embodiments of the device of the present invention are summarized and described below.

(1) The device according to claim 1, wherein the non-grounded electrode surface is concave.

(2) The device according to claim 1, wherein the non-grounded electrode surface and the grounded electrode surface face each other with an equal inter-plane distance.

(3) The device according to claim 1, wherein the temperature of the non-grounded electrode surface and/or the grounded electrode surface is adjustable.

(4) The apparatus according to claim 1, wherein the object to be processed contacts the surface of the non-grounded electrode.

(Effects of the Invention) In the plasma processing apparatus according to the present invention, since the distances from the power introduction part to the non-grounded electrodes can be made equal, it is possible to introduce power of the same phase to each of the plurality of non-grounded electrodes. Now you can.

Also, because the power introduction part for each electrode could be unified, a single power source was required. Therefore, it is possible to prevent mutual interference of plasma between multiple electrodes and mutual interference between multiple power supplies, which was observed in conventional plasma processing equipment with multilayered electrodes, and to obtain stable operation and stable quality. Became.

Additionally, the space around the ungrounded electrode is much narrower than in the past, reducing unnecessary plasma discharge in this area and making more efficient use of input power.

As described above, the apparatus of the present invention can provide a plasma processing apparatus and treated fabric that are significantly lower in cost, higher quality, and more stable than conventional apparatuses.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted schematic diagram showing a specific example of the device of the present invention.
FIG. 2 is a schematic side view thereof, and FIG. 3 is a schematic front view of a plasma processing chamber that constitutes a main part of the apparatus of the present invention. A, B, C...Vacuum container 1...Power introduction part 2
...Electrode connecting member 3...Insulated bearing part 4...
Non-grounded electrode 5... Grounded electrode 6.7... Guide means 8... Treated fabric 9... Supply roller
10... Winding roller 11... Gas introduction hole
12...Exhaust hole 13...Frame 1
4...Cover 15...Terminal 16...
・Electric motors 17, 18・t・Passage 21, 22...Guide roller 23...Guide rail Patent applicant Kanebo Co., Ltd. Figure 2

Claims (1)

[Claims] 1. A vacuum container, a plurality of non-grounded electrodes disposed therein and each having a curved processed surface that bulges with respect to the traveling direction of the object to be processed, and a grounded electrode provided opposite to the non-grounded electrode processed surface. In the plasma processing apparatus equipped with a guide means for passing the object to be processed between the non-grounded electrode and the grounded electrode, a power introduction part is disposed in the center of the non-grounded electrode group, and the power introduction part is arranged in the center of the non-grounded electrode group. A plasma processing apparatus characterized in that the non-grounded electrodes are arranged in a radial manner, each of which is connected to a corresponding part of the non-grounded electrode.