JPH0518331B2 - - Google Patents

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,
Japanese Patent Laid-open No. 60-31939 proposes a plasma processing apparatus in which a cloth is passed between a pair of opposing electrodes with a large area;
No. 61-228028, Special Publication No. 60-59251, No. 61-
No. 36862 each proposes a plasma processing apparatus in which a plurality of non-grounded electrodes are arranged around a cylindrical grounded electrode. Furthermore, Special Publication No. 60-11150, same
No. 60-54428 each proposes a plasma processing apparatus having multilayered parallel plate electrodes.

(Problem to be solved by the invention) However, the above-mentioned Japanese Patent Publication No. 11149/1986, 60-
The proposals in each publication of No. 31939 have 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.
Further, in the above-mentioned Japanese Patent Application No. 60-134061 and other proposals, the processing area of the electrode cannot be made very large, and discharge loss around the non-grounded electrode cannot be avoided. Said Special Publication No. 11150, No. 60-
In the proposals of each publication of No. 54428, there is a problem in obtaining stable operation and quality due to a phase shift of high frequencies etc. occurring on each multilayered electrode 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 in the vacuum container and having a curved processing surface that bulges with respect to the traveling direction of the object to be processed. a ground electrode provided opposite to the non-ground electrode treated surface;
A plasma processing apparatus equipped with a guide means for passing the object to be processed between the non-grounded electrode and the grounded electrode was originally proposed in Japanese Patent Application No. 171464/1983. Although this proposed device succeeded in solving many of the various technical problems associated with conventionally known devices,
As a result of continued research, the device was made more compact,
The present inventors have discovered the need for further improvements in terms of improved processing efficiency, etc., and have 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 cover discharges around the electrodes as much as possible. It is on offer. Another purpose is to enable more stable driving,
Another object of the present invention is to provide an apparatus that can more efficiently produce high-quality and uniform processed products.

(Means for Solving the Problems) The present invention includes a vacuum container, a plurality of non-grounded electrodes arranged in the vacuum container, each having a curved processed surface that bulges with respect to the running direction of an object to be processed, and a non-grounded electrode processed surface. 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 forming 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, and the containers A, B and C communicate with each other by passages 17 and 18, respectively. Container A is a plasma processing chamber, and containers B and C separately accommodate a supply roller 9 and a take-up roller 10 for treated fabric 8, respectively.
Containers B and C can be combined into a single container that contains both the supply roller 9 and the take-up roller 10, or they can all be stored in one container A and containers B and C can be combined. It is also possible to omit it by a simple design change.

In FIG. 3 illustrating details of the container A, the power introduction part 1 is located approximately at the center of the four groups of non-grounded electrodes,
A plurality of electrode connecting members 2 extending from the power introduction part
supports a plurality of non-grounded electrodes 4 arranged radially, and electrically connects the power introduction part 1 and each non-grounded electrode. The power introduction part 1 is electrically insulated and supported by the vacuum container by an insulating bearing part 3, and is coupled with 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 used to efficiently and stably contact the treated fabric with its surface.
The treated fabric has a shape with a swollen treated surface in the direction of travel of the treated fabric. 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 that the height is 1/100 or more, and more preferably 1/50 or more. Guide rollers 6 and 7, which are means for guiding the treated fabric, are provided at positions that allow the object to be treated to better contact 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, but in general, when the degree of vacuum is small and the input energy is small, It is better to be narrow, usually less than 10 cm, preferably 5 cm. For example, in the case of oxygen plasma, when the degree of vacuum is about 1 mmHg, 0.5
~3cm 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 0.1 W/cm 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 exchange gases, and steam are preferred. Further, as a temperature control device or a cooling device, it is preferable to install a coiled pipe or a jacket through which a refrigerant passes through refrigerant passages 19 and 20 at the electrodes. By controlling the temperature of the electrode, the substrate temperature can be set to the most appropriate temperature for various plasma treatments (eg, plasma polymerization, plasma CVD, plasma etching, etc.). In this way, the temperature of the non-grounded electrode can be set arbitrarily, and the treated fabric can be brought into contact with the non-grounded electrode, thereby 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 10 driven by an electric motor 16 or the like. Supply roller 9
By making the coupling mechanism of the electric motor 16 between the winding roller 10 and the winding roller 10 reversible as appropriate,
It is preferable to make it reversible.

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

Inside the vacuum container A, there is also a guide 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 10. Guide rollers 6 and 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.

The material of the rollers 6 and 7 for running the treated fabric through the plasma space may be 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. etc. is good. 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, NBR rubber, SBR rubber,
It is preferable to use a rubber coating such as fluorocarbon rubber 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, but it is preferably made of the same material as the electrode material, such as stainless steel, aluminum, copper plate, etc., and more preferably has a see-through window in the center for monitoring the plasma space. Good. 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 better that the cover is 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 plastics can 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, steel pipes, etc. An aluminum tube or a glass tube is preferable.

(Function) In the illustrated example of the device of the present invention, the vacuum container B
The running path of the fabric from the supply roller 9 is regulated by the guide roller 21, it enters the vacuum container A through the passage 18, passes through the electrode gap, and is again guided by the guide roller 22 through the passage 19 to be wound up. It is wound around a 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. Further, 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 intensively by the power introduction section 1. Power introduction section 1 is connected to each non-grounded electrode 4.
Electric power is introduced through the electrode connecting 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 occur. almost disappears.

The non-grounded electrode 4 has 50Hz and 60Hz for plasma generation.
Power at commercial frequencies in Hz, low frequencies in kilohertz, and high frequencies in the megahertz to gigahertz range is introduced to generate a cold gas plasma between a ground electrode.

For stable generation of low-temperature plasma, several K
A low frequency or high frequency from Hz to several hundred KHz is preferable, and a high frequency of 13.56 MHz is particularly preferable in terms of processing efficiency, processing cost, etc. In addition, the input energy of low frequency or high frequency varies depending on the electrode shape, distance between electrodes, degree of vacuum, processing speed, etc., but is usually 0.01w/cm2 ^or more per unit area, preferably 0.2 to 10w/cm2.
^cm2 , more preferably 0.1 to 1w/ ^cm2 .

Gases that generate low-temperature gas plasma include:
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 can be used, and are selected depending on the purpose.

For plasma etching of polyester fibers, etc., oxygen, air, nitrogen, argon, hydrogen, carbon dioxide gas, helium, halogenated hydrocarbons such as CF ₄ , CF ₂ Cl ₂ , CFCl ₃ , CHF ₃ and their derivatives, either singly or in combination, are used. Gas can be used.

The degree of vacuum in the plasma space is the area where low-temperature gas plasma is stably generated, that is, usually 0.01 to 10 mm.
Hg, preferably 0.1 to 5 mmHg, more preferably
Adjust to 0.2-1mmHg. 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, and more preferably 4 or more. In order to improve the efficiency of plasma processing and prevent foreign reactions, it is important to efficiently convert the introduced gas into plasma.
It is greatly influenced by how it is 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. The cover 14 connecting the ground electrodes functions to efficiently replace 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 I can do it.

Additionally, because the power introduction parts 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 is seen in conventional plasma processing equipment with multilayered electrodes, resulting in stable operation and stable quality. It became like that.

In addition, the space around the non-grounded electrode is gradually narrower than in the conventional case, reducing unnecessary plasma discharge in this area and making it possible to use input power more efficiently.

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 front view showing a specific example of the apparatus 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 forming the 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... Ungrounded 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, 14... Cover, 15... Terminal, 16... Electric motor, 17, 18... Passage, 21, 22... Guide roller, 23... Guide rail.

Claims (1)

[Claims] 1 Consisting of a vacuum container, a plurality of non-grounded electrodes disposed therein and each having a curved treated surface that bulges with respect to the running direction of the object to be processed, and a grounded electrode provided opposite to the treated surface of the non-grounded electrodes. , in a 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,
A plasma processing apparatus characterized in that the non-grounded electrodes each connected to the power introduction part are arranged radially.