JP2000302902A - Continuous plasma-treating and surface processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge the applicability to a material to be treated having various thicknesses and shapes, and further enable a prescribed processing treatment to be very effectively carrying out only to the one-side surface without requiring previous treatment. SOLUTION: A gas flow jetted from a plasma-generating device 2 capable of linearly jetting the gas flow containing a chemically active excited species produced according to the generation of a grow-discharging plasma in an atmospheric pressure, in one direction is irradiated to the surface Sa of one side of the material S to be treated, continuously conveyed by a conveyer 1 to treat the one-side surface S with the plasma, and a prescribed processing treatment such as printing, coating and grafting treatments on the one-side surface Sa after the plasma treatment in the plasma-treating and surface processing method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous plasma processing / surface processing method, and more specifically, for example, polyethylene, polypropylene, PTFE (polytetrafluoroethylene).
Water-repellent plastic or paper, or a sheet-like processed object made of a polymer material containing fibers such as woven fabric, knitted fabric, and non-woven fabric is subjected to plasma treatment to make one surface hydrophilic, hydrophobic, and wettable (adhesive )), And then applied to the surface of one of the plasma-treated ones, such as printing, painting, or processing such as grafting to impart various advanced functions. The present invention relates to a plasma processing / surface processing method.

[0002]

2. Description of the Related Art As a plasma generator for continuously performing surface treatment such as hydrophilicity modification by plasma as described above and subsequent processing such as printing and grafting,
Conventionally, in general, as disclosed in, for example, JP-A-5-235541 and JP-A-6-1995, a flat plate-like high-pressure member arranged in a container at a predetermined interval so as to face each other. A glow discharge plasma is generated by introducing a discharge reaction gas such as oxygen into a discharge portion between the electrode and the ground electrode and applying a high-frequency voltage to both electrodes, thereby generating electrons and chemicals generated by the plasma. There has been used one configured to perform a surface treatment such as modifying the surface of an object to be processed passing between the two electrodes with a gas containing highly active ions and neutral excited species.

[0003]

However, in the conventional general plasma generator having the above-described structure, it is essential that the object to be processed be passed between the electrodes. Not only is it limited by the area, thickness, shape, etc., but it does not hinder the processing of both surfaces of the workpiece, but if you want to process only one surface of the workpiece, the other is unnecessary. It is necessary to perform a pretreatment such as applying a treatment inhibitor to the surface so that the plasma treatment is not performed when passing between the electrodes, and such a pretreatment for preventing the plasma treatment requires a great deal of labor. Therefore, there is a problem that the efficiency of the plasma processing of only one surface is very poor and the productivity is lacking.

[0004] The present invention has been made in view of the above-described circumstances, and not only can expand the applicability to a variety of workpieces having various thicknesses, shapes, and the like, but also requires no pretreatment. It is an object of the present invention to provide a continuous plasma processing / surface processing method capable of performing a predetermined processing only on a semiconductor device very efficiently.

[0005]

In order to achieve the above-mentioned object, a continuous plasma processing / surface processing method according to the present invention provides a discharge part formed between a high-voltage electrode and a ground electrode with at least helium or hydrogen. A reaction gas containing an inert gas containing oxygen and a reactive gas containing oxygen or a fluorine-containing compound (fluorocarbon) gas is introduced and passed under atmospheric pressure or near atmospheric pressure, and high-frequency power is supplied to both electrodes. In this way, a glow discharge plasma is generated in the discharge portion to generate a gas flow containing a chemically active excited species, and the gas flow is ejected from a plasma generator capable of ejecting the gas flow linearly in one direction. By irradiating one surface of the sheet-like workpiece to be continuously or almost continuously conveyed by the conveying device with the gas flow to be performed,
After plasma-treating one surface of the object to be processed,
One of the surfaces of the plasma-processed object is subjected to a predetermined processing.

According to the present invention, only by continuously transporting an object to be processed along a fixed transport path via a transport device, first, glow discharge plasma is generated by a glow discharge plasma generated in a discharge unit of a plasma generator. By irradiating a gas stream containing a chemically active excited species that is ejected linearly in one direction onto the object, only one surface of the object is modified to be hydrophilic, etc. The plasma processing is performed, and subsequently, a predetermined processing such as printing, painting or grafting is performed on one surface of the plasma-processed processing object. A series of processing operations on one surface can be performed continuously and simultaneously without the need for a large amount of time-consuming pre-processing such as applying a processing inhibitor to the other unnecessary surface. It is. As a result, not only can the applicability of the object to be processed having various thicknesses and shapes be expanded, but also the efficiency of the predetermined plasma processing on only one surface of the object to be processed can be increased to improve the productivity. .

[0007] As a plasma generating apparatus used in the continuous plasma processing / surface processing method, as described in claim 2, a solid band-shaped high voltage electrode and both sides in the thickness direction of the band-shaped high voltage electrode are respectively provided. Along with the ground electrode disposed opposite to each other with the insulator interposed therebetween, and on both front and back surfaces at one end side in the plate width direction of the band-shaped high-voltage electrode, respectively, in a fragmentary manner along the band plate longitudinal direction, and alternately with the front and back. A discharge space is formed between the electrodes by using a plurality of slit-shaped gas blowout holes that are arranged and configured to be able to blow out a gas stream containing a chemically active excited species in a substantially linear manner. Compared to conventional general plasma generators, not only can the structure of the electrodes be simplified and the production cost can be greatly reduced, but also the plasma loss can be reduced by reducing the discharge loss associated with abnormal discharges such as sparks and arc discharges. It tends to stabilize the generation can be performed well appropriate and efficient the one surface treatment by plasma.

Further, as a plasma generator used in the continuous plasma processing / surface processing method, a flat high-voltage electrode and a large number of gas flow ejection holes are formed on the entire surface of the flat plate. A discharge part consisting of a minute gap is formed between the two electrodes by opposing the ground electrode with an insulator interposed. A glow discharge plasma is generated by the supply of a high-frequency voltage to both electrodes and generated in the minute gap. The gas flow containing the chemically active excited species may be ejected from a number of gas ejection holes of the ground electrode. In this case, the damage caused by directly exposing the surface of the processing object to ions, electrons, and the like contained in the plasma is reduced, and the activity of the neutrally excited species effective for the surface treatment is not impaired. In the meantime, it is possible to perform reliable and efficient plasma treatment by irradiating one surface of the object to be processed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a continuous plasma processing / surface processing method according to the present invention.
FIG. 2 is a conceptual diagram of a system used when performing a method of continuously performing surface processing and drying, and FIG. 2 is a schematic diagram of the system configuration.

[0010] This continuous plasma treatment / surface treatment /
The drying system is configured to transfer the sheet-like workpiece S along the transport path of the transport device 1 such as a belt conveyor that continuously places and transports the sheet-like workpiece S from the upper side to the lower side of the transport. An atmospheric pressure plasma generator 2 for performing a plasma treatment (A) such as modifying one surface Sa of the hydrophobic surfaces to hydrophilicity or imparting wettability to the surface; A surface processing apparatus 3 for performing a predetermined processing (B) such as printing, painting, applying an adhesive, dyeing, or grafting on one surface Sa of the workpiece S.
And a high-frequency dielectric heating and drying device 4 for heating and drying the surface Sa of the workpiece S after the surface processing.

The atmospheric pressure plasma generator 2 includes:
For example, as shown in FIG. 3 to FIG. 5, the high voltage electrode 20 formed in a solid band plate shape is electrically isolated on both sides in the thickness direction of the high voltage electrode 20 through band insulators 21. A pair of strip-shaped ground electrodes 22 that are grounded and formed between the high-voltage electrode 20 and the ground electrode 22 at one end of the high-voltage electrode 20, the ground electrode 22, and the insulator 21 in the width direction of the strip. The corner U is formed so as to surround the whole except the discharge part 23.
A helium gas or an inert gas containing hydrogen and an oxygen or fluorine-containing compound (a helium gas or a hydrogen-containing compound) are formed in a reaction gas supply passage 25 formed in the solid inside of the high-pressure electrode 20. A mixed gas with a reactive gas containing a fluorocarbon-based gas is supplied under atmospheric pressure, and the mixed gas is introduced into a discharge unit 23 and a high-frequency power (10 KHz to 500 MH) is applied to the high-voltage electrode 20.
By supplying z), a glow discharge plasma is generated under atmospheric pressure in the discharge unit 23, and the plasma generates a reactive gas flow containing chemically active excited species such as ions and radicals. The gas flow is arranged on both the front and back surfaces at one end side in the plate width direction of the solid band plate-shaped high-voltage electrode 20 in a fragmentary manner along the band plate longitudinal direction, and partly wrapped alternately on the front and back sides. A plurality of substantially semicircular slit-shaped gas blowing holes 26 formed in such a manner that the gas can be ejected in one direction, that is, substantially linearly toward one surface Sa of the processing object S is used. are doing.

Further, the high-frequency dielectric heating and drying apparatus 4 comprises:
As shown in FIG. 2, a plurality of roll-shaped electrodes 40 are arranged in parallel with each other at predetermined intervals in the transport direction of the workpiece S, and one of these roll-shaped electrodes 40 is arranged in the transport direction. By supplying high-frequency power between a plurality of pairs of positive and negative electrodes 40a and 40b adjacent to each other in the transport direction with the electrode 40a located at every other position as a positive electrode and the other electrode 40b as a negative electrode, Heat is generated in the object S, and the heat is subjected to predetermined processing such as printing, painting, application of an adhesive, dyeing, or grafting by the surface processing apparatus 3 to be processed S.
Is applied to the surface Sa, and the surface Sa is heated and dried.

In the system having the above configuration, the high-frequency power generated by the single high-frequency power supply 5 of several tens of MHz is applied to the high-voltage electrode 20 of the plasma generator 2 and the roll-shaped electrode 40 of the high-frequency dielectric heating and drying apparatus 4. The divider 6 divides the power by a predetermined ratio in the range of 50% / 50% to 5% / 95%, and supplies the divided power through the matching devices 7 and 8, respectively.

In the continuous plasma processing / surface processing / drying system configured as described above, even if no pre-processing such as application of a plasma processing inhibitor to the other surface Sb of the workpiece S is performed, The object S is conveyed continuously or intermittently along a certain conveyance path via the conveyance device 1. First, the object S is generated by glow discharge plasma generated by the discharge unit 23 in the atmospheric pressure plasma generator 2. Then, a gas flow containing a chemically active excited species which is ejected in a substantially straight line from the plurality of slit-shaped gas ejection holes 26 in one direction is applied to one surface S of the workpiece S.
a to be irradiated, whereby the object S
Is subjected to a plasma treatment (A) such as hydrophilicity modification on one surface Sa. Subsequently, a predetermined surface processing (B) such as printing, painting, applying an adhesive, or grafting is performed on one surface Sa of the workpiece S after the plasma processing such as the modification by the surface processing apparatus 3. After that, a series of processes are continuously and simultaneously performed in such a manner that the surface Sa of the processing object S is dielectrically heated and dried (C) by the high frequency dielectric heating and drying device 4. Thus, the overall processing speed is increased, and the productivity can be improved.

Here, each electrode 20 of the atmospheric pressure plasma generator 2 and the high-frequency dielectric heating and drying apparatus 4 used for plasma processing for printing, painting, grafting, etc.
And 40, a high-frequency power generated by a single high-frequency power supply 5 is divided by a high-frequency power divider 6 at a predetermined ratio, and the divided power is supplied through matching devices 7 and 8, respectively. As a result, compared to a case where both devices 2 and 4 are individually equipped with a high-frequency power supply,
As well as reducing the equipment cost of the entire system,
The space required for installation can be reduced and the energy consumption can be reduced by simultaneously performing both processes. In addition, by matching the load impedance and the supply impedance in each of the two devices 2 and 4, the predetermined plasma process and the heating and drying process can be performed appropriately and stably. It is possible to do.

In the above-described embodiment, the plasma generator 2 having the configuration as shown in FIGS. 3 to 5 is used. Instead, the plasma generator 2 is configured as shown in FIGS. 6 and 7. A flat plate type atmospheric pressure plasma generator 2 ′ may be used.

The flat-plate type atmospheric pressure plasma generator 2 'shown in FIGS. 6 and 7 has a high-voltage electrode 20 formed in a rectangular plate shape.
', And a large number of gas flow ejection holes 26' on the entire surface of a rectangular flat plate.
Is punched, and a stainless steel punching metal or the like is disposed opposite the high-voltage electrode 20 ′ with a thin rectangular annular insulator 21 ′ interposed therebetween so as to form a discharge portion 23 ′ having a minute gap with the high-voltage electrode 20 ′. Ground electrode 22 '
And a thin annular portion 27a for securing a minute gap to serve as a discharge portion 23 'is formed in a paragraph shape on the inner peripheral side of the high voltage electrode 20'. The ground electrode 22 'is connected to the high voltage electrode 20' via an inner gas ring 28 made of an insulating material at the center thereof. A fixing jig 29 to be fixed, and the other of the rectangular annular insulator 30 and the high-voltage electrode 20 ′ arranged on the outer peripheral surface of the high-voltage electrode 20 ′ except for the discharge portion 23 ′ and the outer peripheral portion of the rectangular outer gas ring 27. Insulator 31 in contact with the surface of
And a cover casing 24 'made of aluminum or the like which surrounds the entirety of the first and second parts 0, 31.

In the solid inside of the high-voltage electrode 20 ', one end is opened on the surface on the side different from the side on which the discharge portion 23' is formed, and the other end is connected to the outer gas ring 27 and the inner gas ring 28, respectively. One end of each of the formed rectangular annular grooves 32 and 33 is connected in an open state, and an inert gas and a reactive gas containing oxygen or a fluorine-containing compound (fluorocarbon) gas supplied from one end of the opening at atmospheric pressure. The reaction gas supply passages 25 'and 25' for introducing the mixed gas into the rectangular annular grooves 32 and 33 are formed through. Further, the outer gas ring 27 is provided with a plurality of slit-shaped gas supply holes 34A for ejecting the mixed gas from the outer periphery of the minute gap toward the center in the direction of arrow a in FIG. A plurality of slit-shaped gas supply holes 34B for ejecting the mixed gas in the direction of arrow b in FIG.
Are formed in the slit-shaped gas supply holes 34.
The mixed gas is supplied from A and 34B to the minute gap which becomes the discharge part 23 'in the state of the inside and outside counterflow, respectively.

When the flat-plate type atmospheric pressure plasma generator 2 'having the above structure is used in place of the atmospheric pressure plasma generator 2 shown in FIGS. Also, as in the above-described embodiment, the plasma processing and the surface processing on one surface Sa of the processing object S can be performed very efficiently to improve the productivity.

In the flat type atmospheric pressure plasma generator 2 'shown in FIG. 6 and FIG.
And the slit-shaped gas supply holes 34A and 34B formed in the inner gas ring 28, respectively, to supply the mixed gas to the minute gap in a state of counterflow between the inside and the outside, but without the inner gas ring 28. A flat atmospheric pressure plasma generator 2 ′ configured to supply a mixed gas only from the slit-shaped gas supply holes 34 A formed in the outer gas ring 27 may be used.

[0021]

As described above, according to the present invention, a plasma capable of linearly ejecting a gas flow containing a chemically active excited species generated along with the generation of a glow discharge plasma in one direction. By using the generator, it is possible to remove the object to be processed without having to perform a complicated and time-consuming operation such as applying a treatment inhibitor in advance to the surface of the object that does not require plasma processing. Plasma processing only on one surface of the object to be processed and predetermined processing such as printing, painting or grafting on the surface after the plasma processing, simply by continuously transporting along a certain transport path via the transport device Can be performed continuously and simultaneously on a plurality of workpieces. Therefore, not only can the applicability to a wide variety of workpieces having different thicknesses, shapes, and the like be improved, but also the efficiency of predetermined plasma processing and surface processing on only one surface of the workpiece can be increased to significantly increase productivity. There is an effect that improvement can be achieved.

In particular, the present invention relates to a plasma generating apparatus.
Alternatively, in addition to the above-mentioned effects, the use of the configuration as described in claim 3 reduces the discharge loss associated with abnormal discharge such as spark or arc discharge, stabilizes the generation of plasma, The surface treatment can be performed reliably, appropriately, and more efficiently.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a system used as an example of a continuous plasma processing / surface processing method according to the present invention when performing a method of continuously performing plasma processing / surface processing / drying.

FIG. 2 is a schematic diagram of a system configuration according to the first embodiment;

FIG. 3 is a side view of a plasma generator in the same system.

FIG. 4 is a bottom view of the plasma generator.

FIG. 5 is a vertical sectional front view of the plasma generator.

FIG. 6 is a vertical sectional side view of a plasma generator according to another embodiment of the present invention.

FIG. 7 is a half-cross-sectional bottom view of the plasma generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conveying apparatus 2, 2 'Atmospheric-pressure plasma generator 3 Surface processing apparatus 20, 20' High-voltage electrode 21, 21 'Insulator 22, 22' Ground electrode 23, 23 'Discharge part 26 Slit-shaped gas blowing hole 26' gas Outflow hole S Object to be treated Sa Surface to be treated

Continued on the front page F term (reference) 4F073 AA01 BA03 BA07 BA08 BA16 BB09 CA01 CA07 CA08 CA14 CA62 CA65 CA67 4L031 CB05 DA00 DA08 DA21

Claims (3)

[Claims] An inert gas containing at least helium or hydrogen and oxygen or a fluorine-containing compound (fluorocarbon) in a discharge portion formed between a high-voltage electrode and a ground electrode.
A mixed gas with a reactive gas containing a gas is introduced and passed at atmospheric pressure or a pressure close to atmospheric pressure, and a high-frequency power is supplied to the two electrodes to generate glow discharge plasma in the discharge part, thereby causing chemical discharge. A gas stream containing a highly active excited species is generated, and the gas stream ejected from a plasma generator capable of directing the gas stream in one direction is continuously or almost continuously emitted by a carrier. By irradiating one surface of the conveyed sheet-shaped object to be processed, one surface of the object to be processed is plasma-processed in a plane, and then a predetermined surface is applied to one surface of the plasma-processed object. Continuous plasma processing characterized by processing
Surface processing method. 2. The plasma generating apparatus according to claim 1, further comprising: a solid band-shaped high voltage electrode; and ground electrodes disposed on both sides in the thickness direction of the band-shaped high voltage electrode with an insulator interposed therebetween. A plurality of slit-shaped gas blowing holes are formed on both front and back surfaces at one end side in the width direction of the plate-like high-voltage electrode in a fragmentary manner along the longitudinal direction of the strip, and are alternately arranged on the front and back sides. 2. The continuous plasma processing / surface processing method according to claim 1, wherein the gas flow including the active excited species is configured to be ejected in a substantially linear manner. 3. A plasma generating apparatus as claimed in claim 1, wherein a flat high-voltage electrode and a flat ground electrode having a large number of gas flow ejection holes on the entire surface thereof are opposed to each other with an insulator interposed therebetween. Is formed, and a gas flow containing a chemically active excited species generated in a minute gap with the generation of a glow discharge plasma by supplying a high frequency voltage to both electrodes is formed by a large number of the ground electrodes. 2. The continuous plasma processing / surface processing method according to claim 1, wherein the method is configured to be able to eject gas from a gas jet hole.