JP4865208B2 - Atmospheric pressure plasma processing equipment - Google Patents

Description

  The present invention relates to an open-system atmospheric pressure plasma processing apparatus.

  Conventionally, there has been proposed a method of performing surface treatment on a substrate by using plasma that is stable under atmospheric pressure (so-called atmospheric pressure plasma) (for example, Japanese Laid-Open Patent Publication No. 1-305569 (Patent Document 1), Japanese Laid-open Patent Publication No. 2). -15171 (Publication 2). These surface treatment methods do not require a vacuum device or the like as compared with low-pressure plasma, and can be incorporated into a transport system such as a production line. It has been extended to surface treatment of organic films.

  When the processing apparatus is an open system in order to utilize the advantages of the atmospheric pressure plasma, the processing gas flows out of the processing apparatus or the outside air flows into the processing apparatus. Furthermore, the problem that the usage-amount of process gas increases in connection with it occurs. Therefore, for example, in the glow discharge plasma processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-142298 (Patent Document 3), a processing chamber and a storage chamber for storing the processing chamber are provided to process the pressure in the storage chamber. There has been proposed a method for preventing the outflow of the processing gas to the outside of the processing apparatus and the mixing of outside air into the processing chamber by setting the pressure lower than that of the processing chamber.

  However, in the conventional glow discharge plasma processing apparatus disclosed in Patent Document 3, since the processing gas used in the processing chamber flows out to the storage chamber, the amount of processing gas used increases. There's a problem. Furthermore, when a large air flow that cannot be absorbed in the storage chamber flows from the opening of the processing apparatus, there is a problem that it is not possible to prevent the outside air from flowing into the processing chamber.

  In the manufacturing process of LSIs (Large Scale Integrated Circuits) and liquid crystal displays, there is an airflow that flows downward from the ceiling, called downflow, in order to increase the cleanliness of the room. Therefore, when the glow discharge plasma processing apparatus disclosed in Patent Document 3 is used in the manufacturing process, it may be affected by the downflow. In the manufacturing process of the liquid crystal display, the downward air flow in the room hits the upper surface of the glass substrate and changes the flow in the transport direction, so that a large amount flows into the processing apparatus from the opening of the processing apparatus.

Further, when the transport mechanism for the substrate to be processed is incorporated in the processing apparatus, the surrounding gas is caught and flows into the processing unit by the operation of the transport mechanism, for example, rotation of the transport roller. It will be. Therefore, particularly when helium that is easy to diffuse is used as a processing gas, there is a problem that the processing gas concentration in the processing section may easily change and adversely affect the processing of the substrate. .
JP-A-1-306569 Japanese Laid-Open Patent Publication No. 2-15171 JP 2003-142298

  Accordingly, an object of the present invention is to provide an open atmospheric pressure plasma processing apparatus that can prevent the inflow of outside air, prevent the outflow of processing gas and gas generated in the processing process, and reduce the amount of processing gas used. There is.

In order to solve the above problems, the atmospheric pressure plasma processing apparatus of the present invention is:
An electric field is applied between a pair of electrodes that are coated with a solid dielectric and arranged at a predetermined interval, and a substrate to be processed is processed under atmospheric pressure by plasma generated between the electrodes. A plasma processing unit;
A processing gas supply means for supplying a processing gas between the electrodes in the plasma processing unit;
While housing the plasma processing unit and the processing gas supply means, a housing having an inlet of the substrate to be processed and an outlet of the substrate to be processed;
A substrate-to-be-processed conveying means that is accommodated in the housing and conveys the substrate to be treated from the inlet toward the outlet;
The housing is provided in at least the upper part of the upper and lower parts of the substrate to be processed in the vicinity of the inlet and outlet of the substrate to be processed, on the substrate side and on the inlet side And a gas curtain member that ejects gas in a curtain shape across the width direction of the substrate to be treated obliquely toward the outlet side,
The plasma processing unit includes a first plasma processing unit provided with one of the pair of electrodes and a first processing gas supply unit that supplies a processing gas from the one side between the electrodes, and the pair of electrodes. A second plasma processing section provided with the other of the electrodes, and a second processing gas supply means for supplying a processing gas from the other side between the electrodes,
The first plasma processing unit is installed approximately in the middle of the transport direction of the substrate to be processed on the first base housed in the housing, while the second plasma processing unit is opposed to the first base. And is installed in the middle of the transport direction of the substrate to be treated in the second base housed in the housing, and by changing the position of at least one of the first base and the second base , The distance between the pair of electrodes can be adjusted,
The substrate-to-be-treated transporting means is mounted on a base located on the lower side of the first base and the second base, and the base supports 2 the shaft of the substrate-to-be-treated transporting means. The support base that supports the shaft support roller is fixed,
The housing is provided with an exhaust port for exhausting the internal gas including the treated gas ,
The first processing gas supply means is arranged to supply the processing gas from the inlet side and the outlet side of the substrate to be processed rather than the one electrode, while the second processing gas supply means is It is arranged to supply the processing gas from the inlet side and the outlet side of the substrate to be processed rather than the other electrode,
The length of the substrate to be treated in the transport direction is longer than the length between the inlet and the outlet in the casing .

  According to the above configuration, at least near the substrate to be processed in the vicinity of the entrance / exit of the substrate to be processed in the housing, toward the substrate to be processed and obliquely toward the entrance / exit, Outflow of the processing gas from the casing and inflow of outside air into the casing can be prevented by the gas ejected in a curtain shape across the width direction of the substrate to be processed. Therefore, the amount of the processing gas used can be reduced even when the substrate to be processed is transported. Further, the discharge is not unstable due to the inflow of the outside air, and stable plasma can be obtained.

Furthermore, a first plasma processing unit provided with one of the pair of electrodes is installed on a first base, and a second plasma processing unit provided with the other of the pair of electrodes is connected with the first base. The distance between the pair of electrodes is adjustable by installing the second base on the opposite side and changing the position of at least one of the first base and the second base. Therefore, the distance between the pair of electrodes can be easily adjusted.

Further, the substrate-to-be-treated transporting means is mounted on a base positioned on the lower side of the first base and the second base, and the base of the base-material transporting means 2 is supported on the base. A support base for supporting the shaft support roller of the book is fixed. Accordingly, the shaft of the substrate to be processed is supported from the lower side by the two shaft supporting rollers so as not to bend, and there is no bending even when the large substrate to be processed is conveyed. A highly accurate transport mechanism can be realized.

In the atmospheric pressure plasma processing apparatus of one embodiment,
The gas ejection angle from the gas curtain member is 20 ° or more and 60 ° or less with respect to the surface of the substrate to be treated.
The flow rate of the gas is equal to or greater than the inflow amount of outside air from the inlet and outlet of the substrate to be processed when the gas is not ejected.

  According to this embodiment, the ejection angle of the gas with respect to the surface of the substrate to be treated is 20 ° or more. Accordingly, it is possible to reduce the amount of the outside air flowing from the inlet / outlet of the substrate to be processed and the amount of leakage of the processing gas. Further, the ejection angle is 60 ° or less. Accordingly, it is possible to reduce the amount of the jetted gas flowing into the plasma processing unit. Furthermore, since the flow rate of the gas is equal to or greater than the outside air inflow amount from the inlet / outlet of the substrate to be treated, the inflow of the outside air can be prevented more reliably.

In the atmospheric pressure plasma processing apparatus of one embodiment,
To-be-processed substrate transport means for transporting the to-be-treated substrate from the entrance of the to-be-processed substrate in the housing toward the exit of the to-be-processed substrate;
Isolation means for isolating the contact portion with the substrate to be processed and the portion other than the periphery of the contact portion of the substrate to be processed from the conveyance path of the substrate to be processed.

  According to this embodiment, the isolating means prevents the airflow generated by the carrying operation by the treated substrate carrying means from flowing into the carrying path of the treated substrate. Therefore, the concentration of the processing gas in the plasma generation region formed between the electrodes in the transfer path can be prevented from adversely affecting plasma generation.

In the atmospheric pressure plasma processing apparatus of one embodiment,
The flow rate at the exit of the process gas supply slit in the process gas supplied from the process gas supply means is 0.7 times or more the transport speed of the substrate to be processed.

  According to this embodiment, the concentration of the processing gas in the plasma generation region temporarily decreases due to the outside air entering from the entrance / exit of the substrate to be processed in the housing, and the discharge becomes unstable. Can be prevented.

In the atmospheric pressure plasma processing apparatus of one embodiment,
The processing gas supply means supplies the processing gas from a total of four locations on the inlet side and outlet side of the substrate to be processed rather than the electrodes in the pair of solid dielectrics covering the pair of electrodes. Arranged to be able to.

  According to this embodiment, even if the turbulence of the air flow in the plasma generation region occurs on the upstream side or the downstream side of the electrodes in the transport direction of the substrate to be processed, the processing gas is generated in the plasma. The region can be supplied and the plasma becomes stable.

In the atmospheric pressure plasma processing apparatus of one embodiment,
The processing gas is a gas containing helium.

  According to this embodiment, even when a gas containing helium that is easily diffused is used as the processing gas, the concentration of the processing gas in the plasma generation region changes due to the ingress of outside air, and plasma generation occurs. Can be adversely affected.

  As is clear from the above, the atmospheric pressure plasma processing apparatus of the present invention is at least above the substrate to be processed in the vicinity of the entrance / exit of the substrate to be processed in the housing, facing the substrate to be processed and the above-mentioned Since the gas curtain member that blows out the gas in the form of a curtain across the width direction of the substrate to be treated is provided obliquely toward the entrance / exit side, the gas to be ejected is transported by the gas to be treated. However, the outflow of the processing gas from the housing and the inflow of outside air into the housing can be prevented. Therefore, the amount of the processing gas used can be reduced. Furthermore, it is possible to prevent adverse effects on plasma generation due to changes in the concentration of the processing gas in the plasma generation region formed between the electrodes due to the inflow of the outside air.

  As described above, according to the atmospheric pressure plasma processing apparatus of the present invention, it is possible to perform plasma processing under atmospheric pressure even in a space where an air flow such as downflow exists. Therefore, it can be easily inlined even in a clean room, and the speed of the entire manufacturing process of a liquid crystal display or the like can be improved.

Furthermore, a first plasma processing unit provided with one of the pair of electrodes is installed on a first base, and a second plasma processing unit provided with the other of the pair of electrodes is connected with the first base. Since the distance between the pair of electrodes can be adjusted by installing at the opposite second base and changing the position of at least one of the first base and the second base, the distance between the pair of electrodes can be simplified. Can be adjusted.

Further, the substrate-to-be-treated transporting means is mounted on a base positioned on the lower side of the first base and the second base, and the base of the base-material transporting means 2 is supported on the base. Since the support base for supporting the shaft support rollers is fixed, the shaft of the substrate transporting means is supported from below by the two shaft support rollers so as not to bend. A high-accuracy conveyance mechanism without bending can be realized for conveyance of the substrate to be processed.

  Further, the atmospheric pressure plasma processing apparatus of the present invention comprises an isolating means for isolating a portion excluding the vicinity of a contact portion with the target substrate in the target substrate transport means for transporting the target substrate from the transport path. If provided, it is possible to prevent the airflow generated by the transport operation by the substrate-to-be-processed transporting unit from flowing into the transport path of the substrate to be processed. Therefore, it is possible to more effectively prevent the adverse effect on the plasma generation.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a schematic cross-sectional view of the atmospheric pressure plasma processing apparatus of the present embodiment. 2 to 4 are schematic views showing the main structure of the atmospheric pressure plasma processing apparatus shown in FIG. It should be noted that the present invention is not limited to the structure shown in FIGS. 1 to 4 without departing from the spirit of the present invention.

  In FIG. 1, reference numeral 1 denotes a plasma processing unit, which is composed of two parts, an upper part 1a and a lower part 1b that face each other with a substrate 6 to be processed interposed therebetween. And the upper part 1a and the lower part 1b have the same structure except that the structure is the object for the substrate 6 to be treated, and each part 1a, 1b is an electrode 2 covered with a solid dielectric. And a processing gas reservoir space 3 and a processing gas supply slit 4 which is provided in the solid dielectric and communicates with the processing gas reservoir space 3 and the outside of the substrate 6 to be processed. In the above configuration, the substrate 6 to be treated is treated with the plasma 5 generated by the discharge between the electrode 2 provided on the upper part 1a and the electrode 2 provided on the lower part 1b.

  That is, in the present embodiment, the processing gas supply means is constituted by the upper portion 1a and the lower portion 1b, the processing gas reservoir space 3, and the processing gas supply slit 4.

  The processing gas reservoir space 3 is provided in order to supply gas uniformly in the width direction of the substrate 6 to be processed (the direction perpendicular to the traveling direction of the substrate 6 to be processed indicated by the arrow (A)). If there is a similar effect, other means may be used. In the discharge, the processing gas 7 in the processing gas reservoir space 3 is introduced between the electrodes 2 and 2 through the processing gas supply slit 4 and an AC voltage is applied between the power source 8 and the electrodes 2 and 2. It is a glow discharge caused by this. Reference numerals 9 and 10 denote bases that support the solid dielectrics of the upper part 1a and the lower part 1b of the plasma processing unit 1. The upper part 1a is installed on the base 9, while the lower part 1b is installed on the base 10. The distance between the electrodes 2 and 2 can be adjusted by changing the position of at least one of the base 9 or the base 10 and adjusting the distance H1 (see FIG. 4) between the upper part 1a and the lower part 1b. Yes.

  Gas curtain members 12 having gas reservoir spaces 11 are installed on both ends of the base 9 across the upper portion 1a of the plasma processing unit 1, and each gas curtain member 12 is obliquely downward from the gas reservoir space 11. A gas curtain supply slit 13 is provided so as to lead the gas reservoir space 11 to the outside from the corner of the gas curtain member 12 on the substrate 6 to be processed side and on the anti-plasma processing unit 1 side. Thus, the gas 14 can be ejected from the gas reservoir space 11 to the outside of the apparatus through the gas curtain supply slit 13.

  The gas 14 is a clean gas free from particles and moisture. The gas reservoir space 11 is provided so that the gas 14 flows uniformly from the gas curtain supply slit 13 in the width direction of the substrate 6 to be processed. You may use. For example, there is a method of installing a nozzle provided with ejection openings at regular intervals in a steel pipe on the upstream side of the gas curtain supply slit 13. Hereinafter, as described above, the gas 14 injected in a curtain shape through the gas curtain supply slit 13 may be referred to as a “gas curtain”.

  A space is provided in the base 10 so that the shaft 16 provided in the base material conveyance roller 15 can pass through. And the space | interval and base material which block | close with the board | plate material 17 except the vicinity of the location where the base material conveyance roller 15 in the surface at the side of the base material 6 in the base 10 contacts with the base material 6 are passed. It is blocked from the transfer space.

  The base 9 and the base 10 having the above-described configuration are covered with a casing 18, and the casing 18 is provided with a plurality of exhaust ports 19 for exhausting the processed gas. Portions 20 and 20 are provided. In addition, when the width | variety of the to-be-processed base material 6 exceeds 1 m, it is desirable to install two or more exhaust ports 19 in the width direction at intervals of 20 cm to 80 cm.

  The gas curtain members 12, 12 installed in the vicinity of the openings 20, 20 in the atmospheric pressure plasma processing apparatus (hereinafter sometimes simply referred to as the present apparatus) are the gas curtains 14 ejected from the gas curtain member 12. The effect of confining the processing gas 7 in the space formed by the flow and the apparatus, the outside air guided along the substrate 6 to be conveyed and the downflow in the clean room hit the substrate 6 to be opened. There are two effects, that is, the effect of preventing the inflow of outside air (hereinafter collectively referred to as outside air 21) toward the section 20.

  As described above, the gas 14 is ejected from the gas curtain member 12 at a certain angle with respect to the surface of the substrate 6 to be processed. This angle is preferably 20 ° or more and 60 ° or less, although it depends on the shape of the apparatus. When the angle is larger than 60 °, the amount of the injected gas 14 flowing into the plasma processing unit 1 increases and 20 ° If it becomes smaller, the inflow amount of the outside air 21 and the leakage amount of the processing gas 7 from the inside of the housing 18 increase. In the present embodiment, as shown in FIG. 1, the gas curtain member 12 is installed above the transport path of the substrate 6 to be processed. However, when the outside air 21 is mixed from below the substrate 6 to be treated, it may be installed on both upper and lower sides of the transport path.

  In addition, although the conveyance method by roller conveyance was shown about conveyance of the said to-be-processed base material 6, in the case of normal roller conveyance, generation | occurrence | production of the airflow 22 by the rotation of the shaft of a roller for conveyance, and generation | occurrence | production of the bending of the said shaft. Causes the following problems.

  That is, the air flow 22 generated by the rotation of the shaft becomes an air flow in the transport direction of the substrate 6 to be processed inside the housing 18. Therefore, a flow path through which the outside air 21 flows into the discharge portion is formed, and the concentration of the processing gas 7 in the plasma generation region changes, which adversely affects plasma generation.

  As for the bending of the shaft, the height of the transport path (that is, the distance between the base 9 and the base 10) and the distance between the electrodes 2 and 2 are increased by the amount of displacement of the central axis due to the bending. The reason is that the substrate 6 to be processed is bent and conveyed by the bending of the shaft, and in this case, in order to avoid the substrate 6 to be in contact with the discharge part, the electrode 2 and the electrode 2 are separated. This is because the interval of is widened. Therefore, in that case, the conductance with respect to the gas flow along the upper surface of the substrate 6 to be processed in the transport path is increased, and the outside air 21 easily flows. Therefore, similarly to the case of the air flow 22 generated by the rotation, the discharge is adversely affected.

  Therefore, in this embodiment, a plate material 17 is installed on the shaft 16 of the base material conveyance roller 15 in the base 10, and the conveyance of the air flow 22 generated by the rotation of the shaft 16 by the plate material 17. The inflow to the route is prevented. Specifically, as shown in FIG. 2, the entire shaft 16 extending in the width direction of the substrate to be processed 6 excluding the vicinity of the portion where the substrate conveying roller 15 contacts the substrate to be processed 6 is made of a plate material. 17 is covered. The plate material 17 is preferably made of a material that is highly durable against plasma, ultraviolet rays, and the like.

  That is, in the present embodiment, the base 10 and the plate material 17 constitute the isolation means.

  Further, with respect to the bending of the shaft 16, both ends are supported at appropriate positions (for example, the central portion) in the extending direction of the shaft 16 by the support base 24 fixed to the base 10 as shown in FIG. The shaft 16 is supported from below by the two shaft support rollers 23 and 23 so that the shaft 16 is not bent. In this case, the base 10 needs to be strong enough not to bend even if the shaft 16, the shaft support roller 23, and the support base 24 are supported. Thus, it is possible to realize a highly accurate transport mechanism without bending even when transporting the large substrate 6 to be processed by roller transport. It should be noted that a transport method other than the roller transport may be used as long as it does not disturb the airflow in the transport path and increases the height of the transport path. For example, there is conveyance by a conveyor using a material excellent in plasma resistance for a belt.

  The introduction of the processing gas 7 into the generation region of the plasma 5 is such that the flow velocity in the vicinity of the plasma 5 (that is, the outlet of the processing gas supply slit 4) is 0.7 times or more the conveying speed of the substrate 6 to be processed. More preferably, it is carried out so that it becomes 0.8 times or more. This is because when the flow rate of the processing gas 7 to be supplied is slower than 0.7 times the transport speed, the processing gas in the plasma generation region is caused by the outside air 12 entering along with the transport of the substrate 6 to be processed. This is because the concentration of 7 temporarily decreases and discharge becomes unstable.

  FIG. 4 is an enlarged cross-sectional view of the electrodes 2 and 2 in the upper part 1a and the lower part 1b of the plasma processing unit 1. As shown in FIG. The process gas 7 may be supplied from two process gas supply slits provided in the vicinity of the electrode 2 in the upper part 1a and in the vicinity of the electrode 2 in the lower part 1b. More preferably, as shown in FIG. In the vicinity of the upper electrode 2a, which is the electrode 2 of 1a, with respect to the transport direction of the substrate 6 to be treated, both the upstream and downstream sides of the upper electrode 2a, and the lower portion of the lower electrode 2b, which is the electrode 2 of the lower 1b It is preferable to supply from a total of four process gas supply slits 4 provided on both sides of the electrode 2b. By doing so, the process gas 7 is supplied to the plasma generation region regardless of whether the turbulence in the plasma generation region occurs on the upstream side or the downstream side of the electrode a in the transport direction of the substrate 6 to be processed. The plasma becomes stable.

  In FIG. 4, the distance between the upper part 1a and the lower part 1b is "H1", and the distance between the upper part 1a and the upper surface of the substrate 6 to be processed is "H2". Is set to “H3”, and the width (interval) of the process gas supply slit 4 is set to “G”. The interval H1 between the upper portion 1a and the lower portion 1b and the interval H2 between the upper portion 1a and the upper surface of the substrate 6 to be processed are set by the amount of bending of the substrate 6 to be processed during conveyance. In order to reduce the conductance with respect to the gas flow along the upper and lower surfaces of the substrate 6, it is preferable to narrow the intervals H1 and H2 as much as possible.

  The width G of the process gas supply slit 4 is preferably as narrow as possible in order to increase the process gas supply speed. However, if unevenness occurs in the width G due to processing accuracy or adjustment method, the gas flow rate becomes non-uniform, so 0.1 mm or more, or 0.1% or more of the length of the electrode 2 in the traveling direction of the substrate 6 to be processed. Alternatively, it is preferably set to 0.01% or more of the length of the processing gas supply slit 4.

  The material of the solid dielectric 25 covering the upper electrode 2a and the lower electrode 2b is preferably a ceramic such as alumina. By doing so, it is possible to suppress deterioration of the electrode 2 due to long-time discharge and transition to abnormal discharge.

(Example)
The influence on plasma generation was confirmed under the following conditions by the atmospheric pressure plasma processing apparatus shown in FIG.
Electrode 2: 1520 mm x 23 mm
Solid dielectric 25: Alumina (Al ₂ O ₃ ) 99.5%
Power supply 8: Sin wave, 20 kHz
Applied voltage: ± 5kV
Process gas 7: Helium + clean dry air 2%
Process gas supply slit length: 1520mm
Process gas supply slit width G: 1.25 mm to 2.0 mm
Process gas supply rate: 30L / min to 50L / min
Spacing H1 between upper part 1a and lower part 1b: 5.5 mm
Spacing H2 between upper part 1a and substrate 6 to be treated: 2.3 mm
Interval H3 between lower part 1b and substrate 6 to be treated: 2.5 mm
Gas curtain 14: Clean dry air
Flow rate of gas curtain 14: 260L / min
Gas curtain spray angle: 45 °
Gas curtain supply slit 13: 1520mm x 0.5mm
Substrate 6: Glass substrate for liquid crystal panel
Size of substrate 6 to be treated: 1500mm x 1800mm x 0.7mm
Conveyance speed of substrate 6 to be treated: 4.5 m / min

  The amount of outside air 21 that flows into the apparatus when the downflow in the clean room hits the glass substrate for the liquid crystal panel is maximum when the top of the glass substrate to be conveyed is at the position of the opening 20 of the apparatus. Become. The inflowing outside air 21 becomes an air flow of 0.56 m / second to 0.70 m / second toward the inside of the apparatus. The inflow of the outside air 21 is 100 L / min to 128 L / min when converted from the shape of the opening 20 of the present apparatus. Therefore, it is desirable that the ejection flow rate of the gas curtain 14 is equal to or greater than the inflow amount of the outside air 21. On the other hand, in the opening 20 on the outlet side, there is an air flow toward the inside of the apparatus at a maximum of 0.46 m / sec to 0.61 m / sec.

  In the state where the airflow as described above exists, the processing gas 7 is supplied to the apparatus at a supply amount of 50 L / min, and a voltage is applied to the electrode 2 to carry the glass substrate. In that case, when the gas curtain 14 was not used, a state where no discharge occurred in a part of the discharge portion occurred. In contrast, when the gas curtain 14 was used under the same conditions as described above, the plasma state could be stably maintained even when the glass substrate was being conveyed.

  FIG. 5 shows the discharge state of plasma with respect to the conveyance speed of the glass substrate and the supply flow rate of the processing gas 7 when the gas curtain 14 is used. Here, the supply flow rate of the processing gas 7 is such that the supply amount of the processing gas 7 is changed to 30 L / min, 34 L / min, and 40 L / min, and the width G of the gas supply slit 4 is 1.25 mm, 1.5 mm, 1 It was changed by changing to .75 mm and 2.0 mm. FIG. 5 shows that the discharge stability of the plasma has a certain relationship between the conveyance speed of the glass substrate and the supply flow rate of the processing gas 7.

  That is, if the supply speed of the processing gas 7 is kept constant and the conveyance speed of the glass substrate is increased, the discharge stability of plasma deteriorates. Further, if the supply flow rate of the processing gas 7 is increased while keeping the glass substrate transport speed constant, the discharge stability of the plasma is improved. In addition, the supply flow rate of the processing gas 7 at the boundary between stable and unstable in plasma discharge increases as the conveyance speed of the glass substrate increases. When the process gas 7 is supplied at a flow rate of 75 mm / second or more, a stable discharge can be obtained at a glass substrate transfer speed of 50 mm / second to 100 mm / second.

  As can be seen from the above examples, if the atmospheric pressure plasma processing apparatus in the present embodiment is used, even if helium gas that is very diffusible is used as the processing gas 7, the outflow of the processing gas 7 can be prevented. It is possible to reduce the amount of gas used, that is, to reduce the cost. Therefore, it is easy to inline the apparatus.

  As described above, in the present embodiment, gas reservoir spaces 11 are provided at both ends of the upper part 1a of the base 9 that is disposed on the upper side of the substrate 6 and supports the upper part 1a of the plasma processing unit 1. A gas curtain member 12 is installed. Then, the gas curtain 14 is emitted from the gas reservoir space 11 through the gas curtain supply slit 13 obliquely downward from the corner of the gas curtain member 12 on the substrate 6 to be processed side and on the anti-plasma processing unit 1 side. I have to. Therefore, the processing gas 7 can be confined in the space formed by the flow of the gas curtain 14 and the present apparatus, and even if the processing gas 7 is easily diffused, the amount of use can be reduced. Further, the gas curtain 14 can effectively prevent the inflow of the outside air 21.

  That is, according to the present embodiment, even when the substrate 6 to be processed is being transported, a state where no discharge occurs in a part of the discharge portion is eliminated, and the plasma state can be kept stable. is there. The “helium gas” here is a concept including a gas containing helium.

  In this case, the emission angle of the gas curtain 14 from the gas curtain supply slit 13 is set to 20 ° or more and 60 ° or less. Therefore, the inflow of the outside air 21 and the leakage of the processing gas 7 can be prevented, and the inflow of the jetted gas 14 to the plasma processing unit 1 side can be suppressed.

  Further, a plate material 17 is provided on the base 10 on the shaft 16 of the base material transporting roller 15 so as to cover the portion except for the vicinity of the portion where the base material transporting roller 15 contacts the substrate 6 to be processed. ing. Therefore, the plate member 17 can prevent the air flow 22 generated by the rotation of the shaft 16 from flowing into the transport path, and can prevent the outside air 21 from flowing into the transport path and adversely affecting the discharge.

  Further, the shaft 16 is supported by the support base 24 and the shaft support rollers 23 and 23 fixed to the base 10 so that the shaft 16 is not bent. Accordingly, it is possible to prevent the outside air 21 from flowing into the transport path due to the bending of the shaft 16 and to prevent the discharge from being adversely affected.

It is a cross-sectional schematic diagram in the atmospheric pressure plasma processing apparatus of this invention. It is a figure which shows arrangement | positioning of the board | plate material in FIG. It is a figure which shows the shaft support roller which supports the shaft in FIG. It is an expanded sectional view of the electrode part in the plasma processing part in FIG. It is a figure which shows the relationship between the conveyance speed of a glass substrate at the time of using a gas curtain, the supply flow rate of a process gas, and a discharge state.

1 ... Plasma processing unit,
1a ... Upper part
1b ... Bottom,
2 ... Electrodes,
2a: upper electrode,
2b ... lower electrode,
3 ... Processing gas reservoir space,
4 ... Slit for supplying process gas,
5 ... Plasma,
6 ... treated substrate,
7 ... Processing gas,
8 ... Power supply,
9, 10 ... the foundation,
11 ... Gas reservoir space,
12 ... Gas curtain member,
13 ... Slit for gas curtain supply,
14 ... Gas curtain,
15 ... Roller for conveying the substrate,
16 ... shaft,
17 ... plate material,
18 ...
19 ... exhaust port,
20 ... opening,
21 ... Open air,
22 ... Airflow by shaft rotation,
23 ... Roller for shaft support,
24 ... support stand,
25: Solid dielectric.

Claims (6)

An electric field is applied between a pair of electrodes that are coated with a solid dielectric and arranged at a predetermined interval, and a substrate to be processed is processed under atmospheric pressure by plasma generated between the electrodes. A plasma processing unit;
A processing gas supply means for supplying a processing gas between the electrodes in the plasma processing unit;
While housing the plasma processing unit and the processing gas supply means, a housing having an inlet of the substrate to be processed and an outlet of the substrate to be processed;
A substrate-to-be-processed conveying means that is accommodated in the housing and conveys the substrate to be treated from the inlet toward the outlet;
The housing is provided in at least the upper part of the upper and lower parts of the substrate to be processed in the vicinity of the inlet and outlet of the substrate to be processed, on the substrate side and on the inlet side And a gas curtain member that ejects gas in a curtain shape across the width direction of the substrate to be treated obliquely toward the outlet side,
The plasma processing unit includes a first plasma processing unit provided with one of the pair of electrodes and a first processing gas supply unit that supplies a processing gas from the one side between the electrodes, and the pair of electrodes. A second plasma processing section provided with the other of the electrodes, and a second processing gas supply means for supplying a processing gas from the other side between the electrodes,
The first plasma processing unit is installed approximately in the middle of the transport direction of the substrate to be processed on the first base housed in the housing, while the second plasma processing unit is opposed to the first base. And is installed in the middle of the transport direction of the substrate to be treated in the second base housed in the housing, and by changing the position of at least one of the first base and the second base , The distance between the pair of electrodes can be adjusted,
The substrate-to-be-treated transporting means is mounted on a base located on the lower side of the first base and the second base, and the base supports 2 the shaft of the substrate-to-be-treated transporting means. The support base that supports the shaft support roller is fixed,
The housing is provided with an exhaust port for exhausting the internal gas including the treated gas ,
The first processing gas supply means is arranged to supply the processing gas from the inlet side and the outlet side of the substrate to be processed rather than the one electrode, while the second processing gas supply means is It is arranged to supply the processing gas from the inlet side and the outlet side of the substrate to be processed rather than the other electrode,
The atmospheric pressure plasma processing apparatus , wherein a length of the substrate to be processed in a conveyance direction is longer than a length between the inlet and the outlet in the casing . In the atmospheric pressure plasma processing apparatus according to claim 1,
The gas ejection angle from the gas curtain member is 20 ° or more and 60 ° or less with respect to the surface of the substrate to be treated.
The atmospheric pressure plasma processing apparatus, wherein a flow rate of the gas is equal to or greater than an outside air inflow amount from an inlet and an outlet of the substrate to be processed when the gas is not ejected. In the atmospheric pressure plasma processing apparatus according to claim 1,
To-be-processed substrate transport means for transporting the to-be-treated substrate from the entrance of the to-be-processed substrate in the housing toward the exit of the to-be-processed substrate;
An isolation means for isolating the contact portion with the substrate to be processed and a portion other than the periphery of the contact portion of the substrate to be processed from the conveyance path of the substrate to be processed. Atmospheric pressure plasma processing equipment. In the atmospheric pressure plasma processing apparatus according to claim 1,
The atmospheric pressure plasma processing apparatus characterized in that the processing gas supplied from the processing gas supply means has a flow rate at the outlet of the processing gas supply slit of 0.7 times or more the conveying speed of the substrate to be processed. . In the atmospheric pressure plasma processing apparatus according to claim 1,
The processing gas supply means supplies the processing gas from a total of four locations on the inlet side and outlet side of the substrate to be processed rather than the electrodes in the pair of solid dielectrics covering the pair of electrodes. An atmospheric pressure plasma processing apparatus, which is arranged to be able to perform. In the atmospheric pressure plasma processing apparatus according to claim 1,
The atmospheric pressure plasma processing apparatus, wherein the processing gas is a gas containing helium.

Images