JP5593138B2 - Plasma surface treatment apparatus and electrode structure thereof - Google Patents

Description

The present invention relates to a plasma surface treatment apparatus and an electrode structure thereof, and more specifically, a plasma surface treatment apparatus and a structure of an electrode for performing a surface treatment of an object to be treated using discharge plasma generated under a pressure near atmospheric pressure. About.

  An example of this type of plasma surface treatment apparatus is shown in FIG. This plasma surface treatment apparatus applies a high-frequency electric field to both electrodes a and b while introducing a predetermined processing gas c between opposing electrodes consisting of a voltage application electrode a and a ground electrode b, thereby forming a discharge space d between these electrodes. The discharge plasma is generated, and the discharge plasma is guided to the object to be processed W arranged outside the discharge space d to perform the surface treatment of the object to be processed (see, for example, Patent Document 1).

  By the way, in order to generate stable discharge plasma (perform dielectric barrier discharge) in the plasma surface treatment apparatus having such a structure, at least the electrode facing surfaces of the metal electrodes e of the voltage application electrode a and the ground electrode b are used. One (both in the illustrated example) must be covered with a dielectric. Further, in order to prevent abnormal discharge (arc discharge) between the metal electrode e and the workpiece W, it is necessary to cover the surface of the metal electrode e on the workpiece side with a dielectric (insulator). . Furthermore, it is necessary to prevent creeping discharge from the edge portion on the back surface of the metal electrode to the workpiece W.

  For this reason, in the conventional plasma surface treatment apparatus, each metal electrode e is housed in a container-like case formed of a solid dielectric such as ceramics, and the entire metal electrode e is covered with the solid dielectric. Has been proposed (see FIG. 8 of Patent Document 2). Specifically, the dielectric case includes a case main body f for housing the metal electrode e and a lid g attached to the back surface of the case main body f. The case body f is formed by cutting a concave groove for accommodating the metal electrode e in a columnar ceramic sintered product having a quadrangular cross section and closing both ends of the groove with a ceramic block or the like. Thus, a space for accommodating the electrode body e is formed.

JP 2002-237480 A JP 2004-128417 A

  However, the plasma surface treatment apparatus having such a conventional configuration has the following problems, and improvements have been desired.

(1) In the conventional electrode structure, the manufacturing cost of the dielectric case that accommodates the metal electrode e is high, and the manufacturing cost of the entire device is high.

  That is, when this type of dielectric case is manufactured by order production, the sintered ceramic material used as the material of the dielectric case is fragile, and cracking occurs when cutting is performed with high efficiency. Therefore, it takes a long time to form a groove having a depth sufficient to accommodate the metal electrode e without cracking, and the manufacturing cost of the case body f is high. .

  In this regard, it is conceivable to reduce the manufacturing cost of the case body f by manufacturing the case body f by bonding plate-shaped ceramics together. However, the metal electrode e ( In particular, the voltage application electrode a side) is heated to a high temperature by application of a high-frequency electric field, so that there is a possibility that the joint is peeled off due to the influence of this heat, and abnormal discharge (arc discharge or the like) from the peeled portion to the workpiece W occurs. There was a fear.

(2) In addition, in order to prevent creeping discharge from the metal electrode e to the object W to be processed, even if the periphery of the metal electrode e (particularly, the periphery of the top, bottom, left and right in FIG. 7) is covered with a dielectric, Since a joint portion is formed between the main body f and the lid g, even if the joint portion is sealed by adhesion or the like, a gap is generated in the joint portion due to aging or the like, and discharge is generated from the gap to the workpiece W. May happen.

  The present invention has been made in view of such problems, and its object is to realize a high performance by realizing an electrode structure that does not cause abnormal discharge to the object to be processed at low cost. Is to provide an inexpensive plasma surface treatment apparatus at a low cost.

In order to achieve the above object, the electrode structure according to the present invention has the following characteristics.
(1) In an electrode structure in which each electrode facing surface of a pair of electrodes arranged so as to form a discharge space is covered with a dielectric, a substantially plate-shaped solid dielectric is formed on each electrode facing surface of each electrode. A body plate is placed facing each other, and an electrode support stay for supporting each electrode is arranged on the side opposite to the electrode facing surface of each electrode. In this state, a liquid or gel-like dielectric is placed around each electrode. By filling and solidifying the electrodes, the electrodes are adhered to the solid dielectric plate disposed on the respective sides and the electrode support stay, and the periphery of each electrode is formed by the solid dielectric plate and the solidified dielectric. It is covered.

(2) Of the electrode support stays, at least the electrode support stays arranged on the electrode side to which a voltage is applied are made of an insulating material.

(3) The discharge formed between the solid dielectric plates by engaging at least one side of the peripheral portion of the solid dielectric plates with a member disposed adjacent to the solid dielectric plate. The width dimension of the space is specified.

The plasma surface treatment apparatus according to the present invention has the following characteristics in addition to the characteristics of the electrode structures (1) to (3).
(4) A discharge plasma obtained by applying a high-frequency electric field while introducing a processing gas into a discharge space formed between a pair of electrodes arranged opposite to each other is guided to an object to be processed disposed outside the discharge space. A plasma surface treatment apparatus for performing a surface treatment of an object to be processed, wherein the electrode support stay is fixed to a base member disposed so as to face the object to be processed, and a discharge formed on the base member The tip of each solid dielectric plate is fitted into the opening for plasma blowing.

(5) A gas introduction path for introducing the processing gas into the discharge space is formed at the joint by abutting the opposing surface at the end of each solid dielectric plate opposite to the object to be processed. A pair of gas introduction blocks are provided, and each of the gas introduction blocks is formed with an engagement portion that engages with the solid dielectric plate, and the engagement portion is provided on the object side of each solid dielectric plate. The width dimension of the discharge space formed between the solid dielectric plates is defined by engaging the opposite end.

(6) Each of the solid dielectric plates is set so that the end surface of the tip portion on the object side is substantially flush with the surface of the base member on the object side.

(7) Each of the pair of electrodes has an opposing surface parallel to the other electrode, and the cross-sectional shape of the end portion on the object side is thin.

  According to the electrode structure of the present invention, a substantially plate-shaped solid dielectric plate is disposed facing each electrode facing surface of a pair of electrodes disposed facing each other, and each electrode is disposed on the opposite side of the electrode facing surface of each electrode. An electrode support stay for supporting the electrode is arranged, and in this state, the electrode is configured by filling and solidifying a liquid or gel-like dielectric around each electrode. The only dielectric that requires cutting) is a substantially plate-shaped solid dielectric plate that is easy to process. Therefore, in the electrode structure of the present invention, the manufacturing cost of the electrode part can be suppressed at a low cost.

  In addition, since each electrode is bonded to a solid dielectric plate disposed on each side and an electrode support stay by filling and solidifying a liquid or gel dielectric around each electrode, the solid dielectric The plate, electrode, and electrode support stay can be firmly positioned, and an air layer causing corona discharge is not formed between the solid dielectric plate and the electrode, so that deterioration of the solid dielectric plate due to corona discharge is prevented. The In addition, since the periphery of each electrode is completely covered with the solid dielectric plate and the solidified dielectric, abnormal discharge (arc discharge, creeping discharge, etc.) from each electrode is also prevented.

  In addition, by forming an electrode support stay arranged on the electrode (voltage application electrode) side to which a voltage is applied among the electrodes from an insulating material, arc discharge occurs between the voltage application electrode and the electrode support stay. Can be prevented.

  According to the plasma surface treatment apparatus of the present invention, the electrode support stay is fixed to the base member disposed so as to face the object to be processed, and the discharge plasma blowing opening formed in the base member Since the tip of each of the solid dielectric plates is fitted to the plasma surface, by assembling the electrodes according to the shape of the base member (electrode support stay mounting position, opening forming position, etc.), the plasma surface The processing apparatus can be easily assembled.

  Further, a pair of gas introduction paths for introducing the processing gas into the discharge space is formed at the joint portion by abutting the opposing surface at the end of each solid dielectric plate opposite to the object to be processed. A gas introduction block is provided, and each of the gas introduction blocks is formed with an engagement portion that engages with the solid dielectric plate, and the engagement portion is opposite to the object side of the solid dielectric plate. Since the width dimension of the discharge space formed between the solid dielectric plates is defined by engaging the end portion on the side, the interval between the solid dielectric plates, that is, the discharge space The width dimension of the discharge space can be set without using a member that defines the width dimension (so-called spacer). Therefore, for example, even if each electrode is formed long in the direction orthogonal to the process gas introduction direction, there is no need to provide an intermediate spacer that defines the interval between the solid dielectric plates in the longitudinal direction of the electrode. Good.

  In addition, each of the electrodes has a facing surface parallel to the other electrode, and the cross-sectional shape of the end portion on the object to be processed side is thin. For example, the base member is a conductor such as metal. When configured, the area of the surface facing the base member in the portion closest to the base member (electrode end) in each electrode is reduced, and the capacitive coupling between the electrode and the base member can be weakened. When a high frequency voltage is applied to the base member, it is possible to suppress the base member from generating heat. In addition, since the high frequency electromagnetic field generated on the side of the electrode is weakened, the influence of the high frequency electric field on the substrate to be processed can be prevented.

It is a perspective view which shows an example of the external appearance structure of the plasma surface treatment apparatus which concerns on this invention. It is sectional drawing which cut | disconnected the reactor of the plasma surface treatment apparatus along the conveyance direction X of a conveyor. It is explanatory drawing which shows the structure of the electrode main body of the plasma surface treatment apparatus, FIG.3 (a) is the front view which looked at the electrode main body from the opposite side to an electrode opposing surface, FIG.3 (b) is the bottom view. is there. It is explanatory drawing which shows the structure of the solid dielectric board of the plasma surface treatment apparatus, FIG. 4 (a) is the front view which looked at the solid dielectric board from the electrode main body side, FIG.4 (b) is FIG. It is sectional drawing along the VV line of a). It is the fragmentary sectional view which shows other embodiment of the reactor in the plasma surface treatment apparatus, and is sectional drawing which cut | disconnected the reactor along the conveyance direction X of a conveyor. It is a fragmentary sectional view which shows the modification of the structure of the front-end | tip part of the solid dielectric plate in the plasma surface treatment apparatus. It is sectional drawing which shows the structure of the reactor in the conventional plasma surface treatment apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1

FIG. 1 shows an example of a plasma surface treatment apparatus according to the present invention.
The illustrated plasma surface treatment apparatus 1 is a discharge plasma (plasma activated treatment) obtained by applying a high-frequency electric field while introducing a treatment gas between a voltage application electrode and a ground electrode under a pressure near atmospheric pressure. Gas) is a device for conducting a surface treatment of the object to be processed W by introducing it into the object to be processed W arranged outside the discharge space, and as shown in FIG. 1, the object to be processed (substrate to be processed in the illustrated example) It is arrange | positioned on the conveyance path | route of the conveyor 2 which mounts and conveys W.

  Specifically, the plasma surface treatment apparatus 1 has a structure in which a reactor 4 (see FIG. 2) to which high-frequency power is supplied is accommodated in an elongated box-shaped apparatus cover 3 having an open bottom. And placed on an apparatus base (not shown) provided on the transport path across the transport path of the conveyor 2 (perpendicular to the transport direction X). The device cover 3 is composed of an electrically grounded conductor plate (for example, a metal plate such as stainless steel), and a shield case that shields the high frequency electric field generated in the reactor 4 from leaking outside. Playing a role.

  FIG. 2 is an explanatory diagram showing a schematic configuration of the reactor 4 accommodated in the apparatus cover 3, and shows a cross section of the reactor 4 cut along the conveying direction X of the conveyor 2.

  This reactor 4 is a device for activating a processing gas by dielectric barrier discharge, and as shown in FIG. 2, a pair of electrodes 5 arranged to face each other along the transport direction X of the object W to be processed. , 5 and a gas introduction block 6 for supplying a processing gas to the discharge space A formed between the electrodes 5 and 5 as main parts, and a base member 7 on which these main parts serve as a base, It accommodates in the housing | casing comprised by the some frame board member 8, 8, ... which forms the wall surface and ceiling surface of front and rear, right and left. More specifically, the electrodes 5 and 5 and the gas introduction block 6 are attached to the base member 7 and the frame plate member 8 via the electrode support stay 9.

  Here, the base member 7 is composed of a plate member made of metal such as aluminum having a substantially rectangular shape, and the base member 7 includes the frame plate members 8, 8,. , 9 are formed, and an opening 7b is formed as an outlet for blowing discharge plasma to the workpiece W conveyed by the conveyor 2. The opening 7b is formed in an elongated slit shape extending in a direction crossing the transport path of the conveyor 2 when the base member 7 is placed on the apparatus base.

  The electrode support stay 9 is a flat plate member used to support the electrode 5 and the gas introduction block 6, and the electrode 5 and the gas introduction block 6 are assembled to the electrode support stay 9. It is attached to the housing (details will be described later).

  One of the pair of electrodes 5 and 5 is a voltage application electrode 5a that is connected to a high frequency power source (not shown) and applied with high frequency power, and the other is a ground electrode 5b that is electrically grounded. As shown in FIG. 2, the voltage application electrode 5 a and the ground electrode 5 b have a symmetrical structure with the discharge space A in between, and both of them are solid bodies that cover the electrode body 51 and the electrode facing surface of the electrode body 51. The dielectric plate 52 and a dielectric filling layer 53 disposed around the electrode body 51 are configured.

  The electrode body 51 is an electrode made of a metal such as aluminum, and has an opposing surface (electrode opposing surface) 51a parallel to the other electrode as shown in FIG. 2, and at least an end on the object side. The cross-sectional shape of the part is formed to be thin. Specifically, as shown in FIGS. 2 and 3, the electrode main body 51 has an electrode facing surface 51 a having an elongated rectangular shape, and a cross-sectional shape (a cross-section along the conveyance direction X of the workpiece W). Is formed of a long electrode having a substantially trapezoidal shape. That is, in the present embodiment, not only the end portion on the object to be processed side but also the tapered surfaces 51b and 51b on the side opposite to the electrode facing surface 51a so that the entire peripheral portion of the electrode main body 51 is thinner than the central portion. , ... are formed.

  Here, the peripheral part of the electrode body 51 is thinner than the center part because the conductor parts (for example, the base member 7 and the electrode body 51 are disposed at both ends in the longitudinal direction of the electrode body 51). The area of the surface of the electrode body 51 closest to these conductor parts (electrode end part) with respect to the frame plate member 8) is reduced, and the capacitive coupling between these conductor parts and the electrode body 51 is weakened. This is for suppressing heat generation of the conductor parts. Moreover, it is because the high frequency electromagnetic field produced in the side of an electrode can also be weakened by making the peripheral part of the electrode main body 51 thin.

  The length of the electrode body 51 in the longitudinal direction (the front-rear direction in FIG. 2) depends on the width dimension (length in the direction orthogonal to the transport direction X) L of the conveyor 2 that transports the workpiece W. Is set. More specifically, the length of the electrode body 51 in the longitudinal direction is set to be longer than at least the width dimension of the workpiece W. That is, the length of the electrode main body 51 is set so that a portion where the plasma-activated processing gas does not act on the workpiece W conveyed by the conveyor 2 does not occur.

  Further, a cavity 54 for circulating the coolant over substantially the entire length in the longitudinal direction is formed inside the electrode body 51, and a coolant for introducing and discharging the coolant at both ends of the cavity 54. A pipe 55 is provided. Then, an insulating liquid such as pure water that is a coolant is circulated and pumped through the coolant pipe 55 to suppress heat generation of the electrodes 5 and 5. Note that this cooling is performed, for example, by keeping the electrode body 51 at 100 ° C. or less so that the workpiece W is not thermally damaged.

  The solid dielectric plate 52 functions as a dielectric layer for performing dielectric barrier discharge between the electrodes 5 and 5 and is plasma activated in the discharge space A together with the solid dielectric plate 52 of the other electrode 5. It serves as a guide passage for guiding the processed gas toward the workpiece W.

  Specifically, in the present embodiment, the solid dielectric plate 52 is obtained by cutting a plate-like alumina sintered plate (ceramic plate) integrally formed by sintering alumina into a desired shape. Yes. More specifically, as shown in FIG. 4, with respect to the alumina sintered plate having a rectangular shape with a thickness of about several millimeters (for example, thickness 5 mm), the surface facing the electrode body 51 is to be processed. The upper end portion 52a, which is the end portion on the opposite side, is not cut and the remaining portion 52b is cut thinly (for example, about 2.5 mm) while leaving the thickness, and the other surface (another solid dielectric) With respect to the surface facing the plate 52, cutting is performed so that a notch 56 is formed at the upper end of the plate 52, so that a ridge is formed at the upper end 52 a of the solid dielectric plate 52. . As described above, the solid dielectric plate 52 shown in this embodiment has a very simple shape, and there are few parts to be cut from the alumina sintered plate, and the cutting amount is very small. The solid dielectric plate 52 can be manufactured at low cost and at low cost.

  The length of the solid dielectric plate 52 in the longitudinal direction is set to be longer than that of the electrode body 51 so that at least the electrode facing surface 51a of the electrode body 51 can be covered over the entire length thereof. The length of the direction (processing gas introduction direction, vertical direction in FIG. 2) is the tip of the solid dielectric 52 on the object side in a state where the upper end 52a is engaged with the gas introduction block 6, as will be described later. The portion is set so as to reach the opening 7 a of the base member 7. More specifically, in the present embodiment, as shown in FIG. 2, the front end portion of the solid dielectric plate 52 on the target object side is set to be substantially flush with the surface of the base member 7 on the target object side. ing.

  The dielectric filling layer 53 serves as a dielectric covering the periphery of the electrode body 51 and serves to bond the electrode body 51 to the solid dielectric plate 52 and the electrode support stay 9. 2, in a space formed by the gas introduction block 6, the solid dielectric plate 52, and the electrode support stay 9 so as to cover the periphery of the electrode body 51, a liquid or gel-like dielectric (for example, (Silicon rubber, polyimide, etc.) are filled and solidified. A specific method for forming the dielectric filling layer 53 will be described in detail after the gas introduction block 6 is described.

  The gas introduction block 6 is a member provided to uniformly introduce a reaction gas (processing gas) supplied from a gas cylinder (not shown) into the discharge space A, and includes an upper block 61 and a pair of lower blocks 62a and 62b. And disposed above the solid dielectric plate 52 (on the end opposite to the object to be processed).

  Each of these blocks 61 and 62 is made of an insulating resin molded product, and the length in the longitudinal direction is set according to the solid dielectric plate 52.

  The upper block 61 includes a gas passage 64 having a substantially circular cross section penetrating in the longitudinal direction, and a gas diffusion space 65 having a substantially rectangular cross section provided below the gas passage 64 and penetrating in the longitudinal direction similarly to the gas passage 64. These are communicated by communication holes 66 provided at regular intervals.

  A gas diffusion plate (not shown) is disposed in the gas diffusion space 65 so as to face the communication hole 66, and the processing gas supplied from both ends of the gas passage 64 is gas through the communication hole 66. When introduced into the diffusion space 65, the gas diffuser strikes the gas diffusion plate and diffuses into the gas diffusion space 65. A sealing member (for example, an O-ring) 67 is disposed on the outer periphery of the gas diffusion space 64 so that the processing gas does not leak from the joint between the upper block 61 and the lower block 62.

  On the other hand, as shown in FIG. 2, the lower blocks 62a and 62b have a gas introduction path B for introducing the processing gas into the discharge space A at the joint between the opposing surfaces by abutting the opposing surfaces. It is comprised so that it may be formed. Specifically, in one or both of these lower blocks 62a and 62b, a concave groove that forms a gas introduction path B along the introduction direction of the processing gas is formed on the surface that forms the facing surface. A space having a rectangular cross section (gas introduction path B) penetrating along the introduction direction of the processing gas is formed between the concave grooves or the concave groove and the opposing surface of the other lower block by abutting the opposing surfaces. The

  The gas introduction path B can be formed in one space by forming a concave groove with a width close to the substantially entire length of the lower block 62 in the longitudinal direction. When the dimensions are long, a plurality of concave grooves are formed on the opposing surfaces of the lower blocks 62a and 62b, and a plurality of spaces serving as gas introduction paths B are formed in the lower block 62. Also good.

  Further, an engaging portion 63 that engages with the upper end portion 52a of the solid dielectric plate 52 is formed at the lower portion of the opposing surface of the lower blocks 62a and 62b. The engaging portion 63 is fitted with the upper end portion 52a of the solid dielectric 52 (specifically, the ridge formed on the upper end portion 52a) over the entire length in the longitudinal direction of each of the lower blocks 62a and 62b. A concave engaging groove that can be joined is formed downward, and the protruding portion of the upper end portion 52a of the solid dielectric plate 52 is fitted into the engaging portion 63, whereby the solid dielectric plate 52 The upper end portion 52a is positioned and fixed.

  Therefore, in the reactor 4 shown in the present embodiment, the opposed surfaces of the lower blocks 62a and 62b are abutted and fixed with the upper end portion 52a of the solid dielectric plate 52 engaged with the engaging portion 63 of the lower block 62. By doing so, the interval between the solid dielectric plates 52, in other words, the width dimension of the discharge space A is set. That is, the width dimension of the discharge space A is defined by the shape of the opposing surfaces of the lower blocks 62 a and 62 b and the shape of the upper end portion 52 a of the solid dielectric plate 52. The width dimension of the discharge space A is set to several millimeters (for example, about 0.5 to 2 mm).

  Next, a procedure for forming the dielectric filling layer 53 and a procedure for attaching the electrode 5 including the dielectric filling layer 53 to the housing will be described.

  In the reactor 4 shown in this embodiment, when forming the dielectric filling layer 53, first, parts other than the dielectric filling layer 53 are assembled first.

  That is, for the gas introduction block 6, the opposing surfaces of the lower flocks 62a and 62b are abutted with each other, and the lower blocks 62a and 62b are fixed to the electrode support stays 9 and 9 with bolts (not shown). The upper block 61 is fixed to each of the lower blocks 62a and 62b with bolts (not shown) while the O-ring 67 is interposed.

  On the other hand, for the electrodes 5 and 5, the upper end portions 52a of the solid dielectric plate 52 provided on the electrodes 5 are engaged with the engaging portions 53 of the lower blocks 62a and 62b, respectively. At that time, a seal member (for example, an O-ring) 68 that seals between the engaging portions 53 of the lower blocks 62a and 62b and the upper end portions 52a of the solid dielectric plate 52 is interposed. And about the space (space used as the discharge space A) formed between the solid dielectric plates 52 and 52, the sealing member (not shown) which seals this space is interposed in the both ends of the longitudinal direction. Then, the processing gas is prevented from leaking from both ends in the longitudinal direction.

  Further, the electrode body 51 has the electrode facing surface 51a facing the solid dielectric plate 52 so as to be in contact with it, and the cooling pipe 55 is inserted into the through hole 91 of the electrode support stay 9 disposed on the opposite side of the electrode facing surface 51a. Insert. A seal member (for example, an O-ring) 92 is disposed around the through hole 91 to maintain airtightness between the through hole 91 and the cooling pipe 55. Reference numeral 93 denotes a pressing member for the seal member 92.

  Here, with respect to the electrode support stays 9 and 9, in this embodiment, the electrode support stay 9a used on the voltage application electrode 5a side is made of an insulating material (for example, so as to prevent arc discharge from the voltage application electrode 5a). A stay made of glass epoxy obtained by hardening glass fiber with an epoxy resin is used, and a metal stay is used for the electrode support stay 9b on the side of the ground electrode 5b that does not cause arc discharge. An insulating stay may also be used for the electrode support stay 9b on the ground electrode 5b side.

  When the assembly of the parts other than the dielectric filling layer 53 is completed in this way, the gas introduction block 6 is set so as to be down (upside down from FIG. 2), and in this state, around the electrode body 51, that is, The back of the electrode body 51 is filled with a liquid or gel dielectric and solidified. This filling is performed until at least the upper end portion (lower end portion in FIG. 2) of the electrode body 51 is covered with the dielectric. In the present embodiment, the upper end portion of the electrode body 51 is filled so as to be covered with a dielectric having a thickness of about 1 millimeter. That is, in the present embodiment, the dielectric covering the upper end portion of the electrode body 51 is not so thick.

  Here, in consideration of the possibility of arc discharge from the electrode body 51 to the base member 7, it is preferable to thicken the dielectric covering the upper end portion (lower end portion in FIG. 2) of the electrode body 51. Or the usage-amount of a gel-like dielectric material increases. In particular, if the length of the electrode body 51 in the longitudinal direction is increased, the amount of dielectric required is increased accordingly, so that the upper end portion of the electrode body 51 is covered with a dielectric material thickly. This will increase costs.

  Therefore, in this embodiment, the dielectric covering this portion is thinned to suppress the amount of liquid or gel-like dielectric used as much as possible, thereby reducing the manufacturing cost. As an alternative to thinning the dielectric covering the upper end portion of the electrode body 51, a distance from the upper end portion (lower end portion in FIG. 2) of the electrode body 51 to the base member 7 is taken, and a space (that is, , An air layer), and the air layer prevents arc discharge from the electrode body 51 to the base member 7. In addition, the distance from the upper end part (lower end part in FIG. 2) of the electrode body 51 to the base member 7 is appropriately set so that arc discharge does not occur according to the magnitude of power applied to the electrode 5 (voltage application electrode 5a). Set.

  Thus, the electrodes 5 and 5 on which the dielectric filling layer 53 is formed in this way are attached to the base member 7 and the frame plate member 8 after the dielectric filling layer 53 is solidified. Specifically, the distal end portion of the solid dielectric plate 52 on the object to be processed side is inserted into the opening 7a of the base member 7, and in this state, the electrode support stays 9 and 9 are connected to the housing such as the base member 7 and the frame plate member 8. Secure to the body with screws. At this time, as described above, the front end portion of the solid dielectric 52 on the side of the object to be processed is substantially flush with the surface of the base member 7 on the side of the object to be processed, and the solid dielectric disposed in the opening 7 a of the base member 7. A space between the plates 52 and 52 serves as an outlet for the processing gas activated in the discharge space A by plasma.

  As described above, the reactor 4 according to the present embodiment is filled and solidified with a liquid or gel-like dielectric in a state where the electrode main body 51 is assembled to the solid dielectric plate 52 and the electrode support stay 9. 51 is adhered and fixed to the solid dielectric plate 52 and the electrode support stay 9 by the dielectric filling layer 53, and the position of the electrode body 51 is not shifted after being attached to the housing.

  In addition, since a liquid or gel-like dielectric permeates between the solid dielectric plate 52 and the electrode facing surface 52 of the electrode body 51, an air layer causing corona discharge is not formed between them, and the corona It is possible to provide an electrode structure in which the solid dielectric plate 52 is not deteriorated by discharge.

  In addition, since the periphery of the electrode body 51 is completely covered with the solid dielectric plate 52 and the dielectric filling layer 53, an electrode structure in which abnormal discharge (such as arc discharge or creeping discharge) from the electrode body 51 does not occur. Become.

Embodiment 2
Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 5 shows a modification of the reactor 4 of the first embodiment described above. The reactor 4 ′ shown in FIG. 5 is obtained by modifying the structure of the electrode body 51, and the other parts are the same as those in the first embodiment. Therefore, parts having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  In the reactor 4 ′ shown in FIG. 5, the electrode body 51 ′ is configured such that the cross section (cross section along the transport direction X of the workpiece W) has a substantially rectangular shape, A flange-shaped thin portion 51c is formed. That is, the electrode body 51 'is formed such that the peripheral edge of the electrode body 51' is thin by forming a flange-like thin part 51c instead of the tapered surface 51b in the first embodiment.

  Thus, by forming the flange-shaped thin part 51c instead of the tapered surface 51b, the cost required for manufacturing the electrode body 51 ′ can be suppressed. That is, although an electrode made of aluminum can be suitably used as the electrode main body 51, the cost of cutting increases to form the tapered surface, but in this embodiment, a simpler shape is adopted. Thus, the cost required for the cutting of the electrode main body 51 'can be suppressed at a low cost, and as a result, the plasma surface treatment apparatus 1 can be provided at a lower cost.

  Note that the above-described embodiments merely show preferred embodiments of the present invention, and the present invention is not limited to these, and various design changes can be made within the scope thereof.

  For example, in the above-described embodiment, the solid dielectric plate 52 has a configuration in which the tip portion on the processing object side is merely inserted into the opening 7a of the base member 7, that is, a configuration in which the tip portion of the solid dielectric plate 52 is not fixed. As shown in FIG. 6, a notch is formed in a portion facing the other solid dielectric plate 52 at the front end portion of the solid dielectric plate 52, and this notched portion is attached to the ba member 7. It may be configured to prevent the tip of the solid dielectric plate 52 from being distorted toward the other solid dielectric plate 52 by being pressed by the holding member 71 to be pressed. The pressing member 71 is fixed to the base member 7 with screws through a screw hole 7 c provided in the base member 7.

  In the above-described embodiment, the case where the engaging portion 63 for positioning the solid dielectric plate 52 is provided in the gas introduction block 6 is shown. However, the solid dielectric plate 52 is positioned on the solid dielectric plate 52. What is necessary is just to perform between the members arrange | positioned adjacently, positioning between members other than the gas introduction block 6, and the width dimension of the discharge space formed between solid dielectric plates by this is carried out. You may comprise so that it may prescribe | regulate.

  In the above-described embodiment, the engagement between the gas introduction block 6 and the solid dielectric plate 52 is caused by the upper end of the solid dielectric 52 in the concave engagement groove (engagement portion 63) formed on the gas introduction block 6 side. Although the case where it is performed by fitting the portion 52a is shown, the engagement of the gas introduction block 6 and the solid dielectric plate 52 may be performed by a method other than the fitting.

In the above-described embodiment, a case where a ceramic plate is processed and used as the solid dielectric plate 52 has been described. However, the material of the solid dielectric plate 52 is not limited to ceramics, but other solid dielectric such as glass. It is also possible to use the body.

  Further, in the above-described embodiment, the case where the object to be processed that is the target of the plasma surface treatment is the substrate to be processed, but the target of the surface treatment in the plasma surface treatment apparatus of the present invention is not limited to the substrate. For example, various materials such as films and fabrics can be used for surface treatment.

DESCRIPTION OF SYMBOLS 1 Plasma surface treatment apparatus 2 Conveyor 3 Apparatus cover 4 Reactor 5 Electrode 51 Electrode main body 52 Solid dielectric board 53 Dielectric filling layer 6 Gas introduction block 61 Upper block 62 Lower block 63 Engagement part 64 Gas passage 65 Gas diffusion space 7 Base Member 9 Electrode support stay A Discharge space B Gas introduction path W Object to be treated

Claims (7)

In the electrode structure in which each electrode facing surface of a pair of electrodes arranged so as to form a discharge space is covered with a dielectric,
In this state, a substantially plate-shaped solid dielectric plate is disposed facing the electrode facing surface of each electrode, and an electrode support stay for supporting each electrode is disposed on the opposite side of the electrode facing surface of each electrode. Then, each electrode is adhered to a solid dielectric plate disposed on each side and an electrode support stay by filling the electrode with a liquid or gel dielectric around the electrode and solidifying the electrode. An electrode structure characterized in that the periphery of the substrate is covered with the solid dielectric plate and the solidified dielectric.   2. The electrode structure according to claim 1, wherein an electrode support stay disposed on at least an electrode side to which a voltage is applied is made of an insulating material.   The width of the discharge space formed between the solid dielectric plates by engaging at least one side of the peripheral portion of the solid dielectric plates with a member disposed adjacent to the solid dielectric plate. 3. The electrode structure according to claim 1, wherein dimensions are defined. A discharge plasma obtained by applying a high-frequency electric field while introducing a processing gas into a discharge space formed between a pair of electrodes arranged opposite to each other is guided to an object to be processed disposed outside the discharge space. A plasma surface treatment apparatus for performing body surface treatment, wherein the pair of electrodes includes the electrode structure according to any one of claims 1 to 3,
The electrode support stay is fixed to a base member disposed so as to face the object to be processed, and a tip portion of each solid dielectric plate is formed in an opening for discharging discharge plasma formed in the base member. A plasma surface treatment apparatus characterized by being fitted. A pair of gases forming a gas introduction path for introducing the processing gas into the discharge space at the junction by abutting the opposing surface at the end of each solid dielectric plate opposite to the object to be processed An introduction block is arranged,
An engagement portion that engages with the solid dielectric plate is formed in each of the gas introduction blocks, and an end of the solid dielectric plate opposite to the object to be processed is engaged with the engagement portion. The plasma surface treatment apparatus according to claim 4, wherein a width dimension of the discharge space formed between the solid dielectric plates is defined.   6. The solid dielectric plate according to claim 4, wherein each solid dielectric plate is set so that an end surface of a distal end portion on the processing object side is substantially flush with a surface of the base member on the processing object side. Plasma surface treatment equipment.   7. The pair of electrodes according to claim 4, wherein each of the pair of electrodes has a facing surface parallel to the other electrode, and the cross-sectional shape of the end portion on the object side is thin. The plasma surface treatment apparatus according to 1.

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