JP4486385B2 - Seal plate for valve device - Google Patents

Description

  The present invention relates to a seal plate for a valve device, and more particularly to a seal plate that is disposed on a valve body of a valve device such as a gate valve and that opens and closes a valve seat surface surrounding the opening. ing.

The gate valve is used in a semiconductor processing apparatus, a thin film forming processing apparatus, and the like. It is used to open and close an opening through which processing materials are taken in and out of a processing chamber that requires a high vacuum state or a high airtight state.
The basic operation of the gate valve, the valve seat surface provided to surround the opening to open and close, the disk-shaped seal plate having a movably valve body, by contact and separation operation the valve seat surface The opening is closed and opened . A sealing ring made of an elastic seal material such as an O-ring provided on the seal plate where it comes in contact with and away from the valve seat surface is pressed against the valve seat surface, so that the opening of the valve seat surface is made airtight. Seal.

In Patent Document 1, instead of an O-ring having a circular cross section, a substantially heart-shaped sealing ring with the lower end side expanded to the left and right as compared to the tip is used, and a trapezoid with a narrow opening and a deeper back is used for the seal plate. A technique for providing a sealing ring mounting groove having a cross section, that is, a dovetail shape is shown. By inserting a specially shaped sealing ring into the dovetail mounting groove while elastically deforming, the mounting operation is relatively easy, and after mounting, the sealing ring does not easily come out of the mounting groove. It is said that there is.
The sealing ring shown in Patent Document 2 has a cross-sectional shape that protrudes in a parabolic shape at the center, extends outward at the left and right roots, and further curves upward. A rubber sealing ring inserted into the concave mounting groove of the plate body is integrally bonded to the plate body by vulcanization. In this technique, since the sealing ring is bonded to the plate body, it does not fall off.
JP 10-318373 A Special table 2001-512897 gazette

Among the seal plates used in the conventional gate valve, as in Patent Document 1, the structure in which the sealing ring is inserted into the mounting groove such as the dovetail groove repeatedly opens and closes the seal plate. In the meantime, the sealing ring may roll or shift in the mounting groove, and a sufficient sealing function may not be exhibited.
Further, in a gate valve that is exposed to a plasma atmosphere or a high temperature, a sealing ring made of rubber or the like increases the adhesiveness of the material and is easily fixed to the valve seat surface. Even if the seal plate is to be opened, the sealing ring remains fixed to the valve seat surface side and may come out of the mounting groove. Even if a structure such as the above-mentioned dovetail that is difficult to be removed is employed, the sealing ring that is firmly fixed to the valve seat surface may come out.

As in Patent Document 2, if the sealing ring is bonded to the seal plate, the sealing ring falls off the seal plate as long as the sealing ring is bonded with a force stronger than the fixing force to the valve seat surface. Never do.
However, in the case of this structure, when the lifetime of the sealing ring has passed and the sealing ring has to be replaced, not only the sealing ring but also the entire sealing plate must be replaced. When the material of the sealing ring is likely to deteriorate and it is necessary to replace the sealing ring in a relatively short period of time, such as a gate valve of a plasma processing apparatus, the sealing plate and the entire seal plate It takes time and effort to change frequently. Since the seal plate incorporates a mechanism for performing an opening / closing operation and a structure for mounting to the gate valve, the manufacturing cost is considerably increased. Replacing the entire costly seal plate is uneconomical and increases the operating cost of the device fitted with the gate valve.

The used seal plate after replacement can be reused by separating the metal portion which is the main body of the seal plate and the sealing ring portion such as rubber. However, the work of peeling or scraping off the strongly bonded sealing ring from the plate body is very laborious and costly. The merit of reusing the plate body is scarce. It is also troublesome to separate the metal part and the rubber part for disposal.
The problem of the present invention is that, as a seal plate used in a valve device such as the gate valve described above, the sealing member is difficult to roll, shift or slip out, and the replacement or disposal of the sealing member is easy. It is to be able to exhibit high sealing performance without increasing the usage cost.

Seal plate for such a valve device of the present invention is arranged in the valve body of the valve device, a seal plate for opening and closing operation apart against the valve seat surface facing the valve body, the opening of the valve seat surface A plate-like plate body facing each other; a sealing member disposed on a front surface of the plate body opposite to the valve seat surface; and having an annular elastic sealing portion contacting and separating from the valve seat surface; and the elastic sealing portion includes but inside the position approaching and moving away from said valve seat surface, and a clipping plate across the portion is detachably fixed to the front surface of the plate body of the sealing member between the plate body The clamping plate has a female screw hole provided from the surface facing the plate main body to the middle of the thickness direction, and the plate main body is located at a position corresponding to the female screw hole of the clamping plate. A screw insertion hole penetrating through the back of the plate body The screwed into the female screw hole through the screw insertion holes, Ru provided with a mounting screw to secure the clamping plate to the plate body from.
(Valve device)
It can be applied to various valve devices using a seal plate.

Specific examples of the valve device include a gate valve.
The valve device includes a valve seat surface that exists around the opening to be opened and closed, and a valve body that performs an opening and closing operation that closes the opening by contacting the valve seat surface and releases the opening away from the valve seat surface. Prepare. For the material and structure of the valve seat surface and valve body other than the seal plate, basically, a technique common to a normal valve device or a gate valve can be adopted.
The valve body opening / closing operation moves linearly with respect to the valve seat surface from the normal direction and makes contact / separation from an oblique direction, or makes contact / separation with turning, combining these movements There are also things.

The valve device can include a drive mechanism that drives the valve body. As the drive mechanism, an electromagnetic drive mechanism or the like can be employed in addition to a mechanical drive mechanism.
<Gate valve>
A gate valve provided with a seal plate is used in an opening portion serving as an entrance / exit of a semiconductor substrate or the like to be processed in a processing chamber such as a semiconductor manufacturing apparatus, a plasma processing apparatus, a thin film forming apparatus, or a dry etching apparatus. Such a gate valve is configured as an independent part, and may be used by being incorporated in a device for mounting a completed gate valve. You may be comprised integrally with the structural member of the apparatus with which a gate valve is attached. For example, the valve seat surface can be a part of a wall material provided with an opening in a processing chamber of a semiconductor manufacturing apparatus.

[Seal plate]
The valve body of the valve device may be the seal plate itself, or the seal plate may constitute a part of the valve body. For example, the valve plate can be configured by incorporating a seal plate into a structural member of the valve body or adding a drive mechanism, drive control mechanism, safety mechanism, attachment mechanism, or the like of the valve body.
The basic structure of the seal plate is a board or plate having a plate body and a sealing member.
[Plate body]
The valve seat surface around the opening of the valve device is closed to form a disk shape.

A material having structural strength and durability that can withstand the pressure, temperature, and gas atmosphere applied to the opening is used. For example, a metal such as stainless steel or aluminum or a metal alloy is used depending on the use environment. Ceramic or synthetic resin may be used. A protective coating film may be provided on the surface that may come into contact with plasma or corrosive gas in use.
The overall shape of the plate body is set in accordance with the shapes of the opening and the valve seat surface. The valve seat surface can be closed with a sufficient width one size larger than the opening. As a specific shape, a rectangular shape can be adopted in a general gate valve. Depending on the structure of the valve device, there is a curved shape such as a polygon other than a rectangle, a circle, and an oval. Although the magnitude | size of a plate main body changes with structures of a valve apparatus, it is the range of 20-40 cm by the length of a largest side normally.

The plate body has an attachment structure for the sandwiching plate and the sealing member on the front surface facing the valve seat surface when in use. Further, similarly to a normal seal plate, a structure for connecting to a drive mechanism, an attachment mechanism, a control mechanism, etc. of the valve body can be provided.
As an attachment structure of the sandwiching plate, an accommodation recess into which the sandwiching plate is inserted can be provided. A screw insertion hole for a mounting screw for fixing the sandwich plate can be provided.
(Sealing member)
It arrange | positions in the front surface which opposes a valve seat surface among plate bodies. An annular elastic sealing portion that contacts and separates from the valve seat surface is provided.

The sealing member may be composed of only the elastic sealing portion, and in addition to the elastic sealing portion, a structure for attaching the sealing member to the plate body, a structure for supporting the elastic sealing portion, and the like. It can also be prepared.
For example, what has a support plate inserted | pinched between a plate main body and a clamping board and the elastic sealing part arrange | positioned along the outer periphery of a support plate is employable.
(Elastic sealing part)
The whole or part of the sealing member is configured.
An airtight seal between the seal plate and the valve seat surface is achieved by contacting and separating from the valve seat surface. A circumferential ring is formed so that the entire circumference can be contacted along the valve seat surface around the opening.

In a normal seal plate, a technique called an elastic seal material or a seal ring can be used.
<Materials and manufacturing>
As a material for the elastic sealing portion, a material common to a normal elastic sealing material or the like can be used. For example, elastic rubber, elastic resin, elastic elastomer, etc. can be used.
Specifically, fluorine rubber having excellent heat resistance and plasma resistance is suitable as a gate valve of a semiconductor manufacturing apparatus. As the fluorinated rubber, a crosslinkable fluororubber (sometimes abbreviated as “FKM”) having a carbon-hydrogen bond in a part of main chain carbon atoms can be used. Examples of the crosslinkable fluororubber include binary crosslinkable fluororubbers such as vinylidene fluoride / hexafluoropropylene, and ternary crosslinkable fluororubbers such as vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene. There are a trade name “Viton” (manufactured by DuPont) and a trade name “Daiel G902” (manufactured by Daikin Industries).

Perfluoro-crosslinkable fluororubbers (also called “FFKM”) in which hydrogen atoms bonded to main chain carbon atoms are completely fluorinated (100%) are superior in heat resistance and plasma resistance among fluororubbers. Excellent but costly. There is a trade name “Daiel Perflo G55” (manufactured by Daikin Industries) and a trade name “Kalrez” (manufactured by DuPont).
A fluorine-based thermoplastic elastomer can be used as the meltable fluorine-based rubber, and there is a trade name “Dai-L Thermoplastic” (manufactured by Daikin Industries).
In order to produce an elastic sealing part using a fluorine-based rubber such as FKM or FFKM, a compound obtained by mixing and kneading a rubber raw material with a crosslinking agent, a co-crosslinking agent, a filler, and other rubber molding additive materials is used. The mold can be filled and hot press molding can be performed. As molding conditions for hot press molding, for example, 170 ° C. and 20 minutes can be applied in the case of FKM, and 180 ° C. and 30 minutes can be applied in the case of FFKM.

In the case of a fluorinated thermoplastic elastomer, the elastic sealing portion can be produced not only by hot press molding but also by melt molding.
In either case, it can be adjusted to the intended physical properties by irradiation with radiation after molding.
<Shape and structure>
The shape of the elastic sealing portion is not particularly limited as long as contact with / separation from the valve seat surface and airtight sealing are satisfactorily achieved, and a shape similar to that of a normal elastic sealing material can also be adopted. For example, the cross-sectional shape may be a circular shape such as an O-ring, a rectangular shape, a trapezoidal shape, an elliptical shape, or the like. Some have a more complicated shape, such as a portion with irregularities.

If the cross-sectional shape is wider on the plate body side than on the side that is in contact with and away from the valve seat surface, it can be reliably supported by the mounting groove composed of the plate body and the sandwiching plate. Even if the sealing member is composed of an elastic sealing portion that does not have a support plate, it is unlikely to come out of the mounting groove or roll.
[Support plate]
The elastic sealing portion is supported, and is sandwiched and fixed between the plate body and the sandwiching plate, thereby fulfilling a function of supporting the elastic sealing portion on the seal plate. It also functions to prevent the elastic sealing portion from floating, deforming, or changing its posture.
The material of the support plate needs to have mechanical strength and rigidity capable of supporting the elastic sealing portion. Environmental resistance that can withstand the usage environment of the valve device is also required. For example, steel such as stainless steel or a steel alloy can be used. Metals such as iron, aluminum and copper or alloys thereof can also be used.

If the support plate is made of a metal gasket material, it is effective to attach the support plate tightly and airtight to the plate body and the sandwich plate. As a metal gasket material, the metal gasket material currently used for the normal sealing use can be used. For example, soft metal materials such as copper and aluminum materials used for vacuum gaskets can be used. If the plate body or the sandwich plate has a sealing protrusion, when the sandwich plate is fixed to the plate body, the sealing protrusion comes into contact with the support plate made of the metal gasket material, Concentration of pressure occurs at the contact point, airtightness is increased, and it functions well as an airtight seal.
Although the thickness of a support plate changes also with materials to be used, it can be normally set to 0.3-5 mm.

The support plate is integrally joined to a portion that can be reliably supported without adversely affecting the function of the elastic sealing portion, such as the lower surface of the elastic sealing portion, by means such as adhesion, heat fusion, vulcanization adhesion, and fitting. When the elastic sealing portion is molded, a support plate can be placed on the mold and can be integrally joined to the support plate simultaneously with the formation of the elastic sealing portion.
The support plate can be configured in a circumferential frame shape corresponding to the circumferential annular elastic sealing portion. The support plate has a portion that protrudes or projects from the elastic sealing portion so that the support plate can be sandwiched between the plate body and the sandwich plate. Usually, a part of the support plate disposed on the lower surface of the elastic sealing portion is protruded inward from the elastic sealing portion, and the protruding portion is sandwiched between the plate body and the sandwiching plate. The support plate may be present in the entire region inside the elastic sealing portion. An annular elastic sealing portion can be provided along the outer periphery of the plate-like support plate.

<Elastic covering part>
Covering both sides of the support plate, it is formed integrally with the elastic sealing portion.
It is comprised with the same material as an elastic sealing part. The thickness of the elastic covering portion only needs to exhibit the intended function, and varies depending on the material used, but can usually be set in the range of 0.5 to 5 mm.
The support plate, the plate body sandwiching the support plate, and the sandwiching plate are brought into close contact with each other, and the mounting function is performed in an airtight state.
Since the elastic cover part integrated with the elastic sealing part is integrated with the support plate in a wide area, the elastic sealing part may be lifted or peeled off from the support plate due to fixation with the valve seat surface. Can be prevented. As a result, a stable sealing function can be exhibited even when used for a gate valve or the like that frequently repeats opening and closing operations.

When fixing the clamping plate to the plate body with mounting screws, the elastic cover of the support plate sandwiched between them is elastically deformed, preventing loosening of the mounting screws and preventing a decrease in tightening pressure Can also be demonstrated.
The production of the support plate having the elastic covering portion may be performed by pasting the pre-manufactured sheet-like elastic covering portion to the support plate, but when the elastic covering portion and the elastic sealing portion are integrally formed, If the molding is performed in a state where the support plate is disposed on the substrate, it can be integrated with the support plate simultaneously with the molding. If an elastic elastomer or the like is integrally heated and pressed around the surface of the support plate with an adhesive applied, the integrity of the support plate, the elastic covering portion, and the elastic sealing portion is improved. As an adhesive used at this time, a trade name “Metaloc S-10A” (manufactured by Toyo Chemical Laboratory Co., Ltd.) can be used.

The elastic covering portion may be provided on the entire surface of both sides of the support plate, or may be provided only on a part of the support plate as long as the intended function can be achieved. For example, the support plate can be in a state where the support plate is exposed without providing the elastic cover portion on the entire circumference on the side close to the elastic sealing portion of the support plate and without providing the elastic cover portion on the center side. If a bridge-like or belt-like elastic covering portion that is intermittently traversed is provided on the center side where no elastic covering portion is basically provided, the integrity of the elastic covering portion with respect to the support plate is enhanced.
The thickness of the elastic covering portion can be relatively thick on the side close to the elastic sealing portion and thin on the center side of the support plate.
[Clamping plate]
Inside the position where the elastic sealing portion contacts and separates from the valve seat surface, the sealing member is sandwiched between the plate body and is detachably fixed to the front surface of the plate body. It fulfills the function of attaching the sealing member to the plate body. A part of the sealing member is covered to protect from a plasma atmosphere or the like.

The material of the sandwich plate can be selected from materials common to the plate body. The same material as the plate body may be used, or a different material may be selected. A protective coating film for the use environment can be provided on the surface of the sandwich plate that is exposed in use.
The structure of the sandwiching plate is set according to the structure of the elastic sealing portion of the sealing member and the support plate. When the sealing member is composed of only the elastic sealing portion, a part of the outer end of the sandwiching plate can constitute the mounting groove of the elastic sealing portion.
At this time, a part of the sandwiching plate constituting the mounting groove may be attached in a state of being in contact with the elastic sealing portion, or may be disposed through a gap that does not allow the elastic sealing portion to come out. Also good. Even when there is a gap between the elastic sealing portion, when the seal plate is pressed against the valve seat surface and hermetically sealed, the elastic sealing portion forms a mounting groove due to deformation of the elastic sealing portion. Abut.

When the sealing member is composed of an elastic sealing portion and a support plate, the support plate is sandwiched between the plate body and fixed by the sandwiching plate. The sandwiching plate does not have to be in contact with the elastic sealing portion. However, if the sandwiching plate is in contact with the elastic sealing portion at a part of the outer end of the sandwiching plate, the elastic sealing portion moves inward or deforms. Can be regulated.
The thickness of the sandwich plate is sufficient to ensure that the sealing member can be securely attached to the plate body, and that the position and orientation of the sealing member can be prevented and that the sealing member can be prevented from falling off the plate body. It can be set so that it can have an appropriate strength and rigidity. However, if the sandwiching plate is too thick, the entire thickness of the seal plate may increase or the thickness of the plate body must be relatively reduced. Usually, the thickness is set to 3 to 10 mm, although it varies depending on the material of the sandwich plate.

In addition to using only one sandwich plate for the plate body, a plurality of sandwich plates can be used in combination. For example, the sandwiching plates divided into the left and right can be arranged so as to cover the inner space of the elastic sealing portion, or the portion along the inner side of the elastic sealing portion and the central portion can be constituted by separate members. .
[Fixing the clamping plate]
If the sandwiching plate can be detachably fixed to the front surface of the plate main body, a detachable fixing means for members in a normal mechanical device can be employed. Specific examples include fittings and engagements, screw fittings such as bolts, and fastening fittings such as clamps, clips, and snaps.

In a state where the seal plate is used, it is possible to maintain high airtightness if a boundary or a gap between members is not exposed at a place where it comes into contact with plasma or corrosive gas or faces a vacuum atmosphere. Therefore, it is preferable that the attachment / detachment fixing means of the sandwiching plate is not exposed on the front surface of the sandwiching plate.
The sandwich plate has a female screw hole provided in the middle of the thickness direction from the back surface to the front surface facing the plate body, and the plate body has a plate body at a position corresponding to the female screw hole of the sandwich plate. If it has the screw insertion hole which penetrates, the clamping plate can be fixed to the plate body by screwing the mounting screw into the female screw hole of the clamping plate through the screw insertion hole from the back side of the plate body. In this structure, the female screw hole and the mounting screw are not exposed to the front side of the sandwiching plate.

[Receiving recess]
The sandwiching plate can be disposed in the housing recess provided on the front surface of the plate body.
The housing recess in which the plate-shaped sandwiching plate is arranged can employ a structure in which the bottom surface is flat and the inner surface rises around the bottom surface.
The depth of the housing recess can be set so that the front surface of the sandwiching plate housed in the housing recess is disposed on the same plane as the front surface of the plate body existing around the housing recess. If the airtight sealing function by the elastic sealing portion of the sealing member can be sufficiently exerted, the front surface of the sandwich plate disposed inside the elastic sealing portion, the front surface of the plate body existing outside the elastic sealing portion, However, they do not have to exist on the same plane.

The inner side surface of the housing recess can be a tapered inclined surface that narrows from the opening side to the bottom side. In this case, the outer surface of the sandwich plate is also a tapered inclined surface corresponding to the inner surface of the housing recess. Thus, the sandwiching plate can be easily accommodated in the accommodating recess. A gap is less likely to occur between the outer surface of the sandwich plate and the inner surface of the housing recess. The inner side surface of the housing recess may be inclined on the entire length from the opening to the bottom, or only a part such as the upper part or the lower part may be inclined.
Steps and irregularities that overlap each other can be provided on the inner surface of the housing recess and the outer surface of the sandwich plate. It is possible to appropriately determine the position and posture of each other with steps and unevenness, and to improve the airtightness between the two.

A mounting groove for mounting the sealing member can be formed between the inner peripheral end near the opening of the inner side surface of the housing recess and the outer peripheral end of the sandwiching plate facing it.
[Mounting groove]
A sealing member that is configured between the inner peripheral end of the accommodating recess and the outer peripheral end of the sandwich plate and basically configured only by the elastic sealing portion is accommodated.
The basic structure of the mounting groove is the same as that of a normal sealing ring. If the mounting groove has a cross-sectional shape that is wider on the inner side than the opening on the front surface, the accommodated sealing member can be prevented from slipping out. Specifically, a trapezoidal shape or a convex cross-sectional shape known as a dovetail can be employed.

The mounting groove formed by the receiving recess of the plate body and the sandwich plate reduces the clearance and margin between the outer shape of the sealing member compared to the conventional mounting groove formed on the front surface of the plate. I can leave. There may be virtually no gaps.
In the receiving recesses of the sandwich plate and the plate body, the surface constituting the inner surface of the mounting groove is subjected to surface finishing by buffing or chemical polishing, etc., so that the contact and adhesion with the elastic sealing portion are improved. it can. Effective for valve devices that require high vacuum. It is effective to apply the same surface finish to the surface constituting the O-ring groove constituting the hermetic sealing portion.
(Airtight seal)
Any one of the facing surface between the plate body and the sandwiching plate, the facing surface between the plate body and the support plate, and the facing surface between the sandwiching plate and the support plate is arranged in an annular shape inside the elastic sealing portion. . The inner peripheral side and the outer peripheral side of the hermetic sealing portion on each facing surface are hermetically cut off. Even a seal plate composed of a plurality of members such as a plate main body and a sandwich plate can satisfactorily hermetically seal the space inside the valve seat surface with respect to the space on the back side of the seal plate. .

A structure or means for hermetically sealing the opposing surfaces in a normal mechanical device can be employed. Specifically, sealing protrusions, O-rings, metal gaskets, and the like can be used.
<Sealing protrusion>
As the hermetic sealing portion, a sealing projection that is disposed on one of the opposing surfaces and protrudes toward the opposing side can be employed. Since the sealing projection comes into contact with the mating surface, the hermetic sealing function at the contact portion is enhanced.
Specifically, the sealing protrusions provided on the plate main body and the sandwiching plate can be brought into contact with both surfaces of the support plate of the sealing member sandwiched therebetween. It is also possible to provide sealing protrusions on both sides of the support plate and make contact with the plate body and the sandwich plate so as to bite. If the support plate has elastic covering portions on both sides, the sealing protrusions of the plate main body and the sandwiching plate are brought into contact with the elastic covering portions, and the elastic covering portions are elastically deformed to improve the airtightness. Can do. If the support plate is made of a metal gasket material, the sealing function by the contact of the sealing projections of the plate body and the sandwich plate can be satisfactorily exhibited.

The shape and dimensions of the sealing protrusion also vary depending on the material of the member on which the sealing protrusion is provided and the material of the opposing counterpart member. If the tip of the sealing projection is sharp and sharp, stress concentrates on the contact portion of the tip, and high airtightness can be exhibited even if the counterpart member is a hard material such as metal. If the mating member is rubber or resin, it is effective to prevent damage to the mating member by rounding the tip of the sealing projection. What is necessary is just to set the height of a sealing protrusion so that the target airtight sealing function can be fulfilled, and it can usually be set to 0.5-2 mm.
<O-ring>
As the hermetic sealing portion, an O-ring disposed on one of the opposing surfaces can be employed. The O-ring is mounted in the O-ring mounting groove and abuts against the opposing surface on the other side to achieve hermetic sealing. Various sealing rings other than O-rings and sealing means such as gaskets can also be employed.

[Air vent hole]
The plate main body can have an air vent hole penetrating from the surface facing the sandwich plate to the back surface.
When fixing the sandwich plate to the plate body, if the air pool remains between the plate body and the sandwich plate or the air is trapped, the integrity of the plate body and the sandwich plate may not be sufficient, The position and posture of the sandwich plate with respect to the plate body may be shifted.
In the case of a valve device that requires a highly airtight state, for example, a gate valve attached to an opening of a processing chamber of a semiconductor manufacturing apparatus, air remaining between the plate body and the sandwich plate and components contained in the air are contained in the processing chamber. When mixed, a strictly controlled atmosphere in the processing chamber is contaminated, and the quality performance of the processing operation is greatly deteriorated. When the processing chamber is depressurized to a predetermined vacuum state, it takes a long time for the depressurization operation.

If there is an air vent hole, the air between the plate body and the sandwich plate is discharged from the air vent hole to the back side of the plate body. When the valve device is used, the problem that air is mixed into the processing chamber or the like and the atmosphere is contaminated can be solved. If the hermetic sealing portion exists outside the air vent hole, there is no fear that air leaks from the air vent hole to the front side of the seal plate.
The air vent hole may be disposed at a position and shape that are effective for solving the above-described problems. Since air or the like may enter from the outside through the air vent hole, it is not necessary to provide an unnecessarily large air vent hole or an extra air vent hole.
For example, an air vent hole having an inner diameter of 1 to 3 mm can be provided. Although it differs depending on the width and shape of the opposing surfaces of the plate main body and the sandwiching plate, it is effective to arrange air vent holes at an interval of 10 to 150 mm on the opposing surfaces of the plate main body and the sandwiching plate.

The sealing plate for a valve device according to the present invention includes a sandwiching plate that is detachably fixed to the plate body with the sealing member interposed between the plate body and the sealing function of the sealing member. In addition, the sealing member can be attached and removed or replaced quickly and easily.
In particular, unlike the conventional case, it is not necessary to provide an extra space or an extra space for facilitating the insertion and removal of the sealing member in the mounting groove for mounting the sealing member, and the sealing function of the sealing member is improved. An appropriate structure and shape can be employed to achieve this. As a result, when the seal plate is opened, the sealing member sticks to the valve seat surface and comes out of the mounting groove of the seal plate, the sealing member rolls inside the mounting groove, or the posture changes. It can solve the problem of causing deformation or unexpected deformation. When the sealing member is mounted in the mounting groove, the sealing member is not excessively deformed and damaged.

  In order to replace the sealing member, it is not necessary to replace the entire seal plate, and there are only a few parts such as an elastic sealing part that performs a sealing function or only an elastic sealing part and a support plate that supports the sealing part. Therefore, the cost required for replacement is not high.

FIG. 1 shows a semiconductor manufacturing apparatus having a gate valve structure using a seal plate according to an embodiment of the present invention.
[Semiconductor manufacturing equipment]
In the semiconductor manufacturing apparatus 10, electrodes 16 and 18 are arranged vertically on the inside of a processing chamber 12 closed by an openable / closable closing lid 14. A voltage is applied to both electrodes 16 and 18 via wirings 17 and 19. The wall material of the processing chamber 12 is grounded by the wiring 11, and a voltage can be applied between the electrodes 16 and 18. A workpiece W such as a silicon substrate is disposed on the lower electrode 16. A desired plasma process can be performed on the workpiece W by the plasma generated in the processing chamber 12 by the action of the high-frequency voltage applied between the wirings 11, 17, and 19. Although not shown, the processing chamber 12 is also connected with a processing gas introduction path and a vacuum exhaust path.

In the side wall of the processing chamber 12, an opening 15 for taking in and out the workpiece W such as a silicon substrate is provided. The opening 15 usually has an elongated rectangular shape on the side. A passage 20 is connected to the outside of the opening 15. The workpiece W conveyed through the passage 20 is sent from the opening 15 to the processing chamber 12. The processed workpiece W is taken out from the opening 15 through the passage 20 or sent to the next processing step.
While performing various processing operations in the processing chamber 12, it is necessary to close the opening 15 and keep it airtight. It is necessary to prevent the plasma atmosphere, high vacuum state, high heat atmosphere, gas atmosphere, etc. generated in the processing chamber 12 from leaking from the opening 15 to the passage 20 side.

Therefore, the opening 15 is provided with a gate valve structure.
[Gate valve structure]
As shown in FIG. 1, the passage 20 connected to the processing chamber 12 is equipped with a seal plate 30 that closes the opening 15 of the processing chamber 12.
When the opening 15 has an elongated rectangular shape, the seal plate 30 has a similar rectangular shape that is slightly larger than the opening 15. As shown in the figure, the seal plate 30 performs a transition operation between a state in which the opening 15 is closed and a state in which the opening 15 is opened by turning to the side of the passage 20 from one side. An outer wall of the processing chamber 12 at the peripheral edge of the opening 15 serves as a valve seat surface, and the seal plate 30 serves as a valve body.

On the front surface of the seal plate 30, that is, the side facing the opening 15, a sealing member 50 made of an annular elastic sealing material is attached along the outer peripheral edge of the seal plate 30. When the sealing member 50 is pressed against the periphery of the opening 15, the opening 15 is hermetically sealed.
Although not shown, a drive mechanism for moving the seal plate 30, a mechanism for pressing the seal plate 30 toward the opening 15, a mechanism for fixing the seal plate 30 at an open position away from the opening 15, and the seal plate 30 A mechanism device similar to a normal gate valve, such as a sensor mechanism for detecting the open / closed state of the valve, is incorporated as necessary.
The opening 15 is hermetically sealed with the seal plate 30 while various kinds of processing are performed on the workpiece W inside the processing chamber 12, and the vacuum state in the processing chamber 12 is maintained, or the processing chamber 12 is processed. The gas atmosphere and the plasma atmosphere formed inside are prevented from leaking to the passage 20 side. Therefore, a vacuum pressure is applied from the inside of the processing chamber 12 to the front surface of the seal plate 30 that blocks the opening 15, or it is exposed to corrosive gas or plasma existing in the processing chamber 12. Become.

[Seal plate]
As shown in detail in FIG. 2, the seal plate 30 includes a plate body 32, a sealing member 50, a sandwiching plate 40, an attachment screw 36, and the like.
As a specific dimension example of the seal plate 30, a rectangular shape of 225 mm long × 40 mm wide and having a thickness of 12 mm can be used.
<Plate body>
The plate body 32 is made of a metal material such as a SUS material that can withstand the atmosphere and environmental conditions in the processing chamber 12 described above, and has a disk shape having an outer shape corresponding to the shape of the opening 15. In general, it has a rectangular disk shape. The plate main body 32 incorporates the above-described driving mechanism, pressing mechanism, and the like to constitute a gate valve. In the drawing, the structural portion for configuring the plate body 32 as a gate valve is omitted, but it has the same structure as a normal seal plate.

In the plate main body 32, an accommodation recess 33 that accommodates the sandwiching plate 40 is provided on the front surface facing the opening 15. The housing recess 33 has an inverted trapezoidal cross-sectional shape. The inner side surface of the housing recess 33 is tapered to be inclined outward. The planar shape of the housing recess 33 is a rectangular shape that is slightly smaller than the outer shape of the plate body 32.
<Pinch plate>
The sandwich plate 30 is made of the same metal material as that of the plate body 32. The plate is fitted into the receiving recess 33 of the plate body 32. The sandwich plate 30 has a function of sandwiching and attaching the sealing member 50 between the plate body 32.

The attachment plate 36 inserted into the screw insertion hole 35 of the plate body 32 from the back surface of the plate body 32 is screwed into the female screw hole 41 formed in the attachment plate 40, so that the attachment plate 40 is fastened and fixed to the plate body 32. Is done. The front surface position of the sandwiching plate 40 is arranged on the same plane as the front surface position on the outer peripheral side of the plate body 32. The female screw hole 41 is formed only from the back side of the sandwiching plate 40 to the middle in the thickness direction, and the female screw hole 41 and the mounting screw 36 are not exposed on the surface side of the sandwiching plate 40.
In the case of the seal plate 10 having an elongated rectangular shape as described above, the clamping plate 40 can be fixed by the mounting screws 36 at a plurality of positions at a constant pitch interval along the center line in the width direction.

As a specific example of the sandwiching plate 40, a 5 mm thick SUS plate having an outer shape of 3.4 cm × 21.5 cm and having a rectangular shape can be used. Such a sandwiching plate 40 can be fixed to the plate body 32 by arranging the M5 mounting screws 36 at a pitch of 8 cm in the length direction.
<Mounting groove>
On the front side of the plate main body 32, a mounting groove 34 for mounting the sealing member 50 is formed between the inner peripheral edge of the housing recess 33 and the outer peripheral edge of the sandwiching plate 40.
As shown in detail in FIG. 2 (b), the mounting groove 34 is configured to have a concave shape in which the outer peripheral side shape is formed in the plate body 32, and the inner peripheral side shape is formed in the outer end surface 43 of the sandwiching plate 40. The two concave shapes are combined so that the entire cross-sectional shape forms a “convex” character. The mounting groove 34 is provided in an annular shape along the outer periphery of the plate body 32. A sealing member 50 made of a circumferential annular elastic seal material is mounted in the mounting groove 34.

<Sealing member>
The sealing member 50 is formed in an annular shape with the same elastic sealing material as that of a normal O-ring. In this state, the sealing member 50 is composed only of the elastic sealing portion 51.
As shown in detail in FIG. 2 (b), the sealing member 50 includes, in a cross-sectional shape, an approaching / separating part 52 projecting upward, and a groove fitting part 54 projecting to the left and right in the horizontal direction below the contacting / separating part 52 Have
The contact / separation part 52 has a circular arc at the tip. During use, the tip of the contact / separation part 52 comes into contact with the periphery of the opening 15 which is the valve seat surface, and the contact / separation part 52 is elastically deformed to exert a sealing function.

The groove fitting portion 54 is fitted into the mounting groove 34 constituted by the plate main body 32 and the sandwiching plate 40 and fulfills the function of supporting and fixing the sealing member 50 to the plate main body 32 side. The groove insertion portion 54 that is wider than the opening of the convex mounting groove 34 cannot escape from the mounting groove 34.
The bottom surface of the groove insertion portion 54 of the sealing member 50 has a waveform in which the left and right ends and the center protrude downward and the middle is recessed. When the contact / separation portion 53 abuts on the periphery of the opening 15 that is the valve seat surface and a force in the compression direction is applied, the groove insertion portion 54 is deformed so as to expand left and right, or the contact / separation portion 53 extends from the opening 15. A high repulsive force can be generated toward the peripheral side to achieve a high sealing function.

<Air vent hole>
The plate body 32 has an air vent hole 38 penetrating from the bottom surface of the housing recess 33 to the back surface of the plate body 32.
The air vent hole 38 has a small diameter that allows air to flow therethrough, and a plurality of air vent holes 38 are arranged at regular intervals on the entire bottom surface of the housing recess 33. Specifically, for example, the inner diameter of the air vent hole 38 can be set to 1 mm and the number thereof can be set to three.
When the sandwiching plate 40 is arranged at the bottom of the housing recess 33 and is fastened and fixed by the mounting screw 36, the air existing between the bottom surface of the sandwiching plate 40 and the inner bottom surface of the housing recess 33 is discharged. become. The sandwiching plate 40 and the plate body 32 are in close contact with each other and are easily fixed integrally.

<Airtight sealing part>
An O-ring 60 is attached along the outer periphery between the inner bottom surface of the housing recess 33 of the plate body 32 and the lower end surface of the sandwiching plate 40. The O-ring 60 is disposed on the outer peripheral side with respect to the air vent hole 38 described above. The O-ring 60 is an ordinary O-ring made of an elastic seal material or the like, and is mounted in an O-ring groove 31 that is recessed and formed in the inner bottom surface of the housing recess 33. By tightening the mounting screw 36, the outer peripheral side and the inner peripheral side of the O-ring 60 are sealed in an airtight state between the inner bottom surface of the housing recess 33 and the lower end surface of the sandwiching plate 40.
[Assembly of seal plate]
The seal plate 30 having the above structure is assembled by first mounting the O-ring 60 in the O-ring groove 31 in the receiving recess 33 of the plate main body 32, and forming a recess in the inner peripheral edge constituting the outer shape of the mounting groove 34. Arranges the sealing member 50. Since the mounting groove 34 is in a state in which the inner peripheral side is released, the sealing member 50 can be smoothly disposed at a predetermined position without being elastically deformed so much or applying a large external force.

Next, the sandwiching plate 40 is inserted into the housing recess 33 of the plate body 32. Since the outer side surface of the sandwiching plate 40 is inclined in a tapered shape, it fits smoothly into a predetermined position in the center of the housing recess 33 along the slope of the inner surface of the housing recess 33.
The bottom surface of the sandwiching plate 40 contacts the upper end of the O-ring 60. The outer peripheral edge of the sandwiching plate 40 is arranged along the inner peripheral shape of the sealing member 50. The sandwiching plate 40 is in a state of covering the groove insertion portion 54 of the sealing member 50 from above. The contact / separation portion 52 of the sealing member 50 is disposed so as to protrude upward from a space formed between the inner peripheral end of the housing recess 33 of the plate main body 32 and the outer peripheral end of the sandwiching plate 40.
By screwing the mounting screw 36 passed through the screw insertion hole 35 from the back surface of the plate body 32 into the female screw hole 41 of the sandwich plate 40, the sandwich plate 40 is strongly tightened and fixed to the plate body 32 side. Since air existing between the sandwiching plate 40 and the inner surface of the housing recess 33 is discharged from the air vent hole 38 to the back surface of the plate body 32, unnecessary air is interposed between the sandwiching plate 40 and the housing recess 33. It is possible to prevent accumulation or leaving a gap.

Since the bottom surface of the sandwiching plate 40 is strongly pressed against the upper end of the O-ring 60 and the O-ring 60 is deformed, the sealing function of the O-ring 60 is satisfactorily exhibited.
The sealing member 50 is confined in the mounting groove 34 constituted by the outer peripheral edge of the sandwiching plate 40 and the inner peripheral edge of the plate body 32, and cannot be pulled out upward.
In the seal plate 30 assembled as described above, the sealing member 50 is not pushed into the dovetail-shaped mounting groove in advance from a narrow opening like a conventional dovetail sealing ring. Because there is no special shape and structure for smoothly pushing into the dovetail. The relationship between the outer shape of the sealing member 50 and the inner shape of the mounting groove 34 may be designed considering that the hermetic sealing function by the sealing member 50 can be appropriately exhibited when the seal plate 30 is used. There is almost no gap between the outer shape of the sealing member 50 and the inner shape of the mounting groove 34, or a slight gap that allows elastic deformation during use is sufficient.

  Specifically, in FIG. 2B, the groove insertion portion 54 of the sealing member 50 is in contact with the inner surface of the mounting groove 34 at any of the lower surface, the both side surfaces, and the upper surface, or has a very small gap. Not. It is substantially impossible to push the sealing member 50 having such a groove insertion portion 54 into the mounting groove 34 assembled in advance from the upper end opening of the mounting groove 34. However, as described above, one side of the groove insertion portion 54 of the sealing member 50 is inserted into the recess provided in the receiving recess 33 of the plate body 32, and then the outer peripheral edge of the sandwiching plate 40 is inserted into the sealing member 50. If it is only attached so as to cover the side and upper side of the groove insertion portion 54, the sealing member 50 is not excessively deformed, and a state in which the groove insertion portion 54 is fitted in the mounting groove 34 is created. be able to.

[Operation and function of seal plate]
As shown in FIG. 2, the assembled seal plate 30 has basically the same sealing structure as a seal plate in which a circumferential annular sealing member is mounted in a mounting groove of a conventional dovetail structure. is doing. Like a conventional seal plate, it is used by being incorporated into a gate valve or attached to a semiconductor manufacturing apparatus 10.
As shown in FIG. 1, the front end of the sealing member 50 is brought into contact with the outer peripheral edge of the opening 15 that is the valve seat surface, so that the opening 15 is closed and sealed in an airtight state. . As described above, the sealing member 50 mounted without providing an extra gap or margin in the mounting groove 34 efficiently generates a repulsive force against the tightening pressure received from the valve seat surface, and the valve seat surface On the other hand, a strong hermetic sealing action can be exhibited.

Further, by providing an airtight sealing structure by the O-ring 60 between the housing recess 33 of the plate body 32 and the sandwiching plate 40, air or gas that has entered from the screw insertion hole 35 or the air vent hole 38 is Intrusion to the sealing member 50 can be prevented. It is also possible to prevent the vacuum state or gas atmosphere of the processing chamber 12 hermetically sealed by the sealing member 50 from leaking outside through the gap between the sandwich plate 40 and the plate body 32.
When the semiconductor manufacturing apparatus 10 is used, when the opening 15 is closed with the seal plate 30 and the processing chamber 12 is brought into a high vacuum state or a gas atmosphere with strictly regulated control, air is introduced into the seal plate 30. If left behind, the residual air leaks out from the opening 15 into the processing chamber 12 when the processing chamber 12 is depressurized, and the atmosphere of the processing chamber 12 is impaired. In a semiconductor manufacturing processing operation that requires a gas atmosphere controlled with high accuracy, even if a small amount of air is mixed, the operation quality is greatly reduced. Even if the processing chamber 12 is evacuated to a high vacuum state, the target high vacuum state is not maintained until the air remaining between the plate body 32 and the sandwiching plate 40 is sucked into the processing chamber 12 and discharged. Cannot be obtained. It takes a long time to start a processing operation in a high vacuum state, and the work efficiency of semiconductor manufacturing is lowered.

In the case where the seal plate 30 is composed of a plurality of members such as the plate body 32 and the sandwiching plate 40, air is easily trapped in the gaps or spaces between the members, and the above-described problems are likely to occur.
However, if an airtight sealing structure by the O-ring 60 is provided between the plate body 32 and the sandwiching plate 40, air does not leak from the inside of the O-ring 60 to the outside. Even if a small amount of air remains between the plate body 32 and the sandwiching plate 40 outside the O-ring 60, it can be quickly discharged to the processing chamber 12 side. As a result, the processing operation in the atmosphere controlled and controlled with high accuracy in the processing chamber 12 can be performed satisfactorily. The vacuum startup operation of the processing chamber 12 can be achieved quickly, and the workability of semiconductor manufacturing can be improved. Further, at the contact portion or sliding portion between the members such as the screwed portion of the mounting screw 36 for fixing the plate body 32 and the sandwiching plate 40 or the operation mechanism of the seal plate 30, the member is shaved and fine powder is generated. May occur. However, such fine powder cannot enter the space between the sealing member 50 and the mounting groove 34 or the processing chamber 12 side beyond the O-ring 60.

During operation of the semiconductor manufacturing apparatus 10, the inside of the processing chamber 12 is maintained in a high vacuum state, becomes high temperature, becomes a plasma atmosphere, or becomes a corrosive gas atmosphere. The seal plate 30 that closes the opening 15 reliably seals the atmosphere in the processing chamber 12 so as not to leak to the passage 20 side.
Plasma, corrosive gas, high heat, and the like come into contact with the surface of the sealing member 50 and the surface of the sandwich plate 40 from the opening 15. Therefore, the sealing member 50 made of an elastic sealing material is gradually deteriorated. However, since the sandwiching plate 40 is made of a durable metal material or the like, there is no problem.

During the opening operation of the seal plate 30, the sealing member 50 that has been in contact with the outer peripheral edge of the opening 15 may be fixed to the opening 15 side. If the seal plate 30 is opened in this state, the sealing member fixed to the valve seat surface may come out of the dovetail groove only with the conventional sealing member attached to the dovetail groove.
Conventionally, in the case of a normal sealing member that is generally used, after pushing the sealing member elastically deformed from above into the dovetail mounting groove, it can be restored to its original shape A certain amount of gap or margin is provided between the outer shape of the sealing member and the inner shape of the mounting groove so that it can be returned to a predetermined posture. Therefore, when an external force that pulls upward on the sealing member acts strongly, the sealing member floats up or comes out of the mounting groove. A force that pulls only a part of the sealing member is applied, and the sealing member may roll or be distorted in the mounting groove.

However, in this embodiment, since the sealing member 50 is tightly attached to the attachment groove 34 constituted by the plate body 32 and the sandwiching plate 40 with no gap or margin, a large force is generated. Even if added, the sealing member 50 does not come out of the mounting groove 34. The sealing member 50 moves together with the seal plate 30 while being mounted in the mounting groove 34 and is pulled away from the opening 15. The sealing member 50 is not easily pulled out, rolled in the mounting groove 34, or misaligned.
If the opening / closing operation of the seal plate 30 is repeated along with the operation of the semiconductor manufacturing apparatus 10, the service life of the sealing member 50 has passed and it is time to replace it.

In order to replace the sealing member 50, the seal plate 30 is removed from the semiconductor manufacturing apparatus 10, and the sandwiching plate 40 is removed from the seal plate 30. If the sealing member 50 is pulled out from the inner peripheral edge of the housing recess 33 of the plate body 32 to the inner open space after the clamping plate 40 is removed, there is no great resistance, and the sealing member 50 can be easily taken out. Conventionally, the technique and labor required when taking out the sealing ring attached to the dovetail is not required.
The old sealing member 50 taken out is discarded, a new sealing member 50 is attached, and if the sandwiching plate 40 is attached in the same manner as described above, the sealing member 50 is attached to the attachment groove 34, and the seal plate 30 is attached again. Can be used.

[Example of shape change of sealing member (1)]
The embodiment shown in FIG. 3 is different from the above embodiment in the shape of the sealing member 50, that is, the elastic sealing portion 51. Since the basic structure of the seal plate is the same as that of the above embodiment, the difference will be mainly described.
As shown in FIG. 3 (b), the cross-sectional shape of the sealing member 50 composed only of the elastic sealing portion 51 is extended to the left and right under the contact / separation portion 52 protruding in an arc shape and the contact / separation portion 52. And a groove insertion portion 54. The lower end surface of the groove insertion portion 54 is flat and does not have a waveform as in the above embodiment.

The mounting groove 34 formed by the inner peripheral edge of the accommodating recess 33 of the plate body 32 and the outer peripheral edge of the sandwiching plate 40 has a substantially trapezoidal shape. In the outer peripheral side surface 43 of the sandwiching plate 40, a tapered inclined surface corresponding to the inner peripheral side surface of the housing recess 33 forms the inner peripheral wall of the mounting groove 34 as it is. The shape is simpler than that of the above embodiment.
The groove insertion portion 54 of the sealing member 50 is in contact with the mounting groove 34 on the bottom surface and on the left and right sides, and there is no room for the sealing member 50 to move or change its posture inside the mounting groove 34.
Therefore, even in this embodiment, when the seal plate 30 is used, there is a problem that the sealing member 50 is fixed to the opening 15 side and comes out of the mounting groove 34, or the sealing function in a biased posture is lowered. It becomes difficult.

[Sealing member having support plate]
The embodiment shown in FIG. 4 uses a rectangular plate-shaped sealing member 50 composed of an elastic sealing portion and a support plate. Since the basic structure is common to the above-described embodiment, the differences will be mainly described.
The sealing member 50 is made of a metal plate and includes a rigid rectangular plate-like support plate 58, a layered elastic cover portion 56 that covers both surfaces of the support plate 58, and an outer periphery on the upper surface side of the elastic cover portion 56. And an elastic sealing portion 51 integrally formed in a state protruding upward.
As shown in FIG. 4C, the sealing member 50 has circular fitting holes 57 penetrating at three locations in the region inside the elastic sealing portion 51 and spaced in the length direction. Yes. A rectangular meat stealing hole 55 passes through the middle and outside of the fitting holes 57. The fitting hole 57 and the meat stealing hole 55 penetrate both the elastic covering portion 56 and the support plate 58. The fitting hole 57 is used for fixing to the sandwiching plate 40. The meat stealing hole 55 is effective for reducing the weight of the sealing member 50 and reducing the material.

As shown in FIG. 4B, a fitting protrusion 44 projects from the back surface of the sandwiching plate 40 at a position corresponding to the fitting hole 57 of the sealing member 50. Further, at a position close to the outer periphery of the sandwiching plate 40, there is a sealing projection 42 that is arranged in a ring shape and protrudes small upward. The tip of the sealing protrusion 42 is rounded to such an extent that the opposing elastic covering portion 56 is not damaged.
As shown in FIG. 4A, the plate main body 32 has a flat upper surface, and is not provided with an accommodation recess as in the above embodiment. However, the flat upper surface of the plate body 32 has a sealing protrusion 39 having the same shape at a position corresponding to the sealing protrusion 42 of the sandwiching plate 40.
The elastic sealing portion 51 of the sealing member 50 has an outer peripheral side surface that is a vertical surface, an inner peripheral side surface that is an inclined surface, and an upper end that protrudes in an arc shape.

The sealing member 50 is disposed on the upper surface of the plate body 32, and the sandwiching plate 40 is disposed thereon. The sealing member 50 and the sandwiching plate 40 can be positioned by inserting the fitting protrusion 44 of the sandwiching plate 40 into the fitting hole 57 of the sealing member 50. The outer peripheral end surface of the sandwiching plate 40 is an inclined surface corresponding to the inner peripheral side surface of the elastic sealing portion 51 of the sealing member 50. It arrange | positions in the state which the outer peripheral end surface of the clamping board 40 contact | abutted to the inner surface of the elastic sealing part 51. FIG. A part of the elastic sealing portion 51 protrudes above the upper surface of the sandwiching plate 40.
The attachment screw 36 is passed through the screw insertion hole 35 from the back side of the plate body 32, the attachment screw 36 is screwed into the female screw hole 41 of the sandwich plate 40, and the sandwich plate 40 is fastened and fixed to the plate body 32.

At this time, the sealing projection 39 of the plate main body 32 abuts on the elastic coating portion 56 on the back surface side of the sealing member 50, and the sealing projection 42 of the sandwiching plate 40 is elastic coating on the upper surface side of the sealing member 50. It abuts on the part 56. When the sealing protrusions 39 and 42 are strongly pressed against the elastic covering portion 56 and are in a state of being bitten, the inner peripheral side and the outer peripheral side of the sealing protrusions 39 and 42 are hermetically cut off to be in a sealed state. This prevents vacuum and gas from leaking outside through the gap between the sandwich plate 40 and the elastic sealing portion 51 of the sealing member 50. It performs the same function as the O-ring in the embodiment.
In this embodiment, the entire sealing member 50 inside the elastic sealing portion 51 is in a state of being sandwiched between the plate body 32 and the sandwiching plate 40. The sealing member 50 cannot be detached from the seal plate 30. The inner peripheral side of the sealing member 50 is regulated by contact with the outer peripheral end of the sandwiching plate 40, whereas the outer peripheral side of the sealing member 50 is not fixed by the sandwiching plate 40. However, since the support plate 58 of the sealing member 50 is rigid, only the outer peripheral side of the sealing member 50 does not float upward or deform. Since the elastic sealing portion 51 is joined to the support plate 58 integrally with the elastic covering portion 56, only the elastic sealing portion 51 is prevented from being peeled off and separated from the seal plate 30. The

The elastic sealing portion 51 can be deformed relatively freely on the outer peripheral side because the inner peripheral side is restricted and the outer peripheral side is not restricted. As a result, when the opening 15 is sealed with the seal plate 30, the elastic sealing portion 51 can be satisfactorily deformed to generate a strong sealing action.
[Sealing member using metal gasket]
The embodiment shown in FIG. 5 uses a rectangular frame-shaped sealing member 50 having a metal gasket. Since the basic structure is common to the above-described embodiment, the differences will be mainly described.
As shown in FIGS. 5A and 5C, the sealing member 50 has a rectangular frame-shaped support plate 70 made of a metal gasket material. The metal gasket material is made of a relatively soft metal alloy. The center of the support plate 70 is a rectangular fitting hole 72. An elastic sealing portion 51 made of an elastic seal material is disposed along the outer periphery on the upper surface of the support plate 70 and joined to the support plate 70.

5A and 5B, the sandwiching plate 40 has a rectangular plate shape, and has a rectangular shape corresponding to the fitting hole 72 of the support plate 70 of the sealing member 50 at the center on the lower surface side. The fitting protrusion 44 protrudes. The outer peripheral end surface of the sandwiching plate 40 is a vertical surface. A circumferential annular sealing protrusion 42 is provided at a position near the outer periphery on the lower surface of the sandwiching plate 40. The sealing protrusion 42 in this embodiment has a tip that is relatively sharp.
As shown to Fig.5 (a), it has the insertion recessed part 33a in which the sealing member 50 is inserted in the upper surface of the plate main body 32. As shown in FIG. In the center of the inner bottom of the insertion recess 33a, a rectangular insertion hole 37 into which the fitting projection 44 of the sandwiching plate 40 is inserted is provided. The insertion recess 33 a and the insertion hole 37 constitute an accommodation recess for accommodating the sandwich plate 40. On the bottom surface of the fitting recess 33a, outside the fitting hole 37, there is a sealing projection 39 having the same structure facing the sealing projection 42 of the sandwiching plate 40.

The elastic sealing portion 51 of the sealing member 50 has an outer peripheral side surface that is a vertical surface that comes into contact with the insertion recess 33 a of the plate body 32, and an inner peripheral side surface that is a vertical surface that makes contact with the outer peripheral end surface of the sandwiching plate 40. . The center of the elastic sealing portion 51 narrows in a tapered shape from both sides, and the tip protrudes in an arc shape.
For assembling the seal plate 30, the sealing member 50 is inserted into the insertion recess 33 a of the plate main body 32, and the sandwiching plate 40 is disposed at the center thereof.
In the sandwiching plate 40, the fitting projection 44 at the center of the lower surface is fitted into the fitting hole 37 of the plate body 32, and the outer portion of the fitting projection 44 is placed on and held on the support plate 70 of the sealing member 50. become. The outer peripheral side surface of the sandwiching plate 40 abuts on the inner peripheral side surface of the elastic sealing portion 51. The sealing protrusion 42 of the sandwiching plate 40 comes into contact with the upper surface of the support plate 70. The sealing protrusions 39 of the plate body 32 and the sealing protrusions 42 of the sandwiching plate 40 abut both upper and lower surfaces with the support plate 70 interposed therebetween. The upper surface of the sandwiching plate 40 is located slightly higher than the upper surface of the outer peripheral portion of the plate body 32. The upper end of the sealing member 50 protrudes upward from the upper surface of the sandwiching plate 40.

The attachment plate 36 passed through the screw insertion hole 35 from the back surface of the plate body 32 is screwed into the attachment plate 40, whereby the attachment plate 40 is fastened and fixed to the plate body 32.
At this time, the sealing protrusions 42 of the sandwiching plate 40 and the sealing protrusions 39 of the plate body 32 are strongly pressed against the upper and lower surfaces of the support plate 70 made of a metal gasket material, and the sealing protrusions 42, Thus, the outer peripheral side and the inner peripheral side of 39 are hermetically sealed. It is possible to prevent gas or the like from leaking out or entering from the gap between the sandwiching plate 40 and the sealing member 50. Sealing by deformation of the metal gasket material enables sealing with higher airtightness than sealing by a sealing ring such as an O-ring. In particular, since deterioration due to corrosive gas or high heat hardly occurs, it is also suitable for harsh use environments.

When the seal plate 30 is used, the tip of the elastic sealing portion 51 protruding to the front surface comes into contact with the valve seat surface around the opening 15 to perform a sealing function. Even if the elastic sealing portion 51 is fixed to the valve seat surface, the elastic sealing portion 51 fixed to the support plate 70 can be easily separated from the valve seat surface by opening the seal plate 30.
[Example of shape change of sealing member (2)]
The embodiment shown in FIG. 6 uses a sealing member 50 composed only of an elastic sealing portion as in the embodiment of FIG. 1, but the shape is different. Since the basic structure of the seal plate is the same as that of the above embodiment, the difference will be mainly described.

As shown in detail in FIG. 6B, the cross-sectional shape of the elastic sealing portion constituting the sealing member 50 is a relatively large circular contact / separation portion 52, and obliquely inward from the contact / separation portion 52 in the tangential direction. And a relatively small circular locking portion 57 disposed at the lower end of the connection piece 53.
In the mounting groove 34 for mounting the sealing member 50, the outer peripheral end surface of the sandwiching plate 40 is inclined in a tapered shape, and abuts on the inclined inner peripheral surface of the connecting piece 53 of the sealing member 50. The plate body 32 has an accommodation recess 33 in which the sandwiching plate 40 is accommodated. On the inner peripheral surface of the housing recess 33, there is provided a step structure having an upper step 34a having an inclination in which the inner surface spreads from top to bottom, and a lower step 34b further recessed from the upper step 34b inside the upper step 34b. It has been. The inner side surface of the lower step portion 34b is vertical.

When the sealing member 50 is disposed inside the plate main body 32, the contact / separation portion 52 of the sealing member 50 is placed on the upper stage portion 34 a of the plate main body 32. The inclined inner surface of the upper step portion 34 a covers the contact / separation portion 52. The upper end of the contact / separation part 52 protrudes above the upper surface of the plate body 32. The locking portion 57 of the sealing member 50 is disposed on the lower step portion 34 b of the plate body 32. The connecting piece 53 of the sealing member 50 is in a state of being caught by the step portion between the lower step portion 34b and the upper step portion 34a of the plate body 32.
In this state, the sandwiching plate 40 is fitted into the housing recess 33 of the plate body 32. The outer peripheral side surface of the sandwiching plate 40 is disposed along the inner peripheral side surface of the connecting piece 53 of the sealing member 50.

The attachment plate 36 passed through the screw insertion hole 35 from the back surface of the plate body 32 is screwed into the attachment plate 40, whereby the attachment plate 40 is fastened and fixed to the plate body 32.
In a state where the sandwiching plate 40 is fixed to the plate main body 32, the locking portion 57 of the sealing member 50 includes the lower step portion 34 a of the plate main body 32 and the inclined surface of the outer periphery of the sandwiching plate 40 in the mounting groove 34. The connecting piece 53 of the sealing member 50 is sandwiched in a place where the width of the mounting groove 34 is narrowed above. In this state, the sealing member 50 cannot physically come out above the mounting groove 34.
The contact / separation portion 52 of the sealing member 50 has a substantially circular cross section, and can exhibit a good sealing function in the same manner as an O-ring mounted in a normal trapezoidal dovetail.

  In addition, the connecting piece 53 of the sealing member 50 is sandwiched between the corner of the step between the upper step 34 a and the lower step 34 b of the mounting groove 34 and the inclined surface of the outer peripheral end of the sandwiching plate 40. The airtightness of the part increases. In use, when the processing chamber 12 is in a high vacuum state, air remaining between the plate body 32 and the sandwiching plate 40 can be prevented from entering the mounting groove 34. Of course, the function of preventing the gas in the processing chamber 12 from leaking from the mounting groove 34 to the outside of the seal plate 30 is also exhibited.

  The present invention can be applied to, for example, a seal plate incorporated in a gate valve of a semiconductor manufacturing apparatus, and exhibits a high sealing function and can easily replace a sealing member.

The schematic sectional drawing which shows the use condition of the seal plate showing embodiment of this invention Sectional view (a) of seal plate and enlarged sectional view (b) Sectional drawing (a) and principal part expanded sectional view (b) of the seal plate in another embodiment Sectional drawing (a) of the sealing plate in another embodiment, the bottom view (b) of a clamping board, and the top view (c) of a sealing member Sectional drawing (a) of the sealing plate in another embodiment, the bottom view (b) of a clamping board, and the top view (c) of a sealing member Sectional drawing (a) and principal part expanded sectional view (b) of the seal plate in another embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor processing apparatus 12 Processing chamber 15 Opening 20 Passage 30 Seal plate (valve body)
32 Plate body 34 Mounting groove 35 Screw insertion hole 36 Mounting screw 38 Air vent hole 39 Sealing protrusion 40 Clamping plate 50 Sealing member 51 Elastic sealing portion 52 Contacting / separating portion 54 Groove insertion portion 58 Support plate 56 Elastic covering portion 70 Support plate (metal gasket)

Claims (9)

A seal plate that is disposed on the valve body of the valve device and that opens and closes by opening and closing the valve seat surface facing the valve body,
A plate-like plate body facing the opening of the valve seat surface;
A sealing member disposed on the front surface of the plate body facing the valve seat surface, and having an annular elastic sealing portion that contacts and separates from the valve seat surface;
Clamping that is detachably fixed to the front surface of the plate body with a portion of the sealing member sandwiched between the elastic sealing portion and the plate body at a position inside and away from the valve seat surface. The board ,
Equipped with a,
The sandwich plate has a female screw hole provided in the middle of the thickness direction from the surface facing the plate body,
The plate body has a screw insertion hole penetrating the plate body at a position corresponding to the female screw hole of the sandwich plate,
It is screwed into the female screw hole through the screw insertion hole from the back side of the plate body, and includes a mounting screw for fixing the sandwich plate to the plate body.
Seal plate for valve device. The plate body has an accommodation recess into which the sandwich plate is inserted, and the sealing member has a circumferential annular shape with a wider width on the plate body side than a side contacting and separating from the valve seat surface in a cross-sectional shape. An elastic sealing portion, and further configured between an inner peripheral end of the receiving recess and an outer peripheral end of the sandwiching plate, in which the sealing member is stored, and in a cross-sectional shape, the inner side of the front opening side The seal plate for a valve device according to claim 1 , comprising a mounting groove having a wide width. The sealing member is a support plate is sandwiched between the clamping plate and the plate body, and a said resilient sealing section disposed along the outer periphery of the support plate, to claim 1 or 2 Seal plate for the valve device described. The sealing member, and said support plate, said has a resilient sealing portion, and the elastic covering portion formed integrally with the elastic sealing portion covering both sides of the support plate, the valve according to claim 3 Seal plate for equipment. The support plate is made of a metal gasket material, sealing plate for a valve device according to claim 3 or 4. Facing surfaces of the clamping plate and the plate body, the surface facing the the plate body the support plate, either of the opposing surfaces of the support plate and the clamping plate, the inner side than the elastic sealing portion further comprising a hermetic seal portion disposed in a circumferential annular seal plate for a valve device according to either the claims 1 to 5. The hermetic seal portion is disposed on one of the facing surface, and has a sealing projection projecting toward the other side opposite the sealing plate for a valve device according to claim 6. The hermetic seal portion is a arranged O-ring on one of the opposing surfaces, the sealing plate for a valve device according to claim 6. It said plate body has an air vent hole penetrating to the back surface from the surface facing the said clamping plate, sealing plate for a valve device according to either the claims 6 to 8.

Images