JP2006153169A - Sealing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent dusting into a sealing object space and damage by excessive compression of a seal ring 3. <P>SOLUTION: This sealing structure has the seal ring 3 composed of a rubber-like elastic material capable of being brought into close contact with the other member 2 by being fitted in a seal installing groove 12 formed in one member 1 of mutually opposed two members, and a spacer 4 held together with the seal ring 3 in the seal installing groove 12 on the outside of this seal ring 3. The spacer 4 is set larger in rigidity than the seal ring 3, and the projecting height of the spacer 4 to between the two members 1 and 2, is set lower than the projecting height from the seal installing groove 12 of the seal ring 3 in noncompression. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealing structure that is interposed between two opposing members and seals the gap, and is suitable for sealing a reduced pressure space such as a vacuum chamber.

  FIG. 11 is a cross-sectional view schematically showing a vacuum chamber used in processes such as dry etching and sputtering in the manufacture of semiconductor wafers, liquid crystal devices, and the like. This vacuum chamber includes a chamber main body 101 having an exhaust port 101a. The lid 102 is provided at the upper end of the side wall so as to be openable and closable. The space between the opposite ends of the chamber body 101 and the lid 102 is sealed by a seal ring 303, and the internal space S is formed by forced exhaust from the exhaust port 101 a. Is maintained in a vacuum state. Reference symbol W indicates a workpiece (semiconductor wafer, liquid crystal device, or the like) to be processed accommodated in the internal space S of the vacuum chamber.

FIG. 12 is an enlarged cross-sectional view of a part of FIG. 11 as a conventional sealing structure. That is, the seal ring 303 is made of a rubber-like elastic material, and in the illustrated example, the seal ring 303 is fitted into a dovetail seal mounting groove 101c provided around the upper end of the side wall 101b of the chamber body 101, and this seal mounting groove 101c. The portion protruding from the cover 102 is brought into close contact with the end 102 a of the lid 102. Then, by vacuuming the internal space S of the vacuum chamber, the atmospheric pressure P acts to compress the seal ring 303 against the chamber main body 101 and the lid body 102, thereby ensuring the internal space S in a vacuum state. (See Patent Documents 1 and 2, for example).
Japanese Patent Laid-Open No. 2003-14126 JP 2003-240123 A

  Here, in manufacturing a semiconductor wafer, a liquid crystal device, or the like, a slight amount of dust is also avoided. Therefore, generation of metal particles due to metal contact between the upper end of the side wall 101b of the chamber body 101 and the end portion 102a of the lid 102 must be avoided. Don't be. Therefore, the seal ring 303 is also required to have a function of maintaining an appropriate gap G between the upper end of the side wall 101b of the chamber body 101 and the end portion 102a of the lid 102 by the compression reaction force. However, since the seal ring 303 is made of a rubber-like elastic material, the following problems are pointed out.

  First, since the seal ring 303 formed of a rubber-like elastic material causes permanent compression strain (sagging) over time due to continued use, the gap G between the upper end of the side wall 101b of the chamber body 101 and the lid 102 also changes over time. It may be reduced to metal contact.

  Further, as in Patent Document 2, the required clearance G can be maintained by increasing the filling rate of the seal ring 303 in the seal mounting groove 101c and using the seal ring 303 in an overcompressed state. However, in this case, a part of the seal ring 303 subjected to compression loses the escape place and swells and protrudes from the groove shoulder of the seal mounting groove 101c, and is damaged by being bitten between the groove shoulder and the lid 102. Dust generation due to wear may occur.

  Furthermore, in recent years, the size of the vacuum chamber in the liquid crystal device manufacturing apparatus has also increased with the increase in the size of the liquid crystal screen, such as a liquid crystal television monitor, and therefore the load that the seal ring 303 must support has increased. is there. For example, when the planar shape of the sealing portion by the seal ring 303 is a square having a side of 2.5 to 3 m, the compressive load acting on the seal ring 303 reaches about 70 tons when the internal space S of the vacuum chamber is vacuum. Therefore, in order to support such a large load and maintain the gap G, it is necessary to use a seal ring 303 having a large cross-sectional area, and accordingly, the width and depth of the seal mounting groove 101c must be increased. As a result, the size of the vacuum chamber itself must be increased.

  Moreover, when the seal ring 303 is mounted in the dovetail-shaped seal mounting groove 101c as shown in FIG. 12 in order to prevent the dropout, the larger the cross-sectional area of the seal ring 303 and the seal mounting groove 101c, Problems that make it difficult to install are also pointed out.

  The present invention has been made in view of the above points, and its technical problem is that it is possible to effectively prevent the generation of dust into the space to be sealed and the damage caused by over-compression of the seal ring. It is to provide a sealing structure.

  As a means for effectively solving the technical problem described above, the sealing structure according to the invention of claim 1 is fitted into a seal mounting groove formed in one of two members facing each other, and the surface of the other member. A seal ring made of a rubber-like elastic material that can be in close contact with, and a spacer that is outside of the seal ring and is held on one or the other of the two members and is more rigid than the seal ring. The protruding height of the spacer is lower than the protruding height of the seal ring from the seal mounting groove when not compressed.

  In the above configuration, the seal ring fitted in the seal mounting groove formed in one of the two members facing each other exhibits a sealing function by being compressed between the other member. The compression of the seal ring due to the load acting on the two members is limited by the spacer, that is, the reduction of the gap between the two members is limited by the protruding height of the spacer. In addition, since the spacer is disposed outside the seal ring, fine dust generated by contact between the two members and the spacer is blocked from entering the sealed space by the seal ring.

  According to a second aspect of the present invention, in the sealing structure according to the first aspect, the spacer is held in the seal mounting groove together with the seal ring.

  According to a third aspect of the present invention, there is provided the sealing structure according to the second aspect, wherein the seal mounting groove is formed in a dovetail shape and the spacer is fitted to the inclined inner surface of the seal mounting groove. It is.

  According to a fourth aspect of the present invention, in the structure according to the second or third aspect, the inner surface of the spacer facing the seal ring side protrudes larger into the groove toward the insertion end of the seal mounting groove. It is slanted.

  According to the sealing structure of the first to fourth aspects of the present invention, since the reduction of the gap between the two members due to the load acting on the two members facing each other is limited by the spacer, the generation of particles due to the contact of the two members Is prevented, and biting or breakage due to over-compression of the seal ring is also prevented. Further, since the seal ring itself does not require a support function for securing a required gap between the two members, it is not necessary to increase its cross-sectional area. Furthermore, since the spacer is disposed outside the seal ring, fine dust generated from the spacer is blocked from entering the sealed space by the seal ring. For this reason, there exists an outstanding effect as a sealing means of the space which dislikes the penetration | invasion of fine dusts, such as a particle.

  According to the sealing structure of the second aspect of the invention, the spacer is held in the seal mounting groove together with the seal ring, so that the mounting space can be saved.

  According to the sealing structure of the third aspect of the present invention, it is possible to effectively prevent the seal ring and the spacer from falling off from the seal mounting groove.

  According to the sealing structure of the fourth aspect of the present invention, it is possible to facilitate the insertion of the seal ring after inserting the spacer into the seal mounting groove, and when the compression load is applied to the seal ring, the inclination of the spacer Since the compression reaction force due to the pressure contact with the surface is increased and the close contact force of the seal ring to the other member is increased, the sealing performance can be improved.

  Hereinafter, preferred embodiments of a sealing structure according to the present invention will be described with reference to the drawings. 1 is a cross-sectional view schematically showing a first embodiment in which a sealing structure according to the present invention is applied to an opening / closing part of a vacuum chamber together with the vacuum chamber, and FIG. 2 is a plan view taken along line II-II in FIG. 3 is a cross-sectional view in an open state showing a sealing structure according to the first embodiment, and FIGS. 4 and 5 are cross-sectional views in a sealed state showing the sealing structure according to the first embodiment.

  First, the vacuum chamber shown in FIG. 1 is used in processes such as dry etching and sputtering in the manufacture of semiconductor wafers, liquid crystal devices, etc., and has a chamber body 1 having an exhaust port 1a and an opening at its upper end. The lid body 2 is provided so as to be openable and closable. The chamber body 1 corresponds to one of the two members facing each other according to claim 1, and the lid 2 corresponds to the other of the two members.

  A space between the opposed end portions of the chamber body 1 and the lid body 2 is sealed by a seal ring 3, and the internal space S is maintained in a vacuum state by forced exhaust from the exhaust port 1a. Reference symbol W indicates a workpiece (semiconductor wafer, liquid crystal device, or the like) to be processed accommodated in the internal space S.

  The seal ring 3 is formed of a rubber-like elastic material and is not particularly limited as long as it does not easily generate dust. For example, an O-ring having a circular cross-section is used. As shown in FIG. 3, the seal ring 3 is held in a semi-inserted state together with the spacer 4 in the seal mounting groove 12 formed endlessly along the upper end surface 11 a of the side wall 11 of the chamber body 1. .

  As shown in FIG. 2, the upper end surface 11a of the side wall 11 of the chamber body 1 has a substantially square shape with rounded corners. Therefore, the seal mounting groove 12 has a similar shape. Extending.

  The spacer 4 is made of a synthetic resin material such as PTFE, which has higher rigidity than the rubber-like elastic material of the seal ring 3 and has excellent wear resistance, and is formed into a plate having a rectangular cross section. The planar shape is held by linearly extending portions (four locations) of the seal mounting groove 12 having a substantially square shape with rounded corners positioned outside the seal ring 3 (on the side opposite to the internal space S). .

Further, as shown in FIG. 3, the spacer 4 has a length L with respect to the facing direction of the chamber body 1 and the lid body 2 that is smaller than the cross-sectional diameter φ ₃ of the seal ring 3 in the non-compressed state. It is larger than the groove depth d of the groove 12. Therefore, the spacer 4 protrudes by a height h ₄ from the sealing mounting groove 12, the protrusion height h ₄ is lower than the protrusion height h ₃ from the seal mounting groove 12 of the seal ring 3 in the non-compressed It has become.

The protrusion height h ₄ of the spacer 4 from the seal mounting groove 12 is set in consideration of the maximum compression rate (allowable compression rate) of the seal ring 3. That is, if the seal ring 3 is compressed too much, it will crack, so the compression amount of the seal ring 3 between the groove bottom surface 123 of the seal mounting groove 12 and the lower surface 21a of the lid 2 is the maximum compression. not exceed the rate, and as the facing surface 11a of the chamber body 1 and the lid 2, 21a is not metal contact, it is necessary to set the protrusion height h _4. In the case of an O-ring, it is generally recommended that the maximum compression ratio is 30%. Therefore, in the illustrated embodiment in which an O-ring is used as the seal ring 3, the length of the spacer 4 with respect to the facing direction of the chamber body 1 and the lid 2 is long. The length L is preferably 70% or more of the cross-sectional diameter φ ₃ of the seal ring 3.

  The seal mounting groove 12 has an inclined surface in which the inner side surface 121 on the inner space S side is collapsed so as to narrow the groove width on the groove shoulder 121a side, and the inner side surface 122 on the opposite side (outer side) is the groove bottom surface. It stands up perpendicular to 123. The seal ring 3 is fitted in the seal mounting groove 12 so that the center of the cross section is positioned in the groove from the groove shoulders 121a and 122a, and the spacer 4 is connected to the inner surface 122 in the seal mounting groove 12 and the seal ring. 3 is in close contact with the outer peripheral surface 32 in a sandwiched state.

  In the above configuration, as shown in FIG. 1, when the internal space S is evacuated by forcibly exhausting from the exhaust port 1 a with the upper end open portion of the side wall 11 of the chamber body 1 closed with the lid 2. The atmospheric pressure acts to bring the chamber body 1 and the lid 2 close to each other. Therefore, as shown in FIG. 4, a seal is formed between the groove bottom surface 123 of the seal mounting groove 12 formed on the upper end surface 11 a of the side wall 11 of the chamber body 1 and the lower surface 21 a of the end portion 21 of the lid body 2. The ring 3 is compressed, and the sealing reaction necessary to maintain the internal space S in a vacuum state can be ensured by the compression reaction force.

At this time, permanent compression strain (sagging) due to long-term use of the seal ring 3 and an increase in the load from the lid 2 due to atmospheric pressure due to an increase in the size of the vacuum chamber further increase the state shown in FIG. When the end portion 21 of the lid body 2 approaches the upper end surface 11a of the side wall 11 of the chamber body 1 while being compressed, the end portion of the lid body 2 as shown in FIG. The lower surface 21 a of 21 is in contact with and supported by the protruding end 4 a of the spacer 4. Since the spacer 4 is made of a synthetic resin material such as PTFE that is sufficiently stiffer than the seal ring 3, the gap G between the facing surfaces 11a and 21a of the chamber body 1 and the lid 2 is shown in FIG. not be smaller than the protrusion height h ₄ of the spacer 4 shown, the compression of the seal ring 3 is limited to the maximum compression ratio by the spacer 4. Further, the compression amount of the seal ring 3 necessary for maintaining the internal space S in a vacuum state is naturally secured.

  For this reason, generation of metal particles due to metal contact between the opposed end portions 11 and 21 of the chamber body 1 and the lid 2 is prevented, and the spacer 4 is positioned outside the seal ring 3. Particles generated by contact with the end 21 of the body 2 are blocked from entering the internal space S of the chamber by the seal ring 3. Therefore, it is possible to effectively prevent the workpiece W such as the semiconductor wafer or the liquid crystal device shown in FIGS. 1 and 2 from being adversely affected by the particles.

In the sealed state shown in FIG. 4 or FIG. 5, when the seal ring 3 adheres to the inner surface of the end 21 of the lid 2 due to the adhesiveness of the rubber-like elastic material, the vacuum in the internal space S of the chamber When the state is released and the lid 2 is opened from the chamber body 1, the seal ring 3 tries to jump out of the seal mounting groove 12 following the operation of the lid 2. However, as shown in FIG. 3, the seal ring 3 is fitted in the seal mounting groove 12 so that the center O of the cross section thereof is located in the groove with respect to the groove shoulders 121 a and 122 a. A portion 31a of the inner peripheral surface 31 located on the outer side of the groove with respect to the center O of the cross section is locked by being in close contact with the inclined inner side surface 121 (groove shoulder 121a) on the inner space S side in the seal mounting groove 12. is, namely, the cross-sectional diameter phi ₃ of the seal ring 3 is larger than the width between the inner surface 41 of the groove shoulder 121a and the spacer 4, jumping out from the seal mounting groove 12 is effectively prevented.

  Furthermore, according to this embodiment, since the spacer 4 is held in the seal mounting groove 12 together with the seal ring 3, and the spacer 4 is plate-shaped, the mounting space can be kept small.

  Next, FIG. 6 is a sectional view in a sealed state showing a sealing structure according to the second embodiment of the present invention. The second embodiment differs from the first embodiment in that the seal mounting groove 12 is formed in a dovetail shape, and the spacer 4 has a shape that fits with the inclined inner surface 122 of the seal mounting groove 12. It is in. Other configurations are basically the same as those in the first embodiment.

  Specifically, the seal mounting groove 12 is inclined such that the inner side surfaces 121 and 122 facing in the groove width direction expand the groove width on the groove bottom surface 123 side. The width between the groove shoulders 121a and 122a is narrow.

  In addition, the inner surface 41 of the spacer 4 facing the seal ring 3 side rises perpendicularly to the groove bottom surface 123 of the seal mounting groove 12, and the outer surface 42 on the opposite side is the inner surface 122 of the seal mounting groove 12. And has a corresponding inclined surface. Therefore, the spacer 4 gradually increases in thickness from the protruding end 4a toward the insertion end 4b.

  The seal ring 3 is fitted in the seal mounting groove 12 so that the center of the cross section is positioned in the groove from the groove shoulders 121a and 122a, and the spacer 4 has an outer surface 42 on the inner surface of the seal mounting groove 12. The inner surface 41 is in intimate contact with the outer peripheral surface 32 of the seal ring 3 while being fitted between the inclined surfaces 122 and 122.

  Similarly to the first embodiment, in the second embodiment having the above configuration, when the internal space S is evacuated in a state where the upper end open portion of the chamber body 1 is closed by the lid body 2, the side wall 11 of the chamber body 1 is used. The seal ring 3 is compressed between the groove bottom surface 123 of the seal mounting groove 12 formed on the upper end surface 11a and the end portion 21 of the lid 2, and the internal space S is maintained in a vacuum state by the compression reaction force. The sealing required for this is ensured.

  The end 21 of the lid 2 further approaches the upper end surface 11a of the side wall 11 of the chamber body 1 due to an increase in load caused by permanent compression strain of the seal ring 3 and an increase in the size of the vacuum chamber. In this case, the lower surface 21a of the end portion 21 of the lid body 2 comes into contact with the protruding end portion 4a of the spacer 4, and the state shown in FIG. Therefore, generation of metal particles due to metal contact between the opposed surfaces 11a and 21a of the chamber body 1 and the lid 2 is prevented, and particles generated when the spacer 4 comes into contact with the lower surface 21a of the lid 2 enter the chamber internal space S. Is blocked by the seal ring 3, and the compression of the seal ring 3 is limited by the spacer 4 to a maximum compression ratio or less.

  Further, when the seal ring 3 adheres to the lower surface 21a of the lid 2 due to the adhesiveness of the rubber-like elastic material, the vacuum state of the internal space S of the chamber is released and the lid 2 is opened from the chamber main body 1. When doing so, it tries to jump out of the seal mounting groove 12 following the operation of the lid 2. However, since the center of the cross section of the seal ring 3 is located in the groove from the groove shoulders 121a and 122a, the seal ring 3 is located on the outer side of the groove from the center of the cross section on the inner peripheral surface 31 of the seal ring 3. The portion 31a is locked by being in close contact with the inclined inner surface 121 (groove shoulder 121a) on the inner space S side in the seal mounting groove 12, and the cross-sectional diameter of the seal ring 3 is such that the groove shoulder 121a and the inner surface of the spacer 4 Since it is larger than the width between the seal mounting groove 41 and the seal mounting groove 12, it is effectively prevented from popping out.

  Moreover, since the outer surface 42 of the spacer 4 is fitted between the inner surface 122 and the inclined surface of the seal mounting groove 12, when the spacer 4 tries to jump out of the seal mounting groove 12 together with the seal ring 3, It will be pressed against the inner surface 121 of the seal mounting groove 12, and this also contributes to prevention of popping out from the seal mounting groove 12.

  As described above, although the seal ring 3 and the spacer 4 are difficult to jump out of the seal mounting groove 12, when the seal ring 3 and the spacer 4 are mounted on the seal mounting groove 12, the spacer 4 is inserted first, By inserting the seal ring 34, it can be easily mounted.

  Further, according to this embodiment, since the spacer 4 is held in the seal mounting groove 12 together with the seal ring 3, the mounting space can be reduced, and the thickness gradually increases from the protruding end 4a toward the insertion end 4b. Since the shape increases the thickness, high rigidity can be obtained.

  Next, FIG. 7 is a sectional view in a sealed state showing a sealing structure according to a third embodiment of the present invention. In the third embodiment, like the second embodiment shown in FIG. 6, the seal mounting groove 12 is formed in a dovetail shape, and the spacer 4 is fitted to the inclined inner surface 122 of the seal mounting groove 12. There is no. The difference from the second embodiment is that the inner surface 41 of the spacer 4 that is in close contact with the outer peripheral surface 32 of the seal ring 3 is inclined so as to protrude into the groove as far as the insertion end 4b side into the seal mounting groove 12 is. ing.

  Similarly to the first embodiment, in the third embodiment having the above configuration, when the internal space S is evacuated in a state where the upper end open portion of the chamber body 1 is closed by the lid body 2, the side wall 11 of the chamber body 1 is formed. The seal ring 3 is compressed between the groove bottom surface 123 of the seal mounting groove 12 formed on the upper end surface 11a and the end portion 21 of the lid 2, and the internal space S is maintained in a vacuum state by the compression reaction force. The sealing required for this is ensured.

  In addition, since the inner side surface 41 of the spacer 4 is inclined so as to protrude into the groove as far as the insertion end 4b side, the inner side surface of the spacer 4 as the seal ring 3 is displaced into the groove by compression. The pressure contact force with 41 also increases, and the reaction force acts so as to increase the close contact force with the inner side surface of the lid 2, so that even better sealing performance is achieved.

  Further, the end 21 of the lid 2 is further brought closer to the upper end surface 11a of the side wall 11 of the chamber body 1 due to the permanent compression strain of the seal ring 3 and the increase in load due to the increase in the size of the vacuum chamber. In this case, the lower surface 21a of the lid body 2 comes into contact with the protruding end portion 4a of the spacer 4, and the state shown in FIG. Therefore, generation of metal particles due to metal contact between the facing surfaces 11a and 21a of the chamber body 1 and the lid body 2 is prevented, and particles generated when the spacer 4 comes into contact with the lower surface 21a of the lid body 2 enter the chamber internal space S. Is blocked by the seal ring 3, and the compression of the seal ring 3 is limited by the spacer 4 to a maximum compression ratio or less.

  Further, since the center of the cross section of the seal ring 3 is located in the groove from the groove shoulders 121a and 122a, the seal ring 3 is located on the outer side of the groove from the center of the cross section on the inner peripheral surface 31 of the seal ring 3. The portion 31a is locked by being brought into close contact with the inclined inner surface 121 (groove shoulder 121a) on the inner space S side in the seal mounting groove 12, so that the protrusion from the seal mounting groove 12 is effectively prevented.

  Moreover, the outer surface 42 of the spacer 4 is fitted between the inner side surface 122 and the inclined surface in the seal mounting groove 12, and the inner side surface 41 that is in close contact with the seal ring 3 protrudes toward the insertion end 4 b side. Therefore, when it tries to jump out from the seal mounting groove 12 together with the seal ring 3, the inclined inner side surface 41 acts to press the seal ring 3 against the inner side surface 121 of the seal mounting groove 12. Therefore, this also contributes to prevention of popping out from the seal mounting groove 12.

  Although the seal mounting groove 12 has a dovetail shape, the seal ring 3 and the spacer 4 are made difficult to jump out. Therefore, it can be easily mounted by inserting the seal ring 34. This is because the inner surface 41 of the spacer 4 is inclined so as to open in the direction in which the inner surface 121 of the seal mounting groove 12 falls, so that the substantial seal ring insertion space in the seal mounting groove 12 becomes the groove inlet side. This is because the seal ring 34 is guided to the left side in FIG. 7 by the inner side surface 41 of the spacer 4 when the seal ring 34 is inserted into the seal mounting groove 12. .

  Furthermore, according to this embodiment, as in the second embodiment, the mounting space can be kept small, and the thickness gradually increases from the protruding end 4a toward the insertion end 4b. Can be obtained.

  Next, FIG. 8 is a sectional view in a sealed state showing a sealing structure according to a fourth embodiment of the present invention, and FIG. 9 is a plan view. This fourth embodiment is different from the above-described embodiments in that the spacer 4 is mounted in a spacer mounting groove 13 formed separately from the seal mounting groove 12.

  That is, as shown in FIG. 9, the seal mounting groove extending endlessly on the upper end surface 11 a of the side wall 11 of the chamber body 1 so that the planar shape forms a substantially square with rounded corners along the extending direction. 12 and four linear spacer mounting grooves 13 located on the outer peripheral side of the linear portion are formed.

  As shown in FIG. 8, the seal mounting groove 12 has an inclined surface in which the inner surface 121 on the inner space S side collapses so as to narrow the groove width on the groove shoulder 121 a side, and the opposite side (outer side). The inner side surface 122 of the groove rises perpendicularly to the groove bottom surface 123. The seal ring 3 made of rubber-like elastic material is fitted into the seal mounting groove 12 in a half-inserted state so that the center of the cross section is located in the groove from the groove shoulders 121a and 122a. The portion 31a located on the outer side of the groove from the center of the cross section is in close contact with the inclined inner surface 121 (groove shoulder 121a) on the inner space S side in the seal mounting groove 12, and the outer peripheral surface 32 is the seal mounting groove 12. In close contact with the vertical inner surface 122.

  The spacer 4 is made of a synthetic resin material such as PTFE having higher rigidity than the rubber-like elastic material of the seal ring 3 and excellent in wear resistance. In the half-inserted state in the groove 13, it is fixed via an adhesive (not shown) or a bolt. That is, each spacer 4 is located outside the seal ring 3 (opposite to the internal space S), and the protruding height of the spacer 4 from the spacer mounting groove 13 is the seal mounting of the seal ring 3 when not compressed. The protrusion height from the groove 12 is lower. In the embodiment of FIG. 8 in which an O-ring is used as the seal ring 3, the compression amount of the seal ring 3 between the groove bottom surface 123 of the seal mounting groove 12 and the lower surface 21a of the lid 2 is the maximum compression rate. And the height (length L) from the groove bottom surface 123 to the upper surface of the spacer 4 is set to be a cross section of the seal ring 3 so that the opposed surfaces 11a and 21a of the chamber body 1 and the lid 2 do not contact each other. It is preferable to be 70% or more of the diameter.

  In the fourth embodiment having the above configuration, basically, the internal space S is evacuated in a state where the upper end open portion of the side wall 11 of the chamber body 1 is closed by the lid body 2 as in the above-described embodiments. Then, the seal ring 3 is compressed between the groove bottom surface 123 of the seal mounting groove 12 of the chamber body 1 and the lower surface 21a of the lid body 2 by the atmospheric pressure acting on the lid body 2, and the compression reaction force The sealing property required to maintain the internal space S in a vacuum state is ensured.

  Further, the end of the lid 2 is further extended with respect to the upper end surface 11a of the side wall 11 of the chamber body 1 due to the permanent compression distortion of the seal ring 3 and the increase in the load from the lid 2 due to the increase in the size of the vacuum chamber. When the portions 21 are close to each other, the lower surface 21a of the lid 2 abuts against the spacer 4 and is supported in the state shown in FIG. For this reason, generation of metal particles due to metal contact between the opposed surfaces 11a and 21a of the chamber body 1 and the lid 2 is prevented, and the chamber internal space of particles generated when the spacer 4 comes into contact with the end portion 21 of the lid 2 is prevented. The intrusion into S is blocked by the seal ring 3, and the compression of the seal ring 3 is further limited to a maximum compression ratio or less by the spacer 4.

  In the sealed state shown in FIG. 8, when the seal ring 3 adheres to the lower surface 21a of the lid 2 due to the adhesiveness of the rubber-like elastic material, the vacuum state of the internal space S of the chamber is released and the lid is released. When opening 2 from the chamber body 1, the seal ring 3 tries to jump out of the seal mounting groove 12 following the operation of the lid 2. However, in the seal ring 3, a portion 31a of the inner peripheral surface 31 positioned on the outer side of the groove with respect to the center of the cross section is an inclined inner side surface 121 (groove shoulder 121a) on the inner space S side in the seal mounting groove 12. Since the cross-sectional diameter of the seal ring 3 is larger than the width between the groove shoulders 121a and 122a, the protrusion from the seal mounting groove 12 is effectively prevented.

  Next, FIG. 10 is a sectional view in a sealed state showing a sealing structure according to a fifth embodiment of the present invention. In the fifth embodiment, the spacer mounting groove 13 is formed in a dovetail shape, and the cross-sectional shape of the spacer 4 is formed in a substantially trapezoidal shape that can be fitted into the spacer mounting groove 13. Is the same as the fourth embodiment shown in FIG.

  Therefore, the same effect as that of the fourth embodiment shown in FIG. 8 is realized, and an adhesive, a bolt, and the like for fixing the spacer 4 to the spacer mounting groove 13 can be made unnecessary.

  In each of the illustrated embodiments, the seal mounting groove 12 or the spacer mounting groove 13 is formed on the upper end surface 11a of the side wall 11 of the chamber body 1, that is, the seal ring 3 and the spacer 4 are mounted on the chamber body 1 side. However, conversely, the seal mounting groove 12 or the spacer mounting groove 13 may be formed on the lid body 2 side, that is, the seal ring 3 and / or the spacer 4 may be held on the lid body 2 side.

It is sectional drawing which shows schematically the 1st form of the sealing structure which concerns on this invention with a vacuum chamber. It is a top view on the II-II line in FIG. It is sectional drawing of the open state which shows the sealing structure by the 1st form which concerns on this invention. It is sectional drawing of the sealing state which shows the sealing structure by the 1st form which concerns on this invention. It is sectional drawing of the sealing state (contact state of a spacer) which shows the sealing structure by the 1st form which concerns on this invention. It is sectional drawing of the sealing state (contact state of a spacer) which shows the sealing structure by the 2nd form which concerns on this invention. It is sectional drawing of the sealing state (contact state of a spacer) which shows the sealing structure by the 3rd form which concerns on this invention. It is sectional drawing of the sealing state (contact state of a spacer) which shows the sealing structure by the 4th form which concerns on this invention. It is a top view which shows the sealing structure by the 4th form which concerns on this invention. It is sectional drawing of the sealing state (contact state of a spacer) which shows the sealing structure by the 5th form which concerns on this invention. It is sectional drawing which shows roughly the vacuum chamber used in manufacture of a semiconductor, a liquid crystal, etc. It is sectional drawing which expands and shows a part of FIG. 11 as a sealing structure by a prior art.

Explanation of symbols

1 Chamber body (one of two members)
DESCRIPTION OF SYMBOLS 1a Exhaust port 11 Side wall 11a Upper end surface 12 Seal mounting groove 121,122 Inner side surface 121a, 122a Groove shoulder 123 Groove bottom surface 13 Spacer mounting groove 2 Lid (the other member of two members)
21 End 21a Lower surface 3 Seal ring 31 Inner peripheral surface 32 Outer peripheral surface 4 Spacer 4a Projecting end 4b Insertion end 41 Inner side 42 Outer side S Internal space W Workpiece

Claims (4)

A seal ring (3) made of a rubber-like elastic material that is fitted in a seal mounting groove (12) formed in one of two members (1, 2) facing each other and can be in close contact with the other, and this seal ring (3 ) And a spacer (4) which is held on one or the other of the two members (1, 2) and has a rigidity higher than that of the seal ring (3), and between the two members (1, 2). the protrusion height of the spacers (4) of (h ₄₎ is the feature is lower than the protruding height from the seal mounting groove of the sealing ring in the non-compressed (3) (12) (h ₃₎ Sealing structure to do.   The sealing structure according to claim 1, wherein the spacer (4) is held in the seal mounting groove (12) together with the seal ring (3).   The seal mounting groove (12) is formed in a dovetail shape, and the spacer (4) is shaped to fit with the inclined inner surface (122) of the seal mounting groove (12). The sealing structure described.   The inner surface (41) facing the seal ring (3) side of the spacer (4) is inclined so that it protrudes into the groove as far as the insertion end (4b) side into the seal mounting groove (12). The sealing structure according to claim 2 or 3, characterized in that

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