JP2009144735A - Sealing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a seal-ring 3 from being damaged or causing dust by a plasma within a sealed space S or corrosive fluid, or from being broken by excessive compression. <P>SOLUTION: A sealing structure comprises a dovetail seal attaching groove 12, the seal-ring 3 in which side surface expansion sections 3a, 3b are held within this seal attaching groove 12, and a head section 3d consists of rubber-like elastic material projected from the seal attaching groove 12, and a spacer 4 which is held in the seal attaching groove 12 and located at sealed space S side, and consists of a material greater in durability than the seal-ring 3. Furthermore, the spacer 4 comprises a collar section 41 supported on a groove shoulder 124 of the sealed space S side of the seal attaching groove 12, and a groove inner-side inserting section 42 fitted in an inner-side surface 122 of the seal attaching groove 12 and pushing the side surface expansion section 3b of the seal-ring 3 to an inner-side surface 123 of the groove shoulder 125 on the side opposite to the sealed space and a shoulder section 43 between the collar section 41 and the groove inner-side inserting section 42. Additionally, the thickness t of the collar section 41 is smaller than a projection height h<SB>1</SB>from the seal attaching groove 12 of the seal-ring 3 when non-compressing. <P>COPYRIGHT: (C)2009,JPO&INPIT

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.

  6 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 and liquid crystal display devices, and FIG. 7 shows a sealing structure according to the prior art as shown in FIG. FIG. 8 is a cross-sectional view showing a part of the enlarged view, and FIG. 8 is a view for explaining a problem in the conventional sealing structure shown in FIG.

  The vacuum chamber shown in FIG. 6 includes a chamber main body 101 having an exhaust port 101a and a lid body 102 that can be opened and closed at the upper end of the side wall, and a seal between the opposite ends of the chamber main body 101 and the lid body 102 is provided. The inner space S is sealed by the ring 103 and maintained in a vacuum state by forced exhaust from the exhaust port 101a. Reference numeral WK indicates a workpiece (semiconductor wafer, liquid crystal panel substrate, or the like) to be processed that is accommodated in the internal space S of the vacuum chamber.

  In the example shown in FIG. 7, the seal ring 103 is an O-ring made of a rubber-like elastic material, and is fitted into a seal mounting groove 101 c provided around the upper end of the side wall 101 b of the chamber body 101, and this seal mounting groove 101 c. A portion protruding from the cover 102 is brought into close contact with the lid 102. Then, by evacuating the internal space S of the vacuum chamber, as shown in FIG. 6, the atmospheric pressure P acts to compress the seal ring 103 against the chamber body 101 and the lid 102, and the internal space The seal required to secure S in a vacuum state is obtained. Further, the seal mounting groove 101c has a groove width on the shoulder side of the groove that is narrower than the cross-sectional diameter of the seal ring 103 and a relative groove width on the bottom side of the groove in order to prevent the seal ring 103 from falling off when the lid 102 is opened and closed. It is formed in a dovetail shape having a pair of inner sloped surfaces inclined so as to become wider.

  However, in the sealing structure as shown in FIG. 7, since the seal mounting groove 101c is formed in the shape of a dovetail, it is difficult to mount the seal ring 103, and it is possible to forcefully push it into the seal mounting groove 101c. There is a concern that the seal ring 103 is mounted in a twisted state and the sealing performance is deteriorated.

  In manufacturing a semiconductor device or a liquid crystal display device, there is a process of processing the surface of a semiconductor wafer or a liquid crystal panel substrate with plasma in a vacuum chamber such as plasma etching or sputtering, as shown in FIG. The rubber-like elastic material of the seal ring 103 may be damaged when the plasma PZ in the vacuum chamber is incident on the seal ring 103. In this case, not only the sealing performance of the seal ring 103 is lost, but also particles may be generated to adversely affect the product.

  In recent years, with the increase in the size of liquid crystal display devices such as liquid crystal television monitors, the size of the vacuum chamber in the device for manufacturing the liquid crystal display device has also increased. The compressive load received also tends to increase. In order to obtain a sufficient reaction force against this compressive load, it is effective to increase the filling rate of the seal ring 103 in the seal mounting groove 101c. In this case, as shown in FIG. A portion 103a of the seal ring 103 subjected to compression swells from the groove shoulder of the seal mounting groove 101c and protrudes to the vacuum side (inside the internal space S), and is damaged by being bitten between the groove shoulder and the lid 102, This may generate particles.

  In addition, when the filling rate of the seal ring 103 in the seal mounting groove 101c is not so large, the gap between the side wall of the chamber body 101 and the lid body 102 decreases with time due to permanent compression strain of the rubber-like elastic material. As shown in FIG. 8C, there is a possibility that metal touch is caused and metal particles are generated by repeating the metal touch.

On the other hand, as this type of sealing structure, techniques such as the following patent documents are disclosed. These all have a structure in which a seal ring (first seal member) made of a rubber-like elastic material and a spacer (second seal member) made of a synthetic resin are held in a dovetail seal mounting groove. is there.
JP 2005-164027 A JP 2006-153169 A

  However, in the sealing structure disclosed in Patent Document 1, when the second seal member made of synthetic resin is subjected to compressive deformation due to a large compressive load, the second seal member is also made of a rubber-like elastic material. Since it is pushed into the seal mounting groove together with the one seal member, metal touch cannot be prevented. And since the cross-sectional shape of a sealing member is unusual, when it is attached reversely, required sealing performance cannot be ensured. Further, since the first seal member and the second seal member are completely in close contact with each other, there is a problem that there is little escape space for the seal member when subjected to compression, and the reaction force becomes too large due to overcompression. is there.

  Further, in the sealing structure disclosed in Patent Document 2, since the spacer made of synthetic resin is mounted on the atmosphere side of the seal ring made of rubber-like elastic material, the seal ring by plasma PZ as shown in FIG. It was not possible to prevent damage to the surface and the protrusion of the seal ring as shown in FIG. 8B to the vacuum side.

  The present invention has been made in view of the above points, and its technical problem is that the seal ring is damaged by plasma or corrosive fluid in the space to be sealed, or the seal ring is broken by over-compression. Another object of the present invention is to provide a sealing structure that can eliminate the problem of dust generation due to contact on both sides of the seal ring.

  As means for effectively solving the technical problem described above, the sealing structure according to the invention of claim 1 includes a dovetail-shaped seal mounting groove formed on one of two opposing members, and a side bulge. A seal ring made of a rubber-like elastic material whose head is protruded from the seal mounting groove and in which the head protrudes from the seal mounting groove can be in close contact with the other of the two members; A spacer made of a material that is held on the sealing target space side and is more rigid than the seal ring, and the spacer is supported on a groove shoulder on the sealing target space side of the seal mounting groove, An in-groove insertion portion that is fitted to the inner side surface of the seal mounting groove on the space to be sealed side and presses the side bulge portion of the seal ring against the inner surface on the anti-sealing target space side, and the flange portion and the in-groove insertion Between clubs Consists shoulder, the thickness of the flange portion is characterized in that less than the projection height from the seal mounting groove of said seal ring when uncompressed.

  In the above configuration, the seal ring held in the seal mounting groove formed on one of the two members facing each other exhibits a sealing function by being compressed between the other member. Then, the spacer held in the seal mounting groove is configured such that the insertion portion in the groove presses the side bulging portion of the seal ring against the inner surface of the seal mounting groove on the anti-sealing target space side so that the seal ring is sealed in a dovetail shape. The function of locking to the mounting groove and the compression of the seal ring due to the load acting on the two members are supported on the groove shoulder on the sealing target space side of the seal mounting groove and interposed between the other member. The function of limiting by the flange, in other words, the function of limiting the reduction in the gap between the two members due to the load, the protrusion of the seal ring to the sealed space side, and the sealing of plasma or corrosive fluid on the sealed space side It has the function of blocking the incidence on the ring by the flange.

  According to a second aspect of the present invention, there is provided the sealing structure according to the first aspect, wherein the width between the shoulders of the seal mounting groove is larger than the width between the side bulging portions of the seal ring and is held in the seal mounting groove. It is assumed that the width between the shoulder portion of the spacer and the groove shoulder facing the spacer is smaller than the width between the side bulge portions. If configured in this way, the width between the groove shoulders, which is the minimum width portion of the dovetail seal mounting groove, is larger than the width between the side bulging portions, which is the maximum width portion of the seal ring. The seal ring is easily inserted into the seal mounting groove in advance, and then inserted into the seal mounting groove and fitted into the seal mounting groove, so that the seal ring is sealed by the spacer shoulder and the groove shoulder facing it. Can be locked to.

  According to a third aspect of the present invention, the sealing structure according to the first aspect of the present invention is such that the inner surface of the spacer insertion portion in the groove facing the seal ring side protrudes into the seal mounting groove as the shoulder portion increases. Inclined. If comprised in this way, a seal ring can be reliably latched to a seal | sticker installation groove | channel by the shoulder part of a spacer, and the groove | channel shoulder facing this.

  According to a fourth aspect of the present invention, there is provided the sealing structure according to the first aspect, wherein the fitting surface between the seal mounting groove and the in-groove insertion portion of the spacer is substantially perpendicular to the opposing surfaces of the two members. Standing up. If comprised in this way, after inserting a seal ring in a seal | sticker mounting groove ahead of a spacer, the insertion part in a groove | channel of a spacer can be easily mounted | worn in a seal | sticker mounting groove.

  According to a fifth aspect of the present invention, there is provided the sealing structure according to the first aspect, wherein the groove shoulder on the sealing target space side of the seal mounting groove is lower than the groove shoulder on the anti-sealing target space side, The wall thickness is larger than the difference in height between the two shoulders. If comprised in this way, the crushing margin of a seal ring can be enlarged, after restrict | limiting the reduction | decrease of the clearance gap between two members by the compressive load to a seal ring.

  The sealing structure according to the invention of claim 6 is characterized in that, in the structure of claim 1, the spacer is made of PTFE (polytetrafluoroethylene). Since PTFE is excellent in plasma resistance, corrosion resistance and wear resistance, dust generation from the spacer can be effectively suppressed.

  According to the sealing structure of the present invention, since the seal ring is locked to the seal mounting groove by the spacer, it is easy to mount the seal ring to the seal mounting groove, and compression of the seal ring is ensured by the flange portion of the spacer. Therefore, it is possible to prevent damage to the seal ring due to over-compression or dust generation due to contact on both sides of the seal ring, and the seal ring protrudes into the space to be sealed, and plasma and corrosion on the space to be sealed The seal ring can be prevented from being damaged by the sexual fluid.

  Hereinafter, preferred embodiments of a sealing structure according to the present invention will be described with reference to the drawings. FIG. 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 an opening showing a sealing structure according to the first embodiment. FIG. 3 is a sectional view of the 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 plasma etching and sputtering in the manufacture of semiconductor components, liquid crystal display devices, and the like, and includes a chamber body 1 having an exhaust port 1a and an upper end opening portion thereof. And a lid body 2 that can be opened and closed. The chamber body 1 and the lid body 2 correspond to the two members facing each other as described in claim 1.

  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 numeral WK indicates a workpiece to be processed (semiconductor wafer or substrate of a liquid crystal panel) accommodated in the internal space S. The internal space S corresponds to the sealed space described in claim 1.

  As shown in FIG. 2, the seal ring 3 is held together with the spacer 4 in a seal mounting groove 12 formed endlessly along the upper end surface 11 a of the side wall 11 of the chamber body 1.

Specifically, the seal mounting groove 12 is formed in a dovetail cross-sectional shape, that is, has a flat groove bottom 121 and inner side surfaces 122 and 123 that are inclined so as to fall in opposite directions from both sides thereof. . Therefore, the groove width w ₁ on the groove bottom 121 side of the seal mounting groove 12 is relatively wide, and the groove width w ₂ between the groove shoulders 124 and 125 is relatively narrow.

  The seal ring 3 is formed of a rubber-like elastic material, and is formed of, for example, an O-ring having a circular cross-sectional shape. 12 is fitted in a half-inserted state. That is, the side bulging portions 3a, 3b on the left and right sides in the circular cross section of the seal ring 3 are held in the seal mounting groove 12, and the lower portion 3c in the circular cross section is in close contact with the groove bottom 121 of the seal mounting groove 12, The head 3 d in the cross section protrudes outside the seal mounting groove 12.

  The spacer 4 is made of a material having higher rigidity than the rubber-like elastic material of the seal ring 3 and excellent in plasma resistance, corrosion resistance, and wear resistance, for example, PTFE. It is positioned and held inside the ring 3 (inside the internal space S).

Specifically, the spacer 4 is fitted to the flat plate-like flange portion 41 supported on the groove shoulder 124 on the inner space S side in the seal mounting groove 12 and the inner side surface 122 on the inner space S side in the seal mounting groove 12. A groove which is brought into contact with the seal ring 3 and presses the side bulging portion 3b against the groove shoulder 125 or the inner side surface 123 on the side opposite to the inner space S (corresponding to the anti-sealing target space side according to claim 1). It consists of an inner insertion portion 42 and a shoulder 43 between the flange portion 41 and the in-groove insertion portion 42. Of these, the in-groove insertion portion 42 has an inclined shape corresponding to the inner side surface 122 on the inner space S side in the seal mounting groove 12, and the inner side surface 42 a facing the seal ring 3 side has a shoulder portion 43. It inclines so that it may protrude in the seal | sticker installation groove | channel 12 so that it may be large in the side. Further, the thickness t of the flange portion 41, the head 3d of the sealing ring 3 when uncompressed, has become smaller than the protrusion height h ₁ from the seal mounting groove 12.

Further, the groove width w ₂ between the groove shoulders 124 and 125 in the seal mounting groove 12 is larger than the width (cross-sectional diameter) w ₃ between the side surface bulging portions 3 a and 3 b of the seal ring 3 and is held in the seal mounting groove 12. Further, the width w ₄ between the shoulder 43 of the spacer 4 and the groove shoulder 125 opposed thereto is smaller than the width (cross-sectional diameter) w ₃ between the side bulged portions 3a and 3b.

  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. 3, the seal ring 3 is compressed between the groove bottom 121 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 2 a of the lid 2. The sealing reaction necessary to maintain the internal space S in a vacuum state is ensured by the compression reaction force.

  At this time, the seal ring 3 is further compressed from the state shown in FIG. 3 due to permanent compression strain (sagging) due to long-term use of the seal ring 3 and compression load from the chamber body 1 and the lid 2 due to atmospheric pressure. However, when the lid body 2 approaches the upper end surface 11 a of the side wall 11 of the chamber body 1, the lower surface 2 a of the lid body 2 comes into contact with and is supported by the flange portion 41 of the spacer 4. Since the spacer 4 is made of PTFE having sufficiently higher rigidity than the seal ring 3, a gap G between the upper end surface 11a of the side wall 11 of the chamber body 1 and the lower surface 2a of the lid 2 is shown in FIG. The thickness t of the flange portion 41 of the spacer 4 is never smaller, and therefore, generation of metal particles due to metal touch between the upper end surface 11a of the side wall 11 of the chamber body 1 and the lower surface 2a of the lid 2 is prevented, It is possible to effectively prevent the adverse effect of the metal particles on the workpiece WK (see FIG. 1). Further, the compression rate of the seal ring 3 is limited to an appropriate range by the spacer 4, and the crushing margin Q of the seal ring 3 necessary for maintaining the internal space S in a vacuum state is secured.

  Further, even if a plasma processing gas used in a process such as plasma etching or sputtering for processing the surface of a substrate of a semiconductor wafer or a liquid crystal panel is generated in the internal space S, it is made of PTFE having excellent plasma resistance. Since the flange portion 41 of the spacer 4 is interposed between the upper surface (upper end surface 11a) of the groove shoulder 124 and the lower surface 2a of the lid body 2 on the inner space S side from the seal ring 3, it seals from the inner space S. The incidence of plasma on the ring 3 is effectively blocked. Therefore, it is possible to prevent the seal ring 3 from being damaged by the plasma and the sealing performance from being lost, and to effectively prevent the plasma from generating particles from the seal ring 3 and adversely affecting the work WK (see FIG. 1). be able to.

  Moreover, the protrusion of the seal ring 3 from the seal mounting groove 12 to the inner space S side by evacuating the inner space S of the chamber is closer to the inner space S side than the seal ring 3 and the upper surface of the groove shoulder 124 and the lid 2. Therefore, the seal ring 3 is effectively prevented from being damaged due to the protrusion.

Here, in the sealed state shown in FIG. 3, when the seal ring 3 adheres to the lower surface 2a 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 released. Is opened from the chamber body 1, the seal ring 3 tends to come out of the seal mounting groove 12 following the operation of the lid 2. However, as shown in FIG. 2, the width w ₄ between the shoulder 43 of the spacer 4 held in the seal mounting groove 12 and the groove shoulder 125 opposite to the shoulder 43 is the side bulging portions 3 a and 3 b of the seal ring 3. width between smaller than the (cross-sectional diameter) w _3, spacer 4, have been fitted with the inclined faces of the groove in the insertion portion 42 correspond to each other on the inner surface 122 of the inner space S side of the seal fitting groove 12, Since the side bulging portions 3a and 3b of the seal ring 3 are locked by being pressed against the inclined inner side surface 42a of the in-groove insertion portion 42 and the inclined inner side surface 123 of the seal mounting groove 12, the seal mounting groove 12 Popping out from the is effectively prevented.

The larger width (cross-sectional diameter) _{w 3} between the side surfaces bulging portion 3a, 3b width _{w 2} between the groove shoulder 124 and 125 is the most significant portion of the seal ring 3 is the minimum width portion of the seal mounting groove 12 Therefore, when the seal ring 3 is mounted, it can be easily mounted without forcibly pushing it by inserting it into the seal mounting groove 12 prior to the spacer 4, so that it can be mounted in a twisted state. Absent. Then, after the seal ring 3 is inserted, the in-groove insertion portion 42 of the spacer 4 is inserted and fitted into the seal mounting groove 12, so that the seal ring 3 is connected by the shoulder portion 43 of the spacer 4 and the groove shoulder 125 of the seal mounting groove 12. Is firmly locked in the seal mounting groove 12.

  Next, FIG. 4 is an open sectional view showing a sealing structure according to the second embodiment of the present invention.

The second differs from the first embodiment described above where the embodiment, the height of the groove shoulder 125 height h ₂ of the internal space S opposite to the inner space S side of the groove shoulder 124 of the seal mounting groove 12 h _{3 and the} thickness t of the flange 41 of the spacer 4 is larger than the difference Δh between the heights h ₂ and h ₃ of the groove shoulders 124 and 125. Further, the thickness t of the flange 41 is set to be smaller than the protruding height h ₁ ′ of the head 3d of the seal ring 3 from the groove shoulder 124 on the inner space S side when not compressed. Other configurations are basically the same as those in the first embodiment.

  Therefore, according to the second embodiment, the same operation and effect as in the first embodiment can be obtained, and the thickness t of the flange portion 41 of the spacer 4 can be set, for example, as described above with reference to FIG. When it is the same as that of the portion 41, the crushing margin Q of the seal ring 3 can be increased by Δh as compared with that of FIG.

  Next, FIG. 5 is a sectional view in an open state showing a sealing structure according to a third embodiment of the present invention.

  The third embodiment is different from the first embodiment described above in that the fitting surface between the seal mounting groove 12 and the in-groove insertion portion 42 of the spacer 4 is formed between the chamber body 1 and the lid body 2 shown in FIG. In other words, they stand up substantially perpendicular to the opposing surfaces, in other words, the upper end surface 11a of the side wall 11 of the chamber body 1 shown in FIG. Other configurations are basically the same as those in the first embodiment.

  In other words, in this embodiment, the seal mounting groove 12 has an inner surface 123 on the side opposite to the inner space S that forms an inclined surface that collapses so as to narrow the groove width on the groove shoulder 125 side. The side surface 122 rises perpendicularly to the upper end surface 11 a of the side wall 11 of the chamber body 1 and the groove bottom 121.

  Further, the insertion portion 42 in the groove 4 of the spacer 4 has a shape in which the outer side surface 42b can be in close contact with the inner side surface 122 on the inner space S side in the seal mounting groove 12, that is, rises substantially perpendicular to the flange portion 41, The inner side surface 42a facing the seal ring 3 side forms a substantially symmetrical inclined surface with the inner side surface 123 on the opposite side of the inner space S in the seal mounting groove 12, that is, the shoulder portion 43 side extends into the seal mounting groove 12 larger. It is inclined so that it may come out. For this reason, the insertion part 42 in a groove | channel has a shape where thickness increases toward the shoulder part 43 side.

  Therefore, according to the third embodiment, the same operation and effect as those of the first embodiment can be obtained, and when the seal ring 3 is inserted into the seal mounting groove 12 before mounting, The insertion portion 42 can be easily inserted into the seal mounting groove 12 and mounted. Moreover, since the seal mounting groove 12 has a shape in which only one inner side surface 123 is inclined, the cost of groove processing can be reduced as compared with the case where both surfaces are inclined surfaces.

  In each of the above-described embodiments, the seal mounting groove 12 is formed on the upper end surface 11a of the side wall 11 of the chamber body 1. However, in the present invention, even when the seal mounting groove 12 is formed on the lower surface 2a of the lid body 2. Can be implemented as well.

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 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 open state which shows the sealing structure by the 2nd form which concerns on this invention. It is sectional drawing of the open state which shows the sealing structure by the 3rd 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. 6 as a sealing structure by a prior art. It is a figure for demonstrating the problem in the conventional sealing structure shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chamber main body 11 Side wall 12 Seal mounting groove 121 Groove bottom 122,123 Inner side surface 124,125 Groove shoulder 2 Lid body 3 Seal ring 3a, 3b Side surface bulging part 3c Lower part 3d Head part 4 Spacer 41 ridge part 42 Groove insertion part 42a Inner side surface 43 Shoulder S Internal space (sealing target space)

Claims (6)

  A dovetail-shaped seal mounting groove formed on one of the two members facing each other, a side bulging portion is held in the seal mounting groove, and a head projecting from the seal mounting groove is a portion of the two members. A seal ring made of a rubber-like elastic material that can be in close contact with the other, and a spacer made of a material that is held in the seal mounting groove on the sealing target space side of the seal ring and has a rigidity higher than that of the seal ring, A spacer is supported on the groove shoulder on the sealing target space side of the seal mounting groove, and is fitted to the inner side surface of the seal mounting groove on the sealing target space side, and the side bulge portion of the seal ring In the groove that presses against the inner surface of the space to be anti-sealed, and a shoulder between the flange and the groove insert, and the wall thickness of the flange is the non-compressed thickness of the seal ring Seal mounting groove Sealing structures being smaller than the projecting height of al.   The width between the groove shoulders of the seal mounting groove is larger than the width between the side bulging portions of the seal ring, and the width between the shoulder portion of the spacer held in the seal mounting groove and the groove shoulder facing the spacer shoulder groove is the side bulge. The sealing structure according to claim 1, wherein the sealing structure is smaller than a width between the protruding portions.   2. The sealing structure according to claim 1, wherein an inner side surface of the spacer insertion portion in the groove facing the seal ring side is inclined so as to protrude into the seal mounting groove as the shoulder portion side increases.   2. The sealing structure according to claim 1, wherein a fitting surface between the seal mounting groove and the in-groove insertion portion of the spacer rises substantially perpendicular to the opposing surfaces of the two members.   The groove shoulder on the sealing target space side of the seal mounting groove is lower than the groove shoulder on the anti-sealing target space side, and the thickness of the collar portion of the spacer is larger than the difference in height between the both shoulders of the groove. The sealing structure according to claim 1.   The sealing structure according to claim 1, wherein the spacer is made of PTFE.

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