Flange structure and vacuum pumping system using same

Abstract

To provide a flange structure and a vacuum exhaust system using the same that can allow displacement between flanges when pipes are connected using flanges.SOLUTION: A flange structure connecting a first pipe and a second pipe includes a first fixed flange provided at the tip of the first pipe, a second fixed flange provided at the tip of the second pipe, a seal member provided on one of the first fixed flange and the second fixed flange, a movable flange that has a frame shape so as to surround the outer periphery of the second pipe and is movable in a direction intersecting the extending direction of the second pipe on the inner side of the second fixed flange, and a fixing member that fixes the movable flange to the first fixed flange.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to a flange structure and a vacuum exhaust system using the same. [Background technology]

[0002] Conventionally, a method for assembling a vacuum processing apparatus that suppresses damage to a vacuum vessel has been known (for example, see Patent Document 1). In such a method for assembling a vacuum processing apparatus, a bottom flange and a flange member are attached to a reaction tube and an exhaust port, respectively, and the bottom flange and the flange member are fixed to each other by a shaft. Next, the reaction tube is lifted to an upper position and the bottom flange is fixed to a housing, and then the flange member and the exhaust pipe are connected to each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-104755 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a flange structure that can tolerate misalignment between flanges when connecting pipes using flanges, and a vacuum exhaust system using the same. [Means for solving the problem]

[0005] In order to achieve the above object, a flange structure according to one embodiment of the present disclosure is a flange structure for connecting a first pipe and a second pipe, comprising: a first fixing flange provided at a tip of the first pipe; a second fixing flange provided at a tip of the second pipe; a seal member provided on one of the first fixed flange and the second fixed flange; a movable flange having a frame shape surrounding an outer periphery of the second pipe at a rear side of the second fixed flange and movable in a direction intersecting an extension direction of the second pipe; a fixing member for fixing the movable flange to the first fixed flange; death, the second fixed flange and the movable flange have groove structures on opposing surfaces that face the extension direction and can face each other, the opposing surface of the second fixing flange includes a first groove that circumferentially surrounds the second pipe, and a first protrusion that protrudes from a bottom surface of the first groove on an outer side of the first groove, the opposing surface of the movable flange includes a second groove circumferentially extending on the inner side and a second protrusion protruding from a bottom surface of the second groove on the outer side of the second groove, The groove structure is configured such that the first protrusion enters the second groove with a gap therebetween, and the second protrusion enters the first groove with a gap therebetween, thereby movably engaging the movable flange in a direction intersecting the extending direction. . Effect of the Invention

[0006] According to the present disclosure, piping can be connected while allowing for misalignment between flanges. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a cross-sectional view showing a configuration example of a vertical heat treatment apparatus. [Diagram 2] FIG. 2 is a cross-sectional view showing a configuration example of a vertical heat treatment apparatus. [Diagram 3] FIG. 1 illustrates a portion of a vacuum pumping system according to an embodiment of the present disclosure. [Figure 4] FIG. 13 is a diagram showing an example of connecting rectangular pipes together. [Diagram 5] 13 is a diagram showing an example of connecting a centering pipe having a flange structure according to an embodiment of the present disclosure to a normal pipe 863 consisting of a rectangular pipe. FIG. [Figure 6] FIG. 2 is a side view of a flange structure according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a cross-sectional view showing in detail a seal structure according to an embodiment of the present disclosure. [Figure 8] 1 is a diagram illustrating an example of a fastened state of a flange structure according to an embodiment of the present disclosure. FIG. [Figure 9] 13 is a diagram showing a state in which a normal flange and a fastening flange are fixedly connected in a normal position. FIG. [Figure 10] FIG. 13 is a diagram showing an example of a fixed connection in a downward and leftward eccentric state. [Figure 11] FIG. 13 is a diagram showing an example of a fixed connection in an eccentric state upward and to the right. [Figure 12] FIG. 13 is a diagram showing the connection and fixation in a state where the shaft is rotated 1.2 degrees in one direction. [Figure 13] 1A to 1C are diagrams illustrating an example of a manufacturing method for a flange structure according to an embodiment of the present disclosure. [Figure 14] FIG. 1 is a diagram showing a vacuum exhaust system. [Figure 15] 13 is a diagram showing an alignment pipe 862 having a flange structure according to this embodiment at the tip of an exhaust passage. FIG. [Figure 16] 11A and 11B are diagrams for explaining a method of aligning a core-adjusting pipe and a normal pipe. [Figure 17] 13A to 13C are diagrams for explaining a method of fastening a centering piping to a normal piping. [Figure 18] FIG. 13 is a diagram showing the final state of fixing the centering piping and the normal piping. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] [Vertical heat treatment equipment] First, a configuration example of a vertical heat treatment device having a reaction tube unit that can be transported by a transport method according to an embodiment will be described. A vertical heat treatment device with a double-tube structure will be described below, but a vertical heat treatment device with a single-tube structure may also be used. Figures 1 and 2 are cross-sectional views showing a configuration example of a vertical heat treatment device, where Figure 1 shows a vertical cross section and Figure 2 shows a horizontal cross section.

[0010] As shown in FIG. 1, the vertical heat treatment apparatus 1 includes a reaction tube 34 for accommodating semiconductor wafers (hereinafter referred to as "wafers W") which are substrates, a lid 36 for airtightly closing the opening at the lower end of the reaction tube 34, a wafer boat 38 which is a substrate holder that can be accommodated within the reaction tube 34 and holds a number of wafers W at predetermined intervals, a gas supply means 40 for introducing gas into the reaction tube 34, an exhaust means 41 for exhausting gas within the reaction tube 34, and a heating means 42 for heating the wafers W.

[0011] The reaction tube 34 has a cylindrical inner tube 44 with a ceiling whose lower end is open, and a cylindrical outer tube 46 with a ceiling whose lower end is open and covers the outside of the inner tube 44. The inner tube 44 and the outer tube 46 are made of a heat-resistant material such as quartz, and are arranged coaxially to form a double tube structure.

[0012] The ceiling portion 44A of the inner pipe 44 is, for example, flat. A nozzle accommodating portion 48 that accommodates a gas supply pipe is formed on one side of the inner pipe 44 along its longitudinal direction (vertical direction). For example, as shown in Fig. 2, a part of the side wall of the inner pipe 44 protrudes outward to form a convex portion 50, and the inside of the convex portion 50 is formed as the nozzle accommodating portion 48. A rectangular opening 52 having a width L1 is formed on the opposite side wall of the inner pipe 44 facing the nozzle accommodating portion 48 along its longitudinal direction (vertical direction).

[0013] The opening 52 is a gas exhaust port formed so as to exhaust gas from the inner tube 44. The length of the opening 52 is the same as the length of the wafer boat 38, or is formed so as to extend vertically longer than the length of the wafer boat 38. That is, the upper end of the opening 52 is positioned so as to extend to a height equal to or higher than the position corresponding to the upper end of the wafer boat 38, and the lower end of the opening 52 is positioned so as to extend to a height equal to or lower than the position corresponding to the lower end of the wafer boat 38. Specifically, as shown in FIG. 1, the height-direction distance L2 between the upper end of the wafer boat 38 and the upper end of the opening 52 is within a range of about 0 mm to 5 mm. Also, the height-direction distance L3 between the lower end of the wafer boat 38 and the lower end of the opening 52 is within a range of about 0 mm to 350 mm.

[0014] The lower end of the reaction tube 34 is supported by a cylindrical manifold 54 made of, for example, stainless steel. A flange portion 56 is formed at the upper end of the manifold 54, and the lower end of the outer tube 46 is placed on the flange portion 56 to support it. A seal member 58 such as an O-ring is interposed between the flange portion 56 and the lower end of the outer tube 46 to make the inside of the outer tube 46 airtight.

[0015] An annular support 60 is provided on the inner wall of the upper part of the manifold 54, and the lower end of the inner tube 44 is placed on the support 60 to support it. A lid 36 is air-tightly attached to the opening at the lower end of the manifold 54 via a seal member 62 such as an O-ring, so as to air-tightly close the opening at the lower end of the reaction tube 34, i.e., the opening of the manifold 54. The lid 36 is made of, for example, stainless steel.

[0016] A rotating shaft 66 is provided in the center of the lid 36, penetrating through the magnetic fluid seal portion 64. The lower portion of the rotating shaft 66 is rotatably supported by an arm 68A of an elevating means 68 comprising a boat elevator.

[0017] A rotating plate 70 is provided at the upper end of the rotating shaft 66, and the wafer boat 38 holding the wafers W is placed on the rotating plate 70 via a quartz heat retention stand 72. Therefore, by raising and lowering the lifting means 68, the lid 36 and the wafer boat 38 move up and down as a unit, so that the wafer boat 38 can be inserted into and removed from the reaction tube 34.

[0018] The gas supply means 40 is provided in the manifold 54, and introduces gases such as a film forming gas, an etching gas, and a purge gas into the inner tube 44. The gas supply means 40 has a plurality of (e.g., three) quartz gas supply pipes 76, 78, 80. Each of the gas supply pipes 76, 78, 80 is provided in the inner tube 44 along its longitudinal direction, and its base end is bent into an L-shape and supported so as to pass through the manifold 54.

[0019] As shown in FIG. 2, the gas supply pipes 76, 78, 80 are arranged in a row along the circumferential direction in the nozzle accommodating portion 48 of the inner pipe 44. A plurality of gas holes 76A, 78A, 80A are formed in each gas supply pipe 76, 78, 80 at a predetermined interval along the longitudinal direction, and each gas can be discharged from each gas hole 76A, 78A, 80A in the horizontal direction. The predetermined interval is set to be the same as the interval between the wafers W supported by the wafer boat 38, for example. The height direction positions of the gas holes 76A, 78A, 80A are set to be located at the middle between the wafers W adjacent to each other in the vertical direction, so that each gas can be efficiently supplied to the space between the wafers W. As the types of gases, a film forming gas, an etching gas, and a purge gas are used, and each gas can be supplied through each gas supply pipe 76, 78, 80 as necessary while controlling the flow rate of each gas.

[0020] A gas outlet 82 is formed on the side wall of the upper part of the manifold 54 above the support part 60, so that the gas in the inner tube 44 discharged from the opening 52 through a space 84 between the inner tube 44 and the outer tube 46 can be exhausted. An exhaust means 41 is provided at the gas outlet 82. The exhaust means 41 has an exhaust passage 86 connected to the gas outlet 82, and a pressure adjustment valve 88 and a vacuum pump 90 are provided in this order in the exhaust passage 86, so that the inside of the reaction tube 34 can be evacuated.

[0021] A cylindrical heating means is provided on the outer periphery of the outer tube so as to cover the outer tube. The heating means heats the wafer W accommodated in the reaction tube .

[0022] The overall operation of the vertical heat treatment apparatus 1 is controlled by a control means 95 such as a computer. A computer program for controlling the overall operation of the vertical heat treatment apparatus 1 is stored in a storage medium 96. The storage medium 96 may be, for example, a flexible disk, a compact disk, a hard disk, a flash memory, a DVD, or the like.

[0023] [Vacuum exhaust system] FIG. 3 is a diagram showing a part of a vacuum exhaust system according to an embodiment of the present disclosure. As shown in FIG. 3, the reaction tube 34 is placed on the tube cart 120. The tube cart 120 is a transport jig for transporting the reaction tube 34. The reaction tube 34 is provided with a gas outlet 82 at its lower part. The tube cart 120 is moved to the right side of FIG. 3, and the reaction tube 34 is positioned on the lid 36. The boat elevator is raised to lift the reaction tube 34 to a position where the gas outlet 82 and the exhaust passage 86 can be connected. Then, the gas outlet 82 and the exhaust passage 86 are aligned and connected, and the reaction tube 34 is installed above in this state.

[0024] As shown in Fig. 3, the exhaust passage 86 extends upward, then further extends horizontally and is connected to the reaction tube 34. The lower end of the exhaust passage 86 extending upward is connected to a vacuum pump 90 (not shown) via a piping (see Fig. 1 for the vacuum pump 90). The exhaust passage 86 has a rectangular cross-sectional shape. The exhaust passage 86 has a bellows 861 in the middle. A piping connected to the vacuum pump 90 is connected to the tip of the exhaust passage 86.

[0025] Here, when a circular exhaust passage 86 is used, an error in the connection between the pipes can be tolerated at the bellows 861. That is, because the bellows 861 has elasticity, even if the centers of the pipes used in the exhaust passage 86 are slightly misaligned, the bellows 861 can absorb that error. However, in the case of a rectangular cross-sectional shape, the bellows 861 hardly moves up, down, left, or right. Because the bellows 861 has a bellows structure, it expands and contracts in the direction along the exhaust passage 86, but has no elasticity in the direction perpendicular to the exhaust passage 861, and is structured so as to hardly move at all.

[0026] Fig. 4 is a diagram showing an example in which rectangular pipe 86b is connected to rectangular pipe 86a, Fig. 4(a) is a side view, and Fig. 4(b) is a front view.

[0027] As shown in Fig. 4(a), when rectangular pipe 86b is connected to rectangular pipe 86a, they are fastened together using bolts. As shown in Fig. 4(b), in this case, bolt holes 86c of rectangular pipe 86a and rectangular pipe 86b must be aligned with a high degree of accuracy. In other words, only an error that allows fastening with bolts is allowed, so bolt holes 86c of rectangular pipe 86a and rectangular pipe 86b must be aligned with a high degree of accuracy.

[0028] However, in the case of rectangular pipes 86a and 86b, which have rectangular cross-sectional shapes, it is difficult to deform them using bellows 861, so the position cannot be adjusted while attaching rectangular pipe 86b to rectangular pipe 86a, and assembly must be performed with considerable precision.

[0029] Therefore, in this embodiment, a flange structure that allows movement in a direction intersecting with the rectangular pipe 86a, for example, in the vertical direction, is proposed, making it easier to connect the pipes to each other.

[0030] FIG. 5 is a diagram showing an example in which a centering pipe 862 having a flange structure according to an embodiment of the present disclosure is connected to a normal pipe 863 made of a rectangular pipe.

[0031] As shown in FIG. 5, the flange structure according to this embodiment has a normal flange 100 on the normal pipe 863 side, a seal flange 101 on the centering pipe 862 side, and a fastening flange 102.

[0032] The normal flange 100 is provided at the tip of the normal pipe 863. On the other hand, the seal flange 101 is provided at the tip of the centering pipe 862. The fastening flange 102 is provided on the back side of the centering pipe 862.

[0033] Fig. 6 is a side view of a flange structure according to an embodiment of the present disclosure, Fig. 6(b) is a diagram showing a state in which a normal flange 100 faces a seal flange 101 and a fastening flange 102.

[0034] 6(b), the normal flange 100 and the seal flange 101 face each other, and the fastening flange 102 is located closer to the base than the seal flange 101. As shown in FIG. 6(b), the seal flange 101 has a smaller outer shape than the normal flange 100, and the fastening flange 102 has an outer shape that is the same size as the normal flange 100.

[0035] 6(a) is a front view of the seal flange 101 and the fastening flange 102. As described above, the seal flange 101 has a smaller outer shape than the fastening flange 102, and from the front, the seal flange 101 is contained within the fastening flange 102. Note that the seal flange 101 and the fastening flange 102 are provided so as to surround the periphery of the rectangular pipe, that is, the outer periphery of the centering pipe 862, and therefore have a rectangular opening in the center and a frame-like shape.

[0036] 6(c) is a front view of the normal flange 100. The normal flange 100 is also provided at the peripheral end of a rectangular pipe, and therefore has a frame-like shape surrounding a rectangular opening. The normal flange 100 has a seal groove 100a. A seal member such as an O-ring is provided in the seal groove 100a and fixed so as to be in close contact with the seal flange 101, thereby airtightly connecting the pipes together.

[0037] The seal groove 100a is provided at a position facing the seal flange 101 and close to the opening.

[0038] 7 is a cross-sectional view showing in detail the seal structure according to the embodiment of the present disclosure. As shown in FIG. 7, the seal flange 101 has a groove 101a, and the fastening flange 102 also has a groove 102a. The groove 101a of the seal flange 101 and the groove 102a of the fastening flange 102 are engaged with each other, and the flange 102b of the fastening flange 102 is slidable within the groove 101a. The distance that the flange 102b can move within the groove 101a is the movable distance in each direction. The movable distance can be set to any distance depending on the application, but may be set to a moving distance of up, down, left, and right within 10 mm, preferably within 8 mm, for example.

[0039] The surface of the fastening flange 102 facing the normal flange 100 and the surface of the seal flange 101 facing the normal flange 100 are configured to be flush with each other. This makes it possible to prevent rattling due to a step when the normal flange 100 and the fastening flange 102 are fastened and fixed together.

[0040] Furthermore, a seal groove 100a is provided on the surface of the normal flange 100 facing the seal flange 102, and is structured to maintain airtightness with the seal flange 102. A seal member such as an O-ring is disposed in the seal groove 100a.

[0041] 7 shows an example in which the seal groove 100a is provided on the normal flange 100, but it is also possible to provide the seal groove on the seal flange 101. In this case, the surface of the normal flange 100 facing the seal flange 101 is a flat surface. In that case, it is preferable to make the seal flange 101 and the fastening flange 102 thicker to ensure a sufficient thickness.

[0042] The flange structure according to this embodiment may be configured to accommodate not only the sliding movement of the fastening flange 102 but also the angular deviation. As shown in FIG. 7, the fastening flange 102 is not a completely fitted engagement rail, but is configured such that the flange portion 102b is freely movable, so that it can accommodate inclination. That is, even if the seal flange 101 is not parallel to the normal flange 100 and has a slight inclination, the fastening flange 102 can be adapted and fixedly connected to the normal flange 100. The inclination angle may be, for example, up to 2 degrees, up to 1.5 degrees, or up to 1.2 degrees. The adjustable angle range can be freely set according to the application.

[0043] Fig. 8 is a diagram showing an example of a fastening state of the flange structure according to the embodiment of the present disclosure. As shown in Fig. 8, a normal flange 100 and a fastening flange 102 are fastened with bolts. As described in Fig. 7, the fastening flange 102 has a flange portion 102b that is movable within the groove 101a, and therefore the position can be adjusted so that the bolt holes match the bolt holes of the normal flange 100. This allows the rectangular pipes to be appropriately aligned and easily connected to each other without deformation of the bellows 861.

[0044] In addition, in this embodiment, bolt fastening is used for the fixed connection between the fastening flange 102 and the normal flange 100, but other fixing means such as a clamp may be used. For the fixed connection between the fastening flange 102 and the normal flange 100, various fixing connection means may be used depending on the application.

[0045] 9 is a diagram showing a state in which the normal flange 100 and the fastening flange 102 are fixedly connected in the normal position. In the fixed connection in the normal position, the axial core coincides with the center.

[0046] Fig. 10 is a diagram showing an example of fixed connection in an eccentric state downward and leftward. In the following example, the movable range is 4 mm in each direction. In Fig. 10, the seal groove 100a has moved 4 mm downward and leftward within the seal flange 101. Even in this case, the seal groove 100a and the seal flange 101 face each other, and the fastening flange 102 can be moved to fasten the flanges while maintaining airtightness.

[0047] Fig. 11 is a diagram showing an example of fixed connection in an eccentric state upward and to the right. In Fig. 11, the seal groove 100a has moved 4 mm upward and to the right within the seal flange 101. Even in this case, the seal groove 100a and the seal flange 101 face each other, and the fastening flange 102 can be moved to fasten the flanges while maintaining airtightness.

[0048] Fig. 12 is a diagram showing the connection and fixation in a state where the seal flange 102 is rotated 1.2 degrees in one direction. In Fig. 12, the seal groove 100a moves upward due to the upward forward rotation of the seal flange 102, but since the seal groove 100a and the seal flange 101 face each other, the sealed state can be maintained.

[0049] In this way, the seal structure according to this embodiment allows slight misalignment between the seal flange 102 and the seal groove 100a, and is capable of connecting rectangular pipes together while maintaining a sealed state.

[0050] [How to manufacture flange structure] FIG. 13 is a diagram illustrating an example of a manufacturing method of a flange structure according to an embodiment of the present disclosure.

[0051] 13(a) and (b) are diagrams showing an example of a normal flange attachment process. In the normal flange attachment process, a normal flange 100 is welded to a centering pipe 862.

[0052] Fig. 13(b) is a rear view of Fig. 13(a) and has the same structure as the normal flange 100 described above.

[0053] 13(c) and (d) are diagrams showing an example of a fastening flange installation step. As shown in FIG. 13(c), in the fastening flange installation step, the fastening flange 102 is installed around the centering pipe 862.

[0054] 13(d), it is preferable to provide a regulating member 103 at a position on the front end side of the surface of the centering piping 862, which is deeper than the fastening flange 102. The regulating member 103 may be configured, for example, as a protrusion protruding from the surface of the centering piping 862. This makes it possible to regulate the movement of the fastening flange 102 toward the rear side, and to keep the fastening flange 102 close to the seal flange 101.

[0055] The regulating member 103 may be provided around the entire circumference of the centering piping 862, or may be provided only on a part of the centering piping 862, for example, only on the upper and lower surfaces, or only at the center of the upper, lower and both side surfaces. The regulating member 103 may have various configurations as long as it can regulate the movement of the fastening flange 102 toward the back side of the centering piping 862.

[0056] 13(c) is a diagram showing an example of a seal flange attachment step in which a seal flange 101 is welded to the tip of the centering pipe 862.

[0057] 13(e) and (f) are diagrams showing an example of a seal flange attachment process. As shown in FIG. 13(e), in the seal flange attachment process, the seal flange 101 is welded to the tip of the centering pipe 862. As a result, the fastening flange 102 is confined between the seal flange 101 and the regulating member 103. The seal flange 101 is configured to have a size that allows it to face the seal groove 100a of the normal flange 100 and to maintain its facing relationship with the seal groove 100a even if it moves slightly up and down and left and right.

[0058] FIG. 13( f ) is a front view of FIG. 13( e ), in which the fastening flange 102 surrounds the periphery of the seal flange 101 .

[0059] In addition, the fastening flange 102 is provided with bolt holes 102c corresponding to bolt fastening as required.

[0060] [How to assemble the vacuum exhaust system] Fig. 14 is a diagram showing a vacuum exhaust system. As shown in Fig. 14, a bellows 861 is provided in the middle of an exhaust passage 86. A bellows 861 is also provided at the tip of the exhaust passage 86.

[0061] 15 is a diagram showing an alignment pipe 862 having a flange structure according to this embodiment at the tip of the exhaust passage 86. By using the alignment pipe 862 that can be aligned in this manner, piping connection can be made easier.

[0062] Fig. 16 is a diagram for explaining a method for aligning the centering piping 862 and the normal piping 863. When connecting the normal piping 863 to the centering piping 862, as shown in Fig. 16, a seal flange 101 is aligned with a normal flange 100 provided at the tip of the normal piping 863.

[0063] 17 is a diagram for explaining a method of fastening the centering pipe 862 to the normal pipe 863. As shown in FIG. 17, after the seal flange 101 is aligned with the normal flange 100, the position of the fastening flange 102 is aligned with the normal flange 100.

[0064] Fig. 18 is a diagram showing the final state of fixation. As shown in Fig. 18, after the fastening flange 102 is fitted to the normal flange 100, the two are fastened and fixed by bolts 110. At this time, the seal flange 101 is no longer visible from the outside.

[0065] Note that the normal flange 100 and the fastening flange 102 may be fixedly connected to each other using connecting and fastening means other than the bolts 110 .

[0066] In this way, with the flange structure and vacuum exhaust system of this embodiment, even when rectangular piping is used, misalignment in the direction intersecting the piping when connected is tolerated, making it easy to connect rectangular pipes to each other.

[0067] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. [Explanation of symbols]

[0068] 34 Reaction tube 44 Inner tube 46 Outer tube 76, 78, 80 Gas supply pipes 86 Exhaust passage 100 Normal flange 100a Seal groove 101 Seal flange 102 Fastening flange 110 Volts 861 Bellows 862 Aligning piping 863 Normal piping

Claims

1. A flange structure for connecting a first pipe and a second pipe, a first fixing flange provided at a tip of the first pipe; a second fixing flange provided at a tip of the second pipe; a seal member provided on one of the first fixed flange and the second fixed flange; a movable flange having a frame shape surrounding an outer periphery of the second pipe and disposed on a rear side of the second fixed flange and movable in a direction intersecting an extension direction of the second pipe; a fixing member that fixes the movable flange to the first fixed flange, the second fixed flange and the movable flange have groove structures on opposing surfaces that face the extension direction and can face each other, the opposing surface of the second fixing flange includes a first groove that circumferentially surrounds the second pipe, and a first protrusion that protrudes from a bottom surface of the first groove on an outer side of the first groove, the opposing surface of the movable flange includes a second groove circumferentially extending on an inner side thereof, and a second protrusion protruding from a bottom surface of the second groove on an outer side thereof, The groove structure is a flange structure in which the first convex portion enters the second groove with a gap, and the second convex portion enters the first groove with a gap, thereby movably engaging the movable flange in a direction intersecting the extension direction.

2. The flange structure according to claim 1 , wherein a direction intersecting with an extension direction of the second pipe is a direction perpendicular to z of the second pipe.

3. The flange structure according to claim 1, wherein the first pipe, the second pipe, the first fixed flange, the second fixed flange and the movable flange have a rectangular outer shape in a direction perpendicular to the extension direction of the first pipe and the second pipe.

4. The flange structure according to claim 3 , wherein said quadrilateral is a rectangle.

5. 5. The flange structure according to claim 1, wherein the seal member is disposed in a groove provided in a tip plane of the first fixed flange.

6. 6. A flange structure according to claim 1, wherein the amount of movement of the movable flange in a direction perpendicular to the extension direction of the second pipe is an allowable amount of misalignment between the first fixed flange and the movable flange.

7. The flange structure according to any one of claims 1 to 6, wherein the second fixing flange has an outer shape smaller than that of the first fixing flange.

8. The flange structure according to any one of claims 1 to 7, wherein the movable flange has an outer size larger than that of the second fixed flange.

9. 9. The flange structure according to claim 1, wherein the movable flange has the same outer shape as the first fixed flange.

10. The flange structure according to any one of claims 1 to 9, wherein the fixing member is a screw.

11. The flange structure according to any one of claims 1 to 10, wherein a movement restricting member is provided on an outer surface of the second pipe to restrict movement of the movable flange along the extension direction of the second pipe.

12. The flange structure according to claim 11 , wherein the movement restricting member is a protrusion protruding from an outer surface of the second pipe.

13. The first pipe; The second pipe; The flange structure according to any one of claims 1 to 12, which connects the first pipe and the second pipe; a vacuum exhaust device connected to one of the first pipe and the second pipe.

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