Gate and slit valve

Abstract

A gate (28) comprises: a gate body (42) integrally formed from a metal material; a shaft attachment hole (60) which is positioned at the center of the gate body (42) in a width direction and to which a shaft (38) is attached; a slit hole (58) formed between the shaft attachment hole (60) and a seal surface (46) and extending in the width direction; and a rear surface (56) constituting a rear part of the gate body (42) in a front–rear direction.

Description

Gate and Slit Valves

[0001] The present disclosure relates to gate and slit valves.

[0002] Slit valves are installed in the partitions between sealed chambers used in semiconductor manufacturing equipment and the like. These partitions have wide openings for inserting and removing wafers (semiconductor substrates). Slit valves include a gate and a cylinder (drive mechanism). The drive mechanism opens and closes the opening by displacing the gate vertically via a shaft. The drive mechanism also performs a clamping action to press the gate against the opening in the partition, airtightly closing the opening.

[0003] For example, JP 2023-73982 A describes a gate of a slit valve. SMC Corporation's "Parallel Seal Slit Valve" catalog (URL: https: / / www.smcworld.com / catalog / New-products / mpv / s140-9-xgtp / data / s140-9-xgtp.pdf, accessed August 29, 2024) also describes gates and slit valves.

[0004] Slit valves used in semiconductor manufacturing equipment are required to generate less dust to improve the yield of semiconductor devices. Furthermore, the gates used in slit valves are consumables that require replacement due to wear of the sealing material. To reduce the time-consuming and costly gate replacement work, there is a need to extend the life of the gates in slit valves.

[0005] To meet these requirements, it is desirable to reduce the pressure load applied to the gate during clamping operation in slit valves. Reducing the pressure load on the gate suppresses wear and deterioration of the gate seal material, reduces dust generation, and extends the gate's lifespan.

[0006] However, in conventional slit valves, there are areas where the pressing pressure is low due to bending of the gate, etc. To prevent gas leakage from such areas where the pressing pressure is low, conventional slit valves apply a higher pressing load to the entire gate.

[0007] The present disclosure aims to solve the above-mentioned problems.

[0008] A first aspect of the present disclosure is a gate of a slit valve that opens and closes a wide opening that is short in the vertical direction and long in the width direction, the gate comprising: a wide, plate-shaped gate body that is integrally formed from a metal material and whose dimension in the vertical direction is smaller than its dimension in the width direction; and a seal member attached to the gate body, wherein the gate body has a seal surface that is formed at a front portion of the gate body and has a flat surface perpendicular to a front-rear direction that is perpendicular to the vertical direction and the width direction; and a flat upper end surface that is located at an upper end of the gate body and intersects with the seal surface. a shaft mounting portion located at the center of the gate body in the width direction, extending in the vertical direction, and having a shaft mounting hole to which a shaft is attached; a slit hole formed in the gate body between the shaft mounting hole and the seal surface, penetrating from the upper end surface to the lower end surface in the vertical direction and extending parallel to the seal surface over a predetermined range in the width direction; and a rear surface that forms the rear of the gate body in the front-to-rear direction.

[0009] A second aspect of the present disclosure is a slit valve comprising a gate according to the first aspect, a shaft attached to the shaft mounting hole, and a drive mechanism that drives the shaft to displace the gate in the up-and-down direction and to perform a clamping operation that displaces the gate in the back-and-forth direction.

[0010] According to the present disclosure, the pressing pressure of the gate can be made uniform, thereby reducing the pressing load of the gate, thereby reducing dust generation from the slit valve and reducing the frequency of gate replacement.

[0011] The above objects, features and advantages will be easily understood from the following description of the embodiments, which will be described with reference to the accompanying drawings.

[0012] FIG. 1 is an explanatory diagram showing an example of a semiconductor manufacturing apparatus and an example of a slit valve arrangement. FIG. 2A is a perspective view of a slit valve according to a first embodiment, and FIG. 2B is a perspective view showing the drive mechanism and gate of the slit valve of FIG. 2A in an exploded state. FIG. 3A is a cross-sectional view taken along line IIIA-IIIA in FIG. 2A, and FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 2A. FIG. 4A is a perspective view of a gate according to the first embodiment, and FIG. 4B is a perspective view of the rear side of the gate of FIG. 4A. FIG. 5A is a cross-sectional view taken along line VA-VA in FIG. 4A, and FIG. 5B is a cross-sectional view taken along line VB-VB in FIG. 4A. FIG. 6A is a diagram showing the distribution of pressing load when the seal surface of the gate of the first embodiment is pressed against the body, as viewed from the top-bottom direction, and FIG. 6B is a diagram showing the distribution of pressing load on the seal surface of FIG. 6A, as viewed from the front-rear direction. FIG. 7A is a cross-sectional view of a gate according to a comparative example taken along a cross section perpendicular to the up-down direction, and FIG. 7B is a diagram showing the distribution of pressing load when the seal surface of the gate according to the comparative example is pressed against the body.

[0013] 1 includes a load lock chamber 12, a transfer chamber 14, and multiple process chambers 16. The transfer chamber 14 incorporates a transfer device 18 that transfers wafers (semiconductor substrates), and is connected to the multiple process chambers 16 and the load lock chamber 12. Slit valves 20 are provided in partitions 22 between the load lock chamber 12 and the transfer chamber 14, and in partitions 22 between the transfer chamber 14 and the process chambers 16.

[0014] A body 24 of the slit valve 20 is attached to these partition sections 22. The slit valve 20 airtightly separates the partition sections 22 via the body 24 so that they can be opened and closed. The body 24 has an opening 26 for passing a thin wafer through. The opening 26 is formed to be long in the horizontal width direction and short and wide in the vertical direction to match the shape of the wafer. The slit valve 20 opens and closes the opening 26 by displacing an internal gate 28 (see FIGS. 2A and 2B ).

[0015] The application location of slit valve 20 is not limited to semiconductor manufacturing apparatus 10 shown in FIG. 1 , and may be provided, for example, in partition portion 22 between an exposure tool (not shown) and load lock chamber 12. In addition, although the present embodiment describes an example in which slit valve 20 includes body 24 having opening 26, the present invention is not limited to this. Opening 26 may also be provided in the housing of semiconductor manufacturing apparatus 10 itself. In such a case, a slit valve 20 without body 24 may be used.

[0016] In this specification, the terms width direction, up-down direction, and front-rear direction are used to indicate the shapes of components and the relative positions of the components. The width direction is a horizontal direction and is the same direction as the longitudinal direction of the opening 26. One of the width directions is called the first direction, and the other opposite to the first direction is called the second direction. The up-down direction is the vertical direction (vertical direction). The front-rear direction is a horizontal direction that is perpendicular to the width direction and the up-down direction. In the front-rear direction, the pressing direction in the clamping operation of the slit valve 20 is called the front or forward direction, and the opposite direction is called the rear or rearward direction. These terms are used to describe the shapes of components belonging to the slit valve 20 and the relative positions of the components, but do not limit the orientation of the slit valve 20.

[0017] As shown in Figures 2A and 2B, the slit valve 20 of this embodiment includes a body 24, a gate 28, and a drive mechanism 30. The body 24 has a rectangular parallelepiped shape that is elongated in the width direction. As shown in Figures 3A and 3B, a gate accommodating chamber 32 that accommodates the gate 28 is formed inside the body 24. The body 24 also has an opening 26. The opening 26 includes a first opening 26A provided in a front wall 34 facing forward and a second opening 26B provided in a rear wall 36 facing rearward. As shown in Figure 2A, the first opening 26A has a wide shape that is short in the up-down direction and large in the width direction when viewed from the front-to-rear direction.

[0018] 3A and 3B , the first opening 26A in the front wall 34 penetrates the front wall 34 in the front-rear direction and communicates with the gate accommodating chamber 32 inside the body 24. The second opening 26B in the rear wall 36 penetrates the rear wall 36 in the front-rear direction and communicates with the gate accommodating chamber 32. The center positions of the first opening 26A in the front wall 34 and the second opening 26B in the rear wall 36 are the same in the width direction and the up-down direction. That is, the second opening 26B overlaps with the first opening 26A and has the same shape. The shape of the second opening 26B may differ from that of the first opening 26A within the range through which a wafer can pass, and the second opening 26B may have dimensions larger in the width direction and the up-down direction than the first opening 26A.

[0019] 3A and 3B , the gate accommodating chamber 32 extends vertically inside the body 24. The lower end of the gate accommodating chamber 32 is closed by the drive mechanism 30. The gate accommodating chamber 32 accommodates the gate 28 and the shaft 38 so that they can be displaced in the vertical and front-rear directions. Therefore, the vertical, width, and front-rear dimensions of the gate accommodating chamber 32 are greater than the vertical, width, and front-rear dimensions of the gate 28.

[0020] As shown in FIG. 2A , the drive mechanism 30 is attached to the lower part of the body 24. The drive mechanism 30 has a plate-shaped body attachment portion 40 at its upper end. The body attachment portion 40 airtightly closes the lower end of the gate accommodating chamber 32. An air cylinder, an actuator, and the like are built into the drive mechanism 30. As shown in FIG. 2B , a shaft 38 protrudes from the upper end of the drive mechanism 30. The shaft 38 protrudes upward through a shaft insertion hole 41 in the body attachment portion 40.

[0021] The shaft 38 supports the gate 28 and transmits the driving force generated by the drive mechanism 30 to the gate 28. A bellows (not shown) is attached around the shaft 38. The bellows is joined to the body mounting portion 40 and the shaft 38, and airtightly separates the gate housing chamber 32 from the interior of the drive mechanism 30.

[0022] As shown in Figures 3A and 3B, the gate 28 is attached to and supported by a shaft 38. The gate 28 includes a gate body 42 and a seal member 44. As shown in Figure 2B, the gate body 42 is made of a metal material and is formed in a wide plate shape with a width dimension greater than a vertical dimension and a front-to-rear dimension smaller than the vertical and width dimensions. The gate 28 is formed in a generally rectangular shape with rounded corners when viewed from the front-to-rear direction.

[0023] As shown in FIGS. 4A and 4B , the gate body 42 has a sealing surface 46, an upper end surface 48, a lower end surface 50, a first side end 52, a second side end 54, a rear surface 56, a slit hole 58, a shaft mounting hole 60, and a fastening hole 62. The sealing surface 46 is located at the front of the gate body 42 and is a generally rectangular flat surface that appears when viewed from the front of the gate body 42 in the front-to-rear direction and is formed perpendicular to the front-to-rear direction. The width and vertical dimensions of the sealing surface 46 are greater than the width and vertical dimensions of the first opening 26A formed in the body 24 shown in FIG. 2A . As shown in FIG. 4A , a sealing groove 64 is formed around the periphery of the sealing surface 46, extending annularly along the outer periphery of the sealing surface 46. As shown in FIG. 5A , a sealing member 44 is fitted into the sealing groove 64.

[0024] 3B , the sealing surface 46 is a surface that is pressed against the front wall 34 of the body 24 by the drive mechanism 30. When the sealing surface 46 is pressed against the front wall 34, the sealing member 44 airtightly closes the gap between the sealing surface 46 and the first opening 26A (front wall 34).

[0025] As shown in Figure 4A, the upper end surface 48 is located at the upper end of the gate body 42. The upper end surface 48 is a flat surface. The upper end surface 48 is vertical and perpendicular to the sealing surface 46 and the rear surface 56. A slit hole 58 and a fastening hole 62 open in the upper end surface 48.

[0026] 4B , the lower end surface 50 is located at the lower end of the gate body 42. The lower end surface 50 is a flat surface. The lower end surface 50 is vertical and perpendicular to the seal surface 46 and the rear surface 56. A slit hole 58 and a shaft mounting hole 60 open in the lower end surface 50.

[0027] 4A and 4B , the first side end 52 is located at the side end in the first width direction of the gate body 42. The first side end 52 has a flat surface that extends in the vertical direction and is perpendicular to the sealing surface 46. The upper end of the first side end 52 is connected to the upper end surface 48 via a curved first chamfered portion 66A. The lower end of the first side end 52 is connected to the lower end surface 50 via a curved second chamfered portion 66B. The first side end 52 intersects with a first inclined surface 74 of the rear surface 56.

[0028] The second side end 54 is located at the side end in the second width direction of the gate body 42. The second side end 54 has a flat surface that extends in the vertical direction and is perpendicular to the seal surface 46. The upper end of the second side end 54 is connected to the upper end surface 48 via a curved third chamfered portion 66C, and the lower end of the second side end 54 is connected to the lower end surface 50 via a curved fourth chamfered portion 66D. The second side end 54 intersects with the second inclined surface 76 of the rear surface 56.

[0029] As shown in Figure 4B, the rear surface 56 has a rear bulge 68, a first rear end surface 70, a second rear end surface 72, a first inclined surface 74, and a second inclined surface 76. The rear bulge 68 is located in the center in the width direction and is the portion of the gate 28 that bulges most rearward. The rear bulge 68 extends in the up-down direction while maintaining a constant dimension in the width direction. The rear bulge 68 forms part of the shaft mounting portion 78. A shaft mounting hole 60 is formed inside the rear bulge 68.

[0030] The first rear end surface 70 extends in the first direction from a side portion in the first direction of the rear bulge portion 68. The first rear end surface 70 is formed by a flat surface parallel to the sealing surface 46. The first rear end surface 70 is connected to the rear bulge portion 68 via an inclined first step portion 80. A first end portion 82 in the first direction of the first rear end surface 70 is connected to the first inclined surface 74.

[0031] The first inclined surface 74 is formed between the first end 82 and the first side end 52. The first inclined surface 74 is parallel to the up-down direction and inclined with respect to the front-rear direction and the width direction. The first inclined surface 74 inclines so as to approach the sealing surface 46 as it approaches the first side end 52 along the first width direction. The portion where the first inclined surface 74 is formed is also referred to as a first tapered portion 84.

[0032] The second rear end surface 72 extends in the second direction from a side portion of the rear bulge portion 68 in the second direction. The second rear end surface 72 is formed by a flat surface parallel to the sealing surface 46. The second rear end surface 72 is connected to the rear bulge portion 68 via an inclined second step portion 86. A second end portion 88 of the second rear end surface 72 in the second direction is connected to the second inclined surface 76. The length in the width direction of the second rear end surface 72 is equal to the length in the width direction of the first rear end surface 70.

[0033] The second inclined surface 76 is formed between the second end 88 and the second side end 54. The second inclined surface 76 is parallel to the up-down direction and inclined with respect to the front-rear direction and the width direction. The second inclined surface 76 inclines so as to approach the sealing surface 46 as it approaches the second side end 54 along the second width direction. The portion where the second inclined surface 76 is formed is also referred to as a second tapered portion 90.

[0034] The shaft mounting hole 60 is formed in the center of the gate body 42 in the width direction, closer to the rear surface 56 in the front-to-rear direction. The shaft mounting hole 60 opens to the lower end surface 50 and extends upward from the lower end surface 50. The shaft mounting hole 60 is long in the width direction and short in the front-to-rear direction. A rear portion of the shaft mounting hole 60 is located rearward of the first rear end surface 70 and the second rear end surface 72. The shaft 38 extending from the drive mechanism 30 is inserted into the shaft mounting hole 60. Note that the shape of the shaft mounting hole 60 is not limited to the example shown in the figure and can be appropriately changed depending on the shape of the shaft 38, such as to be cylindrical, for example.

[0035] As shown in FIG. 5B , the upper end of the shaft mounting hole 60 is covered by an upper end wall 92. The upper end wall 92 prevents the shaft 38 from moving upward and prevents the gate body 42 from shifting in the vertical direction relative to the shaft 38. The upper end wall 92 is formed flush with the upper end surface 48. As shown in FIG. 3B , the upper end wall 92 is formed with fastening holes 62 that penetrate the upper end wall 92 in the vertical direction and through which fastening members 94, such as bolts or screws, are inserted. The fastening members 94 are threadedly engaged with the threaded structure at the upper end of the shaft 38 through the fastening holes 62 to secure the gate body 42 to the shaft 38. The shaft mounting portion 78 includes the shaft mounting hole 60, the upper end wall 92, the fastening holes 62, and the rearward bulge 68.

[0036] The shaft mounting portion 78 is not limited to the above configuration. For example, the upper end wall 92 may not be formed, and the shaft mounting hole 60 may penetrate in the vertical direction. In this case, the fastening hole 62 may be formed so as to extend in the front-rear direction through the rear bulge portion 68 and open to the rear surface 56. With this type of shaft mounting portion 78, the shaft 38 is fixed from the rear of the gate body 42.

[0037] As shown in FIGS. 4A , 4B , and 5A , the slit 58 penetrates vertically from the upper end surface 48 to the lower end surface 50 and extends across a predetermined range in the width direction while maintaining a constant width in the front-rear direction. In this embodiment, the position of the first edge 96, which is the edge of the slit 58 in the first direction, may coincide with or may differ from the position of the first end 82 of the first rear end surface 70. The slit 58 is formed symmetrically with respect to the center in the width direction. The width length of the slit 58 may be, for example, approximately 50% of the width length of the gate body 42. If the width length of the slit 58 is too long, the pressing load will be concentrated at the first side end 52 and the second side end 54, reducing the pressing load in the width center portion and increasing the variation in the pressing load on the sealing surface 46. Furthermore, if the width of the slit hole 58 is too short, the first side end portion 52 and the second side end portion 54 will be more likely to deform rearward, reducing the pressing load at these areas and increasing the variation in the pressing load.

[0038] The slit 58 is located between the shaft mounting hole 60 and the seal surface 46 in the front-to-rear direction, and is positioned closer to the shaft mounting hole 60 than the midpoint between them. The slit 58 separates the gate body 42 into an abutment portion 100 on the seal surface 46 side and an arm portion 102 on the rear surface 56 side.

[0039] The contact portion 100 is separated from the shaft mounting portion 78 via the slit hole 58. Therefore, the pressing load from the shaft 38 is applied to the contact portion 100 from two locations separated in the width direction via the arm portion 102. The dimension of the slit hole 58 in the front-rear direction is set to a dimension that prevents the arm portion 102 from coming into contact with the contact portion 100 even when a pressing load is applied from the shaft 38.

[0040] 5A , the slit 58 extends in the width direction while maintaining a constant distance in the front-rear direction from the seal surface 46. The thickness T1 in the front-rear direction of the abutment portion 100 from the seal surface 46 to the slit 58 is smaller than the thickness T2 in the front-rear direction from the slit 58 to the first rear end surface 70 and the second rear end surface 72. Therefore, the abutment portion 100 is more likely to bend than the arm portion 102 when subjected to a load in the front-rear direction.

[0041] The first tapered portion 84 extends in a first direction from the arm portion 102. The dimension (thickness) of the first tapered portion 84 in the front-rear direction varies depending on the position in the width direction. The dimension of the first tapered portion 84 in the front-rear direction is greatest at the connection portion with the arm portion 102 and gradually decreases toward the first side end 52. The dimension of the first tapered portion 84 in the front-rear direction at the first side end 52 is approximately equal to the thickness T1 of the abutting portion 100 in the front-rear direction.

[0042] The second tapered portion 90 extends in the second direction from the arm portion 102. The second tapered portion 90 is formed symmetrically with the first tapered portion 84 about the center in the width direction, and its longitudinal dimension decreases as it progresses in the second direction, similar to the first tapered portion 84. The longitudinal dimension of the second tapered portion 90 at the second side end 54 is approximately equal to the longitudinal thickness T1 of the abutting portion 100.

[0043] Such first tapered portion 84 and second tapered portion 90 suppress the influence on distribution of the pressing load while enabling a reduction in weight of the gate body 42. Note that if weight reduction is not required, the first tapered portion 84 and second tapered portion 90 do not have to be provided.

[0044] As shown in FIG. 5A , a seal member 44 is attached to the seal surface 46 of the gate body 42. The seal member 44 is formed in an annular shape from an elastic material such as rubber or elastomer. The seal member 44 is held in the seal groove 64 while protruding forward from the seal surface 46. When the gate 28 is pressed against the front wall of the gate accommodating chamber 32 by the clamping operation, the seal member 44 comes into close contact with the front wall of the gate accommodating chamber 32, airtightly closing the gap between the body 24 and the seal surface 46, as shown in FIGS. 3A and 3B .

[0045] The gate 28 and slit valve 20 of this embodiment are configured as described above. The gate 28 is moved up and down by the shaft 38 in the slit valve 20. When the shaft 38 is displaced downward by the drive mechanism 30, the gate 28 retreats downward from the opening 26, and the first opening 26A in the front wall 34 and the second opening 26B in the rear wall 36 become open.

[0046] 3B , the slit valve 20 causes the drive mechanism 30 to raise the shaft 38, displacing the gate 28 to the upper end position. The slit valve 20 then causes the shaft 38 to displace the gate 28 from the upper end position forward, performing a clamping operation to press the gate 28 against the front wall 34. The clamping operation applies a forward pressing load to the gate 28.

[0047] 6A and 6B show the results of calculations of the distribution of deformation in the front-to-rear direction of each part when a pressing load is applied from the shaft 38 to the gate 28 in FIG. 4A. Using the position of the shaft mounting hole 60 as a reference, the greater the amount of displacement in the front-to-rear direction relative to the shaft mounting hole 60, the whiter the part. In other words, the whiter the part, the greater the amount of rearward deformation, indicating a location that is more likely to deform in a way that releases the load. In other words, the whiter the part, the smaller the pressing load. Furthermore, the closer the color is to black, the smaller the amount of deformation, indicating that a larger pressing load is applied.

[0048] As shown in the figure, the displacement distribution of the gate 28 of this embodiment exhibits high uniformity in the vertical direction on the sealing surface 46, but relatively large variation in the width direction. The first side end 52, the second side end 54, and the widthwise center of the sealing surface 46 are areas where the displacement is relatively large and the pressing load is small. Although there are areas where the displacement is relatively small and the pressing load is relatively small (areas where the pressing load is large) near the ends of the slit hole 58, the shading difference across the sealing surface 46 is reduced compared to the comparative example ( FIG. 7B ) described below. As shown in the figure, by making the thickness T1 of the abutment portion 100 thinner than the thickness T2 of the arm portion 102, the displacement at the widthwise center is approximately the same as the displacement at the first side end 52 and the second side end 54, thereby suppressing the concentration of the pressing load at the widthwise center. Therefore, with the gate 28 of this embodiment, it can be confirmed that the pressing load is relatively uniform across the sealing surface 46.

[0049] 7A shows a gate 280 according to a comparative example (SMC Corporation, "Parallel Seal Slit Valve" catalog, URL: https: / / www.smcworld.com / catalog / New-products / mpv / s140-9-xgtp / data / s140-9-xgtp.pdf, retrieved August 29, 2024). This gate 280 differs from the gate 28 of the present embodiment shown in FIGS. 4A and 4B in that it does not have a slit hole 58, and does not have a first inclined surface 74 (first tapered portion 84) or a second inclined surface 76 (second tapered portion 90).

[0050] 7B shows the calculated displacement of each portion of the gate 280 when the same pressure load as in FIG. 6A is applied to the gate 280 of the comparative example. As shown in FIG. 7B, the gate 280 of the comparative example has the smallest displacement and the strongest pressure load near the shaft 38. As a result, the variation in the pressure load on the seal surface 46 is greater than that of the gate 28 of the embodiment. In the gate 280 of the comparative example, the pressure load is concentrated in the center in the width direction. Furthermore, wear of the seal member 44 and dust generation are greater in the center in the width direction.

[0051] 6A and 6B , the gate 28 of this embodiment reduces the variation in the pressure load on the seal surface 46, making it possible to prevent gas leakage even with a smaller pressure load. As a result, the gate 28 and slit valve 20 of this embodiment can suppress deterioration and dust generation due to wear of the seal member 44.

[0052] The following additional notes are further disclosed regarding the above embodiment.

[0053] (Note 1) A gate (28) of the present disclosure is a gate of a slit valve (20) that opens and closes a wide opening (26) that is short in the vertical direction and long in the width direction, and includes a wide, plate-like gate body (42) that is integrally formed from a metal material and whose dimension in the vertical direction is smaller than its dimension in the width direction, and a seal member (44) attached to the gate body, and the gate body has a seal surface (46) that is formed at the front of the gate body and has a flat surface perpendicular to the vertical direction and the front-rear direction that is perpendicular to the width direction, and a flat upper end surface that is located at the upper end of the gate body and intersects with the seal surface (48), a flat lower end surface (50) located at the lower end of the gate body and intersecting the seal surface, a shaft mounting portion (78) located at the center of the width direction of the gate body and extending in the vertical direction, having a shaft mounting hole (60) to which a shaft (38) is attached, a slit hole (58) formed in the gate body between the shaft mounting hole and the seal surface, penetrating from the upper end surface to the lower end surface in the vertical direction and extending parallel to the seal surface over a predetermined range in the width direction, and a rear surface (56) that forms the rear of the gate body in the front-to-rear direction.

[0054] According to the above configuration, the variation in the pressing load on the sealing surface is suppressed, so that the gate can be airtightly closed with a smaller load, thereby suppressing wear on the sealing member and achieving low dust generation and a long life.

[0055] In the gate according to Supplementary Note 1, the rear surface may include a first flat rear end surface (70) extending parallel to the seal surface from the shaft mounting portion in a first direction in the width direction, a first inclined surface (74) extending from a first end (82) of the first rear end surface in the first direction toward a first side end (52) of the gate body in the first direction and at an angle to approach the seal surface, a second flat rear end surface (72) extending parallel to the seal surface from the shaft mounting portion in a second direction opposite to the first direction in the width direction, and a second inclined surface (76) extending from a second end (88) of the second rear end surface in the second direction toward a second side end (54) of the gate body in the second direction and at an angle to approach the seal surface. This configuration enables the weight of the gate to be reduced while suppressing variations in the pressing load on the seal surface.

[0056] (Appendix 3) In the gate described in Appendix 2, the widthwise position of the end of the slit hole in the first direction may be the same as the widthwise position of the first end of the first rear end surface, and the widthwise position of the end of the slit hole in the second direction may be the same as the widthwise position of the second end of the second rear end surface.

[0057] (Appendix 4) In the gate described in Appendix 2 or 3, the thickness of the gate body in the front-to-rear direction at the first side end and the second side end may be the same as the thickness of the portion between the slit hole and the sealing surface in the front-to-rear direction.

[0058] (Supplementary Note 5) In the gate according to any one of Supplementary Notes 2 to 4, the shaft attachment portion may bulge rearward in the front-to-rear direction relative to the first rear end surface and the second rear end surface. With this configuration, the thickness of the gate in the front-to-rear direction is reduced, thereby reducing the weight of the gate.

[0059] (Supplementary Note 6) In the gate according to Supplementary Note 1 or 2, the thickness (T1) of the gate body in the front-rear direction at the contact portion between the slit hole and the seal surface may be thinner than the thickness (T2) of the arm portion between the slit hole and the rear surface in the front-rear direction. With this configuration, concentration of the pressing load on the seal surface at the center in the width direction can be suppressed, and variation in the pressing load on the seal surface can be suppressed.

[0060] (Supplementary Note 7) In the gate according to any one of Supplementary Notes 1 to 5, the length of the slit in the width direction may be equal to or greater than half of the length of the gate body in the width direction. With this configuration, a decrease in the pressing load at the first side end and the second side end is suppressed.

[0061] (Supplementary Note 8) In the gate according to any one of Supplementary Notes 1 to 7, the shaft mounting portion may have an upper end wall (92) that extends flush with the upper end surface and closes the upper end of the shaft mounting hole, and a fastening hole (62) that penetrates the upper end wall in the vertical direction and through which a fastening member (94) that fastens the shaft is inserted. With this configuration, the gate can be attached and detached simply by operating it from above the body, making gate replacement work easier.

[0062] (Supplementary Note 9) A slit valve according to the present disclosure includes the gate according to any one of Supplementary Notes 1 to 8, the shaft attached to the shaft attachment hole, and a drive mechanism (30) that performs an opening / closing operation to displace the shaft in the up-and-down direction and a clamping operation to displace the shaft in the back-and-forth direction. This configuration reduces dust generation from the slit valve and reduces the frequency of gate replacement.

[0063] (Supplementary Note 10) The slit valve according to Supplementary Note 9 may further include a body (24) that houses the gate and has the opening that is opened and closed by the gate.

[0064] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

Claims

1. A gate (28) of a slit valve (20) that opens and closes a wide opening (26) that is short in the vertical direction and long in the width direction, comprising: a wide, plate-shaped gate body (42) that is integrally formed from a metal material and whose vertical dimension is smaller than its width dimension; and a seal member (44) attached to the gate body, wherein the gate body comprises: a seal surface (46) formed at the front of the gate body and having a flat surface perpendicular to the vertical direction and the front-to-rear direction that is perpendicular to the width direction; a flat upper end surface (48) located at the upper end of the gate body and intersecting with the seal surface; a flat lower end surface (50) located at the lower end of the gate body and intersecting with the seal surface; a shaft attachment portion (78) located at the center of the width direction of the gate body, extending in the vertical direction, and having a shaft attachment hole (60) to which a shaft (38) is attached; a slit hole (58) formed in the gate body between the shaft mounting hole and the seal surface, penetrating from the upper end surface to the lower end surface in the vertical direction and extending parallel to the seal surface over a predetermined range in the width direction; and a rear surface (56) that forms the rear of the gate body in the front-to-rear direction.

2. A gate according to claim 1, wherein the rear surface has: a flat first rear end surface (70) extending from the shaft mounting portion in a first direction in the width direction and parallel to the seal surface; a first inclined surface (74) extending from a first end (82) in the first direction of the first rear end surface toward a first side end (52) of the gate body in the first direction and at an angle so as to approach the seal surface; a flat second rear end surface (72) extending from the shaft mounting portion in a second direction opposite to the first direction in the width direction and parallel to the seal surface; and a second inclined surface (76) extending from a second end (88) in the second direction of the second rear end surface toward a second side end (54) of the gate body in the second direction and at an angle so as to approach the seal surface.

3. A gate as described in claim 2, wherein the widthwise position of the end of the slit hole in the first direction is the same as the widthwise position of the first end of the first rear end surface, and the widthwise position of the end of the slit hole in the second direction is the same as the widthwise position of the second end of the second rear end surface.

4. A gate as described in claim 2, wherein the thickness of the gate body in the front-to-rear direction at the first side end and the second side end is the same as the thickness of the gate body in the front-to-rear direction at the portion between the slit hole and the seal surface.

5. A gate according to claim 2, wherein the shaft mounting portion bulges rearward in the front-to-rear direction beyond the first rear end surface and the second rear end surface.

6. A gate as claimed in claim 1, wherein the thickness (T1) in the front-to-rear direction of the contact portion between the slit hole and the sealing surface of the gate body is thinner than the thickness (T2) in the front-to-rear direction of the arm portion between the slit hole and the rear surface.

7. A gate according to claim 1, wherein the length of the slit in the width direction is at least half the length of the gate body in the width direction.

8. A gate as described in claim 1, wherein the shaft mounting portion has an upper end wall (92) that extends flush with the upper end surface and closes the upper end of the shaft mounting hole, and a fastening hole (62) that penetrates the upper end wall in the vertical direction and through which a fastening member (94) that fastens the shaft is inserted.

9. A slit valve comprising: a gate according to any one of claims 1 to 8; a shaft attached to the shaft attachment hole; and a drive mechanism (30) that performs an opening and closing operation to displace the shaft in the up and down direction, and a clamping operation to displace the shaft in the front and back direction.

10. A slit valve according to claim 9, further comprising a body (24) for housing said gate and having said opening opened and closed by said gate.

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