JP2018101719A - Drainage mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drainage mechanism capable of draining water accumulated on a flat plate reliably by a space saving configuration.SOLUTION: A drainage mechanism drains water (W) accumulated on the upper surface of a flat plate (31) by surface tension, and includes guide plates (50, 51) disposed at the outer peripheral part of the flat plate, while separated from the upper surface of the flat plate with a height less than the thickness (T) of the water accumulated by surface tension. The guide plate includes an overhang portion (52) overhanging further outside than the outer peripheral edge of the flat plate, and the water accumulated on the upper surface is introduced to the outside of the flat plate by causing capillary phenomenon at a gap (D1) formed by the upper surface of the flat plate and the lower surface of the guide plate, and the water reached the overhang portion is dropped by own weight thus draining the water accumulated on the upper surface of the flat plate. With such an arrangement, a drainage mechanism for draining water on the flat plate reliably with a space saving configuration is obtained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drainage mechanism for draining water accumulated on a flat plate.

  In a manufacturing process of a semiconductor device or the like, a cleaning device is used for cleaning a suction surface of a transport pad that transports a workpiece while sucking and holding the workpiece, cleaning the workpiece, and the like (for example, Patent Document 1). In this type of cleaning apparatus, the suction surface of the transport pad and the workpiece are cleaned while supplying cleaning water, and the suction surface of the transport pad and the workpiece are dried after cleaning.

JP 2010-94785 A

  The water used for cleaning by the cleaning device is drained through a predetermined flow path. However, when water adheres to the surface of the flat plate portion constituting the cleaning device, water may accumulate on the surface of the flat plate portion due to surface tension. If such a flat plate portion is located near the suction surface of the transport pad or the workpiece, the water accumulated on the surface of the flat plate portion may roll up for some reason and wet the suction surface of the pad or the workpiece. is there. For example, when the suction surface of the transport pad and the workpiece are dried by the air that is ejected, the air that is ejected may cause water to roll up on the flat plate.

  In order to prevent the water from staying in the flat plate part as described above, a special water-repellent finish is formed on the surface of the flat plate part, which is composed of inclined surfaces where water can easily flow downward. Measures such as applying can be considered. However, the configuration using the inclined surface has a problem that it is difficult to apply when the vertical space is restricted. Moreover, even if water-repellent processing is performed, there is a possibility that the accumulation of water due to surface tension may not be sufficiently eliminated, resulting in an increase in cost.

  This invention is made | formed in view of such a point, and it aims at providing the drainage mechanism which can drain | drain the water collected on the flat plate reliably by a space-saving structure.

  The present invention is a drainage mechanism for draining water accumulated on the upper surface of a flat plate by surface tension, and is disposed at the outer peripheral portion of the flat plate at a height equal to or less than the thickness of the water accumulated by surface tension and spaced from the upper surface of the flat plate A guide plate is provided, and the guide plate has a protruding portion that protrudes outward from the outer peripheral edge of the flat plate, and water collected on the upper surface of the flat plate is caused by capillary action in a gap formed by the upper surface of the flat plate and the lower surface of the guide plate The water collected on the flat plate is drained by guiding the water to the outside of the flat plate and dropping the water reaching the protruding portion by its own weight.

  According to this drainage mechanism, the water on the flat plate can be surely drained by the guide plate having a simple configuration including the portion facing the upper surface of the flat plate and the protruding portion located outside the outer peripheral edge of the flat plate. it can.

  ADVANTAGE OF THE INVENTION According to this invention, the drainage mechanism which can drain reliably the water collected on the flat plate with a space-saving structure can be obtained.

It is sectional drawing of the washing | cleaning apparatus provided with the drainage mechanism which concerns on this Embodiment, and a conveyance mechanism. It is a perspective view which shows a part of washing | cleaning apparatus and conveyance mechanism of FIG.

  Hereinafter, the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a cleaning device 10 having a drainage mechanism according to the present embodiment and a transport mechanism 11 having a transport pad 12 cleaned by the cleaning device 10. FIG. 2 is a perspective view showing the relationship between the cleaning device 10 and the transport pad 12. In FIG. 2, in order to make the configuration according to the present invention easy to see, the cleaning brush 20 configuring the cleaning device 10 is virtually indicated by an alternate long and short dash line with a position shifted from the actual position in FIG. 1.

  As shown in FIG. 1, the transport pad 12 includes a frame body 13 and a suction holding portion 14 that is held in a recess formed in the lower surface of the frame body 13, and includes a suction surface 15 that is the lower surface of the suction holding portion 14. It faces downward. The suction holding portion 14 is made of a porous member such as porous ceramics, and a suction force acting on the suction holding portion 14 by operating the suction means 16 conceptually shown in FIG. The workpiece can be held by suction on the suction surface 15.

  As shown in FIG. 1, the transport mechanism 11 has an operating arm 17 that supports the transport pad 12. The operating arm 17 can be moved in the vertical direction by the elevating means 18 and can be moved in the horizontal direction by the horizontal driving means 19. The horizontal movement by the horizontal driving means 19 can be arbitrary, such as rotation (turning) or linear movement around a rotation axis oriented in the vertical direction. By the operation of the operating arm 17 by the elevating means 18 and the horizontal driving means 19, the work piece held by the transport pad 12 is transported.

  As shown in FIG. 1, the cleaning apparatus 10 includes a cleaning brush 20 positioned below the transport pad 12 and a rotating unit 21 that rotationally drives the cleaning brush 20. The cleaning brush 20 is configured to hold the brush portion 23 on the holding member 22. The rotating means 21 rotates a rotating shaft 24 extending upward by a motor. The holding member 22 is supported at the tip of the rotating shaft 24, and the cleaning brush 20 rotates as the rotating shaft 24 rotates. A cleaning water spray nozzle 25 is provided in the vicinity of the cleaning brush 20. Wash water is supplied to the wash water injection nozzle 25 from the wash water supply source 26, and the wash water injection nozzle 25 ejects the wash water toward an obliquely upper position where the suction surface 15 of the transport pad 12 is located.

  As shown in FIG. 1, a cover 30 and a waterproof case 40 are provided below the cleaning brush 20. The waterproof case 40 is formed with an opening 41 penetrating in the vertical direction, and the rotating means 21 is located below the opening 41. The rotating shaft 24 protrudes above the waterproof case 40 through the opening 41. The cover 30 covers the opening 41, and the rotation shaft 24 penetrates the cover 30 and is fixed to the cover 30. Accordingly, the cover 30 rotates together with the rotating shaft 24.

  As shown in FIG. 2, the suction surface 15 of the transport pad 12 is circular. On the other hand, the cleaning brush 20 has a rectangular parallelepiped shape elongated in the radial direction of the suction surface 15 having a circular shape. The length of the cleaning brush 20 is approximately equal to the diameter of the suction surface 15. When the suction surface 15 is cleaned by the cleaning device 10, the transport pad 12 is lowered by the elevating means 18 in a state where the center of the suction surface 15 is aligned with the rotation center of the rotating shaft 24, and the suction surface 15 is moved to the brush portion 23. Then, the cleaning brush 20 is rotated by the rotating means 21 while the cleaning water is ejected from the cleaning water jet nozzle 25. Thereby, the suction surface 15 is cleaned.

  Various objects such as a semiconductor substrate, an inorganic material substrate, a semiconductor wafer on which a device is formed, an optical device wafer, and the like can be applied to the workpiece held and conveyed by the conveyance pad 12. Moreover, the conveyance of the workpiece by the conveyance mechanism 11 can be applied to various uses. As an example, the conveyance mechanism 11 can be used for carrying in and out of a grinding apparatus that grinds the workpiece with a grinding wheel. . In this case, grinding scraps or the like adhering to the suction surface 15 after the workpiece is ground can be washed away by the cleaning device 10.

  As shown in FIGS. 1 and 2, the cover 30 includes a disk-shaped flat plate 31 that is horizontally disposed below the cleaning brush 20 and a cylindrical portion 32 that extends downward from the outer peripheral edge of the flat plate 31. The bottom portion of the cylindrical portion 32 is open. A through hole through which the rotation shaft 24 passes is formed at the center of the flat plate 31. A space between the through hole and the rotary shaft 24 is closed in a watertight state.

  As shown in FIGS. 1 and 2, the waterproof case 40 has a flat bottom surface portion 42 that is horizontally disposed below the cover 30 and a cylindrical portion 43 that protrudes upward from the bottom surface portion 42. The inner peripheral surface of the cylindrical portion 43 forms the opening 41 described above. The cylindrical portion 43 has a smaller diameter than the cylindrical portion 32 of the cover 30, and the cylindrical portion 43 is located inside the cylindrical portion 32.

  In the cleaning device 10, the cleaning water supplied from the cleaning water jet nozzle 25 at the time of cleaning flows down below the cleaning brush 20. In particular, since the cleaning brush 20 having an elongated rectangular parallelepiped shape is positioned below the circular suction surface 15, the cleaning water is not stopped by the cleaning brush 20 and easily flows onto the flat plate 31 of the cover 30. The washing water that has flowed on the flat plate 31 of the cover 30 flows from the surface of the flat plate 31 to the outer peripheral side and falls on the bottom surface portion 42 of the waterproof case 40. Since the space between the through hole of the flat plate 31 and the rotary shaft 24 is in a watertight state, the cleaning water does not enter the opening 41 of the waterproof case 40 from the through hole of the flat plate 31. Further, since the cylindrical portion 43 is provided at the inner position of the cylindrical portion 32, the cleaning water that flows toward the bottom surface portion 42 along the outer peripheral surface of the cylindrical portion 32 does not flow into the opening 41. Therefore, the internal space of the waterproof case 40 provided with the rotating means 21 is kept watertight. And the washing water which fell on the bottom face part 42 is discharged | emitted out of the washing | cleaning apparatus 10 through the drainage path which abbreviate | omits illustration.

  During the cleaning in which the cleaning water is continuously supplied from the cleaning water jet nozzle 25, the cleaning water is discharged to the outside of the cleaning device 10 in the above-described flow. However, water may accumulate on the flat plate 31 of the cover 30 due to surface tension. In particular, after the cleaning operation of the suction surface 15 by the cleaning device 10 is completed and the supply of cleaning water is stopped, water drops adhering to the suction surface 15 and the cleaning brush 20 fall, so that water accumulates on the flat plate 31. Cheap. FIG. 1 shows a state where water W has accumulated on the upper surface of the flat plate 31 due to surface tension.

  The suction surface 15 of the transport pad 12 after cleaning needs to be in a dry state in preparation for the next transport of the workpiece. Here, when the suction surface 15 is to be dried using the air that is blown out, there is a possibility that the water W collected on the upper surface of the flat plate 31 will roll up and wet the suction surface 15 or the like due to the momentum of the air. is there. Further, the water W on the flat plate 31 may be rolled up due to causes other than the ejection of drying air. Therefore, it is required to drain the water W collected on the flat plate 31 after the cleaning is completed.

  The washing apparatus 10 of the present embodiment is provided with a drainage guide plate 50 in order to surely drain the water accumulated on the flat plate 31 of the cover 30. As shown in FIGS. 1 and 2, the drainage guide plate 50 includes a first plate portion 51 disposed horizontally above the vicinity of the outer peripheral edge of the flat plate 31, and a lower radial position than the flat plate 31. And a second plate portion 52 extending in the direction. The first plate portion 51 and the second plate portion 52 each have a rectangular flat plate shape, and the drainage guide plate 50 is an L-shape that connects the end portions of the first plate portion 51 and the second plate portion 52. It is a member. As shown in FIG. 2, only one drain guide plate 50 is provided in a part of the cover 30 in the circumferential direction.

  In addition, the 2nd board part 52 in the drainage guide plate 50 may not be a flat plate like illustration, but an arc plate, a rod-shaped shape, etc. In addition, the illustrated drainage guide plate 50 is L-shaped in which the second plate portion 52 extends downward from the end portion of the first plate portion 51, but the second plate portion 52 is relative to the first plate portion 51. What is necessary is just to extend below, and it is not limited to the L-shape which the 2nd board part 52 connects to the edge part of the 1st board part 51. FIG.

  In FIG. 1, the structure around the drainage guide plate 50 is shown enlarged in a circled portion. The first plate portion 51 is supported with a predetermined gap D1 in the vertical direction with respect to the upper surface of the flat plate 31. As shown in an enlarged view of the circled portion in FIG. 1, the gap D <b> 1 (the height of the first plate portion 51 with respect to the upper surface of the flat plate 31) formed between the lower surface of the first plate portion 51 and the upper surface of the flat plate 31 is The thickness W is set to be equal to or less than the thickness T of the water W accumulated by the surface tension on the flat plate 31 (T ≧ D1).

  The first plate portion 51 has a portion facing the upper surface of the flat plate 31 with a gap D1, and a portion protruding outward in the radial direction from the outer peripheral edge of the flat plate 31, and the first plate protruding outward in the radial direction. A second plate portion 52 projects downward from the end portion of the plate portion 51. The second plate portion 52 is a protruding portion that is positioned so as to protrude outward in the radial direction from the outer peripheral edge of the flat plate 31, and has a predetermined gap D <b> 2 with respect to the outer peripheral surface of the cylindrical portion 32 of the cover 30. Opposite. A gap D2 formed between the outer peripheral surface of the cylindrical portion 32 and the second plate portion 52 is set to be larger than the interval of the gap D1 between the first plate portion 51 and the flat plate 31 described above.

  The drainage guide plate 50 is supported by the cover 30 via a support portion 53 that connects the first plate portion 51 and the flat plate 31. The support portion 53 is provided only in a partial region in the width direction of the first plate portion 51, and the portion where the support portion 53 does not exist is between the lower surface of the first plate portion 51 and the upper surface of the flat plate 31. The gap D1 is secured.

  In the cleaning device 10 having the above configuration, when water W accumulates on the upper surface of the flat plate 31 due to surface tension, the capillary tube is formed in the gap D1 formed by the lower surface of the first plate portion 51 of the drainage guide plate 50 and the upper surface of the flat plate 31. The phenomenon acts and water W collected on the upper surface of the flat plate 31 is guided to the outside of the flat plate 31. The water W guided by the capillary phenomenon passes through the space between the cylindrical portion 32 and the second plate portion 52 over the outer edge portion of the flat plate 31 and falls by its own weight. Thus, the water W collected on the upper surface of the flat plate 31 can be drained to the bottom surface portion 42 side using the drainage guide plate 50 having a simple configuration.

  In order to make the water W guided to the narrow gap D1 by the capillary phenomenon easily fall into a state where the water W falls from the gap D1, the vibration applied to the cleaning device 10 in addition to the water pressure and gravity acting on the water W, and the cover 30 An external force such as a centrifugal force generated by the rotation of can be used.

  Further, since the gap D2 between the outer peripheral surface of the cylindrical portion 32 and the second plate portion 52 is set to be larger than the gap D1 between the lower surface of the first plate portion 51 and the upper surface of the flat plate 31, the self-weight The falling water W can be smoothly flowed downward without stagnation.

  Note that the cover 30 rotates together with the cleaning brush 20 when rotating, but since the rotation speed of the cleaning brush 20 during cleaning is not high, the centrifugal force acting on the cover 30 is small. Therefore, it is difficult to shake off all the water W on the flat plate 31 only by the centrifugal force based on the driving force of the rotating means 21. On the other hand, according to the drainage mechanism of the present embodiment, the water W can be guided to the outer peripheral edge of the flat plate 31 using the drainage guide plate 50, so that it depends on conditions such as the rotational speed of the cover 30. The water W can be surely discharged from the flat plate 31 without any problem.

  Temporarily, unlike this Embodiment, it becomes difficult for water to collect by making the upper surface of the flat plate 31 into the inclined surface where the height from the bottom face part 42 becomes small toward the outer peripheral side from the center. However, since such an inclined surface occupies a larger range in the vertical direction than the horizontal plane, it is difficult to adopt in a structure in which there is no room in the vertical direction. In particular, in order to flow water smoothly, it is necessary to increase the inclination angle of the inclined surface, and a larger space is required in the vertical direction.

  Unlike the present embodiment, if a means for blowing off the water accumulated on the upper surface of the flat plate 31 by using air injection or the like is provided, the structure becomes complicated. In addition, there is a risk that the water droplets blown off adhere to unintended locations such as the suction surface 15.

  In contrast to these configurations, in the cleaning apparatus 10 according to the present embodiment, smooth drainage from the upper surface of the flat plate 31 downward can be realized with a simple configuration in which the drainage guide plate 50 is provided on the cover 30. it can. The amount of upward protrusion of the drainage guide plate 50 relative to the flat plate 31 is small corresponding to a very narrow gap D1 (less than the thickness T of the water W accumulated on the flat plate 31 by surface tension). Therefore, it can be arranged in a narrow space in the vertical direction compared to the above configuration in which the upper surface of the flat plate 31 is an inclined surface. In addition, since the drainage guide plate 50 is provided only in a part of the cover 30 in the circumferential direction (see FIG. 2), the space occupied in the circumferential direction can be small. Therefore, it can be a small, lightweight and space saving drainage mechanism. Further, the drainage mechanism provided with the drainage guide plate 50 induces the water W on the flat plate 31 to freely fall by utilizing the capillary phenomenon, so that there is no risk of water droplets greatly scattering during drainage.

  It is also possible to adopt a modified example different from the above embodiment. For example, in the above embodiment, the lower surface of the first plate portion 51 of the drainage guide plate 50 has a planar shape parallel to the upper surface of the flat plate 31 of the cover 30, but the above-described condition T ≧ D1 (on the flat plate 31). As long as the thickness T of the water W accumulated due to the surface tension T ≧ the gap D1) is satisfied, a configuration other than such a plane may be selected. As an example, the lower surface of the first plate portion 51 can be a surface that is inclined with respect to the upper surface of the flat plate 31, a surface that is partially uneven, or the like. It is preferable that the modification regarding the lower surface of the 1st board part 51 selects the form which improves the guidance effect | action of the water by a capillary phenomenon.

  The 2nd board part 52 of the drainage guide plate 50 in the said embodiment is a part which forms the flow path in which the water W which reached | attained the outer edge part of the flat plate 31 falls by its own weight, and can drop the water W by its own weight without delay. If possible, any configuration can be selected. For example, in the above embodiment, the second plate portion 52 has a flat plate shape. However, the second plate portion 52 may be a circular plate (such as a cylindrical shape along the cylindrical portion 32 of the cover 30) or a rod shape as described above. You may make it the shape. Furthermore, you may change the 2nd board part 52 to the cone shape etc. which become large in diameter as it progresses below.

  Unlike the above embodiment, the gap D2 between the second plate portion 52 of the drainage guide plate 50 and the cylindrical portion 32 of the cover 30 is changed to the gap D1 between the first plate portion 51 and the flat plate 31. It may be the same size. In this configuration, the water W is guided to the lower end position of the second plate portion 52 by the capillary phenomenon, and the water W falls by its own weight when the lower end position of the second plate portion 52 is exceeded.

  In the above-described embodiment, the drainage guide plate 50 is supported by the support portion 53, but the drainage guide plate 50 may be supported by other locations. For example, a support portion connected to the cylindrical portion 32 of the cover 30 can be provided on the second plate portion 52, or the drainage guide plate 50 can be supported by a support arm extending from the rotating shaft 24.

  In the above embodiment, drainage from the upper surface of the flat plate 31 of the cover 30 that rotates together with the cleaning brush 20 is targeted. However, if water is accumulated on the upper surface of the flat plate by surface tension, whether or not the flat plate rotates. The present invention can be applied regardless of the case. For example, the drainage mechanism of the present invention can be applied to a type in which the flat plate moves linearly in the horizontal direction, a type in which the flat plate is fixed and does not move, and the like.

  In the said embodiment, although the drainage guide plate 50 is provided in one place of the circumferential direction with respect to the circular flat plate 31, the structure of a drainage mechanism is not limited to this. The number and arrangement of the guide plates can be appropriately selected according to the required drainage performance and the surrounding structure. For example, a drain guide plate may be provided at a plurality of locations in the circumferential direction, or a drain guide plate that is wider or narrower in the circumferential direction than the drain guide plate 50 shown in the figure.

  Further, the length of the first plate portion 51 in the radial direction of the flat plate 31 and the length of the second plate portion 52 in the vertical direction in the drainage guide plate 50 can be appropriately changed.

  The present invention can be applied to a flat plate having an arbitrary shape such as a rectangle as well as a circular plate shape like the flat plate 31 of the above embodiment as a flat plate on which water to be drained is collected.

  The above embodiment is applied to the cleaning device 10 that cleans the suction surface 15 of the transport pad 12 with the cleaning brush 20. In contrast, a cleaning apparatus for cleaning a workpiece (for example, a semiconductor substrate, an inorganic material substrate, a semiconductor wafer on which a device is formed, an optical device wafer, or the like) sucked and held on the suction surface of the transfer pad is also used. The drainage mechanism of the present invention can also be applied. In this modification, the workpiece is cleaned using a cleaning member such as a sponge instead of the cleaning brush 20 of the above embodiment. Then, by applying the drainage mechanism according to the present invention, it is possible to prevent the water from rolling up from the upper surface of the flat plate to the workpiece as in the above embodiment.

  Further, the present invention is not limited to the cleaning device, and the present invention can be applied to a drainage mechanism in a chuck table of a cutting device, a chuck table of a grinding device, a drainage mechanism in other various processing devices, and the like.

  Moreover, although the embodiment of the present invention has been described, as another embodiment of the present invention, the above embodiment and modifications may be combined in whole or in part.

  The embodiments of the present invention are not limited to the above-described embodiments, and various changes, substitutions, and modifications may be made without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by technological advancement or another derived technique, the method may be used. Accordingly, the claims cover all embodiments that can be included within the scope of the technical idea of the present invention.

  As described above, the present invention has an effect that the water accumulated on the upper surface of the flat plate can be surely discharged in a space-saving manner, and in particular, a drainage mechanism mounted on a cleaning device or various processing devices. Useful for.

DESCRIPTION OF SYMBOLS 10 Cleaning apparatus 11 Conveyance mechanism 12 Conveyance pad 14 Adsorption holding | maintenance part 15 Adsorption surface 20 Cleaning brush 21 Rotating means 25 Washing water injection nozzle 30 Cover 31 Flat plate 32 Cylindrical part 40 Waterproofing case 41 Opening 42 Bottom part 43 Cylindrical part 50 Drainage guide plate 51 First plate part 52 Second plate part (extrusion part)
53 Support D1 Gap D2 Gap W Water

Claims (1)

A drainage mechanism for draining water accumulated by surface tension on the upper surface of a flat plate,
A guide plate disposed at an outer peripheral portion of the flat plate separated from the upper surface of the flat plate at a height equal to or less than the thickness of water accumulated by surface tension;
The guide plate includes a protruding portion that protrudes outward from the outer peripheral edge of the flat plate,
Capillary action is caused by a gap formed between the upper surface of the flat plate and the lower surface of the guide plate to induce water accumulated on the upper surface of the flat plate to the outside of the flat plate, and the water reaching the protruding portion is dropped by its own weight. A drainage mechanism characterized by draining water accumulated on the flat plate.

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