TWI893281B - Cleaning device - Google Patents

Abstract

[Question] A cleaning device is provided that can permanently isolate the space between the spindle unit and the cleaning chamber housing the worktable. [Solution] The seal that isolates the space between the housing and the spindle from the cleaning chamber contains a magnetic fluid that contacts the spindle. This seal can prevent solids from coming into contact with the space. As a result, wear on the seal caused by spindle rotation is reduced, ensuring that the space is permanently isolated from the cleaning chamber.

Description

Cleaning device

The present invention relates to a cleaning device.

In the manufacturing process of various electronic components, such as semiconductor device chips, cutting blades or laser beams are used to process plate-shaped workpieces, such as silicon wafers, glass substrates, and resin package substrates, on which devices are formed. During this process, cutting chips and debris, such as shavings, are generated and adhere to the front surface of the workpiece.

Therefore, after processing, the workpiece can be cleaned in a cleaning device, for example, having a cleaning chamber. The cleaning chamber houses a worktable with a flat holding surface and a nozzle that supplies cleaning liquid to the holding surface. Generally speaking, this worktable can generate negative pressure in the space above the holding surface to attract the workpiece, generate positive pressure in the space above the holding surface to separate the workpiece, and can rotate about a straight line passing through the center of the holding surface and perpendicular to the holding surface as its rotation axis.

Furthermore, this cleaning system can hold the back side of the workpiece against the work table by suction, while the work table rotates to supply cleaning liquid to the front side of the workpiece through a nozzle. This removes chips and debris adhering to the front side of the workpiece. The work table used in this manner is rotatably supported by the spindle unit.

The spindle unit consists of a main shaft that supports the work table and bearings that rotatably support the main shaft. The motor connected to the end of the main shaft rotates the work table and the main shaft together. To prevent grease and other lubricants inside the bearings from scattering, the main shaft and bearings are housed in a housing in the spindle unit.

Furthermore, the space on the worktable's retaining surface is connected to the negative and positive pressure supply pipes connected to the housing via a negative or positive pressure supply pipe formed inside the spindle and a space defined by an oil seal between the housing and the spindle, known as a variable pressure section. Furthermore, by operating the negative pressure supply source connected to the negative pressure supply pipe, negative pressure is generated in the space on the retaining surface, while by operating the positive pressure supply source connected to the positive pressure supply pipe, positive pressure is generated in the space on the retaining surface. Furthermore, lubricant is often applied to the interface between the oil seal and the spindle to prevent obstruction of spindle rotation.

Here, the spindle has an end that protrudes from the housing to connect to the worktable. Furthermore, the cleaning chamber that houses the worktable has an opening for inserting the spindle end. Therefore, the space between the housing and the spindle and the cleaning chamber may sometimes communicate through this opening. In this case, there is a risk that lubricant scattered from the bearings and/or lubricating oil scattered from the interface between the oil seal and the spindle may enter the cleaning chamber and adhere to the surface of the workpiece.

Therefore, in devices equipped with such a work chuck, a sealing member is typically provided to block the connection between the space on the work chuck side and the space on the spindle unit side (see, for example, Patent Document 1). This sealing member is constructed, for example, from a V-ring, with its lip contacting the rotatable sealed portion. Prior Art Patent Document

Patent Document 1: Japanese Patent Application Publication No. 2018-73930

Invention problem to be solved

When the sealing member contacts the rotatable sealed part, it is difficult to block the connection between the space on the work table side and the space on the spindle unit side over a long period of time because the sealing member will wear as the sealed part rotates.

In light of this, the present invention aims to provide a cleaning device that can permanently isolate the space on the side of the spindle unit from the cleaning chamber housing the worktable. Means for Solving the Problem

According to the present invention, a cleaning device is provided for cleaning a workpiece in a cleaning chamber. The cleaning device comprises: a worktable for holding the workpiece with a holding surface; a nozzle for supplying a cleaning liquid to the workpiece held on the worktable; and a spindle unit for rotatably supporting the worktable. The cleaning chamber houses the worktable and the nozzle. The spindle unit comprises: a spindle for supporting the worktable; a bearing for rotatably supporting the spindle; and a housing for housing a portion of the spindle and the bearing. A variable pressure portion and an open portion are provided between the housing and the spindle. The variable pressure portion is disposed between a negative pressure supply pipe and a positive pressure supply pipe connected to the housing, and a negative pressure supply pipe or a positive pressure supply pipe formed within the spindle and connected to the retaining surface, and is positioned farther from the work table than the bearing. The opening portion is disposed between the bearing and the variable pressure portion and is accessible via a through-hole formed in the housing or an opening pipe connected to the housing. The spindle has an end protruding from the housing. A portion of the cleaning chamber is defined by a cover member having an opening for inserting the end of the spindle. A seal is disposed between the cover member and the end of the spindle to block communication between the space between the housing and the spindle and the cleaning chamber. The seal comprises an annular magnet ring disposed on the inner circumference of the cover member defining the opening; and a magnetic fluid disposed inside the magnet ring and in contact with the end of the spindle.

Furthermore, in the present invention, the end portion of the main shaft preferably includes: a cylindrical sealed portion in contact with the magnetic fluid; and a cylindrical extension portion extending from the sealed portion toward the work table side and having the same diameter as the sealed portion. Effects of the Invention

In the present invention, the seal that blocks the connection between the space between the housing and the spindle and the cleaning chamber contains a magnetic fluid in contact with the spindle. Therefore, the present invention can block the connection between the space and the cleaning chamber without causing solids to come into contact. As a result, wear on the seal associated with spindle rotation is reduced, allowing the space to be blocked from the cleaning chamber for a long period of time.

Furthermore, in the present invention, an open portion is provided between the bearing and the variable pressure section. This prevents pressure fluctuations in the variable pressure section from leaking from the variable pressure section to the open portion, thereby suppressing pressure fluctuations around the bearing. This also prevents scattering of lubricants such as grease inside the bearing.

Furthermore, the presence of this opening suppresses pressure fluctuations around the seal, preventing the magnetic fluid contained within the seal from leaking out. Consequently, the space between the housing and the spindle can be effectively blocked from the cleaning chamber over a long period of time.

Form used to implement the invention

The embodiments of the present invention will be described with reference to the accompanying drawings. FIG1 is a perspective view schematically showing an example of a processing device (cutting device) equipped with a cleaning device. Furthermore, the X-axis direction (front-back direction) and the Y-axis direction (left-right direction) shown in FIG1 are mutually orthogonal on a horizontal plane. Furthermore, the Z-axis direction (up-down direction) is a direction perpendicular to the X-axis and Y-axis directions (a vertical direction).

The cutting device 2 shown in Figure 1 includes a base 4 that supports its various components. A rectangular opening 4a, with its longitudinal sides parallel to the X-axis, is formed on the top surface of the base 4. Within the opening 4a are located a movable table 6 and a dust and drip-proof cover 8, which expands and contracts with the movement of the movable table 6. Below the dust and drip-proof cover 8 is an X-axis movement mechanism (not shown) that moves the movable table 6 along the X-axis.

A work clamp 10 is mounted on the upper surface of the movable worktable 6. The work clamp 10 includes a disc-shaped porous plate 10a exposed above, which is used to attract and retain workpieces placed on the plate 10a. The top surface of the porous plate 10a is generally flat, serving as a holding surface for the workpiece. A suction path (not shown) is formed within the work clamp 10, one end of which is connected to a suction source (not shown), such as an ejector, located outside the work clamp 10.

The other end of the suction path reaches the porous plate 10a. Therefore, when the suction source is activated while the workpiece is placed on the holding surface, the workpiece can be sucked and held on the work clamp 10. Furthermore, the work clamp 10 is connected to a rotary drive source (not shown), such as a motor. When this rotary drive source is activated, the work clamp 10 rotates about a straight line passing through the center of the holding surface and perpendicular to the holding surface as its rotation axis.

A support structure 12 is provided near the opening 4a on the top surface of the base 4. This support structure 12 comprises a vertical portion 12a extending from the top surface of the base 4 in the Z-axis direction, and an arm portion 12b extending from the upper end of the vertical portion 12a in the Y-axis direction, extending beyond the opening 4a. A Y-axis movement mechanism 14 is provided on the front surface of the arm portion 12b.

The Y-axis direction moving mechanism 14 has a pair of Y-axis guide rails 16 fixed to the front surface of the arm 12b and extending along the Y-axis direction. A Y-axis moving plate 18 is connected to the front surface side of the pair of Y-axis guide rails 16 so as to be slidable along the pair of Y-axis guide rails 16.

A screw shaft 20 extending along the Y-axis is disposed between the pair of Y-axis guide rails 16. A motor (not shown) is connected to one end of the screw shaft 20 to rotate it. A nut (not shown) is provided on the surface of the screw shaft 20, where the spiral groove is formed, to accommodate balls, forming a ball screw. These balls roll on the surface of the rotating screw shaft 20.

That is, when the screw shaft 20 rotates, the balls circulate within the nut, causing the nut to move along the Y-axis. Furthermore, this nut is fixed to the rear surface of the Y-axis moving plate 18. Therefore, simply rotating the screw shaft 20 with the motor connected to one end of the screw shaft 20 causes the Y-axis moving plate 18 and the nut to move along the Y-axis.

A Z-axis movement mechanism 22 is mounted on the front surface of the Y-axis movement plate 18. The Z-axis movement mechanism 22 includes a pair of Z-axis guide rails 24 fixed to the front surface of the Y-axis movement plate 18 and extending along the Z-axis direction. A Z-axis movement plate 26 is connected to the front surface of the pair of Z-axis guide rails 24 so as to be slidable along the pair of Z-axis guide rails 24.

A screw shaft 28 extending along the Z axis is disposed between the pair of Z-axis guide rails 24. A motor 30 is connected to one end of the screw shaft 28 to rotate it. A nut (not shown) that houses balls is provided on the surface of the screw shaft 28, where the spiral grooves are formed, forming a ball screw. The balls roll on the surface of the rotating screw shaft 28.

That is, when the screw shaft 28 rotates, the balls circulate within the nut, causing the nut to move along the Z-axis. Furthermore, the nut is fixed to the rear surface of the Z-axis moving plate 26. Therefore, as long as the motor 30 rotates the screw shaft 28, the Z-axis moving plate 26 and the nut will move along the Z-axis.

A cutting unit 32 is fixed to the lower portion of the Z-axis moving plate 26. The cutting unit 32 comprises a cylindrical spindle housing 34, the longitudinal direction of which is parallel to the Y-axis. The spindle housing 34 houses a cylindrical spindle (not shown), the longitudinal direction of which is parallel to the Y-axis. This spindle is rotatably supported by the spindle housing 34.

The front end of the spindle protrudes from the spindle housing 34, and a cutting blade 36 having an annular cutting edge is mounted on the front end. In addition, the base end of the spindle is connected to a rotational drive source (not shown) for the cutting blade, such as a motor built into the spindle housing 34.

A camera unit 38 is mounted on the lower portion of the Z-axis moving plate 26, adjacent to the cutting unit 32 along the X-axis. The camera unit 38 includes a light source such as an LED (light-emitting diode), an objective lens, and a CCD (charge-coupled device) or CMOS (complementary metal oxide semiconductor) image sensor.

The processing of the workpiece in the cutting device 2 is carried out in the following order, for example. First, the imaging unit 38 images the workpiece that is attracted and held by the work clamp 10. Then, based on the image obtained by the imaging, the cutting unit 32 and the workpiece are aligned. Specifically, the Y-axis moving mechanism 14 and/or the Z-axis moving mechanism 22 adjust the position of the cutting unit 32, and/or the X-axis moving mechanism and/or the work clamp rotary drive source adjust the position and/or direction of the work clamp 10 that attracts and holds the workpiece.

Next, the cutting blade 36 is brought into contact with the workpiece while being rotated. Specifically, while the spindle, with the cutting blade 36 mounted on its tip, is being rotated by the cutting blade rotation drive source, the Y-axis movement mechanism 14 and/or the Z-axis movement mechanism 22 move the cutting unit 32, and/or the X-axis movement mechanism and/or the workpiece rotation drive source move the workpiece 10, which is suctioning and holding the workpiece. In this way, the workpiece can be subjected to the desired processing.

A cleaning device 40 is installed on the upper surface of the base 4, in front of the support structure 12. Figure 2 is a partially broken perspective view schematically showing the cleaning device 40. The cleaning device 40 includes a work clamp 42. The work clamp 42 has a disc-shaped porous plate 42a exposed above, and has the function of sucking and holding the workpiece placed on the porous plate 42a. The upper surface of the porous plate 42a is generally flat and serves as a holding surface for the workpiece.

A cleaning chamber body 44 is provided around the work clamp 42 to surround the work clamp 42. The cleaning chamber body 44 has a cylindrical outer wall 44a, an annular bottom wall 44b extending radially inward from the lower end of the outer wall 44a, and a cylindrical inner wall 44c extending vertically from the inner end of the bottom wall 44b.

An exhaust port (not shown) is provided on the outer wall 44a and is connected to an exhaust pump (not shown) via an exhaust pipe 46. A drain port 48 is provided on the bottom wall 44b, connected to a downwardly extending drain pipe 50. Furthermore, a plurality of (e.g., three) support legs 52 are fixed to the lower surface of the bottom wall 44b. These support legs 52 are arranged at approximately equal intervals along the circumference of the bottom wall 44b and support the cleaning chamber body 44.

A disc-shaped lid (not shown) is installed above the cleaning chamber body 44. The diameter of this lid is longer than the inner diameter of the outer peripheral wall 44a. Furthermore, by placing the lower surface of this lid in contact with the upper surface of the outer peripheral wall 44a, it prevents chips adhering to the workpiece or cleaning fluid used for cleaning from scattering onto the upper surface of the base 4 during cleaning of the workpiece.

Inside the outer peripheral wall 44a, a washing unit 54 and a drying unit 56 are arranged. Each of the washing unit 54 and the drying unit 56 has a tubular shaft 54a, 56a that can be inserted into the bottom wall 44b. The shafts 54a, 56a are tubular members that extend perpendicularly to the holding surface of the work table 42, outside the work table 42. A rotational drive source (not shown), such as a motor, is connected to the lower ends of the shafts 54a, 56a to rotate the shafts 54a, 56a.

Arms 54b and 56b are connected to the upper ends of shafts 54a and 56a. Arms 54b and 56b are tubular members that extend parallel to the holding surface of work table 42, a length equal to the distance from the upper ends of shafts 54a and 56a to the center of work table 42. Downward-facing nozzles 54c and 56c are provided at the front ends of arms 54b and 56b (the ends of arms 54b and 56b not connected to shafts 54a and 56a).

Furthermore, the shaft 54a and arm 54b are connected to a cleaning liquid supply source (not shown). Therefore, for example, if the shaft 54a is rotated to position the nozzle 54c above the work table 42, and cleaning liquid is supplied from the cleaning liquid supply source to the shaft 54a and arm 54b, the cleaning liquid can be supplied from the nozzle 54c to the holding surface of the work table 42.

Furthermore, the shaft 56a and arm 56b are connected to an air supply source (not shown). Therefore, for example, if the shaft 56a is rotated to position the nozzle 56c above the work table 42, and air is supplied from the air supply source to the shaft 56a and arm 56b, air can be supplied from the nozzle 56c to the holding surface of the work table 42.

The spindle unit 58 passes upward through the cylindrical space inside the inner peripheral wall 44c. The spindle unit 58 includes a spindle 60 made of, for example, a ferrous or ferrous alloy stainless steel. The spindle 60 is connected at its upper end to the work chuck 42, thereby supporting the work chuck 42. Furthermore, a motor 62 is connected to the lower end of the spindle 60. When the motor 62 is activated, the work chuck 42 rotates about a straight line passing through the center of the retaining surface and perpendicular to the retaining surface.

The motor 62 is supported vertically by a support mechanism 64. The support mechanism 64 comprises a plurality (e.g., three) of air cylinders 66 mounted on the motor 62. A support leg 68 is connected to the bottom of each air cylinder 66. Simultaneously operating the plurality of air cylinders 66 causes the motor 62 and the work clamp 42 to move upward and downward.

For example, when loading or unloading workpieces into the cleaning apparatus 40, the support mechanism 64 can be actuated to position the workpiece clamp 42 at a predetermined loading or unloading position. During cleaning of the workpieces, the workpiece clamp 42 is positioned below the loading or unloading position. FIG. 2 schematically illustrates the cleaning apparatus 40 with the workpiece clamp 42 positioned at the loading or unloading position.

A housing 70 and a cover member 72 are provided around the main spindle 60. Figure 3 is a partially cutaway side view schematically showing the main spindle 60, the housing 70, the cover member 72, and the like, and Figure 4 is a partially enlarged view of Figure 3. Furthermore, Figures 3 and 4 schematically show the cleaning device 40 with the work table 42 in the cleaning position.

The housing 70 has a cylindrical shape with an outer diameter shorter than the inner diameter of the inner peripheral wall 44c and is secured to the motor 62 via a connecting member (not shown). The outer ring of a bearing 74 is secured to the inner peripheral surface of the upper portion of the housing 70. The inner ring of the bearing 74 contacts the main shaft 60, rotatably supporting the main shaft 60.

Furthermore, three through-holes are arranged vertically in the housing 70, extending radially therethrough. Of these three through-holes, the one closest to the bearing 74 is connected to a tubular opening 76. Opening 76 connects the annular space (opening) A between the housing 70 and the spindle 60 with the space outside the housing 70. Alternatively, opening 76 may be omitted. In other words, opening A may be connected to the space outside the housing 70 via the through-holes.

The remaining two through-holes are connected to a tubular negative pressure supply pipe 78 and a positive pressure supply pipe 80, respectively. Negative pressure supply pipe 78 connects the annular space (variable pressure section) B between the housing 70 and the main shaft 60, which is farther from the bearing 74 than the opening A, to a negative pressure supply source (suction source) such as an ejector. Positive pressure supply pipe 80 connects the variable pressure section B to a positive pressure supply source such as a gas supply source.

Annular oil seals 82a and 82b are installed at the boundary between the open portion A and the variable pressure portion B, and at the boundary between the external space below the variable pressure portion B and the variable pressure portion B. Furthermore, the variable pressure portion B is connected to a negative or positive pressure supply pipe 60a formed inside the spindle 60. The negative or positive pressure supply pipe 60a is connected to the space on the retaining surface of the work clamp 42 via a flow path (not shown) formed inside the work clamp 42.

The cover member 72 has an annular top wall 72a and a cylindrical side wall 72b extending downward from the outer end of the top wall 72a. The inner diameter of the top wall 72a is longer than the inner diameter of the bearing 74. Furthermore, the outer diameters of the top wall 72a and the inner diameters of the side wall 72b are longer than the outer diameter of the inner peripheral wall 44c.

The upper end of the spindle 60, protruding from the housing 70, is inserted into the inner side of the top wall 72a. In other words, the cover member 72 has an opening for inserting the upper end of the spindle 60. Furthermore, an annular seal 84 is provided between the cover member 72 and the upper end of the spindle 60. This annular seal 84 blocks the space between the housing 70 and the spindle 60 (e.g., the open portion A and the variable pressure portion B) from communicating with the space on the side of the work clamp 42.

The seal 84 includes an annular magnetic ring 84a mounted on the inner circumference of the top wall 72a. The magnetic ring 84a is formed from a permanent magnet, with its north and south poles contacting a pair of annular spherical pieces 84b. A magnetic fluid 84c is provided between the spherical pieces 84b and the main shaft 60.

Magnetic fluid 84c is retained along the magnetic flux lines formed between magnetic ring 84a, spherical member 84b, and main shaft 60. Furthermore, magnetic fluid 84c is, for example, an alkyl naphthalene-based magnetic fluid containing ferromagnetic particles such as magnetite or manganese zinc ferrite and a surfactant. Alternatively, magnetic fluid 84c can be a fluorine oil-based magnetic fluid containing ferromagnetic particles and a surfactant.

Here, there is a risk that the fluid, namely the magnetic fluid 84c, may spread to the outside of the space between the main shaft 60 and the spherical member 84b due to the main shaft 60 tilting during transportation of the cleaning device 40. Preferably, the main shaft 60 has a shape that forms a magnetic field that can suppress the outflow of the magnetic fluid 84c even in such a situation.

Preferably, for example, the upper end of the main shaft 60, which protrudes from the housing 70 and is inserted into the opening (inside the top wall 72a) of the cover member 72, has a cylindrical sealed portion that contacts the magnetic fluid 84c, and an extension portion extending upward from this sealed portion and having the same diameter as the sealed portion. Even with this extension portion, even if the magnetic fluid 84c expands upward from the space between the main shaft 60 and the spherical member 84b, the outflow of the magnetic fluid 84c can be suppressed.

Furthermore, when the main shaft 60 rotates, friction between the main shaft 60 and the magnetic fluid 84c generates frictional heat. Furthermore, if the main shaft 60 is heated by frictional heat, there is a concern that the oil seals 82a and 82b may deteriorate.

Therefore, the magnetic force of the magnetic ring 84a is preferably set to be relatively weak within the limit of being able to maintain the amount of magnetic fluid 84c between the spherical member 84b and the main shaft 60 to block the communication between the two spaces. For example, the magnetic force of the magnetic ring 84a is preferably 400-800G.

Similarly, the thickness of the magnetic ring 84a should be set relatively thin, within the limits required to maintain a sufficient amount of magnetic fluid 84c between the spherical members 84b and the main shaft 60 to prevent the two spaces from being connected. For example, as shown in Figure 4, the thickness of the magnetic ring 84a should be set relatively thin to integrate the magnetic fluid 84c in contact with the pair of spherical members 84b without separating. Specifically, the thickness of the magnetic ring 84a is preferably 3-5 mm.

Furthermore, as shown in FIG3 , the lower surface of the top wall 72a of the cover member 72 is sufficiently close to the upper surface of the inner peripheral wall 44c of the cleaning chamber body 44 when the work table 42 is in the cleaning position. Therefore, in the cleaning apparatus 40, the cleaning chamber is defined by the cleaning chamber body 44, the lid disposed in contact with the upper surface of the outer peripheral wall 44a of the cleaning chamber body 44, the cover member 72, and the sealing portion 84.

The cleaning process of the workpiece in the cleaning device 40 included in the cutting device 2 is performed, for example, in the following sequence. First, the workpiece is placed on the work clamp 42 positioned at the loading/unloading position as described above. Then, after the work clamp 42 is moved to the cleaning position, the work clamp 42 is caused to suction and hold the workpiece.

Next, the lid is placed in contact with the upper surface of the outer wall 44a of the cleaning chamber body 44 to form the cleaning chamber. The shaft 54a is rotated to position the nozzle 54c of the cleaning unit 54 above the workpiece. With the cleaning chamber evacuated via the exhaust pipe 46, the worktable 42 is rotated while cleaning liquid is supplied from the nozzle 54c to the workpiece. This removes chips and other debris adhering to the front surface of the workpiece.

Next, the shaft 54a is rotated to retract the nozzle 54c of the cleaning unit 54 from above the workpiece, and the shaft 56a is rotated to position the nozzle 56c of the drying unit 56 above the workpiece. Next, while the work table 42 is rotated, air is supplied from the nozzle 56c to the workpiece. This removes any cleaning liquid or other substances that have adhered to the front surface of the workpiece.

Next, the shaft 56a is rotated so that the nozzle 56c of the drying unit 56 is retracted from above the workpiece. Next, the workpiece is unloaded from the workpiece 42 after the workpiece 42 is moved to the loading/unloading position. This completes the cleaning of the workpiece.

In the cleaning apparatus 40, the seal 84 that blocks the space between the housing 70 and the spindle 60 (e.g., the open portion A and the variable pressure portion B) from the cleaning chamber includes a magnetic fluid 84c that contacts the spindle 60. Therefore, in the cleaning apparatus 40, the space can be blocked from the cleaning chamber without causing solids to come into contact. As a result, wear of the seal 84 associated with the rotation of the spindle 60 is reduced, allowing the space to be blocked from the cleaning chamber for a long period of time.

Furthermore, in the cleaning device 40, an opening A is provided between the bearing 74 and the variable pressure section B. This prevents pressure fluctuations in the variable pressure section B, even if leakage occurs from the variable pressure section B to the opening A. This suppresses pressure fluctuations around the bearing 74. This also prevents scattering of lubricants such as grease located within the bearing 74.

Furthermore, the provision of this opening A suppresses fluctuations in pressure around the seal portion 84. This prevents the magnetic fluid 84c contained within the seal portion 84 from leaking out. Consequently, the space between the housing 70 and the spindle 60 can be effectively blocked from communicating with the cleaning chamber over a long period of time.

Furthermore, the structures and methods of the above-mentioned embodiments may be appropriately modified and implemented without departing from the scope of the purpose of the present invention.

2: Cutting device 4: Base 4a: Opening 6: Moving table 8: Dust and drip proof cover 10, 42: Work clamp 10a, 42a: Perforated plate 12: Support structure 12a: Vertical mounting unit 12b: Arm 14: Y-axis movement mechanism 16: Y-axis guide rail 18: Y-axis movement plate 20: Screw shaft 22: Z-axis movement mechanism 24: Z-axis guide rail 26: Z-axis movement plate 28: Screw shaft 30, 62: Motor 32: Cutting unit 34: Spindle housing 36: Cutting blade 38: Camera unit 40: Washing device 44: Washing chamber body 44a: Outer wall 44b: Bottom wall 44c: Inner wall 46: Exhaust pipe 48: Drain outlet 50: Drain pipe 52: Support leg 54: Washing unit 54a, 56a: Shaft 54b, 56b: Arm 54c, 56c: Nozzle 56: Drying unit 58: Spindle unit 60: Spindle 60a: Negative or positive pressure supply pipe 64: Support mechanism 66: Cylinder 68: Support leg 70: Housing 72: Cover member 72a: Top wall 72b: Side wall 74: Bearing 76: Open pipe 78: Negative pressure supply pipe 80: Positive pressure supply pipe 82a, 82b: Oil seal 84: Sealing part 84a: Magnetic ring 84b: Spherical part 84c: Magnetic fluid A: Open part B: Variable pressure part X, Y, Z: Directions

Figure 1 is a perspective view schematically showing an example of a processing device. Figure 2 is a partially broken perspective view schematically showing an example of a cleaning device. Figure 3 is a partially cutaway side view schematically showing the spindle, housing, and cover member. Figure 4 is an enlarged view of a portion of Figure 3.

60: Main shaft 60a: Negative or positive pressure supply pipe 70: Housing 72a: Top wall 74: Bearing 76: Open pipe 78: Negative pressure supply pipe 80: Positive pressure supply pipe 82a, 82b: Oil seal 84: Sealing part 84a: Magnetic ring 84b: Spherical element 84c: Magnetic fluid A: Open part B: Variable pressure part

Claims (5)

A cleaning device cleans a workpiece in a cleaning chamber. The cleaning device comprises: a workpiece holding the workpiece with a holding surface; a nozzle supplying a cleaning liquid to the workpiece held on the workpiece; and a spindle unit rotatably supporting the workpiece. The cleaning chamber accommodates the workpiece and the nozzle. The cleaning device is characterized in that: the spindle unit The work clamp comprises a main shaft supporting the work clamp; a bearing rotatably supporting the main shaft; and a housing accommodating a portion of the main shaft and the bearing, a pressure variable portion and an open portion being provided between the housing and the main shaft, the pressure variable portion being provided between a negative pressure supply pipe and a positive pressure supply pipe connected to the housing, and a negative pressure or positive pressure supply formed inside the main shaft and connected to a space on the holding surface. The main shaft has an end protruding from the housing, and a portion of the cleaning chamber is defined by a cover member having an opening for inserting the end of the main shaft. A sealing portion is provided between the cover member and the end of the main shaft to block the connection between the space between the cover and the main shaft and the cleaning chamber. The sealing portion comprises: an annular magnetic ring provided on the inner circumference defining the opening of the cover member; and a magnetic fluid provided on the inner side of the magnetic ring and in contact with the end of the main shaft. The magnetic force of the magnetic ring is 400-800G. A cleaning device as claimed in claim 1, wherein the end of the main shaft has: a cylindrical sealed portion in contact with the magnetic fluid; and a cylindrical extending portion extending from the sealed portion toward the side of the work table and having the same diameter as the sealed portion. The cleaning device of claim 1 or 2, wherein the magnetic ring has a thickness of 3 to 5 mm. The cleaning apparatus of claim 1 or 2, wherein no communication path other than the communication path provided with the sealing portion that blocks the communication therebetween is provided between the space between the bearing and the sealing portion and the cleaning chamber. The cleaning device of claim 3, wherein no communication path other than the communication path provided with the sealing portion that blocks the communication therebetween is provided between the space between the bearing and the sealing portion and the cleaning chamber.