JP7650588B2 - Cleaning Equipment - Google Patents

Description

The present invention relates to a cleaning device.

In the manufacturing process of various electronic components such as semiconductor device chips, plate-shaped workpieces such as silicon wafers on which devices are formed, glass substrates, or resin package substrates are processed using cutting blades or laser beams. When the workpieces are processed in this manner, cutting chips, debris, and other processing waste are generated and may adhere to the surface of the workpiece.

Therefore, after processing, the workpiece is washed, for example, in a washing device having a washing chamber that houses a chuck table with a flat holding surface and a nozzle that supplies a washing liquid to the holding surface. This chuck table is generally capable of sucking in the workpiece by generating negative pressure in the space above the holding surface, and of separating the workpiece from the workpiece by generating positive pressure in the space above the holding surface, and is also capable of rotating around a straight line that passes through the center of the holding surface and is perpendicular to the holding surface.

In this cleaning device, the back side of the workpiece is held by suction on the chuck table, and while the chuck table is rotating, cleaning liquid is supplied from a nozzle to the surface of the workpiece. This removes cutting chips or debris adhering to the surface of the workpiece. The chuck table used in this way is rotatably supported by a spindle unit.

The spindle unit has a spindle that supports the chuck table and a bearing that rotatably supports the spindle. The chuck table rotates together with the spindle when a motor connected to the end of the spindle operates. In addition, to prevent lubricants such as grease provided inside the bearing from scattering around, the spindle and bearings in the spindle unit are housed in a case.

Furthermore, the space above the holding surface of the chuck table is connected to a negative pressure supply pipe and a positive pressure supply pipe connected to the case via a negative or positive pressure supply pipe formed inside the spindle and a pressure variable section, which is a space defined by an oil seal between the case and the spindle. Negative pressure is generated in the space above the holding surface when the negative pressure supply source connected to the negative pressure supply pipe is operated, and positive pressure is generated in the space above the holding surface when the positive pressure supply source connected to the positive pressure supply pipe is operated. Note that lubricating oil is often provided at the interface between the oil seal and the spindle so as not to impede the rotation of the spindle.

Here, the spindle has an end that protrudes from the case so as to be connected to the chuck table. The cleaning chamber that houses the chuck table has an opening into which the end of the spindle is inserted. Therefore, the space between the case and the spindle may communicate with the cleaning chamber through this opening. In this case, there is a risk that lubricant scattered from the bearing and/or lubricating oil scattered from the interface between the oil seal and the spindle may get mixed into the cleaning chamber and adhere to the surface of the workpiece.

For this reason, devices with such a chuck table are generally provided with a seal member that blocks communication between the space on the chuck table side and the space on the spindle unit side (see, for example, Patent Document 1). This seal member is, for example, a V-ring, and is provided so that its lip portion comes into contact with the rotatable sealed portion.

JP 2018-73930 A

When the sealing member comes into contact with the rotatable sealed part, the sealing member wears out as the sealed part rotates, making it difficult to block communication between the space on the chuck table side and the space on the spindle unit side over a long period of time.

In view of this, the object of the present invention is to provide a cleaning device that can block communication between the space on the spindle unit side and the cleaning chamber that houses the chuck table for a long period of time.

According to the present invention, there is provided a cleaning device comprising a chuck table which holds a workpiece on a holding surface, a nozzle which supplies a cleaning liquid to the workpiece held on the chuck table, and a spindle unit which rotatably supports the chuck table, and which cleans the workpiece in a cleaning chamber which houses the chuck table and the nozzle, the spindle unit having a spindle which supports the chuck table, a bearing which rotatably supports the spindle, and a case which houses a part of the spindle and the bearing, a pressure variable section and an opening section are provided between the case and the spindle, the pressure variable section is provided between a negative pressure supply pipe and a positive pressure supply pipe which are connected to the case, and a negative pressure or positive pressure supply pipe which is formed inside the spindle and communicates with a space above the holding surface, and the pressure variable section is located closer to the chuck table than the bearing, a cleaning device in which the spindle has an end protruding from the case, a part of the cleaning chamber is defined by a cover member having an opening into which the end of the spindle is inserted, and a seal portion is provided between the cover member and the end of the spindle to block communication between the space between the case and the spindle and the cleaning chamber, the seal portion having an annular magnet ring provided on an inner circumferential surface defining the opening of the cover member, and a magnetic fluid provided inside the magnet ring and in contact with the end of the spindle , the magnetic force of the magnet ring is 400 to 800 G, and the thickness of the magnet ring is 3 to 5 mm .

Furthermore, in the present invention, it is preferable that the end of the spindle has a cylindrical sealed portion that contacts the magnetic fluid, and a cylindrical extending portion that extends from the sealed portion to the chuck table side and has the same diameter as the sealed portion. Also, in the present invention, it is preferable that no communication passage is provided between the space between the bearing and the seal portion and the cleaning chamber, other than the communication passage in which the seal portion is provided to block communication therebetween.

In the present invention, the seal that blocks communication between the space between the case and spindle and the cleaning chamber has a magnetic fluid that contacts the spindle. Therefore, in the present invention, communication between the space and the cleaning chamber is blocked without solids coming into contact with each other. As a result, wear on the seal that accompanies the rotation of the spindle is reduced, and communication between the space and the cleaning chamber can be blocked for a long period of time.

Furthermore, in the present invention, an open section is provided between the bearing and the pressure variable section. This suppresses pressure fluctuations around the bearing even if leakage occurs from the pressure variable section to the open section in response to pressure fluctuations in the pressure variable section. This suppresses scattering of lubricants such as grease provided inside the bearing.

In addition, when such an opening is provided, pressure fluctuations around the seal are also suppressed. This prevents the magnetic fluid contained in the seal from leaking out. As a result, communication between the space between the case and spindle and the cleaning chamber can be blocked for a long period of time.

FIG. 1 is a perspective view showing a schematic example of a processing apparatus. FIG. 2 is a partially cutaway perspective view illustrating an example of a cleaning device. FIG. 3 is a partially sectional side view that typically shows the spindle, the case, the cover member, and the like. FIG. 4 is a partially enlarged view of FIG.

An embodiment of the present invention will be described with reference to the attached drawings. FIG. 1 is a perspective view showing a schematic example of a processing device (cutting device) having a cleaning device. Note that the X-axis direction (front-back direction) and the Y-axis direction (left-right direction) shown in FIG. 1 are directions perpendicular to each other on a horizontal plane, and the Z-axis direction (up-down direction) is a direction (vertical direction) perpendicular to the X-axis direction and the Y-axis direction.

The cutting device 2 shown in FIG. 1 includes a base 4 that supports each component. A rectangular opening 4a with its longitudinal direction parallel to the X-axis direction is formed on the top surface of the base 4. A movable table 6 and a bellows-shaped dust-proof and drip-proof cover 8 that expands and contracts as the movable table 6 moves are provided within the opening 4a. An X-axis direction movement mechanism (not shown) that moves the movable table 6 along the X-axis direction is provided below the dust-proof and drip-proof cover 8.

A chuck table 10 is provided on the upper surface of the moving table 6. The chuck table 10 has a disk-shaped porous plate 10a exposed upward, and has the function of suction-holding a workpiece placed on the porous plate 10a. The upper surface of the porous plate 10a is generally flat, and serves as a holding surface for holding the workpiece. Inside the chuck table 10, a suction path (not shown) is formed, one end of which is connected to a suction source (not shown) such as an ejector provided outside the chuck table 10.

The other end of the suction path reaches the porous plate 10a. Therefore, when the suction source is operated with the workpiece placed on the holding surface, the workpiece is sucked and held on the chuck table 10. Furthermore, the chuck table 10 is connected to a chuck table rotation drive source (not shown), such as a motor. When the chuck table rotation drive source is operated, the chuck table 10 rotates around a rotation axis that passes through the center of the holding surface and is perpendicular to the holding surface.

A support structure 12 is provided near the opening 4a on the top surface of the base 4. The support structure 12 includes an erect portion 12a extending from the top surface of the base 4 along the Z-axis direction, and an arm portion 12b extending from the upper end of the erect portion 12a along the Y-axis direction so as to cross the opening 4a. A Y-axis direction movement mechanism 14 is provided on the front side of the arm portion 12b.

The Y-axis direction movement mechanism 14 is fixed to the front surface of the arm portion 12b and includes a pair of Y-axis guide rails 16 that extend along the Y-axis direction. A Y-axis movement plate 18 is connected to the front surface of the pair of Y-axis guide rails 16 in a manner that allows it to slide along the pair of Y-axis guide rails 16.

A screw shaft 20 extending along the Y-axis direction is disposed between the pair of Y-axis guide rails 16. A motor (not shown) for rotating the screw shaft 20 is connected to one end of the screw shaft 20. A nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 20 is provided on the surface of the screw shaft 20 on which a spiral groove is formed, forming a ball screw.

In other words, when the screw shaft 20 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Y-axis direction. This nut portion is also fixed to the rear side of the Y-axis moving plate 18. Therefore, when the screw shaft 20 is rotated by a motor connected to one end of the screw shaft 20, the Y-axis moving plate 18 moves along the Y-axis direction together with the nut portion.

A Z-axis direction moving mechanism 22 is provided on the front side of the Y-axis moving plate 18. The Z-axis direction moving mechanism 22 is fixed to the front side of the Y-axis moving plate 18 and has a pair of Z-axis guide rails 24 that extend along the Z-axis direction. A Z-axis moving plate 26 is connected to the front side of the pair of Z-axis guide rails 24 in a manner that allows it to slide along the pair of Z-axis guide rails 24.

A screw shaft 28 extending along the Z-axis direction is disposed between the pair of Z-axis guide rails 24. A motor 30 for rotating the screw shaft 28 is connected to one end of the screw shaft 28. A nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 28 is provided on the surface of the screw shaft 28 on which a spiral groove is formed, forming a ball screw.

In other words, when the screw shaft 28 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Z-axis direction. This nut portion is also fixed to the rear side of the Z-axis moving plate 26. Therefore, when the screw shaft 28 is rotated by the motor 30, the Z-axis moving plate 26 moves along the Z-axis direction together with the nut portion.

A cutting unit 32 is fixed to the lower part of the Z-axis moving plate 26. The cutting unit 32 has a cylindrical spindle housing 34 whose longitudinal direction is parallel to the Y-axis direction. The spindle housing 34 contains a cylindrical spindle (not shown) whose longitudinal direction is parallel to the Y-axis direction. This spindle is supported by the spindle housing 34 in a rotatable state.

The tip of the spindle protrudes outside the spindle housing 34, and a cutting blade 36 having an annular cutting edge is attached to this tip. The base end of the spindle is connected to a rotary drive source for the cutting blade (not shown), such as a motor, that is built into the spindle housing 34.

At a position adjacent to the cutting unit 32 in the X-axis direction, an imaging unit 38 is provided that is fixed to the bottom of the Z-axis moving plate 26. The imaging unit 38 includes, for example, a light source such as an LED (Light Emitting Diode), an objective lens, and an imaging element such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

The workpiece is processed in the cutting device 2, for example, in the following order. First, the imaging unit 38 captures an image of the workpiece held by suction on the chuck table 10. Next, based on the image obtained by this capture, the cutting unit 32 and the workpiece are aligned. Specifically, the Y-axis direction movement mechanism 14 and/or the Z-axis direction movement mechanism 22 adjust the position of the cutting unit 32, and/or the X-axis direction movement mechanism and/or the rotary drive source for the chuck table adjust the position and/or orientation of the chuck table 10 that holds the workpiece by suction.

Next, the cutting blade 36 is rotated and brought into contact with the workpiece. Specifically, while the cutting blade rotary drive source rotates the spindle with the cutting blade 36 attached to its tip, the Y-axis direction movement mechanism 14 and/or the Z-axis direction movement mechanism 22 move the cutting unit 32, and/or the X-axis direction movement mechanism and/or the chuck table rotary drive source move the chuck table 10, which holds the workpiece by suction. This allows the desired processing to be performed on the workpiece.

A cleaning device 40 is provided at a position in front of the support structure 12 on the upper surface of the base 4. FIG. 2 is a partially cutaway perspective view showing the cleaning device 40. The cleaning device 40 has a chuck table 42. The chuck table 42 has a disk-shaped porous plate 42a exposed upward, and has the function of suction-holding a 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 holding the workpiece.

A cleaning chamber body 44 is provided around the chuck table 42 and surrounds the chuck table 42. The cleaning chamber body 44 has a cylindrical outer peripheral wall 44a, an annular bottom wall 44b that extends radially inward from the lower end of the outer peripheral wall 44a, and a cylindrical inner peripheral wall 44c that stands upright from the inner end of the bottom wall 44b.

An exhaust port (not shown) is provided in the outer peripheral wall 44a, and this exhaust port is connected to an exhaust pump (not shown) via an exhaust pipe 46. A drain port 48 is provided in the bottom wall 44b, and a drain pipe 50 extending downward is connected to the drain port 48. A plurality of support legs 52 (e.g., three) are fixed to the underside of the bottom wall 44b. The plurality of support legs 52 are provided at approximately equal intervals along the circumferential direction of the bottom wall 44b, and support the cleaning chamber body 44.

A disk-shaped lid (not shown) is provided above the cleaning chamber body 44. The diameter of this lid is longer than the inner diameter of the outer peripheral wall 44a. The bottom surface of this lid is arranged to contact the top surface of the outer peripheral wall 44a, thereby preventing cutting chips attached to the workpiece or cleaning liquid used for cleaning from scattering on the top surface of the base 4 when the workpiece is cleaned.

A cleaning unit 54 and a drying unit 56 are arranged inside the outer peripheral wall 44a. The cleaning unit 54 and the drying unit 56 each have a pipe-shaped shaft portion 54a, 56a that is inserted into the bottom wall 44b. The shaft portions 54a, 56a are pipe-shaped members that extend outside the chuck table 42 in a direction perpendicular to the holding surface of the chuck table 42. A rotational drive source (not shown), such as a motor, for rotating the shaft portions 54a, 56a is connected to the lower end side of the shaft portions 54a, 56a.

The arms 54b, 56b are connected to the upper ends of the shafts 54a, 56a. The arms 54b, 56b are pipe-shaped members that extend in a direction parallel to the holding surface of the chuck table 42 with a length equivalent to the distance from the upper ends of the shafts 54a, 54a to the center of the chuck table 42. The tips of the arms 54b, 56b (the ends of the arms 54b, 56b that are not connected to the shafts 54a, 56a) are provided with nozzles 54c, 56c facing downward.

Furthermore, the shaft 54a and the arm 54b are connected to a cleaning liquid supply source (not shown). Therefore, for example, after the shaft 54a is rotated so that the nozzle 54c is positioned above the chuck table 42, when cleaning liquid is supplied from the cleaning liquid supply source to the shaft 54a and the arm 54b, the cleaning liquid is supplied from the nozzle 54c to the holding surface of the chuck table 42.

The shaft 56a and the arm 56b are also connected to an air supply source (not shown). Therefore, for example, after the shaft 56a is rotated so that the nozzle 56c is positioned above the chuck table 42, air is supplied from the air supply source to the shaft 56a and the arm 56b, and air is supplied from the nozzle 56c to the holding surface of the chuck table 42.

The spindle unit 58 passes vertically through the cylindrical space inside the inner peripheral wall 44c. The spindle unit 58 has a spindle 60 made of ferritic or martensitic stainless steel or the like. The upper end of the spindle 60 is connected to the chuck table 42 and supports the chuck table 42. A motor 62 is connected to the lower end of the spindle 60. When the motor 62 is operated, the chuck table 42 rotates around a rotation axis that passes through the center of the holding surface and is perpendicular to the holding surface.

The motor 62 is supported by a support mechanism 64 in such a manner that it can move up and down. The support mechanism 64 has multiple (e.g., three) air cylinders 66 attached to the motor 62, and a support leg 68 is connected to the bottom of each air cylinder 66. When the multiple air cylinders 66 are operated simultaneously, the motor 62 and the chuck table 42 rise and fall.

For example, when a workpiece is loaded or unloaded in the cleaning device 40, the support mechanism 64 is operated to position the chuck table 42 at a predetermined loading/unloading position, and when the workpiece is cleaned, the chuck table 42 is positioned at a cleaning position lower than the loading/unloading position. Note that FIG. 2 shows the cleaning device 40 in a schematic state with the chuck table 42 in the loading/unloading position.

A case 70 and a cover member 72 are provided around the spindle 60. FIG. 3 is a partially cross-sectional side view showing the spindle 60, the case 70, the cover member 72, etc., and FIG. 4 is a partially enlarged view of FIG. 3. Note that FIGS. 3 and 4 show the cleaning device 40 with the chuck table 42 in the cleaning position.

The case 70 has a cylindrical shape with an outer diameter shorter than the inner diameter of the inner peripheral wall 44c, and is fixed to the motor 62 via a connecting member (not shown). The outer ring of a bearing 74 is fixed to the inner peripheral surface of the upper part of the case 70. The inner ring of the bearing 74 contacts the spindle 60 to rotatably support the spindle 60.

The case 70 also has three through holes that penetrate the case 70 in the radial direction, lined up one above the other. Of these three through holes, the one closest to the bearing 74 is connected to a pipe-shaped open tube 76. The open tube 76 connects the annular space (open section) A between the case 70 and the spindle 60 to the space outside the case 70. The open tube 76 does not have to be provided. In other words, the open section A may be connected to the space outside the case 70 via a through hole that penetrates the case 70.

A pipe-shaped negative pressure supply pipe 78 and a positive pressure supply pipe 80 are connected to the remaining two through holes, respectively. The negative pressure supply pipe 78 connects the annular space (pressure variable part) B between the case 70 and the spindle 60, which is farther from the bearing 74 than the open part A, to a negative pressure supply source (suction source) such as an ejector. The positive pressure supply pipe 80 connects the pressure variable part B to a positive pressure supply source such as an air supply source.

Furthermore, annular oil seals 82a, 82b are provided at the boundary between the open section A and the pressure variable section B, and at the boundary between the external space below the pressure variable section B and the pressure variable section B. The pressure variable section B can also be 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 above the holding surface of the chuck table 42 via a flow path (not shown) formed inside the chuck table 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. The outer diameter of the top wall 72a and the inner diameter 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 case 70 is inserted inside the top wall 72a. In other words, the cover member 72 has an opening into which the upper end of the spindle 60 is inserted. In addition, between the cover member 72 and the upper end of the spindle 60, an annular seal portion 84 is provided that blocks communication between the space between the case 70 and the spindle 60 (e.g., the open portion A and the pressure variable portion B) and the space on the chuck table 42 side.

The seal portion 84 has an annular magnet ring 84a provided on the inner peripheral surface of the top wall 72a. The magnet ring 84a is made of a permanent magnet, and is provided so that the north pole and south pole are in contact with a pair of annular ball pieces 84b, respectively. In addition, a magnetic fluid 84c is provided between the ball pieces 84b and the spindle 60.

The magnetic fluid 84c is held along the magnetic flux lines formed between the magnet ring 84a and the ball piece 84b and the spindle 60. The magnetic fluid 84c is, for example, an alkylnaphthalene-based magnetic fluid containing ferromagnetic particles such as magnetite or manganese zinc ferrite and a surfactant. Alternatively, the magnetic fluid 84c may be a fluorine oil-based magnetic fluid containing ferromagnetic particles and a surfactant.

Here, when the cleaning device 40 is transported, the spindle 60 may be tilted, and this may cause the magnetic fluid 84c to spread outside the space between the ball pieces 84b of the spindle 60. It is preferable that the spindle 60 has a shape that creates a magnetic field that can prevent the magnetic fluid 84c from leaking out even in such a case.

For example, it is preferable that the upper end of the spindle 60, which protrudes from the case 70 and is inserted into the opening of the cover member 72 (inside the top wall 72a), has a cylindrical sealed portion that contacts the magnetic fluid 84c and an extension portion that extends upward from the sealed portion and has the same diameter as the sealed portion. When an extension portion is provided in this manner, the outflow of the magnetic fluid 84c is suppressed even if the magnetic fluid 84c spreads upward from the space between the ball pieces 84b of the spindle 60.

In addition, when the spindle 60 rotates, friction between the spindle 60 and the magnetic fluid 84c generates frictional heat. If the spindle 60 is heated by the frictional heat, for example, the oil seals 82a and 82b may deteriorate.

For this reason, it is preferable to weaken the magnetic force of the magnet ring 84a as long as it is possible to retain an amount of magnetic fluid 84c between the ball piece 84b and the spindle 60 that is sufficient to block communication between the two spaces described above. For example, it is preferable that the magnetic force of the magnet ring 84a is 400 to 800 G.

Similarly, it is preferable that the thickness of the magnet ring 84a is as thin as possible while still being able to hold an amount of magnetic fluid 84c between the ball piece 84b and the spindle 60 that is sufficient to block communication between the two spaces described above. For example, it is preferable that the thickness of the magnet ring 84a is thin enough that the magnetic fluid 84c in contact with the pair of ball pieces 84b is integrated without separation, as shown in FIG. 4. Specifically, it is preferable that the thickness of the magnet ring 84a is 3 to 5 mm.

As shown in FIG. 3, the lower surface of the top wall 72a of the cover member 72 comes sufficiently close to the upper surface of the inner peripheral wall 44c of the cleaning chamber body 44 when the chuck table 42 is in the cleaning position. Therefore, in the cleaning device 40, the cleaning chamber is defined by the cleaning chamber body 44, the lid arranged to contact the upper surface of the outer peripheral wall 44a of the cleaning chamber body 44, the cover member 72, and the seal portion 84.

The cleaning of the workpiece in the cleaning device 40 included in the cutting device 2 is performed, for example, in the following order. First, the workpiece that has been machined as described above is placed on the chuck table 42 that is in the loading/unloading position. Next, the chuck table 42 is moved to the cleaning position, and the workpiece is then sucked and held on the chuck table 42.

Then, a lid is placed in contact with the upper surface of the outer peripheral wall 44a of the cleaning chamber body 44 to form a cleaning chamber, and the shaft 54a is rotated so that the nozzle 54c of the cleaning unit 54 is positioned above the workpiece. Next, with the cleaning chamber evacuated via the exhaust pipe 46, cleaning liquid is supplied to the workpiece from the nozzle 54c while rotating the chuck table 42. This removes cutting debris and the like adhering to the surface of the workpiece.

Then, the shaft 54a is rotated so that the nozzle 54c of the cleaning unit 54 is retracted from above the workpiece, and the shaft 56a is rotated so that the nozzle 56c of the drying unit 56 is positioned above the workpiece. Next, air is supplied to the workpiece from the nozzle 56c while rotating the chuck table 42. This removes the cleaning liquid and other substances adhering to the 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 chuck table 42 is moved to the loading/unloading position, and the workpiece is then unloaded from the chuck table 42. This completes the cleaning of the workpiece.

In the cleaning device 40, the seal portion 84, which blocks communication between the space between the case 70 and the spindle 60 (e.g., the open portion A and the pressure variable portion B) and the cleaning chamber, has a magnetic fluid 84c that contacts the spindle 60. Therefore, in the cleaning device 40, communication between the space and the cleaning chamber is blocked without solids coming into contact with each other. As a result, wear on the seal portion 84 caused by the rotation of the spindle 60 is reduced, and communication between the space and the cleaning chamber can be blocked for a long period of time.

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

In addition, when such an opening A is provided, pressure fluctuations around the seal portion 84 are also suppressed. This prevents the magnetic fluid 84c contained in the seal portion 84 from leaking out. As a result, communication between the space between the case 70 and the spindle 60 and the cleaning chamber can be blocked for a long period of time.

The structures and methods of the above-described embodiments can be modified as appropriate without departing from the scope of the present invention.

2: Cutting device 4: Base (4a: opening)
6: Moving table 8: Dust-proof/water-proof cover 10: Chuck table (10a: porous plate)
12: Support structure (12a: standing part, 12b: arm part)
14: Y-axis direction moving mechanism 16: Y-axis guide rail 18: Y-axis moving plate 20: Screw shaft 22: Z-axis direction moving mechanism 24: Z-axis guide rail 26: Z-axis moving plate 28: Screw shaft 30: Motor 32: Cutting unit 34: Spindle housing 36: Cutting blade 38: Imaging unit 40: Cleaning device 42: Chuck table (42a: porous plate)
44: cleaning chamber body (44a: outer peripheral wall, 44b: bottom wall, 44c: inner peripheral wall)
46: Exhaust pipe 48: Drain outlet 50: Drain pipe 52: Support leg 54: Cleaning unit (54a: shaft portion, 54b: arm portion, 54c: nozzle)
56: Drying unit (56a: shaft portion, 56b: arm portion, 56c: nozzle)
58: Spindle unit 60: Spindle (60a: negative or positive pressure supply pipe)
62: Motor 64: Support mechanism 66: Air cylinder 68: Support leg 70: Case 72: Cover member 74: Bearing 76: Release tube 78: Negative pressure supply tube 80: Positive pressure supply tube 82a, 82b: Oil seal 84: Sealing portion
(84a: magnet ring, 84b: ball piece, 84c: magnetic fluid)

Claims (3)

A cleaning device comprising: a chuck table that holds a workpiece on a holding surface; a nozzle that supplies a cleaning liquid to the workpiece held on the chuck table; and a spindle unit that rotatably supports the chuck table, and cleans the workpiece in a cleaning chamber that houses the chuck table and the nozzle,
The spindle unit comprises:
A spindle supporting the chuck table;
A bearing that rotatably supports the spindle;
a case that houses a portion of the spindle and the bearing;
A pressure variable portion and an opening portion are provided between the case and the spindle,
the pressure varying unit is provided between a negative pressure supply pipe and a positive pressure supply pipe connected to the case, and a negative pressure or positive pressure supply pipe formed inside the spindle and communicating with a space above the holding surface, and is disposed at a position farther from the chuck table than the bearing;
the opening is provided between the bearing and the pressure variable portion, and is opened via a through hole formed in the case or an opening pipe connected to the case;
The spindle has an end that projects from the case;
the washing chamber is defined in part by a cover member having an opening through which the end of the spindle is inserted;
a seal portion is provided between the cover member and the end of the spindle to block communication between the space between the case and the spindle and the cleaning chamber;
The seal portion is
an annular magnet ring provided on an inner circumferential surface of the cover member that defines the opening;
a magnetic fluid disposed inside the magnet ring and in contact with the end of the spindle ;
The magnetic force of the magnet ring is 400 to 800 G.
The cleaning device is characterized in that the thickness of the magnet ring is 3 to 5 mm . The cleaning device according to claim 1, wherein the end of the spindle has a cylindrical sealed portion that contacts the magnetic fluid and a cylindrical extension portion that extends from the sealed portion toward the chuck table and has the same diameter as the sealed portion. 3. The cleaning device according to claim 1, wherein there is no communication passage between the space between the bearing and the seal portion and the cleaning chamber other than the communication passage in which the seal portion is provided to block communication therebetween.

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