Holding unit

Abstract

To provide a holding unit capable of inspecting whether or not an object can be appropriately held by a holding table.SOLUTION: A holding unit that holds an object with a holding surface of a holding table, comprises: a fixing mechanism for fixing the object to the holding surface; a movement mechanism moving the fixing mechanism; and a determination part. The fixing mechanism comprises: a pressing member that can be arranged to a fixing position for pressing the object and fixing them to the holding surface and a releasing position where the object is released; and an energization member that energizes the pressing member to a fixing position side. The movement mechanism comprises: a pressing member that presses the pressing member; and an actuator that moves the pressing member, and positions the pressing member to the releasing position. A determination part determines whether or not the energization member is in a normal state or an abnormal state on the basis of a pressing force of the actuator when the pressing member is moved to the releasing position from the fixing position.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004] , , ,

[0001] The present invention relates to a holding unit that holds an object on a holding surface of a holding table.

Background Art

[0002] In the manufacturing process of device chips, a wafer in which devices are formed in a plurality of regions partitioned by a plurality of streets (division planned lines) arranged in a lattice pattern is used. By dividing this wafer along the streets, chips (device chips) provided with devices can be obtained. The device chips are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] For dividing a wafer, a cutting device that cuts the wafer with an annular cutting blade is used. On the other hand, in recent years, the development of a process for dividing a wafer by laser processing using a laser processing device has also been promoted. For example, Patent Document 1 discloses a method of condensing a laser beam having permeability to a wafer inside the wafer and forming a modified layer (altered layer) along the streets inside the wafer. The region where the modified layer of the wafer is formed becomes more brittle than other regions. Therefore, when an external force is applied to the wafer in which the modified layer is formed along the streets, the wafer breaks along the streets and is divided into a plurality of device chips.

[0004] When the wafer is divided by applying an external force, the dust generated at the fracture surface during division scatters and adheres to the wafer, which causes deterioration in the quality of the wafer and device chips. Therefore, a dividing device that divides the wafer while holding it downward has been proposed (see Patent Documents 2 and 3). When this dividing device is used, the dust generated during the division of the wafer falls below the wafer, so it is difficult for the dust to adhere to the divided wafer. Then, the divided wafer is conveyed to a cleaning unit mounted on the dividing device, and the cleaning unit holds the wafer downward and cleans it.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2005-129607 [Patent Document 2] Japanese Patent Publication No. 2020-96177 [Patent Document 3] Japanese Patent Publication No. 2021-15998 [Overview of the project] [Problems that the invention aims to solve]

[0006] Cutting machines, laser processing machines, and other processing machines are equipped with a holding table that holds the workpiece during processing and cleaning. The holding table has a holding surface for holding the object, and multiple clamping mechanisms are provided around the holding table to secure the object. The object is held by the holding table by supporting it with the holding surface and gripping its outer periphery with the multiple clamping mechanisms.

[0007] The clamping mechanism includes a clamping member that holds an object and fixes it to the holding surface of the holding table. The clamping member is biased by a biasing member such as a coil spring. When holding an object on the holding table, the biasing force (restoring force) applied to the clamping member by the biasing member presses the clamping member against the object, fixing the object to the holding surface of the holding table. On the other hand, when transporting an object from the holding table, an external force is applied to move the clamping member in the direction opposite to the biasing force of the biasing member. As a result, the clamping member separates from the object, and the object is released.

[0008] However, if the biasing member deteriorates or malfunctions over time, sufficient biasing force may not be applied from the biasing member to the clamping member, resulting in incomplete fixing of the object by the clamping mechanism. As a result, the object may not be properly held during processing or cleaning, potentially leading to processing defects or cleaning defects. In particular, if the holding table holds the object facing downwards, a malfunction in the clamping mechanism may cause the object to fall, potentially resulting in irreparable damage to the object.

[0009] Therefore, when using a clamping mechanism to hold an object, it is necessary to monitor the condition of the clamping mechanism and promptly inspect, repair, or replace it if any abnormality occurs. However, deterioration or failure of biasing members is often difficult to judge from the outside, and abnormalities in the clamping mechanism are often discovered late. As a result, processing or cleaning may continue with the object not being held properly, making it impossible to avoid processing defects or cleaning defects.

[0010] This invention has been made in view of the above problems, and aims to provide a holding unit that can inspect whether or not an object can be properly held on a holding table. [Means for solving the problem]

[0011] According to one aspect of the present invention, a holding unit for holding an object on the holding surface of a holding table comprises a fixing mechanism for fixing the object to the holding surface, a moving mechanism for moving the fixing mechanism, and a determination unit, wherein the fixing mechanism comprises a pressing member that can be positioned in a fixed position for pressing and fixing the object to the holding surface and a release position for releasing the object, and a biasing member for biasing the pressing member toward the fixed position, and the moving mechanism comprises a pressing member for pressing the pressing member and a moving member for positioning the pressing member toward the release position. Air cylinder The determination unit includes the following, and when moving the retaining member from the fixed position to the released position The pressure of the air supplied to the air cylinder A holding unit is provided that determines whether the biasing member is in a normal or abnormal state based on this.

[0012] Preferably, the biasing member is a torsion coil spring. ru . [Effects of the Invention]

[0013] In a holding unit according to one aspect of the present invention, the biasing member is determined to be in a normal or abnormal state based on the pressing force of the actuator when moving the retaining member from a fixed position to a released position. This allows for the rapid detection of abnormalities in the biasing member, preventing the processing, cleaning, etc., of the object from continuing while the object is not properly secured. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view showing the holding unit. [Figure 2] This is a perspective view showing the retention table. [Figure 3] This is an exploded perspective view showing the fixing mechanism. [Figure 4] This is a perspective view showing the movement mechanism. [Figure 5] This is a side view showing the holding unit used when transporting an object. [Figure 6] This is a side view showing the holding unit used when fixing an object. [Modes for carrying out the invention]

[0015] Hereinafter, an embodiment according to one aspect of the present invention will be described with reference to the attached drawings. First, an example of the configuration of the holding unit according to this embodiment will be described. Figure 1 is a perspective view showing the holding unit (holding mechanism) 2. For example, the holding unit 2 is mounted on various processing devices such as cutting devices, grinding devices, polishing devices, laser processing devices, and plasma processing devices, and holds an object to be processed or cleaned by the processing device.

[0016] The holding unit 2 includes a plate-shaped base 4. The base 4 is made of metal, glass, ceramics, resin, etc., and has a first surface (lower surface) 4a and a second surface (upper surface) 4b that are generally parallel to each other. On the first surface 4a side of the base 4, a holding table (chuck table) 6 for holding a predetermined object is provided. In FIG. 1, for convenience of explanation, the base 4 and the holding table 6 are separated and illustrated at different angles.

[0017] FIG. 2 is a perspective view showing the holding table 6 that holds the object 11. The object 11 is an object to be held by the holding table 6, and the holding table 6 can hold various types of objects 11 according to the application. When the holding table 6 is mounted on a processing apparatus, the object 11 corresponds to a workpiece to be processed by the processing apparatus and a workpiece to be cleaned by the processing apparatus.

[0018] For example, the object 11 includes a disk-shaped wafer 13 made of a semiconductor material such as single crystal silicon. The wafer 13 has a surface 13a and a back surface 13b that are generally parallel to each other. Further, the wafer 13 is partitioned into a plurality of rectangular regions by a plurality of streets (division planned lines) 15 arranged in a lattice pattern so as to intersect each other. On the surface 13a side of the plurality of regions partitioned by the streets 15, devices 17 such as IC (Integrated Circuit), LSI (Large Scale Integration), LED (Light Emitting Diode), and MEMS (Micro Electro Mechanical Systems) devices are formed respectively.

[0019] For example, by using a processing apparatus such as a cutting apparatus, a laser processing apparatus, or a plasma processing apparatus to divide the wafer 13 along the streets 15 into individual pieces, a plurality of device chips each having a device 17 are manufactured. Also, by thinning the wafer 13 using a processing apparatus such as a grinding apparatus or a polishing apparatus before dividing the wafer 13, a thinned device chip can be obtained.

[0020] However, there are no restrictions on the material, shape, structure, size, etc., of the wafer 13. For example, the wafer 13 may be a substrate made of semiconductors other than silicon (GaAs, InP, GaN, SiC, etc.), glass, ceramics, resin, metal, etc. Furthermore, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc., of the devices 17, and the wafer 13 does not even need to have devices 17 formed on it.

[0021] When processing or cleaning the wafer 13, the wafer 13 is supported by an annular frame 19 for ease of handling. The frame 19 is made of a metal such as SUS (stainless steel), and a circular opening 19a is provided in the center of the frame 19, penetrating the frame 19 in the thickness direction. The diameter of the opening 19a is larger than the diameter of the wafer 13.

[0022] A sheet 21 is fixed to the wafer 13 and the frame 19. For example, the sheet 21 may be a tape containing a circularly formed film-like substrate and an adhesive layer (glue layer) provided on the substrate. The substrate is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate, and the adhesive layer is made of an epoxy, acrylic, or rubber-based adhesive. The adhesive layer may also be made of an ultraviolet-curable resin.

[0023] With the wafer 13 positioned inside the opening 19a of the frame 19, the central part of the sheet 21 is attached to the back surface 13b of the wafer 13, and the outer edge of the sheet 21 is attached to the frame 19. As a result, the wafer 13 is supported by the frame 19 via the sheet 21, and an object 11 (wafer unit, frame unit) including the wafer 13, frame 19, and sheet 21 is formed.

[0024] However, the configuration of the object 11 is not limited to the above. For example, instead of the wafer 13, a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate may be supported by the frame 19 via a sheet 21. The package substrate is formed by encapsulating multiple device chips mounted on a base substrate with a resin layer (molding resin). By dividing the package substrate into individual pieces, a package device comprising multiple packaged device chips is manufactured. Furthermore, the wafer 13 and the package substrate do not need to be supported by the frame 19 if there is no hindrance to handling. In this case, the wafer 13 or the package substrate itself corresponds to the object 11.

[0025] The holding table 6 comprises a disc-shaped frame (main body) 8 made of metal such as SUS (stainless steel), glass, ceramics, resin, etc. The frame 8 includes a first surface (bottom surface) 8a and a second surface (top surface) 8b that are generally parallel to each other. A cylindrical recess 8c is provided in the center of the first surface 8a side of the frame 8.

[0026] A disc-shaped holding member 10 made of a porous material such as porous ceramics is fitted into the recess 8c. The holding member 10 includes a flow path formed by a plurality of voids that communicate from the top surface to the bottom surface of the holding member 10. The bottom surface of the holding member 10 forms a circular suction surface 10a that attracts the object 11 when the object 11 is held by the holding table 6.

[0027] The depth of the recess 8c and the thickness of the retaining member 10 are approximately the same, and the first surface 8a of the frame 8 and the suction surface 10a of the retaining member 10 are arranged on approximately the same plane. The first surface 8a of the frame 8 and the suction surface 10a of the retaining member 10 form a retaining surface (support surface) 6a for holding the object 11. The suction surface 10a is connected to a suction source (not shown), such as an ejector, via a void in the retaining member 10, a flow path (not shown) formed inside the frame 8, a valve (not shown), etc.

[0028] For example, the object 11 is placed on the holding surface 6a side of the holding table 6 such that the front surface 13a side of the wafer 13 is exposed downwards and the back surface 13b side (sheet 21 side) of the wafer 13 faces the holding surface 6a. In this state, when the suction force (negative pressure) of the suction source is applied to the suction surface 10a, the wafer 13 is held in place by the holding table 6 via the sheet 21.

[0029] However, there are no restrictions on the configuration of the holding table that holds the object 11. For example, instead of the holding table 6, a holding table can be used which has grooves (suction grooves) formed on its holding surface for sucking the object 11. This type of holding table is made of a disc-shaped member made of metal, glass, ceramics, resin, etc., and the surface (bottom surface) of the holding table constitutes the holding surface. In addition, multiple suction grooves are provided on the holding surface side of the holding table, formed along the holding surface.

[0030] For example, the multiple suction grooves may be formed linearly, curvedly, or annularly across the entire holding surface of the holding table. Alternatively, the multiple suction grooves may be formed radially from the center of the holding table toward the outer edge. The multiple suction grooves are connected to a suction source via a flow path formed inside the holding table. With the object 11 in contact with the holding surface, the suction force of the suction source is applied to the multiple suction grooves, thereby holding the object by suction on the holding surface of the holding table.

[0031] As shown in Figure 1, the holding table 6 is installed on the underside of the base 4 such that the second surface 8b of the frame 8 faces the first surface 4a of the base 4. This ensures that the holding surface 6a of the holding table 6 is positioned approximately parallel to the first surface 4a and the second surface 4b of the base 4. The base 4 and the holding table 6 may be connected to each other, or they may be supported independently by different members.

[0032] Furthermore, the holding unit 2 is equipped with multiple clamping mechanisms 12 that grip and fix the outer periphery of the object 11. For example, the clamping mechanisms 12 are arranged on the outer periphery of the holding table 6 at roughly equal intervals along the circumferential direction of the holding table 6. Although Figure 1 shows an example in which four sets of clamping mechanisms 12 are arranged at 90° intervals, the number and spacing of the clamping mechanisms 12 can be freely set.

[0033] Each clamping mechanism 12 includes a fixing mechanism 14 for fixing the object 11 (see Figure 2) to the holding surface 6a of the holding table 6, and a moving mechanism 16 for moving the fixing mechanism 14. For example, the fixing mechanism 14 is attached to the outer circumference of the frame 8 of the holding table 6 and is positioned together with the holding table 6 on the first surface 4a side (lower side) of the base 4. On the other hand, the moving mechanism 16 is positioned on the second surface 4b of the base 4.

[0034] The fixing mechanism 14 is configured to switch between a fixed state in which the outer periphery of the object 11 (frame 19, see Figure 2) is pressed from below towards the holding surface 6a of the holding table 6, and a released state in which the pressure on the outer periphery of the object 11 is released. When the fixing mechanism 14 is in the fixed state, the outer periphery of the object 11 is pressed from below towards the holding surface 6a of the holding table 6, and the object 11 is fixed to the holding surface 6a. On the other hand, when the fixing mechanism 14 is released, the fixing mechanism 14 separates from the outer periphery of the object 11, and the object 11 is released from being fixed.

[0035] Figure 3 is an exploded perspective view showing the fixing mechanism 14. The fixing mechanism 14 includes a fixing member 20 that is fixed to the outer periphery of the holding table 6 (see Figures 1 and 2). The fixing member 20 includes a rectangular plate-shaped fixing portion 20a and a pair of plate-shaped support portions 20b that protrude forward from both ends of the fixing portion 20a. The fixing portion 20a and the support portions 20b are arranged approximately vertically, and the pair of support portions 20b are arranged approximately parallel to each other. Each of the pair of support portions 20b is provided with a circular through-hole 20c that penetrates the support portion 20b in the thickness direction.

[0036] The fixing member 20 is fitted with a pressing member 22 that holds the object 11 (see Figure 2) and a biasing member 28 that presses and biases the pressing member 22. The pressing member 22 comprises a contact member 24 that contacts the outer circumference of the object 11 (see Figure 2) to fix the object 11, and a columnar pressing pin 26 connected to the contact member 24.

[0037] For example, the contact member 24 is formed in a substantially L-shape and is rotatably installed between a pair of support parts 20b. One end of the contact member 24 is provided with a contact portion 24a that contacts the object 11. The contact portion 24a is a projection (convex portion) that protrudes from one end of the contact member 24, and the tip of the contact portion 24a is formed in a curved shape. A pressing pin 26 is connected to the other end of the contact member 24. For example, the pressing pin 26 is inserted into a through hole 24b provided at the other end of the contact member 24 and fixed so as to be along the thickness direction of the contact member 24. Furthermore, a circular through hole 24c is provided between the contact portion 24a and the through hole 24b of the contact member 24, penetrating the contact member 24 in the thickness direction.

[0038] A biasing member 28 is connected to the retaining member 22. The biasing member 28 is an elastic body such as a coil spring, and biases the retaining member 22 by pressing it with its restoring force. For example, a torsion coil spring (torsion spring, kick spring) can be used as the biasing member 28. However, there are no restrictions on the type of biasing member 28 as long as it is possible to bias the retaining member 22.

[0039] The retaining member 22 and the biasing member 28 are positioned between a pair of support parts 20b. A columnar support pin 30 is then inserted sequentially into the through hole 20c of one support part 20b, the biasing member 28, the through hole 24c of the contact member 24, and the through hole 20c of the other support part 20b, and a fastener 32 is attached to the tip of the support pin 30. As a result, the support pin 30 is fixed to the fixing member 20, and the retaining member 22 and the biasing member 28 are supported by the support pin 30.

[0040] The retaining member 22 is supported by the support pin 30 in a manner that allows it to rotate around the support pin 30. One end of the biasing member 28 is fixed to the support pin 30, and the other end of the biasing member 28 is fixed, for example, to the upper end of the fixing portion 20a of the fixing member 20. The support pin 30 may be fitted with parts such as washers or cushioning rubber to prevent the movement of the retaining member 22 and the biasing member 28 along the length of the support pin 30.

[0041] When the pressing pin 26 is pressed against the fixing portion 20a of the fixing member 20, the biasing member 28 deforms and the pressing member 22 rotates in the direction of the pressure. As a result, the contact portion 24a of the contact member 24 moves away from the fixing portion 20a, and the pressing pin 26 moves closer to the fixing portion 20a. When the pressure on the pressing pin 26 is released, the biasing force (restoring force) of the biasing member 28 causes the pressing member 22 to rotate in the opposite direction to when it was pressed. As a result, the contact portion 24a of the contact member 24 moves closer to the fixing portion 20a, and the pressing pin 26 moves away from the fixing portion 20a.

[0042] Figure 4 is a perspective view showing the moving mechanism 16. The moving mechanism 16 includes a pressing member 42 that presses against the retaining member 22 (see Figure 3) of the fixing mechanism 14, and an actuator 44 that moves the pressing member 42. For example, the moving mechanism 16 is installed on a support base 40 fixed to the second surface 4b side of the base 4.

[0043] The pressing member 42 comprises a rectangular plate-shaped support portion 42a and a plate-shaped pressing portion 42b that protrudes forward from the side end of the support portion 42a. The support portion 42a and the pressing portion 42b are arranged approximately vertically. The height of the pressing portion 42b is greater than the height of the support portion 42a, and the lower end of the pressing portion 42b is positioned below the lower surface of the support portion 42a.

[0044] Furthermore, the base 4 is provided with a slit (through hole) 4c extending from the first surface 4a to the second surface 4b. The slit 4c is formed linearly along the radial direction of the holding table 6 (see Figure 1) and penetrates the base 4 in the thickness direction. The lower end of the pressing portion 42b is inserted into the slit 4c and protrudes downward from the first surface 4a of the base 4 (see Figures 5 and 6).

[0045] An actuator 44 is connected to the pressing member 42. The actuator 44 is a linear actuator that moves (reciprocates) the pressing member 42 along a linear movement path that is generally parallel to the slit 4c. For example, an air cylinder is used as the actuator 44. Specifically, the actuator 44 comprises a cylindrical cylinder 46 and a plurality of rods 48 housed in the cylinder 46. Connecting members 50 for connecting the rods 48 to other members are connected to the tips of the plurality of rods 48. The support portion 42a of the pressing member 42 is fixed to the connecting member 50 by fasteners such as screws.

[0046] The cylinder 46 contains a piston (not shown) that divides the inside of the cylinder 46 into a first chamber and a second chamber, and multiple rods 48 are fixed to the piston. The cylinder 46 is also provided with an air supply port 46a connected to the first chamber and an air supply port 46b connected to the second chamber.

[0047] Air supply ports 46a and 46b are each connected to an air supply source 52 that supplies air. A valve 54a is connected between air supply port 46a and air supply source 52. Valve 54a controls the pressure of the air supplied from air supply source 52 to the first chamber of cylinder 46 via air supply port 46a. Similarly, a valve 54b is connected between air supply port 46b and air supply source 52. Valve 54b controls the pressure of the air supplied from air supply source 52 to the second chamber of cylinder 46 via air supply port 46b. For example, pressure regulators are used as valves 54a and 54b.

[0048] With valve 54a closed and air supply port 46a open to the atmosphere, opening valve 54b and supplying air to air supply port 46b at a predetermined pressure causes rod 48 to move in the direction of being ejected from cylinder 46. As a result, the pressing portion 42b of pressing member 42 moves to one end of slit 4c (the outer peripheral edge side of base 4). On the other hand, with valve 54b closed and air supply port 46b open to the atmosphere, opening valve 54a and supplying air to air supply port 46a at a predetermined pressure causes rod 48 to move in the direction of being housed in cylinder 46. As a result, the pressing portion 42b of pressing member 42 moves to the other end of slit 4c (the center side of base 4).

[0049] As shown in Figure 1, the holding unit 2 includes a control unit (control unit, control device) 60 that controls the holding unit 2. The control unit 60 is connected to each component (movement mechanism 16, etc.) that constitutes the holding unit 2. The control unit 60 drives the holding unit 2 by generating control signals and outputting them to the components of the holding unit 2.

[0050] For example, the control unit 60 is comprised of a computer. Specifically, the control unit 60 comprises an arithmetic unit that performs various calculations necessary for driving the holding unit 2, and a storage unit that stores various information (data, programs, etc.) used for driving the holding unit 2. The arithmetic unit is comprised of a processor such as a CPU (Central Processing Unit), and the storage unit is comprised of memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0051] Furthermore, the holding unit 2 includes a notification unit (notification section, notification device) 62 that notifies the operator of information. For example, the notification unit 62 is a display unit (display section, display device) capable of displaying information, and is composed of a touch panel display or the like. The control unit 60 outputs a control signal to the notification unit 62, causing the notification unit 62 to display predetermined information (operation screen, message, image, etc.).

[0052] However, there are no restrictions on the type of notification unit 62. For example, the notification unit 62 may be an indicator light (warning light) or a speaker. An indicator light notifies the operator of predetermined information by lighting up or flashing. A speaker notifies the operator of predetermined information by emitting sound or voice.

[0053] For example, the notification unit 62 notifies the status of the holding unit 2 (normal or abnormal). This allows the operator to check the status of the holding unit 2 at any time and to take prompt action if an abnormality occurs in the holding unit 2. In the case where the holding unit 2 is mounted on a processing device, the control unit of the processing device may also serve as the control unit 60, or the notification unit of the processing device may also serve as the notification unit 62.

[0054] Next, the specific functions and operation of the holding unit 2 will be described. When the holding unit 2 holds the object 11, the control unit 60 outputs control signals to the valves 54a and 54b, thereby controlling the pressure of the air supplied to the first and second chambers of the cylinder 46, and driving the actuator 44.

[0055] Figure 5 is a side view showing the holding unit 2 during the transport of the object 11. First, valves 54a and 54b are controlled by the control unit 60, and air is supplied to the air supply port 46a at a predetermined pressure (for example, 0.5 MPa), while the air supply port 46b is opened to the atmosphere. As a result, the rod 48 moves in the direction toward being housed in the cylinder 46 and is positioned in the housing position. Also, the pressing portion 42b of the pressing member 42 moves to press the pressing pin 26.

[0056] When the pressing portion 42b of the pressing member 42 presses the pressing pin 26, the retaining member 22 rotates against the biasing force of the biasing member 28 due to the force applied by the pressing member 42. As a result, the retaining member 22 is positioned to release the object 11 (release position), and the contact portion 24a of the retaining member 22 is housed in the fixing member 20.

[0057] Next, the object 11 is transported by a transport mechanism (not shown) and positioned on the holding surface 6a of the holding table 6. In this state, when the suction force of the suction source is applied to the holding surface 6a, the object 11 is sucked in by the holding table 6.

[0058] Figure 6 is a side view showing the holding unit 2 when the object 11 is fixed in place. When the object 11 is placed on the holding surface 6a of the holding table 6, the valves 54a and 54b are controlled by the control unit 60, the air supply port 46a is opened to the atmosphere, and air is supplied to the air supply port 46b at a predetermined pressure (for example, 0.5 MPa). As a result, the rod 48 moves in the direction of being ejected from the cylinder 46 and is positioned at the ejection position. Also, the pressing portion 42b of the pressing member 42 moves away from the pressing pin 26.

[0059] When the pressing portion 42b of the pressing member 42 separates from the pressing pin 26, the retaining member 22 is biased and rotated by the biasing force (restoring force) applied by the biasing member 28. As a result, the retaining member 22 is positioned to hold the object 11 and fix it to the holding surface 6a of the holding table 6 (fixing position), and the contact portion 24a of the contact member 24 comes into contact with the outer circumference of the object 11 (frame 19, see Figure 2). Consequently, the outer circumference of the object 11 is pressed from below toward the holding surface 6a by the contact portion 24a and fixed to the holding surface 6a and the fixing member 20.

[0060] In this way, the outer periphery of the object 11 is gripped and fixed by the clamping mechanism 12, and the object 11 is held by the holding surface 6a of the holding table 6. After that, the transport mechanism detaches from the object 11.

[0061] When transporting the object 11 from the holding table 6, first, the object 11 is supported from below by a transport mechanism (not shown). Then, the suction force of the suction source acting on the holding surface 6a is released. Next, the rod 48 is housed in the cylinder 46 and positioned in the housing position, and the pressing member 22 is positioned in the release position (see Figure 5). As a result, the contact portion 24a of the contact member 24 is separated from the outer circumference of the object 11 and housed in the fixing member 20. Consequently, the pressure on the object 11 by the pressing member 22 is released, and the object 11 is released. After that, the object 11 is transported from the holding table 6 to a predetermined location by the transport mechanism.

[0062] Furthermore, if the biasing member 28 deteriorates or malfunctions over time, sufficient biasing force will not be applied from the biasing member 28 to the pressing member 22, resulting in incomplete fixing of the object 11 by the clamping mechanism 12. As a result, the object 11 may not be properly held during processing or cleaning, potentially leading to processing defects or cleaning defects. In particular, as shown in Figure 6, when the holding table 6 holds the object 11 facing downwards, a malfunction in the clamping mechanism 12 may cause the object 11 to fall, potentially resulting in irreparable damage to the object 11.

[0063] Therefore, in this embodiment, the state of the biasing member 28 is determined based on the pressing force of the actuator 44 that moves the clamping member 22. This makes it possible to quickly detect any abnormalities in the clamping mechanism 12 and prevents the processing, cleaning, etc., of the object 11 from continuing while the object 11 is not properly secured.

[0064] The state of the biasing member 28 is determined by the control unit 60. The control unit 60 includes a determination unit 60a that determines the state of the biasing member 28. The determination unit 60a determines whether the biasing member 28 is in a normal state or an abnormal state based on the pressing force that the actuator 44 applies to the retaining member 22 when moving the retaining member 22 from a fixed position to a released position.

[0065] Specifically, the determination unit 60a receives a signal (pressure signal) corresponding to the pressure applied by the actuator 44 to the retaining member 22. For example, the pressure of the air supplied from the air supply source 52 to the first chamber of the cylinder 46 via the valve 54a and the air supply port 46a corresponds to the pressure that moves the rod 48 from the ejection position to the storage position, that is, the pressure that moves the retaining member 22 from the fixed position to the release position. The control unit 60 then controls the valve 54a so that air is supplied to the first chamber of the cylinder 46 at a predetermined pressure, and inputs a signal indicating that predetermined pressure as a pressure signal to the determination unit 60a.

[0066] Furthermore, the determination unit 60a receives a signal (position signal) corresponding to the position of the retaining member 22. For example, the cylinder 46 has a built-in sensor 56 that detects the position of the rod 48. The sensor 56 detects the rod 48 when it is positioned in its storage position (see Figure 5).

[0067] When a predetermined amount of air is supplied from the air supply source 52 to the first chamber of the cylinder 46 via the valve 54a and the air supply port 46a, the rod 48 moves from the ejection position (see Figure 6) to the storage position (see Figure 5) and is housed in the cylinder 46. At the same time, the retaining member 22 is pressed by the pressing member 42 and rotates, moving from the fixed position (see Figure 6) to the released position (see Figure 5). As a result, the rod 48 is detected by the sensor 56. That is, the sensor 56 detects that the rod 48 is positioned in the storage position and the retaining member 22 is positioned in the released position. The sensor 56 then inputs a signal indicating the detection result as a position signal to the determination unit 60a.

[0068] For example, a magnetic sensor (magnetic cylinder sensor) can be used as the sensor 56. In this case, the sensor 56 determines the position of the rod 48 by detecting the magnetic field of a magnet incorporated in the rod 48. However, there are no restrictions on the type of sensor 56. For example, the sensor 56 may be an optical sensor that detects the rod 48 when the rod 48 approaches the sensor 56. Alternatively, the sensor 56 may be a switch such as a touch switch or a push button. In this case, when the rod 48 comes into contact with the switch, the switch is activated and the rod 48 is detected.

[0069] Alternatively, the sensor 56 may detect when the retaining member 22 is in the released position by detecting the piston housed in the cylinder 46 instead of the rod 48. Furthermore, instead of the sensor 56 that detects the piston or rod 48 of the actuator 44, a sensor that directly detects the retaining member 22 in the released position may be installed.

[0070] The determination unit 60a then determines whether the biasing member 28 is in a normal or abnormal state based on the pressure of the air supplied to the actuator 44 and the position of the retaining member 22. Specifically, first, the control unit 60 activates the sensor 56 to make the rod 48 detectable. Next, the control unit 60 outputs a control signal to the valve 54a, which supplies air to the first chamber of the cylinder 46 at a predetermined pressure via the air supply port 46a.

[0071] During normal operation of the actuator 44, the pressure supplied from valve 54a to the first chamber of cylinder 46 is set to a pressure (reference pressure) that allows the retaining member 22 to move from the fixed position (see Figure 6) to the released position (see Figure 5) against the biasing force (restoring force) of the normal biasing member 28. On the other hand, when inspecting the condition of the biasing member 28, air is supplied from valve 54a to the first chamber of cylinder 46 at a pressure lower than the reference pressure (reference pressure). For example, if the reference pressure is set to 0.5 MPa, the reference pressure can be set to less than 0.5 MPa (e.g., 0.1 MPa).

[0072] In this case, if the biasing member 28 is in a normal state and its biasing force (restoring force) is acting normally, even if air is supplied to the first chamber of the cylinder 46 at a reference pressure, the movement of the retaining member 22 and the pressing member 42 will be hindered by the biasing force of the biasing member 28. As a result, the rod 48 will not be housed in the cylinder 46 and will not be detected by the sensor 56.

[0073] On the other hand, if the biasing member 28 deteriorates over time or malfunctions, the biasing member 28 will enter an abnormal state, causing its biasing force (restoring force) to decrease or cease to function. As a result, even if the air pressure supplied to the first chamber of the cylinder 46 is the reference pressure, the retaining member 22 and the pressing member 42 move against the biasing force of the biasing member 28, and the rod 48 is housed in the cylinder 46. Consequently, the rod 48 is detected by the sensor 56.

[0074] Therefore, the determination unit 60a determines the state of the biasing member 28 based on whether or not the rod 48 is detected by the sensor 56 when air is supplied from the valve 54a to the cylinder 46 at a reference pressure. Specifically, if no signal indicating that the rod 48 has been detected is input from the sensor 56 when air is supplied from the valve 54a to the cylinder 46 at a reference pressure, the determination unit 60a determines that the biasing member 28 is in a normal state. On the other hand, if a signal indicating that the rod 48 has been detected is input from the sensor 56 when air is supplied from the valve 54a to the cylinder 46 at a reference pressure, the determination unit 60a determines that the biasing member 28 is in an abnormal state.

[0075] The result of the determination by the determination unit 60a is notified to the operator by the notification unit 62 (see Figure 1). For example, if the notification unit 62 is a display, the control unit 60 outputs a control signal to the notification unit 62, causing the notification unit 62 to display a message indicating the determination result. This ensures that the operator is promptly notified of any abnormality in the biasing member 28.

[0076] The specific processing for determining the state of the biasing member 28 can be freely configured. For example, the control unit 60 may control the valve 54a in stages and supply a reference pressure to the cylinder 46 that increases or decreases sequentially. Specifically, if the reference pressure is 0.5 MPa, the reference pressure may be supplied to the cylinder 46 that increases in increments of 0.1 MPa from 0.1 MPa to 0.4 MPa while the sensor 56 is activated. In this case, whether or not the rod 48 is detected by the sensor 56 is determined for each sequentially changing reference pressure. This makes it possible to determine at what pressure the air must be supplied to the cylinder 46 for the rod 48 to reach its housing position, and to evaluate the degree of deterioration (decrease in biasing force) of the biasing member 28.

[0077] Furthermore, the timing for inspecting the biasing member 28 can be freely set. For example, the state of the biasing member 28 can be determined between the time one object 11 is removed from the holding unit 2 and the time the next object 11 is held by the holding unit 2. This allows the state of the biasing member 28 to be checked in advance each time an object 11 is held by the holding unit 2. Also, if the holding unit 2 is mounted on a processing device, the inspection of the biasing member 28 may be performed during maintenance of the processing device.

[0078] As described above, in the holding unit 2 according to this embodiment, the biasing member 28 is determined to be in a normal or abnormal state based on the pressing force of the actuator 44 when moving the pressing member 22 from the fixed position to the release position. This makes it possible to quickly detect any abnormality in the biasing member 28 and prevent the processing, cleaning, etc., of the object 11 from continuing while the object 11 is not properly fixed.

[0079] In this embodiment, an example was described in which the holding unit 2 holds the object 11 facing downwards (see Figure 2), but the holding unit 2 may also hold the object 11 facing upwards. Specifically, the holding table 6 and the multiple fixing mechanisms 14 can be arranged on the second surface 4b side of the base 4, and the multiple moving mechanisms 16 can be arranged on the first surface 4a side of the base 4.

[0080] Furthermore, there are no restrictions on the use of the holding unit 2 according to this embodiment. For example, the holding unit 2 can be mounted on various processing devices such as cutting devices, grinding devices, polishing devices, and laser processing devices.

[0081] A cutting device includes a processing unit (cutting unit) that cuts the workpiece. The cutting unit is equipped with a spindle, and an annular cutting blade is attached to the tip of the spindle. The workpiece is cut by rotating the cutting blade and cutting into it.

[0082] The grinding machine includes a processing unit (cutting unit) for grinding the workpiece. The grinding unit is equipped with a spindle, and an annular grinding wheel with multiple grinding wheels is mounted on the tip of the spindle. The workpiece is ground by rotating the grinding wheel and bringing the grinding wheels into contact with the workpiece.

[0083] The polishing device includes a processing unit (polishing unit) for polishing the workpiece. The polishing unit is equipped with a spindle, and a disc-shaped polishing pad is attached to the tip of the spindle. By rotating the polishing pad and bringing it into contact with the workpiece, the workpiece is polished.

[0084] A laser processing apparatus includes a processing unit (laser irradiation unit) that irradiates a workpiece with a laser beam. The laser irradiation unit includes a laser oscillator that emits a laser of a predetermined wavelength and an optical system that guides the laser beam emitted from the laser oscillator to the workpiece. Laser processing is performed on the workpiece by irradiating it with a laser beam from the laser irradiation unit.

[0085] Furthermore, the holding unit 2 can also be mounted on a plasma processing apparatus that performs plasma etching on a workpiece. The plasma processing apparatus etches the workpiece by supplying an etching gas in a plasma state to the workpiece.

[0086] The processing apparatus described above is equipped with a chuck table that holds the workpiece during processing and a spinner table that holds and rotates the workpiece during cleaning. The holding unit 2 according to this embodiment can be used as a chuck table or spinner table mounted on the processing apparatus.

[0087] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of Symbols]

[0088] 11 Object (worked object, object to be cleaned) 13 wafers 13a Surface (first side) 13b Back side (2nd side) 15th Street (planned division line) 17 devices 19 frames 19a aperture 21 sheets 2. Holding unit (holding mechanism) 4 base 4a 1st side (bottom side) 4b 2nd side (top side) 4c Slit (Through Hole) 6. Holding Table 6a Holding surface (supporting surface) 8. Frame (main body) 8a 1st side (bottom side) 8b 2nd side (top side) 8c recess 10 Retaining member 10a Suction surface 12. Clamping mechanism 14 Fixing mechanism 16 Moving mechanism 20 Fixing member 20a Fixed part 20b Support part 20c through hole 22 Retaining member 24 Contact Member 24a Contact part 24b Through hole 24c through hole 26 Compression pins 28. Biasing member 30 support pins 32 fasteners 40 Support stand 42 Pressing member 42a Support part 42b Pressing part 44 Actuators 46 cylinders 46a, 46b Air supply port 48 rods 50 Connecting Members 52 Air supply source 54a, 54b valves 56 sensors 60 Control Unit (Control Unit, Control Device) 60a Judgment Unit 62. Notification Unit (Notification Section, Notification Device)

Claims

1. A holding unit that holds an object on the holding surface of a holding table, A fixing mechanism for fixing the object to the holding surface, A moving mechanism for moving the fixing mechanism, It comprises a determination unit and, The fixing mechanism comprises a pressing member that can be positioned in a fixing position for holding and fixing the object to the holding surface and a release position for releasing the object, and a biasing member that biases the pressing member toward the fixing position. The moving mechanism comprises a pressing member that presses against the retaining member, and an air cylinder that moves the pressing member to position the retaining member in the release position. The holding unit is characterized in that the determination unit determines whether the biasing member is in a normal state or an abnormal state based on the pressure of the air supplied to the air cylinder when the retaining member is moved from the fixed position to the released position.

2. The holding unit according to claim 1, characterized in that the biasing member is a torsion coil spring.

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