Processing apparatus and processing method for workpieces

Abstract

To efficiently transport the workpiece from the holding table without causing damage to the workpiece. [Solution] A processing apparatus for processing a workpiece, comprising: a holding table that holds the workpiece on a holding surface and from which a fluid containing liquid can be ejected; a processing unit for processing the workpiece held on the holding table; a transport unit that holds the workpiece held on the holding table in a transport section and transports the workpiece from the holding table; and a rotating section that rotates one or both of the holding table and the transport section around a rotation axis passing through the holding surface of the holding table, wherein when the workpiece held on the holding table is held by the transport section of the transport unit and removed from the holding table for transport, the rotating section is operated to rotate one or both of the holding table and the transport section while ejecting the fluid from the holding surface of the holding table, or after ejection.

Description

Technical Field

[0001] The present invention relates to a processing apparatus that processes a workpiece held by a holding table and transports the workpiece from the holding table, and a method for processing a workpiece.

Background Art

[0002] In the manufacturing process of device chips used in electronic devices such as mobile phones and personal computers, first, a plurality of planned division lines (streets) intersecting each other are set on the surface of a wafer made of a material such as semiconductor. Then, devices such as IC (Integrated Circuit) and LSI (Large-scale Integration) are formed in each region partitioned by the planned division lines. After that, the wafer is thinned by grinding from the back side and divided along the planned division lines, so that individual device chips are formed.

[0003] Grinding of a workpiece such as a wafer is performed by a grinding apparatus (see Patent Document 1) including a holding table (chuck table) and a grinding unit equipped with a grinding wheel having grinding wheels arranged in an annular shape. Further, division of the workpiece is performed by a cutting apparatus (see Patent Document 2) including a holding table and a cutting unit equipped with a cutting blade having an annular grindstone.

[0004] In a processing apparatus such as a grinding apparatus or a cutting apparatus, a workpiece sucked and held by a holding table is processed. After the processing of the workpiece, the suction holding of the workpiece by the holding table is released, and the workpiece is sucked and held by a transport unit (unloading arm) provided in the processing apparatus, and the workpiece is transported to the next process by the transport unit.

[0005] However, even after the suction holding of the workpiece by the holding table is released, the workpiece remains tightly attached to the holding table, requiring considerable force to detach it. However, workpieces have low mechanical strength, and those thinned by grinding equipment have extremely low mechanical strength. Therefore, forcibly detaching the workpiece from the holding table may cause damage.

[0006] Therefore, when transporting a workpiece from a holding table, a method is known in which a liquid (water) is sprayed from the holding surface of the holding table to reduce the adhesion between the workpiece and the holding table, while the discharge mechanism separates the workpiece from the holding table (see, for example, Patent Document 3). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2000-288881 [Patent Document 2] Japanese Patent Publication No. 2013-258235 [Patent Document 3] Japanese Patent Publication No. 2013-145776 Public Relations [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, even with this method, a large force due to the interfacial tension of the liquid (water) is applied to the workpiece during the process of moving the workpiece from a state where it is connected to the holding table via a liquid (water) to the air.

[0009] Therefore, in order to prevent damage to the workpiece, the unloading mechanism had to carefully and slowly remove the workpiece from the holding table until the interfacial tension of the liquid (water) was relieved, which meant that the unloading of the workpiece from the holding table took a considerable amount of time. This sometimes contributed to a decrease in the processing efficiency of the workpiece in the processing equipment.

[0010] This invention has been made in view of the above problems, and its objective is to provide a processing apparatus that can efficiently transport a workpiece held on a holding table from the holding table without damaging the workpiece, and a method for processing a workpiece. [Means for solving the problem]

[0011] According to one aspect of the present invention, a processing apparatus for processing a workpiece is provided, comprising: a holding table that holds the workpiece on a holding surface and from which a fluid containing liquid can be ejected; a processing unit for processing the workpiece held on the holding table; a transport unit that holds the workpiece held on the holding table in a transport section and transports the workpiece from the holding table; and a rotating section that rotates one or both of the holding table and the transport section around a rotation axis passing through the holding surface of the holding table, wherein when the workpiece held on the holding table is held by the transport section of the transport unit and removed from the holding table for transport, the rotating section is operated to rotate one or both of the holding table and the transport section while ejecting the fluid from the holding surface of the holding table, or after ejection.

[0012] Preferably, the system further includes a moving unit for moving the transport unit, and before the rotational operation, the moving unit moves the transport unit away from the holding surface of the holding table.

[0013] According to another aspect of the present invention, a processing method for processing a workpiece is provided, comprising: holding the workpiece on the holding surface of a holding table; processing the workpiece held on the holding table with a processing unit; holding the processed workpiece held on the holding table with a transport unit, removing the workpiece from the holding table, and transporting it, wherein, in transporting, a rotational operation is performed in which one or both of the holding table and the transport unit are rotated around a rotation axis passing through the holding surface of the holding table, while or after ejecting a fluid containing liquid from the holding surface of the holding table.

[0014] Preferably, before the rotational movement, the transporting part of the transporting unit is moved away from the holding surface of the holding table. [Effects of the Invention]

[0015] In a processing apparatus and workpiece processing method according to one aspect of the present invention, when transporting a workpiece from a holding table, a rotational operation is performed in which one or both of the holding table and the transport unit are rotated while a fluid is ejected from the holding surface of the holding table, or after the fluid has been ejected. When this rotational operation is performed, centrifugal force acts on the liquid contained in the fluid and supplied between the workpiece and the holding surface, causing the liquid to move out from between the workpiece and the holding surface.

[0016] Therefore, the influence of the interfacial tension of the liquid acting to connect the workpiece and the holding surface is greatly reduced, and no large force is applied to the workpiece when moving it from the holding table. In this case, it is not necessary to move the workpiece slowly and carefully from the holding table, and efficient removal of the workpiece from the holding table becomes possible. Therefore, the removal operation does not significantly reduce the efficiency of the workpiece processing process in the processing equipment.

[0017] Therefore, the present invention provides a processing apparatus that can efficiently transport a workpiece held on a holding table without damaging the workpiece, and a method for processing a workpiece.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view schematically showing a state where a protective member is attached to a workpiece. [Figure 2] It is a perspective view schematically showing a processing device and a workpiece. [Figure 3] It is a cross-sectional view schematically showing a workpiece held by a holding table. [Figure 4] It is a cross-sectional view schematically showing a workpiece being processed by a processing unit. [Figure 5] It is a cross-sectional view schematically showing a processed workpiece, a holding table for holding the workpiece, and a conveying unit positioned above the holding table. [Figure 6] It is a cross-sectional view schematically showing a workpiece or the like suction-held by a conveying unit. [Figure 7] It is a cross-sectional view schematically showing a workpiece or the like when the holding of the workpiece by the holding table is released. [Figure 8] It is a cross-sectional view schematically showing a workpiece or the like floating from a holding surface by the ejection of a fluid. [Figure 9] It is a cross-sectional view schematically showing a state where the holding table is rotated to remove the fluid. [Figure 10] It is a cross-sectional view schematically showing a workpiece being conveyed by a conveying unit. [Figure 11] FIG. 11(A) is a flowchart showing the flow of each stage of a method for processing a workpiece, and FIG. 11(B) is a flowchart showing the flow of each stage of a process for conveying a workpiece from a holding table.

Embodiments for Carrying Out the Invention

[0019] Embodiments according to the present invention will be described with reference to the drawings. In the processing device and the method for processing a workpiece according to the present embodiment, the workpiece is processed by the processing device. First, the workpiece will be described. FIG. 1 includes a perspective view schematically showing a workpiece 1.

[0020] The workpiece 1 is, for example, a roughly disc-shaped wafer made of Si, SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor materials. However, the workpiece 1 is not limited to these.

[0021] Workpieces such as disc-shaped wafers are formed, for example, by cutting a cylindrical ingot. By forming a disc-shaped wafer, arranging multiple devices in a matrix on the wafer surface, thinning the wafer, and dividing the wafer into individual devices, individual thin device chips can be obtained.

[0022] More specifically, multiple intersecting division lines (streets) 5 are set on the surface 1a of the workpiece 1, and devices 7 such as ICs, LSIs, LEDs, and optical sensors are formed in each region demarcated by the division lines 5. Subsequently, grinding and polishing the workpiece 1 from the back surface 1b allows the workpiece 1 to be thinned. Then, cutting or laser processing the workpiece 1 along the division lines 5 allows the workpiece 1 to be divided into individual device chips.

[0023] Thinning of the workpiece 1 can be performed using processing equipment such as grinding and polishing devices. Dividing of the workpiece 1 can be performed using processing equipment such as cutting devices or laser processing devices. A tape-shaped protective member 3 is attached in advance to the surface of the workpiece 1 opposite to the surface being processed by a protective member placement device. Figure 1 is a schematic perspective view showing how the protective member 3 is placed on the workpiece 1. In addition, various processing devices are used in each step of the process, such as cleaning the workpiece 1.

[0024] A processing device for processing a workpiece 1 generally comprises a holding table (chuck table) that holds the workpiece 1 to be processed by suction, and a processing unit that processes the workpiece 1 held by the holding table. Furthermore, the processing device comprises a loading mechanism (transportation unit) that loads the workpiece 1 into the holding table, and an unloading mechanism (transportation unit) that unloads the processed workpiece 1 from the holding table.

[0025] The following description will focus on a case where a wafer is processed as the workpiece 1, and a grinding device is used as the processing apparatus; however, this embodiment is not limited to this. Next, a grinding device will be described in detail as an example of a processing apparatus according to this embodiment.

[0026] Figure 2 is a schematic perspective view showing a processing device (grinding device) 2 and a workpiece 1. The processing device 2 includes a base 4 that supports each component. Cassette mounting tables 26a and 26b are fixed to the front end of the base 4. Cassettes 28a and 28b containing the workpiece 1 before grinding are placed on the cassette mounting tables 26a and 26b. The workpiece 1 is then pulled out of the cassettes 28a and 28b, processed by the processing device 2, and then placed back into the cassettes 28a and 28b.

[0027] A wafer transfer robot 30 is installed adjacent to the cassette mounting tables 26a and 26b on the base 4. The wafer transfer robot 30 unloads the workpiece 1 from the cassettes 28a and 28b placed on the cassette mounting tables 26a and 26b and transports the workpiece 1 to a positioning table 32 located adjacent to the wafer transfer robot 30 on the base 4.

[0028] The positioning table 32 has a plurality of positioning pins arranged in an annular shape. When the workpiece 1 is placed on the central mounting area of ​​the positioning table 32, the positioning table 32 moves each positioning pin radially inward in conjunction with each other to position the workpiece 1 at the intended position.

[0029] A loading arm 34 and a transport unit (unloading arm, unloading mechanism) 36 are provided adjacent to the positioning table 32 on the upper surface of the base 4. The workpiece 1, positioned at the predetermined position by the positioning table 32, is transported by the loading arm 34 to the holding table 8, which will be described next.

[0030] A disc-shaped turntable 6 is mounted on the central upper surface of the base 4 so as to be rotatable in a horizontal plane. Three holding tables (chuck tables) 8 are provided on the upper surface of the turntable 6, spaced 120 degrees apart from each other in the circumferential direction. Rotating the turntable 6 allows each of the holding tables 8 to move.

[0031] Figure 3 shows a schematic cross-sectional view of the holding table 8. The holding table 8 comprises a frame 42 with a recess formed on its upper surface, and a porous member 44 housed in the recess of the frame 42. The frame 42 has a passage 46 connecting the recess for housing the porous member 44 and the bottom surface of the frame 42.

[0032] A pipe 48 is connected to the end of a passage 46 that opens in the bottom surface of the frame 42. A switching valve 50, which consists of a solenoid valve or the like, is provided on the pipe 48. The switching valve 50 connects either the suction pipe or the supply pipe to the pipe 48. The switching valve 50 also disconnects the pipe 48 from the suction pipe and the supply pipe.

[0033] A suction source 52, such as a pump, is connected to the suction piping. A liquid supply source 54, which can supply liquids such as water to the supply piping, and a gas supply source 56, which can supply gases such as air and nitrogen gas to the supply piping are connected to the supply piping.

[0034] When the switching valve 50 is operated to connect the suction pipe and the pipe 48, the negative pressure generated at the suction source 52 is supplied to the porous member 44 through the pipe 48 and the passage 46. If the workpiece 1 has been placed on the porous member 44 beforehand, negative pressure is then applied to the workpiece 1 through the porous member 44, causing the workpiece 1 to be held in place by the holding table 8.

[0035] In other words, the holding table 8 holds the workpiece 1, which is placed on the holding surface 8a, by applying negative pressure generated by the suction source 52 through the porous member 44. That is, the upper surface of the holding table 8 becomes the holding surface 8a.

[0036] Furthermore, a rotational drive source such as a motor is connected to the bottom of the holding table 8, and the holding table 8 can rotate around a rotation axis 8b (see Figure 4) which is set to penetrate the holding surface 8a. The bottom of the holding table 8 is also supported by multiple support shafts (not shown), and one or more of these support shafts are extendable and retractable. By adjusting the length of these support shafts, the inclination of the holding surface 8a (the inclination of the rotation axis 8b) can be changed.

[0037] Returning to Figure 2, the explanation continues. The loading and unloading of the workpiece 1 to and from the holding table 8 is performed in the loading / unloading area of ​​the turntable 6. In the loading / unloading area, the workpiece 1 can be loaded into the holding table 8 by the loading arm (loading mechanism) 34, and the workpiece 1 can be unloaded from the holding table 8 by the transport unit (unloading arm, unloading mechanism) 36.

[0038] After loading the workpiece 1 onto the holding table 8 located in the loading / unloading area using the loading arm 34, the turntable 6 is rotated to move the holding table 8 to the rough grinding area, which will be described next.

[0039] On the rear upper surface of the base 4, outside the turntable 6, is a first processing unit (grinding unit) 10a which rough grinds the workpiece surface (back surface 1b) of the workpiece 1 held by a holding table 8 positioned in the rough grinding area. After the rough grinding of the workpiece 1 is performed by the first processing unit 10a, the turntable 6 is rotated to move the holding table 8 to the finish grinding area adjacent to the rough grinding area.

[0040] Outside the turntable 6 on the rear upper surface of the base 4, a second processing unit (grinding unit) 10b is positioned to perform finish grinding on the workpiece surface (back surface 1b) of the workpiece 1 held on a holding table 8 located in the finish grinding area. After the workpiece 1 is finished by the second processing unit 10b, the turntable 6 is rotated to return the holding table 8 to the loading / unloading area, and the workpiece 1 is unloaded from the holding table 8 by the transport unit 36.

[0041] A spinner cleaning device 38 for cleaning and spin-drying the ground workpiece 1 is provided near the transport unit 36 ​​on the upper surface of the base 4 and the wafer transport robot 30. The workpiece 1, which has been cleaned and dried by the spinner cleaning device 38, is then transported from the spinner cleaning device 38 by the wafer transport robot 30 and placed in cassettes 28a and 28b which are placed on cassette mounting tables 26a and 26b.

[0042] Columns 22a and 22b are erected at the rear of the base 4. A machining feed unit (grinding feed unit) 24a is provided on the front of column 22a to support the first machining unit 10a so that it can move along the vertical direction. A machining feed unit (grinding feed unit) 24b is provided on the front of column 22b to support the second machining unit 10b so that it can move along the vertical direction.

[0043] The first machining unit 10a, supported by the machining feed unit 24a, comprises a first spindle 14a extending vertically and a spindle motor 12a connected to the upper end of the first spindle 14a. The second machining unit 10b, supported by the machining feed unit 24b, comprises a second spindle 14b extending vertically and a spindle motor 12b connected to the upper end of the second spindle 14b. The orientation of each spindle 14a, 14b may be adjustable.

[0044] A disc-shaped wheel mount 16a is provided at the lower end of the first spindle 14a, and a first grinding wheel 18a is fixed to the lower surface of the wheel mount 16a. Multiple first grinding wheels 20a arranged in an annular shape are mounted on the lower surface of the first grinding wheel 18a.

[0045] A disc-shaped wheel mount 16b is provided at the lower end of the second spindle 14b, and a second grinding wheel 18b is fixed to the lower surface of the wheel mount 16b. Multiple second grinding wheels 20b arranged in an annular pattern are mounted on the lower surface of the second grinding wheel 18b.

[0046] When the spindle motor 12a is activated and the first spindle 14a is rotated, the first grinding wheel 18a rotates and the first grinding wheel 20a moves along the first annular track. Then, the machining feed unit 24a is activated to lower the first machining unit 10a and bring the first grinding wheel 20a into contact with the back surface 1b of the workpiece 1 held on the holding table 8, at which point the workpiece 1 is ground.

[0047] Furthermore, when the spindle motor 12b is activated and the second spindle 14b is rotated, the second grinding wheel 18b rotates and the second grinding wheel 20b moves along the second annular track. Then, when the machining feed unit 24b is activated and the second machining unit 10b is lowered, the second grinding wheel 20b comes into contact with the back surface 1b of the workpiece 1 held on the holding table 8, and the workpiece 1 is ground.

[0048] When grinding the workpiece 1 held on the holding table 8 with the processing units 10a and 10b, processing water (grinding water) consisting of water or the like is supplied to the back surface 1b of the workpiece 1, which is the surface to be ground. Processing debris (grinding debris) generated from the workpiece 1 and grinding wheels 20a and 20b during grinding is washed away by the processing water. In addition, processing heat generated in the workpiece 1, etc., during grinding is also removed by the processing water.

[0049] In grinding the workpiece 1 using the first processing unit 10a, the grinding feed by the processing feed unit 24a is performed at a relatively fast speed to roughly grind the workpiece 1. In rough grinding by the first processing unit 10a, large irregular shapes formed on the back surface 1b of the workpiece 1 are mainly removed.

[0050] In grinding the workpiece 1 using the second processing unit 10b, the grinding feed by the processing feed unit 24b is performed at a relatively low speed to finish grind the workpiece 1. In the finish grinding by the second processing unit 10b, mainly damaged layers and minute irregularities formed on the back surface 1b by rough grinding are removed.

[0051] The first grinding wheel 20a and the second grinding wheel 20b each contain abrasive grains made of diamond or the like, and a binder for dispersing and fixing the abrasive grains. Preferably, the second grinding wheel 20b, used for finish grinding, contains abrasive grains with a smaller particle size than the abrasive grains contained in the first grinding wheel 20a, used for rough grinding. In this case, the workpiece 1 can be roughly ground quickly with the first grinding wheel 20a, while the workpiece 1 can be finished with high quality using the second grinding wheel 20b.

[0052] A first thickness measuring unit 41a is provided near the first machining unit 10a on the upper surface of the base 4 to measure the thickness of the workpiece 1 being roughly ground by the first machining unit 10a. A second thickness measuring unit 41b is provided near the second machining unit 10b on the upper surface of the base 4 to measure the thickness of the workpiece 1 being finish ground by the second machining unit 10b.

[0053] The first thickness measuring unit 41a and the second thickness measuring unit 41b are, for example, contact-type thickness measuring units that come into contact with the back surface 1b of the workpiece 1. The contact-type thickness measuring unit comprises, for example, two probes extending above the holding table 8.

[0054] Each probe has a contact portion extending downward from the tip of a horizontally extending arm. One probe measures the height of the back surface 1b of the workpiece 1 by bringing the lower end of its contact portion into contact with the back surface 1b of the workpiece 1. The other probe measures the height of the holding surface 8a of the holding table 8 by bringing the lower end of its contact portion into contact with the holding surface 8a of the holding table 8.

[0055] The workpiece 1 is placed and held on the holding surface 8a of the holding table 8 via the protective member 3. Therefore, the contact-type thickness measuring unit can calculate the total thickness of the workpiece 1 and the protective member 3 from the difference between the height of the back surface 1b of the workpiece 1 and the height of the holding surface 8a of the holding table 8.

[0056] Alternatively, the first thickness measuring unit 41a and the second thickness measuring unit 41b are non-contact thickness measuring units that do not physically contact the back surface 1b of the workpiece 1. The non-contact thickness measuring unit measures the height of the back surface 1b of the workpiece 1 by sending ultrasonic waves or probe light to the back surface 1b from a measuring unit positioned directly above the back surface 1b of the workpiece 1, receiving the reflected ultrasonic waves, etc., at the measuring unit, and analyzing the ultrasonic waves, etc.

[0057] When grinding the workpiece 1, the holding table 8 is rotated around the rotation axis 8b, and the spindles 14a and 14b are rotated while the machining units 10a and 10b are lowered, bringing the grinding wheels 20a and 20b into contact with the back surface 1b of the workpiece 1. As a result, grinding progresses in an arc-shaped region from the outer circumference to the center of the workpiece 1, while the workpiece 1 on the holding table 8 rotates, and the entire surface of the workpiece 1 is ground.

[0058] Furthermore, the processing apparatus 2 includes a controller (control unit, control unit, control device) 40 that controls the processing apparatus 2. The controller 40 is connected to each component that makes up the processing apparatus 2 (wafer transfer robot 30, positioning table 32, loading arm 34, transfer unit 36, holding table 8, thickness measuring units 41a, 41b, processing units 10a, 10b, processing feed units 24a, 24b, etc.). The controller 40 operates the processing apparatus 2 by outputting control signals to each component of the processing apparatus 2.

[0059] For example, the controller 40 is comprised of a computer. Specifically, the controller 40 includes a processing unit that performs calculations and other processing necessary for the operation of the processing device 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the processing device 2. The processing unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0060] After the workpiece 1 is processed by the processing device 2, the suction holding of the workpiece 1 by the holding table 8 is released, and the workpiece 1 is suction-held by the transport unit 36 ​​(unloading arm, unloading mechanism), which is a type of transport device provided by the processing device, and the workpiece 1 is transported by the transport unit 36.

[0061] However, even after the suction holding of the workpiece 1 by the holding table 8 is released, the workpiece 1 remains tightly attached to the holding table 8, requiring considerable force to detach it from the holding table 8. However, the mechanical strength of the workpiece 1 is low, and the mechanical strength of the workpiece 1 thinned by the grinding device is particularly low. Therefore, if the transport unit 36 ​​forcibly detaches the workpiece 1 from the holding table 8, there is a risk that the workpiece 1 will be damaged.

[0062] Therefore, a method is known in which, when transporting the workpiece 1 from the holding table 8, liquid (water) is ejected from the holding surface 8a of the holding table 8 to separate the workpiece 1 from the holding surface 8a, while the transport unit 36 ​​moves the workpiece 1 from the holding table 8. However, even in this method, during the process of moving the workpiece 1 into the air from a state where the holding table 8 and the workpiece 1 are connected via liquid (water), a large force is applied to the workpiece 1 while the interfacial tension of the liquid (water) is released.

[0063] Therefore, in order to prevent damage to the workpiece 1, the transport unit (unloading mechanism) 36 had to carefully and slowly separate the workpiece 1 from the holding table 8 until the interfacial tension of the liquid (water) was relieved, which meant that the unloading of the workpiece 1 from the holding table 8 took a considerable amount of time. This sometimes contributed to a decrease in the processing efficiency of the workpiece in the processing device 2.

[0064] Therefore, in the processing apparatus 2 according to this embodiment, when the workpiece 1 is removed from the holding table 8, an operation is performed to remove the liquid (water) from the workpiece 1, etc. This allows the workpiece 1 to be removed from the holding table 8 without being significantly affected by the interfacial tension of the liquid (water). The following description of the processing apparatus 2 will focus on matters related to the operation of removing the liquid (water) from the workpiece 1 when the workpiece 1 is removed from the holding table 8.

[0065] First, the transport unit (unloading arm, unloading mechanism) 36 will be described in detail. Figure 5 shows a schematic cross-sectional view illustrating a part of the transport unit 36's configuration. The transport unit 36 ​​includes a plate-shaped transport section 60 that can contact the workpiece 1 and hold it by suction.

[0066] The conveying unit 60 is supported at the tip of the arm 36a (see Figure 2) via a damper 62. The conveying unit 60 includes, for example, a porous member 64 exposed on its lower surface and a suction passage 68 leading to the porous member 64. The suction passage 68 is connected to a suction source 72, such as a pump, via an electromagnetic valve 70, such as a solenoid valve. When the electromagnetic valve 70 is activated and the negative pressure generated by the suction source 72 is supplied to the porous member 64 through the suction passage 68, the conveying unit 60 can suck and hold the workpiece 1 that is in contact with its lower surface. That is, the lower surface of the conveying unit 60 becomes a holding surface 66.

[0067] For example, the transport unit 36 ​​can transport the workpiece 1 from the holding table 8 by holding (suction holding) the workpiece 1 held by the holding table 8 with the transport unit 60, and by rotating the arm 36a to move the transport unit 60.

[0068] Furthermore, the processing apparatus 2 includes a rotating part that rotates either the holding table 8 or the conveying section 60 of the conveying unit 36 ​​around a rotation axis 8b that passes through the holding surface 8a of the holding table 8. For example, the rotating part is a rotational drive source such as the motor described above that rotates the holding table 8. Alternatively, the conveying unit 36 ​​may include a rotational drive source, such as a motor, as its rotating part, which rotates the conveying section 60, located above the holding table 8, around a rotation axis that passes through the holding surface 8a of the holding table 8.

[0069] In the processing apparatus 2 according to this embodiment, the workpiece 1, which is held on the holding table 8 and processed by the processing units 10a and 10b, is held (suction held) by the transport section 60 of the transport unit 36, removed from the holding table 8, and transported.

[0070] At this point, the switching valve 50 is activated to disconnect the suction source 52 from the piping 48, and the liquid supply source 54 and the gas supply source 56 are connected to the piping 48. As a result, a fluid mixture of liquid (water) supplied from the liquid supply source 54 and gas (air) supplied from the gas supply source 56 passes through the piping 48. Consequently, the fluid is ejected from the holding surface 8a of the holding table 8.

[0071] Figure 8 shows the fluid 9 being ejected from the holding surface 8a of the holding table 8, causing the workpiece 1 to float away from the holding surface 8a of the holding table 8. When the fluid 9 is ejected from the holding surface 8a of the holding table 8, the workpiece 1 is detached from the holding surface 8a. In other words, the adhesion between the holding surface 8a and the workpiece 1 is broken.

[0072] At this time, by bringing the holding surface 66 of the conveying unit 60 into contact with the workpiece 1 in advance and holding the workpiece 1 by suction with the conveying unit 60, it is possible to prevent the workpiece 1 from moving as it floats up due to the fluid 9. When the workpiece 1 floats up due to the injection of the fluid 9, the damper 62 absorbs the lift of the conveying unit 60.

[0073] In the processing apparatus 2 according to this embodiment, after the fluid 9 is ejected from the holding surface 8a to release the contact between the holding surface 8a and the workpiece 1, the rotating part is activated to perform a rotational operation that rotates one or both of the holding table 8 and the conveying part 60. When the rotational operation is started, the ejection of the fluid 9 from the holding surface 8a may continue or may be stopped.

[0074] Figure 9 is a schematic cross-sectional view showing how rotation is performed by activating the rotating part to rotate the holding table 8. When rotation is performed, the fluid (water) 9 placed between the holding surface 8a and the workpiece 1 rotates along with the holding table 8 around the rotation axis 8b, causing centrifugal force to act on the fluid 9. As a result, the fluid 9 moves away from the rotation axis 8b on the holding surface 8a, reaches the outer edge of the holding surface 8a, and falls outside the holding table 8.

[0075] In other words, when rotation is performed, the fluid (water) 9 can be removed from between the holding surface 8a of the holding table 8 and the workpiece 1. Here, in the rotation, it is preferable to rotate the holding table 8 or the conveying section 60 of the conveying unit 36 ​​at a rotational speed of 10 to 1000 rpm. For example, in the rotation, the holding table 8 may rotate at a rotational speed of 60 rpm.

[0076] Furthermore, the rotational speed of the holding table 8 during rotational operation is preferably slower than the rotational speed of the holding table 8 (approximately 5000 rpm) when the workpiece 1 is processed (ground) by the processing units (grinding units) 10a and 10b. If the holding table 8 is rotated at an unnecessarily high speed, the force applied to the workpiece 1 due to the movement of the fluid 9 will increase, which may damage the workpiece 1.

[0077] In particular, the size of the holding surface 66 of the conveying section 60 of the conveying unit 36 ​​may be approximately the same as the back surface 1b of the smallest diameter workpiece 1 that can be assumed, so that it can suction and hold workpieces 1 of various sizes. Therefore, the size of the holding surface 66 of the conveying section 60 may be smaller than the diameter of the workpiece 1.

[0078] In other words, as shown in Figure 6, when the holding surface 66 contacts the back surface 1b of the workpiece 1, the outer periphery of the back surface 1b of the workpiece 1 may be exposed to the outside of the conveying section 60. That is, the outer periphery of the workpiece 1 may not be supported by the holding surface 66 of the conveying section 60 and may be susceptible to damage.

[0079] Therefore, it is preferable that the force exerted on the workpiece 1 by the movement of the fluid (water) 9 be as small as possible. Accordingly, it is preferable that the rotational speed of the holding table 8, etc., during rotational operation is slower than the rotational speed of the holding table 8 when the workpiece 1 is processed by the processing units 10a and 10b.

[0080] If the ejection of fluid 9 is simply stopped and the rotational movement is started to remove the fluid 9, the workpiece 1, which had been floating above the holding surface 8a, will come into contact with the holding surface 8a again. If the rotational movement of the holding table 8, etc. is started in this state, the workpiece 1 will be damaged. Therefore, before the rotational movement, it is preferable to move the transport section 60 of the transport unit 36 ​​away from the holding surface 8a of the holding table 8 using the moving unit.

[0081] More specifically, after the workpiece 1 floats up due to the start of fluid 9 ejection from the holding surface 8a, the transport unit 60 is raised to a degree that fluid 9 can exist between the workpiece 1 and the holding surface 8a, and then the rotational movement of the holding table 8, etc. is performed. The ejection of fluid 9 may be stopped after the transport unit 60 starts to rise, or it may be stopped after the rotational movement has started. Furthermore, it is preferable that the ejection of fluid 9 from the holding table 8 is stopped before the rotational movement is completed. However, the order of each operation is not limited to this.

[0082] When the rotational movement of the holding table 8, etc., is started and the fluid (water) 9 is removed from between the workpiece 1 and the holding surface 8a, the fluid 9 no longer acts as an interfacial tension on the workpiece 1. Therefore, when the transport unit 60 that holds the workpiece 1 is moved to move the workpiece 1 from the holding table 8, a large force is not applied to the workpiece 1.

[0083] In this case, unlike when transporting a workpiece 1 under the influence of the interfacial tension of fluid 9, there is no need to move the workpiece 1 from the holding table 8 at a low speed, and efficient removal of the workpiece 1 from the holding table 8 becomes possible. In other words, the efficiency of the workpiece 1 processing process in the processing apparatus 2 is not significantly reduced due to the removal of the workpiece 1 from the holding table 8.

[0084] In this embodiment of the processing apparatus 2, when the fluid 9 (liquid contained in the fluid 9) is removed by performing a rotational operation of the holding table 8, etc., it is not necessary to remove all of the fluid 9 present between the workpiece 1 and the holding surface 8a. That is, fluid 9 may remain between the holding surface 8a of the holding table 8 and the workpiece 1 after the rotational operation.

[0085] Compared to the case where fluid 9 remains throughout the entire area between the workpiece 1 and the holding surface 8a without rotational movement, even if only a portion of the fluid 9 is removed by rotational movement, the effect of interfacial tension acting on the workpiece 1 can be reduced. In other words, the effect of suppressing damage to the workpiece 1 when it is removed from the holding table 8 is achieved.

[0086] Next, as a method of using the processing apparatus 2 according to the embodiment described above, the procedure for processing the workpiece 1 with the processing apparatus 2 will be described in detail. The operation of the processing apparatus 2 described below is carried out by, for example, the controller (control unit) 40 controlling each component according to a program stored in a storage device or medium. Figure 11(A) is a flowchart showing the flow of each stage of the processing method for the workpiece 1.

[0087] In the processing method for processing the workpiece 1, first, the workpiece 1 is held on the holding surface 8a of the holding table 8 (holding step S10). The workpiece 1 is, for example, housed in cassettes 28a and 28b (see Figure 1) and transported to the processing apparatus 2. Then, the workpiece 1, which is pulled out from the cassettes 28a and 28b placed on the cassette mounting tables 26a and 26b by the wafer transport robot 30, is first transported to the positioning table 32. Then, its position is adjusted by the positioning table 32.

[0088] Then, the workpiece 1 is transported by the loading arm 34 onto the holding surface 8a of the holding table 8 positioned in the loading / unloading area. At this time, the back surface 1b of the workpiece 1 is exposed upwards, and the front surface 1a faces the holding surface 8a. Then, by operating the switching valve 50 and applying the negative pressure generated by the suction source 52 to the workpiece 1, the workpiece 1 is held in place by suction on the holding table 8. A protective member 3 may be provided in advance on the front surface 1a side of the workpiece 1. Figure 3 is a schematic cross-sectional view showing the workpiece 1 held by the holding table 8.

[0089] Next, the workpiece 1 held by the holding table 8 is processed (processing step S20). When processing (grinding) the workpiece 1, first, the turntable 6 is rotated to move the holding table 8 that holds the workpiece 1 to the rough grinding area below the first processing unit 10a, and the workpiece 1 is processed by the first processing unit 10a. After that, the holding table 8 that holds the workpiece 1 is moved to the finish grinding area below the second processing unit 10b, and the workpiece 1 is processed by the second processing unit 10b.

[0090] Figure 4 is a schematic cross-sectional view showing the workpiece 1 being processed by the processing units 10a and 10b. When processing the workpiece 1, the spindles 14a and 14b are rotated around the rotation axis 14c to rotate the grinding wheels 20a and 20b on an annular track, and the holding table 8 is rotated around the rotation axis 8b.

[0091] Then, the machining feed units 24a and 24b are activated to lower the machining units 10a and 10b, bringing the holding table 8 and grinding wheels 18a and 18b closer together. As a result, the bottom surfaces of the grinding wheels 20a and 20b come into contact with the back surface 1b of the workpiece 1, and the workpiece 1 is ground.

[0092] Furthermore, when the workpiece 1 is roughly ground by the first processing unit 10a, the downward speed of the first processing unit 10a should be greater than the processing speed of the second processing unit 10b when the workpiece 1 is finish ground by the second processing unit 10b. Also, when grinding the workpiece 1, the thickness of the workpiece 1 is monitored using the thickness measuring units 41a and 41b. When the workpiece 1 has been ground to a predetermined thickness, the downward movement of the processing units 10a and 10b is stopped, and grinding is terminated.

[0093] After the machining (rough grinding and finish grinding) of the workpiece 1 is completed, the turntable 6 is rotated to move the holding table 8 to the loading / unloading area. Then, the machined workpiece 1 held by the holding table 8 is held by the transport section 60 of the transport unit (unloading arm, unloading mechanism) 36, and the workpiece 1 is removed from the holding table 8 and transported (transport step S30).

[0094] The following describes the transport operation of the workpiece 1 from the holding table 8 (transport step S30) using Figures 5 to 10. Figure 11(B) is a flowchart showing the flow of each stage of the transport operation of the workpiece 1.

[0095] During the transport operation, the transport unit 36's transport section 60 is moved above the holding table 8 that holds the processed workpiece 1 by suction. Figure 5 is a schematic cross-sectional view showing the processed workpiece 1, the holding table 8 that holds the workpiece 1, and the transport section 60 positioned above the holding table 8.

[0096] Next, the conveying unit 60 is lowered so that its holding surface 66 contacts the back surface 1b of the workpiece 1, and the solenoid valve 70 is activated to supply negative pressure generated by the suction source 72 to the holding surface 66, thereby holding the workpiece 1 by suction with the conveying unit 36. The impact generated when the conveying unit 60 contacts the workpiece 1 is mitigated by the damper 62. Figure 6 is a schematic cross-sectional view showing the workpiece 1 and the like held by the conveying unit 60 by suction.

[0097] Subsequently, the switching valve 50 is operated to disconnect the suction source 52 from the piping 48, and the suction holding of the workpiece 1 by the holding table 8 is released. Figure 7 is a schematic cross-sectional view showing the workpiece 1 and other components when the suction holding of the workpiece 1 is released.

[0098] In the process of transporting the workpiece 1 from the holding table 8, a fluid containing liquid (water) (a mixture of water and air) 9 is then ejected from the holding surface 8a of the holding table 8 (S31). This causes the workpiece 1 to float away from the holding table 8. Figure 8 is a schematic cross-sectional view showing the workpiece 1 that has floated away from the holding surface 8a due to the ejection of the fluid 9.

[0099] Furthermore, after ejecting the fluid 9 to detach the workpiece 1 from the holding surface 8a, before performing the rotational operation described below, the transport unit 36's transport section 60 may be moved away from the holding surface 8a of the holding table 8. For example, the transport section 60 may be raised at a speed of 5 mm / second by an amount of 2 mm or more (e.g., 5 mm).

[0100] Next, a rotational operation is performed (S32). In the rotational operation, one or both of the holding table 8 and the conveying unit 60 are rotated around a rotation axis 8b that passes through the holding surface 8a of the holding table 8. Figure 9 is a schematic cross-sectional view showing how the fluid (water) 9 is removed by rotating the holding table 8. In Figure 9, the case in which the holding table 8 is rotated is shown as an example, but the conveying unit 60 may rotate instead of the holding table 8, or both the conveying unit 60 and the holding table 8 may rotate.

[0101] During rotation, centrifugal force is applied to the fluid (water) 9 remaining between the holding surface 8a of the holding table 8 and the workpiece 1 to expel it to the outside of the holding table 8. During rotation, it is preferable that the holding table 8 etc. rotate at a rotational speed of 10 rpm to 1000 rpm, that is, it is preferable that it rotates at a rotational speed slower than the rotational speed of the holding table 8 when the workpiece 1 is being processed by the processing units 10a and 10b. For example, the holding table 8 etc. rotates at a rotational speed of 60 rpm.

[0102] The rotational movement is performed while or after ejecting a fluid 9 containing liquid from the holding surface 8a of the holding table 8. When the rotational movement is performed while ejecting the fluid 9 from the holding surface 8a, it is preferable that the rotational movement be terminated after the ejection of the fluid 9 is stopped. Furthermore, during the rotational movement, it is not necessary to remove all of the fluid (water) 9 present between the holding surface 8a and the workpiece 1; some of the fluid 9 may remain between the holding surface 8a and the workpiece 1.

[0103] During or after the rotational operation (S32), the conveying unit 60 that holds the workpiece 1 by suction is moved away from the holding table 8 (S33). In other words, the workpiece 1 is conveyed away from the holding table 8. Figure 10 is a schematic cross-sectional view showing the workpiece 1 being conveyed by the conveying unit (unloading arm) 36.

[0104] By performing a rotational motion to remove at least a portion of the fluid 9 from between the holding surface 8a and the workpiece 1, the force (interface tension) exerted on the workpiece 1 by the fluid 9 when the workpiece 1 is raised becomes relatively small. Therefore, damage caused by this force is less likely to occur to the workpiece 1. Consequently, there is no need to carefully move the transport unit 60 at a low speed when transporting the workpiece 1 from the holding table 8, meaning that the transport operation of the workpiece 1 can be performed at high speed.

[0105] More specifically, conventionally, when removing the workpiece 1 from the holding table 8 without rotation, it was necessary to raise the transport unit 60 by about 10 to 15 mm at a speed of 1.5 mm / sec or less, and then move the transport unit 60 at a speed of about 5 mm / sec. This is to prevent the workpiece 1 from being damaged by the large surface tension of the fluid (water) 9 acting on it.

[0106] In contrast, in the processing apparatus 2 according to this embodiment, when transporting the workpiece 1 from the holding table 8, for example, the transport unit 60 can be raised by an amount of 2 mm or more (e.g., 5 mm) at a speed of 5 mm / sec before the rotational operation is completed, and the transport unit 60 can be raised at a speed of 50 mm / sec after the rotational operation. Alternatively, the transport operation can be performed by moving the transport unit 60 horizontally. As a result, the speed of the series of processing steps, in which multiple workpieces 1 are brought into the processing apparatus 2, processed, and then transported out, can be increased, and the processing efficiency of the workpieces 1 in the processing apparatus 2 can be improved.

[0107] Furthermore, in conventional processing apparatuses, the ejection of fluid 9 from the holding surface 8a of the holding table 8 could not be stopped until the transport unit 60 that suctions and holds the workpiece 1 moved far away from the holding table 8. On the other hand, in the processing apparatus 2 according to this embodiment, the ejection of fluid 9 can be stopped before the rotational operation is completed, thus reducing the amount of fluid 9 used.

[0108] It should be noted that the present invention is not limited to the embodiments described above and can be implemented with various modifications. For example, in the above embodiments, the processing device 2 was described using the case where the processing device 2 is a grinding device as an example, but the processing device 2 is not limited to a grinding device. For example, the processing device 2 according to one aspect of the present invention may be a grinding device for polishing the workpiece 1, a cutting device for cutting the workpiece 1 with a cutting blade equipped with an annular grinding wheel, a cleaning device for cleaning the workpiece 1, or a processing device for performing other processing on the workpiece 1.

[0109] Furthermore, although the above embodiment described a case where the fluid 9 is a mixed fluid of liquid (water, etc.) and gas (air, etc.), the present invention is not limited to this. That is, the fluid 9 may consist of liquid and may not contain gas. In this case, the processing apparatus 2 does not need to be equipped with a gas supply source 56.

[0110] Furthermore, although the above embodiment described a case in which a mixed fluid of liquid and gas is ejected from the holding surface 8a as fluid 9, the composition of fluid 9 may change thereafter. More specifically, the liquid (water) and gas (air) may separate and the gas may be released from fluid 9, or the gas may be removed from fluid 9 when it is removed by rotational motion.

[0111] The structures, methods, etc., according to the above embodiments can be modified as appropriate and implemented without departing from the scope of the object of the present invention. [Explanation of Symbols]

[0112] 1 Workpiece 1a surface 1b back side 3. Protective component Planned division lines (5 divisions) 7 devices 9 fluid 2 Processing equipment 4 base 6 Turntables 8. Holding Table 8a Holding surface 8b Rotation axis 10a, 10b Processing Unit 12a, 12b Spindle Motor 14a, 14b spindles 14c rotation axis 16a, 16b Wheel Mount 18a, 18b Grinding Wheel 20a, 20b grinding wheels 22a, 22b Column 24a, 24b Machining feed unit 26a, 26b Cassette mounting tray 28a, 28b Cassette 30 Wafer handling robots 32 Positioning Table 34 Loading Arms 36. Transport Unit (Unloading Arm) 36a Arm 38 Spinner cleaning device 40 controllers 41a, 41b Thickness measuring unit 42 Frame 44 Porous material 46 aisles 48 Piping 50 Switching valve 52 Suction source 54 Liquid Source 56 Gas supply source 60 Conveying section 62 dampers 64 Porous material 66 Holding surface 68 Suction channel 70 Solenoid valve 72 Suction source

Claims

1. A processing device for processing a workpiece, A holding table that holds the workpiece on a holding surface and can eject a fluid containing liquid from the holding surface, A processing unit for processing the workpiece held on the holding table, A transport unit that holds the workpiece held on the holding table in a transport unit and transports the workpiece from the holding table, The holding table and the transport unit, and a rotating unit that rotates one or both of them around a rotation axis passing through the holding surface of the holding table, A processing apparatus characterized in that, when a workpiece held on the holding table is held by the conveying unit and removed from the holding table for transport, the fluid is ejected from the holding surface of the holding table, or after ejection, the rotating part is operated to rotate one or both of the holding table and the conveying unit.

2. The system further includes a moving unit for moving the transport unit, The processing apparatus according to claim 1, characterized in that, prior to the rotational operation, the moving unit moves the conveying portion of the conveying unit away from the holding surface of the holding table.

3. A processing method for processing a workpiece, The workpiece is held on the holding surface of the holding table, The workpiece held on the holding table is processed by the processing unit, The process involves holding the processed workpiece, which has been held on the holding table, in the transport section of the transport unit, removing the workpiece from the holding table, and transporting it. A processing method characterized in that, in conveying the material, a fluid containing liquid is ejected from the holding surface of the holding table, or after the fluid has been ejected, and then a rotational operation is performed in which one or both of the holding table and the conveying unit are rotated around a rotation axis passing through the holding surface of the holding table.

4. The processing method according to claim 3, characterized in that, before the rotational operation, the conveying part of the conveying unit is moved away from the holding surface of the holding table.

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