Holding table

Abstract

To wash an upper surface of a support plate around a holding table by utilizing cooling water.SOLUTION: A holding table 6 includes: a holding portion 610 for holding a workpiece; a frame body 620 having a recessed portion 621 for accommodating the holding portion 610, and surrounding the holding portion 610; a cooling unit 630 that cools the holding table 6; and a cover 640 surrounding the frame body 620. The cooling unit 630 has: a water channel 631 communicating with a water source, formed inside the frame body 620, and supplying cooling water to the inner part of the frame body 620; and a discharge port 633 formed in one end of the water channel 631 and opening in a side wall 642 of the frame body 620. A cover 640 has the side wall 642 suspended at an angle in an outwardly spreading direction. A predetermined empty space 700 is formed between a lower end of the side wall 642 and a support plate. Cooling water discharged from the discharge port 633 collides with the cover 640, flows along the side wall 642, is supplied to an upper surface 510 of the support plate, and washes the upper surface 510 of the support plate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a holding table. [Background technology]

[0002] A polishing device for mirror-finishing the surface of a plate-shaped workpiece includes at least a chuck table for suction-holding the plate-shaped workpiece and a polishing means having a polishing pad for polishing the plate-shaped workpiece, and the surface of the plate-shaped workpiece is polished by the polishing pad. For example, Patent Document 1 discloses a chuck table provided with a cooling water channel that is supplied to the inside of the frame of the holding table. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-237200 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional processing devices, while a cleaning unit is provided to clean the holding surface of the holding table, a separate cleaning unit is not provided to clean the upper surface of the support plate that supports the holding table. Therefore, in conventional processing devices, when the upper surface of the support plate becomes dirty, cleaning work is required.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a holding table that can use cooling water to clean the upper surface of a support plate around the holding table. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a holding table of the present invention is a holding table that is installed so as to protrude from an upper surface of a support plate and holds a workpiece, and is equipped with: a holding portion that holds the workpiece; a frame body having a recess that houses the holding portion and surrounds the holding portion; a cooling unit that cools the holding table; and a cover that surrounds the frame body, wherein the cooling unit has a water channel that is connected to a water source and is formed inside the frame body and supplies cooling water to the inside of the frame body, and a discharge port that is formed at one end of the water channel and opens into a side wall of the frame body, and the cover has side walls that slope downward in a direction that widens outward, and a predetermined gap is formed between the lower ends of the side walls and the support plate, The cooling water supplied from the water source to the water channel flows toward the outlet while cooling the frame, The cooling water discharged from the outlet collides with the inner wall of the cover, flows along the side wall, and is supplied to the upper surface of the support plate, cleaning the upper surface of the support plate located outside the holding table.

[0007] In the holding table, the support plate may be a turntable that rotatably supports one or more holding tables. [Effects of the Invention]

[0008] The processing apparatus of the present invention has the advantage that the upper surface of the support plate around the holding table can be washed using cooling water. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a processing device including a holding table according to an embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of the configuration of the holding table shown in FIG. [Figure 3] 3 is an exploded perspective view of the holding table shown in FIG. 1. FIG. [Figure 4] 4 is an exploded perspective view showing the holding table shown in FIG. 1 from the lower side. [Figure 5] FIG. 5 is a schematic cross-sectional view showing an example of the configuration of a holding table according to a modified example of the embodiment. [Figure 6] FIG. 6 is an exploded perspective view of a holding table according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made without departing from the gist of the present invention. In each of the following embodiments, the same components are designated by the same reference numerals, and redundant explanations will be omitted.

[0011] In the embodiments described below, an XYZ Cartesian coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ Cartesian coordinate system. One direction within a horizontal plane is defined as the X-axis direction, the direction perpendicular to the X-axis direction within the horizontal plane is defined as the Y-axis direction, and the direction perpendicular to both the X-axis and Y-axis directions is defined as the Z-axis direction. The XY plane containing the X-axis and Y-axis is parallel to the horizontal plane. The Z-axis direction perpendicular to the XY plane is the vertical direction.

[0012] [Embodiment] A processing apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing an example of the configuration of a processing apparatus 1 including a holding table according to an embodiment.

[0013] In FIG. 1, a processing apparatus 1 according to the embodiment can grind an area corresponding to a device area on the back surface of a workpiece 200 (work) to form the thickness of the device area to a predetermined thickness.

[0014] In Fig. 1, a workpiece 200, which is an object to be ground by the processing apparatus 1, is configured to have, for example, a base material 201. The base material 201 is, for example, a disk-shaped silicon, and may be a wafer such as a disk-shaped semiconductor wafer or an optical device wafer. Devices may be formed in areas partitioned by a plurality of planned dividing lines formed in a grid pattern on one surface of the workpiece 200. An adhesive tape 205 is attached to one surface of the workpiece 200. The workpiece 200 includes, for example, a substrate.

[0015] The processing apparatus 1 includes, for example, a housing 2, a first processing means 3, a second processing means 4, for example, three holding tables 6 installed on a turntable 5, cassettes 7 and 8, an alignment means 9, a carry-in means 10, a carry-out means 11, a cleaning means 12, and a carry-in / out means 13. In this embodiment, the processing apparatus 1 is described as including two processing means, but the number of processing means is not limited to this. For example, the processing apparatus 1 may include three or more processing means. The operation of the processing apparatus 1 is controlled by a control unit or the like (not shown). In this embodiment, the turntable 5 is an example of a support plate.

[0016] The turntable 5 is a disk-shaped device mounted on the upper surface of the housing 2, rotatable in a horizontal plane, and driven to rotate at appropriate timing. On the turntable 5, for example, three holding tables 6 are arranged at equal intervals, for example, at a phase angle of 120 degrees. Each holding table 6 has a chuck table structure with a vacuum chuck on its upper surface, and holds the workpiece 200 placed on the flat holding surface by vacuum suction. During grinding, each holding table 6 is rotated in a horizontal plane by a rotation drive mechanism (not shown) about a rotation axis perpendicular to the holding surface. As the turntable 5 rotates, the holding table 6 is moved relatively between a loading / unloading position 101, a rough grinding position 102 facing the first processing means 3, and a finish grinding position 103 facing the second processing means 4.

[0017] The first processing means 3 has a first grinding wheel 3-1 having a first grinding surface facing the holding surface of the holding table 6 located at the rough grinding position B, a first spindle unit 3-2 that rotatably supports the first grinding wheel 3-1 with a first rotation axis that is a vertical axis perpendicular to the first grinding surface, and a first slide unit 3-3 that supports the first spindle unit 3-2 so that it can move back and forth in the axial direction of the first rotation axis. Here, the first grinding wheel 3-1 is one with coarse abrasive grains for rough grinding. That is, the first grinding wheel 3-1 having a first grinding surface detachably attached to the lower end of the first spindle portion 3-2 is rotated around the first rotation axis by the motor 3-4, and the first slide portion 3-3 is pressed into contact with the upper surface of the workpiece 200 held on the holding surface of the holding table 6 located at the rough grinding position 102, thereby performing a predetermined rough grinding process on the upper surface of the workpiece 200.

[0018] The second processing means 4 has a second grinding wheel 4-1 having a second grinding surface facing the holding surface of the holding table 6 located at the finish grinding position C, a second spindle unit 4-2 that rotatably supports the second grinding wheel 4-1 with a second rotation axis that is perpendicular to the second grinding surface, and a second slide unit 4-3 that supports the second spindle unit 4-2 so that it can move back and forth in the axial direction of the second rotation axis. Here, the second grinding wheel used is one with fine abrasive grains for finish grinding. That is, the second grinding wheel 4-1 having a second grinding surface detachably attached to the lower end of the second spindle portion 4-2 is rotated about the second rotation axis by the motor 4-4, and the second slide portion 4-3 is pressed into contact with the upper surface of the workpiece 200 held on the holding surface of the holding table 6 located at the finish grinding position C, thereby performing a predetermined finish grinding process on the upper surface of the workpiece 200. Although not shown, this second processing means 4 has a mechanism for setting the second rotation axis at an angle with respect to the rotation axis, similar to the first processing means 3 described above.

[0019] The first slide portion 3-3 and the second slide portion 4-3 of the first processing means 3 and the second processing means 4 are provided so as to be movable up and down by lifting and lowering means 15 and 16, respectively, and are configured so as to be able to grind and feed the first grinding wheel 3-1 and the second grinding wheel 4-1 relative to the upper surface of the workpiece 200 on the holding table 6. These lifting and lowering means 15 and 16 are mounted on movable blocks 17 and 18 provided on the upper surface of the housing 2. The movable blocks 17 and 18 are provided so as to be movable relative to the housing 2 by a moving mechanism (not shown) so that the first grinding wheel 3-1 and the second grinding wheel 4-1 can move forward and backward in the radial direction of the turntable 5 relative to the holding table 6, which is positioned at the rough grinding position 102 or the finish grinding position 103.

[0020] The cassettes 7 and 8 are containers each having a plurality of slots for the workpiece 200. One cassette 7 accommodates the workpiece 200 before grinding, and the other cassette 8 accommodates the workpiece 200 after grinding. The workpiece 200 is not particularly limited, but examples thereof include semiconductor wafers such as silicon wafers and GaAs; inorganic material substrates such as ceramic, glass, and sapphire (Al2O3)-based substrates; ductile materials such as plate-shaped metals and resins; and various processing materials that require in-plane flatness (TTV: Total Thickness Variation: the difference between the maximum and minimum height values ​​over the entire surface of the workpiece 200 measured in the thickness direction with the grinding surface of the workpiece 200 as the reference plane) on the order of microns to submicrons.

[0021] The positioning means 9 is a table on which the workpiece 200 removed from the cassette 7 is temporarily placed and whose center is aligned. The carry-in means 10 is made up of a carry-in arm having a suction pad and driven to rotate in a horizontal plane, and sucks and holds the workpiece 200 before grinding that has been aligned by the positioning means 9, and carries it onto the holding table 6 located at the carry-in / carry-out position 101. The carry-out means 11 is made up of a carry-in arm having a suction pad and driven to rotate in a horizontal plane, and sucks and holds the workpiece 200 after grinding that is held on the holding table 6 located at the carry-in / carry-out position 101, and carries it out to the cleaning means 12. The carry-in / carry-out means 13 is, for example, a robot pick equipped with a U-shaped hand, and sucks and holds the workpiece 200 with the U-shaped hand and carries it in. Specifically, the carry-in / out means 13 carries the workpiece 200 before grinding out from the cassette 7 to the alignment means 9, and carries the workpiece 200 after grinding out from the cleaning means 12 into the cassette 8. The cleaning means 12 cleans the workpiece 200 after grinding out, and removes contamination such as grinding chips adhering to the ground surface.

[0022] (Example of retention table configuration) An example of the holding table 6 according to the embodiment will be described. FIG. 2 is a cross-sectional schematic view showing an example of the configuration of the holding table 6 shown in FIG. 1. FIG. 3 is an exploded perspective view of the holding table 6 shown in FIG. 1. FIG. 4 is an exploded perspective view showing the holding table 6 shown in FIG. 1 from below. The multiple holding tables 6 shown in FIG. 1 have the same basic configuration. In the example shown in FIG. 2, one holding table 6 out of the multiple holding tables 6 is shown.

[0023] 2, the holding table 6 is provided on the turntable 5 (support plate) and is configured to be able to hold a workpiece 200, which is a substrate. The holding table 6 is provided so as to protrude from an upper surface 510 of the turntable 5 to the outside of the processing apparatus 1. The holding table 6 has a holding portion 610 that holds the workpiece 200 and a recess 621 that houses the holding portion 610, a frame 620 that surrounds the holding portion 610, a cooling unit 630 that cools the holding table 6, and a cover 640 that surrounds the frame 620.

[0024] 2 and 3, the holding portion 610 is a suction plate formed in a disk shape. The holding portion 610 is made of, for example, a porous holding member, and its upper surface serves as a holding surface 611 that holds the workpiece by suction. The holding portion 610 comes into contact with the lower surface of the workpiece 200 and holds the workpiece 200 with the upper surface of the workpiece 200 exposed.

[0025] The frame 620 has a recess 621 formed in the center thereof, the recess 621 having an inner diameter larger than the outer diameter of the holding portion 610. A suction path 605 is provided in the center of the recess 621, connecting the holding portion 610 to a suction source 650. The holding table 6 can be used by fitting the holding portion 610 into the recess 621 of the frame 620. A rotation shaft 622 to which a rotation unit 660 is connected is coupled to the frame 620. The rotation unit 660 is composed of a pulley 662 connected to a motor 661, a pulley 663 attached to the rotation shaft 622, and a belt 664 wound around the pulleys 662 and 663. The rotation unit 660 rotates the frame 620 together with the rotation shaft 622 by driving the pulley 662, which causes the belt 664 to drive the pulley 663.

[0026] The cooling unit 630 includes a water channel 631 formed inside the frame body 620 and supplying cooling water to the inside of the frame body 620, and a plurality of outlets 633 formed at one end of the water channel 631 and opening in a side wall 623 of the frame body 620. In this embodiment, a case where the number of the plurality of outlets 633 is four will be described, but the number of the plurality of outlets 633 may be other than four.

[0027] In the example shown in Fig. 4, the cooling unit 630 has at least four water channels 631 that extend radially from the center of the frame body 620 and do not communicate with the suction channel 605. The number of water channels 631 is not limited to four. The water channels 631 extend parallel to the holding portion 610 shown in Fig. 2 to near the center of the frame body 620, and extend downward (vertically) from near the center of the frame body 620. A supply port 632 that connects the water channels 631 to a water source 634 is formed at the other end of the water channels 631.

[0028] The multiple outlets 633 are formed at positions that divide the outer periphery of side wall 623 of frame body 620 into four equal parts, but they do not have to be equally spaced. Outlet ports 633 are formed as openings in side wall 623 at the end of water channel 631. Outlet ports 633 are openings that can discharge the cooling water from water channel 631 toward cover 640 on the outside of frame body 620.

[0029] 2 , in cooling unit 630, when water source 634 is activated, cooling water flows into supply port 632 and flows through water channel 631, thereby cooling frame 620 and also holding portion 610 in contact with frame 620. Cooling unit 630 discharges the cooling water in water channel 631 from discharge port 633.

[0030] The cover 640 is formed to prevent processing debris from adhering to the frame body 620 and the rotation unit 660. The cover 640 has a base 641 that surrounds the frame body 620 and side walls 642 that hang down at an incline in a direction that widens outward from the base 641. The direction that widens outward from the base 641 includes, for example, a direction that widens away from the frame body 620. The cover 640 is a tapered member made of, for example, a metal member, a synthetic resin, or the like, in which the base 641 and the side walls 642 are integrally formed. The cover 640 is a member that rotatably exposes the recessed portion 621 of the frame body 620 and covers the other portions of the frame body 620.

[0031] The base 641 is formed in the shape of a flat ring with an inner diameter larger than the outer diameter of the frame 620. The base 641 is positioned and fixed to the rotating frame 620 with a gap therebetween. The sidewall 642 is formed as an inclined surface that widens outward from the outer periphery of the base 641 and toward the upper surface 510 of the turntable 5. The sidewall 642 forms a predetermined gap 700 between the frame 620 and the upper surface 510 of the turntable 5. The gap 700 includes the space inside the sidewall 642. The gap 700 includes a space into which cooling water is discharged from the outlet 633 of the cooling unit 630. A fixing portion 643 that is parallel to the upper surface 510 of the turntable 5 is formed at the end of the sidewall 642.

[0032] The fixing portion 643 is fixed to the upper surface 510 of the turntable 5 by a fixing member 644. The fixing portion 643 is fixed at a position spaced apart from the upper surface 510 of the turntable 5 by the height of the fixing member 644, thereby forming a gap 700 between the fixing portion 643 and the upper surface 510 of the turntable 5. In other words, the gap 700 is a space through which the cooling water discharged from the outlet 633 of the cooling unit 630 can be discharged to the upper surface 510 of the turntable 5 outside the cover 640. In this embodiment, the fixing member 644 is fixed to the upper surface 510 of the turntable 5 by fixing the fixing portion 643 of the cover 640 to three or more different points in the circumferential direction of the fixing portion 643.

[0033] (Example of holding table operation) As shown in FIG. 2 , when the water source 634 is activated, cooling water 800 supplied from the water source 634 to the water channel 631 flows toward the outlet 633 while cooling the frame 620. The cooling water 800 discharged from the outlet 633 hits the inner wall of the cover 640, flows along the side wall 642, and is supplied to the upper surface 510 of the turntable 5, thereby cleaning the upper surface 510 of the turntable 5. As a result, when the cooling water 800 hits the upper surface 510 of the turntable 5, the cooling water 800 is supplied in a direction 810 away from the holding table 6, thereby cleaning the upper surface 510 of the turntable 5 around the holding table 6. The moving direction 810 is a direction away from the holding table 6. By discharging the cooling water 800 while the frame 620 is rotating, centrifugal force increases the momentum of the cooling water 800 as it hits the inner wall of the cover 640, and the cooling water 800 can be supplied all around the holding table 6. The holding table 6 can supply the cooling water 800 to a desired part around the holding table 6 in a concentrated manner by discharging the cooling water 800 while the rotation of the frame 620 is stopped.

[0034] As described above, the holding table 6 forms a cover 640 against which the cooling water 800 supplied to the inside of the frame 620 surrounding the holding portion 610 hits, and the side walls 642 of the cover 640 are inclined so as to widen outward. This allows the cooling water 800 that hits the inner surface (inner wall) of the side wall 642 of the cover 640 to flow along the inclination of the side wall 642 and clean the top surface 510 of the turntable 5 located outside the holding table 6. Because the top surface 510 of the turntable 5 inside the cover 640 is covered by the cover 640, it is less likely to get dirty than the top surface 510 of the turntable 5 outside the cover 640. If the side walls 642 were not inclined, the cooling water would fall into the cover 640 and would only clean the top surface 510 of the turntable 5 inside the cover 640. In the present invention, the holding table 6 has an inclined side wall 642 of the cover 640, so that the upper surface 510 of the turntable 5 outside the cover 640, on which processing debris is likely to accumulate, can be efficiently cleaned.

[0035] For example, if the holding table 6 discharges the cooling water 800 directly onto the turntable 5 without using the cover 640, the water may splash before reaching the top surface of the turntable 5, making it impossible to clean the targeted area. However, in the present invention, the holding table 6 causes the cooling water 800 to collide with the cover 640 and flow along the side wall 642, thereby preventing the cooling water 800 from splashing into the machining space and allowing the cooling water 800 to be efficiently supplied to the turntable 5.

[0036] For example, the turntable 5 of the processing device 1 may have a dirty upper surface 510 or dust thereon. The holding table 6 according to the embodiment can effectively use the cooling water 800 that cools the inside of the frame 620 to clean the upper surface 510 of the turntable 5 around the holding table 6, thereby simplifying the cleaning work of the turntable 5.

[0037] The processing apparatus 1 includes the holding table 6 according to the embodiment, and therefore does not need to include a separate cleaning unit for cleaning the turntable 5. This allows the processing apparatus 1 to clean the upper surface 510 of the turntable 5 by using the holding table 6 without using a dedicated cleaning unit.

[0038] In the embodiment, the holding table 6 is described as including the rotation unit 660, but is not limited to this. For example, when the holding table 6 is rotated by external power or when the holding table 6 is not rotated, the rotation unit 660 may be omitted from the configuration.

[0039] In the embodiment, the holding table 6 is described as having a support plate that is the turntable 5, but is not limited to this. For example, the support plate includes a housing of the processing device 1 that supports the holding table 6.

[0040] [Modification of the embodiment] The holding table 6 according to the above-described embodiment can be modified as follows. For example, when the holding table 6 is configured so that the cover 640 covers a wide area of ​​the upper surface 510 of the turntable 5, the distance between the frame 620 and the cover 640 may be increased. Therefore, if the cleaning effect is insufficient due to the increased distance between the frame 620 and the cover 640, the holding table 6 may be configured so that the discharge port 633 protrudes.

[0041] Fig. 5 is a cross-sectional schematic diagram showing an example of the configuration of a holding table 6 according to a modified embodiment. Fig. 6 is an exploded perspective view of the holding table 6 according to the modified embodiment. As shown in Fig. 5, the holding table 6 includes a holding portion 610, a frame 620, a cooling unit 630, and a cover 640. As shown in Figs. 5 and 6, the cooling unit 630 includes a water channel 631 and a plurality of outlets 633-1 formed at one end of the water channel 631 and opening into a side wall 623 of the frame 620.

[0042] Discharge outlet 633-1 is formed to protrude outward from side wall 623 of frame body 620. Discharge outlet 633-1 is connected to water channel 631 and is formed in a tubular shape extending from side wall 623 of frame body 620 to near the inner wall of cover 640. The length of discharge outlet 633-1 can be designed arbitrarily depending on, for example, the distance from the end of discharge outlet 633-1 to the inner wall of cover 640, the amount of cooling water to be discharged, etc. Although a case where discharge outlet 633-1 is provided perpendicular to side wall 623 of frame body 620 will be described, discharge outlet 633-1 may be configured to be inclined with respect to side wall 623.

[0043] Holding table 6 is configured so that outlet 633-1 protrudes from frame body 620, thereby allowing cooling water 800 to slam forcefully against the inner wall of cover 640. Holding table 6 has outlet 633-1 protruding, so that cooling water 800 does not scatter and lose momentum, allowing it to slam against the inner wall of cover 640 while relatively maintaining its momentum, thereby improving the cleaning effect.

[0044] Although the holding table 6 according to the embodiment has been described as being used in the processing device 1 for grinding, the processing device 1 is not limited to the above embodiment and can be modified in various ways without departing from the gist of the present invention. For example, the processing device 1 may be a cutting device other than a grinding device or a laser processing device. [Explanation of symbols]

[0045] 1 Processing equipment 3. First processing method 4 Second processing method 5. Turntable 6 Holding table 7. Cassette 8 cassettes 9 Alignment means 10. Means of transport 11 Export means 12 Cleaning methods 13 Carrying in / out means 510 Top surface 610 Holding part 620 Frame 621 recess 622 Rotation axis 623 Side wall 630 Cooling Unit 631 Waterway 632 Supply port 633 Outlet 633-1 Outlet 634 Water source 640 Cover 641 Base 642 Side wall 643 Fixed part 644 Fixing member 650 Suction source 660 Rotating Unit 661 Motor 662 Pulley 663 Pulley 664 Belt 700 gap 800 Cooling water

Claims

1. A holding table that is installed so as to protrude from the upper surface of the support plate and that holds the workpiece, a holding portion that holds the workpiece; a frame body having a recess for accommodating the holding portion and surrounding the holding portion; a cooling unit that cools the holding table; a cover surrounding the frame body, The cooling unit comprises: a water channel formed inside the frame and communicating with a water source, the water channel supplying cooling water to the inside of the frame; a discharge port formed at one end of the water channel and opening into a side wall of the frame body; The cover is having side walls that slope downward in an outwardly expanding direction, a predetermined gap is formed between the lower end of the side wall and the support plate; The cooling water supplied from the water source to the water passage flows toward the outlet while cooling the frame, and the cooling water discharged from the outlet collides with the inner wall of the cover and flows along the side wall, a holding table provided on the upper surface of the support plate to clean the upper surface of the support plate located outside the holding table;

2. The support plate is A turntable that rotatably supports one or more holding tables. The holding table according to claim 1 .

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