Work holding device

Abstract

To provide a work holding device capable of stably performing suction and holding by correcting distortion or warpage of a dicing frame.SOLUTION: Provided is a device for holding a wafer W that is adhered to a dicing frame 11 via a dicing tape 12. The device comprises: a chuck table 14 including a chuck section 15 capable of sucking and holding the wafer W and a storage section 16 which is recessed in an outer periphery of the chuck section 15; and a chuck plate 18 in which a suction hole 18e opened on a top face 18d is formed and which is disposed in the storage section 16 and capable of sucking and holding the dicing frame 11. The suction hole 18e communicates with a sealed space 27 enclosed by the chuck table 14, the dicing frame 11 and the dicing tape 12 and when a negative pressure is supplied into the sealed space 27, a connection region 12a where the dicing frame 11 and the wafer W are connected in the dicing tape 12 approaches the chuck table 14.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a workpiece holding device that holds a workpiece such as a wafer attached to a dicing frame via a dicing tape in, for example, a semiconductor device manufacturing process. [Background technology]

[0002] In the manufacturing process of semiconductor devices, a grinding machine is used to grind a wafer to thin it. The grinding machine includes a chuck table that holds the wafer by suction, and a grinding means having a grinding wheel that grinds the wafer held by suction on the chuck table.

[0003] Furthermore, when a wafer is ground with a grinding wheel, if the wafer is warped, the wafer may not be held in the desired state even if the wafer is suction-held on a chuck table.

[0004] Therefore, a conventional method for transporting and setting a wafer involves attaching a dicing tape to a dicing frame with an opening in the center, preparing a work unit that allows one side of the wafer to be attached to the dicing tape exposed from the opening in the dicing frame, and transporting the wafer to a chuck table with the wafer set on the work unit (for example, Patent Document 1).

[0005] Meanwhile, a holding device that holds a work unit to which a wafer is attached is known, which uses a chuck table and has a wafer holding section in the center that holds the wafer by suction via a dicing tape, and a frame holding section that holds a dicing frame by suction around the outer periphery of the wafer holding section (also see Patent Document 1). The holding device in Patent Document 1 holds the wafer by suction with the wafer holding section of the chuck table, and also lowers the dicing frame, which is disposed on the wafer holding section of the chuck table, to a position where the top surface of the dicing frame is lower than the height position of the top surface of the finished wafer, and holds it by suction on the chuck table in that lowered position.

[0006] In the holding device described in Patent Document 1, a suction port (second suction port) provided in the wafer holding portion of the chuck table and a suction port (first suction port) also provided in the chuck table corresponding to the space between the wafer and the dicing frame suck out air, and the dicing tape is held by suction on the chuck table. However, if the dicing frame has a small plate thickness and low rigidity, and the dicing frame is distorted or warped due to the tension of the dicing tape, the dicing tape may also warp due to the warping of the dicing frame, and the dicing tape may not be able to be held by suction.

[0007] Therefore, there is a work holding device that is structured so that the dicing frame of the work unit together with the dicing tape is forcibly sucked into the frame holding section and held there during grinding processing. For example, structures such as those shown in Figures 9 and 10 are known.

[0008] The workpiece holding device 100 shown in Figures 9 and 10 includes a chuck table 110, a chuck plate 120, and a workpiece unit 130 shown in Figure 10. Note that Figure 9 shows the workpiece holding device 100 in a state before the workpiece unit 130 is set on the chuck table 110, and the workpiece unit 130 has been removed. Therefore, Figure 9 is a perspective view showing the chuck table 110 and the chuck plate 120. Meanwhile, Figure 10 is an enlarged cross-sectional view of a main portion in a state in which the workpiece unit 130 is set on the chuck table 110.

[0009] 9 and 10, the work unit 130 includes a dicing frame 132 having an opening 131 in the center, and a dicing tape 133 attached to cover the opening 131 of the dicing frame 132, and a disk-shaped wafer W is attached as a workpiece to the dicing tape 133 exposed in the opening 131, integrating the wafer W, the dicing tape 133, and the dicing frame 132. The front surface of the wafer W is attached to the dicing tape 133, and the back surface serves as a grinding surface to be ground by a grinding wheel or the like.

[0010] The chuck table 110 includes a chuck portion 111 having a holding surface 111a similar in shape to the wafer W, and a ring-shaped storage portion 112 recessed in the outer periphery of the chuck portion 111. A ring-shaped chuck plate 120 having an outer diameter approximately equal to an outer inner circumferential surface 112b of the storage portion 112 is disposed on a bottom surface 112a of the storage portion 112.

[0011] Further, twelve suction holes 112d penetrating the storage section 112 from top to bottom are provided in the bottom surface 112a of the storage section 112 in a circumferential direction thereof in correspondence with the positions where the chuck plate 120 is disposed. Further, a plurality of drainage holes 112e, the other ends of which open to the outer circumferential surface of the chuck table 110 and which discharge cleaning liquid remaining in the storage section 112 during, for example, a rinsing process, are provided in the bottom surface 112a of the storage section 112 in a circumferential direction at positions outside the region of the inner peripheral surface 112c that does not overlap with the chuck plate 120.

[0012] Meanwhile, the chuck plate 120 arranged in the storage section 112 has twelve suction holes 120a formed therein corresponding to the suction holes 112d of the storage section 112. That is, the suction holes 120a of the chuck plate 120 arranged in the storage section 112 correspond to the suction holes 112d vertically in the storage section 112 and communicate with each other. A negative pressure source of a negative pressure supplying means (not shown) is connected to the suction holes 112d and suction holes 120a, and the dicing frame 132 arranged on the chuck plate 120 in the storage section 112 can be sucked and held on the chuck plate 120 via the dicing tape 133 by the negative pressure from the negative pressure source. FIG. 10(a) shows a state in which the chuck table 110 sucks and holds the work unit 130 together with the wafer W in this manner. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] JP 2015-88565 A Summary of the Invention [Problem to be solved by the invention]

[0014] However, in the work holding device shown in Figures 9 and 10(a), the wafer W is held by suction in the chuck portion 111, and the dicing frame 132 within the storage portion 112 is held by suction toward the bottom surface 112a of the storage portion 112 via the chuck plate 120. However, if the dicing frame 132 is warped or the like due to the tension of the dicing tape 133, the dicing frame 132 cannot be adsorbed and held by the chuck plate 120.

[0015] 9 and 10(a), a drain hole 112e is provided on the bottom surface 112a of the storage section 112 in the chuck table 110. Therefore, when the dicing frame 132 is sucked by the suction hole 120a, as shown in FIG. 10(b), for example, outside air enters the storage section 112 as a leak flow 121a through the drain hole 112e, and the leak flow 121a weakens the suction force by the negative pressure, so that the dicing frame 132 cannot be instantly pulled vertically onto the chuck plate 120 and sucked. In addition, since the dicing frame 132 cannot be instantly pulled vertically onto the chuck plate 120 and sucked, the outer peripheral surface of the dicing frame 132 is inclined with respect to the outer inner peripheral surface 112b of the storage section 112, and a gap is generated between the outer peripheral surface of the dicing frame 132 and the outer inner peripheral surface 112b of the storage section 112, which may cause the leak flow 121b. When the leak current 121a and the leak current 121b occur, a suction error of the dicing frame 132 occurs.

[0016] Therefore, a technical problem arises that needs to be solved in order to provide a work holding device that can correct the distortion or warping of the dicing frame and stably hold the work by suction, and the object of the present invention is to solve this problem. [Means for solving the problem]

[0017] The present invention has been proposed to achieve the above-mentioned object, and the invention described in claim 1 provides a work holding device that holds a workpiece affixed to a dicing frame via dicing tape, comprising: a chuck table having a chuck portion capable of adsorbing and holding the workpiece and a storage portion recessed in the outer periphery of the chuck portion; and a chuck plate having an suction hole opening to an upper surface, disposed within the storage portion, and capable of adsorbing and holding the dicing frame, the suction hole being connected to an enclosed space surrounded by the chuck table, the dicing frame, and the dicing tape, and when negative pressure is supplied to the enclosed space, a connection area of ​​the dicing tape connecting the dicing frame and the workpiece bends so as to approach the chuck table.

[0018] According to this configuration, the suction holes that supply negative pressure are connected to a sealed space surrounded by the chuck table, the dicing frame, and the dicing tape. Therefore, when negative pressure is supplied to the sealed space through the suction holes, the connection area of ​​the dicing tape that connects the dicing frame and the workpiece is bent so as to approach the chuck table, and the tension of the dicing tape is relaxed. Then, if the dicing frame is distorted or warped, the warping is corrected by relaxing the tension of the dicing tape, and the dicing frame is tightly attached to the chuck plate.

[0019] The invention described in claim 2 provides a work holding device in the configuration described in claim 1, wherein the opening of the suction hole is formed from a loading area of ​​the chuck plate where the dicing frame is placed to a non-loading area inside the loading area where the dicing frame is not placed.

[0020] According to this configuration, the openings of the suction holes are formed from the mounting area of ​​the chuck plate, where the dicing frame is mounted, to the non-mounting area, which is inside the mounting area, where the dicing frame is not mounted. Therefore, even if a dicing frame is mounted on the chuck plate, negative pressure can be stably supplied over a wide area of ​​the sealed space through the suction holes in the non-mounting area.

[0021] The invention as recited in claim 3 provides a workpiece holding device as recited in claim 1, wherein openings of the suction holes are formed in a mounting area of ​​the chuck plate on which the dicing frame is mounted.

[0022] According to this configuration, when negative pressure is supplied to the sealed space through the suction hole, the connection area of ​​the dicing tape that connects the dicing frame and the workpiece bends toward the chuck table, thereby relieving the tension in the dicing tape, thereby correcting any warping of the dicing frame and bringing the dicing frame into close contact with the chuck plate.

[0023] A fourth aspect of the present invention provides a workpiece holding device according to the first aspect, further comprising a chuck support loader capable of pressing the dicing frame toward the chuck plate.

[0024] According to this configuration, the dicing frame placed on the chuck plate is pressed toward the chuck plate by the chuck support loader, and negative pressure is supplied while the dicing frame is in close contact with the chuck plate, so that the dicing frame can be more reliably sucked and held against the chuck plate.

[0025] The invention described in claim 5 provides a work holding device in the configuration described in claim 4, wherein the chuck support loader presses the dicing frame toward the chuck plate when in an unheld state in which the dicing frame is not held by the chuck plate, and releases the pressure on the dicing frame when in a held state in which the dicing frame is held by the chuck plate.

[0026] According to this configuration, while the dicing frame transported onto the dicing plate is in an unheld state and not held by suction, the chuck support loader presses the dicing frame towards the chuck plate, and when the dicing frame is in a suction-held state, the pressure applied by the chuck support loader to the dicing frame is released, so that the dicing frame transported onto the dicing plate can be securely held against the chuck plate until it is held by suction to the dicing plate.

[0027] A sixth aspect of the present invention provides a workpiece holding device according to the first aspect, wherein the chuck plate is formed so as to cover a bottom surface of the storage portion.

[0028] According to this configuration, since the chuck plate is formed to cover the bottom surface of the storage section, the chuck plate can be placed in a stable state by being in close contact with the bottom surface of the storage section, and therefore the dicing plate held on the chuck plate can also be held in a stable state in the storage section via the chuck plate. Effect of the Invention

[0029] According to the present invention, the suction holes for supplying negative pressure are provided in communication with the sealed space surrounded by the chuck table, the dicing frame, and the dicing tape. Therefore, when negative pressure is supplied to the sealed space through the suction holes, the connection area of ​​the dicing tape that connects the dicing frame and the workpiece bends so as to approach the chuck table, thereby relieving the tension of the dicing tape, thereby correcting any warping of the dicing frame and bringing the dicing frame into close contact with the chuck plate. [Brief description of the drawings]

[0030] [Figure 1] 1 is a perspective view showing a schematic configuration of a work holding device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic external perspective view of a chuck table in the workpiece holding device, showing a state in which a chuck plate is disposed. [Diagram 3] 2A and 2B are diagrams showing a schematic configuration of a chuck support loader in the workpiece holding device, in which (a) is a perspective view of the chuck support loader, and (b) is a schematic enlarged sectional view taken along line AA in (a). [Figure 4] FIG. 1 shows an example of the flow of a work process for grinding a workpiece using the above-mentioned work holding device, in which (a) shows the state immediately after a work unit with a workpiece attached to it has been transported onto the chuck table, (b) shows the state in which the dicing frame of the work unit is pressed against the chuck plate, (c) shows the state in which the work unit with a workpiece attached is adsorbed and held on the chuck table, and (d) shows the state in which the workpiece adsorbed and held on the chuck table is ground with a grinding wheel. [Diagram 5] FIG. 13 is a diagram explaining the bending process in the connection area of ​​the dicing tape when negative pressure is supplied from the suction port, where (a) is a diagram showing the state before negative pressure is supplied, (b) is a diagram showing the state immediately after the supply of negative pressure begins, and (c) is a diagram showing the state when the connection area has been sufficiently pulled to hold the work unit in place. [Figure 6] FIG. 2 is a perspective view showing a state in which a partially deformed chuck plate is disposed on a chuck table in the workpiece holding device. [Figure 7] FIG. 13 is a diagram explaining the bending process in the connection area of ​​the dicing tape when negative pressure is supplied from the suction port using the deformed chuck plate as described above, where (a) shows the state before negative pressure is supplied, (b) shows the state immediately after the supply of negative pressure begins, and (c) shows the state when the connection area has been sufficiently pulled to hold the work unit in place. [Figure 8] 6 is an enlarged cross-sectional view of a main portion showing a further modified example of the work holding device shown in FIGS. 1 to 5. FIG. [Figure 9] FIG. 1 is a schematic external perspective view of a chuck table with a chuck plate disposed thereon, showing an example of a conventional workpiece holding device. [Figure 10] 10A and 10B are enlarged cross-sectional views of the essential parts showing a state in which a work unit with a work attached is suction-held on the chuck table shown in FIG. 9, where (a) is a diagram before the problem is pointed out, and (b) is a diagram explaining the conventional problem. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] In order to achieve the object of providing a work holding device that can correct distortion or warping of a dicing frame and stably hold a work by suction, the present invention provides a work holding device that holds a work affixed to a dicing frame via dicing tape, the work holding device comprising: a chuck table having a chuck portion capable of suction-holding the work and a storage portion recessed in the outer periphery of the chuck portion; and a chuck plate having suction holes opening to the upper surface, disposed within the storage portion and capable of suction-holding the dicing frame, the suction holes being connected to an enclosed space surrounded by the chuck table, the dicing frame and the dicing tape, and when negative pressure is supplied to the enclosed space, the connection area of ​​the dicing tape connecting the dicing frame and the work bends so as to approach the chuck table. EXAMPLES

[0032] An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the following embodiment, when the number, value, amount, range, etc. of components are mentioned, the number is not limited to the specific number, and may be more or less than the specific number, unless otherwise specified or when it is clearly limited to a specific number in principle.

[0033] In addition, when referring to the shape or positional relationship of components, etc., this includes things that are substantially similar or approximate to those shapes, etc., unless otherwise specified or considered to be clearly different in principle.

[0034] In addition, the drawings may exaggerate characteristic parts to make the features easier to understand, and the dimensional ratios of the components may not be the same as the actual ones. In addition, in cross-sectional views, hatching of some components may be omitted to make the cross-sectional structure of the components easier to understand.

[0035] In the following description, the expressions indicating directions such as up, down, left, right, etc. are not absolute, but are appropriate when each part of the work holding device of the present invention is in the posture depicted, but if the posture is changed, the interpretation should be changed accordingly. Also, the same elements are given the same symbols throughout the description of the embodiment.

[0036] 1 is a perspective view showing a schematic configuration of a work holding device 10 according to the present invention, and shows as an example a case in which a wafer W is used as a work in a semiconductor device manufacturing process, and the work holding device 10 is used to perform a grinding process to thin the wafer W. In addition, as a method for transporting and setting the wafer W, as an example, a case is shown in which a dicing tape 12 is attached to a dicing frame 11 having an opening 11a in the center, a work unit 13 is prepared so that one side of the wafer W can be attached to the dicing tape 12 exposed from the opening of the dicing frame 11, the wafer W is set on the work unit 13, and the wafer W is transported together with the work unit 13 toward a chuck table 14.

[0037] The chuck table 14 is provided with a chuck portion 15 having a holding surface 15a similar to the wafer W, capable of holding the wafer W by suction through the dicing tape 12 under negative pressure, and a frame holding means 17 having an annular storage portion 16 recessed in the outer periphery of the chuck portion 15. The chuck portion 15 is connected to a negative pressure supplying means (not shown) so that negative pressure can be supplied to the holding surface 15a from the negative pressure supplying means. Meanwhile, the uppermost portion of the frame holding means 17 is formed at a height position lower than the holding surface 15a of the chuck portion 15. In addition, an annular chuck plate 18 is disposed on the bottom surface 16a of the storage portion 16 in the frame holding means 17, the outer periphery of which is approximately equal to the outer inner periphery 16b of the storage portion 16 and the inner periphery of which is approximately equal to the inner inner periphery 16c of the storage portion 16.

[0038] Fig. 2 is a schematic external perspective view of the chuck table 14 with the chuck plate 18 disposed thereon. The configurations of the chuck table 14 and the chuck plate 18 will be further described with reference to Fig. 2 in addition to Fig. 1. A plurality of suction holes 16d penetrating vertically are formed in the bottom surface 16a of the storage section 16 in the chuck table 14 and scattered in the circumferential direction of the storage section 16. One end of the suction holes 16d opens to the bottom surface 16a. Meanwhile, the other end of the suction holes 16d is led to the lower surface of the chuck table 14 and connected to a negative pressure supplying means (not shown), so that a negative pressure can be supplied into the storage section 16 from the negative pressure supplying means.

[0039] The chuck plate 18 is substantially the same as the annular shape of the storage section 16 in the chuck table 14, and is disposed on the bottom surface 16a of the storage section 16 with its lower surface 18a substantially in close contact with the bottom surface 16a, its outer peripheral surface 18b in contact with the outer inner peripheral surface 16b, and its inner peripheral surface 18c in contact with the inner inner peripheral surface. The chuck plate 18 is formed so that when the dicing frame 11 of the work unit 13 is placed on the chuck plate 18, the upper surface 11b of the dicing frame 11 is at a lower height position than the uppermost portion 17a of the frame holding means 17. The chuck plate 18 is formed with a plurality of suction holes 18e penetrating the upper surface 18d and the lower surface 18a, each corresponding to the suction holes 16d formed on the bottom surface 16a of the storage section 16. The chuck plate 18 is disposed in the storage section 16 with the suction holes 18e corresponding to the suction holes 16d of the storage section 16 in the up-down direction. This state is shown in Figures 1 and 2. Furthermore, the suction holes 18e and 16d are formed within the placement area of ​​the chuck plate 18 on which the dicing frame 11 is placed, that is, substantially directly below the dicing frame 11.

[0040] The transport means 19 includes a transport arm 20 and a gripping arm body 22 attached to the transport arm 20 via a shaft body 21 so as to be rotatable and movable in the vertical direction. The transport arm 20 moves the gripping arm body 22 from a predetermined position to a predetermined position, and the gripping arm body 22 grips the work unit 13 and transports the work unit 13 back and forth from the predetermined position to above the chuck table 14 by the movement of the transport arm 20.

[0041] The gripping arm body 22 is stacked vertically around the shaft body 21, with the shaft body 21 at the center, and has a chuck support arm 23 arranged on the upper side, and a chuck support loader 24 arranged below the chuck support arm 23.

[0042] The chuck support loader 24 is provided with an annular pad material 25 protruding toward the dicing frame 11 at its outer circumferential tip portion that can face the dicing frame 11. The pad material 25 can be moved horizontally in the up and down direction under the control of a lift control mechanism 24a provided in the chuck support loader 24, and by moving horizontally downward, the dicing frame 11 arranged on the chuck plate 18 in the storage section 16 is pressed substantially parallel to the upper surface 18d of the chuck plate 18, thereby making it possible to hold the dicing frame 11 in intimate contact with the chuck plate 18.

[0043] The chuck support arm 23 has four suction parts 26 arranged concentrically at its outer circumferential tip portion that can face the dicing frame 11. The suction parts 26 are connected to a negative pressure supplying means (not shown), and suction the dicing frame 11 to which the wafer W is attached at a predetermined position with negative pressure, grip the work unit 13 and transport it to above the chuck table 14, and then release the negative pressure so that the work unit 13 can be placed on the chuck table 14.

[0044] Figure 4 is a schematic operational diagram showing an example of the operating procedure of the work holding device 10 when grinding a wafer W using the work holding device 10, and Figure 5 is a partially enlarged cross-sectional view illustrating how, when negative pressure is supplied from a negative pressure supply means through suction holes 16d and 18e into the sealed space 27 surrounded by the chuck table 14, the dicing frame 11 and the dicing tape 12, the connection area 12a of the dicing tape 12 connecting the dicing frame 11 and the wafer W bends toward the chuck table 14, relieving the tension of the dicing tape 12, and when warping or the like occurs in the dicing frame 11, the warping or the like of the dicing frame 11 is corrected to be approximately flat.

[0045] The operation of the workpiece holding device 10 shown in Figures 1 to 3 will now be described with reference to Figures 4 and 5. First, as shown in Figure 1, a workpiece unit 13 is prepared in which the front surface of a wafer W is attached to a dicing tape 12 and the back surface of the wafer W faces upward as the surface to be ground.

[0046] Next, as shown by the arrow (A) in Figure 1, at a predetermined position, the suction portion 26 of the gripping arm body 22 of the transport means 19 adsorbs and holds the dicing frame 11 of the work unit 13 on which the wafer W is attached by negative pressure, and grips the work unit 13.

[0047] 1, the conveying means 19 conveys the work unit 13 to above the chuck table 14. Then, the wafer W is placed on the holding surface 15a of the chuck section 15 via the dicing tape 12, and the dicing frame 11 is placed at a position corresponding to the chuck plate 18 in the storage section 16. After the dicing frame 11 is placed on the chuck plate 18, the supply of negative pressure to the suction section 26 is stopped, and the suction holding of the work unit 13 by the suction section 26 is released, resulting in an unheld state (see FIG. 4(a)). In this state, the dicing frame 11 is not placed in close contact with the chuck plate 18.

[0048] Next, as shown in FIG. 4(b), the chuck support loader 24 in the gripping arm body 22 is lowered onto the work unit 13 together with the pad material 25. Then, the lift control mechanism 24a is driven so that the pad material 25 comes into contact with the dicing frame 11 and presses the dicing frame 11 against the chuck plate 18. When the dicing frame 11 is pressed against the chuck plate 18, a sealed space 27 is formed surrounded by the chuck table 14, the dicing frame 11, and the dicing tape 12. In the sealed space 27, the suction hole 18e connected to the negative pressure supply means and the suction hole 16d are in communication. Therefore, when the negative pressure supply means is operated, the sealed space 27 can be made negative pressure through the suction hole 16d and the suction hole 18e, and the holding surface 15a of the chuck portion 15 can be made negative pressure.

[0049] When the negative pressure is applied to the holding surface 15a of the chuck portion 15 by the negative pressure supplying means, the wafer W is attracted and held onto the holding surface 15a via the dicing tape 12.

[0050] On the other hand, on the side of the storage section 16, a negative pressure is gradually supplied into the sealed space 27 through the suction holes 16d and 18e by the negative pressure supply means via a small gap between the lower surface 11c of the dicing frame 11 and the upper surface 18d of the chuck plate 18. As the pressure inside the sealed space 27 becomes negative, the negative pressure acts on the connection area 12a of the dicing tape 12 connecting the dicing frame 11 and the wafer W, causing the connection area 12a to bend inward (toward the upper surface 18d of the chuck plate 18), as shown in FIG. 4(c) and FIG. 5(c). Then, in conjunction with the supply of negative pressure, the connection area 12a is sucked toward the storage section 16 and bends, and the tension acting on the dicing tape 12 in the radial direction is relieved, as shown in FIG. When the tension of the dicing tape 12 is too large relative to the rigidity of the dicing frame 11, causing distortion or warping of the dicing frame 11, the warping of the dicing frame 11 is corrected, and the dicing frame 11 is adsorbed and held substantially parallel to the upper surface 18d of the chuck plate 18. In this case, the workpiece holding device 10 of this embodiment does not have a drainage hole, which is provided in the conventional device, so that the negative pressure control in the sealed space 27 is performed well, and the deflection of the connection area 12a and the warping of the dicing frame 11 can be corrected and the dicing frame 11 can be adsorbed and held at the same time. When the dicing frame 11 is adsorbed and held on the upper surface 18d of the chuck plate 18, the pad material 25 is raised by the control of the lift control mechanism 24a and returns to a predetermined position away from the dicing frame 11.

[0051] Furthermore, when the suction holding state (adsorption holding) is reached, even after the pressure applied by the pad material 25 on the dicing frame 11 in the chuck support loader 24 is released, the work unit 13 continues to be adsorbed and held on the chuck table 14, and at the same time the wafer W can be adsorbed and held on the holding surface 15a of the chuck portion 15 via the dicing tape 12.

[0052] Once the wafer W is sucked and held on the holding surface 15a of the chuck portion 15, the gripping arm body 22 returns to a predetermined position, leaving the work unit 13 on the chuck table 14. Then, as shown by the arrow (C) in Fig. 1 and Fig. 4(d), a grinding wheel 30 having a grinding stone 31 attached to its underside is sent onto the holding surface 15a, and the rotating grinding stone 31 is pressed against the back surface of the wafer W to perform grinding.

[0053] When the grinding process by the grinding wheel 31 is completed, the grinding wheel 30 returns to a predetermined position together with the grinding wheel 31. The negative pressure supply by the negative pressure supply means also stops, and the negative pressure to the holding surface 15a of the chuck portion 15 disappears, and the negative pressure to the dicing frame 11 also disappears.

[0054] Next, the gripping arm body 22 moves again to above the chuck table 14. Then, the dicing frame 11 is sucked and held by the suction portion 26, and the gripping arm body 22 transports the ground wafer W together with the work unit 13 to a predetermined position. This completes the series of operations for the grinding process.

[0055] Therefore, according to the workpiece holding device 10 of this embodiment, the suction holes 18e of the chuck plate 18 (and the suction holes 16d of the storage section 16) which serve as openings are formed from the placement area of ​​the chuck plate 18 where the dicing frame 11 is placed, to the non-placement area, inside the placement area, where the dicing frame 11 is not placed. As a result, even if the dicing frame 11 is placed on the chuck plate 18, negative pressure can be supplied over a wide area of ​​the sealed space through the suction holes 18e in the non-placement area, and the adhesion function is not reduced.

[0056] In addition, the opening of suction hole 18e (suction hole 16d) is formed from the mounting area of ​​the chuck plate 18 where the dicing frame 11 is placed to a non-mounting area inside the mounting area where the dicing frame 11 is not placed, so that negative pressure can be smoothly supplied to the sealed space 27 by the negative pressure supply means.

[0057] The dicing frame 11 is also provided with a chuck support loader 24 provided with a pad material 25 capable of pressing the dicing frame 11 against the chuck plate 18. The dicing frame 11 placed on the chuck plate 18 is pressed against the chuck plate 18 by the pad material 25 in the chuck support loader 24, and negative pressure can be supplied while the dicing frame 11 is in close contact with the chuck plate 18, so that the dicing frame 11 can be reliably held by suction against the chuck plate 18.

[0058] Furthermore, the chuck support loader 24 presses the dicing frame 11 toward the chuck plate 18 when the dicing frame 11 is in an unheld state where it is not held by the chuck plate 18, and releases the pressure on the dicing frame 11 when the dicing frame 11 is in a held state where it is held by the chuck plate 18. This allows the dicing frame 11 to be securely held against the chuck plate 18 until the dicing frame 11 transported onto the chuck plate 18 is held by suction.

[0059] In this embodiment, a structure in which a plurality of suction holes 16d and a plurality of suction holes 18e are provided has been disclosed, but it is sufficient to provide at least one suction hole 16d and at least one suction hole 18e.

[0060] 6 and 7 show a modified example of the work holding device 10 according to the present invention. In the work holding device 10 shown in Figs. 1 to 5, a structure is disclosed in which the opening of the suction hole 18e (suction hole 16d) is provided at a position slightly removed from the mounting area of ​​the chuck plate 18 on which the dicing frame 11 is placed. In the structure of the work holding device 10 of this modified example, the opening of the suction hole 18e communicating with the suction hole 16d is provided within the mounting area of ​​the chuck plate 18 on which the dicing frame 11 is placed, and other configurations are the same as those in Figs. 1 to 5, so that the same components are given the same reference numerals and repeated explanations are omitted.

[0061] 6 is a schematic external oblique view of the chuck table 14 and chuck plate 18 when the chuck plate 18 is positioned, and FIG. 7 is a diagram explaining the bending process in the connection area of ​​the dicing tape when negative pressure is supplied from suction hole 18e communicating with suction hole 16d using the chuck plate 18 shown in FIG. 6, where (a) is a diagram showing the state before negative pressure is supplied, (b) is a diagram showing the state immediately after the supply of negative pressure begins, and (c) is a diagram showing the state when the connection area has been sufficiently pulled to hold the work unit 13 in a predetermined position.

[0062] 6 and 7, the chuck table 14 has substantially the same structure as the chuck table 14 shown in Fig. 2, and a plurality of suction holes 16d penetrating vertically are formed in the bottom surface 16a of the storage section 16 and scattered in the circumferential direction of the storage section 16. Note that in Figs. 6 and 7, the openings of suction holes 18e communicating with the suction holes 16d are provided in the mounting area of ​​the chuck plate 18 on which the dicing frame 11 is mounted.

[0063] The chuck plate 18 shown in Fig. 6 and Fig. 7 has a substantially annular shape of the storage section 16 in the chuck table 14, and is disposed on the bottom surface 16a of the storage section 16 with its lower surface 18a substantially in close contact with the bottom surface 16a, its outer peripheral surface 18b in contact with the outer inner peripheral surface 16b, and its inner peripheral surface 18c in contact with the inner inner peripheral surface. The chuck plate 18 is provided with a plurality of suction holes 18e penetrating the upper surface 18d and the lower surface 18a, each corresponding to the suction holes 16d provided in the bottom surface 16a of the storage section 16, and is provided with negative pressure supply grooves 18f in the upper surface 18d of the chuck plate 18, each communicating with the suction holes 18e. The negative pressure supply grooves 18f open to the upper surface 18d of the chuck plate 18, and are formed from the suction holes 18e to the outer peripheral surface of the chuck plate 18 that is in contact with the inner inner peripheral surface 16c of the storage section 16. In other words, the negative pressure supply groove 18f, which is extended from the opening of the suction hole 18e, is formed as an opening extending from the opening of the suction hole 18e, spanning from the placement area of ​​the chuck plate 18 where the dicing frame 11 is placed to a non-placement area inside the placement area where the dicing frame is not placed.

[0064] Next, the operation of the chuck plate 18 shown in FIG. 6 and FIG. 7 will be described in the order of FIG. 7(a) to FIG. 7(c). The work unit 13 to which the wafer W is attached is held by the suction portion 26 of the gripping arm body 22 and transported to above the chuck table 14, similar to the work holding device 10 shown in FIG. 1 to FIG. 5. Then, the wafer W is placed on the holding surface 15a of the chuck portion 15 via the dicing tape 12, and the dicing frame 11 is placed on the chuck plate 18 in the storage portion 16. In addition, the chuck support loader 24 in the gripping arm body 22 is lowered onto the work unit 13 together with the pad material 25, and as shown in FIG. 7(a), the pad material 25 presses the dicing frame 11 against the chuck plate 18. In addition, when the dicing frame 11 is pressed against the chuck plate 18, a sealed space 27 surrounded by the chuck table 14, the dicing frame 11, and the dicing tape 12 is formed. Suction holes 18e, 16d, and negative pressure supply groove 18f connected to the negative pressure supply means are in communication with each other in this sealed space 27. Therefore, when the negative pressure supply means is operated, negative pressure can be created in the sealed space 27 through the suction holes 16d, 18e, and negative pressure supply groove 18f, and negative pressure can also be created on the holding surface 15a of the chuck portion 15.

[0065] When the negative pressure is applied to the holding surface 15a of the chuck portion 15 by the negative pressure supplying means, the wafer W is attracted and held onto the holding surface 15a via the dicing tape 12.

[0066] On the other hand, on the side of the storage section 16, when a negative pressure is supplied into the sealed space 27 through the suction holes 16d, 18e, and the negative pressure supply groove 18f by the negative pressure supply means, the negative pressure acts to bend the connection area 12a of the dicing tape 12, which connects the dicing frame 11 and the wafer W, inward (toward the upper surface 18d of the chuck plate 18), as shown by the arrow 30a in FIG. 7(b). Then, as shown in FIG. 7(c), in conjunction with the supply of negative pressure, the connection area 12a is sucked toward the storage section 16 and bends, and the tension acting on the dicing tape 12 in the radial direction is relaxed. Then, when the tension of the dicing tape 12 is excessively large relative to the rigidity of the dicing frame 11 and the dicing frame 11 is distorted or warped, the warping or the like occurring in the dicing frame 11 is corrected, and the dicing frame 11 is suctioned and held substantially parallel to the upper surface 18d of the chuck plate 18. Even in this case, the work holding device 10 of this embodiment does not have the drainage holes that were provided in conventional devices, so that negative pressure control within the sealed space 27 can be performed effectively, and correction of deflection of the connection area 12a and warping of the dicing frame 11 and adsorption of the dicing frame 11 can be performed all at once.

[0067] Therefore, in the work holding device 10 shown as this modified example, the negative pressure supply groove 18f which is connected to the opening of the suction hole 18e, i.e., the negative pressure supply groove 18f which is the opening of the suction hole 16d and the suction hole 18e, is formed from the loading area of ​​the chuck plate 18 where the dicing frame 11 is placed, to the non-loading area where the dicing frame 11 is not placed, inside the loading area. Therefore, even if the dicing frame 11 is placed on the chuck plate 18, negative pressure can be supplied over a wide area to the sealed space 27 through the negative pressure supply groove 18f which is the opening of the suction hole 16d and the suction hole 18e in the non-loading area.

[0068] In this modified example, a structure has been disclosed in which a plurality of suction holes 16d and suction holes 18e are provided, and a plurality of negative pressure supply grooves 18f communicating with the suction holes 18e are provided in the chuck plate 18. However, it is sufficient to provide at least one or more of the suction holes 16d, suction holes 18e, and negative pressure supply grooves 18f.

[0069] 8, two suction holes 18e may be provided at a distance from each other in the radial direction of the chuck plate 18, with the opening of one suction hole 18e being provided in a mounting area of ​​the chuck plate 18 where the dicing frame 11 is placed, and the opening of the other suction hole 18e being provided in a non-mounting area, inside the mounting area of ​​the chuck plate 18, where the dicing frame 11 is not placed. This allows a stable supply of negative pressure to the sealed space 27 from the opening of the suction hole 18e provided in the non-mounting area, even if the dicing frame 11 is placed on the chuck plate 18.

[0070] Furthermore, the present invention can be modified in various ways without departing from the spirit of the present invention, and it is natural that the present invention covers such modifications. [Explanation of symbols]

[0071] 10: Work holding device 11: Dicing frame 12: Dicing tape 12a: Connection area 13: Work Unit 14: Chuck table 15: Chuck part 15a: Holding surface 16: Storage area 16d: Adsorption hole 17: Frame holding means 18: Chuck plate 18e: Adsorption hole 18f: Negative pressure supply groove 24: Chuck support loader 24a: Lift control mechanism 25: Pad material 27: Closed space

Claims

1. A workpiece holding device that holds a workpiece attached to a dicing frame via a dicing tape, a chuck table including a chuck portion capable of suction-holding the workpiece and a storage portion recessed in an outer periphery of the chuck portion; a chuck plate having an adsorption hole opening on an upper surface thereof, the chuck plate being disposed within the storage portion and capable of adsorbing and holding the dicing frame; Equipped with the suction hole is in communication with a sealed space surrounded by the chuck table, the dicing frame, and the dicing tape; When a negative pressure is supplied to the sealed space, a connection region of the dicing tape that connects the dicing frame and the workpiece is bent so as to approach the chuck table. A work holding device characterized by:

2. The work holding device according to claim 1, characterized in that the opening of the suction hole is formed from a placement area of ​​the chuck plate on which the dicing frame is placed to a non-placement area inside the placement area on which the dicing frame is not placed.

3. 2. The workpiece holding device according to claim 1, wherein the openings of the suction holes are formed in a placement area of ​​the chuck plate on which the dicing frame is placed.

4. 2. The workpiece holding device according to claim 1, further comprising a chuck support loader capable of pressing the dicing frame toward the chuck plate.

5. 5. The workpiece holding device according to claim 4, wherein the chuck support loader presses the dicing frame toward the chuck plate in an unheld state in which the dicing frame is not held by the chuck plate, and releases the pressure on the dicing frame in a held state in which the dicing frame is held by the chuck plate.

6. The workpiece holding device according to claim 1 , wherein the chuck plate is formed so as to cover a bottom surface of the storage portion.

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