Work holding device

Abstract

To provide a workpiece holding device which can directly hold a warped workpiece and transport it.SOLUTION: A workpiece holding device includes: a base 72; a pair of suction pads 74 provided at the base 72 to suction the workpiece W; and a cylinder device 76 which changes a space between the pair of suction pads 74.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a workpiece transport device, and more particularly to a workpiece transport device provided in a processing device that processes a workpiece such as a semiconductor wafer. [Background technology]

[0002] A dicing machine is a machine that uses a blade that rotates at high speed to perform cutting processes such as cutting or grooving on a workpiece such as a semiconductor wafer having electronic components formed on its surface (see, for example, Patent Document 1).

[0003] Such a dicing machine has a cassette storage section, a work cutting section, a cleaning section, a work transport device, etc. in the machine body. The cassette storage section stores a cassette that stores multiple wafers, and the wafers stored in the cassette are pulled out one by one by the work transport device and transported to the work cutting section. In this work processing section, the wafers are cut into dices by a blade, and the wafers that have been cut are transported to the cleaning section by the work transport device, and are returned to the cassette by the work transport device after cleaning.

[0004] Patent Document 2 discloses a workpiece transport device (transport mechanism) provided in a dicing device. This workpiece transport device transports a wafer attached to a protective tape, and has multiple suction pads that adsorb the upper surface of a support frame on which the protective tape is attached.

[0005] Patent Document 3 discloses a workpiece transport device (wafer transport device) that transports wafers by suction in a non-contact manner. This workpiece transport device is provided in a flat processing device that grinds the back surface of the wafer, and transports the wafer between various processing sections of the flat processing device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-299287 A [Patent Document 2] JP 2003-243483 A [Patent Document 3] JP 2017-92397 A Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, in recent years, it has become necessary for a workpiece transport device to directly hold and transport a workpiece depending on the type of workpiece. However, the workpiece transport device of Patent Document 2 is a device that indirectly transports a wafer via a support frame and a protective tape, and is not a device that directly holds and transports a workpiece.

[0008] On the other hand, the workpiece transport device of Patent Document 3 is a device that transports wafers by suction in a non-contact manner, but there is a problem that, for example, in the case of a workpiece with a warped or uneven surface or a workpiece with uneven thickness, the workpiece cannot be transported stably.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a workpiece transport device that can directly hold and transport a workpiece, even if the workpiece has a warped surface. [Means for solving the problem]

[0010] In order to achieve the object of the present invention, the work transporting device of the present invention is a work transporting device for directly holding and transporting a work, and is provided with a work holding means for directly holding the work, and a transporting means for transporting the work holding means, and the work holding means has a base connected to the transporting means, and a pair of work suction means provided at a distance from each other in positions opposite to each other on the base, the pair of work suction means for adsorbing the underside of the work, and a spacing change means for changing the spacing between the pair of work suction means.

[0011] According to one form of the present invention, it is preferable that the work transporting device is provided with a control unit for controlling the work transporting device, and the control unit controls the spacing change means and the work suction means to adsorb the underside of the work by the pair of work suction means so that the work is held by the work holding means, and then controls the transporting means to transport the work holding means.

[0012] According to one form of the present invention, a support member is provided on the base to support the suction means so that the suction means can be freely moved in the vertical direction, and it is preferable that the support member has a first biasing member capable of biasing the suction means upward, and a second biasing member capable of biasing the pair of suction means downward. Effect of the Invention

[0013] According to the present invention, even a workpiece having a warped surface can be directly held and transported. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of a dicing machine to which a workpiece transport device according to an embodiment is applied; [Diagram 2] FIG. 2 is a perspective view showing the configuration of a processing unit of the dicing device of FIG. [Diagram 3] Functional block diagram of the control device for the workpiece transport device [Figure 4] FIG. 3 is an overall perspective view of a suction unit constituting the workpiece transport device; [Diagram 5] A front view of the suction unit shown in FIG. [Figure 6] An explanatory diagram showing the workpiece transport operation in chronological order. [Figure 7] An explanatory diagram showing the workpiece transport operation in chronological order. [Figure 8] FIG. 1 is a front view showing the structure of the floating support mechanism [Figure 9] FIG. 9 is a perspective view of the floating support mechanism shown in FIG. 8; [Figure 10] FIG. 9 is a perspective view of the floating support mechanism shown in FIG. 8; [Figure 11]An explanatory diagram showing the operation of the floating support mechanism. [Figure 12] Diagram showing the variations in the shape of the workpiece and chuck table DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a workpiece transport device according to the present invention will now be described with reference to the accompanying drawings. In the embodiment, a dicing device will be described as an example of a processing device.

[0016] FIG. 1 is a perspective view of a dicing device 12 provided with a workpiece transport device 10 according to an embodiment.

[0017] 1, the dicing device 12 includes, in addition to the above-mentioned work transport device 10, a processing section 14 that processes a work W such as a semiconductor wafer, a cleaning section 16 that spin-cleans the processed work W, and a load port 18 on which a cassette containing a plurality of workpieces W is placed. Note that the workpiece W processed by the dicing device 12 has electronic components (not shown) formed on its upper surface.

[0018] In this specification, a three-dimensional orthogonal coordinate system with three axial directions (X-axis, Y-axis, and Z-axis) is used for explanation. The X-axis direction shown in Fig. 1 is the horizontal direction, and indicates the cutting feed direction of an X-table 20 (see Fig. 2) described later. The Y-axis direction is one of the horizontal directions perpendicular to the X-axis direction, and indicates the index feed direction of a blade 22 described later. Furthermore, the Z-axis direction is the vertical direction perpendicular to the X-axis and Y-axis directions, and indicates the cutting feed direction of the blade 22.

[0019] FIG. 2 is a perspective view showing the configuration of the processing unit 14. As shown in FIG.

[0020] 2, the processing unit 14 has an X-table 20 that is guided by a pair of X guide rails 26, 26 of an X-base 24 and is moved in the X-axis direction by a linear motor 28. A work table (chuck table) 32 is provided on the X-table 20 via a rotary table 30 that rotates in the θ direction.

[0021] The work table 32 is, for example, configured in a disk shape, and has a horizontally flat suction surface 34 on its upper surface, and a work W (see FIG. 1) is fixed to this suction surface 34 by vacuum suction.

[0022] A Y base 36 is erected above the X base 24 so as to straddle the X base 24. A pair of Y tables 40, 40 guided by a pair of Y guide rails 38, 38 and movable in the Y-axis direction are provided in front of the Y base 36. The Y tables 40, 40 are moved in the Y-axis direction by a Y-axis drive mechanism (not shown) provided on the Y base 36.

[0023] The Y tables 40 are provided with Z tables 44 which are driven in the Z-axis direction by a Z-axis drive mechanism (not shown). High-frequency built-in spindle motors 46 are fixed to the Z tables 44 in a state facing each other in the Y-axis direction, and blades 22 are fixed to the tips of spindles 48 of the spindle motors 46 in a state facing each other in the Y-axis direction. These spindle motors 46 are supported by the Y tables 40 via the Z tables 44, and the axes of the spindles 48 are arranged along the Y-axis direction, which is the direction in which the Y tables 40 move.

[0024] As an example of the blade 22, an electrodeposited blade in which diamond abrasive grains or CBN (cubic boron nitride) abrasive grains are electrodeposited with nickel is shown. In addition to the electrodeposited blade, a metal resin bonded blade in which metal powder is mixed and bonded with resin can also be used. The blade 22 is rotated at a high speed of, for example, 6000 rpm to 80000 rpm by the spindle motor 46.

[0025] According to the processing unit 14 configured in this manner, the work table 32 is fed for cutting in the X-axis direction by the X-table 20 and rotated in the θ direction by the rotary table 30. The blades 22, 22 are index-fed in the Y-axis direction by the Y-axis drive mechanism and are cut-fed in the Z-axis direction by the Z-axis drive mechanism. By such operation of the processing unit 14, the workpiece W is cut into a grid pattern.

[0026] 1, the cleaning unit 16 includes a spinner table (chuck table) 52 having an adsorption surface 50 on its upper surface, and a nozzle (not shown) that sprays cleaning water toward the workpiece on the spinner table 52. The workpiece W machined by the processing unit 14 is transported from the work table 32 to the spinner table 52 by the work transport device 10, and then is adsorbed by the adsorption surface 50, rotated, and cleaned with cleaning water sprayed from the nozzle.

[0027] Next, the workpiece transport device 10 according to the embodiment will be described.

[0028] 1, the workpiece transport device 10 includes an arm 60 and a suction unit 62. Here, the suction unit 62 is an example of the workpiece holding means of the present invention.

[0029] The operation of the workpiece transport device 10 of the embodiment is controlled by a control device 63 that controls the dicing device 12, as shown in FIG.

[0030] Fig. 3 is a functional block diagram of the control device 63 of the dicing device 12. Note that in the functional block diagram of Fig. 3, only elements related to the work transportation device 10 are shown, and elements not directly related to the work transportation device 10 are omitted. Here, the control device 63 is an example of the control unit of the present invention.

[0031] As shown in Fig. 3, the control device 63 includes various arithmetic processing circuits including a central processing unit (CPU) (not shown), a memory such as a read only memory (ROM) or a random access memory (RAM), an input device such as a keyboard, and an output device such as a monitor. The functions of each part of the control device 63 are realized by the CPU executing a program stored in the memory. As shown in Fig. 3, the control device 63 includes a general control unit 63A, which general controls a transport control unit 63B, an interval change control unit 63C, and a suction control unit 63D.

[0032] The transport control section 63B controls the transport device 66. The transport device 66 has a horizontal drive section that moves the arm 60 horizontally along the XY horizontal plane, and an elevation drive section that moves the arm 60 up and down in the vertical direction. To be more specific, a rotating shaft 64 (see FIG. 1) that is disposed along the vertical axis at the base end of the arm 60 is connected to the output shaft of a motor that constitutes the horizontal drive section. This causes the arm 60 to move horizontally by the motor of the horizontal drive section. The elevation drive section also has a motor that moves the arm 60 in the vertical direction. This causes the arm 60 to move vertically by the motor of the elevation drive section. Here, the transport device 66 is an example of the transport means of the present invention.

[0033] The gap changer 63B controls cylinder devices 76, 76 to change the gap between suction pads 74, 74 (see FIG. 5) which will be described later. Here, the cylinder devices 76, 76 are an example of the gap changer of the present invention.

[0034] The suction control unit 63D controls the suction device 68 that applies suction force to the suction pads 74, 74 (see FIG. 5).

[0035] 1, the suction unit 62 is provided at the tip of the arm 60 via a connecting member 70. With this configuration, the suction unit 62 is transported in the horizontal and vertical directions by the transport device 66 shown in FIG.

[0036] FIG. 4 is a perspective view showing the overall configuration of the suction unit 62, and FIG. 5 is a front view of the suction unit 62 shown in FIG.

[0037] 4 and 5, the suction unit 62 includes a base 72, a pair of suction pads 74, 74, and a pair of cylinder devices 76, 76. Here, the base 72 is an example of a base of the present invention, and the pair of suction pads 74, 74 are an example of a pair of suction means of the present invention.

[0038] The base 72 is configured, for example, in the shape of a rectangular plate. The base 72 has a connecting portion 78 at its center, and is connected to the tip of the arm 60 by connecting a connecting member 70 (see FIG. 1) to the connecting portion 78. In FIG. 4, the base 72 has a long side 72A arranged along the X-axis direction and a short side 72B arranged along the Y-axis direction.

[0039] The pair of suction pads 74, 74 are disposed on the short side portions 72B, 72B of the base 72 facing each other in the direction of the long side 72A, and are provided at a distance from each other on the base 72, and are also provided on the base 72 via hooks 80, 80, respectively. These suction pads 74 are fixed to the lower portion 80A of the hook 80 with their suction ports 82 facing upward. The suction pad 74 is configured in a rectangular parallelepiped shape, for example, and is fixed to the hook 80 with its long side 74A aligned along the short side 72B. A plurality of suction ports 82 are disposed along the long side 74A.

[0040] The hook 80 has an opening 80B in the center through which the base 72 passes. A linear guide 84 is fixed to the lower surface of an upper portion 80C of the hook 80. The linear guide 84 is movably engaged with a guide rail 86 arranged on the upper surface of the base 72 along the long side 72A. This allows the pair of suction pads 74, 74, together with the hooks 80, 80, to be movably disposed in the direction of the long side 72A between a close position where they are close to each other and a spaced position where they are spaced apart from each other.

[0041] An L-shaped bracket 88 is fixed to the upper surface of the upper portion 80C of the hook 80, and a piston 90 (see FIG. 5) of the cylinder device 76 is fixed to the bracket 88. The cylinder device 76 is fixed to a base 92 so that the axial direction of the piston 90 is along the long side 72A, and the base 92 is fixed to the upper surface of the base 72 across the guide rail 86. Therefore, when the pistons 90 are simultaneously extended and contracted by the pair of cylinder devices 76, the pair of suction pads 74, together with the hooks 80, are moved between the above-mentioned separated position and close position, and the distance between the suction pads 74, is changed.

[0042] 5, when pistons 90, 90 are simultaneously contracted by cylinder devices 76, 76 and the suction pads 74, 74 are positioned in close proximity, edge portions WA, WA on both sides of the back surface (lower surface) of the workpiece W are sucked and held by suction ports 82, 82 of the suction pads 74, 74. These edge portions WA, WA are not the attracted surface WB that is sucked by the suction surface 34 of the work table 32 and the suction surface 50 of the spinner table 52, but are configured as non-sucked surfaces located outside the attracted surface WB.

[0043] Next, the operation of the workpiece transport device 10 constructed as above will be described.

[0044] 6 to 7 are operation diagrams of the work transportation device 10, which show the time series of the operation of transporting the work W from the work table 32 to the spinner table 52. The transport operation of the arm 60, the interval change operation of the suction pads 74, 74, and the suction operation of the suction pads 74, 74 in Fig. 6 to Fig. 7 are executed by the general control unit 63A of the control device 63 shown in Fig. 3 controlling the transport control unit 63B, the interval change control unit 63C, and the suction control unit 63D, respectively.

[0045] 6A shows the initial state before the workpiece W sucked and held on the worktable 32 is transported by the work transport device 10. In this initial state, the arm 60 is located at a retracted position retracted above the worktable 32, and the suction pads 74, 74 (as well as the hooks 80, 80) are located at a close position by the cylinder devices 76, 76. Note that the suction operation of the suction pads 74, 74 at this time is OFF, the suction state of the worktable 32 is ON, and the suction state of the spinner table 52 (see FIG. 1) is OFF. This is the state.

[0046] Next, Fig. 6B shows a state in which the pistons 90, 90 of the cylinder devices 76, 76 are extended to move the suction pads 74, 74 (as well as the hooks 80, 80) from the close position to the separate position. At this time, the suction states of the suction pads 74, 74, the work table 32, and the spinner table 52 also remain in the initial state of Fig. 6A.

[0047] Next, Fig. 6C shows a state where the arm 60 is moved downward by the transport device 66 (see Fig. 3) to place the hooks 80, 80 in the hook opening and closing operation position. At this time, the suction states of the suction pads 74, 74, the work table 32 and the spinner table 52 also remain in the initial state of Fig. 6A. The hook opening and closing operation position is a position where the suction port 82 (see Fig. 4) of the suction pad 74 is located below the suction surface 34 of the work table 32.

[0048] Next, Fig. 6D shows a state in which the pistons 90, 90 of the cylinder devices 76, 76 are contracted to move the suction pads 74, 74 (as well as the hooks 80, 80) from the distant position (see Fig. 6B) to the close position. This operation positions the suction ports 82, 82 of the suction pads 74, 74 directly below the curved edges WA, WA of the workpiece W. At this time, the suction states of the suction pads 74, 74, the work table 32, and the spinner table 52 also remain in the initial states of Fig. 6A.

[0049] Next, Fig. 6E in Fig. 6 shows a state in which the arm 60 is moved upward by the transport device 66 (see Fig. 3) to the receiving position of the workpiece W, and the suction operation of the suction pads 74, 74 is switched from OFF to ON. Fig. 6E in Fig. 6 also shows a state in which the suction state of the worktable 32 is switched from ON to OFF, and switched to an air blow operation in which air is sprayed to the outside from the suction surface 34 of the worktable 32. This allows the workpiece W adsorbed to the worktable 32 to be smoothly delivered to the suction pads 74, 74. The receiving position of the workpiece W is a position where the suction port 82 abuts against the warped edges WA, WA, and is set above the suction surface 34 of the worktable 32.

[0050] 7A shows a state in which the arm 60 is raised by the lifting device 68 (see FIG. 3) to place the workpiece W in the horizontal transfer position. At this time, the suction operation of the suction pads 74, 74 is ON, and the air blowing operation of the worktable 32 is stopped and the suction state is OFF.

[0051] Next, Fig. 7B shows a state in which the arm 60 is moved horizontally by the transport device 66 (see Fig. 3) to position the workpiece W directly above the spinner table 52, and then the arm 60 is moved downward by the transport device 66 to a position for transferring the workpiece W to the spinner table 52, and then the suction state of the spinner table 52 is switched from OFF to ON. Fig. 7B also shows that the suction pads 74, 74 are moved downward toward the suction surface 50 of the spinner table 52, and the suction port 82 (see Fig. 4) is moved to a position on the same plane as the suction surface 50.

[0052] As a result, even if the central portion of the workpiece W is curved downward in a convex shape, the suction port 82 (see Figure 4) that adsorbs the edges WA, WA is moved to a position on the same plane as the suction surface 50, so that the workpiece W can be securely adsorbed and held on the spinner table 52.

[0053] 7C shows a state in which the suction state of the suction pads 74, 74 is switched from the ON state to the OFF state, and the arm 60 is moved downward by the transport device 66 (see FIG. 3) while switching to an air blowing operation in which air is sprayed to the outside from the suction port 82. This allows the suction between the suction port 82 and the edges WA, WA to be smoothly released.

[0054] 7D shows a state in which the pistons 90, 90 of the cylinder devices 76, 76 are extended to place the suction pads 74, 74 (as well as the hooks 80, 80) in the hook opening / closing operation position (see 6C in FIG. 6). This operation causes the suction pads 74, 74 to retreat outward from positions directly below the edges WA, WA of the workpiece W.

[0055] Next, Fig. 7E in Fig. 7 shows a state in which the arm 60 has been moved upward from the spinner table 52 by the transport device 66 (Fig. 3). Thereafter, the workpiece W is washed by the rotation of the spinner table 52. Then, after washing is completed, the workpiece W is held by the work transport device 10 and stored in a cassette in the load port 18 (see Fig. 1). Note that the method of transport from the spinner table 52 to the load port 18 by the work transport device 10 is substantially the same as the transport from the work table 32 to the spinner table 52 described above, and therefore a description thereof will be omitted.

[0056] Thus, according to the embodiment of the work transport device 10, it is equipped with an suction unit 62 that directly holds the work W, and a transport device 66 that transports the suction unit 62, and the suction unit 62 has a base 72 connected to the arm 60, a pair of suction pads 74, 74 that are arranged at a distance from each other in positions opposite each other on the base 72 and adsorb the underside of the work W, and cylinder devices 76, 76 that change the spacing between the pair of suction pads 74, 74, so that even a work W with a warped surface can be directly held and transported.

[0057] In addition, according to the embodiment of the workpiece transport device 10, after the edge portions WA, WA of the back surface of the workpiece W are adsorbed by the suction ports 82 of the suction pad 74, the suction ports 82, 82 are moved downward to a position on the same plane as the suction surface 50, so that the warped workpiece W can be reliably adsorbed to the spinner table 52.

[0058] In addition, in a preferred embodiment, it is preferable to move the suction port 82 to a position beyond the above-mentioned position on the same plane in the downward direction toward the suction surface 50 of the spinner table 52, where the suction pads 74, 74 are positioned. This allows the attracted surface WB (see FIG. 5) of the workpiece W to be pressed against the suction surface 50 of the spinner table 52 with the edges WA, WA being attracted by the suction pads 74, 74, so that the workpiece W can be effectively attracted and held on the spinner table 52. Note that the position beyond the above-mentioned position on the same plane is, for example, a position where the workpiece W will not be damaged even if the suction port 82 is moved to a position beyond the position on the same plane, and this position is set depending on the rigidity of the workpiece W, etc.

[0059] Fig. 8 is a front view showing the structure of a floating support mechanism 100 that supports the suction pad 74 in a floating state on the base 72. Fig. 9 and Fig. 10 are perspective views of the floating support mechanism 100 shown in Fig. 8, seen from different directions.

[0060] As shown in FIGS. 8 to 10, the floating support mechanism 100 has pad support members 102, 102 that support a pair of suction pads 74, 74 movably in the vertical direction relative to the base 72.

[0061] As shown in FIG. 9, the pad support member 102 has a rectangular base 104 connected to the piston 90 of the cylinder device 76, a crank-shaped bracket 106 connected to the base 104 and having the suction pad 74 fixed to its lower part, and a shaft 112 arranged along the vertical direction.

[0062] 10, the bracket 106 has a pair of elongated holes 114, 114 formed in the upper portion thereof along the vertical direction, and is connected to the base 104 via pins 116, 116 inserted into the elongated holes 114, 114. As a result, the base 104 and the bracket 106 are connected by a linear guide member consisting of the elongated holes 114, 114 and the pins 116, 116 so as to be movable relative to each other in the vertical direction.

[0063] As shown in Fig. 8, shaft 112 is disposed so as to penetrate vertically through through hole 108 of base 104 via sleeve bearing 110 (see Fig. 11). As a result, base 104 and shaft 112 are connected by sleeve bearing 110 so as to be relatively movable in the vertical direction. In addition, a lower portion of shaft 112 is fixed to horizontal portion 107 of bracket 106 by screw 118 (see Fig. 11).

[0064] The pad support member 102 thus configured includes, as shown in FIG. 8, a coil spring 120 capable of biasing the suction pad 74 upward, and a coil spring 122 capable of biasing the suction pad 74 downward.

[0065] The coil spring 120 is fitted around the shaft 112 and disposed between the upper flange portion 113 of the shaft 112 and the upper surface of the base 104. In addition, the coil spring 122 is fitted around the shaft 112 and disposed between the lower surface of the base 104 and the horizontal portion 107 of the bracket 106. By providing such coil springs 120, 122, the suction pad 74 is supported in a floating state on the base 104 via the bracket 106 and the shaft 112. Here, the coil springs 120, 122 are an example of the first and second biasing members of the present invention.

[0066] Next, the operation of the floating support mechanism 100 constructed as above will be described with reference to the cross-sectional view shown in FIG.

[0067] The cross-sectional view shown in Fig. 11 shows, as an example, a case where the workpiece W is lifted from the worktable 32 (see Fig. 6E). Note that the workpiece W shown in Fig. 11 is a workpiece having a shape in which the central portion is warped downward in a convex manner.

[0068] As shown in 11A of Fig. 11, after the suction pad 74 comes into contact with the edge WA of the back surface of the workpiece, when the base 72 (see Fig. 9) is moved upward to lift the suction pad 74 via the base 104, the suction pad 74, the bracket 106, and the shaft 112 are restricted from moving upward because the suction pad 74 is in contact with the edge WA, and the base 104 moves upward along the shaft 112. Then, as shown in 11B of Fig. 11, the coil spring 120 contracts from the state shown in 11A of Fig. 11 by the lift amount L of the base 104, and the biasing force of the coil spring 120 generated at that time is transmitted to the suction pad 74 via the shaft 112 and the bracket 106, and the suction pad 74 is biased upward. As a result, the biasing force of the coil spring 120 can be used to effectively press the suction pad 74 against the edge WA of the workpiece W.

[0069] Furthermore, when the amount of warping of the edge portion WA is not uniform over the entire area of ​​the edge portion WA, the suction pads 74 can be supported by the floating support mechanism 100 in this manner, and all of the suction pads 74 can be attached to the edge portion WA by moving the base 104 upward as shown in 11B of Fig. 11. Furthermore, the coil spring 120 contracts and absorbs the excess force applied to the edge portion WA from the suction pads 74 when the base 104 is moved upward, so damage to the edge portion WA caused by the lifting of the base 104 can be prevented.

[0070] 11B, when the suction state of the work table 32 is switched from ON to OFF, the shaft 112 and the bracket 106 move upward by the biasing force of the coil spring 120, and the suction pad 74 moves upward. This makes it possible to effectively lift the work W from the work table 32 by utilizing the biasing force of the coil spring 120.

[0071] On the other hand, when the workpiece W, the edge portion WA of which is sucked by the suction pad 74, is to be sucked onto the spinner table 52 (see 7B in FIG. 7), the base 104 is moved downward by the arm 60. At this time, if the suction port 82 is to be moved beyond the position on the same plane as the suction surface 50, the suction pad 74, the bracket 106, and the shaft 112 are restricted from moving downward, since the suction surface WB of the workpiece W is in contact with the spinner table 52, and the base 104 moves downward along the shaft 112. Then, the coil spring 122 contracts from the state of 11A in FIG. 11 by the amount of descent of the base 104, and the urging force of the coil spring 122 generated at that time is transmitted to the suction pad 74 via the bracket 106, and the suction pad 74 is urged downward. As a result, the urging force of the coil spring 122 can be used to effectively press the workpiece W against the spinner table 52.

[0072] In addition, when the workpiece W has a shape in which the central portion is warped upward in a convex manner or is not warped, and the workpiece W is lifted from the work table 32, the suction pad 74 is moved to a position slightly higher than the back surface of the workpiece W. At this time, the coil spring 120 contracts and absorbs the excess force applied to the edge portion WA from the suction pad 74, thereby preventing damage to the edge portion WA caused by the rising of the base 104.

[0073] In addition, in the case of a workpiece W having a shape in which the central portion is warped upward in a convex manner or a workpiece W that is not warped, when the workpiece W having its edge portion WA adsorbed by the suction pad 74 is to be adsorbed onto the spinner table 52, the suction pad 74 is moved to a position slightly lower than the back surface of the workpiece W. At this time, the excess force applied to the edge portion WA from the suction pad 74 is absorbed by the coil spring 122 by contracting, thereby preventing damage to the edge portion WA caused by the lowering of the base 104.

[0074] As described above, by adopting the above-mentioned floating support mechanism 100 in the workpiece transport device 10, even if the central portion of the workpiece W has a shape that is convexly warped downward, or even if the central portion of the workpiece W has a shape that is convexly warped upward, the edge WA of the workpiece W can be effectively adsorbed and the workpiece W can be effectively pressed against the chuck table.

[0075] 12A to 12F are explanatory diagrams showing variations of workpieces and chuck tables applicable to the workpiece transportation device of the present invention. Note that the workpieces shown in FIG. 12 will be described with reference characters W1 to W6, and the chuck tables will be described with reference characters C1 to C6.

[0076] The workpiece W1 shown in 12A of Fig. 12 is configured to have a substantially square shape in a plan view, and the chuck table C1 is configured to have a substantially square shape that is slightly smaller than the outer shape of the workpiece W1. Four suction pads 74 are shown in 12A of Fig. 12, and two opposing edges of the workpiece W1 are suctioned by two suction pads 74, respectively.

[0077] The workpiece W2 shown in FIG. 12B is configured to have a substantially square shape in a plan view, and the chuck table C2 is configured to have a substantially square shape that is substantially the same as the outer shape of the workpiece W2. Four suction pads 74 are shown in the figure, and two opposing edges of the workpiece W2 are suctioned by two suction pads 74, respectively. In addition, concave relief grooves 130 that accommodate the four suction pads 74 are formed in two opposing edges of the chuck table C2. By providing the chuck table C2 with such relief grooves 130, the size of the chuck table C2 can be made close to the size of the workpiece W2, and therefore the holding force of the chuck table C2 for the workpiece W2 can be improved.

[0078] 12C shows a workpiece W3 that is octagonal in plan view, and the chuck table C3 is also octagonal and slightly smaller than the outer shape of the workpiece W3. Four suction pads 74 are shown in the figure, and two opposing edges of the workpiece W3 are suctioned by two suction pads 74, respectively.

[0079] The workpiece W4 shown in 12D of Fig. 12 is configured to be octagonal in plan view, and the chuck table C4 is configured to be octagonal in shape that is approximately the same as the outer shape of the workpiece W4. Four suction pads 74 are shown in the figure, and two opposing edges of the workpiece W4 are suctioned by two suction pads 74 each. In addition, two opposing edges of the chuck table C4 are formed with recessed escape grooves 132 that accommodate the four suction pads 74, so that the holding force of the chuck table C4 for the workpiece W4 can be improved, similar to the chuck table C2 shown in 12B of Fig. 12.

[0080] 12E shows a workpiece W5 that is circular in plan view, and the chuck table C5 is circular and slightly smaller than the outer shape of the workpiece W5. Four suction pads 74 are shown in the figure, and two suction pads 74 each suction the opposing peripheral portions of the workpiece W5.

[0081] The workpiece W6 shown in 12F of Fig. 12 is circular in plan view, and the chuck table C6 is circular in shape, approximately equal to the outer shape of the workpiece W6. Four suction pads 74 are shown in the figure, and two suction pads 74 are used to suction the opposing peripheral portions of the workpiece W6. In addition, recessed escape grooves 134 that accommodate the four suction pads 74 are formed in the opposing peripheral portions of the chuck table C6, so that the holding force of the workpiece W6 by the chuck table C6 can be improved, similar to the chuck tables C2 and C4 shown in 12B and 12D of Fig. 12.

[0082] In the embodiment, the workpiece W having a warped surface is the target for transport, but the workpiece W to be transported is not limited to this. That is, according to the workpiece transport device of the present invention, it is possible to directly hold and transport a workpiece having an uneven surface, a workpiece having a variation in thickness, or a workpiece having no warp or unevenness and a surface parallel to the chuck table.

[0083] Although the embodiment of the present invention has been described above, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the spirit of the present invention. [Explanation of symbols]

[0084] 10...workpiece transport device, 12...dicing device, 14...processing section, 16...cleaning section, 18...load port, 20...X table, 22...blade, 24...X base, 26...X guide rail, 28...linear motor, 30...rotary table, 32...work table, 34...suction surface, 36...Y base, 38...Y guide rail, 40...Y table, 44...Z table, 46...spindle motor, 48...spindle, 50...suction surface, 52...spinner table, 60...arm, 62...suction unit, 63...control device, 64...rotary axis, 66...transport device, 68...suction device, 70...connecting member, 72...base, 74...suction pad, 76...cylinder device, 78...connecting portion, 80...hook, 82...suction port, 84...linear guide, 86...guide rail, 88...bracket, 90...piston, 92...base, 100...floating support mechanism, 102...pad support member, 104...base, 106...bracket, 107...horizontal portion, 108...through hole, 110...sleeve bearing, 112...shaft, 114...long hole, 116...pin, 118...screw, 120...coil spring, 122...coil spring

Claims

1. A workpiece holding device for directly holding a warped workpiece, comprising: With the base, A pair of workpiece suction means provided on the base for suctioning the workpiece; A gap change means for changing the gap between the pair of workpiece suction means; A work holding device comprising:

2. a control unit that controls the interval change means and the workpiece suction means to suction the workpiece by the pair of workpiece suction means and hold the workpiece on the workpiece suction means, The workpiece holding device according to claim 1 .

3. a support member that supports the workpiece suction means so as to be movable in a vertical direction relative to the base; The support member has a first biasing member capable of biasing the workpiece suction means upward, and a second biasing member capable of biasing the workpiece suction means downward. The workpiece holding device according to claim 1 or 2.

4. a support member that supports the workpiece suction means so as to be movable in a vertical direction relative to the base; the support member includes a base member, a bracket that is movable in the vertical direction relative to the base member and to which the workpiece suction means is fixed, and a shaft that is connected to the base member and is movable in the vertical direction, a first biasing member that biases the shaft in one direction in the vertical direction relative to the base member, and a second biasing member that biases the bracket in the other direction in the vertical direction relative to the base member, and a floating mechanism that supports the workpiece suction means in a floating state on the base member via the bracket and the shaft. The workpiece holding device according to claim 1 or 2.

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