Conveying device

Abstract

To provide a transport device that does not allow dust to adhere to the upper surface of an object to be held when the object to be held suction-held by a transport pad is removed from the transport pad.SOLUTION: In a transport device 60, a transport pad 63 includes a plate 63A connected to a lifting mechanism 61, a shaft 66 in which a suction path 66A is formed, a suction cup 64 disposed at the lower end of the shaft 66, a head 67 disposed at the upper end of the shaft 66, an inlet 67a opening to the head 67, and a communication path 67A formed inside the head 67, and when a wafer (object to be held) W being suction-held is removed from the suction cup 64, a control unit 100 is configured to close a valve V and lower the transfer pad 63, and further lower the transport pad 63 to open the inlet 67a of the head 67 to allow atmospheric air to be taken into the suction path 66A of the shaft 66.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a conveying apparatus that suctions, holds, and conveys an object to be held such as a wafer by means of suction pads. Background Art

[0002] For example, in a processing apparatus that divides thin disc-shaped wafers, a work set formed by adhering a tape to a ring frame and a wafer is suction-held by a conveying apparatus and conveyed to a predetermined position. The conveying apparatus herein includes: a conveying pad provided with a plurality of suction pads that are in close contact with the upper surface of the ring frame of the work set and suction the ring frame; an elevating mechanism that elevates and lowers the conveying pad; and a suction source by which the suction pads suction the upper surface of the ring frame (see, for example, Patent Documents 1 and 2).

[0003] In such a conveying mechanism, by communicating a plurality of suction pads provided on the conveying pad with a suction source, suction force (negative pressure) is generated in each suction pad to suction and hold the work set. Then, when detaching the suction-held work set from the conveying pad, air is ejected from the suction ports of the suction pads to eliminate the suction force of the suction pads, thereby making it easy to detach the work set from the conveying pad. Prior Art Literature Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Publication No. 2001-007058 Patent Document 2 Japanese Unexamined Patent Publication No. 2017-112227 Summary of the Invention Problem to be Solved by the Invention

[0005] However, as mentioned above, when air is sprayed from the suction port of the suction cup to detach the workset from the transport pad, dust inside the processing equipment is scattered into the surroundings by the air, and when the ring frame is sucked in, dust sucked in by the suction cup is ejected, causing dust to adhere to the top surface of the wafer.

[0006] The present invention has been made in view of the above problems, and its object is to provide a conveying device that prevents dust from adhering to the upper surface of an object when the object held by the conveying pad is released from the conveying pad. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a conveying device for conveying an object to be held, comprising: a conveying pad that holds the upper surface of an object to be held by suction cup; a lifting mechanism for raising and lowering the conveying pad; a suction source for drawing in the suction cup; a valve for disconnecting and disconnecting communication between the suction source and the suction cup; and a control unit, wherein the conveying pad comprises: a plate connected to the lifting mechanism; a shaft that extends vertically and is supported by the plate so as to be able to move up and down, and has a suction passage extending vertically formed inside; a suction cup disposed at the lower end of the shaft, with the lower end of the suction passage opening as a suction port to hold the upper surface of an object to be held by suction; a head disposed at the upper end of the shaft and having a mounting surface that is placed on the mounting surface of the plate by the weight of the shaft; an inlet opening at the mounting surface of the head; and a communication passage formed inside the head that connects the upper end of the suction passage and the inlet. The control unit is characterized by the following controls: when using the suction cup to hold an object, it lowers the transport pad to bring the suction cup into contact with the upper surface of the object to be held, and opens the valve while keeping the entrance closed on the mounting surface, thereby connecting the suction port and the suction source; and when separating the object being held from the suction cup, it closes the valve, lowers the transport pad to bring the lower surface of the object to be held into contact with the upper surface of the transport location, and further lowers the transport pad to raise the head relative to the plate, separating the mounted surface from the mounting surface, opening the entrance that was closed on the mounting surface, and allowing air to be drawn into the suction passage. [Effects of the Invention]

[0008] According to the present invention, when separating an object held by the suction cup of the transport pad from the suction cup, the valve is closed to stop the suction of air into the suction cup, and the transport pad is lowered so that the lower surface of the object to be held is in contact with the upper surface of the transport location. Then, the transport pad is lowered further, and the head of the shaft is raised relative to the plate so that the mounting surface of the head is separated from the mounting surface of the plate. As a result, the inlet of the head, which was blocked by the mounting surface of the plate, is opened, and air is drawn into the suction passage of the head. Consequently, the internal pressure of the suction cup becomes atmospheric pressure, eliminating the suction force of the suction cup, and the object to be held can be easily separated from the transport pad. Furthermore, in this case, since no air is ejected from the suction cup, dust is not scattered into the surroundings, and the adhesion of dust to the upper surface of the object to be held is reliably prevented. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a cutting apparatus equipped with a conveying device according to the present invention. [Figure 2] (a) to (d) are explanatory diagrams illustrating the operation of the conveying device according to the present invention. [Figure 3] This is an enlarged detail view of section A in Figure 2(a). [Figure 4] This is an enlarged detail view of section B in Figure 2(c). [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, the transport device according to the present invention will be described as an example in which it is provided in a wafer cutting apparatus.

[0011] [Configuration of the cutting machine] First, the overall configuration of the wafer cutting machine will be described below based on Figure 1. In the following description, the left-right direction in Figure 1 will be referred to as the "X-axis direction," the front-back direction as the "Y-axis direction," and the up-down direction as the "Z-axis direction."

[0012] The cutting apparatus 1 shown in Figure 1 is a so-called dual dicer and comprises a cassette stage 10 on which a cassette 10A containing multiple worksets WS including wafers W which are both workpieces and objects to be held is placed, a cassette lifting mechanism 20 for raising and lowering the cassette stage 10, a pull-out mechanism 30 for pulling out the worksets WS from the cassette 10A placed on the cassette stage 10, a temporary placement mechanism 40 for temporarily placing the worksets WS pulled out by the pull-out mechanism 30, and a chuck for holding the worksets WS. The main components of the system are a table 50, a first transport device 60 that suction-holds the upper surface of the ring frame F of the work set WS temporarily placed on the temporary placement mechanism 40 and transports the work set WS to the chuck table 50, a processing mechanism 70 that processes the wafer W of the work set WS held on the chuck table 50, a spinner cleaning mechanism 80 that cleans the wafer W after cutting, a second transport device 90 that transports the work set WS, including the cleaned wafer W, from the chuck table 50 to the spinner cleaning mechanism 80, and a control unit 100.

[0013] Next, we will explain the configurations of the main components that make up the cutting apparatus 1: the cassette stage 10, the cassette lifting mechanism 20, the drawer mechanism 30, the temporary placement mechanism 40, the chuck table 50, the first conveying device 60, the processing mechanism 70, the spinner cleaning mechanism 80, the second conveying device 90, and the control unit 100.

[0014] (Cassette Stage) The cutting apparatus 1 shown in Figure 1 is equipped with a base 2 that supports each component. A rectangular opening 3, which is long in the X-axis direction, is located in the center of the base 2 in the Y-axis direction. A rectangular plate-shaped cassette stage 10 that moves up and down along the vertical direction (Z-axis direction) is provided at the right corner (+X-axis direction) of the front (-Y-axis direction) of this opening 3. A rectangular box-shaped cassette 10A that houses multiple work sets WS, including disc-shaped wafers W which are the workpieces, is arranged on the upper surface of the cassette stage 10. For the sake of explanation, in Figure 1, only the outline of the cassette 10A is shown with a dashed line.

[0015] Here, the wafer W is divided into numerous rectangular regions by multiple mutually orthogonal division lines (not shown) called streets, which are arranged in a grid pattern on its surface (top surface in Figure 1). Devices D such as ICs and LSIs are formed in each rectangular region. Multiple semiconductor chips are formed by cutting the wafer W, on which numerous devices D are formed, along the division lines. A workset WS is then formed by attaching tape T to the wafer W and the ring frame F, integrating the two.

[0016] (Cassette lifting mechanism) The cassette lifting mechanism 20 is a mechanism that moves the cassette stage 10 up and down along the Z-axis direction (vertical direction) together with the cassette 10A, and is composed of a pair of vertically standing guide rails 21 that guide the lifting and lowering movement of the cassette stage 10, a rotatable ball screw 22 vertically positioned between the guide rails 21, and a servo motor 23 that rotationally drives the ball screw 22, with the upper end of the ball screw 22 screwed into a nut member (not shown) attached to the lower surface of the cassette stage 10.

[0017] Therefore, by starting the servo motor 23 and rotating the ball screw 22 in forward and reverse directions, the cassette stage 10, to which a nut member (not shown) that the ball screw 22 is screwed is attached, moves up and down along the pair of guide rails 21 in the Z-axis direction together with the cassette 10A placed on it. The servo motor 23 is electrically connected to the control unit 100, and its drive is controlled by the control unit 100.

[0018] (Drawer mechanism) The push-pull mechanism 30 is a mechanism for pulling out one workset WS from the cassette 10A in the +Y axis direction (rearward), and includes a ball screw 31 and a guide rail 32 arranged vertically and parallel to each other along the Y axis direction (front-to-back direction) on the +X axis end face (right end face) of the base 2, and an inverted L-shaped pull-out arm 33 that moves along the ball screw 31 and the guide rail 32 in the Y axis direction (front-to-back direction).

[0019] Here, a servo motor 34 serving as a drive source is provided at one axial end (the left end in FIG. 1) of the ball screw 31, and the other axial end (the right end in FIG. 1) of the ball screw 31 is rotatably supported on the base 2 by a bearing 35. The lower end of the vertical portion 33a of the extraction arm 33 is slidably inserted through and supported by the guide rail 32, and the ball screw 31 is threaded through the upper portion of the vertical portion 33a in the height direction. Further, a gripping portion 36 for gripping a workpiece set WS is provided at the tip end of a horizontal portion 33b that is bent at a right angle from the upper end of the vertical portion 33a of the extraction arm 33 and extends horizontally in the -X-axis direction (leftward). The servo motor 34 is electrically connected to the control unit 100, and the driving thereof is controlled by the control unit 100.

[0020] (Temporary Placement Mechanism) The temporary placement mechanism 40 is a mechanism that temporarily temporarily places the workpiece set WS pulled out from the cassette 10A by the pull-out mechanism 30, and includes a pair of left and right frame guides bent in an inverted L shape, and a gap adjusting mechanism 42 that adjusts the gap between these frame guides. Here, the pair of frame guides 41 can move in opposite directions (that is, the direction toward each other and the direction away from each other) in the left-right direction (X-axis direction) along a slit-shaped guide hole 2a formed linearly along the X-axis direction (left-right direction) on the upper surface of the base 2.

[0021] Further, the gap adjusting mechanism 42 is a mechanism for moving the pair of frame guides in the direction of narrowing or widening the gap therebetween, and is housed inside the base 2 as shown by broken lines in FIG. 1. Here, illustration and description of the specific configuration of the gap adjusting mechanism 42 are omitted, and the gap adjusting mechanism 42 is configured by a known ball screw mechanism or the like.

[0022] (Chuck Table) The chuck table 50 is a disc-shaped member that holds the workpiece set WS, and is positioned so that its holding surface (top surface) is exposed to an opening 3 that opens into the upper surface of the base 2. Four clamps 51 are arranged around the chuck table 50 at equal angular pitches (90° pitches) in the circumferential direction for fixing the ring frame F of the workpiece set WS from all four sides.

[0023] Here, the chuck table 50 is rotated about a vertical axis by a rotation mechanism (not shown) located below it, and can also reciprocate along the X-axis direction (left-right direction) by an X-axis direction movement mechanism (not shown) located below it.

[0024] (First conveying device) The first transport device 60 is used to transport the work set WS, which has been pulled out from the cassette 10A by the pull-out mechanism 30 and temporarily placed on a pair of left and right frame guides 41, to the chuck table 50 by suction and holding. It can move up and down in the Z-axis direction (vertical direction) by the lifting mechanism 61 shown in Figure 2, and can also move horizontally along the X-axis direction on the XY plane by an X-axis direction movement mechanism (not shown). Although not shown, the lifting mechanism 61 consists of a guide rail extending in the Z-axis direction, a ball screw extending in the Z-axis direction parallel to the guide rail, a motor that rotates the ball screw, and an encoder that detects the rotation angle of the ball screw.

[0025] This first conveying device 60 is equipped with a conveying pad 63 that is H-shaped in plan view and attached to the lower end of a vertical rod 62, and four suction cups 64 are attached to the lower surface of this conveying pad 63.

[0026] Here, the transport pad 63 comprises, as shown in Figure 2, a horizontal plate 63A with an H-shape in plan view connected to the lifting mechanism 61 via an arm 65, and, as shown in Figures 3 and 4, a total of four cylindrical shafts 66 (only one is shown in Figures 3 and 4) that are slidably inserted vertically into the four corners of the plate 63A, a head 67 attached to the upper end of each shaft 66, and the suction cups 64 attached to the outer circumference of the lower end of each shaft 66. Each suction cup 64 is formed into a tapered cylindrical shape that expands downwards using an elastic material such as rubber.

[0027] Furthermore, as shown in Figures 3 and 4, rubber seals (only one shown in Figures 3 and 4) 68 are fixed to the upper surfaces of the four corners of the plate 63A, through which the shafts 66 are inserted so as to slide vertically. In addition, a flange portion 66b is integrally formed at an intermediate height position on the outer circumference of each shaft 66, and a spring 69 (only one shown in Figures 3 and 4) constituting a biasing means is compressed between this flange portion 66b and the plate 63A.Therefore, as shown in Figures 3 and 4, when each suction cup 64 is in contact with the upper surface of the ring frame F of the work set WS, a force (pressing force) acts on each suction cup 64 in a direction that presses it against the upper surface of the ring frame F due to the weight of each shaft 66 and head 67 and the downward biasing force of the spring 69.

[0028] As shown in Figures 3 and 4, a suction passage 66A is vertically routed through the axial center of each shaft 66, and a communication passage 67A is formed inside the head 67. The lower end of the suction passage 66A opens into the inside of the suction cup 64 as a suction port 66a, and the upper end of the suction passage 66A communicates with the communication passage 67A formed inside the head 67. The suction passages 66A formed in each shaft 66 are connected to a suction source 110 such as a vacuum pump via a suction pipe 101, and an on / off valve (solenoid type switching valve) V is provided in the middle of the suction pipe 101 to connect and disconnect the suction passage 66A to the suction source 110. The on / off valve V and the lifting mechanism 61 are electrically connected to the control unit 100 (see Figure 1), and their respective operations are controlled by the control unit 100.

[0029] Furthermore, the communication passage 67A formed in the head portion 67 opens as multiple inlets 67a on the mounting surface (lower surface) 67b of the head portion 67, and as described later, the mounting surface (lower surface) 67b of the head portion 67 selectively sits on the mounting surface (upper surface) 68a of the rubber seal 68. The rubber seal 68 may also be provided on the mounting surface (lower surface) 67b of the head portion 67.

[0030] (Processing mechanism) As shown in Figure 1, the cutting apparatus 1 according to this embodiment, which is a dual dicer, comprises a processing mechanism 70 consisting of a first cutting unit 71 and a second cutting unit 72 arranged side by side on the left side (-X axis side) of the base 2. These first cutting unit 71 and second cutting unit 72 are arranged opposite each other on both the front and rear sides (-Y axis side and +Y axis side) of an opening 3 that opens on the upper surface of the base 2, and imaging units 73 are attached to these first cutting unit 71 and second cutting unit 72, respectively. Here, each imaging unit 73 images the wafer W held on the holding surface of the chuck table 50 to detect the position of the division line (not shown).

[0031] Furthermore, the first cutting unit 71 and the second cutting unit 72 are capable of vertical movement in the Z-axis direction (cutting feed direction) by a pair of front and rear first and second Z-axis direction movement mechanisms 74, and are also capable of forward and backward movement in the Y-axis direction (indexing feed direction) by a pair of front and rear first and second Y-axis direction movement mechanisms 4. The first cutting unit 71 and the second cutting unit 72 are each provided with a disc-shaped cutting blade 11 (only one is shown in Figure 1) which is rotationally driven by a spindle motor (not shown).

[0032] Here, each of the first and second Z-axis movement mechanisms 74 includes a pair of Z-axis guide rails 75 arranged perpendicularly and parallel to each other in front of and behind a rectangular plate-shaped slider 5, a lifting plate 76 that can move up and down along these Z-axis guide rails 75, a rotatable Z-axis ball screw 77 arranged perpendicularly between the pair of Z-axis guide rails 75, and a forward and reverse-rotating Z-axis servo motor 78 that rotates the Z-axis ball screw 77. The first cutting unit 71 and imaging unit 73 and the second cutting unit 72 and imaging unit 73 are attached to the lower part of each lifting plate 76. Nut members (not shown) are provided protruding from the back surface of each lifting plate 76, and the Z-axis ball screw 77 is screwed into these nut members.

[0033] In the first and second Z-axis movement mechanisms 74 configured as described above, when the Z-axis servo motor 78 is driven and the Z-axis ball screw 77 rotates in forward and reverse directions, the lifting plate 76, which has a nut member (not shown) protruding from it that screws onto the Z-axis ball screw 77, moves up and down along a pair of Z-axis guide rails 75. As a result, the first cutting unit 71 and imaging unit 73 and the second cutting unit 72 and imaging unit 73, which are attached to each lifting plate 76, also move up and down along the Z-axis direction (cutting feed direction).

[0034] Furthermore, the front and rear pair of first and second Y-axis movement mechanisms 4 each include the sliders 5, and these sliders 5 are each movable along the Y-axis along a pair of upper and lower Y-axis guide rails 7 that are arranged parallel to each other along the Y-axis direction (front-to-back direction) on the front of a gate-shaped column 6 erected vertically on the base 2.

[0035] In the front and rear pair of first and second Y-axis movement mechanisms 4, a pair of rotatable Y-axis ball screws 8 are positioned between the upper and lower pair of Y-axis guide rails 7, arranged along the Y-axis direction (front and rear direction). Nut members (not shown), which protrude from the back surfaces of the front and rear pair of sliders 5, are screwed onto these Y-axis ball screws 8. In addition, one axial end of each Y-axis ball screw 8 is connected to a Y-axis servo motor 9 (only one is shown in Figure 1), which is a rotation drive source.

[0036] Therefore, in each of the first and second Y-axis movement mechanisms 4, when the Y-axis servo motor 9 is driven to rotate the Y-axis ball screws 8 in the forward and reverse directions, a pair of front and rear sliders 5, each having a nut member (not shown) protruding from it that screws onto the Y-axis ball screws 8, can move along the Y-axis guide rail 7 in the Y-axis direction (indexing feed direction) together with the lifting plate 76. As a result, the first cutting unit 71 and imaging unit 73 and the second cutting unit 72 and imaging unit 73, each attached to the lifting plate 76, can move along the Y-axis guide rail 7 in the Y-axis direction (indexing feed direction).

[0037] As described above, in the cutting apparatus 1 shown in Figure 1, the chuck table 50 and the wafer W (workset WS) held therein are movable along the X-axis direction (left-right direction), and the first cutting unit 71 and imaging unit 73 and the second cutting unit 72 and imaging unit 73 are movable along the Y-axis direction (front-back direction) and the Z-axis direction (up-down direction), respectively.

[0038] (Spinner cleaning mechanism) The spinner cleaning mechanism 80 is for cleaning the wafer W after machining is complete, and is located on the base 2, rearward and to the right of the opening 3. The spinner cleaning mechanism 80 includes a spinner table 81 that rotates while holding the work set WS (wafer W) by suction, and an injection nozzle (not shown) that sprays cleaning fluid from above onto the work set WS (wafer W) held by suction on the spinner table 81. The spinner table 81 includes a suction section having a suction surface that sucks up tape attached to the wafer over an area equivalent to the wafer, a support surface that supports the lower surface of the ring frame outside the suction section, and a clamp section that grips the ring frame supported by the support surface with centrifugal force due to the rotation of the spinner table.

[0039] (Second transport device) The second transport device 90 suction-holds a workset WS, which includes a wafer W that has undergone predetermined cutting by the first cutting unit 71 and the second cutting unit 72, and transports it from the chuck table 50 to the spinner table 81 of the spinner cleaning mechanism 80. Its basic configuration is the same as that of the first transport device 60.

[0040] In other words, the second transport mechanism 90 can move up and down in the Z-axis direction (vertical direction) by a lifting mechanism (not shown), and can also move horizontally on the XY plane by a moving mechanism (not shown). The second transport device 90 is equipped with an H-shaped transport pad 93 in plan view, attached to the lower end of a vertical rod 92, and suction cups 94 are attached to each of the four corners of the transport pad 93.

[0041] (Control Unit) The control unit 100 includes a CPU (Central Processing Unit) that performs calculations according to a control program, and memory units such as ROM (Read Only Memory) and RAM (Random Access Memory). This control unit 100 controls the cassette lifting mechanism 20, the drawer mechanism 30, the temporary storage mechanism 40, the chuck table 50, the first transport device 60, the processing mechanism 70, the spinner cleaning mechanism 80, and the second transport device 90, respectively.

[0042] [Operation of cutting equipment] Next, the operation of the cutting device 1 configured as described above will be explained.

[0043] During the cutting process on the wafer W, the cassette stage 10 and the cassette 10A placed on it are raised and lowered by the cassette lifting mechanism 20 shown in Figure 1, and the workpiece set WS housed in the cassette 10A is gripped by the gripping part 36 of the extraction mechanism 30 and pulled out in the +Y axis direction. The workpiece set WS pulled out from the cassette 10A is then temporarily placed on a pair of frame guides 41 of the temporary placement mechanism 40.

[0044] Next, the lifting mechanism 61 of the first conveying device 60 is driven, causing the conveying pad 63 to descend. The four suction cups 64 of the conveying pad 63 then make close contact with the upper surface of the ring frame F of the workset WS, which is temporarily placed on a pair of frame guides 41. From this position, each suction cup 64 is connected to the suction source 110. As a result, negative pressure is generated in each suction cup 64, and the workset WS is held in place by the conveying pad 63.

[0045] As described above, when the workpiece set WS is held by the transport pad 63, the transport pad 63 is lifted from the frame guide 41 by a predetermined height together with the workpiece set WS. Then, the spacing adjustment mechanism 42 is driven, and the pair of frame guides 41 are slightly widened in the direction that widens the distance between them (specifically, by an amount large enough for the workpiece set WS to pass between the pair of frame guides 41). From this state, when the transport pad 63 holding the workpiece set WS descends, the workpiece set WS held by the transport pad 63 passes between the pair of frame guides 41 and is handed over to the chuck table 50 waiting below.

[0046] Here, Figure 2(a) shows the state in which the workpiece set WS is held by the four suction cups 64 of the transport pad 63 and transported upward to the chuck table 50. In this state in which the workpiece set WS is held by the four suction cups 64 of the transport pad 63, as shown in Figure 3, the shaft 66 is at its lower limit due to the weight of the shaft 66 and the head 67 and the downward biasing force of the spring 69. As a result, the mounting surface (lower surface) 67b of the head 67 attached to the upper end of the shaft 66 sits on the mounting surface (upper surface) 68a of the rubber seal 68 and closes the inlet 67a of the communication passage 67A. Then, in this state, when the control unit 100 opens the on / off valve V as shown in Figure 3 and connects the suction passage 67A of the shaft 66 to the suction source 110 via the suction pipe 101, negative pressure is generated in each suction cup 64, and this negative pressure causes the workpiece set WS to be held by the four suction cups 64 (only one is shown in Figure 3).

[0047] As shown in Figure 2(a), when the workset WS, which is held by suction on the transport pad 63 by four suction cups 64, moves upward on the chuck table 50, the control unit 100 drives the lifting mechanism 61, causing the transport pad 63 and the workset WS held by it to descend. As shown in Figure 2(b), the workset WS is placed on the holding surface of the chuck table 50, the holding surface is connected to the suction source, the tape is held by suction on the holding surface, the ring frame is clamped by four clamps 51 (only two are shown in Figure 2), and the workset WS is held on the chuck table 50.

[0048] As described above, when the workpiece set WS is transferred to the chuck table 50 and held in the chuck table 50, the control unit 100 drives the lifting mechanism 61 to lower the transport pad 63 relative to the workpiece set WS by a predetermined amount, as shown in Figure 2(c), by detecting the rotation of the ball screw with an encoder, and also closes the on / off valve V to block communication between the suction passage 66A of the shaft 66 and the suction source 110. Then, as shown in detail in Figure 4, the plate 63A and rubber seal 68 of the transport pad 63 move downward relative to the shaft 66, so that the mounting surface (lower surface) 67b of the head 67 attached to the upper end of the shaft 66 separates from the mounting surface (upper surface) 68a of the rubber seal 68, forming a gap δ between them, and air from the atmosphere flows in through this gap δ from the inlet 67a of the head 67 through the communication passage 67A to the suction passage 67A of the shaft 66. In other words, since the inlet 67a of the communication passage 67A formed in the head 67 opens to the atmosphere through a gap δ, the internal pressure of each suction cup 64 is maintained at atmospheric pressure, and the suction force of each suction cup 64 is eliminated.

[0049] Therefore, when the control unit 100 subsequently drives the lifting mechanism 61 to raise the transport pad 63 as shown in Figure 4(d) and separate it from the work set WS, the four clamps 51 (only two are shown in Figure 2) clamp the ring frame F, allowing the four suction cups 64 of the transport pad 63 to easily detach from the upper surface of the ring frame F of the work set WS, thus enabling the transport pad 63 to detach smoothly from the work set WS.

[0050] As described above, in this embodiment, when separating the workset WS, which is being held by the suction cup 64 of the transport pad 63, from the suction cup 64, as shown in Figures 2(b) and 4, the on / off valve V is closed to stop the suction of air into the suction cup 64, and the transport pad 63 is lowered relative to the shaft 66 to form a gap δ between the mounting surface (lower surface) 67b of the head 67 fixed to the upper end of the shaft 66 and the mounting surface (upper surface) 68a of the rubber seal 68. As a result, the inlet 67a of the head 67, which was blocked by the mounting surface (upper surface) 68a of the rubber seal 68, is opened, and air is drawn into the communication passage 67A of the head 67. Therefore, the internal pressure of the suction cup 64 becomes atmospheric pressure, eliminating the suction force of the suction cup 64, and the workset WS can be easily separated from the transport pad 63. In this case, since no air is ejected from the suction cup 64, dust is not scattered into the surroundings, and the adhesion of dust to the upper surface of the wafer W is reliably prevented.

[0051] Note that the suction source 110 may be an ejector instead of a vacuum pump. If an ejector is used, the on / off valve V is not provided. The suction piping 101 is equipped with a check valve that blocks the airflow toward the suction cup 64 and an air valve that supplies or blocks air to the ejector. When detaching the workpiece set WS (ring frame F) from the suction cup 64, the air valve is closed to block the air supplied to the ejector, and the inlet 67a of the head 67 is opened as described above, thereby drawing in atmospheric air into the communication passage 67A of the head 67 and raising the internal pressure of the suction cup 64 to atmospheric pressure.

[0052] Then, when the workset WS is transferred onto the chuck table 50, the chuck table 50 holding the workset WS moves in the direction of the -X axis by an X-axis movement mechanism (not shown).

[0053] On the other hand, in the first cutting unit 71 and the second cutting unit 72 shown in Figure 1, once an image is obtained by imaging the surface of the wafer W with each imaging unit 73, the planned division lines to be cut are detected by pattern matching processing based on the image. Once the planned division lines of the wafer W are detected in this way, the Y-axis positions of each cutting blade 11 of the first cutting unit 71 and the second cutting unit 72 (only one is shown in Figure 1) are determined by a pair of front and rear Y-axis movement mechanisms 4, and the Y-axis positions of these cutting blades 11 are aligned with the positions of the planned division lines to be cut.

[0054] Then, from the above state, the cutting blades 11 of the first cutting unit 71 and the second cutting unit 72 are each driven to rotate at high speed, and are lowered by a predetermined amount by a pair of front and rear Z-axis movement mechanisms 74, while the chuck table 50 and the work set WS (wafer W) held therein are moved in the X-axis direction by an X-axis movement mechanism (not shown). As a result, the wafer W is cut along the division lines by the cutting blades 11 of the first cutting unit 71 and the second cutting unit 72. When this operation is performed for all division lines in one direction, the chuck table 50 and the work set WS held therein are rotated by 90° by a rotation mechanism (not shown), and cutting is similarly performed on the wafer W along the division lines in the other direction that are perpendicular to the division lines that have been cut. When cutting along all division lines of the wafer W is completed, multiple semiconductor chips on which individual devices D (see Figure 1) are mounted are obtained.

[0055] Once the cutting process on the wafer W is completed as described above, the workpiece set WS held on the chuck table 50 is transferred to the second transfer device 90. The workpiece set WS is then transported to the spinner cleaning mechanism 80 while being held in place by four suction cups 94 provided on the transfer pad 93 of the second transfer device 90, and transferred to the spinner table 81 of the spinner cleaning mechanism 80. In the spinner cleaning mechanism 80, the workpiece set WS rotates with the spinner table 81 at a predetermined speed, and the upper surface (cutting surface) of the wafer W, which rotates with the workpiece set WS, is cleaned by a cleaning liquid sprayed from a spray nozzle (not shown), thus completing the series of cutting processes on the wafer W.

[0056] When the second transport device 90 transfers the workpiece set WS to the spinner table 81 of the spinner cleaning mechanism 80, the lower surface of the workpiece set WS (the lower surface of the tape T) is brought into contact with the suction surface of the spinner table 81, the suction surface is connected to the suction source, and the tape T is held in place by suction at the suction surface. At this time, the lower surface of the ring frame F is supported by the ring frame support surface of the spinner table 81. Then, the transport pad 93 is lowered by a predetermined amount using the lifting mechanism, separating the surface to be placed from the mounting surface of the plate and making the internal pressure in the suction path and the suction cup 94 equal to atmospheric pressure. Then, the transport pad 93 is raised, separating the lower surface of the suction cup 94 from the upper surface of the ring frame F. In other words, because the ring frame F is held in place by suction via the tape T through the suction surface of the spinner table 81, even if the entrance is blocked by the mounting surface when the transport pad 93 is raised and the internal pressure of the suction cup 94 becomes negative pressure compared to atmospheric pressure due to the elastic force of the suction cup 94, the ring frame F can be detached from the suction cup 94.

[0057] The above describes the specific configuration and operation of the first conveying device 60, but the second conveying device 90 is configured similarly to the first conveying mechanism 60 and can achieve the same effects and functions as the first conveying mechanism 60.

[0058] In this embodiment, four suction cups 94 are attached to the transport pad 63 of the first transport device 60 and the transport pad 93 of the second transport device 90, respectively, but the number of these suction cups 64,94 can be any number as long as there are three or more.

[0059] Furthermore, although the above describes an embodiment in which the present invention is applied to a wafer transport device provided in a cutting device, the present invention is similarly applicable to transport devices that transport any object other than wafers.

[0060] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the technical idea described in the claims, specification, and drawings. [Explanation of Symbols]

[0061] 1: Cutting device, 2: Base, 3: Opening, 4: First and second Y-axis direction movement mechanism, 5: Slider, 6: Column, 7: Y-axis guide rail, 8: Y-axis ball screw, 9: Y-axis servo motor, 10: Cassette stage, 10A: Cassette, 11: Cutting blade, 20: Cassette lifting mechanism, 21: Guide rail, 22: Ball screw, 23: Servo motor, 30: Pull-out mechanism, 31: Ball screw, 32: Guide rail, 33: Pull-out arm, 33a: Vertical section, 33b: Horizontal section, 34: Servo motor, 35: Bearing, 36: Gripping part, 40: Temporary placement mechanism, 41: Frame guide, 42: Spacing adjustment mechanism, 50: Chuck table, 51: Clamp, 60: First conveying device, 61: Lifting mechanism, 62: Rod, 63: Conveyor pad, 63A: Plate, 64: Suction cup, 65: Arm, 66: Shaft, 66A: Suction path, 66a: Suction port, 66b: Flange, 67: Head, 67A: Connecting passage, 67a: Entrance, 67b: Mounting surface, 68: Rubber seal, 68a: Mounting surface, 69: Spring (biasing means), 70: Processing mechanism, 71: First cutting unit, 72: Second cutting unit, 73: Imaging unit, 74: First and second Z-axis movement mechanism, 75: Z-axis guide rail, 76: Lifting plate, 77: Z-axis ball screw, 78: Z-axis servo motor, 80: Spinner cleaning mechanism, 81: Spinner table, 90: Second conveying device, 92: Rod, 93: Conveying pad, 94: Suction cup, 95: Arm, 100: Control unit, 101: Suction piping, 110: Suction source, D: Device, F: Ring frame, T: Tape, V: On / off valve (valve) W: wafer (object to be held), WS: workset, δ: gap

Claims

1. A conveying device for conveying an object, comprising: a conveying pad that holds the upper surface of the object to be held by suction cups; a lifting mechanism for raising and lowering the conveying pad; a suction source for drawing suction from the suction cups; a valve for disconnecting and disconnecting communication between the suction source and the suction cups; and a control unit, The transport pad comprises a plate connected to the lifting mechanism, a shaft extending vertically and supported by the plate so as to be able to move up and down, with a vertically extending suction passage formed inside, a suction cup positioned at the lower end of the shaft with the lower end of the suction passage opening as a suction port to suction and hold the upper surface of the object to be held, a head positioned at the upper end of the shaft and having a mounting surface that is placed on the mounting surface of the upper surface of the plate by the weight of the shaft, an inlet opening at the mounting surface of the head, and a connecting passage formed inside the head that connects the upper end of the suction passage and the inlet. The control unit is When using the suction cup to hold an object, the transport pad is lowered so that the suction cup contacts the upper surface of the object to be held, and the valve is opened while the inlet is sealed on the mounting surface, thereby connecting the suction port and the suction source. A conveying device that controls the following when separating an object being held by suction from the suction cup: closing the valve and lowering the conveying pad to bring the lower surface of the object to be held into contact with the upper surface of the conveying location, and further lowering the conveying pad to raise the head relative to the plate, separating the object from the mounting surface, opening the inlet that was blocked by the mounting surface, and allowing air to be drawn into the suction passage.

2. The conveying device according to claim 1, further comprising a biasing means for biasing the shaft downward relative to the plate.

3. The object to be held is a workset in which the ring frame and wafer are integrated by attaching tape. The transport device according to claim 1 or 2, wherein the transport pad has three or more suction cups arranged on it.

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