Wafer processing system

Abstract

The present invention provides a wafer processing system that enables smooth transport of the rim portion after separation. [Solution] The wafer processing system performs a cutting process to separate the rim portion 13 connected to the periphery of the wafer body 12 from the wafer body 12. The wafer processing system comprises a processing table 40 having a smaller diameter than the wafer body 12, and a tray 30 having an inner space 35 with a larger diameter than the processing table 40 that can support the rim portion 13. In the wafer processing system, the tray 30 is lowered from a position directly above the processing table 40 to a tray standby position so that the processing table 40 passes through the inner space 35 of the tray 30, and the wafer supported by the tray 30 is supported by the processing table 40. After the cutting process, the tray 30 in the tray standby position is raised, and the rim portion 13 separated from the wafer body 12 is transported by the tray 30.

Description

Technical Field

[0001] The present disclosure relates to a wafer processing system that separates a rim portion connected to the peripheral edge of a wafer body from the wafer body.

Background Art

[0002] Conventionally, for transporting wafers, in order to suppress damage during transportation and the like, a thicker rim portion than the wafer body is provided on the outer peripheral edge of the wafer body provided with various devices such as semiconductor elements and electronic components. This is how such wafer transportation is carried out. For such wafers, before dividing the wafer body into a plurality of chips, a cutting process for separating the rim portion from the wafer body is performed by a wafer processing system such as those described in Patent Documents 1 and 2, for example.

Prior Art Literature

Patent Literature

[0003]

Patent Literature 1

Patent Literature 2

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, in Patent Document 1, sufficient consideration has not been given to the treatment of the rim portion after separation. Further, in Patent Document 2, since the rim portion after separation is conveyed by a dedicated recovery means, there is room for improvement in smoothly conveying the rim portion after separation. This problem is not limited to wafers having a wafer body and a rim portion thicker than the wafer body, but is common to wafer processing systems that separate the rim portion from the wafer body by cutting.

Means for Solving the Problem

[0005] A wafer processing system that solves the above problems processes a wafer having a wafer body and a rim portion connected to the periphery of the wafer body. The wafer processing system comprises a table configured to hold the wafer by suction and having a smaller diameter than the wafer, a tray having an inner space larger in diameter than the table and capable of supporting the rim portion, a transport unit capable of transporting the tray, a processing unit capable of cutting the outer periphery of the wafer body, and a control unit that controls each part of the wafer processing system. The control unit lowers the tray from a position directly above the table to a standby position so that the table passes through the inner space, controls the transport unit so that the wafer supported by the tray is supported by the table, controls the processing unit so that the outer periphery of the wafer body is cut and the rim portion is separated from the wafer body while the wafer is held by suction on the table, raises the tray in the standby position, and controls the transport unit so that the rim portion separated from the wafer body is transported by the tray. [Effects of the Invention]

[0006] According to this disclosure, the rim portion can be smoothly transported after being cut off. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1(a) is a plan view of a wafer to be processed in one embodiment of a wafer processing system, viewed from the surface side; Figure 1(b) is a cross-sectional view of the wafer at 1b-1b; and Figure 1(c) is an enlarged plan view showing the area enclosed by the dashed line 1c. [Figure 2] Figure 2 is a top view showing a schematic configuration of one embodiment of a wafer processing system. [Figure 3] Figure 3(a) is a plan view of a wafer to be processed in one embodiment of the wafer processing system, Figure 3(b) is a cross-sectional view of the wafer at 3b-3b, and Figure 3(c) is an enlarged plan view showing the area enclosed by the dashed line 3c. [Figure 4] Figure 4 is a plan view showing the processing table. [Figure 5] Figure 5 shows the processing table near the tray holding section. [Figure 6] Figure 6 is an explanatory diagram illustrating the operation of the tray holding unit. [Figure 7] Figure 7 is a schematic front view showing the machining area. [Figure 8] Figure 8 is a schematic front view showing the transport unit. [Figure 9] Figure 9 is a schematic bottom view showing the transport base. [Figure 10] Figure 10(a) schematically shows the state in which the tray is held by the tray holding pad, Figure 10(b) schematically shows the state in which the wafer body is held by the wafer holding pad, and Figure 10(c) schematically shows the operation mode of the anti-detachment piece. [Figure 11] Figure 11 is a block diagram showing the schematic configuration of the information processing device that constitutes the control device. [Figure 12] Figure 12 is a functional block diagram showing the schematic configuration of the control device. [Figure 13] Figure 13 is a flowchart showing the processing flow of wafer 10 by the wafer processing system. [Figure 14] Figure 14 is a schematic diagram illustrating a part of the pre-processing transport process, showing how the wafers are placed on the processing table. [Figure 15] Figure 15 is a schematic diagram showing a part of the pre-processing transport process, in which the wafer is placed on the processing table and the tray is supported by the tray support piece. [Figure 16] Figure 16 schematically shows a part of the pre-processing transport process, illustrating how the transport base retracts while the wafer is adsorbed onto the processing table and the tray is held in place by the tray holding piece. [Figure 17] Figure 17 is a top view showing the state in which the first spindle is positioned above the wafer during the processing step. [Figure 18]FIG. 18 is a diagram schematically showing how a wafer is being cut in a processing step. [Figure 19] FIG. 19 is a diagram schematically showing how a transport unit transports a rim portion in a rim transport step. [Figure 20] FIG. 20 is a diagram schematically showing how a transport unit transports a wafer main body in a wafer main body recovery step. [Figure 21] FIG. 21 is a diagram showing an example of a processing table according to a modification. [Figure 22] FIG. 22 is a diagram schematically showing a case where a tray functions as an outer support portion according to a modification. [Figure 23] FIG. 23 is a diagram schematically showing a case where an outer support portion is provided on a processing table according to a modification. DESCRIPTION OF EMBODIMENTS

[0008] An embodiment of a wafer processing system will be described with reference to FIGS. 1 to 20. First, a wafer to be processed by the wafer processing system will be described with reference to FIG. 1. As shown in FIG. 1(a), a wafer 10 to be processed has a perfect circular shape centered on a wafer center 11 in a top view. The wafer 10 includes a wafer main body 12 and a rim portion 13. On the surface side of the wafer main body 12, various devices such as semiconductor elements and electronic components (not shown) are provided in regions partitioned by streets (not shown). The wafer main body 12 is divided into a plurality of chips by being cut along the streets. The rim portion 13 is continuous with the outer peripheral edge of the wafer main body 12. The rim portion 13 is separated from the wafer main body 12 when the wafer 10 is cut along a planned cutting line 15 that extends circumferentially along the outer peripheral portion of the wafer main body 12.

[0009] As shown in Figure 1(b), the rim portion 13 forms a step at the boundary between the wafer body 12 and the back side of the wafer 10. The rim portion 13 has a thickness tb that is greater than the thickness ta of the wafer body 12. The rim portion 13 is a part that is thicker than the wafer body 12 by a thickness difference Δt (=tb-ta). The rim portion 13 increases the rigidity of the wafer 10, thereby suppressing damage to the wafer 10 during transportation and other situations.

[0010] As shown in Figure 1(c), the rim portion 13 is provided with a notch portion 16. The notch portion 16 is formed in a shape that cuts out a part of the outer edge of the rim portion 13. The notch portion 16 is used to position the wafer 10 relative to the tray 30 shown in Figure 3.

[0011] (Overview of the wafer processing system) Refer to Figure 2 to describe the overview of the wafer processing system. As shown in Figure 2, the wafer processing system 20 includes a first cassette 21, a tray 30, a processing table 40, a processing unit 60, a transport unit 80, a cleaning device 97, and a second cassette 98.

[0012] The first cassette 21 is configured to accommodate multiple trays 30. Each tray 30 is configured to accommodate wafers 10 with the rim portion 13 supported. The transport unit 80 is configured to transport the tray 30. The transport unit 80 transports the tray 30 containing the wafers 10 before processing from the first cassette 21 to the processing table 40 located at the transport position. The processing table 40 located at the transport position is shown by a solid line in Figure 2.

[0013] The processing table 40 is configured to hold the wafer 10 by suction. The processing table 40 is configured to fix the tray 30. The processing table 40 is configured to rotate the tray 30 together with the wafer 10 around a table rotation axis 43 that extends in a direction perpendicular to the plane of the paper. The processing table 40 is configured to move between a transport position and a processing position which is directly below the processing unit 60. The processing table 40 in the processing position is shown by a dashed line in Figure 2.

[0014] The processing unit 60, with the processing table 40 positioned at the processing location, performs a cutting process to cut the wafer 10 along the planned cutting line 15 while supplying cutting fluid. After the cutting process, the processing table 40 moves to the transport position.

[0015] After the processing table 40 is moved to the transport position, the transport unit 80 transports the tray 30 held on the processing table 40 to the first cassette 21, and then transports the cut wafer body 12 to the cleaning device 97. The cleaning device 97 is, for example, a spin cleaning device. The cleaning device 97 cleans the processed wafer body 12. After cleaning, the transport unit 80 transports the wafer body 12 from the cleaning device 97 to the second cassette 98. The second cassette 98 is configured to store multiple washed wafer bodies 12.

[0016] The wafer processing system 20 will be described in more detail below with reference to Figures 3 to 20. In the wafer processing system 20, one direction in the horizontal direction is called the X direction, the direction perpendicular to the X direction in the horizontal direction is called the Y direction, and the vertical direction perpendicular to both the X and Y directions is called the Z direction.

[0017] (Tray) As shown in Figure 3(a), the tray 30 has a tray body 31 and a rim support portion 32. In this embodiment, the tray 30 is formed in a ring shape from resin.

[0018] The tray body 31 functions as the outer frame of the tray 30 that accommodates the wafer 10. The tray body 31 constitutes the outer ring portion of the tray 30. The inner diameter of the tray body 31 is formed to be slightly larger than the outer diameter of the wafer 10 so as to suppress the horizontal movement (XY direction) of the wafer 10. The tray body 31 has a suction-receiving portion 33 that is held by the transport unit 80 when the tray 30 is transported, and a fixing piece engagement portion 34 that is held by the tray holding portion 50 (see Figure 4) provided on the processing table 40. The outer edge of the tray body 31 is formed in an arc shape at the suction-receiving portion 33 and in a straight line at the fixing piece engagement portion 34. The suction-receiving portion 33 and the fixing piece engagement portion 34 are provided alternately in the circumferential direction of the tray 30. The suction-receiving portion 33 is provided at a position corresponding to the tray suction pad 90 of the transport unit 80, which will be described later. The fixing piece engagement portion 34 is provided at a position corresponding to the tray holding portion 50 of the processing table 40, which will be described later. The tray 30 is transported such that the straight portion of the fixing piece engagement portion 34 is aligned with the X or Y direction.

[0019] The rim support portion 32 supports the rim portion 13 of the wafer 10 housed in the tray 30. The rim support portion 32 constitutes the inner ring portion of the tray 30. The rim support portion 32 is integrally connected to the inner peripheral edge of the tray body 31. The rim support portion 32 forms the inner space 35 of the tray 30.

[0020] As shown in Figure 3(b), the rim support portion 32 forms a rim support surface 36 at a position lower than the upper surface of the tray body 31 by a storage height h. The inner diameter of the rim support portion 32 is formed to be slightly larger than the outer diameter of the wafer body 12. That is, the rim support portion 32 is formed so that a part of the rim portion 13 is located inside the rim support portion 32.

[0021] As shown in Figure 3(c), the tray 30 has a notch guide portion 37. The notch guide portion 37 is integrally connected to the tray body 31 and the rim support portion 32. The notch guide portion 37 is formed in a shape that protrudes inward from the tray body 31 when viewed from above. The notch guide portion 37 guides the position of the wafer 10 relative to the tray 30 by fitting with the notch portion 16 of the wafer 10. The notch guide portion 37 also positions the wafer 10 relative to the tray 30 and suppresses the rotation of the wafer 10 relative to the tray 30.

[0022] (Processing table) As shown in Figure 2, the processing table 40 is supported by a table movement mechanism 41 extending in the X direction. The table movement mechanism 41 is supported by a main frame (not shown). The table movement mechanism 41 is configured to move the processing table 40 between a transport position and a processing position along a guide rail (not shown) extending in the X direction.

[0023] As shown in Figure 4, the processing table 40 has a holding surface 42 capable of adsorbing and holding the wafer 10, and is configured to rotate around a table rotation axis 43 that extends in the Z direction. The processing table 40 rotates around the table rotation axis 43 when the table rotation mechanism 44 (see Figure 12) is driven.

[0024] The processing table 40 is formed to have a smaller diameter than the wafer 10. More specifically, the processing table 40 is formed to have a smaller diameter than the outer diameter of the wafer body 12 so that the rim portion 13 of the wafer 10 is positioned outside the processing table 40. In addition, the processing table 40 is formed to have a smaller diameter than the inner diameter of the rim support portion 32 of the tray 30.

[0025] The processing table 40 has a cutting groove 46 that opens into the holding surface 42. The cutting groove 46 extends in the circumferential direction around the table rotation axis 43. The cutting groove 46 is positioned to correspond to the planned cutting line 15 of the wafer 10. The cutting groove 46 functions, for example, as a relief area for the blade when cutting the wafer 10 with a blade. In the processing table 40, the area outside the cutting groove 46 relative to the table rotation axis 43 is called the outer support portion 47. The outer support portion 47 is the part that supports the wafer 10 outside the processing area. The processing table 40 may be configured to allow the wafer 10 to be adsorbed at the outer support portion 47. This allows the wafer 10 to be adsorbed on both sides of the cutting groove 46.

[0026] The processing table 40 has a plurality of tray holding sections 50. The tray holding sections 50 are provided at equal intervals in the circumferential direction around the table rotation axis 43. The tray holding sections 50 hold the tray 30 so as to rotate together with the processing table 40. In this embodiment, the processing table 40 has four tray holding sections 50 so as to hold the tray 30 from all four sides.

[0027] As shown in Figure 5, the tray holding unit 50 includes a holding arm 51, a tray support piece 52, a tray fixing piece 54, and a fixing piece operating unit 55. The holding arm 51 has a base end connected to the lower part 48 of the machining table 40. The holding arm 51 extends radially around the table rotation axis 43. In a top view, the holding arm 51 has its tip end on the outside of the machining table 40.

[0028] The tray support piece 52 is provided at the tip of the holding arm 51. The tray support piece 52 supports the tray 30, which has been transported to the processing table 40 by the transport unit 80, with its tray support surface 53. The tray support surface 53 is positioned below the holding surface 42 by a height difference H. The tray support piece 52 is formed such that the height difference H is greater than the sum of the thickness difference Δt in the wafer 10 and the storage height h in the tray 30.

[0029] As shown in Figure 6, the tray fixing piece 54 is shaped to engage with the fixing piece engagement portion 34 of the tray 30. The tray fixing piece 54 is supported by the fixing piece operating portion 55 so as to be rotatable about the fixing piece rotation axis portion 56, which extends in the direction perpendicular to the plane of the paper in Figure 5. The fixing piece operating portion 55 is located on the tip side of the holding arm 51, closer to the tray support piece 52. The fixing piece operating portion 55 rotates the tray fixing piece 54 between a non-fixed position where interference with the tray 30 is avoided and a fixed position where the fixing piece engagement portion 34 of the tray 30 is pressed against the tray support piece 52 with a predetermined force. In the fixed position, the tray fixing piece 54 restricts the displacement of the tray 30 in the horizontal and vertical directions. In Figure 6, the tray fixing piece 54 in the non-fixed position is shown by a solid line, and the tray fixing piece 54 in the fixed position is shown by a dashed line.

[0030] (Processing department) As shown in Figure 7, the machining section 60 includes a first spindle 61, a second spindle 62, and a spindle moving mechanism 70.

[0031] The first spindle 61 has a first rotating shaft portion 63. The first rotating shaft portion 63 is configured to rotate around a first rotation axis 64 extending in the Y direction as its center of rotation, driven by a motor built into the first spindle 61. A first blade 65 is attached to the tip of the first rotating shaft portion 63.

[0032] The second spindle 62 has a second rotating shaft portion 67. The second rotating shaft portion 67 is configured to rotate around a second rotating axis 68 extending in the Y direction as its center of rotation, driven by a motor built into the second spindle 62. A second blade 69 is attached to the tip of the second rotating shaft portion 67.

[0033] The spindle movement mechanism 70 is configured to be movable in the Y direction and the Z direction between the spindles 61 and 62. The spindle moving mechanism 70 has a spindle support frame 71 extending in the Y direction. The spindle support frame 71 is supported by a main frame (not shown). The spindle support frame 71 supports a first moving unit 72 and a second moving unit 73 so as to be movable along a guide rail (not shown) extending in the Y direction.

[0034] The first moving unit 72 includes a first horizontal moving section 74 and a first vertical moving section 75. The first horizontal moving section 74 is supported on a spindle support frame 71 so as to be movable along the Y direction. The first vertical moving section 75 is supported on the first horizontal moving section 74 so as to be movable along a guide rail (not shown) extending in the Z direction. The first spindle 61 is attached to the first vertical moving section 75.

[0035] The second moving unit 73 includes a second horizontal moving section 76 and a second vertical moving section 77. The second horizontal moving section 76 is supported on a spindle support frame 71 so as to be movable along the Y direction. The second vertical moving section 77 is supported on the second horizontal moving section 76 so as to be movable along a guide rail (not shown) extending in the Z direction. The second spindle 62 is attached to the second vertical moving section 77.

[0036] The first moving unit 72 is equipped with an imaging unit 78. The imaging unit 78 is configured to move together with the first spindle 61. The imaging unit 78 images the surface of the wafer 10 held by adsorption on the processing table 40. The imaging unit 78 outputs image data showing the imaged surface of the wafer 10 to a control device 100, which will be described later. The imaging unit 78 is an example of a sensor that detects the position of the wafer 10 held by adsorption on the processing table 40.

[0037] (Transportation section) The transport unit 80 is configured to transport the tray 30 between the first cassette 21 and the processing table 40 located at the transport position. The transport unit 80 is configured to transport the wafer body 12 after cutting from the processing table 40 located at the transport position to the cleaning device 97. The transport unit 80 is configured to transport the wafer body 12 after cleaning from the cleaning device 97 to the second cassette 98.

[0038] As shown in Figure 8, the transport unit 80 has a transport mechanism 81. The transport mechanism 81 includes a transport frame 82, a horizontal transport unit 83, and an up-and-down transport unit 84. In a top view, the transport frame 82 extends in the Y direction between the transport position and the processing position of the processing table 40 in the X direction, as shown in Figure 2. The transport frame 82 is supported by a main frame (not shown). The transport frame 82 supports a horizontal transport section 83 that is movable along a guide rail (not shown) that extends in the Y direction. The horizontal transport section 83 supports the vertical transport section 84.

[0039] The vertical conveying section 84 has a cylinder 85 supported by the horizontal conveying section 83 and a slide rod 86 that can slide in the Z direction relative to the cylinder 85. A support arm 87 (see Figure 2) is connected to the tip of the slide rod 86. In a top view, the support arm 87 extends to the opposite side of the conveying frame 82 in the X direction. A conveying base 88 is connected to the tip of the support arm 87. The conveying base 88 is configured to move along the Y direction above the first cassette 21, the processing table 40 in the conveying position, the cleaning device 97, and the second cassette 98 by the conveying mechanism 81.

[0040] As shown in Figure 9, the lower surface of the transport base 88 is provided with a tray suction pad 90, a wafer holding pad 91, a movement restricting section 92, and a fall prevention section 93. The transport base 88 is also provided with a transport center 89. The transport center 89 is the reference position for controlling the position of the transport base 88.

[0041] The tray suction pads 90 are arranged at equal intervals on concentric circles centered on the transport center 89. The wafer holding pads 91 are arranged inside the transport center 89 compared to the tray suction pads 90. The wafer holding pads 91 are arranged at equal intervals on concentric circles centered on the transport center 89. The movement restricting section 92 is arranged inside the transport center 89 compared to the tray suction pads 90, but outside the wafer holding pads 91. The movement restricting section 92 is arranged at equal intervals on concentric circles centered on the transport center 89.

[0042] The anti-detachment section 93 is located inside the tray suction pad 90 and outside the wafer holding pad 91 relative to the transport center 89. The anti-detachment section 93 is located between the movement restricting sections 92 in the circumferential direction around the transport center 89. The anti-detachment section 93 is located at equal intervals on concentric circles around the transport center 89.

[0043] As shown in Figure 10(a), the tray suction pad 90 is provided at a position corresponding to the suction portion 33 of the tray 30. The tray suction pad 90 is configured to suction and hold the tray 30 on the tray holding surface 90a. The tray suction pad 90 is, for example, a vacuum suction pad.

[0044] As shown in Figure 10(b), the wafer holding pad 91 holds the wafer body 12 after cutting. The wafer holding pad 91 is, for example, a Bernoulli pad. The wafer holding pad 91 has a wafer holding surface 91a that is above the tray holding surface 90a of the tray suction pad 90.

[0045] The movement restricting section 92 restricts the horizontal movement of the wafer body 12 held by the wafer holding pad 91. The movement restricting section 92 has a movement restricting surface 92a. The movement restricting surface 92a is a downward sloping surface that slopes from the inside out. The movement restricting section 92 restricts the movement of the wafer body 12 by causing the edge portion (upper outer peripheral edge) of the wafer body 12 held by the wafer holding pad 91 to come into contact with the movement restricting surface 92a.

[0046] As shown in Figure 10(c), the anti-detachment section 93 prevents the wafer body 12, which is held by the wafer holding pad 91, from falling off. The anti-detachment section 93 has an anti-detachment piece 94 and an anti-detachment piece operating section 95. The base end of the anti-detachment piece 94 is connected to the anti-detachment piece operating section 95. The tip of the anti-detachment piece 94 is bent toward the transport center 89. The anti-detachment piece 94 is configured to be rotatable between a non-operating position shown by a dashed line in Figure 10(c) and an operating position shown by a solid line in Figure 10(c) by the anti-detachment piece operating section 95. The non-operating position is a position where interference with the wafer body 12 is avoided even if the transport base 88 is moved in the Z direction to hold the wafer body 12 with the wafer holding pad 91. The operating position is a position where the tip of the anti-detachment piece 94 is positioned below the wafer body 12, preventing the wafer body 12 from falling off.

[0047] (Control device) A control device that provides overall control of the wafer processing system 20 will be described with reference to Figures 11 and 12.

[0048] As shown in Figure 11, the control device is centered around the information processing device H10. The information processing device H10 includes a communication device H11, an input device H12, an output device H13, a storage device H14, and a processor H15. Note that this hardware configuration is just one example, and it can also be implemented with other hardware.

[0049] Communication device H11 is an interface that establishes a communication path with other devices and performs data transmission and reception, such as a network interface card or a wireless interface.

[0050] Input device H12 is a device that accepts input of various types of information. Input device H12 can be, for example, a touch panel, a mouse, or a keyboard. Output device H13 includes a display and speaker that show various types of information.

[0051] The storage device H14 stores data and programs necessary for executing various functions of the control unit. Examples of storage devices H14 include ROM, RAM, hard disks, and SSDs.

[0052] The processor H15 controls each process using programs and data stored in the memory device H14. Examples of processor H15 include CPUs and MPUs. This processor H15 loads programs stored in ROM or other memory into RAM and executes various instructions corresponding to various processes. For example, when the application program for the wafer processing system 20 is started, the processor H15 executes instructions corresponding to each process described later.

[0053] Processor H15 is not limited to performing software processing for all of the processes it executes. For example, processor H15 may have dedicated hardware circuits (e.g., application-specific integrated circuits: ASICs) that perform hardware processing for at least some of the processes it executes. That is, processor H15 can be configured as a circuit including (1) one or more processors that operate according to a computer program (software), (2) one or more dedicated hardware circuits that perform at least some of the various processes, or (3) a combination thereof. The processor includes a CPU and memory such as RAM and ROM, where memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or non-temporary computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0054] As shown in Figure 12, the control device 100 includes a transport control unit 101, a processing table control unit 102, a spindle control unit 103, an imaging control unit 104, an eccentricity calculation unit 105, and a cleaning control unit 106, which function through the execution of a program.

[0055] The transport control unit 101 controls various operations related to the transport unit 80. Specifically, the transport control unit 101 controls the movement of the transport base 88 by the transport mechanism 81, the operation of the tray suction pad 90, the operation of the wafer holding pad 91, and the operation of the prevention piece operating unit 95.

[0056] The machining table control unit 102 controls various operations related to the machining table 40. Specifically, the machining table control unit 102 controls the movement of the machining table 40 by the table moving mechanism 41, the rotation of the machining table 40 around the table rotation axis 43 as the center of rotation, and the operating state of the fixed piece operating unit 55.

[0057] The spindle control unit 103 controls various operations related to the first spindle 61 and the second spindle 62. Specifically, the spindle control unit 103 controls the movement of the first spindle 61 and the second spindle 62 by the spindle moving mechanism 70, the rotation state of the first rotating shaft portion 63 in the first spindle 61, and the rotation state of the second rotating shaft portion 67 in the second spindle 62.

[0058] The imaging control unit 104 controls the imaging by the imaging unit 78. When the processing table 40 is positioned at the processing position and the first moving unit 72 is positioned at a predetermined imaging position, the imaging control unit 104 causes the imaging unit 78 to image the surface of the wafer 10. The imaging control unit 104 acquires the imaging data captured by the imaging unit 78.

[0059] The eccentricity calculation unit 105 calculates the eccentricity of the wafer center 11 with respect to the table rotation axis 43 of the processing table 40 by processing the image data acquired by the imaging unit 78. The eccentricity consists of a displacement in the X direction and a displacement in the Y direction. Furthermore, the eccentricity is based on the fit tolerance between the notch portion 16 of the wafer 10 and the notch guide portion 37 of the tray 30, and is therefore very small. The cleaning control unit 106 cleans the wafer body 12 by controlling the cleaning device 97.

[0060] (Wafer processing process) Next, with reference to Figures 13 to 20, the processing flow of the wafer 10 by the wafer processing system 20 will be explained.

[0061] As shown in Figure 13, the wafer 10 processing involves the following steps: pre-processing transport (step S101), processing (step S102), rim transport (step S103), and wafer body retrieval (step S104).

[0062] (Pre-processing transport process) The pre-processing transport process (step S101) will be described with reference to Figures 14 to 16. In the pre-processing transport process, the control device 100 performs a pre-processing transport operation to transport the tray 30 stored in the first cassette 21 to the processing table 40. At the start of the pre-processing transport process, the wafers 10 are contained in the tray 30 stored in the first cassette 21, and the processing table 40 is positioned at the transport location.

[0063] In the pre-processing transport process, as shown in Figure 14, the control device 100 moves the transport base 88 to the first cassette 21, and then holds the suction portion 33 of the tray 30 stored in the first cassette 21 with the tray suction pad 90. Then, the control device 100 moves the transport base 88 to a position directly above the processing table 40 so that the table rotation axis 43 of the processing table 40 and the wafer center 11 of the wafer 10 overlap in the Z direction.

[0064] Next, as shown in Figure 15, the control device 100 lowers the transport base 88 to a position where the tray 30 is supported by the tray support piece 52. The position of the tray 30 supported by the tray support piece 52 is called the tray standby position.

[0065] Here, since the inner diameter of the rim support portion 32 is larger than the outer diameter of the processing table 40, the tray 30 is supported by the tray support piece 52 with the processing table 40 positioned in the inner space 35. Also, the height difference H between the tray support surface 53 and the holding surface 42 is greater than the sum of the thickness difference Δt of the wafer 10 and the storage height h of the tray 30. Therefore, the wafer 10 is placed on the holding surface 42 of the processing table 40 before the tray 30 is supported by the tray support piece 52, and the tray 30 is supported by the tray support piece 52 while separated from the wafer 10 placed on the holding surface 42.

[0066] As shown in Figure 16, once the tray 30 is supported by the tray support piece 52, the control device 100 adsorbs the wafer 10 onto the holding surface 42 of the processing table 40. The control device 100 also fixes the tray 30 to the processing table 40 by rotating the tray fixing piece 54 from an unfixed position to a fixed position. Subsequently, the control device 100 retracts the transport base 88 above the processing table 40.

[0067] (Processing process) The processing step (step S102) will be described with reference to Figures 17 and 18. In the processing step, the control device 100 performs a processing operation to cut the wafer 10 along the planned cutting line 15.

[0068] During the processing, the control device 100 moves the processing table 40 from the transport position to the processing position. Then, the control device 100 moves the first moving unit 72 to the imaging position and causes the imaging unit 78 to image the surface of the wafer 10. Based on the imaging data captured by the imaging unit 78, the control device 100 calculates the eccentricity of the wafer center 11 with respect to the table rotation axis 43.

[0069] As shown in Figure 17, the control device 100 adjusts the position of the processing table 40 and the position of the first spindle 61 based on the eccentricity so that the wafer center 11 and the first rotation axis 64 are aligned in the X direction, and the tip of the first blade 65 is positioned above the cutting groove 46.

[0070] Next, as shown in Figure 18, the control device 100 rotates the first blade 65 while moving the first spindle 61 in the Z direction to position it at the cutting position. The cutting position is the position where the tip of the first blade 65 is positioned in the cutting groove 46. During movement to the cutting position, the first blade 65 cuts a portion of the wafer 10 (chopping). During cutting by the first blade 65, the outer part of the wafer 10 is supported by the outer support portion 47 of the processing table 40. Therefore, the wafer 10 can be cut stably. In addition, since the outer support portion 47 is configured to be able to hold the wafer 10 by suction, vibration and movement of the rim portion 13 during cutting can be prevented. As a result, the wafer 10 can be cut more stably.

[0071] Next, the control device 100 rotates the processing table 40 once around the table rotation axis 43 as the center of rotation while rotating the first blade 65. At this time, the control device 100 may gradually increase the rotation speed of the first blade 65 to the target speed. The control device 100 also rotates the processing table 40 at a rotation speed that allows the wafer 10 to be continuously cut by the first blade 65.

[0072] Here, if the wafer center 11 is eccentric with respect to the table rotation axis 43, there is a risk that the cutting line by the first blade 65 will deviate from the planned cutting line 15. Therefore, when the processing table 40 rotates, the control device 100 adjusts the position of the processing table 40 in the X direction and the position of the first spindle 61 in the Y direction according to the rotation angle of the processing table 40, based on the position when it was placed in the processing position. Specifically, based on the amount of eccentricity and the rotation angle of the processing table 40, the control device 100 adjusts the position of the wafer center 11 and the first rotation axis 64 in the X direction so that the tip of the first blade 65 is positioned in the cutting groove 46 and the cutting line by the first blade 65 does not deviate from the planned cutting line 15.

[0073] When the processing table 40 completes one rotation, the wafer 10 is cut along the planned cutting line 15, thereby separating the rim portion 13 from the wafer body 12. When the processing table 40 completes one rotation, the control device 100 retracts the first spindle 61 upward and moves the processing table 40, which is located in the processing position, to the transport position.

[0074] (Rim conveying process) Referring to Figure 19, the rim transport process (step S103) will be described. In the rim transport process, the control device 100 performs a rim transport process to transport the rim portion 13 that has been separated from the wafer body 12.

[0075] In the rim transport process, the control device 100 controls the transport unit 80, etc., so that the rim portion 13, which has been separated from the wafer body 12, is transported on the tray 30. Specifically, the control device 100 moves the transport base 88 to a position directly above the processing table 40, and then lowers the transport base 88 to a position where the tray 30, which is located in the tray standby position, can be picked up by the tray suction pad 90.

[0076] Next, as shown in Figure 19, the control device 100 rotates the tray fixing piece 54 to an unfixed position and the tray 30 is picked up by the tray suction pad 90, and then raises the transport base 88. At this time, the rim portion 13 that has been separated from the wafer body 12 is collected by the tray 30 which rises together with the transport base 88. After that, the control device 100 transports the tray 30 to the first cassette 21, thereby storing the tray 30 with the collected rim portion 13 in the first cassette 21.

[0077] (Wafer body recovery process) Referring to Figure 20, the wafer body retrieval process (step S104) will be described. In the wafer body retrieval process, the control device 100 performs a wafer body retrieval process to retrieve the wafer body 12 from which the rim portion 13 has been separated.

[0078] As shown in Figure 20, in the wafer body retrieval process, the control device 100 moves the transport base 88 to a position directly above the processing table 40, and then lowers the transport base 88 to a position where the wafer body 12 supported by the processing table 40 can be adsorbed by the wafer holding pad 91. Next, the control device 100 releases the adsorption of the wafer body 12 by the processing table 40 and holds the wafer body 12 with the wafer holding pad 91, and then raises the transport base 88. When the transport base 88 is raised, the control device 100 rotates the fall prevention piece 94 to the operating position. When the wafer body 12 is transported by the transport unit 80, its horizontal displacement is restricted by the movement restricting unit 92 as shown in Figure 10(b), and it is prevented from falling by the fall prevention unit 93 as shown in Figure 10(c).

[0079] Subsequently, the control device 100 moves the transport base 88 to transport the wafer body 12 to the cleaning device 97, then sets the wafer body 12 in a predetermined position in the cleaning device 97 and cleans the wafer body 12 using the cleaning device 97.

[0080] The control device 100 then moves the transport base 88 again to hold the cleaned wafer body 12 with the wafer holding pad 91. The control device 100 then transports the wafer body 12 to the second cassette 98, thereby storing the wafer body 12 in the second cassette 98.

[0081] The operation and effects of this embodiment will now be described. (1) In the wafer processing system 20, the control device 100 lowers the tray 30 from a position directly above the processing table 40 to a tray standby position so that the processing table 40 passes through the inner space 35, and controls the transport unit 80 so that the wafer 10 supported by the tray 30 is supported by the processing table 40. Subsequently, the control device 100 controls the processing unit 60 so that the outer periphery of the wafer body 12 is cut and the rim portion 13 is separated from the wafer body 12 while the wafer 10 is held in place by the processing table 40. Then, the control device 100 raises the tray 30 in the tray standby position and controls the transport unit 80 so that the rim portion 13 separated from the wafer body 10 is transported by the tray 30.

[0082] With this configuration, the rim portion 13 separated from the wafer body 12 can be recovered into the tray 30 simply by raising the tray 30. In other words, the rim portion 13 can be recovered during the process of recovering the tray 30. As a result, the recovery of the rim portion 13 can be carried out smoothly, and the time required for the recovery of the rim portion 13 can be shortened. Furthermore, since the transport unit 80 serves as both a means for transporting the tray 30 and a means for recovering the rim portion 13 after separation, the complexity of the wafer processing system 20 is kept to a minimum.

[0083] (2) The tray 30 has a notch guide portion 37 for positioning the wafer 10 and a rim support portion 32 for supporting the rim portion 13. With this configuration, the wafer 10 can be positioned relative to the tray 30 when it is placed in the tray 30. As a result, the wafer 10 can be placed at a desired position on the processing table 40 by transporting the tray 30.

[0084] (3) The processing table 40 has a holding surface 42 that is smaller in diameter than the wafer body 12. The processing table 40 also has an outer support portion 47 that supports the wafer body 12 outside the cutting line 15 during cutting.

[0085] With this configuration, cutting can be performed with both sides of the planned cutting line 15 supported by the processing table 40. This reduces the mechanical load acting on the wafer 10 during cutting compared to, for example, a case where only the inside of the planned cutting line 15 is supported by the processing table 40. As a result, the wafer 10 can be cut stably.

[0086] (4) The tray standby position is a position where the tray 30 is separated from the rim portion 13. With this configuration, fine positional adjustments are not required when placing the tray 30 in the tray standby position, making it easy to place the tray 30 in the tray standby position.

[0087] (5) The wafer processing system 20 includes a first cassette 21 capable of storing the tray 30. The control device 100 controls the transport unit 80 so that the tray 30 containing the wafers 10 is transported from the first cassette 21 to a position directly above the processing table 40. The control device 100 also controls the transport unit 80 so that the tray 30, which has been raised from the tray standby position, is stored in the first cassette 21.

[0088] With this configuration, the rim portion 13, separated from the wafer body 12, is stored in the first cassette 21 together with the tray 30. As a result, the handling of the rim portion 13 can be improved when performing other processing on the rim portion 13 (e.g., disposal).

[0089] (6) The wafer processing system 20 includes a second cassette 98 capable of storing the wafer body 12, which is the wafer 10 after cutting. This configuration makes it possible to improve the handling of the wafer body 12 when performing other processing on the wafer body 12.

[0090] (7) The processing table 40 has a cutting groove 46 at a position corresponding to the planned cutting line 15. With this configuration, the cutting groove 46 can function as a relief for the first blade 65. As a result, the position of the first spindle 61 moving to the cutting position can be easily controlled.

[0091] (8) The wafer processing system 20 includes an imaging unit 78 that images the processing table 40, which is positioned at the processing location, from the imaging position. The control device 100 calculates the eccentricity of the wafer 10 relative to the processing table 40 based on the imaging data, and adjusts the position based on that eccentricity so that the cutting process is carried out along the planned cutting line 15. With this configuration, even if there is a misalignment between the table rotation axis 43 and the wafer center 11, the wafer 10 can be cut along the planned cutting line 15.

[0092] (9) The tray 30 has a rim support portion 32 which is an inner ring portion that is configured to support the rim portion 13 of the wafer 10 and forms an inner space 35, and a tray body 31 which is an outer ring portion that is connected to the rim support portion 32 and arranged to surround the rim portion 13 of the wafer 10. With this configuration, the rigidity of the tray 30 can be increased.

[0093] (10) As a method of cutting the wafer 10 along the planned cutting line 15, one method is to attach dicing tape to the back surface of the wafer 10 so that it is positioned between the processing table 40 and the wafer 10 before cutting. However, in this method, stress is generated in the wafer 10 due to the tension of the dicing tape. This stress is large at the boundary between the wafer body 12 and the rim portion 13, so there was a risk that the wafer 10 would be damaged during cutting or that the wafer body 12 would be damaged after cutting. In contrast, the wafer processing system 20 cuts the wafer 10 without using dicing tape. As a result, damage caused by the tension of the dicing tape can be prevented.

[0094] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. The processing table 40 does not necessarily have to be provided with a cutting groove 46. In such a configuration, for example, as shown in Figure 21, the processing table 40 is configured to have its outer edge located inside the planned cutting line 15.

[0095] The wafer processing system 20 may have an outer support portion that supports the wafer 10 outside the processing area and supports the rim portion 13 of the wafer 10. Specifically, as shown in Figure 22, for example, the rim support portion 32 of the tray 30 may function as an outer support portion. That is, the tray 30 may support the rim portion 13 in the tray standby position. The rim support portion 32 may be provided with a holding mechanism that holds the rim portion 13 by suction. This prevents vibration and movement of the rim portion 13 during cutting.

[0096] Alternatively, as shown in Figure 23, for example, an outer support portion 49 may be provided on the processing table 40 to support the rim portion 13 of the wafer 10. The outer support portion 49 has a rim support surface 49a located below the holding surface 42 by a thickness difference Δt of the wafer 10. Even with this configuration, the wafer 10 can be cut stably. Furthermore, the outer support portion can be easily installed compared to a configuration where the tray 30 supports the rim portion 13 in the tray standby position. The outer support portion 49 may be provided with a holding mechanism that holds the rim portion 13 by suction. This prevents vibration and movement of the rim portion 13 during cutting.

[0097] The control device 100 may appropriately adjust the rotation speed of the processing table 40 while it is rotating. For example, the control device 100 may control the rotation speed of the processing table 40 so as to gradually decrease it a little before the cutting process is completed. With this configuration, defects that are likely to occur in the wafer body 12 when the cutting process is completed (e.g., chipping) can be reduced.

[0098] In the processing step, the wafer 10 may be cut by rotating the processing table 40 multiple times and gradually cutting the wafer 10. Specifically, for example, a notch may be formed in the wafer 10 along the planned cutting line 15 during the first rotation of the processing table 40, and the wafer 10 may be cut by cutting the notched portion during the second rotation of the processing table 40. With this configuration, it is also possible to cut the wafer 10 using a blade thinner than the blade that formed the notch, so that the stress generated in the wafer 10 when cutting the notched portion is small.

[0099] The tray 30 only needs to be capable of accommodating wafers 10 with the support of the rim portion 13 and have an inner space 35 through which the processing table 40 can pass. Therefore, the shape of the tray 30 is not limited to a ring shape. For example, the tray 30 may have a U-shape with a portion open when viewed from above.

[0100] In the wafer processing system 20, the processing table 40 moves in the X direction and the first spindle 61 moves in the Y direction, thereby causing the processing table 40 and the first spindle 61 to move relative to each other in the horizontal direction. In the wafer processing system 20, it is sufficient for the processing table 40 and the first spindle 61 to move relative to each other in the horizontal direction; for example, both the processing table 40 and the first spindle 61 may be movable in the X and Y directions.

[0101] The wafer 10 may be cut with a glass support positioned in the recess formed by the rim portion 13 to support the wafer body 12. The wafer 10 may be separated from the wafer body 12 by cutting using a laser beam, rather than a blade. This configuration allows for an additional increase in the rigidity of the wafer body 12, thereby reducing damage to the wafer body 12 during the cutting process.

[0102] The wafer 10 to be processed is not limited to having a wafer body 12 and a rim portion 13 that is thicker than the wafer body 12; it is sufficient if the rim portion 13 is separated from the wafer body 12. Therefore, the wafer 10 may, for example, have a wafer body 12 thickness equal to a rim portion 13 thickness. [Explanation of Symbols]

[0103] H10...Information processing device, H11...Communication device, H12...Input device, H13...Output device, H14...Storage device, H15...Processor, 10...Wafer, 11...Wafer center, 12...Wafer body, 13...Rim, 15...Cutting line, 16...Notch, 20...Wafer processing system, 21...First cassette, 30...Tray, 31...Tray body, 32...Rim support part, 33...Adsorption part, 34...Fixing piece engagement part, 35...Inner space, 36...Rim support surface, 37...Notch guide part, 40...Processing Table, 41...Table moving mechanism, 42...Holding surface, 43...Table rotation axis, 44...Table rotation mechanism, 46...Cutting groove, 47...Outer support part, 48...Table lower part, 49...Outer support part, 49a...Rim support surface, 50...Tray holding part, 51...Holding arm, 52...Tray support piece, 53...Tray support surface, 54...Tray fixing piece, 55...Fixing piece operating part, 56...Fixing piece rotation axis part, 60...Processing part, 61...First spindle, 62...Second spindle, 63...First rotation axis part, 64...First rotation axis, 65...First blade, 67...Second rotating shaft section, 68...Second rotating axis, 69...Second blade, 70...Spindle moving mechanism, 71...Spindle support frame, 72...First moving unit, 73...Second moving unit, 74...First horizontal moving section, 75...First vertical moving section, 76...Second horizontal moving section, 77...Second vertical moving section, 78...Imaging unit, 80...Transport section, 81...Transport mechanism, 82...Transport frame, 83...Horizontal transport section, 84...Vertical transport section, 85...Cylinder, 86...Slide rod, 87...Support 88...Holding arm, 89...Transport base, 90...Transport center, 90...Tray suction pad, 90a...Tray holding surface, 91...Wafer holding pad, 91a...Wafer holding surface, 92...Movement restricting part, 92a...Movement restricting surface, 93...Detachment prevention part, 94...Detachment prevention piece, 95...Prevention piece operating part, 97...Cleaning device, 98...Second cassette, 100...Control device, 101...Transportation control unit, 102...Processing table control unit, 103...Spindle control unit, 104...Imaging control unit, 105...Eccentricity calculation unit, 106...Cleaning control unit.

Claims

1. A wafer processing system for processing a wafer having a wafer body and a rim portion connected to the periphery of the wafer body, A table having a smaller diameter than the wafer is configured to hold the wafer by adsorption, A tray having an inner space with a larger diameter than the table and capable of supporting the rim portion, A transport unit capable of transporting the aforementioned tray, A processing unit capable of cutting the outer periphery of the wafer body, The wafer processing system includes a control unit that controls each part of the wafer processing system, The control unit, The tray is lowered from a position directly above the table to a standby position so that the table passes through the inner space, and the transport unit is controlled so that the wafers supported on the tray are supported on the table. The processing unit is controlled so that the outer periphery of the wafer body is cut and the rim portion is separated from the wafer body while the wafer is held in place by adsorption on the table. The tray in the standby position is raised, and the transport unit is controlled so that the rim portion separated from the wafer body is transported on the tray. Wafer processing system.

2. The aforementioned tray is The system has a guide portion for positioning the wafer and a rim support portion for supporting the rim portion. The wafer processing system according to claim 1.

3. The table has a surface for holding the wafer body, which has a smaller diameter than the wafer body. The wafer processing system further includes a support portion on the outside of the holding surface that supports the rim portion during cutting by the processing unit. The wafer processing system according to claim 1.

4. When the tray is in the standby position, the rim portion is separated from the tray. The wafer processing system according to claim 1.

5. The system further comprises a first cassette capable of storing the aforementioned tray, The control unit, The transport unit is controlled so that the tray supporting the wafer is transported from the first cassette to the position directly above it, The transport unit is controlled so that the tray, which has been raised from the standby position, is stored in the first cassette. The wafer processing system according to claim 1.

6. The system further comprises a second cassette capable of storing the wafer body from which the rim portion has been separated. The wafer processing system according to claim 1.

7. The processing unit is configured to cut the outer periphery of the wafer body using a blade. A wafer processing system according to any one of claims 1 to 6.

8. The table has grooves at positions corresponding to the planned cutting lines. The wafer processing system according to claim 7.

Images