Scribing apparatus and edge trimming method for scribing apparatus

Abstract

The present invention aims to provide a dicing device capable of performing high-precision trimming of a workpiece provided with devices. The dicing device includes a chuck table, a rotary table, a microscope, a displacement sensor, a cutting portion, and a control portion that controls movement of the chuck table, the rotary table, the microscope, and the displacement sensor based on measurement results of the microscope and the displacement sensor. The workpiece has a plurality of devices, and the plurality of devices are arranged in a region of the workpiece that is divided by a plurality of first groove portions extending in an X direction and a plurality of second groove portions extending in a Y direction. The control portion is configured to, for a specific portion of a prescribed device among the devices of the workpiece that is located on an outer side in a radial direction centered on a Z axis, acquire workpiece position information, which is information about a position in a normal direction at a circumferential direction position centered on the Z axis, based on a measurement result of the displacement sensor, over an entire circumference, and cause a blade to cut a step portion recessed in a Z direction at an outer circumferential portion of the workpiece based on the acquired workpiece position information.

Description

Technical Field

[0001] This invention relates to a dicing apparatus and a trimming method for the dicing apparatus. This application claims priority based on Japanese Patent Application No. 2024-057188, filed on March 29, 2024, the contents of which are incorporated herein by reference. Background Technology

[0002] A dicing apparatus for dividing workpieces such as wafers containing semiconductor elements or electronic components into individual chips includes: a cutting blade that rotates at high speed by a spindle, a chuck table that holds the workpiece in place, and X, Y, Z, and θ drive units that change the relative position between the chuck table and the cutting blade. This dicing apparatus performs dicing (cutting) by moving the cutting blade relative to the workpiece through the drive units while the cutting blade cuts into the workpiece.

[0003] When thinning workpieces such as wafers, edge chipping can occur due to the influence of the radius (R) shape of the outer periphery, leading to workpiece cracks. To prevent workpiece cracking, a trimming process is performed, which involves pre-removing the radius (R) shape of the outer periphery that causes edge chipping using a cutting tool.

[0004] For workpieces that have undergone edge trimming, a microscope is used to measure the position of the edge portion in the XY plane at three or more points. Based on the positional relationship of the measurements, the trimming width, the center position of the inner portion formed by the trimming process, the inner diameter, etc., are measured. In order to measure the position of the surface of the trimmed workpiece in the Z direction, Patent Document 1 discloses a method for measuring from its focal position using a microscope and a method for measuring based on the step profile obtained using a white light interference microscope.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-125592

[0006] However, white light interference microscopes have the problem of narrow field of view and time-consuming measurement due to the need to scan along the depth direction.

[0007] Furthermore, when measuring the Z-direction position of the workpiece surface, for example, with the chuck stage fixed, the displacement sensor moves to perform the measurement. Since the chuck stage sometimes has a Z-direction position change in its rotational component, the measurement of the Z-direction position of the workpiece surface will include errors from the rotational component, which may result in problems where the specified trimming depth cannot be achieved. Summary of the Invention

[0008] The present invention was made in consideration of the above circumstances, and its purpose is to provide a dicing device and a trimming method for the dicing device, which can perform high-precision trimming processing on workpieces equipped with devices.

[0009] The present invention has the following technical solution.

[0010] A dicing apparatus includes: a suction cup stage that holds a workpiece with a holding surface and is movable in the X direction; a rotary stage for rotating the suction cup stage about a Z-axis; a microscope that is movable in the Y direction and can observe the workpiece; a displacement sensor that is movable in the Y direction and is used to measure the position of the workpiece in the normal direction; a cutting unit including a cutting blade for cutting the workpiece held by the suction cup stage and a spindle for rotating the cutting blade about a rotation axis orthogonal to the normal direction; and a control unit configured to control the movement of the suction cup stage, the rotary stage, the microscope, and the displacement sensor based on the measurement results of the microscope and the displacement sensor. The workpiece has multiple devices arranged in a region defined by multiple first grooves extending along the X direction and multiple second grooves extending along the Y direction. The control unit is configured to: acquire workpiece position information throughout the entire circumference based on the measurement results of the displacement sensor for a specific location of a predetermined device located radially outward about the Z-axis, the workpiece position information being information about the position in the normal direction at a circumferential position centered on the Z-axis; and based on the acquired workpiece position information, cause the cutting blade to cut a stepped portion recessed along the Z-direction on the outer periphery of the workpiece.

[0011] In addition, the present invention has the following technical solution.

[0012] A trimming method using a dicing apparatus, the dicing apparatus comprising: a suction cup stage that holds a workpiece with a holding surface and is movable in the X direction; a rotary stage for rotating the suction cup stage about a Z-axis; a microscope movable in the Y direction and capable of observing the workpiece; a displacement sensor movable in the Y direction and for measuring the position of the workpiece in the normal direction; a cutting unit including a cutting blade for cutting the workpiece held by the suction cup stage and a spindle for rotating the cutting blade about a rotation axis orthogonal to the normal direction; and a control unit configured to control the suction cup stage, the rotary stage, the microscope, and the displacement sensor based on measurement results from the microscope and the displacement sensor. The trimming method, involving the movement of a sensor, includes: preparing a workpiece having multiple devices arranged within a region defined by multiple first grooves extending along the X direction and multiple second grooves extending along the Y direction; acquiring workpiece position information throughout the circumference based on measurements from the displacement sensor for a specific portion of one of the devices on the workpiece that is radially outer of the Z-axis, the workpiece position information being information about the position of the workpiece in the normal direction at a circumferential position centered on the Z-axis; and, based on the acquired workpiece position information, causing a cutting tool to cut a stepped portion recessed along the Z-direction on the outer periphery of the workpiece.

[0013] According to the present invention, a dicing apparatus and a dicing method for performing high-precision trimming of workpieces equipped with devices can be provided. Attached Figure Description

[0014] Figure 1 This is a perspective view of a dicing apparatus according to an embodiment of the present invention.

[0015] Figure 2 This is the control block diagram of the dicing device.

[0016] Figure 3 It is a top view of a workpiece having a device, a first groove, and a second groove.

[0017] Figure 4 This is a side view showing the workpiece during trimming.

[0018] Figure 5 It is a partial sectional view of a workpiece that has undergone trimming.

[0019] Figure 6 This is a diagram illustrating the steps involved in obtaining workbench position information.

[0020] Figure 7 It is a magnified view of a portion of the area surrounding the device.

[0021] Figure 8 This is a graph showing the relationship between the position of the holding surface in the θ direction and the cutting height of the cutting tool.

[0022] Figure 9 This is a graph showing the relationship between the position of the workpiece surface in the θ direction and the cutting height of the cutting tool.

[0023] Figure 10 It is a graph showing the relationship between the position of the workpiece surface in the θ direction, the cutting height of the cutting tool during the first trimming process, and the cutting height of the cutting tool during the second trimming process.

[0024] Figure 11 This is a diagram illustrating the steps for obtaining the position information of the step section.

[0025] Figure 12 It is a top view of the workpiece after trimming. Detailed Implementation

[0026] Below, refer to Figures 1 to 11 Embodiments of the dicing apparatus and the trimming method of the dicing apparatus of the present invention will be described.

[0027] Furthermore, the following embodiments only illustrate one technical solution of the present invention and are not intended to limit the present invention. Any modifications can be made within the scope of the technical concept of the present invention. In addition, in the following drawings, the actual structures differ from each other in scale, quantity, etc., in order to facilitate understanding of the structures.

[0028] Figure 1 This is a perspective view showing the main structural components of the dicing apparatus 10 according to an embodiment of the present invention. Furthermore, the dicing apparatus 10 is described using a three-dimensional coordinate system of X, Y, and Z. The Z direction is the direction in which the normal H of the suction cup stage 42 extends (normal direction). The X direction is the direction orthogonal to the Z direction. The Y direction is the direction orthogonal to both the Z and X directions. Additionally, the rotary stage 40, described later, rotates about an axis H extending along the Z direction, and the circumferential direction centered on the axis H is defined as the θ direction.

[0029] like Figure 1 As shown, the dicing apparatus 10 includes a processing unit 16 for processing a workpiece W, and a control unit CONT for uniformly controlling the actions of each part of the dicing apparatus 10. An example of the workpiece W is a silicon wafer.

[0030] The dicing device 10 may also have a structure that includes a storage section for storing workpiece W, a placement section for temporarily placing workpiece W, and a cleaning section for cleaning workpiece W.

[0031] The machining unit 16 includes: an X-carriage 32, a suction cup worktable 42, a Y-base 44, a Y-carriage (first drive unit) 46A, a Y-carriage (second drive unit) 46B, Z-carriages 50A and 50B, cutting units 51A and 51B, a microscope 60, and a displacement sensor 70.

[0032] The X-carriage 32 is mounted on the X-base 34 and can be guided and moved along the X-direction by X-guide rails 36, 36 extending along the X-direction. The X-carriage 32 is driven by a linear motor 38 along the X-direction indicated by arrow XX. Furthermore, a rotary table 40 rotating along the θ-direction is fixed to the upper surface of the X-carriage 32, and a suction cup table 42 for adsorbing and holding the workpiece W is mounted on this rotary table 40. Therefore, the suction cup table 42 moves along the X-direction via the X-carriage 32 and rotates along the θ-direction via the rotary table 40.

[0033] Y-base 44 is constructed as a portal frame spanning X-base 34. Y-carriages 46A and 46B are provided on the wall of Y-base 44. Y-carriages 46A and 46B are guided by Y-rails 48 and 48 fixed to the wall of Y-base 44 and driven by a drive device consisting of a stepper motor and a ball screw (not shown), thereby enabling them to move independently of each other in the Y direction indicated by arrow YY.

[0034] Z-carrier 50A is mounted on Y-carrier 46A. Z-carrier 50A is guided by a Z-guide rail (not shown) mounted on Y-carrier 46A and driven in the Z direction indicated by arrow ZZ by a drive device consisting of a stepper motor and a ball screw (not shown).

[0035] Z-carrier 50B is mounted on Y-carrier 46B. Z-carrier 50B is guided by a Z-rail (not shown) mounted on Y-carrier 46B and is driven independently of Z-carrier 50A in the Z direction indicated by arrow ZZ by a drive device consisting of a stepper motor and a ball screw (not shown).

[0036] Cutting section 51A is mounted on Z carriage 50A. Cutting section 51B is mounted on Z carriage 50B. Cutting sections 51A and 51B each have a spindle 52 and a cutting insert 54. The spindle 52 causes the cutting insert 54 to rotate at high speed about a rotation axis 53 extending in the Y direction.

[0037] The spindle 52 is fixed opposite to the Z-carriages 50A and 50B. The blade 54 is mounted on the front end of the spindle 52 and is positioned opposite it. The spindle 52 and the blade 54 can move along the Z direction via the drive of the Z-carriages 50A and 50B. The spindle 52 and the blade 54 can move along the Y direction via the drive of the Y-carriages 46A and 46B and the Z-carriages 50A and 50B.

[0038] Microscope 60 is mounted on Z-slide 50A. Microscope 60 is mounted on Y-slide 46A via Z-slide 50A. Microscope 60 can move in the Z direction by being driven by Z-slide 50A. Microscope 60 can move in the Y direction by being driven by both Y-slide 46A and Z-slide 50A.

[0039] Microscope 60 can observe the workpiece W held by the suction cup stage 42. Microscope 60 captures (observes) an image of the surface of the workpiece W held by the suction cup stage 42. Microscope 60 has a camera 61. Microscope 60 captures an image of the surface of the workpiece W through camera 61. The position of microscope 60 and camera 61 in the Y direction is the same as the position of blade 54 set in the Z carriage 50A in the Y direction.

[0040] The camera 61 may be equipped with an imaging element of type CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). The captured image information is output to the control unit CONT. In addition, the microscope 60 may include an imaging system such as a white light interference microscope, in addition to an alignment microscope for alignment.

[0041] Displacement sensor 70 is mounted on Z-carriage 50B. Displacement sensor 70 is mounted on Y-carriage 46B via Z-carriage 50B. Displacement sensor 70 can move along the Z direction via Z-carriage 50B. Displacement sensor 70 can move along the Y direction via Y-carriage 46B and Z-carriage 50B. The position of displacement sensor 70 in the Y direction is the same as the position of the blade 54 mounted on Z-carriage 50B in the Y direction.

[0042] One example of the displacement sensor 70 includes an SLD (Super luminescent diode) light source that emits measurement light, a diffractive optical element, and the aforementioned imaging element. The displacement sensor 70 measures the position of the workpiece W in the Z direction by receiving the reflected light from the measurement light irradiated onto the workpiece W. The measured position in the Z direction is output to the control unit CONT.

[0043] The displacement sensor 70 illuminates a measuring light from a position approximately 10 mm away from the workpiece W to a range of tens of μm (e.g., 40 μm) in diameter on the surface of the workpiece W, and measures the shortest distance within the illuminated range. Therefore, even if the surface of the workpiece W has irregularities, accurate height can be measured. Furthermore, because the measuring light is illuminated from a position approximately 10 mm away from the workpiece W, high-precision measurements can be performed without interference with protrusions such as bumps on the surface of the workpiece W, even if such protrusions are formed.

[0044] The hardware of the control unit (CONT) is suitable for computers.

[0045] Figure 2 This is a control block diagram of the dicing device 10.

[0046] like Figure 2 As shown, the control unit CONT controls the drive of the linear motor 38, thereby moving the X-carrier 32 along the X direction. The control unit CONT moves the X-carrier 32 along the X direction, thereby moving the suction cup stage 42 along the X direction. The control unit CONT controls the rotation drive of the rotary stage 40 in the θ direction. The control unit CONT rotates the rotary stage 40 along the θ direction, thereby rotating the suction cup stage 42 along the θ direction.

[0047] The control unit CONT controls the drive of the Z-slide 50A, thereby moving the microscope 60, camera 61, spindle 52, and blade 54 along the Z direction. The control unit CONT controls the drive of the Y-slide 46A, thereby moving the microscope 60, camera 61, spindle 52, and blade 54 along the Y direction via the Z-slide 50A.

[0048] The control unit CONT moves the displacement sensor 70, spindle 52, and blade 54 along the Z direction by controlling the drive of the Z carriage 50A. The control unit CONT moves the displacement sensor 70, spindle 52, and blade 54 along the Y direction via the Z carriage 50B by controlling the drive of the Y carriage 46B.

[0049] The image information captured by camera 61 is input to the control unit CONT. The control unit CONT performs image processing on the input image information to calculate and obtain the position information of workpiece W (suction cup stage 42) in the X and Y directions.

[0050] The control unit CONT controls the drive of the linear motor 38 based on the acquired position information of the workpiece W (suction cup stage 42), thereby controlling the position of the workpiece W (suction cup stage 42) in the X direction. The control unit CONT also controls the drive of the rotary stage 40 based on the acquired position information of the workpiece W (suction cup stage 42), thereby controlling the position of the workpiece W (suction cup stage 42) in the θ direction.

[0051] The control unit CONT controls the drive of the Y-carriage 46A based on the acquired position information of the workpiece W (suction cup stage 42), thereby controlling the positions of the microscope 60, camera 61, spindle 52, and blade 54 in the Y direction. The control unit CONT also controls the drive of the Y-carriage 46B based on the acquired position information of the workpiece W (suction cup stage 42) and the relative positional relationship between the Y-carriage 46A and Y-carriage 46B in the Y direction, thereby controlling the positions of the displacement sensor 70, spindle 52, and blade 54 in the Y direction.

[0052] The control unit CONT controls the drive of the Z carriages 50A and 50B based on the position of the workpiece W in the Z direction measured by the displacement sensor 70, thereby controlling the cutting feed amount of the blade 54 to the workpiece W in the Z direction.

[0053] With the structure of the machining unit 16 described above, the rotary table 40 can be driven based on the acquired position information of the workpiece W to adjust the position of the workpiece W in the θ direction for alignment. The cutting tool 54 is indexed and fed in the Y direction by the Y slides 46A and 46B, and simultaneously fed in the Z direction by the Z slides 50A and 50B. The chuck table 42 is fed in the X direction by the linear motor 38 and the rotary table 40 and rotates in the θ direction.

[0054] Figure 3 It is a top view of a workpiece W having a device C, a first groove S1, and a second groove S2.

[0055] like Figure 3 As shown, through the operation of the aforementioned processing unit 16 and the rotating blade 54, checkerboard-shaped first grooves S1 and second grooves S2 are machined on the surface Wa of the workpiece W. The first grooves S1 extend along the X direction and are spaced apart in the Y direction, and the second grooves S2 extend along the Y direction and are spaced apart in the X direction, thereby giving the workpiece W multiple monolithic chips that serve as devices C. Multiple devices C are arranged within the areas divided by the first grooves S1 and the second grooves S2. For example, device C is a semiconductor chip.

[0056] After the workpiece W (device C) undergoes edge trimming of its outer periphery, it is monolithically formed by grinding from the back side to the first groove S1 and the second groove S2.

[0057] The trimming method of the dicing device 10 in this embodiment includes: preparing a workpiece W having a plurality of devices C, the plurality of devices C being arranged in an area divided by a plurality of first groove portions S1 extending along the X direction and a plurality of second groove portions S2 extending along the Y direction; acquiring workpiece position information throughout the entire circumference based on the measurement results of a displacement sensor 70 for a specific portion of a predetermined device C located radially outward about the Z-axis among the devices C of the workpiece W; the workpiece position information being information about the normal direction position of the workpiece W in the circumferential direction centered on the Z-axis; and, based on the acquired workpiece position information, causing the cutting tool 54 to cut a step portion Wb recessed along the Z-direction in the outer periphery of the workpiece W. A detailed description will follow.

[0058] During the trimming process, in the machining section 16, the blade 54 mounted on the Y carriage 46A cuts into the workpiece W at a position set based on the X and Y directions of the workpiece W when the Z-direction position is measured by the displacement sensor 70.

[0059] In addition, in the machining section 16, in order to prevent edge chipping, a trimming process is performed to remove the R-shape of the outer periphery of the workpiece W in advance by means of the cutting blade 54.

[0060] Specifically, such as Figure 4 As shown, with the back side of the workpiece W held by the holding surface 42a of the suction table 42, the blade 54, driven by the spindle 52, descends from above the workpiece W to a predetermined height, which reaches a predetermined finishing depth D, thereby cutting into the workpiece W from the surface Wa side. The workpiece W is then rotated in the θ direction by the rotating table 40, thereby removing the chamfered portion 5, which is equivalent to the finishing depth D.

[0061] Furthermore, in the trimming process, the cutting tool 54, which has descended to a predetermined height to reach the finishing depth D, can be moved toward the workpiece W in the Y direction (radial) to cut into the workpiece W, and the workpiece W can be rotated in the θ direction by rotating the worktable 40, thereby removing the chamfered portion 5. Alternatively, the cutting tool 54, which has descended to a predetermined height to reach the finishing depth D, can be moved toward the workpiece W in the X direction (tangential direction) to cut into the workpiece W, and the workpiece W can be rotated in the θ direction by rotating the worktable 40, thereby removing the chamfered portion 5.

[0062] Therefore, as Figure 5 As shown, a stepped portion Wb is formed on the outer periphery of the workpiece W, recessed to a depth D from the surface Wa downwards and with a trimming width of L. By forming the stepped portion Wb on the workpiece W, an inner circular region Wc is formed inside the stepped portion Wb, whose outer diameter (inner diameter of the stepped portion Wb) R1, when viewed from the Z direction, is smaller than the outer diameter R2 of the workpiece W. That is, the boundary between the inner region Wc and the stepped portion Wb, as well as the outer shape Wd of the workpiece W, are circular when viewed from the Z direction.

[0063] In the trimming process of this embodiment, before trimming, error information of the rotation component of the chuck table 42 (Z-direction displacement caused by rotation) and workpiece position information of the rotation component of the workpiece W held by the chuck table 42 (Z-direction displacement caused by rotation) are acquired in advance. Based on the acquired workpiece position information and workpiece position information, the control unit CONT acquires the cutting amount of the workpiece W at the θ-direction position. During trimming, the control unit CONT rotates the workpiece W while moving the insert 54 in the Z-direction according to the θ-direction position of the insert 54 and the acquired cutting amount, and forms a step portion Wb with a finishing depth D.

[0064] [First Implementation Method of Trimming Process]

[0065] The first embodiment of the trimming process, in which the step portion Wb is formed by cutting with the blade 54 and finishing depth D, will be described in detail below.

[0066] [Error in obtaining the rotational component of the suction cup stage 42]

[0067] Figure 6 This is a diagram illustrating the steps involved in obtaining workbench position information.

[0068] like Figure 6 As shown, the control unit CONT directs the measuring light 71 to the holding surface 42a of the chuck stage 42, which is not holding the workpiece W, and simultaneously rotates the chuck stage 42 in the θ direction by rotating the stage 40. The position of the holding surface 42a illuminating the measuring light 71 is preferably a radial position centered on the axis H where the step portion Wb is formed when holding the workpiece W.

[0069] The control unit CONT acquires the table position information throughout the entire circumference. This table position information is obtained by correlating the Z-direction position of the holding surface 42a measured by the displacement sensor 70 with the θ-direction position measured at that Z-direction position. That is, based on the measurement results of the displacement sensor 70, the control unit CONT acquires the table position information regarding the Z-direction position of the holding surface 42a at the θ-direction position throughout the entire circumference as error information for the rotational component of the suction cup table 42.

[0070] [The error in obtaining the rotational component of workpiece W]

[0071] like Figure 3 As shown, the control unit CONT measures the X-axis and Y-axis coordinates of specific locations F of all devices C located radially outward from the axis H and close to the outer peripheral surface of the workpiece W among the multiple devices C in the aligned workpiece W using a microscope 60. A specific location F of a device C can be, for example, a pad provided on the device C.

[0072] Figure 7 This is a magnified view of the area surrounding device C.

[0073] When the control unit CONT causes the microscope 60 to measure the X and Y coordinates of a specific location F, such as... Figure 7 As shown, the position of the intersection of the first groove S1 and the second groove S2 near the outer peripheral surface of the workpiece W is determined, and a specific part F of the device C near the outer peripheral surface of the workpiece W is measured with reference to the intersection.

[0074] Next, the control unit CONT converts the X and Y coordinates of all measured specific parts F into a position in the θ direction and a distance (radius) from the axis H, using a predetermined position in the θ direction as a reference. The predetermined position in the θ direction is, for example, the position of the cutting tool 54 used for trimming. In other words, the control unit CONT converts the position of the measured specific parts F from the XY coordinate system to the rθ coordinate system.

[0075] After determining the position of a specific part F in the rθ coordinate system, the control unit CONT moves the displacement sensor 70 to the position of the cutting tool 54 to be trimmed. After the displacement sensor 70 has moved, the control unit CONT rotates the workpiece W by driving the rotary table 40, and simultaneously illuminates the specific part F of the device C with a measuring light 71 from the displacement sensor 70 to obtain the Z-direction position of the specific part F. While illuminating the specific part F with the measuring light 71, the control unit CONT moves the displacement sensor 70 along the Y-direction according to the distance between the specific part F and the axis H corresponding to the θ-direction position of the workpiece W. Thus, the Z-direction position of the specific part F in the device C can be measured intermittently and simply as the workpiece W rotates.

[0076] Based on the Z-direction position of a specific location F measured, the control unit CONT determines that device C with a large error is invalid and does not include the measured value of the invalid device C in the workpiece position information, and sets the device C (the specified device) as valid. The control unit CONT uses the measured value of the valid device C to intermittently acquire the error information of the rotational component of the workpiece W throughout the entire revolution. Figure 3 The image shows a specific part F in device C that is determined to be valid.

[0077] The control unit CONT acquires workpiece position information throughout the entire circumference. This workpiece position information is obtained by correlating the Z-direction position of a specific part F, which is intermittently measured by the displacement sensor 70, with the θ-direction position at which the Z-direction position is measured. In other words, based on the measurement results of the displacement sensor 70, the control unit CONT acquires workpiece position information throughout the entire circumference as error information for the rotational component of the workpiece W. This workpiece position information pertains to the Z-direction position of the specific part F at the θ-direction position.

[0078] [Edge trimming of the stepped section Wb]

[0079] The control unit CONT sets a finishing depth D (e.g., 150 μm) to form a stepped portion Wb. The control unit CONT uses at least one of the table position information and workpiece position information to form the stepped portion Wb at depth D. Based on the Z-direction position (displacement) of at least one of the holding surface 42a of the chuck table 42 and a specific portion F of the workpiece W at a position in the θ direction, the control unit CONT moves the insert 54 along the Z direction, cutting the workpiece W at a Z-direction position that cancels out the Z-direction displacement of at least one of the holding surface 42a and the specific portion F, thereby forming the stepped portion Wb.

[0080] The control unit CONT can perform trimming based on the residual cutting height or the cutting depth.

[0081] [Trimming based on residual cutting height]

[0082] Figure 8 The graphs are shown as curves G1 and G2. Curve G1 shows the Z-direction measurement position (height) h of the holding surface 42a of the chuck table 42 at the θ-direction position; curve G2 shows the cutting height h of the blade 54 at the θ-direction position when the workpiece W is trimmed by the blade 54 to a depth D1.

[0083] like Figure 8 As shown, when the workpiece W is rotated, the control unit CONT follows the displacement of the Z-direction height of the holding surface 42a of the chuck table 42 as shown in the curve G1 (obtained from the table position information) at the θ-direction position, and moves the blade 54 to the cutting height shown in the curve G2 to cut the workpiece W and form a step portion Wb. This can compensate for the error of the rotation component of the chuck table 42 and keep the residual cutting height f from the holding surface 42a to the step portion Wb constant.

[0084] [Trimming process based on depth of cut]

[0085] Figure 9 The graphs are G3 and G2. G3 shows the Z-direction measurement position (height) h of a specific part F of workpiece W at the θ-direction position. G2 shows the cutting height h of the blade 54 at the θ-direction position when the workpiece W is trimmed by the blade 54 at a depth D1.

[0086] like Figure 9As shown, when the workpiece W is rotated, the control unit CONT follows the displacement of the Z-direction height of a specific part F of the workpiece W at the θ-direction position obtained from the workpiece position information, and moves the insert 54 to the cutting height shown in the curve G2 to cut the workpiece W to form a step part Wb. This can compensate for the error of the rotation component of the specific part F in the workpiece W, and keep the cutting depth g from the specific part F to the step part Wb constant. Thus, the cutting depth from the surface Wa to the step part Wb is kept constant, resulting in a finishing depth D.

[0087] Since the Z-direction position obtained by measuring a specific part F is intermittent in the θ direction, the intermittently obtained Z-direction position is interpolated to generate workpiece position information, and the blade 54 is moved to the cutting height obtained by using the generated workpiece position information to perform trimming.

[0088] In addition to using the residual cutting height or the cutting depth as a reference, the table position information and the workpiece position information can be used to offset the errors of the rotational component of the chuck table 42 and the rotational component of the workpiece W.

[0089] Specifically, the control unit CONT calculates the difference between the error of the rotational component of the chuck table 42 at the θ-direction position and the error of the rotational component of the workpiece W. Then, the control unit CONT moves the blade 54 by a descending length to cut the workpiece W and form a stepped portion Wb, wherein the descending length is the length that follows the difference between the errors at the obtained θ-direction position.

[0090] This can offset both the error of the rotation component of the suction cup stage 42 and the error of the rotation component of the workpiece W.

[0091] As explained above, in the dicing device 10 of this embodiment, based on the measurement results of the displacement sensor 70, the worktable position information and the workpiece position information are acquired. The worktable position information is about the Z-direction position of the holding surface 42a in the θ direction, and the workpiece position information is about the Z-direction position of a specific part F of the workpiece W in the θ direction. Based on the acquired worktable position information and workpiece position information, the workpiece W is cut to form a stepped part Wb. Therefore, high-precision trimming processing can be performed, which corrects for the errors of the rotational components of the suction cup worktable 42 and the workpiece W.

[0092] Furthermore, in the dicing apparatus 10 of this embodiment, since the workpiece position information of a specific part F of the device C in the workpiece W is measured, high-precision trimming can be performed even if there are foreign objects such as residues or metal residues from the formation of the device on the surface of the workpiece W, without being affected by the presence of foreign objects. Moreover, compared with the case of measuring the entire circumference of the surface Wa of the workpiece W, the amount of data can be reduced.

[0093] [Second Implementation Method of Trimming Process]

[0094] Next, a second embodiment of the trimming process in which the stepped portion Wb is formed to a finishing depth D by cutting with the blade 54 will be described.

[0095] In the first embodiment of the above-described trimming process, the step portion Wb is formed to a finishing depth D by a single cut of the insert 54. In the second embodiment, the step portion Wb is formed with high precision by two cuts of the insert 54, including the cutting height, radial position, and eccentricity.

[0096] Specifically, in the second embodiment, the control unit CONT, based on the acquired workpiece position information, sets the cutting amount to be less than the amount required to achieve the finishing dimension during the first cut to form the step portion Wb. Then, it acquires the step portion position information and radial position information, which serve as Z-direction error information for the step portion Wb. Based on the acquired step portion position information, the control unit CONT corrects the error using the step portion position information and radial position information during the second cut and performs another cut.

[0097] The following is a description of each step.

[0098] [First trimming of the stepped section Wb]

[0099] In the second embodiment, the control unit CONT forms the stepped portion Wb at a depth D1 (e.g., 140 μm) shallower than the finishing depth D (e.g., 150 μm) through a first trimming process based on the workpiece position information. The difference between the finishing depth D and the depth D1 is preferably set to a value greater than the expected error amount, for example, based on the workpiece position information.

[0100] The first trimming of the stepped section Wb can be performed by selecting the above-mentioned references: the residual cutting height, the cutting depth, and both the table position information and the workpiece position information.

[0101] [Regarding cutting height]

[0102] Here, we will explain the two trimming processes based on the cutting depth.

[0103] [Acquisition of Step Location Information]

[0104] Figure 10 These are graphs G3 and G21. Graph G3 shows the relationship between the position in the θ direction and the measured position (height) h in the Z direction of a specific part F of the workpiece W. Graph G21 shows the relationship between the cutting height h of the insert 54 at the position in the θ direction when the workpiece W is trimmed by the insert 54 with a cutting depth (cutting amount) g during the first trimming process.

[0105] like Figure 10 As shown, when the control unit CONT forms the stepped portion Wb during the first trimming process, as described above, it acquires the Z-direction measurement position h = f(θ) of a specific part F of the workpiece W at the θ-direction position throughout the entire circumference as workpiece position information. Then, the control unit CONT performs cutting with a cutting height of h = f(θ) - g to form the stepped portion Wb.

[0106] After the step portion Wb is formed in the first trimming process, the control unit CONT acquires the step portion position information, which is the error information of the rotation component of the step portion Wb.

[0107] Figure 11 This is a diagram illustrating the steps for obtaining the position information of the step section. Figure 11 The diagram of device C is omitted.

[0108] like Figure 11 As shown, the control unit CONT causes the measuring light 71 to illuminate the stepped portion Wb of the workpiece W held by the chuck stage 42, and at the same time, the chuck stage 42 and the workpiece W are rotated in the θ direction by rotating the stage 40.

[0109] The control unit CONT acquires the step position information throughout the entire circumference. This step position information is obtained by correlating the Z-direction position of the step Wb measured by the displacement sensor 70 with the θ-direction position measured at that Z-direction position. That is, based on the measurement results of the displacement sensor 70, the control unit CONT uses the step position information of the Z-direction position of the step Wb at the θ-direction position as the error information of the rotation component of the step Wb, and acquires h = g(θ) throughout the entire circumference.

[0110] Here, if the machining error in the Z direction at the θ direction position during the first trimming is set as e(θ), then e(θ) can be obtained by the following formula (1).

[0111] e(θ)=g(θ)-f(θ)+g…(1)

[0112] For the cutting height h during the second trimming process shown in curve G21, the machining error e(θ) obtained by the second cutting depth g2 and equation (1) is expressed by equation (2).

[0113] h=f(θ)-g-g2-e(θ)…(2)

[0114] Then, from equations (1) and (2), we obtain equation (3).

[0115] h=2×f(θ)-g(θ)-2×g-g2…(3)

[0116] During the second trimming process, the control unit CONT causes the cutting tool to cut at the cutting height obtained from equation (3) to form the stepped portion Wb. As a result, the machining error from the first trimming process can be eliminated.

[0117] Furthermore, the machining error e(θ) is not generated during measurement, but rather by the deflection of the cutting tool 54, the deflection of the chuck table 42, and the deformation of the workpiece W caused only by the machining load during machining. Therefore, the more equal the loads during the first and second trimming processes, the more precise the deep machining can be achieved.

[0118] Furthermore, in trimming based on the residual cutting height, similar to the trimming based on the cutting depth mentioned above, high-precision deep machining can be achieved through two trimming processes.

[0119] [Regarding radial position]

[0120] Before the control unit CONT performs another cut on the stepped portion Wb using the insert 54, it is associated with the stepped portion Wb formed during the first trimming process, such as... Figure 12 As shown, the eccentricity and eccentricity direction between the first center C1 of the outer diameter R2 of the workpiece W and the second center C2 of the inner diameter R1 of the stepped part Wb are obtained.

[0121] Specifically, the control unit CONT controls the positions of the X-carrier 32 and the Y-carrier 46B to cause the measuring light 71 of the displacement sensor 70 to scan along a plane (XY plane) parallel to the X and Y directions. More specifically, the control unit CONT causes the measuring light 71 to scan radially along a first center C1 centered on the outer diameter of the workpiece W, thereby causing the measuring light 71 to traverse the step portion Wb between the inner region Wc and the outer side of the workpiece W.

[0122] When the measuring light 71 crosses the step portion Wb, the displacement sensor 70 continuously outputs the Z-direction positions of the workpiece W surface Wa, the step portion Wb, and the outer side of the workpiece W (suction cup stage 42) to the control unit CONT after corresponding the measured Z-direction positions with the positions on the XY plane.

[0123] The control unit CONT is based on the measured value of the Z-direction position output by the displacement sensor 70 and the measured position on the XY plane of each Z-direction position, such as... Figure 4 As shown, the calculation yields: the X-direction and Y-direction positions of the first edge portion E1 at the boundary between the surface Wa of workpiece W and the step portion Wb, where the Z-direction measurement value changes when the measuring light 71 crosses the step portion Wb; and the X-direction and Y-direction positions of the second edge portion E2 located in the outer shape portion Wd of workpiece W.

[0124] Furthermore, when a measurement result showing an upwardly protruding portion is obtained in the step portion Wb between the first edge portion E1 and the second edge portion E2, for example, the uneven wear of the blade 54 can be detected.

[0125] like Figure 12 As shown, the control unit CONT performs position measurements of the first edge portion E1 and the second edge portion E2 at three or more locations that are different from each other in the circumferential direction centered on the first center C1. In this embodiment, the measurements are performed at three locations θ1, θ2, and θ3 that are different from each other in the circumferential direction. The first edge portion E1 at locations θ1, θ2, and θ3 is designated as first edge portion E11, first edge portion E12, and first edge portion E13, respectively. The second edge portion E2 at locations θ1, θ2, and θ3 is designated as second edge portion E21, second edge portion E22, and second edge portion E23, respectively.

[0126] The control unit CONT can calculate and obtain the outer diameter of the workpiece W and the position of the first center C1 based on the coordinates of the second edge portions E21, E22, and E23 in the XY plane. The control unit CONT can also calculate and obtain the outer diameter R1 of the inner region Wc (the inner diameter of the stepped portion Wb) and the position of the second center C2 based on the coordinates of the first edge portions E11, E12, and E13 in the XY plane. From the obtained positions of the first center C1 and the second center C2, the control unit CONT can obtain the eccentricity and eccentricity direction of the inner region Wc relative to the workpiece W. Based on the eccentricity of the inner region Wc relative to the workpiece W, the control unit CONT can obtain the position offset of the cutting tool 54.

[0127] Then, in the second trimming process, the control unit CONT adjusts the position of the X carriage 32 and the Y carriage 46A to correct the eccentricity and eccentricity direction of the inner region Wc. At the same time, the trimming width L is set to make the outer diameter of the inner region Wc a specified outer diameter value, and the workpiece W is cut again, thereby forming an inner region Wc with a specified outer diameter (inner diameter of the step part Wb) R1 whose eccentricity is corrected.

[0128] As explained above, in the dicing device 10 of this embodiment, in addition to achieving the same effect as the first embodiment described above, the blade 54 cuts the stepped portion Wb recessed in the Z direction at a depth g shallower than the predetermined depth D on the outer periphery of the workpiece W based on the acquired workpiece position information. Then, based on the measurement results of the displacement sensor 70, the step portion position information of the Z direction position of the step portion Wb at the θ direction position is acquired, and the blade 54 cuts the step portion Wb again by the cutting amount g2 of the difference between the acquired step portion position information and the predetermined depth D. Therefore, higher precision trimming can be achieved.

[0129] Furthermore, in the dicing device 10 of this embodiment, after forming a stepped portion Wb with an inner diameter whose diameter is larger than a predetermined diameter in the first trimming process, in the second trimming process, the eccentricity and eccentricity direction between the first center C1 of the outer diameter R2 of the workpiece W and the second center C2 of the inner diameter R1 of the stepped portion Wb are corrected by the blade 54, and the workpiece W is cut again, thereby enabling the formation of an inner region Wc with a predetermined diameter whose eccentricity is corrected with high precision.

[0130] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, it is self-evident that the present invention is not limited to these examples. The various shapes and combinations of the structural components shown in the above examples are merely illustrative, and various modifications can be made according to design requirements without departing from the spirit of the present invention.

[0131] For example, in the above embodiments, a structure in which the stepped portion Wb is formed by one or two trimming processes is illustrated, but the structure is not limited to this. A structure in which the stepped portion Wb is formed by three or more trimming processes may also be used.

[0132] Furthermore, in the above embodiment, a specific part F in the device C is illustrated as a pad structure, but it is not limited to this structure. Any part in the device C that is easy to determine and can be measured by the displacement sensor 70 can also be any other part.

[0133] Furthermore, in the above embodiments, a structure for forming the step portion Wb based on the worktable position information and the workpiece position information is illustrated, but it is not limited to this structure. It is also possible to form the step portion Wb based on the workpiece position information without using the worktable position information.

[0134] Explanation of reference numerals in the attached figures

[0135] 10…Scissors device

[0136] 40… Rotary worktable

[0137] 42… Suction Cup Worktable

[0138] 46A…Y carriage (first drive unit)

[0139] 46B…Y carriage (second drive unit)

[0140] 51A, 51B... Cutting section

[0141] 52…spindle

[0142] 53… Rotation axis

[0143] 54…blade

[0144] 60…microscope

[0145] 70… Displacement sensor

[0146] 71…Measuring light

[0147] C…devices

[0148] CONT…Control Department

[0149] H…axis

[0150] S1…First trench section

[0151] S2…Second Groove Section

[0152] W…workpiece

[0153] Wb…steps

[0154] Wc…inner area

[0155] Wd…Exterior Design

Claims

1. A dicing device, comprising: A suction cup worktable that holds the workpiece in a holding surface and can move along the X direction; A rotary table for rotating the suction cup worktable about the Z-axis; A microscope that can move along the Y direction and can observe the workpiece; A displacement sensor capable of moving along the Y direction and used to measure the position of the workpiece in the normal direction; The cutting section includes a cutting blade for cutting the workpiece held by the chuck table and a spindle for rotating the cutting blade about a rotation axis orthogonal to the normal direction; and The control unit is configured to control the movement of the suction cup stage, the rotary stage, the microscope, and the displacement sensor based on the measurement results of the microscope and the displacement sensor. The workpiece has a plurality of devices arranged in a region of the workpiece defined by a plurality of first grooves extending along the X direction and a plurality of second grooves extending along the Y direction. The control unit is configured to: For a specific location of the device on the workpiece, located radially outward about the Z-axis, based on the measurement results of the displacement sensor, workpiece position information is acquired throughout the entire circumference. This workpiece position information pertains to the position of the normal direction at the circumferential position centered on the Z-axis. Based on the acquired workpiece position information, the blade cuts a stepped portion recessed along the Z direction on the outer periphery of the workpiece.

2. The dicing device according to claim 1, wherein, The control unit is configured to: based on the acquired workpiece position information, acquire the cutting amount at the circumferential position, and while rotating the workpiece, move the blade along the normal direction and cut the stepped portion according to the circumferential position of the blade and the acquired cutting amount.

3. The dicing device according to claim 2, wherein, The control unit is configured to: Based on the acquired workpiece position information, after the cutting blade cuts the step portion to a depth shallower than a specified depth, the step portion position information is acquired throughout the entire circumference based on the measurement results of the displacement sensor. This step portion position information pertains to the position of the step portion in the normal direction at its circumferential position. The cutting amount is based on the difference between the step position information and the specified depth, causing the cutting tool to cut the step again.

4. The dicing device according to claim 2, wherein, The control unit is configured to: obtain the cutting amount at the circumferential position based on the worktable position information and the workpiece position information, wherein the worktable position information is information about the position of the holding surface in the normal direction at the circumferential position.

5. The dicing device according to claim 3, wherein, The control unit is configured to: based on the worktable position information and the workpiece position information, cause the cutting blade to cut the stepped portion to a depth shallower than the predetermined depth, wherein the worktable position information is information about the position of the holding surface in the normal direction at the circumferential position.

6. The dicing device according to claim 5, wherein, The control unit is configured to: before the blade cuts the step portion again, based on the measurement results of the displacement sensor, obtain the eccentricity and eccentricity direction between the first center of the outer diameter of the workpiece and the second center of the inner diameter of the step portion, and based on the eccentricity and eccentricity direction, cut the step portion again to the position after the second center has been corrected.

7. The dicing device according to claim 6, wherein, The control unit is configured to form the stepped portion with an inner diameter larger than a predetermined diameter when the blade cuts the stepped portion recessed along the Z direction on the outer periphery of the workpiece at a depth shallower than the predetermined depth.

8. The dicing apparatus according to any one of claims 1, 4, 5, 6, and 7, wherein, The control unit is configured to convert the coordinates of the X-direction and Y-direction of the specific part into the circumferential position and the distance from the Z-axis, and to move the displacement sensor along the Y-direction according to the circumferential position of the specific part and measure the position of the normal direction.

9. The dicing apparatus according to any one of claims 1, 4, 5, 6, and 7, wherein, The specific location is the pad located on the device.

10. The dicing apparatus according to any one of claims 1, 4, 5, 6, and 7, wherein, The control unit is configured to set the specified devices included in the workpiece position information according to the measurement results of the displacement sensor on the position of all the devices in the normal direction.

11. The dicing apparatus according to any one of claims 5 to 7, wherein, Let the workpiece position information be f(θ). Let the position information of the step be g(θ). The cutting depth at the circumferential position that is shallower than the specified depth is defined as g. The cutting amount based on the difference between the step location information and the specified depth is set as g2. When the cutting height of the cutting tool in the normal direction during the second cutting is set to h, The following relationship must be satisfied: h=2×f(θ)-g(θ)-2×g-g2.

12. A trimming method for a dicing apparatus, the dicing apparatus comprising: a suction cup stage that holds a workpiece with a holding surface and is movable in the X direction; a rotary stage for rotating the suction cup stage about a Z-axis; a microscope movable in the Y direction and capable of observing the workpiece; a displacement sensor movable in the Y direction and for measuring the position of the workpiece in the normal direction; a cutting unit including a cutting blade for cutting the workpiece held by the suction cup stage and a spindle for rotating the cutting blade about a rotation axis orthogonal to the normal direction; and a control unit configured to control the movement of the suction cup stage, the rotary stage, the microscope, and the displacement sensor based on measurement results from the microscope and the displacement sensor. The trimming method includes: Prepare the workpiece having multiple devices, the multiple devices being arranged in an area of ​​the workpiece divided by a plurality of first groove portions extending along the X direction and a plurality of second groove portions extending along the Y direction; For a specific part of the device of the workpiece located on the outer side of the device in the radial direction centered on the Z-axis, the workpiece position information is acquired throughout the entire circumference based on the measurement results of the displacement sensor. The workpiece position information is information about the position of the workpiece in the normal direction at the circumferential position centered on the Z-axis. as well as Based on the acquired workpiece position information, the blade cuts a stepped portion recessed along the Z direction on the outer periphery of the workpiece.

Images