Wafer processing system and wafer processing method

Abstract

The present application provides a wafer processing system and a wafer processing method for improving the accuracy of a closed interval of laser processing. The wafer processing system (20) is configured to perform first laser processing of forming a laser processing trace in a first cutting lane and second laser processing of forming a laser processing trace in a second cutting lane with a cross section intersecting the first cutting lane being set as a closed interval. The wafer processing system (20) comprises a coaxial AF device (24) capable of detecting the edge position of a wafer (10), a relative movement mechanism (23) capable of moving the wafer relative to the coaxial AF device, and a control device (30) for controlling each element of the wafer processing system. The control device acquires a pre-processing size of the second cutting lane before the first laser processing, acquires a post-processing size of the second cutting lane based on the edge position of the wafer after the first laser processing, and corrects the closed interval based on the expansion amount calculated from the post-processing size and the pre-processing size.

Description

Technical Field

[0001] This disclosure relates to a wafer processing system and a wafer processing method. Background Technology

[0002] A wafer incorporating various components such as semiconductor devices and electronic parts is divided into individual chips by being cut along a first dicing line extending in a first direction and a second dicing line extending in a second direction orthogonal to the first direction. As a method for dividing wafers, a laser processing method, such as that in Patent Document 1, is known. In the method of Patent Document 1, after irradiating the wafer with a laser in the order of the first and second dicing lines to form fragile laser processing marks inside the wafer, the wafer is divided by applying an external force along each dicing line.

[0003] In such laser processing of wafers, thermal damage associated with laser processing is prone to occur outside the cutting track at the intersection of the first and second cutting tracks. Therefore, in the subsequent laser processing of the second cutting track, the intersection with the first cutting track is designated as an "off" zone for laser irradiation. Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2010-123797 Summary of the Invention The problem that the invention aims to solve

[0005] However, it is known that wafers expand in a second direction, orthogonal to the first dicing, due to laser processing along the first dicing. Patent Document 1 discloses a method for measuring the amount of wafer expansion in the second direction using a camera mechanism and correcting the laser irradiation position based on the measurement result, but there is still room for improvement in correcting the aforementioned closed range. Solution for solving the problem

[0006] A wafer processing system for solving the above-mentioned problems is configured to perform: a first laser processing, in which laser light is irradiated from a laser irradiation unit along a plurality of first dicing paths to form laser processing marks inside the wafer; and a second laser processing, after the first laser processing, in which laser light is irradiated from the laser irradiation unit along a plurality of second dicing paths extending intersecting the plurality of first dicing paths, with the intersections of the intersections with the first dicing paths designated as closed intervals of the laser light, to form laser processing marks inside the wafer. The wafer processing system includes: a detection unit capable of detecting the edge position of the wafer; a relative movement unit capable of relative movement between the wafer and the detection unit; and a control unit for controlling various elements of the wafer processing system. The control unit is configured to: acquire pre-processing dimensions for the plurality of second dicing paths before the first laser processing; control the relative movement unit and the detection unit in such a manner that the post-processing dimensions of the second dicing paths are acquired based on the edge position of the wafer after the first laser processing; calculate the expansion amount of each of the plurality of second dicing paths based on the post-processing dimensions and the pre-processing dimensions; and correct the closed intervals for each of the plurality of second dicing paths based on the expansion amounts.

[0007] A wafer processing method for solving the above-mentioned problems includes: a first laser processing method, in which laser light is irradiated from a laser irradiation unit along a plurality of first dicing paths to form laser processing marks inside the wafer; and a second laser processing method, in which, after the first laser processing, laser light is irradiated from the laser irradiation unit along a plurality of second dicing paths extending intersecting the plurality of first dicing paths, with the intersections of the intersections with the first dicing paths being closed sections of the laser light, to form laser processing marks inside the wafer. In the wafer processing method, a wafer processing system capable of performing the first laser processing and the second laser processing includes: a detection unit capable of detecting the edge position of the wafer; a relative movement unit capable of moving the wafer relative to the detection unit; and a control unit capable of controlling the various elements of the wafer processing system. The control unit performs the following operations: controlling the relative movement unit and the detection unit in a manner that the pre-processing dimensions of the plurality of second cutting channels are obtained based on the edge position of the wafer before the first laser processing; controlling the relative movement unit and the detection unit in a manner that the post-processing dimensions of the plurality of second cutting channels are obtained based on the edge position of the wafer after the first laser processing; calculating the expansion amount of each of the plurality of second cutting channels based on the post-processing dimensions and the pre-processing dimensions; and correcting the closing interval for each of the plurality of second cutting channels based on the expansion amount. Invention Effects

[0008] According to this disclosure, the accuracy of the shut-off zone for turning off laser irradiation can be improved. Attached Figure Description

[0009] Figure 1 This is a top view showing a simplified structure of an example of a wafer processed by a wafer processing system in the first embodiment. Figure 2 This is a schematic diagram illustrating a simplified structure of the wafer processing system in the first embodiment. Figure 3 This is a block diagram showing a simplified structure of the information processing device constituting the control device in the first embodiment. Figure 4 This is a functional block diagram illustrating a simplified structure of the control device in the first embodiment. Figure 5 (a) is a schematic diagram showing the formation location of laser processing marks in the first embodiment without correction of the closed region. Figure 5 (b) is a diagram schematically showing the location of laser processing marks formed when the closed interval has been corrected in the first embodiment. Figure 6 This is a diagram schematically illustrating an example of a method for obtaining pre-processing dimensions in the first embodiment. Figure 7 This is a diagram schematically illustrating an example of a method for obtaining pre-processing dimensions in the first embodiment. Figure 8 This is a diagram schematically illustrating an example of a method for obtaining pre-processing dimensions in the first embodiment. Figure 9 This is a diagram showing a simplified structure of the wafer processing system in the second embodiment. Figure 10 This diagram schematically illustrates the scenario in the second embodiment where the edge is detected by the front AF device. Figure 11 This is a diagram showing a simplified structure of the wafer processing system in the third embodiment. Figure 12 This diagram schematically illustrates the situation in the third embodiment where laser processing is performed on the workpiece while the edge of the next workpiece is detected using a lateral AF device. Figure 13 This is an explanatory diagram used to illustrate the phenomenon that occurs in the fourth embodiment when lower and upper processing marks are formed without setting a closed interval. Figure 14 This diagram schematically illustrates the situation where a closed section is set up in the fourth embodiment, resulting in upper-layer processing marks. Detailed Implementation

[0010] (First Implementation) Reference Figures 1 to 8 A first embodiment of the wafer processing system and wafer processing method will be described.

[0011] like Figure 1 As shown, the wafer 10 is divided into individual chips by being cut by a first dicing 11 extending along a first direction D1 and a second dicing 12 extending along a second direction D2. The intersection 13 is the portion where the first dicing 11 and the second dicing 12 intersect.

[0012] (Wafer processing system) like Figure 2 As shown, the wafer 10 is laser-processed using the wafer processing system 20. The wafer processing system 20 includes a worktable 21, a laser irradiation unit 22, a relative movement mechanism 23, a coaxial AF device 24, a camera 25, and a control device 30.

[0013] In the wafer processing system 20, one direction in the horizontal direction is called the X direction, and the direction orthogonal to the X direction in the horizontal direction is called the Y direction. The X direction is the direction in which the cutting path, which is the object to be processed in each process, extends. The vertical direction orthogonal to the XY direction is called the Z direction. Regarding the X direction, depending on the situation, the direction indicated by the arrow in the diagram is called the +X direction, and the opposite direction of the +X direction is called the -X direction. Regarding the Y direction, depending on the situation, the direction indicated by the arrow in the diagram is called the +Y direction, and the opposite direction of the +Y direction is called the -Y direction.

[0014] The worktable 21 supports the wafer 10 via the cutting tape 16. The cutting tape 16 supports the device surfaces of the wafer 10 where various devices such as semiconductor devices and electronic components are formed. The worktable 21 is configured to move along the X direction and rotate about the Z direction as a rotation axis via a relative movement mechanism 23 that functions as a relative movement part. The movement speed of the worktable 21 in the X direction is called the laser processing speed.

[0015] The laser irradiation unit 22 irradiates the wafer 10 supported by the worktable 21 with laser L1. The laser irradiation unit 22 is configured to move along the Y and Z directions via a relative movement mechanism 23. The laser irradiation unit 22 is configured to temporarily interrupt the irradiation of the wafer 10 with laser L1 by means of on / off control or the like.

[0016] The laser irradiation unit 22 includes a laser emission unit 26, a condenser lens 27, and a dichroic mirror 28. The laser emission unit 26 and the condenser lens 27 are configured to move relative to each other in the Z direction via a moving mechanism (not shown). The dichroic mirror 28 is disposed between the laser emission unit 26 and the condenser lens 27 in the Z direction.

[0017] The laser emitting section 26 emits a laser L1 of a predetermined wavelength toward the focusing lens 27. The laser L1 is a pulsed laser. After passing through the dichroic mirror 28, the laser L1 reaches the focusing lens 27. The focusing lens 27 focuses the laser L1 onto a focal point P. The focal point P is the irradiation position of the laser L1. Inside the wafer 10 irradiated by the laser L1, a laser processing mark 15 is formed near the focal point P. The laser processing mark 15 is a more brittle area than the unprocessed portion, becoming the starting point of cracking. Furthermore, it is preferable that the laser irradiation section 22 uses an optical element capable of high-speed processing of the ON / OFF state of the laser L1, such as an acousto-optic modulator.

[0018] The irradiation position of laser L1 in the XY direction is adjusted by the relative movement of the worktable 21 and the laser irradiation unit 22. In addition, the irradiation position of laser L1 in the Z direction is adjusted by the movement of the laser irradiation unit 22 in the Z direction or by the relative movement of the laser emission unit 26 in the Z direction and the focusing lens 27.

[0019] A coaxial AF device 24 is mounted on the laser irradiation unit 22. The coaxial AF device 24 functions as a detection unit capable of detecting the edge position of the wafer 10. The coaxial AF device 24 detects the height position H of the surface of the wafer 10. The coaxial AF device 24 emits AF light L2 toward the dichroic mirror 28. The AF light L2 is, for example, a detection laser with a specified wavelength. The dichroic mirror 28 reflects the AF light L2 emitted by the coaxial AF device 24 toward the condenser lens 27. The coaxial AF device 24 emits the AF light L2 in such a way that the optical axis of the AF light L2 reflected by the dichroic mirror 28 is coaxial with the optical axis of the laser L1. The condenser lens 27 focuses the AF light L2 reflected by the dichroic mirror 28 onto the surface of the wafer 10. The reflected light, after being refracted by the condenser lens 27, is reflected again toward the coaxial AF device 24 by the dichroic mirror 28. The coaxial AF device 24 detects the height position H of the surface of the wafer 10 based on the reflected light of the AF light L2 reflected from the surface of the wafer 10.

[0020] Camera 25 is mounted on laser illumination unit 22. Camera 25 captures images of alignment marks set on chip 10. Camera 25 outputs image data representing the captured image to control device 30.

[0021] (Control device) The control device 30 is a control unit that comprehensively controls the operation of the wafer processing system 20. The control device 30 controls the laser irradiation unit 22, the relative movement mechanism 23, the coaxial AF device 24, and the camera 25.

[0022] like Figure 3 As shown, the control device 30 is configured 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. However, this hardware configuration is just one example; it can also be implemented using other hardware.

[0023] The communication device H11 is an interface for establishing communication paths with other devices to perform data transmission and reception, such as a network interface card or a wireless interface.

[0024] Input device H12 is a device that accepts various types of information input. Examples of input devices H12 include touch panels, mice, and keyboards. Output device H13 is a display, speaker, etc. that displays various information.

[0025] Storage device H14 stores data and programs used to perform various functions of control device 30. Examples of storage devices H14 include ROM, RAM, hard disk, and SSD.

[0026] Processor H15 uses programs and data stored in storage device H14 to control various processes. Examples of processor H15 include CPUs and MPUs. Processor H15 expands programs stored in ROM or the like into RAM to execute various commands corresponding to different processes. For example, when the application program of control device 30 is started, processor H15 executes commands corresponding to the processes described later.

[0027] Processor H15 is not limited to a processor that performs software processing for all the processes it executes. For example, processor H15 may also have dedicated hardware circuitry (e.g., application-specific integrated circuit: ASIC) that performs hardware processing for at least a portion 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 circuitry that executes at least a portion of the various processes, or (3) a combination thereof. Processors include a CPU and memories such as RAM and ROM, which store program code or instructions configured to cause the CPU to execute processes. Memory, i.e., non-transitory computer-readable media, includes all available media that can be accessed by a general-purpose or special-purpose computer.

[0028] The processing conditions 31 of laser L1 and wafer information 32 are input to the control device 30 via the communication device H11 and the input device H12. The processing conditions 31 are configured to include the output of laser L1, the repetition frequency of laser L1, the position of the laser processing mark 15 in the Z direction (i.e., the laser processing position), the laser processing speed, and the range of the closed interval described later.

[0029] The wafer information 32 is information related to the shape of the wafer 10. Specifically, the wafer information 32 is configured to include the external shape of the wafer 10, the position of each first dicing 11 relative to the alignment marks provided on the wafer 10, the position of each second dicing 12, and the position of each intersection 13. In addition, the wafer information 32 is configured to include the number of first dicing 11s, the number of second dicing 12s, and the number n of intersections n between each second dicing 12 and the first dicing 11.

[0030] like Figure 4 As shown, the control device 30 includes an alignment detection unit 36, a first processing control unit 37, a closed interval setting unit 38, a pre-processing dimension acquisition unit 39, a post-processing dimension acquisition unit 40, a closed interval correction unit 41, and a second processing control unit 42, which function as functional units that perform their functions through the execution of various programs.

[0031] The alignment detection unit 36 ​​detects the position of the wafer 10 relative to the stage 21. For example, the alignment detection unit 36 ​​controls the relative movement mechanism 23, thereby adjusting the position of the camera 25 relative to the alignment mark provided on the wafer 10. Next, the alignment detection unit 36 ​​acquires image data obtained by using the camera 25 to capture the alignment mark. Furthermore, the alignment detection unit 36 ​​performs image processing on the image data, thereby detecting the position of the alignment mark relative to the stage 21 as the wafer position.

[0032] The first processing control unit 37 performs first laser processing on the first cutting track 11 sequentially based on processing conditions 31, wafer information 32, and wafer position. During the first laser processing, the first processing control unit 37 controls the laser irradiation unit 22, the relative movement mechanism 23, and the coaxial AF device 24.

[0033] Specifically, after controlling the relative movement mechanism 23 to rotate the worktable 21 so that the first cutting track 11 is along the Y direction, the first processing control unit 37 sequentially performs the first laser processing starting from the first cutting track 11 located at the outermost end in the -Y direction.

[0034] In the first laser processing, the first processing control unit 37 controls the relative movement mechanism 23 to move the worktable 21 from the processing start position to the processing finish position. The processing start position is the position where the laser irradiation unit 22 is arranged on the +X direction side of the first cutting track 11, which is the object of processing. The processing finish position is the position where the laser irradiation unit 22 is arranged on the -X direction side of the first cutting track 11, which is the object of processing. During the movement of the worktable 21 from the processing start position to the processing finish position, the first processing control unit 37 controls the laser irradiation unit 22 based on the height position H detected by the coaxial AF device 24 to form a laser processing mark 15 at the laser processing position of the first cutting track 11. In addition, "during the first laser processing" refers to the period during which the worktable 21 is moved from the processing start position to the processing finish position in order to form a laser processing mark 15 on the first cutting track 11, which is the object of processing.

[0035] The shut-off interval setting unit 38 sets the shut-off interval for the laser L1 in each of the second dicing channels 12 based on the wafer information 32 and the wafer position. The shut-off interval is the interval in which the laser L1 is temporarily shut off from irradiation by not irradiating the intersection 13. Specifically, the shut-off interval setting unit 38 sets a predetermined range on both sides of the intersection 13 in the second direction D2 as the shut-off interval.

[0036] The pre-processing dimension acquisition unit 39 controls the relative movement mechanism 23 and the coaxial AF device 24 to acquire the dimensions of each of the second cutting paths 12 before the first laser processing, that is, before the expansion caused by the first laser processing, i.e., the pre-processing dimension Wa.

[0037] The dimension acquisition unit 40 controls the relative movement mechanism 23 and the coaxial AF device 24 to acquire the dimension of each second cutting track 12 after the first laser processing, that is, the dimension after processing Wb after the expansion caused by the first laser processing.

[0038] The closing interval correction unit 41 corrects the closing interval for each second cutting track 12 based on the pre-processing dimension Wa and the post-processing dimension Wb. Specifically, for each second cutting track 12, the closing interval correction unit 41 calculates the average expansion amount ΔWμ (=ΔW / n) obtained by dividing the difference between the post-processing dimension Wb and the pre-processing dimension Wa, i.e., the expansion amount ΔW (=Wb-Wa), by the number of intersections n with the first cutting track 11. Furthermore, the closing interval correction unit 41 sets each intersection 13 to be offset by the average expansion amount ΔWμ to correct the closing interval set by the closing interval setting unit 38.

[0039] Specifically, such as Figure 5 As shown in (a), the pre-correction shut-off interval did not take into account the expansion of the wafer 10 caused by the first laser processing. Therefore, if the second laser processing is performed without considering the expansion of the wafer 10, laser L1 will be irradiated onto the intersection 13. Therefore, as Figure 5 As shown in (b), the closing interval correction unit 41 corrects the closing interval by offsetting each intersection 13 with an average expansion amount ΔWμ.

[0040] The second processing control unit 42 performs second laser processing sequentially on the second cutting track 12 based on processing conditions 31, wafer information 32, wafer position, and the corrected closing interval. During the second laser processing, the second processing control unit 42 controls the laser irradiation unit 22, the relative movement mechanism 23, and the coaxial AF device 24.

[0041] Specifically, after controlling the relative movement mechanism 23 to rotate the worktable 21 so that the second cutting path 12 is along the Y direction, the second processing control unit 42 sequentially performs the second laser processing starting from the outermost second cutting path 12 located in the -Y direction. In the second laser processing, the second processing control unit 42 controls the relative movement mechanism 23 to move the worktable 21 from the processing start position to the processing completion position. The processing start position is the position where the laser irradiation unit 22 is positioned on the +X direction side of the second cutting path 12 that is the object of processing. The processing completion position is the position where the laser irradiation unit 22 is positioned on the -X direction side of the second cutting path 12 that is the object of processing. During the movement of the worktable 21 from the processing start position to the processing completion position, the second processing control unit 42 controls the laser irradiation unit 22 to form a laser processing mark 15 at the laser processing position of the second cutting path 12 that is the object of processing, based on the height position H detected by the coaxial AF device 24. In addition, "second laser processing time" refers to the period during which the worktable 21 is moved from the processing start position to the processing completion position in order to form a laser processing mark 15 on the second cutting path 12, which is the object of processing.

[0042] (Methods for obtaining various sizes) The following is for reference Figures 6-8 The methods for obtaining the pre-processing dimension Wa and the post-processing dimension Wb are explained in detail.

[0043] (Method 1 for obtaining dimensions before processing) In method 1 for obtaining the pre-processing dimension Wa, the wafer information 32 is configured to include the pre-processing dimension Wa of each of the second dicing tracks 12. The pre-processing dimension acquisition unit 39 acquires the pre-processing dimension Wa based on the wafer information 32.

[0044] (Method 2 for obtaining dimensions before processing) In the method 2 for obtaining the pre-processing dimension Wa, the pre-processing dimension obtaining unit 39 obtains the pre-processing dimension Wa of each second cutting track 12 based on the edge position of the first cutting track 11.

[0045] Specifically, such as Figure 6As shown, the pre-processing dimension acquisition unit 39 detects the height position H obtained by the coaxial AF device 24 during the first laser processing for each first cutting path 11. Figure 6 The edge position of the first dicing 11 is represented by solid dots. The pre-processing dimension acquisition unit 39 calculates an approximate curve representing the outer periphery of the wafer 10 based on the edge position of the first dicing 11. The pre-processing dimension acquisition unit 39 acquires the pre-processing dimension Wa of the second dicing 12 based on the edge position of the second dicing 12 detected according to the calculated approximate curve.

[0046] In addition, in the method of obtaining the pre-processing dimension Wa based on the edge position of the first cutting track 11, the pre-processing dimension acquisition unit 39 can also control the relative movement mechanism 23 and the coaxial AF device 24 by scanning each first cutting track 11 to detect the height position H of each first cutting track 11 before performing the first laser processing.

[0047] (Method 3 for obtaining dimensions before processing) In the method 3 for obtaining the pre-processing dimension, the pre-processing dimension obtaining unit 39 obtains the pre-processing dimension Wa of the second cutting track 12 based on the edge position of the second cutting track 12.

[0048] Specifically, such as Figure 7 As shown, before performing the first laser processing, the pre-processing dimension acquisition unit 39 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the height position H of each of the second cutting paths 12. Furthermore, the pre-processing dimension acquisition unit 39 detects the height position H detected by the coaxial AF device 24 based on the height position H detected by the coaxial AF device 24. Figure 7 The edge position of each second cutting track 12 is represented by a solid dot, and the pre-processing dimension Wa of each second cutting track 12 is obtained based on the detected edge position.

[0049] (Method 4 for obtaining dimensions before processing) In the method 4 for obtaining the pre-processing dimension Wa, the pre-processing dimension obtaining unit 39 obtains the pre-processing dimension Wa of all the second cutting tracks 12 based on the edge position of a portion of the second cutting track 12.

[0050] Specifically, such as Figure 8As shown, the pre-processing dimension acquisition unit 39 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the height position H of a portion of the second cutting sipe 12. For example, the pre-processing dimension acquisition unit 39 detects the edge position by taking the second cutting sipe 12c located at the center of the second direction D2, the second cutting sipe 12e located at the outermost end of the second direction D2, and the second cutting sipe 12m located between the second cutting sipe 12c and the second cutting sipe 12e in the second direction D2 as detection objects. The pre-processing dimension acquisition unit 39 is based on... Figure 8 The edge positions of the second dicing tracks 12c, 12e, and 12m, represented by solid points, are used to calculate an approximate curve 45 representing the outer periphery of the wafer 10. The pre-processing dimension acquisition unit 39 acquires the pre-processing dimensions Wa of all the second dicing tracks 12 based on the edge positions of the second dicing tracks 12 detected according to the calculated approximate curve 45.

[0051] (Method 1 for obtaining dimensions after processing) In the method 1 for obtaining the post-processing dimension, the post-processing dimension acquisition unit 40 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the edge positions of all the second cutting tracks 12 after the first laser processing and before the second laser processing. Furthermore, the post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb for all the second cutting tracks 12 based on the edge positions detected by the coaxial AF device 24.

[0052] (Method 2 for obtaining dimensions after processing) In the post-processing dimension acquisition method 2, the post-processing dimension acquisition unit 40 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the edge position of a portion of the second cutting path 12 after the first laser processing and before the second laser processing. Furthermore, the post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb of all the second cutting paths 12 based on the edge position of a portion of the second cutting path 12 detected by the coaxial AF device 24.

[0053] For example, 40 pairs of dimensions acquisition units after processing Figure 8The edge positions of the second dicing channels 12c, 12e, and 12m are detected, and the post-processing dimensions Wb of the second dicing channels 12c, 12e, and 12m are calculated based on the detected edge positions. Furthermore, the post-processing dimension acquisition unit 40 calculates an approximate curve representing the outer periphery of the wafer 10 based on the edge positions of the second dicing channels 12c, 12e, and 12m. The post-processing dimension acquisition unit 40 also acquires the post-processing dimensions Wb of other second dicing channels 12 based on the edge positions of other second dicing channels 12 detected according to the calculated approximate curves. In this structure, it is preferable to include the second dicing channel 12c, which has the largest expansion amount ΔW, and the second dicing channel 12e, which has the smallest expansion amount ΔW, in the detection targets. This improves the accuracy of the post-processing dimensions Wb calculated using approximate curves.

[0054] Furthermore, for example, the post-processing dimension acquisition unit 40 calculates the expansion rate A = (Wb / Wa) based on the pre-processing dimension Wa and the post-processing dimension Wb for the second cutting path 12 that becomes the inspection target. The post-processing dimension acquisition unit 40 multiplies the average expansion rate Aμ calculated based on the expansion rate A of the inspection target with the pre-processing dimension Wa as a multiplication factor, thereby calculating the post-processing dimension Wb of the second cutting path 12 other than the inspection target. In such a structure, there can be only one second cutting path 12 that becomes the inspection target. For example, by setting the second cutting path 12c with the largest expansion amount ΔW as the inspection target, the accuracy of the post-processing dimension Wb of each second cutting path 12 can be improved. In addition, for example, by setting the second cutting path 12e located at the outermost end in the -Y direction as the inspection target, the relative movement between the worktable 21 and the laser irradiation unit 22 is minimized, thus shortening the time required to acquire the post-processing dimension Wb.

[0055] Additionally, for example, the post-processing dimension acquisition unit 40 selects the second dicing track 12 as the object of inspection in a manner that divides the entire wafer 10 into multiple regions, for example... Figure 8 As shown in the second cutting paths 12c, 12e, and 12m, the post-processing dimension acquisition unit 40 calculates the expansion rate A for each of the second cutting paths 12 that are to be inspected. Assuming a proportional relationship exists between the expansion rates A of two adjacent inspection objects, the post-processing dimension acquisition unit 40 estimates the estimated expansion rate A1 of the second cutting path 12 located between the two adjacent inspection objects. The post-processing dimension acquisition unit 40 multiplies the estimated expansion rate A1 as a multiplication factor with the original dimension Wa, thereby calculating the post-processing dimension Wb of the second cutting path 12 located between the two adjacent inspection objects.

[0056] As a specific example, the post-processing dimension acquisition unit 40 selects... Figure 8The second cutting paths 12c, 12e, and 12m shown are used as the detection objects. The post-processing dimension acquisition unit 40 calculates the expansion rates Ac, Ae, and Am for the second cutting paths 12c, 12e, and 12m, respectively. Furthermore, the post-processing dimension acquisition unit 40 calculates the post-processing dimension Wb of the second cutting path 12 located between the second cutting paths 12m and 12e based on the estimated expansion rate A1 calculated from the expansion rate Am of the second cutting path 12m and the expansion rate Ae of the second cutting path 12e. In addition, the post-processing dimension acquisition unit 40 calculates the post-processing dimension Wb of the second cutting path 12 located between the second cutting paths 12c and 12m based on the estimated expansion rate A1 calculated from the expansion rate Ac of the second cutting path 12c and the expansion rate Am of the second cutting path 12m.

[0057] Here, in the method of obtaining the post-processed dimension Wb of all second diced tracks 12 based on the edge position of a portion of the second diced tracks 12, the more second diced tracks 12 there are, the more likely errors will occur in the post-processed dimension Wb of the second diced tracks 12 other than the detection target. Therefore, the post-processed dimension acquisition unit 40 is preferably configured such that the more second diced tracks 12 obtained based on the wafer information 32, the more second diced tracks 12 are selected as the detection target. In this case, the post-processed dimension acquisition unit 40 preferably selects the second diced tracks 12 in a manner that ensures the configuration of the detection target is unbiased, such as... Figure 8 As shown in the diagram, the second cutting tracks 12c, 12e, and 12m. By selecting the second cutting track 12 as the inspection target based on the number of second cutting tracks 12, the accuracy of the post-processing dimension Wb of each second cutting track 12 can be improved.

[0058] (Method 3 for obtaining dimensions after processing) In method 3 for obtaining the post-processing dimension, the post-processing dimension acquisition unit 40 controls the relative movement mechanism 23 and the coaxial AF device 24 to detect the edge position of a specific second cutting track 12 after the first laser processing and before the second laser processing. The post-processing dimension acquisition unit 40 calculates the expansion rate A of the second cutting track 12 that is the object of detection, based on the pre-processing dimension Wa and the post-processing dimension Wb. The post-processing dimension acquisition unit 40 sets the expansion rate A of the object of detection as a multiplication factor to calculate the post-processing dimension Wb of the second cutting track 12 other than the object of detection.

[0059] In this structure, by designating the second cutting path 12c with the largest expansion amount ΔW as a specific second cutting path 12, the accuracy of the post-processed dimension Wb of the other second cutting paths 12 can be improved. Furthermore, by designating the second cutting path 12e that minimizes the relative movement between the worktable 21 and the laser irradiation unit 22 as a specific second cutting path 12, the time required to obtain the post-processed dimension Wb of the other second cutting paths 12 can be shortened.

[0060] (Method 4 for obtaining dimensions after processing) In the method 4 for obtaining the post-processed dimension, the post-processed dimension obtaining unit 40 processes the post-processed dimension obtained by the above-described methods 1 to 3 as the first post-processed dimension Wb1.

[0061] The post-processing dimension acquisition unit 40 detects the edge position of the second cutting path 12, which is the object of processing, based on the height position H detected by the coaxial AF device 24 for the second cutting path 12 during the second laser processing. The post-processing dimension acquisition unit 40 acquires the post-processing dimension of the second cutting path 12, which is the object of processing, based on the edge position, as the second post-processing dimension Wb2.

[0062] The post-processing dimension acquisition unit 40 corrects the first post-processing dimension Wb1 of the second cutting track 12 of the next object to be processed, based on the first post-processing dimension Wb1 and the second post-processing dimension Wb2 of the object to be processed. Specifically, the post-processing dimension acquisition unit 40 calculates the error rate B (=Wb2 / Wb1) based on the first post-processing dimension Wb1 and the second post-processing dimension Wb2 of the object to be processed. The post-processing dimension acquisition unit 40 corrects the first post-processing dimension Wb1 of the next object to be processed by multiplying it by the error rate B. Furthermore, the closing interval correction unit 41 corrects the closing interval for the second cutting track 12, which is the next object to be processed, based on the pre-processing dimension Wa and the corrected first post-processing dimension Wb1.

[0063] (Method 5 for obtaining dimensions after processing) In the method 5 for obtaining the post-processing dimension, the post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb for each of the second cutting tracks 12 before performing the second laser processing. Specifically, the post-processing dimension acquisition unit 40 first controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the edge position of the second cutting track 12e, which is the initial processing target. The post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb of the second cutting track 12e based on the detected edge position. The second processing control unit 42 performs laser processing on the second cutting track 12e based on the closed interval corrected by the closed interval correction unit 41 according to the post-processing dimension Wb.

[0064] Subsequently, when the second laser processing of the second cutting path 12j (where j is an integer greater than 1 indicating the processing sequence) by the second processing control unit 42 ends, the post-processing dimension acquisition unit 40 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the edge position of the second cutting path 12(j+1). The post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb of the second cutting path 12(j+1) based on the detected edge position. That is, the control device 30 performs the acquisition of the post-processing dimension Wb by the post-processing dimension acquisition unit 40, the correction of the closing interval by the closing interval correction unit 41, and the laser processing by the second processing control unit 42 for each second cutting path 12.

[0065] (The function of the first implementation method) In the wafer processing system 20, the control device 30 acquires the pre-processing dimension Wa and the post-processing dimension Wb for each second dicing track 12 before the first laser processing. Furthermore, the control device 30 performs laser processing on each second dicing track 12 after correcting the closing range based on the pre-processing dimension Wa and the post-processing dimension Wb.

[0066] The function and effects of the wafer processing system and wafer processing method of the first embodiment are explained. (1-1) The wafer processing system 20 performs a first laser processing and a second laser processing. In the first laser processing, laser L1 is irradiated from the laser irradiation unit 22 along the first dicing path 11 to form a laser processing mark 15 inside the wafer 10. In the second laser processing, after the first laser processing, laser L1 is irradiated from the laser irradiation unit 22 along the second dicing path 12 that intersects with the first dicing path 11, with the intersection 13 of the intersection with the first dicing path 11 being a closed section of laser L1, to form a laser processing mark 15 inside the wafer 10.

[0067] The wafer processing system 20 includes a coaxial AF device 24 capable of detecting the edge position of the wafer 10, a relative movement mechanism 23 capable of relative movement between the wafer 10 and the coaxial AF device 24, and a control device 30 for controlling the various elements of the wafer processing system 20.

[0068] For each second dicing track 12, the control device 30 acquires the pre-processing dimension Wa before the first laser processing, and acquires the post-processing dimension Wb based on the edge position of the wafer 10 after the first laser processing. Furthermore, the control device 30 is configured to correct the closing interval for each second dicing track 12 based on the expansion amount ΔW calculated from the post-processing dimension Wb and the pre-processing dimension Wa.

[0069] According to this wafer processing system 20 and wafer processing method, the pre-processing dimension Wa and the post-processing dimension Wb are obtained based on the edge position of the wafer 10 detected by the coaxial AF device 24. Therefore, compared to, for example, obtaining the dimensions before and after the first laser processing by image processing of the wafer 10's photographic data, the accuracy of the pre-processing dimension Wa and the post-processing dimension Wb can be improved. Furthermore, by using such pre-processing dimensions Wa and post-processing dimensions Wb, the closed region can be corrected with good accuracy.

[0070] (1-2) A coaxial AF device 24 is provided on the laser irradiation unit 22. That is, the relative movement mechanism 23 is configured to move the coaxial AF device 24 and the laser irradiation unit 22 relative to the wafer 10. Furthermore, in the method 2 for obtaining the pre-processing dimension, the control device 30 is configured to obtain the pre-processing dimension Wa of the second cutting track 12 based on the edge position of the first cutting track 11.

[0071] With this structure, the edge position of the first cutting track 11 can be detected based on the height position H detected by the coaxial AF device 24 during the first laser processing. Therefore, the first laser processing for each first cutting track 11 and the acquisition of the pre-processing dimensions Wa for each second cutting track 12 can be performed in parallel. As a result, the acquisition of the pre-processing dimensions Wa can be performed efficiently, thus suppressing the reduction in production capacity.

[0072] (1-3) In method 3 for obtaining the pre-processing dimension, the control device 30 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the edge position of the second cutting track 12. Furthermore, the control device 30 is configured to obtain the pre-processing dimension Wa based on the edge position detected by the coaxial AF device 24 for the second cutting track 12.

[0073] Based on this structure, the edge position of the second cutting track 12 in the set closed interval is directly detected to obtain the pre-processing dimension Wa, thus improving the accuracy of the pre-processing dimension Wa.

[0074] (1-4) In method 4 for obtaining the pre-processing dimension, the control device 30 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the edge position of a portion of the second cutting track 12. Furthermore, the control device 30 is configured to obtain the pre-processing dimension Wa of the entire second cutting track 12 based on the edge position detected by the coaxial AF device 24 for this portion of the second cutting track 12.

[0075] With this structure, the pre-processing dimension Wa can be obtained efficiently. Furthermore, the more second cutting tracks 12 are used for inspection, the higher the accuracy of the pre-processing dimension Wa can be for all second cutting tracks 12.

[0076] (1-5) In methods 1 and 2 for obtaining the post-processed dimension, after the first laser processing of all the first cutting tracks 11 is completed, the control device 30 controls the relative movement mechanism 23 and the coaxial AF device 24 by detecting the edge position of at least one of the second cutting tracks 12. Furthermore, the control device 30 is configured to obtain the post-processed dimension Wb of all the second cutting tracks 12 based on the edge position detected by the coaxial AF device 24 for at least one of the second cutting tracks 12. With this structure, the post-processed dimension Wb is obtained by directly detecting the edge position of the second cutting track 12 within the set closed interval, thus improving the accuracy of the post-processed dimension Wb.

[0077] (1-6) In method 1 for obtaining the post-processed dimension, the control device 30 is configured to detect the edge positions of all the second cutting tracks 12. As a result, the post-processed dimension Wb of the second cutting track 12 can be obtained with higher accuracy.

[0078] (1-7) In method 2 for obtaining the post-processed dimensions, the control device 30 is configured to obtain the post-processed dimensions Wb of all the second cutting tracks 12 based on the edge positions detected for a portion of the second cutting tracks 12. Therefore, the post-processed dimensions Wb of all the second cutting tracks 12 can be obtained efficiently.

[0079] (1-8) In the method 3 for obtaining the post-processed dimensions, the control device 30 calculates the post-processed dimensions Wb of the other second cutting tracks 12 based on the expansion rate A of a specific second cutting track 12.

[0080] Based on this structure, the time required to obtain the post-processed dimension Wb can be shortened. Furthermore, by designating a specific second cutting path 12 as second cutting path 12c, the accuracy of the post-processed dimension Wb of the other second cutting paths 12 can be improved. Additionally, by designating a specific second cutting path 12 as second cutting path 12e, the time required to obtain the post-processed dimension Wb of the other second cutting paths 12 can be further reduced.

[0081] (1-9) In the method 4 for obtaining the post-processed dimension, the control device 30 corrects the first post-processed dimension Wb1 of the second cutting track 12, which is the next processing target, based on the first post-processed dimension Wb1 obtained using the methods 1-3 for obtaining the post-processed dimension and the second post-processed dimension Wb2 obtained based on the edge position obtained during the second laser processing of the processing object. The control device 30 corrects the closing interval for the second cutting track 12, which is the next processing target, based on the pre-processed dimension Wa and the corrected first post-processed dimension Wb1.

[0082] Based on this structure, the first post-processed dimension Wb1 of the next processed object is corrected based on the error of the post-processed dimension Wb in the processed object, thus further improving the accuracy of the closed interval of the next processed object.

[0083] (1-10) When the method 5 for obtaining the post-processed dimensions is used, the control device 30 is configured to perform the acquisition of the post-processed dimension Wb, the correction of the closed interval, and the second laser processing for each second cutting path 12.

[0084] With this structure, the post-processing dimension Wb can be obtained before the second laser processing of the workpiece. As a result, even if the expansion amount changes due to the time elapsed from the first laser processing to the second laser processing, and even if the expansion amount changes due to the second laser processing of other second cutting tracks 12, it can be accurately corrected to the closed range of the second cutting track 12 of the workpiece.

[0085] (Second Implementation) Reference Figure 9 and Figure 10 A second embodiment of the wafer processing system and wafer processing method will be described. Although the main structure of the wafer processing system in the second embodiment is the same as that in the first embodiment, the method for calculating the expansion amount differs. Therefore, in the second embodiment, the parts that differ from those in the first embodiment will be described in detail, while the parts that are the same as those in the first embodiment will be labeled with the same reference numerals, and their detailed descriptions will be omitted.

[0086] like Figure 9 As shown, the wafer processing system 20 includes a laser irradiation unit 22 and a front AF device 50. The laser irradiation unit 22 and the front AF device 50 are supported by a common frame 51. The frame 51 is configured to move along the Y and Z directions via a relative movement mechanism 23. That is, the laser irradiation unit 22 and the front AF device 50 are configured to move as a single unit. Furthermore, in Figure 9 Although the illustration is omitted, a coaxial AF device 24 and a camera 25 are provided in the laser irradiation section 22.

[0087] The front AF device 50 is configured to irradiate AF light L3 at a position a predetermined distance forward (in the -X direction) from the irradiation position of laser L1 to detect the height position H of the surface of the wafer 10. That is, the front AF device 50 is configured to detect the height position H of the surface before the irradiation of laser L1 during the second laser processing.

[0088] like Figure 10As shown, in this structure, the pre-processing dimension acquisition unit 39 uses the same method as pre-processing dimension acquisition methods 2 to 4 to detect the edge position (coordinates) of the leading edge 52a of each second cutting track 12. The pre-processing dimension acquisition unit 39 can use either the coaxial AF device 24 or the front AF device 50 in detecting the leading edge 52a. When the worktable 21 is moved by the relative movement mechanism 23, the pre-processing dimension acquisition unit 39 corrects the edge position (coordinates) of the leading edge 52a of each second cutting track 12 according to this movement, and acquires the corrected edge position as the pre-processing dimension (Xa, Ya).

[0089] The post-processing dimension acquisition unit 40 controls the forward AF device 50 during the second laser processing. The post-processing dimension acquisition unit 40 detects the edge position (coordinates) of the leading edge 52b of the second cutting path 12, which has shifted due to expansion, and acquires this detected edge position as the post-processing dimension (Xb, Yb). That is, the post-processing dimension acquisition unit 40 will... Figure 10 The edge position detected before the laser L1 is irradiated by the laser processing trace 15, which is represented by a double-dotted line, i.e., the laser processing trace 15 arranged along the X direction, is used as the post-processing dimension (Xb, Yb).

[0090] The closing interval correction unit 41 obtains the difference between the position of the leading edge 52a and the position of the leading edge 52b in the X direction as the expansion amount ΔW (=|Xb-Xa|), and corrects the closing interval based on the obtained expansion amount ΔW.

[0091] Here, when the first laser processing is performed sequentially from the first kerf 11 at one end of the second direction D2 to the first kerf 11 at the other end, the wafer 10 expands towards the other end instead of towards one end of the second direction D2. When the first laser processing is performed in this sequence, the shut-off interval correction unit 41 corrects the shut-off interval for each second kerf 12 based on the average expansion amount ΔWμ (=ΔW / n) obtained by dividing the expansion amount ΔW by the number of intersections n with the first kerf 11.

[0092] Furthermore, if the first laser processing is performed sequentially from the first kerf 11 at one end of the second direction D2 to the first kerf 11 at the center, and then sequentially from the first kerf 11 at the other end of the second direction D2 to the first kerf 11 at the center, the wafer 10 will expand in both directions of the second direction D2. When the first laser processing is performed in this order, the shut-off interval correction unit 41 expands in both the +X and -X directions by an expansion amount ΔW. For each second kerf 12, the shut-off interval is corrected based on the average expansion amount ΔWμ (=ΔW×2 / n) obtained by dividing the expansion amount ΔW×2 by the number of intersections n with the first kerf 11.

[0093] In addition to the effects described in (1-1) above, the wafer processing system and wafer processing method according to the second embodiment can achieve the following effects. (2-1) The wafer processing system 20 includes a front AF device 50, which is configured to move relative to the worktable 21 together with the laser irradiation unit 22, and detect the edge position of the wafer 10 by using the position in front of the irradiation position of the laser L1 as the detection position. The control device 30 detects the edge position of the leading edge 52a of the second kerf 12 before the first laser processing as the pre-processing dimensions (Xa, Ya). During the second laser processing, the control device 30 controls the front AF device 50 by detecting the edge position of the leading edge 52b of the second kerf 12 that will be processed as the post-processing dimensions (Xb, Yb). That is, the control device 30 obtains the post-processing dimensions (Xb, Yb) before irradiating the predetermined forming line with the laser L1. Furthermore, the control device 30 irradiates the processed object with the laser L1 after correcting the closed area of ​​the processed object based on the pre-processing dimensions (Xa, Ya) and the post-processing dimensions (Xb, Yb).

[0094] According to this structure, during the second laser processing of the workpiece, the edge position of the leading edge 52b detected before irradiating the predetermined forming line of the laser processing mark 15 with laser L1 can be obtained as the post-processing dimensions (Xb, Yb). As a result, the time required to obtain the post-processing dimensions (Xb, Yb) can be shortened. In addition, since the post-processing dimensions (Xb, Yb) are obtained just before irradiating the predetermined forming line with laser L1, even if the expansion amount changes due to the time elapsed from the first laser processing to the second laser processing, the closed area of ​​the workpiece can be accurately corrected.

[0095] (Third Implementation) Reference Figure 11 and Figure 12A third embodiment of the wafer processing system and wafer processing method will be described. Although the main structure of the wafer processing system in the third embodiment is the same as that in the first embodiment, the method for obtaining the post-processing dimensions differs. Therefore, in the third embodiment, the parts that differ from those in the first embodiment will be described in detail, while the parts that are the same as those in the first embodiment will be labeled with the same reference numerals, and their detailed descriptions will be omitted.

[0096] like Figure 11 As shown, the wafer processing system 20 includes a laser irradiation unit 22 and a side AF device 55. The laser irradiation unit 22 and the side AF device 55 are supported by a common frame 51. The frame 51 is configured to move along the Y and Z directions via a relative movement mechanism 23. That is, the laser irradiation unit 22 and the side AF device 55 are configured to move as a single unit. Furthermore, in Figure 11 Although the illustration is omitted, a coaxial AF device 24 and a camera 25 are provided in the laser irradiation unit 22.

[0097] The side-mounted AF device 55 is configured to irradiate AF light L4 at a position away from the indexing interval Ly in the +Y direction from the irradiation position of laser L1, in order to detect the height position H of the surface of the wafer 10. The indexing interval Ly is the interval between two adjacent second dicing tracks 12 in the Y direction. That is, the side-mounted AF device 55 is configured to detect the height position H of the surface of the next workpiece during the second laser processing of the workpiece. In addition, the side-mounted AF device 55 is preferably supported by the frame 51 so that it can move along the Y direction. With this structure, the position of the side-mounted AF device 55 can be adjusted according to the indexing interval Ly of the wafer 10.

[0098] In this structure, the pre-processing dimension acquisition unit 39 uses pre-processing dimension acquisition methods 1 to 4 to acquire the pre-processing dimension Wa. like Figure 12 As shown, during the second laser processing of the second cutting path 12j, which is the processing target, the post-processing dimension acquisition unit 40 controls the side AF device 55 by detecting the height position H of the surface of the second cutting path 12(j+1), which is the next processing target. The post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb of the second cutting path 12(j+1) based on the edge position of the second cutting path 12(j+1) detected by the side AF device 55. The closing interval correction unit 41 corrects the closing interval of the second cutting path 12(j+1) based on the pre-processing dimension Wa and the post-processing dimension Wb thus acquired.

[0099] According to the wafer processing system and wafer processing method of the third embodiment, in addition to the effects described above (1-1), the following effects can also be obtained. (3-1) In the wafer processing system 20, the side AF device 55 is configured to detect the edge position of the second dicing 12(j+1), which is adjacent to the second dicing 12j and is the next processing target. During the second laser processing of the second dicing 12j, the control device 30 controls the side AF device 55 by detecting the edge position of the second dicing 12(j+1). Furthermore, the control device 30 is configured to obtain the processed dimension Wb of the second dicing 12(j+1) based on the edge position of the second dicing 12(j+1) detected by the side AF device 55.

[0100] With this structure, the second laser processing of the second cutting track 12j and the acquisition of the post-processing dimension Wb of the second cutting track 12(j+1) can be performed in parallel. As a result, the acquisition of the post-processing dimension Wb can be performed efficiently, thereby suppressing the reduction in production capacity.

[0101] (Fourth Implementation) Reference Figure 13 and Figure 14 A fourth embodiment of the wafer processing system and method will be described. While the main structure of the wafer processing system in the fourth embodiment is the same as that in the first embodiment, it differs in the formation of multi-layer laser processing marks on the wafer. Therefore, in the fourth embodiment, the parts that differ from those in the first embodiment will be described in detail, while the same reference numerals will be used for the parts that are the same as those in the first embodiment, and their detailed descriptions will be omitted.

[0102] like Figure 13 As shown, the second laser processing includes lower-layer laser processing for forming a lower-layer processing mark 15A as a laser processing mark, and upper-layer laser processing for forming an upper-layer processing mark 15B as a laser processing mark above the lower-layer processing mark 15A. In this case, if the intersection 13 is not irradiated with laser L1 as a closed interval, the thermal damage associated with laser L1 irradiation of the lower-layer processing mark 15A, which is closer to the device surface 10a, as shown by arrow 60, may sometimes converge within the first cutting path 11. On the other hand, the thermal damage associated with laser L1 irradiation of the upper-layer processing mark 15B, which is farther from the device surface 10a, as shown by arrow 61, may not completely converge within the intersection 13, sometimes affecting various devices. This phenomenon occurs depending on processing conditions 31, etc.

[0103] like Figure 14As shown, in the fourth embodiment, under the condition that the above-described phenomenon occurs, in the second laser processing, the lower-level laser processing is performed without setting the intersection 13 as a closed interval, and the upper-level laser processing is performed with the intersection 13 set as a closed interval. Furthermore, in the upper-level laser processing, the processing start position can also be set at the position where the laser irradiation unit 22 is arranged on the -X direction side of the second cutting track 12 that is the processing target, and the processing completion position can also be set at the position where the laser irradiation unit 22 is arranged on the +X direction side of the second cutting track 12 that is the processing target.

[0104] In this structure, the shut-off interval setting unit 38 sets the shut-off interval for upper laser processing in each of the second cutting channels 12 based on the wafer position and wafer information 32. The pre-processing dimension acquisition unit 39 acquires the pre-processing dimension Wa using the pre-processing dimension acquisition methods 1 to 4 described above.

[0105] During the lower-level laser processing performed by the second processing control unit 42, the post-processing dimension acquisition unit 40 detects the edge position of the second cutting path 12 based on the height position H detected by the coaxial AF device 24. Furthermore, the post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb of the second cutting path 12 based on this detected edge position. The closing interval correction unit 41 corrects the closing interval during the upper-level laser processing based on the expansion amount ΔW between the pre-processing dimension Wa and the post-processing dimension Wb.

[0106] In addition to the effects described in (1-1) above, the wafer processing system and wafer processing method according to the fourth embodiment can also achieve the following effects. (4-1) In the wafer processing system 20, as a second laser processing, a lower-layer laser processing is performed in which a lower-layer processing mark 15A is formed without setting the intersection 13 as a closed interval, and an upper-layer laser processing is performed in which an upper-layer processing mark 15B is formed above the lower-layer processing mark 15A with the intersection 13 set as a closed interval. The control device 30 controls the coaxial AF device 24 in the lower-layer laser processing performed by the second processing control unit 42 by detecting the edge position of the workpiece. The control device 30 obtains the post-processing dimension Wb of the workpiece based on the edge position of the workpiece detected by the coaxial AF device 24 in the lower-layer laser processing. Furthermore, the control device 30 is configured to correct the closed interval in the upper-layer laser processing before irradiating the predetermined forming line with laser L1, based on the pre-processing dimension Wa and the post-processing dimension Wb.

[0107] With this structure, lower-level laser processing and the acquisition of the post-processing dimension Wb can be performed in parallel. As a result, laser processing of the wafer 10 can be performed without reducing productivity.

[0108] The first to fourth embodiments can be implemented with modifications as follows. The first to fourth embodiments and the following modifications can be combined with each other within the scope of technical non-contradiction.

[0109] Methods 1-4 for obtaining dimensions before processing and methods 1-5 for obtaining dimensions after processing can be combined as much as possible. In the first to third embodiments, the wafer processing system 20 forms laser processing marks 15 at the same position in the Z direction along each dicing track 11, 12 on the wafer 10. However, the wafer processing system 20 may also be a structure that forms multiple laser processing marks 15 at different positions in the Z direction along each dicing track 11, 12.

[0110] In the wafer processing system 20 of the second embodiment, a front AF device 50 is provided. This front AF device 50 is configured to move relative to the stage 21 together with the laser irradiation unit 22, and to detect the edge position of the wafer 10 by using the position in front of the irradiation position of the laser L1 as the detection position. The wafer processing system 20 can also use the front AF device 50 to implement methods 2 to 4 for obtaining dimensions before processing and methods 1 to 5 for obtaining dimensions after processing.

[0111] In method 4 for obtaining the post-processed dimensions, the first post-processed dimension Wb1 of the second cutting track 12(j+1), which is the next processing target, is corrected based on the first post-processed dimension Wb1 and the second post-processed dimension Wb2 of the second cutting track 12j, which is the processing target. Furthermore, the closing interval of the second cutting track 12(j+1) is corrected based on this corrected first post-processed dimension Wb1. However, the correction of the closing interval of the second cutting track 12(j+1) based on the pre-processed dimension Wa and the post-processed dimension Wb of the second cutting track 12j can also be performed as follows.

[0112] That is, the post-processing dimension acquisition unit 40 acquires the post-processing dimension Wbj of the second cutting track 12j based on the edge position detected by the coaxial AF device 24 during the second laser processing of the second cutting track 12j. The post-processing dimension acquisition unit 40 calculates the expansion ratio A2j (=Wbj / Waj) obtained based on the pre-processing dimension Waj and the post-processing dimension Wbj of the second cutting track 12j. Furthermore, the post-processing dimension acquisition unit 40 acquires the post-processing dimension Wb(j+1) of the second cutting track 12(j+1) by multiplying the pre-processing dimension Wa(j+1) of the second cutting track 12(j+1) by the expansion ratio A2. The closing interval correction unit 41 corrects the closing interval for the second cutting track 12(j+1) based on the pre-processing dimension Wa(j+1) and the post-processing dimension Wb(j+1). According to this structure, the post-processing dimension Wb(j+1) of the second cutting track 12(j+1) can be acquired by the second laser processing performed on the second cutting track 12j. That is, it can efficiently obtain the processed dimension Wb(j+1).

[0113] Alternatively, a rear AF device can be installed in the wafer processing system 20. This rear AF device is configured to move relative to the stage 21 together with the laser irradiation unit 22, and to detect the edge position of the wafer 10 by using the area behind the irradiation position of the laser L1 as the detection position.

[0114] Based on this structure, method 6 for obtaining the post-processed dimension can detect the edge position after the first laser processing during the first laser processing, and obtain the post-processed dimension Wb based on the edge position. As a result, the post-processed dimension Wb can be obtained efficiently, thus suppressing the reduction in production capacity.

[0115] In the fourth embodiment, a lower layer processing mark 15A and an upper layer processing mark 15B are formed on the wafer 10. However, the wafer processing system 20 may also have a structure in which three or more laser processing marks are formed at different positions in the Z direction on the wafer 10. In this case, the wafer processing system 20 performs lower layer laser processing on the laser processing marks located within the area where the thermal damage associated with laser L1 converges to the intersection 13. Explanation of reference numerals in the attached figures

[0116] 10…Wafer, 10a…Device surface, 11…First kerf, 12…Second kerf, 13…Intersection, 15…Laser processing marks, 15A…Lower layer processing marks, 15B…Upper layer processing marks, 16…Cutting tape, 20…Wafer processing system, 21…Worktable, 22…Laser irradiation unit, 23…Relative movement mechanism, 24…Coaxial AF device, 25…Camera, 26…Laser emission unit, 27…Condenser lens, 28…Dial separator, 30… Control device, 31…processing conditions, 32…wafer information, 36…alignment detection unit, 37…first processing control unit, 38…closed interval setting unit, 39…pre-processing dimension acquisition unit, 40…post-processing dimension acquisition unit, 41…closed interval correction unit, 42…second processing control unit, 45…approximate curve, 50…front AF device, 51…frame, 52a…leading edge, 53b…leading edge, 55…side AF device, 60, 61…arrows.

Claims

1. A wafer processing system configured to perform: The first laser processing involves irradiating a laser from a laser irradiation unit along multiple first cutting paths to form laser processing marks inside the wafer; and In the second laser processing, after the first laser processing, laser processing marks are formed inside the wafer by irradiating the laser from the laser irradiation section along a plurality of second cutting paths that intersect with the plurality of first cutting paths, with the intersections of the intersections with the first cutting paths designated as closed zones for the laser. The wafer processing system includes: The detection unit is capable of detecting the edge position of the wafer; The relative moving part enables relative movement between the wafer and the detection part; and The control unit controls all elements of the wafer processing system. The control unit is configured as follows: The dimensions before processing are obtained for the plurality of second cutting paths prior to the first laser processing; The relative moving part and the detection part are controlled in a manner that the post-processing dimensions of the second cutting path are obtained based on the edge position of the wafer after the first laser processing; Based on the post-processing dimensions and the pre-processing dimensions, the expansion amount of each of the plurality of second cutting paths is calculated; as well as The closing interval is modified based on the expansion amount for each of the plurality of second cutting channels.

2. The wafer processing system according to claim 1, wherein, The relative movement section is configured to cause the detection section and the laser irradiation section to move relative to the wafer. The control unit is configured to control the relative movement unit and the detection unit by detecting the edge positions of the plurality of first cutting tracks, and to obtain the pre-processing dimensions based on the edge positions of the plurality of first cutting tracks.

3. The wafer processing system according to claim 1, wherein, The control unit is configured to control the relative movement unit and the detection unit by detecting the edge positions of the plurality of second cutting tracks, and to obtain the pre-processing dimensions based on the edge positions detected by the detection unit for the plurality of second cutting tracks.

4. The wafer processing system according to claim 1, wherein, The control unit is configured as follows: After the first laser processing, the detection unit and the relative movement unit are controlled in a manner that detects at least one edge position among the plurality of second cutting paths; as well as The processed dimensions are obtained based on the edge position detected by the detection unit for at least one of the plurality of second cutting paths.

5. The wafer processing system according to claim 1, wherein, When the second cutting path that will become the object of the second laser processing is designated as the processing object, and the second cutting path adjacent to the processing object before processing is designated as the next processing object, The relative movement section is configured to cause the detection section and the laser irradiation section to move relative to the wafer. The detection unit is configured to detect the edge position of the workpiece. The control unit is configured as follows: During the second laser processing, the detection unit is controlled to obtain the post-processing dimensions of the object by detecting the edge position of the object being processed; and The closed range of the processed object or the next processed object is corrected based on the pre-processing dimensions and post-processing dimensions of the processed object.

6. The wafer processing system according to claim 5, wherein, When the post-processed dimension obtained by the control unit before the second laser processing is set as the first post-processed dimension... The control unit is configured as follows: The detection unit is controlled to obtain the second post-processing dimension of the workpiece by detecting the edge position of the workpiece during the second laser processing; and The closing range of the next processed object is corrected based on the first and second post-processed dimensions of the processed object.

7. The wafer processing system according to claim 1, wherein, When the second cutting path that will become the object of the second laser processing is designated as the processing object, and the second cutting path adjacent to the processing object before processing is designated as the next processing object, The relative movement section is configured to cause the detection section and the laser irradiation section to move relative to the wafer. The detection unit is configured to detect the edge position of the next object to be processed during the second laser processing of the object being processed.

8. A wafer processing method, comprising: The first laser processing involves irradiating a laser from a laser irradiation unit along multiple first cutting paths to form laser processing marks inside the wafer. as well as In the second laser processing, after the first laser processing, laser processing marks are formed inside the wafer by irradiating the laser from the laser irradiation section along a plurality of second cutting paths that intersect with the plurality of first cutting paths, with the intersections of the intersections with the first cutting paths designated as closed zones for the laser. A wafer processing system capable of performing the first laser processing and the second laser processing includes: The detection unit is capable of detecting the edge position of the wafer; The relative moving part enables relative movement between the wafer and the detection part; and The control unit controls all elements of the wafer processing system. The control unit performs the following operations: The relative movement unit and the detection unit are controlled in such a way that the dimensions before processing are obtained for each of the plurality of second cutting paths based on the edge position of the wafer before the first laser processing; The relative moving part and the detection part are controlled in such a way that the processed dimensions are obtained for each of the plurality of second cutting paths based on the edge position of the wafer after the first laser processing; The expansion amount of each of the plurality of second cutting paths is calculated based on the post-processing dimensions and the pre-processing dimensions; and For each of the plurality of second cutting channels, the closing interval is modified based on the expansion amount.

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