Work processing method
The workpiece processing method efficiently reads identification marks by storing the positional relationship between a reference point and the mark, addressing the challenge of shifts in orientation and position, thereby enhancing productivity.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- DISCO CORP
- Filing Date
- 2022-03-16
- Publication Date
- 2026-05-29
AI Technical Summary
Existing methods struggle with efficiently reading identification marks on workpieces due to shifts in orientation and position, leading to errors and reduced productivity, especially with small identification marks.
A workpiece processing method that involves storing the positional relationship between a reference point and the identification mark, detecting the reference point first, and then using this relationship to efficiently read the identification mark, even if the workpiece's position or orientation shifts.
Enables quick and efficient reading of identification marks, even with small sizes, by detecting a reference point such as the workpiece center, notch, or characteristic pattern, reducing errors and improving productivity.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a method for processing a workpiece that records and manages identification information for identifying the workpiece.
Background Art
[0002] In recent years, for production management, it has been required to be able to track for each workpiece what processes have been performed on which device. Usually, identification marks such as ID (Identification), barcodes, or character strings are printed on the workpiece, and the information of the workpiece and the history of the processes performed are linked and recorded by reading the identification mark before and after processing the workpiece (see, for example, Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] When automatically reading an identification mark, since the position of the identification mark is the same for workpieces in the same lot, the position for reading the identification mark is determined in advance. However, in reality, since the orientation and position of the workpiece shift each time, if the identification mark has shifted from the pre-determined position, there is a risk that the identification mark cannot be detected, an error occurs, and the process stops, or it is necessary to repeatedly perform the reading operation while changing the reading position until the identification mark can be detected, resulting in poor productivity. In particular, in recent years, there has been a problem that the size of the identification mark is small, and it is difficult to detect if the workpiece has shifted.
[0005] The present invention has been made in view of such problems, and its object is to provide a method for processing a workpiece that can efficiently read an identification mark displayed on the workpiece. [Means for solving the problem]
[0006] To solve the above-mentioned problems and achieve the objective, the present invention provides a workpiece processing method comprising: a holding table for holding a workpiece; an imaging unit for imaging a workpiece held on the holding table; and a processing unit for processing a workpiece held on the holding table, wherein the workpiece processing method involves processing a workpiece on which an identification mark is displayed to identify the workpiece, and includes: a positional relationship storage step for storing the positional relationship between a reference point of the workpiece and the identification mark; a holding step for holding the workpiece on the holding table; and a reference point detection step for imaging the workpiece held on the holding table with the imaging unit and detecting the reference point. The system comprises a step, a reading step which detects the identification mark based on the positional relationship recorded in the positional relationship storage step, and reads the identification mark by imaging the identification mark with the imaging unit, a processing step which processes the workpiece, and an information recording step which associates and records the workpiece information indicated by the identification mark read in the reading step with processing information related to the processing step, wherein the reference point is one of the following: the center of the workpiece, a notch or orientation flat which is a mark indicating the crystal orientation of the workpiece and of which only one is formed on the outer edge of the workpiece, and a characteristic pattern which is of which only one is formed on the workpiece. The identification mark is 1 μm or larger and 10 μm or smaller. It is characterized by the following 。
[0007] The position and size of the identification mark are determined for each lot of workpieces, and after performing the positional relationship storage step for the first workpiece of the lot, the holding step, the reference point detection step, the reading step, the processing step, and the information recording step are performed for each workpiece in the same lot to be processed by the processing device. That's fine. [Effects of the Invention]
[0008] In this invention, the positional relationship between the workpiece's reference point and the identification mark is stored in the positional relationship storage step before processing the workpiece. In the reference point detection step, the reference point, which is easier to detect than the identification mark, is detected first. The identification mark is then detected using the positional relationship based on the reference point. Therefore, even if the workpiece's position or orientation is shifted, the identification mark can be read quickly and efficiently. Furthermore, in this invention, by setting the workpiece's reference point to the center of the workpiece, the reference point can be detected in exactly the same way even if the workpiece's orientation or position is shifted. Therefore, the identification mark can be read quickly and efficiently without being affected by shifts in the workpiece's position or orientation. [Brief explanation of the drawing]
[0009] [Figure 1] Figure 1 is a perspective view showing an example of the configuration of a processing apparatus that implements the workpiece processing method according to the embodiment. [Figure 2] Figure 2 is a top view showing an example of a workpiece that is processed by the workpiece processing method according to the embodiment of this invention. [Figure 3] Figure 3 is a flowchart showing the processing procedure of the workpiece processing method according to the present invention. [Figure 4] Figure 4 is a top view illustrating the positional relationship memory step shown in Figure 3. [Figure 5] Figure 5 is a top view illustrating the positional relationship memory step and the reference point detection step shown in Figure 3. [Figure 6] Figure 6 is a cross-sectional view illustrating the processing steps shown in Figure 3. [Figure 7] Figure 7 is a top view illustrating the positional relationship storage step of the workpiece processing method according to Modification 1. [Figure 8] Figure 8 is a top view illustrating the positional relationship storage step of the workpiece processing method according to Modification 2. [Figure 9] Figure 9 is a cross-sectional view illustrating an example of the processing steps of the workpiece processing method according to Modification 3. [Figure 10] Figure 10 is a cross-sectional view illustrating an example of the processing steps of the workpiece processing method according to Modification 4. [Modes for carrying out the invention]
[0010] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.
[0011] [Embodiment] A method for processing a workpiece according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is a perspective view showing an example of the configuration of a processing apparatus 1 that implements the workpiece processing method according to the embodiment. As shown in Figure 1, the processing apparatus 1 includes a holding table 10, an imaging unit 20, a processing unit 30, an X-axis movement unit 41, a Y-axis movement unit 42, a Z-axis movement unit 43, a display unit 51, an input unit 52, a notification unit 53, a cassette mounting table 61, a cleaning unit 62, a pair of rails 63, and a control unit 70.
[0012] Figure 2 is a top view showing an example of a workpiece 100 that is the target of processing according to the workpiece processing method according to the embodiment. As shown in Figure 2, the workpiece 100 is, for example, a disc-shaped semiconductor wafer or optical device wafer made of silicon, sapphire, silicon carbide (SiC), gallium arsenide, glass, etc. as the base material. As shown in Figure 2, the workpiece 100 has chip-sized devices 103 formed in regions demarcated by a plurality of division lines 102 formed in a grid pattern on a flat surface 101. In this embodiment, as shown in Figure 1, an adhesive tape 105 is attached to the back surface 104 on the back side of the surface 101 of the workpiece 100, and an annular frame 106 is attached to the outer edge of the adhesive tape 105, but the present invention is not limited to this. Also, as shown in Figures 1 and 2, a notch 107, which is a mark indicating the crystal direction of the workpiece 100, is formed on the outer edge of the workpiece 100, but the present invention is not limited to this, and instead of the notch 107, an orientation flat (orientation flat) which is a mark indicating the crystal direction of the workpiece 100 may be used. Station A flat surface may be formed, or a notch 107 or orientation flat may not be formed. In addition, in this invention, the workpiece 100 may be a rectangular package substrate having a plurality of resin-sealed devices, a ceramic plate, or a glass plate, etc.
[0013] As shown in Figure 2, each workpiece 100 has an identification mark 110, which indicates a workpiece ID, attached to the outer peripheral excess area 108 of the surface 101 of the workpiece 100 where the device 103 is not formed. In this embodiment, the outer diameter of the workpiece 100 is, for example, 200 mm (8 inches) or 300 mm (12 inches), while the size of the identification mark 110 is small, for example, between 1 μm and 10 μm. The position and size of the identification mark 110 are determined for each lot of workpiece 100.
[0014] The holding table 10 includes a disk-shaped frame body in which a recess is formed, and a disk-shaped suction portion fitted into the recess. The suction portion of the holding table 10 is formed of a porous ceramic or the like having a large number of porous holes, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). As shown in FIG. 1, the upper surface of the suction portion of the holding table 10 is a holding surface 11 on which the workpiece 100 is placed and the placed workpiece 100 is suction-held by the negative pressure introduced from the vacuum suction source. In the present embodiment, on the holding surface 11, the workpiece 100 is placed with the surface 101 facing upward, and the placed workpiece 100 is suction-held from the back surface 104 side via the adhesive tape 105. The holding surface 11 and the upper surface of the frame body of the holding table 10 are arranged on the same plane and are formed parallel to the XY plane which is a horizontal plane.
[0015] The holding table 10 is provided so as to be movable in the X-axis direction parallel to the horizontal direction by an X-axis direction moving unit 41. By moving the holding table 10 along the X-axis direction by the X-axis direction moving unit 41, the positions of the imaging unit 20 and the processing unit 30 on the surface 101 of the workpiece 100 held by the holding table 10 are moved in the X-axis direction (the direction opposite to the moving direction of the holding table 10). The holding table 10 is provided so as to be rotatable about a Z-axis which is parallel to the vertical direction and orthogonal to the XY plane by a rotation drive source (not shown).
[0016] The imaging unit 20 includes an imaging device that images the workpiece 100 held on the holding table 10. The imaging device is, for example, a CCD (Charge-Coupled Device) imaging device or a CMOS (Complementary MOS) imaging device. The imaging unit 20 images the surface 101 of the workpiece 100 before being processed by the processing unit 30 held on the holding table 10, sets a characteristic pattern serving as a reference for detecting the planned division line 102, obtains an image for performing teaching to register the distance from the pattern to the planned division line 102 with the control unit 70, and outputs the obtained image to the control unit 70. The imaging unit 20 images the surface 101 of the workpiece 100 before being processed by the processing unit 30 held on the holding table 10, obtains an image for performing alignment to align the workpiece 100 with the processing unit 30, and outputs the obtained image to the control unit 70. Further, the imaging unit 20 images the surface 101 of the workpiece 100 after being processed by the processing unit 30 held on the holding table 10, obtains an image for performing a process check to automatically confirm whether the processing on the workpiece 100 has been executed within a normal range, and outputs the obtained image to the control unit 70. In the present embodiment, the imaging unit 20 is fixed adjacent to the processing unit 30 and moves integrally with the processing unit 30.
[0017] The processing unit 30 processes the workpiece 100 held on the holding table 10. In the present embodiment, as shown in FIG. 1, the processing unit 30 includes a spindle to which a cutting blade is attached at the tip, and is a cutting unit that cuts the workpiece 100 held on the holding table 10. In the processing unit 30, the cutting blade attached to the tip of the spindle is subjected to a rotational operation around an axis parallel to one horizontal direction (the Y-axis direction in FIG. 1) by the rotational operation of the spindle, and cuts the workpiece 100 held on the holding table 10 along the planned division line 102. As shown in FIG. 1, the processing apparatus 1 includes two sets of the imaging unit 20 and the processing unit 30 (cutting unit), that is, a dicing machine with two spindles, a so-called facing dual type processing apparatus (cutting apparatus).
[0018] The processing unit 30 is provided with a Y-axis movement unit 42 so as to be movable in the Y-axis direction, which is parallel to the horizontal direction and perpendicular to the X-axis direction, and a Z-axis movement unit 43 so as to be movable in the Z-axis direction. The processing unit 30 moves relative to the workpiece 100 held on the holding table 10 along the Y-axis direction and the Z-axis direction, respectively, by the Y-axis movement unit 42 and the Z-axis movement unit 43.
[0019] The X-axis movement unit 41 moves the holding table 10 relative to the imaging unit 20 and the processing unit 30 along the X-axis. The Y-axis movement unit 42 and the Z-axis movement unit 43 move the imaging unit 20 and the processing unit 30 relative to the holding table 10 along the Y-axis and Z-axis, respectively. The X-axis movement unit 41, the Y-axis movement unit 42, and the Z-axis movement unit 43 are each configured to include, for example, a well-known ball screw rotatably mounted around the axes of the X, Y, and Z axes, a well-known pulse motor for rotating the ball screw around its axis, and a well-known guide rail for supporting the holding table 10 or the imaging unit 20 and processing unit 30 so that they can move in the X-axis, Y-axis, or Z-axis direction.
[0020] The X-axis movement unit 41, the Y-axis movement unit 42, and the Z-axis movement unit 43 each include an encoder that reads the rotational position of a pulse motor. Based on the rotational position of the pulse motor read by the encoder, they detect the relative positions of the holding table 10 and the imaging unit 20 and processing unit 30 in the X-axis, Y-axis, and Z-axis directions, and output the detected relative positions to the control unit 70. Note that the X-axis movement unit 41, the Y-axis movement unit 42, and the Z-axis movement unit 43 are not limited to a configuration in which the relative positions of the holding table 10 and the imaging unit 20 and processing unit 30 are detected by an encoder. They may also be configured with linear scales parallel to the X-axis, Y-axis, and Z-axis directions, and reading heads that are movable in the X-axis, Y-axis, and Z-axis directions by the X-axis movement unit 41, the Y-axis movement unit 42, and the Z-axis movement unit 43, respectively, and read the scales of the linear scales.
[0021] The display unit 51 is mounted on a cover (not shown) of the processing unit 1, with its display surface facing outwards. The display unit 51 displays to the operator in a visible manner the processing conditions of the processing unit 1, the imaging conditions of the imaging unit 20, the settings screen for various conditions such as teach, alignment, and processing checks, images captured by the imaging unit 20 for performing teach, alignment, and processing checks, and the confirmation results of the processing checks. The display unit 51 is composed of a liquid crystal display or the like. The display unit 51 is equipped with an input unit 52 used by the operator to input information related to the various conditions of the processing unit 1 and information related to the display of images. The input unit 52 provided on the display unit 51 is composed of at least one of a touch panel provided on the display unit 51 and a keyboard or the like. Note that the display unit 51 is not fixed to the processing unit 1, but can be provided on any communication device, and any communication device may be connected to the processing unit 1 wirelessly or wired.
[0022] The notification unit 53 is located above a cover (not shown) of the processing unit 1. In this embodiment, the notification unit 53 is a light-emitting unit composed of a light-emitting diode or the like, and notifies the operator of errors that occurred during imaging by the imaging unit 20 or processing by the processing unit 30, or the results of confirmation by processing checks, through the illumination, flashing, or color of the light-emitting unit. In this invention, the notification unit 53 is not limited to a light-emitting unit, but may also be a sound unit composed of a speaker or the like that emits sound, and notifies the operator of errors that occurred or the results of confirmation by processing checks, etc., through the sound of the sound unit.
[0023] The cassette mounting table 61 is a mounting table on which a cassette 65, which is a container for housing multiple workpieces 100, is placed, and the mounted cassette 65 is raised and lowered in the Z-axis direction. The washing unit 62 washes the workpieces 100 after processing and removes foreign matter such as processing debris attached to the workpieces 100. The processing apparatus 1 further comprises a transport unit (not shown), which transports the workpieces 100 between the holding table 10, the washing unit 62, a pair of rails 63, and the cassette 65.
[0024] The control unit 70 controls the operation of each component of the processing unit 1 to cause the processing unit 1 to perform various processes on the workpiece 100, including the workpiece processing method according to the embodiment. The control unit 70 includes a storage unit 71. The storage unit 71 stores images captured by the imaging unit 20 for performing teach, alignment, processing checks, etc., characteristic patterns (targets), XY coordinate information representing the positional relationship 130 between the reference point 120 of the workpiece 100 and the identification mark 110, XY coordinate information representing the distance and direction from the target to the planned division line 102, information of the workpiece 100 indicated by the identification mark 110, and processing information related to the processing of the workpiece 100.
[0025] The information for workpiece 100 specifically includes a lot number that is commonly assigned to workpieces of the same type, and a workpiece ID that indicates individual identification information set for each workpiece 100. The processing information related to the processing of workpiece 100 includes processing conditions that are set in advance before processing workpiece 100 and are referenced when processing workpiece 100, and processing data detected by any detectors provided on each component of the processing device 1 during and after processing workpiece 100.
[0026] The processing conditions include the type of processing unit 30, the type of processing tool attached to the processing unit 30, and the operating conditions of the processing tool. In this embodiment, the type of processing unit 30 is a cutting unit. In this embodiment, where the processing unit 30 is a cutting unit, the processing tool is a cutting blade. In this embodiment, where the processing unit 30 is a cutting unit, the operating conditions of the processing tool include the rotational speed of the spindle to which the cutting blade is fixed.
[0027] In this embodiment, where the processing unit 30 is a cutting unit, the processing data includes measurement data of the workpiece 100 during processing, such as the mount that fixes the cutting blade to the tip of the spindle, the vibration of the holding table 10 that holds the workpiece 100, the current and voltage of the motor that drives the spindle and the holding table 10, the torque generated when the spindle and the holding table 10 rotate and move, the load in the Z-axis direction applied to the holding table 10, the processing feed rate which is the relative movement speed of the processing unit 30 with respect to the holding table 10, the supply pressure, temperature and flow rate of the cutting fluid, and the thickness of the workpiece 100; images before and after processing captured by the imaging unit 20; information on traces generated during processing, such as the width, position, chipping, and adhesion of foreign matter of processing marks measured by image processing from the post-processing image; and changes when comparing images before and after processing.
[0028] In this embodiment, the control unit 70 includes a computer system. The computer system included in the control unit 70 has an arithmetic processing unit having a microprocessor such as a CPU (Central Processing Unit), a storage device having memory such as ROM (Read Only Memory) or RAM (Random Access Memory), and an input / output interface device. The arithmetic processing unit of the control unit 70 performs arithmetic processing according to a computer program stored in the storage device of the control unit 70 and outputs control signals for controlling the processing device 1 to each component of the processing device 1 via the input / output interface device of the control unit 70. In this embodiment, the function of the storage unit 71 is realized by the storage device of the control unit 70.
[0029] Figure 3 is a flowchart showing the processing procedure of a workpiece processing method according to an embodiment. The workpiece processing method according to an embodiment is an example of an operation performed by the processing device 1, and as shown in Figure 3, comprises a position relationship storage step 1001, a holding step 1002, a reference point detection step 1003, a reading step 1004, a processing step 1005, and an information recording step 1006.
[0030] Figure 4 is a top view illustrating the positional relationship storage step 1001 of Figure 3. Figure 5 is a top view illustrating the positional relationship storage step 1001 and the reference point detection step 1003 of Figure 3. The positional relationship storage step 1001 is a step of storing the positional relationship 130 between the reference point 120 of the workpiece 100 and the identification mark 110, as shown in Figure 4. In this embodiment, the positional relationship storage step 1001 is performed for the first workpiece 100 of the lot to be processed by the processing device 1.
[0031] The reference point 120 of the workpiece 100 is preferably one that is easier to locate than the identification mark 110, that is, one that is easy to detect even if the orientation or position of the workpiece 100 is shifted, and it is particularly preferable to set it at the center of the workpiece 100, as in this embodiment. The center of the workpiece 100 can be detected by detecting three points at any point on the outer edge of the workpiece 100, and even if the workpiece 100 is slightly shifted, the outer edge of the workpiece 100 is likely to be within the field of view of the imaging unit 20, making detection easy. In this embodiment, the reference point 120 of the workpiece 100 is the center of the workpiece 100, but the present invention is not limited to this, and may be any position on the surface 101 of the workpiece 100 that is easier to detect by the imaging unit 20 than the identification mark 110.
[0032] In the positional relationship memory step 1001, first, the control unit 70 transports the first workpiece 100 of the lot to be processed by the processing device 1 onto the holding table 10 using a transport unit (not shown), and has the holding table 10 hold this workpiece 100. Next in the positional relationship memory step 1001, the control unit 70 detects the coordinates of the center of the workpiece 100 held on the holding table 10 as the coordinates of the reference point 120. Specifically, as shown in Figure 5, the control unit 70 uses the imaging unit 20 to capture three points on the outer edge 121 of the workpiece 100 held on the holding table 10, calculates the coordinates of the three points on the outer edge 121 by image processing, calculates two perpendicular bisectors of any two points, and detects the coordinates of the intersection of the two perpendicular bisectors as the coordinates of the center of the workpiece 100.
[0033] In the positional relationship memory step 1001, after detecting the reference point 120 of the workpiece 100, the control unit 70 aligns the imaging unit 20 with the reference point 120 of the workpiece 100, and rotates the holding table 10 to adjust so that one of the two planned division lines 102 that intersect each other within the imaging area of the imaging unit 20 is parallel to the X-axis direction. With this adjustment, the imaging unit 20 is moved to a position where the identification mark 110 is in the center of the imaging area, and the storage unit 71 stores the distance and direction from the reference point 120 of the workpiece 100 to the identification mark 110 in XY coordinates. In this embodiment, these XY coordinates represent the positional relationship 130 between the reference point 120 of the workpiece 100 and the identification mark 110.
[0034] The positional relationship memory step 1001 may also be performed before or after the teach (teach step) in which the position of the division line 102 is registered in the storage unit 71 of the control unit 70. Specifically, in the teach step, first, with the workpiece 100 held in the holding table 10, the control unit 70 captures an image containing a characteristic pattern that serves as a reference for detecting the division line 102 using the imaging unit 20, and registers the pattern as a target. Next, in the teach step, the control unit 70 aligns the imaging unit 20 with the registered target (the pattern), and rotates the holding table 10 to adjust it so that one of the two division lines 102 that intersect each other within the imaging area of the imaging unit 20 is parallel to the X-axis direction. Then, the imaging unit 20 is moved to a position where the division line 102 is in the center of the imaging area, and the storage unit 71 stores the distance and direction from the registered target to the division line 102 in XY coordinates. The control unit 70 automatically performs alignment between the workpiece 100 and the processing unit 30 using the XY coordinates of the distance and direction from the target to the planned division line 102, which were stored in the memory unit 71 during the teach step. Note that the order of the position relationship storage step 1001 and the teach step does not matter.
[0035] In the positional relationship storage step 1001, the present invention is not limited to determining the positional relationship 130 between the reference point 120 and the identification mark 110 of the workpiece 100 on the processing device 1. The positional relationship 130 may also be determined on another device having a holding table and imaging unit similar to that of the processing device 1, or it may be determined from a design drawing of the workpiece 100. In the positional relationship storage step 1001, if the positional relationship 130 is determined outside of the processing device 1, the operator inputs the XY coordinates indicating the positional relationship 130 from the input unit 52, and the storage unit 71 of the control unit 70 stores the received XY coordinates as the positional relationship 130.
[0036] In this embodiment, after performing the positional relationship storage step 1001 for the first workpiece 100 of a lot to be processed by the processing device 1, the holding step 1002, reference point detection step 1003, reading step 1004, processing step 1005, and information recording step 1006 are performed for each workpiece 100 of the same lot to be processed by the processing device 1.
[0037] The holding step 1002 is the step of holding the workpiece 100 in the holding table 10. In the holding step 1002, the control unit 70 causes the workpiece 100 to be held in the holding table 10 in the same manner as in the position relationship storage step 1001 described above.
[0038] The reference point detection step 1003 is a step in which the workpiece 100 held on the holding table 10 in the holding step 1002 is imaged by the imaging unit 20 and a reference point 120 is detected. In the reference point detection step 1003, the center of the workpiece 100 is detected as the reference point 120 of the workpiece 100, in the same manner as in the position relationship storage step 1001 described above.
[0039] The reading step 1004 is a step in which the identification mark 110 is detected based on the positional relationship 130 recorded in the positional relationship memory step 1001, and the identification mark 110 is imaged by the imaging unit 20 and read. In the reading step 1004, the control unit 70 aligns the imaging unit 20 with the reference point 120 of the workpiece 100, and, similar to the positional relationship memory step 1001, rotates the holding table 10 to adjust so that one of the two planned division lines 102 that intersect each other within the imaging area of the imaging unit 20 is parallel to the X-axis direction, and then moves the imaging unit 20 based on the positional relationship 130, thereby easily moving it to a position where the identification mark 110 is within the imaging area. In the reading step 1004, the control unit 70 then images the identification mark 110 with the imaging unit 20 and reads the identification mark 110 to obtain information about the workpiece 100 indicated by the identification mark 110.
[0040] Figure 6 is a cross-sectional view illustrating processing step 1005 of Figure 3. Processing step 1005 is a step in which the control unit 70 processes the workpiece 100 with the processing unit 30. In this embodiment, where the processing unit 30 is a cutting unit, the control unit 70 refers to the processing conditions for the workpiece 100 stored in the storage unit 71 and, based on these processing conditions, supplies cutting fluid to the surface 101 of the workpiece 100 and, as shown in Figure 6, rotates the cutting blade around its axis by the rotational movement of the spindle, moving the cutting blade relative to the workpiece 100 held in the holding table 10 along the planned division line 102 and feeding it for processing, thereby cutting the workpiece 100 along the planned division line 102. In processing step 1005, the control unit 70 acquires processing information related to processing step 1005 along with processing the workpiece 100.
[0041] In processing step 1005, the control unit 70 acquires processing data related to processing step 1005 as follows. First, the control unit 70 uses the imaging unit 20 to image the surface 101 of the workpiece 100 before processing. Next, during the cutting process of the workpiece 100, the control unit 70 detects measurement data of the workpiece 100 during processing using any detector provided on each component of the processing apparatus 1. Then, the control unit 70 uses the imaging unit 20 to image the area of the surface 101 of the workpiece 100 after cutting, including the processing marks (cutting grooves), and measures and records the width, position, size, and number of chips of the cutting grooves by image processing. The control unit 70 also compares the image after processing with the image captured before processing by pattern matching, etc., to detect changes in the image before and after processing. The control unit 70 acquires the detected measurement data of the workpiece 100 during processing and the changes in the image before and after processing as processing data.
[0042] The information recording step 1006 is a step in which the information of the workpiece 100 indicated by the identification mark 110 read in the reading step 1004 is linked with the processing information related to the processing step 1005 and recorded. Specifically, in the information recording step 1006, the control unit 70 links the information of the workpiece 100 acquired in the reading step 1004, the processing conditions of the workpiece 100 referenced in the processing step 1005, and the processing data acquired in the processing step 1005, and stores them in the storage unit 71.
[0043] The workpiece processing method according to the embodiment having the above configuration stores the positional relationship 130 between the reference point 120 of the workpiece 100 and the identification mark 110 before processing the workpiece 100 in the positional relationship storage step 1001, first detects the reference point 120 which is easier to detect than the identification mark 110 in the reference point detection step 1003, and then detects the identification mark 110 by using the positional relationship 130 with respect to the reference point 120. This provides the effect of being able to read the identification mark 110 quickly and efficiently even if the position or orientation of the workpiece 100 is shifted. In particular, the workpiece processing method according to the embodiment makes it possible to easily detect the identification mark 110 with respect to the reference point 120 even when the size of the identification mark 110 is small, such as 1 μm to 10 μm, and detection tends to be difficult due to shifts in the position or orientation of the workpiece 100, thus making the above effect even more pronounced.
[0044] Conventionally, in order to read identification marks, it was common to install a separate imaging unit in the transport path or elsewhere, in addition to the imaging unit that images the workpiece held on the holding table, in order to read the identification marks. However, in the workpiece processing method according to this embodiment, the identification marks 110 are read on the holding surface 11, so the imaging unit 20 used for aligning and teaching the workpiece 100 can also be used to read the identification marks 110, thereby suppressing the increase in costs. Furthermore, since the imaging unit 20 used for aligning and teaching the workpiece 100 has a high magnification so that it can recognize the pattern of the device 103 of the workpiece 100, it can read the identification marks 110 even if they become small.
[0045] Furthermore, in the workpiece processing method according to the embodiment, since the reference point 120 of the workpiece 100 is set as the center of the workpiece 100, it is easier to detect even if the orientation or position of the workpiece 100 shifts relative to the reference point 120, thus making the above-mentioned effects even more pronounced.
[0046] [Variations 1, 2] The workpiece processing methods according to modified examples 1 and 2 of the present invention will be described based on the drawings. Figures 7 and 8 are top views illustrating the positional relationship storage step 1001 of the workpiece processing methods according to modified examples 1 and 2, respectively. In Figures 7 and 8, the same reference numerals are used for the same parts as in the embodiments, and their descriptions are omitted.
[0047] Modification 1, as shown in Figure 7, is the embodiment described above in which the reference point 120 of the workpiece 100 is changed to a notch 107. In Modification 1, if only one notch 107 is formed on the workpiece 100, it can be used as the reference point 120 of the workpiece 100. The notch 107 can be detected at any point on the outer edge of the workpiece 100 by moving the imaging unit 20 along the outer edge, and even if the workpiece 100 is slightly misaligned, the outer edge of the workpiece 100 is likely to be within the field of view of the imaging unit 20, making detection easy. In the position relationship storage step 1001 of Modification 1, the control unit 70 stores the position relationship 130-1 between the notch 107 and the identification mark 110 in the storage unit 71.
[0048] In another modification, the first modification involves changing the workpiece 100 on which the notch 107 is formed to a workpiece on which an orientation flat is formed, and changing the reference point 120 of the workpiece 100 to the orientation flat formed on the workpiece. In this case as well, if only one orientation flat is formed on the workpiece 100, it can be used as the reference point 120 of the workpiece 100. In this case as well, the orientation flat can be easily detected in the same way as the notch 107. In the position relationship storage step 1001 in this case, the control unit 70 stores the position relationship 130-1 between the orientation flat and the identification mark 110 in the storage unit 71.
[0049] Modification 2, as shown in Figure 8, is the embodiment described above in which the reference point 120 of the workpiece 100 is changed to a characteristic pattern 125. In Modification 2, if only one characteristic pattern 125 is formed on the workpiece 100, it can be used as the reference point 120 of the workpiece 100. The characteristic pattern 125 is registered as a target in the teach step and is sufficiently larger than the identification mark 110, so it can be detected more easily by the imaging unit 20 than the identification mark 110. In the position relationship storage step 1001 of Modification 2, the control unit 70 stores the position relationship 130-2 between the characteristic pattern 125 and the identification mark 110 in the storage unit 71.
[0050] The workpiece processing methods according to Modification 1 and 2 are both modified versions of the workpiece processing method according to the embodiment, in which the reference point 120 of the workpiece 100 is changed to a notch 107, orientation flat, or characteristic pattern 125 that can be similarly easily detected, and thus achieve the same effects as the embodiment.
[0051] [Modified examples 3, 4] The workpiece processing methods according to modified examples 3 and 4 of the present invention will be described based on the drawings. Figures 9 and 10 are cross-sectional views illustrating an example of processing step 1005 of the workpiece processing method according to modified examples 3 and 4, respectively. In Figures 9 and 10, the same reference numerals are used for parts that are the same as in the embodiments, and their descriptions are omitted.
[0052] Modification 3, as shown in Figure 9, is the embodiment described above in which processing unit 30 is changed to processing unit 30-1 (laser beam irradiation unit), processing step 1005 is changed to laser processing, and the processing information related to processing step 1005 acquired is changed accordingly. In other words, in Modification 3, the processing apparatus is a laser processing apparatus.
[0053] The processing unit 30-1 is a laser beam irradiation unit comprising a laser beam oscillator that generates a laser beam and a focuser that focuses the laser beam generated by the laser beam oscillator and irradiates it toward the workpiece 100. In processing step 1005, the control unit 70 performs a laser processing process in which the processing unit 30-1 irradiates the workpiece 100 with a laser beam to process the workpiece 100 with the laser beam. The laser processing process includes so-called ablation processing, in which the workpiece 100 is ablated (sublimated or evaporated) by irradiating it with a laser beam of an absorbent wavelength, and modified layer formation processing, in which a modified layer is formed inside the workpiece 100 by irradiating it with a laser beam of a penetrating wavelength.
[0054] In Modification 3, the processing conditions of the processing information related to processing step 1005, which are acquired in processing step 1005, include the type of processing unit 30-1, the type of laser beam irradiated by processing unit 30-1, and the laser beam irradiation conditions. In Modification 3, the type of processing unit 30-1 is a laser beam irradiation unit. The type of laser beam is the wavelength of the laser beam. The laser beam irradiation conditions include irradiation power, repetition frequency, defocus, etc.
[0055] In modification 3, the processing data of the processing information related to processing step 1005 acquired in processing step 1005 includes, but is not limited to, measurement data of the workpiece 100 during processing, such as the vibration of the light concentrator included in the laser beam irradiation unit, the irradiation power of the laser beam actually irradiated, the processing feed rate which is the relative movement speed of the processing unit 30-1 with respect to the holding table 10, and the thickness of the workpiece 100; images before and after processing captured by the imaging unit 20; information on traces generated during processing, such as the width, position, chipping, and adhesion of foreign matter of processing marks measured by image processing from the post-processing image; and changes obtained by comparing the images before and after processing.
[0056] Modification 4, as shown in Figure 10, is the embodiment described above in which the holding table 10 is changed to a holding table 10-2, the processing unit 30 is changed to a processing unit 30-2 (grinding unit), the processing of processing step 1005 is changed to a grinding process, and in accordance with this, the position relationship storage step 1001, the holding step 1002, the reference point detection step 1003, and the reading step 1004 are partially modified to change the processing information related to the processing step 1005 to be acquired. In other words, in Modification 4, the processing device is a grinding device.
[0057] In Modification 4, as shown in Figure 10, the holding surface 11-2 of the holding table 10-2 holds the workpiece 100 with its back surface 104 facing upward, and holds the placed workpiece 100 by suction from the front surface 101 side. The holding table 10-2 is made of a translucent material that allows the imaging unit 20 to image the workpiece 100 held on the holding table 10 from the holding surface 11 side. In Modification 4, the imaging unit 20 is located below or inside the holding table 10-2 and moves relative to the holding table 10-2. The imaging unit 20 images the front surface 101 of the workpiece 100 held on the holding table 10-2 from the holding surface 11-2 side.
[0058] Accordingly, in the modified example 4, the positional relationship storage step 1001, holding step 1002, reference point detection step 1003, and reading step 1004 are modified so that, in the above embodiment, the workpiece 100 is held by the holding table 10-2 from the surface 101 side, and the imaging unit 20 images the surface 101 of the workpiece 100 held by the holding table 10-2 from the holding surface 11 side.
[0059] The processing unit 30-2 is a grinding unit comprising a spindle with a grinding wheel, in which grinding wheels are arranged in a ring, attached to its tip. In processing step 1005, the control unit 70 performs a grinding process in which the workpiece 100 held on the holding table 10-2 is ground from the back surface 104 side by the processing unit 30-2.
[0060] In Modification 4, the processing conditions of the processing information related to processing step 1005, which are acquired in processing step 1005, include the type of processing unit 30-2, the type of processing tool attached to processing unit 30-2, and the operating conditions of the processing tool. In Modification 4, the type of processing unit 30-2 is a grinding unit. In Modification 4, the processing tool is a cutting blade. In this embodiment, where processing unit 30-2 is a grinding unit, the operating conditions of the processing tool include the rotational speed of the spindle to which the grinding wheel is fixed.
[0061] In the modified example 4, the processing data includes measurement data of the workpiece 100 during processing, such as the vibration of the grinding wheel fixed to the tip of the spindle and the holding table 10 that holds the workpiece 100, the current and voltage of the motor that drives the spindle and the holding table 10, the torque generated when the spindle and the holding table 10 move or rotate, the Z-axis load applied to the holding table 10, the grinding feed rate which is the relative movement speed of the processing unit 30-2 with respect to the holding table 10, the supply pressure, temperature and flow rate of the grinding water, and the thickness of the workpiece 100; images before and after processing captured by the imaging unit 20; information on scratches and chips on the workpiece 100, the width, position, number and size of grinding marks, surface roughness, foreign matter attached to the workpiece 100, etc., measured by image processing of the control unit 70 based on the images; and changes in the image before and after processing.
[0062] The workpiece processing methods according to Modifications 3 and 4 are all obtained by changing the processing step 1005 of the workpiece processing method according to the embodiment to a different processing, and therefore they produce the same effects and advantages as the embodiment.
[0063] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core of the present invention. In the embodiments described above and each of the modifications, the processing units 30, 30-1, and 30-2 are a cutting unit that performs cutting, a laser beam irradiation unit that performs laser processing, and a grinding unit that performs grinding, respectively. However, the present invention is not limited thereto, and may also include a plasma processing unit that irradiates plasma to process the workpiece 100, an attachment unit that attaches a protective member to the workpiece 100 and performs protective member installation processing, an ultraviolet irradiation unit equipped with an ultraviolet irradiator that irradiates ultraviolet light to the workpiece 100 and performs ultraviolet irradiation processing on the workpiece 100, a cleaning unit equipped with a nozzle that supplies cleaning liquid or cleaning gas to the workpiece 100 and performs cleaning processing on the workpiece 100, or an inspection unit that inspects the workpiece 100 (for example, inspecting for chipping, inspecting surface roughness, etc.). [Explanation of Symbols]
[0064] 1 Processing Unit 10,10-2 Holding Table 20 Imaging Unit 30, 30-1, 30-2 Processing Units 100 Work 110 Identification Mark 120 reference points 130, 130-1, 130-2 Positional relationship
Claims
1. A processing apparatus comprising a holding table for holding a workpiece, an imaging unit for imaging a workpiece held on the holding table, and a processing unit for processing a workpiece held on the holding table, wherein a workpiece on which an identification mark is displayed for identifying the workpiece is processed, A positional relationship storage step that stores the positional relationship between the reference point of the workpiece and the identification mark, A holding step of holding the workpiece in the holding table, A reference point detection step involves imaging the workpiece held on the holding table with an imaging unit and detecting the reference point, A reading step in which, based on the positional relationship recorded in the positional relationship storage step, the identification mark is detected, the identification mark is imaged with the imaging unit and the identification mark is read, Processing steps for processing the workpiece, An information recording step that records the information of the workpiece indicated by the identification mark read in the reading step, and the processing information related to the processing step, Equipped with, The reference point is one of the following: the center of the workpiece, a notch or orientation flat which is a mark indicating the crystal orientation of the workpiece and is formed only once on the outer edge of the workpiece, or a characteristic pattern which is formed only once on the workpiece. A method for processing a workpiece, characterized in that the identification mark has a size of 1 μm or more and 10 μm or less.
2. The position and size of the identification mark are determined for each lot of the workpiece. The method for processing a workpiece according to claim 1, characterized in that, after performing the positional relationship storage step for the first workpiece in a lot, the holding step, the reference point detection step, the reading step, the processing step, and the information recording step are performed for each workpiece in the same lot to be processed by the processing device.