TEST SUBSTRATE

Abstract

Verification method for checking, using a test substrate (11), whether a component of a cutting device (2) forms a scratch on an upper surface (21a) of a workpiece (21) when a cutting blade (32) cuts the workpiece (21), the test substrate (11) exhibits: an upper surface of the test substrate (11) with a groove section (17) for simulated cutting, wherein the groove section (17) has a width (17a) which the cutting blade (32) can pass through, and a color layer (15) arranged on the upper surface of the test substrate (11) to improve the visibility of a scratch formed on the upper surface, the review procedure includes: a holding step (S10) with holding a lower surface side of the test substrate (11), with the upper surface (11a) of the test substrate (11) facing upwards, by a clamping table (20) which is arranged in an application and removal area in which the test substrate (11) is applied or removed; a movement step (S20) involving the movement of the clamping table (20) from the application and removal area to a cutting area, in which a simulated cutting of the test substrate (11) is performed after the holding step (S10); a simulated cutting step (S30) comprising performing the simulated cutting by positioning a lower end of the cutting blade (32) at a predetermined height higher than a bottom (17c) of the groove section (17), and passing a portion of the cutting blade (32) through the groove section (17); and an image acquisition step (S50) involving the acquisition of an image of the upper surface of the test substrate (11).

Description

BACKGROUND OF THE INVENTION AREA OF THE INVENTION

[0001] The present invention relates to a test substrate for use in checking whether a component of a cutting device forms a scratch on the upper surface of a workpiece when a cutting blade cuts the workpiece, and to a verification method comprising checking, by using the test substrate, whether a scratch is formed on the upper surface of the workpiece or not. DESCRIPTION OF THE RELATED STATE OF THE ART

[0002] Many types of electronic equipment incorporate a component chip containing a single component, such as an integrated circuit (IC) or a large-area integration (LSI). The component chip is manufactured by dividing a wafer (workpiece)—which has multiple components embedded on its top surface—into individual components using a cutting device or similar tool. The cutting device includes a spindle equipped with a cutting blade at its distal end. Part of the spindle is rotatably mounted within a spindle housing. A blade cover, which partially conceals the cutting blade, is coupled to the spindle housing.

[0003] The blade cover is equipped with a cutting water supply nozzle for delivering cutting water to a machining point where the cutting blade and the workpiece are in contact during the cutting process (see, for example, patent application JP H11-34039A). A clamping table for holding the workpiece under suction is located beneath the spindle housing. A ball screw-type machining feeder is coupled to a lower part of the clamping table. The machining feeder moves the clamping table between (i) a loading and unloading area where the workpiece is loaded and unloaded, and (ii) a cutting area where the workpiece is cut.

[0004] A vertically movable divider plate is provided between the loading and unloading area and the cutting area to reduce the flow of cutting waste and mist generated during cutting from the cutting area to the loading and unloading area (see, for example, Publication JP 2012 - 178 511 A). The lower end of the divider plate is positioned at a height such that it does not contact the workpiece when the workpiece, held by the clamping table, moves between the loading and unloading area and the cutting area. However, during a changeover operation, the divider plate may be inadvertently positioned lower than intended.Furthermore, during a cutting blade change or an adjustment of the cutting water supply nozzle position, a distal end section of the cutting water supply nozzle may be incorrectly installed in a position lower than intended.

[0005] In such a case, the problem arises that the parting plate or the cutting water supply nozzle comes into contact with the workpiece's surface, creating a scratch (contact mark) and consequently producing a defective product. If the problem with the parting plate, cutting water supply nozzle, or similar component is not detected early, defective products will be manufactured successively. Therefore, the workpiece's external appearance after cutting can be inspected to verify whether components of the cutting device, such as the parting plate and cutting water supply nozzle, are properly installed. For example, an automatic optical inspection (AOI) device can be used to check the workpiece's surface. SUMMARY OF THE INVENTION

[0006] However, automatic optical inspection devices are very expensive, resulting in high inspection costs. Furthermore, automatic optical inspection devices inspect very narrow areas sequentially, making it time-consuming to inspect the entire upper surface of the workpiece. Conversely, if the inspection areas and positions are limited, there is a possibility of overlooking a scratch on the workpiece, preventing early detection of product defects. The present invention addresses these problems. It aims to verify, at a relatively low cost, whether components of the cutting device are properly installed, instead of using an automatic optical inspection device to inspect the workpiece.

[0007] In accordance with one aspect of the present invention, a test substrate is provided for use in the verification method described below for checking whether a component of a cutting device forms a scratch on an upper surface of a workpiece when a cutting blade cuts the workpiece, wherein the test substrate has an upper surface of the test substrate with several grid-like arranged groove sections for simulated cutting, wherein the groove sections have a width through which the cutting blade can pass, and has a color layer arranged on the upper surface of the test substrate to improve the visibility of a scratch formed on the upper surface.

[0008] Preferably, a pigment in the paint layer contains carbon, silicon dioxide or titanium dioxide.

[0009] In accordance with another aspect of the present invention, a verification method is provided by using a test substrate for verifying whether a component of a cutting device forms a scratch on an upper surface of a workpiece when a cutting blade cuts the workpiece, wherein the test substrate has an upper surface of the test substrate with a groove section for simulated cutting, the groove section having a width through which the cutting blade can pass, and a colored layer arranged on the upper surface of the test substrate to enhance the visibility of a scratch formed on the upper surface, wherein the verification method includes a holding step involving holding a lower surface of the test substrate with the upper surface of the test substrate facing upwards by a clamping table.which is located in a mounting and removal area where the test substrate is mounted or removed, comprises a movement step involving moving the clamping table from the mounting and removal area to a cutting area where, after the holding step, a simulated cutting of the test substrate is performed, a simulated cutting step involving performing the simulated cutting by positioning a lower end of the cutting blade at a predetermined height higher than the bottom of the groove section, and passing a portion of the cutting blade into the groove section, and an image acquisition step involving capturing an image of the upper surface of the test substrate.

[0010] The test substrate, according to one mode of the present invention, has a colored layer on its upper surface to enhance the visibility of a scratch formed on the upper surface of the test substrate. When the clamping table, which holds the lower surface of the test substrate under suction, is moved from the application and removal area to the cutting area, for example, when the lower end of the separating plate is in contact with the upper surface of the test substrate, the colored layer is removed in a contact area. Furthermore, according to one mode of the present invention, the test substrate has a groove section for simulated cutting on its upper surface, the groove section having a width through which the cutting blade can pass.In a case where the cutting blade and the clamping table, which holds the lower surface of the test substrate under suction, are moved relative to each other, so that part of the cutting blade passes through the groove section, for example when the distal end section of the cutting water supply nozzle is in contact with the upper surface of the test substrate, the paint layer is peeled off in a contact area.

[0011] The presence or absence of paint peeling can be detected using an imaging unit, which is generally part of the cutting device. Therefore, compared to a case where the workpiece is inspected by an automatic optical inspection device, it is possible at a relatively low cost to verify whether components, such as the parting plate and the cutting water supply nozzle, are properly installed. Furthermore, if paint peeling does not occur, the same test substrate can be reused. Consequently, inspection costs can be reduced by reusing the test substrate.

[0012] The above and other tasks, features and advantages of the present invention and the manner of its implementation will become clearer by studying the following description and the attached claims, with reference to the attached drawings which show a preferred embodiment of the invention, and the invention itself will be best understood by this. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of a test substrate; Fig. Figure 2 is an enlarged cross-sectional view of a portion of the test substrate; Fig. Figure 3 is a perspective view of a cutting device; Fig. Figure 4 is a perspective exploded view of a cutting unit; Fig. Figure 5 is a view illustrating a partition plate and similar items; Fig. 6 is a flowchart illustrating a verification procedure; Fig. 7A is an image illustrating the entire test substrate; Fig. 7B is an enlarged image of part of a top surface where a scratch has formed; Fig. 8A is an image illustrating the entire test substrate; and Fig. 8B is an enlarged image of part of a top surface where a scratch has formed. DETAILED EXPLANATION OF THE PREFERRED FORM OF EXECUTION

[0013] An embodiment in accordance with a mode of the present invention will now be described with reference to the accompanying drawings. First, a test substrate 11 will be described. Fig. Figure 1 is a perspective view of the test substrate 11 in accordance with a preferred embodiment. Fig. Figure 2 is an enlarged sectional view of a part of the test substrate 11. The test substrate 11 is used to check whether components of a cutting device 2 form a scratch (contact mark) on a top surface 21a of a workpiece 21 when a cutting blade 32 cuts the workpiece 21 (see Figure 2). Fig. 3).

[0014] The test substrate 11 has essentially the same diameter as the workpiece 21. However, since the test substrate 11 is not assumed to be cut by the cutting blade 32, its thickness differs from a thickness corresponding to the diameter of a silicon wafer as defined in a standard of Semiconductor Equipment Materials International (SEMI) or similar. For example, the test substrate 11 in accordance with the present embodiment includes a disk-shaped wafer 13 made of a resin, having a diameter of approximately 300 mm and a thickness of approximately 2 mm. The resin used is polycarbonate, polyethylene terephthalate, or a similar material.

[0015] If the wafer 13 is formed from a resin, it can be manufactured cost-effectively compared to a case where the wafer 13 is formed from silicon. It should be noted that the material of the wafer 13 is not necessarily limited to resin. The wafer 13 can be formed from a semiconductor, such as silicon or another material. A color layer 15 is provided on the side of the entire upper surface 13a of the wafer 13 (the side of the upper surface 11a of the test substrate 11). In the present embodiment, the uppermost surface of the color layer 15 is configured as the upper surface 11a of the test substrate 11. Furthermore, a lower surface 11b of the test substrate 11 corresponds to the lower surface of the wafer 13.

[0016] The thickness of the color layer 15 is, for example, 10 µm to several tens of µm and is sufficiently smaller than a width 17a or a depth 17b of a groove section 17 described later. The color layer 15 is applied to the side of the entire upper surface 11a, including the side sections and a lower section of the groove section 17. The color layer 15 contains, for example, a pigment that includes carbon, such as carbon black or a carbon nanotube. The color layer 15, which exhibits a substantially uniform black color, is formed by coating the side of the upper surface 13a of the wafer 13, on which several groove sections 17 are formed, with a paint in which the black carbon is dispersed in an organic solvent, and then allowing the paint to dry.

[0017] The color layer 15 is used to improve the visibility of a scratch that forms on the top surface 11a of the test substrate 11. For example, if a scratch forms on the side of the top surface 11a, the color layer 15 is peeled away in an area corresponding to the scratch, and the top surface 13a of the wafer 13 is exposed. The color of the wafer 13 differs from the color of the color layer 15. For example, if an imaging unit 24a (see Fig. 3), which is usually included in the cutting device 2, captures an image of the side of the upper surface 11a, so the peeling of the ink layer 15 can be detected without using an automatic, high-performance optical inspection device.

[0018] The pigment forming color layer 15 is not limited to carbon but can include silica (silicon oxide). A pigment containing silica is formed, for example, by a silica powder or slurry produced from chips generated during the cutting, grinding, or similar processes of a silicon wafer. In addition to silica, the slurry contains silicon dioxide doped with Bohr (B), phosphorus (P), or similar elements, a silicon metal oxide, or similar compounds. In a case where a pigment belonging to this slurry is used, color layer 15 exhibits a substantially uniform gray color.

[0019] Furthermore, the pigment forming the color layer 15 can contain titanium dioxide (titanium oxide) or calcium carbonate. In a case where a pigment containing titanium oxide or calcium carbonate is used, the color layer 15 exhibits a substantially uniform white color. An underlayer (not illustrated) can also be provided between the wafer 13 and the color layer 15 to control the adhesion of the color layer 15 to the wafer 13. If, for example, a silicone resin, a fluorocarbon resin, or the like is formed as the underlayer, the adhesion of the color layer 15 is reduced, and consequently, the color layer 15 is easily peeled off (i.e., the visibility of a scratch is enhanced).

[0020] A predetermined structure (not illustrated) used to detect the positions of the groove sections 17, the orientation of the wafer 13, or similar features, is formed on the upper surface 13a of the wafer 13. This predetermined structure is referred to as a key feature, an alignment marker, or similar. The predetermined structure is recessed into the upper surface 13a to a predetermined depth or protrudes from the upper surface 13a by a predetermined height. Consequently, even if the ink layer 15 is present on the upper surface 13a, the imaging unit 24a, typically included in the cutting device 2, can identify the predetermined structure.

[0021] Several groove sections 17 are arranged in a grid pattern on the side of the upper surface 13a of the wafer 13. During the simulated cutting process described later, the cutting blade 32 passes through each of the groove sections 17. The distance between two adjacent groove sections 17 is, for example, a predetermined value of 10 mm or more and 20 mm or less. Therefore, if the distance between the groove sections 17 is set relatively large, the time required for the simulated cutting process can be reduced, enabling efficient simulated cutting. The groove sections 17 have a width 17a with sufficient dimensions for the cutting blade 32, which typically has a blade thickness of approximately 100 µm, to be able to pass through the groove sections 17 (see Figure 1). Fig. 2) The width 17a is a length in a direction perpendicular to the longitudinal direction of the groove section 17 on the upper surface 11a. The width 17a is, for example, 5 mm.

[0022] If the width 17a of the groove section 17 is set relatively large, contact between the cutting blade 32 and the inner side surfaces of the groove section 17 during simulated cutting can be avoided relatively easily compared to a case where the width 17a equals the thickness of the cutting blade 32. The depth 17b of the groove section 17 is the length from the upper surface 11a to a bottom 17c of the groove section 17 and is equal to or greater than a maximum amount of the blade projection of the cutting blade 32. For example, the depth 17b is 1.5 mm. If the depth 17b is set relatively large, cutting the bottom 17c of the groove section 17 during simulated cutting can be avoided relatively easily compared to a case where the depth 17b is less than the amount of the blade projection of the cutting blade 32.

[0023] The cutting device 2, in which the test substrate 11 is used, is described next. Fig. Figure 3 is a perspective view of the cutting device 2. Furthermore, it illustrates... Fig. 3. A portion of the components of the cutting device 2 constitutes a functional block. Furthermore, the following are directions perpendicular to each other: the X-axis direction (a processing feed direction), the Y-axis direction (a positioning direction), and the Z-axis direction (a height direction, an up-down direction, or a cutting feed direction). The front surface of the cutting device 2 is equipped with an operating panel 4. An operator can, for example, set processing conditions or similar parameters for the cutting device 2 by executing a predefined input via the operating panel 4. A side surface on the front of the cutting device 2 is equipped with a monitor (display device) 6.

[0024] Monitor 6 displays a guide to the operator during operation, an image captured by the imaging unit 24a (described later), or similar information. Alternatively, monitor 6 can be a touch panel that also serves as the control panel 4. In this case, the control panel 4 is omitted. The cutting device 2 generally cuts the workpiece 21. Several planned parting lines (paths), not shown, are arranged in a grid pattern on the upper surface 21a of the workpiece 21. A component, not shown, such as an integrated circuit (IC) or a large-area integration (LSI), is formed in each of the areas delimited by the multiple planned parting lines.

[0025] A circular dicing band 23, formed from a resin, is formed on the side of a lower surface 21b of the workpiece 21. The diameter of the dicing band 23 is larger than the diameter of the workpiece 21. The workpiece 21 is attached to a central section of the dicing band 23, and a surface of an annular frame 25, formed from a metal, is attached to an outer circumferential section of the dicing band 23. The workpiece 21 is held in a cassette 8 in the form of a frame unit 27, in which the workpiece 21 is supported by the frame 25 via the dicing band 23. When the test substrate 11 is to be inserted into the cutting device 2, the test substrate 11 is held in the cassette 8 in the form of a frame unit (not illustrated), in which the test substrate 11 is supported by the frame 25 via the dicing band 23.

[0026] The cassette 8 is arranged on a cassette table 10. A cassette lift 12, which moves the cassette table 10 up and down, is coupled to a lower part of the cassette table 10. A push-pull arm 14 is provided at the rear of the cassette table 10. The push-pull arm 14 unloads the workpiece 21 or the test substrate 11, in the form of a frame unit, from the cassette 8 and loads the workpiece 21 or the test substrate 11, in the form of a frame unit, into the cassette 8. A pair of positioning elements (guide rails) 16, which adjust the position of the frame unit in the X-axis direction, are provided on both sides of a movement path of the push-pull arm 14.

[0027] A first transport unit 18, which transports the frame unit away from the pair of positioning elements 16, is located in the vicinity of the pair of positioning elements 16. The first transport unit 18 has an arm, a pivoting mechanism located at one end of the arm, and a suction mechanism located at the other end of the arm. The suction mechanism includes, for example, a vacuum pad that draws the frame 25 into position. The first transport unit 18 transports the frame unit by rotating the arm through a predetermined angle using the pivoting mechanism in a state where the frame 25 is drawn into position by the suction mechanism.

[0028] The first transport unit 18 transports the frame unit to a clamping table 20, which is located in an installation and removal area R. AThe clamping table 20 is arranged in the X-axis direction in the vicinity of the cassette table 10. A disc-shaped porous plate is attached to the side of the upper surface of the clamping table 20. One end of a flow passage (not illustrated) formed in the clamping table 20 is connected to the side of the lower surface of the porous plate. A suction source (not illustrated), such as an ejector, is connected to the other end of the flow passage. By actuating the suction source, a vacuum can be transferred to the upper surface of the porous plate. Consequently, the upper surface of the clamping table 20 serves as a holding surface 20a, which holds the frame unit under suction.

[0029] Furthermore, several clamping units 20b are provided for attaching the frame 25 to an outer circumferential section of the clamping table 20. A θ-table (not illustrated), which rotates the clamping table 20 about a predetermined axis of rotation, is coupled to a lower part of the clamping table 20. A ball screw-type machining feeder unit (not illustrated) is coupled to another lower part of the θ-table.

[0030] The machining feeder unit moves the clamping table 20 together with the θ-table along the X-axis direction. In particular, the clamping table 20 moves between the mounting and removal areas R. A , in which the workpiece 21 or the test substrate 11 is attached to or removed from the holding surface 20a, and a cutting area R B, in which the workpiece 21 is actually cut or the test substrate 11 is cut in a simulated manner. A right-angled cover element 22a is provided between the θ-table and the clamping table 20. Bellows 22b, which are capable of expanding and contracting in the X-axis direction, are arranged on both sides of the cover element 22a in the X-axis direction. A support element 24 is arranged above the clamping table 20.

[0031] The imaging unit 24a is positioned relative to the support element 24 such that it is able to face the holding surface 20a. The imaging unit 24a is, for example, an optical microscope camera comprising a predetermined optical system and an imaging element, such as a charge-coupled device image sensor (CCD image sensor) or a complementary metal-oxide semiconductor image sensor (CMOS image sensor). The imaging unit 24a acquires an image by capturing the side of the upper surface 21a of the workpiece 21 or the side of the upper surface 11a of the test substrate 11. The image acquired by the imaging unit 24a is stored in a memory device belonging to the cutting device 2 and is also displayed on the monitor.

[0032] The imaging unit 24a is a component of the cutting device 2, and this component is generally aligned with the cutting device 2. A cutting unit 26 is provided on one side of the imaging unit 24a in the X-axis direction. A ball screw-type cutting feeder unit (not illustrated) for moving the cutting unit 26 along the Z-axis direction is coupled to the cutting unit 26. A ball screw-type positioning unit for moving the cutting feeder unit along the Y-axis direction is also coupled to the cutting feeder unit.

[0033] The cutting unit 26 is described below with reference to Fig. 4 described. Fig. Figure 4 is a perspective exploded view of the cutting unit 26. The cutting unit 26 has a cylindrical spindle housing 28. A portion of a cylindrical spindle 30 is rotatably mounted in the spindle housing 28. A rotary drive source (not illustrated), such as a motor, is provided at one end section of the spindle 30. The cutting blade 32 is attached to another end section of the spindle 30.

[0034] The cutting blade 32, for example, is a hub blade with a disc-shaped hub base made of aluminum. An annular cutting edge 32a, in which abrasive grains made of diamond or similar material are fixed in a state where they are distributed in an electroformed bond, is attached to the side surface of the hub base. A blade cover 34 is attached to the spindle housing 28 to cover an upper part of the cutting blade 32. A cutting water supply nozzle 36 is attached to the blade cover 34 such that it is adjacent to a side surface of the cutting blade 32.

[0035] Cutting water is, for example, pure water. The cutting water is supplied to the cutting water supply nozzle 36 through a tube 38, which is provided at an upper section of the blade cover 34. A removable cover 44 is attached to a side section of the blade cover 34. The removable cover 44 has a cutting water supply nozzle 46. The cutting water supply nozzle 46 is arranged such that it is adjacent to another side surface of the cutting blade 32 when the removable cover 44 is attached to the side section of the blade cover 34.

[0036] The cutting water is supplied to the cutting water supply nozzle 46 through a tube 48, which is located at an upper section of the removable cover 44. An optical blade damage detection unit 50 is attached to an upper section of the blade cover 34. When changing the cutting blade 32, the removable cover 44 is first removed from the blade cover 34, and then the cutting blade 32 is removed from the spindle 30. After a new cutting blade 32 has been attached to the spindle 30, the removable cover 44 is then attached to the blade cover 34.

[0037] Furthermore, during the adjustment process of the cutting water supply nozzles 36 and 46, the positions are adjusted by setting the mounting positions of the blade cover 34 and the removable cover 44 such that longitudinal sections of the cutting water supply nozzles 36 and 46 between them accommodate the cutting blade 32 and are essentially parallel to the X-axis direction. Next, with reference to Fig. 5 a description of a separating plate 52, which is located at a boundary between the application and removal area R A and the cutting area R B is arranged, and similarly implemented. A metallic housing 54 is arranged above the clamping table 20. A door unit 56, which is made of a transparent resin and is able to be opened and closed by rotating in a horizontal plane, is located on the front surface of the housing 54 (side of the monitor 6 of the in Fig. 3 illustrated cutting device 2) in the attachment and removal area R A Furthermore, a door unit 58, which is made of a transparent resin and is capable of being opened and closed by sliding in the X-axis direction, is provided on the front surface of the housing 54 in the cutting area R. B planned.

[0038] A partition wall 60 is located between the installation and removal area R A and the cutting area R B An opening section 60a is formed in a lower section of the partition wall 60. The partition plate 52 is located on the side of the mounting and removal area R. A arranged in partition wall 60. Fig. Figure 5 is a view illustrating the partition plate 52 and similar components. An upper section of the partition plate 52 is curved in the X-axis direction. This curved section is supported by a piston rod of a pneumatic cylinder 62. The pneumatic cylinder 62 itself is supported by a support element 64 attached to the housing 54. When the piston rod of the pneumatic cylinder 62 is lifted, the opening section 60a, as shown in Figure 5, is opened. Fig. Figure 5 illustrates the opening. When the piston rod is lowered, the opening section 60a closes. For example, the opening section 60a opens when the clamping table 20 is between the mounting and removal areas R. A and the cutting area R B is moved. When the workpiece 21 is cut, the opening section 60a is closed after the clamping table 20 moves to the cutting area R. B has been moved.

[0039] To the Fig. Returning to section 3, other components of the cutting device 2 are now described. The cutting device 2 includes a second transport unit 66, which unloads the workpiece 21 or similar item from the clamping table 20 after cutting, which is located in the mounting and unmounting section R. A The second transport unit 66 has an arm that is movable in the Y-axis direction. A suction mechanism for gripping the frame 25 is provided at a distal end section of the arm. A cleaning unit 68 is located at the rear near the attachment and removal area R. A The cleaning unit 68 includes a centrifugal table (not illustrated) which holds the workpiece 21 or similar under suction, and a cleaning nozzle (not illustrated) which is arranged above the centrifugal table.

[0040] The workpiece 21, which has been transported to the cleaning unit 68 by the second transport unit 66, is cleaned and then loaded into the cassette 8 by the first transport unit 18, the pair of positioning elements 16, and the push-pull arm 14. A control unit 70 controls the actuation of the cassette lift 12, the push-pull arm 14, the pair of positioning elements 16, the first transport unit 18, the clamping table 18, the imaging unit 24a, the cutting unit 26, the pneumatic cylinder 62, the second transport unit 66, the machining feeder unit, the cutting feeder unit, the positioning unit, and similar components described above.

[0041] The control unit 70 is, for example, a computer comprising a processor (processing unit) in the form of a central processing unit (CPU), a main memory device such as dynamic random access memory (DRAM), static random access memory (SRAM), or read-only memory (ROM), and an auxiliary memory device such as flash memory, a hard disk drive, or a solid-state drive. The auxiliary memory device stores software, including a predefined program. Functions of the control unit 70 are implemented by actuating the processing unit or similar means in accordance with the software. The control unit 70 moves the opening section 60a into an open state when the workpiece 21, held by the clamping table 20, is positioned between the loading and unloading areas R. A and the cutting area R B moved (see Fig. 5).

[0042] However, during a changeover of the cutting plate 52 or similar component, the cutting plate 52 may be incorrectly positioned lower than specified. Furthermore, during a changeover of the cutting blade 32 and an adjustment of the cutting water supply nozzles 36 and 46, distal end sections of the cutting water supply nozzles 36 and 46 may also be incorrectly positioned lower than specified. Accordingly, the test substrate 11 is used to verify whether components of the cutting device 2, such as the cutting plate 52 and the cutting water supply nozzles 36 and 46, are correctly positioned. Fig. Figure 6 is a flowchart illustrating a verification procedure using test substrate 11.

[0043] First, the clamping table 20, which is located in the mounting and removal area R, is held. AThe side of the lower surface 11b of the test substrate 11 is arranged in the form of a frame unit under suction (holding step S10). At this point, the upper surface 11a of the test substrate 11 is facing upwards, and the paint layer 15 is thus exposed upwards. After holding step S10, the opening section 60a is moved into an open position, and then the clamping table 20 is moved from the mounting and removal area R. A to the cutting area R B moved (movement step S20). If the separating plate 52 is attached at a position lower than the specified position, a scratch will be formed on the side of the upper surface 11a of the test substrate 11, and the paint layer 15 will be peeled off in an area corresponding to the scratch.

[0044] After movement step S20, the orientation of the clamping table 20 is adjusted by the θ-table using the positions of the two key structures, which are separated from each other in a diagram of the side of the upper surface 11a or similar, such that the longitudinal direction of the groove sections 17 is essentially parallel to the X-axis direction. Then, the cutting blade 32, which is rotated at high speed, is positioned in the extension of a groove section 17, and furthermore, a lower end of the cutting blade 32 is positioned at a predetermined height that is higher than the bottom 17c in the groove section 17. In this state, the clamping table 20 is moved in the X-axis direction relative to the cutting blade 32 without cutting water being supplied from the cutting water supply nozzles 36 and 46.

[0045] The simulated cutting of the test substrate 11 is therefore performed by having a portion of the cutting blade 32 pass through the groove section 17 (simulated cutting step S30). After the simulated cutting has been performed from one end to the other of one groove section 17, the cutting unit 26 is adjusted by a predetermined amount. The simulated cutting is then performed in a similar manner after the lower end of the cutting blade 32 has been positioned in the extension of another groove section 17 that is adjacent in the Y-axis direction to the one groove section 17 in which the simulated cutting was performed. After the simulated cutting has been performed in all groove sections 17 that are parallel in one direction, the clamping table 20 is rotated by 90°.

[0046] The simulated cutting is then performed in a similar manner in all remaining groove sections 17. If distal end sections of the cutting water supply nozzles 36 and 46 are in contact with the side of the upper surface 11a, for example, scratches are formed on the side of the upper surface 11a during the simulated cutting step S30, and the paint layer 15 is peeled off in areas corresponding to the scratches. After the simulated cutting step S30, the clamping table 20 is removed from the cutting area R. B to the installation and removal area R A moved, and the second transport unit 66 moves the test substrate 11 from the clamping table 20 to the cleaning unit 68.

[0047] The centrifugal table (not illustrated) is then rotated for a predetermined period without the cleaning water or similar substance being ejected from the cleaning nozzle, in a state where the centrifugal table holds the side of the lower surface 11b of the test substrate 11 by suction (simulated cleaning step S40). If a component of the cleaning unit 68 is in contact with the side of the upper surface 11a, a scratch will also form on the side of the upper surface 11a during simulated cleaning step S40, and the paint layer 15 will be peeled off in an area corresponding to the scratch.

[0048] After the simulated cleaning step S40, the test substrate 11 is loaded into the cassette 8 using the first transport unit 18, the pair of positioning elements 16, the push-pull arm 14, and similar components. Following this sequence of operations, the test substrate loaded into the cassette 8 is removed from the cassette 8. The clamping table 20 then holds the test substrate 11 under suction such that the upper surface 11a is facing upwards. In this state, an image of the upper surface 11a of the test substrate 11 is captured (image acquisition step S50). The resulting image is stored in the auxiliary memory of the control unit 70.

[0049] Fig. Figure 7A is an image illustrating the entire test substrate 11 in which the color layer 15 including the black carbon as pigment is formed on the side of the upper surface 11a. Fig. Figure 7B is an enlarged image of part of the side of the upper surface 11a where a scratch has formed. Furthermore, Fig. 8A is an image illustrating the entire test substrate 11 in which the color layer 15 including the titanium oxide as pigment is formed on the side of the upper surface 11a. Fig. 8B is an enlarged image of part of the side of the upper surface 11a where a scratch has formed.

[0050] The acquired image is processed by predefined image processing software installed on the control unit 70, and a scratch and peeling of the paint layer 15 are detected. A detection process uses, for example, information regarding the brightness or hue of each of several pixels that make up the image. Specifically, the image processing software calculates a difference in brightness (contrast) between a pixel and a multitude of pixels surrounding that pixel. If the calculated contrast is higher than a predefined value, the image processing software determines that a scratch is present in the pixel area.

[0051] In the present embodiment, a scratch on the test substrate 11 and peeling of the paint layer 15 can be detected by the imaging unit 24a. Compared to a case in which the workpiece 21 is inspected by an automatic optical inspection device, it is therefore possible to check at relatively low cost whether components, such as the cutting water supply nozzles 36 and 46 and the parting plate 52, are correctly attached or not. If peeling of the paint layer 15 does not occur, the same test substrate 11 can also be reused, thus reducing inspection costs.

[0052] Furthermore, the image processing software can determine for each of a multitude of pixels whether a scratch is present or not by calculating an average brightness value for several pixels (for example, 10 pixels) within a predetermined area and comparing average brightness values ​​between adjacent areas of the predetermined size. This can improve processing speed compared to calculating contrast for each pixel. Moreover, structures, methods, and the like can be suitably modified and implemented in accordance with the preceding embodiment without departing from the scope of the present invention. For example, the inspection described above can be performed using a frame unit (not illustrated) in which a rectangular test substrate 11 is supported by the frame 25 via the dicing band 23.

[0053] In particular, a test substrate 11 can be used in which a color layer 15 containing silica or sludge as a pigment is formed on a wafer 13 that is 200 mm square and 2 mm thick and made of polyethylene terephthalate. The use of silica or sludge as a pigment has the advantage that, even if the color layer 15 adheres to the inside of the cutting device 2, a problem such as contamination is less likely to occur compared to a case where a different material adheres.

[0054] Furthermore, the image acquisition step S50 does not necessarily have to be performed last, but can be executed according to a given schedule before and after the movement step S20, before and after the simulated cutting step S30, and before and after the simulated cleaning step S40. For example, by comparing images of the side of the upper surface 11a before and after the movement step S20, excluding the effect of the cutting water supply nozzles 36 and 46, it is possible to check whether the parting plate 52 is correctly positioned or not. Similarly, by comparing images before and after the simulated cutting step S30, it is possible to check whether the cutting water supply nozzles 36 and 46 are correctly positioned or not, excluding the effect of the parting plate 52.

[0055] The image comparison does not necessarily have to be performed using image processing software. For example, the captured images can be displayed on monitor 6, and the operator can check the images for scratches and peeling of the ink layer 15. Regarding the test substrate 11, the preceding description was carried out using an example where the ink layer 15 is formed on the wafer 13, which has the multiple groove sections 17 formed on it. However, the multiple groove sections 17 can be formed by cutting the side of the upper surface 13a of the wafer 13 with the ink layer 15 formed on the upper surface 13a. In this case, the ink layer 15 does not remain on the side surfaces and bottoms 17c of the groove sections 17. However, there is a problem with the inspection described above during execution.

[0056] The present invention is not limited to the details of the preferred embodiment described above. The scope of protection of the invention is defined by the attached claims, and all modifications and adaptations that fall within the equivalent scope of protection of the claims are therefore included in the invention.

Claims

[1] Verification method for checking, using a test substrate (11), whether a component of a cutting device (2) forms a scratch on an upper surface (21a) of a workpiece (21) when a cutting blade (32) cuts the workpiece (21), the test substrate (11) exhibits: an upper surface of the test substrate (11) with a groove section (17) for simulated cutting, wherein the groove section (17) has a width (17a) which the cutting blade (32) can pass through, and a color layer (15) arranged on the upper surface of the test substrate (11) to improve the visibility of a scratch formed on the upper surface, the review procedure includes: a holding step (S10) with holding a lower surface side of the test substrate (11), with the upper surface (11a) of the test substrate (11) facing upwards, by a clamping table (20) which is arranged in an application and removal area in which the test substrate (11) is applied or removed; a movement step (S20) involving the movement of the clamping table (20) from the application and removal area to a cutting area, in which a simulated cutting of the test substrate (11) is performed after the holding step (S10); a simulated cutting step (S30) comprising performing the simulated cutting by positioning a lower end of the cutting blade (32) at a predetermined height higher than a bottom (17c) of the groove section (17), and passing a portion of the cutting blade (32) through the groove section (17); and an image acquisition step (S50) involving the acquisition of an image of the upper surface of the test substrate (11). [2] Test substrate (11) for use in the verification method according to claim 1 for verifying whether a component of a cutting device (2) forms a scratch on an upper surface (21a) of a workpiece (21) or not when a cutting blade (32) cuts the workpiece (21), wherein the test substrate (11) comprises: an upper surface of the test substrate (11) with several grid-like arranged groove sections (17) for simulated cutting, wherein the groove sections (17) have a width (17a) which the cutting blade (32) can pass through; and a color layer (15) arranged on the upper surface of the test substrate (11) to improve the visibility of a scratch formed on the upper surface. [3] Test substrate (11) according to claim 2, wherein a pigment of the color layer comprises carbon, silicon dioxide or titanium oxide.

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