Processing device and processing method

Abstract

To make it possible to grasp the chip fly during processing.SOLUTION: A processing device 1 is a processing device that processes a workpiece with a starting point for division formed along a plurality of intersecting planned division lines and divides the workpiece into a plurality of chips along the planned division lines. The processing device includes: a holding table 20 for holding the workpiece; grinding units 30, 40 with grinding wheels 31, 41 for grinding the workpiece held by the holding table 20; and a thickness gauge 70 which is a detection unit for detecting the chip fly of the workpiece.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a processing apparatus and a processing method for processing a workpiece having division starting points formed thereon and dividing the workpiece into a plurality of chips. [Background technology]

[0002] For example, in the manufacturing process of semiconductor device chips, a process known as Stealth Dicing Before Grinding (SDBG) is widely used in which a semiconductor device wafer is irradiated with a laser beam to form a modified layer along the intended division line inside, and then the back surface is ground to divide it into individual chips.

[0003] In order to increase the flexural strength of the chips, the rear surface of the divided wafer is polished, and a processing device that performs grinding and polishing in succession has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-153090 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a wafer on which a modified layer has been formed is ground and polished by the processing apparatus shown in Patent Document 1 or the like, chips may fly off.

[0006] When chip flying occurs, there is a risk that the chip may damage the wafer, so improvements are eagerly desired. However, because the measures to be taken may differ depending on the timing at which the chip flying occurs, there is a demand for knowing the timing at which the chip flying occurs.

[0007] An object of the present invention is to provide a processing device and a processing method that are capable of detecting chip flying during processing. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the processing apparatus of the present invention is a processing apparatus that processes a workpiece having division starting points formed along a plurality of intersecting planned division lines and divides it into a plurality of chips along the planned division lines, and is characterized in that it comprises a holding table that holds the workpiece, a grinding unit having a grinding wheel that grinds the workpiece held by the holding table, and a detection unit that detects chip flying of the workpiece.

[0009] In the processing apparatus, the detection unit may detect the chip flying by detecting the height position of the upper surface of the workpiece held by the holding table.

[0010] In the processing apparatus, the detection unit may include an image sensor, form an image of the workpiece held by the holding table, and detect the chip flying based on the image.

[0011] In the above-mentioned processing apparatus, the processing apparatus may include a processing chamber that houses the grinding unit, and a holding table moving mechanism that can freely position the holding table inside and outside the processing chamber, and the processing chamber may be formed with an entrance / exit that allows the holding table to enter and exit, and the detection unit may be disposed inside the processing chamber.

[0012] In the above-mentioned processing apparatus, the processing apparatus includes a processing chamber that houses the grinding unit, and a holding table moving mechanism that can freely position the holding table inside and outside the processing chamber, and the processing chamber is formed with an entrance / exit that allows the holding table to enter and exit, and the detection unit may be disposed above the entrance / exit.

[0013] The processing method of the present invention is a processing method for dividing a workpiece having division starting points formed along a plurality of intersecting planned division lines into a plurality of chips along the planned division lines, and is characterized by comprising a holding step of holding the workpiece on a holding table, a grinding step of grinding the workpiece held on the holding table with a grinding wheel to divide the workpiece into a plurality of chips from the division starting points, and a confirmation step of checking whether or not the workpiece has chipped using a detection unit that detects chipping of the workpiece.

[0014] In the above processing method, the checking step may include detecting a height position of an upper surface of the workpiece held by the holding table.

[0015] In the above machining method, the checking step may include forming an image of the workpiece held on the holding table by an imaging element, and checking for the presence or absence of flying chips based on the image.

[0016] In the above processing method, the confirmation step may be performed after the grinding step is performed.

[0017] In the above processing method, the checking step may be performed during the grinding step. Effect of the Invention

[0018] The present invention has an effect of making it possible to grasp chip flying during machining. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view illustrating a configuration example of a processing device according to the first embodiment. [Diagram 2] FIG. 2 is a perspective view showing an example of a workpiece to be processed by the processing apparatus shown in FIG. [Diagram 3] FIG. 3 is a plan view seen from the rear surface side of the workpiece divided into individual chips by the processing apparatus shown in FIG. [Figure 4]FIG. 4 is a side view showing in cross section a processing chamber of the processing apparatus shown in FIG. [Diagram 5] FIG. 5 is a perspective view illustrating a schematic configuration example of a polishing unit of the processing apparatus illustrated in FIG. [Figure 6] FIG. 6 is a flowchart showing the flow of the processing method according to the first embodiment. [Figure 7] FIG. 7 is a perspective view showing a surface protection step in the processing method shown in FIG. [Figure 8] FIG. 8 is a side view, partly in section, showing the division start point forming step of the processing method shown in FIG. [Figure 9] FIG. 9 is a perspective view showing an example of a workpiece on which a modified layer serving as a division starting point is formed by the division starting point forming step of the processing method shown in FIG. [Figure 10] FIG. 10 is a side view, partially in section, typically showing the holding step of the processing method shown in FIG. [Figure 11] FIG. 11 is a side view, partially in section, typically showing the grinding step of the processing method shown in FIG. [Figure 12] FIG. 12 is a plan view diagrammatically showing a confirmation step of the processing method shown in FIG. [Figure 13] FIG. 13 is a perspective view that illustrates a configuration example of a processing device according to the second embodiment. [Figure 14] FIG. 14 is a flowchart showing the flow of the processing method according to the second embodiment. [Figure 15] FIG. 15 is a side view, partially in section, typically showing the grinding step and the checking step of the processing method shown in FIG. [Figure 16] FIG. 16 is a side view, partially in section, typically showing another example of the grinding step and the checking step shown in FIG. [Figure 17] FIG. 17 is a side view, partially in section, that typically illustrates a checking step of the processing device according to the third embodiment. [Figure 18] FIG. 18 is a side view showing a cross section of a processing chamber of a processing device according to the fourth embodiment. [Figure 19] FIG. 19 is a side view, partially in section, that typically illustrates a confirmation step of the processing method according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The form (embodiment) 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 embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0021] [Embodiment 1] A processing apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a typical configuration example of the processing apparatus according to the first embodiment. FIG. 2 is a perspective view showing an example of a workpiece to be processed by the processing apparatus shown in FIG. 1. FIG. 3 is a plan view seen from the back side of a workpiece divided into individual chips by the processing apparatus shown in FIG. 1. FIG. 4 is a side view showing a cross section of a processing chamber of the processing apparatus shown in FIG. 1. FIG. 5 is a perspective view showing a typical configuration example of a polishing unit of the processing apparatus shown in FIG. 1.

[0022] (Workpiece) The processing apparatus 1 shown in FIG. 1 according to the first embodiment is an apparatus for dividing a workpiece 200 shown in FIG. 2 into individual device chips 210 (shown in FIG. 3). The workpiece 200 to be processed by the processing apparatus 1 shown in FIG. 1 according to the first embodiment is a wafer such as a disk-shaped semiconductor wafer or an optical device wafer, with a substrate 201 made of, for example, silicon, sapphire, SiC, or the like. As shown in FIG. 2, the workpiece 200 has a plurality of planned division lines 203 that intersect with each other set on a surface 202, and devices 204 are formed in areas partitioned by the planned division lines 203. Note that in the present invention, the substrate 201 of the workpiece 200 may be made of a material other than silicon, sapphire, or SiC, and the device 204 may not be formed.

[0023] The device 204 is, for example, an integrated circuit such as an IC (Integrated Circuit) or an LSI (Large Scale Integration), an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), an optical element such as an LED (Light-Emitting Diode), or a memory (semiconductor memory device).

[0024] 3, the workpiece 200 is divided into individual device chips 210 along the planned dividing lines 203. Each device chip 210 includes a part of the substrate 201 and a device 204 formed on a surface 202 of the substrate 201. When the workpiece 200 is divided along the planned dividing lines 203, scraps 211 consisting only of the substrate 201 are formed at the outer edge. In this specification, the device chips 210 and the scraps 211 are collectively referred to as chips 212.

[0025] (Processing equipment) 1 is an apparatus that grinds and polishes a back surface 205 behind a front surface 202 of a workpiece 200, and divides the workpiece 200 into a plurality of chips 212 along a planned division line 203. In the first embodiment, the processing apparatus 1 is a grinding and polishing apparatus that grinds and polishes the back surface 205 of the workpiece 200.

[0026] As shown in FIG. 1, the processing apparatus 1 includes an apparatus base 2, a turntable 10, for example, four holding tables 20 installed on the turntable 10, a rough grinding unit 30, a finish grinding unit 40, a polishing unit 50, a cassette mounting table 3, an alignment unit 4, a cleaning unit 5, a transport unit 80, and a control unit 100.

[0027] The turntable 10 is a disk-shaped table provided on the upper surface of the device base 2, and is provided rotatably around an axis parallel to the Z-axis direction in a horizontal plane, and is rotationally driven at a predetermined timing. The Z-axis direction is parallel to the vertical direction. On the turntable 10, for example, four holding tables 20 are arranged at equal intervals, for example, at a phase angle of 90 degrees. That is, the turntable 10 has a plurality of holding tables 20 arranged at equal angles (90 degrees in the first embodiment) in the circumferential direction.

[0028] 4, the turntable 10 includes a table body 11 that is rotatable about an axis parallel to the Z-axis direction by a driving source such as a motor, and a turntable cover 12 that covers the upper surface of the table body 11 and rotates about the axis integrally with the table body 11. A holding table 20 is disposed on the upper surface of the table body 11. The turntable cover 12 covers the upper side of the table body 11, exposing a holding surface 21 that holds the workpiece 200 of the holding table 20.

[0029] The four holding tables 20 have upper surfaces made of a porous material such as porous ceramics, and serve as holding surfaces 21 on which the workpiece 200 is placed. The holding surfaces 21 of the holding tables 20 are connected to a suction source (not shown), and the holding surfaces 21 are sucked by the suction source, thereby suctioning and holding the workpiece 200 placed on the holding surfaces 21 to the holding surfaces 21.

[0030] During processing, the holding table 20 is rotated around an axis parallel to the Z-axis direction by a rotation mechanism. The holding table 20 is moved sequentially to a carry-in / out position 301, a rough grinding position 302, a finish grinding position 303, a polishing position 304, and back to the carry-in / out position 301 by the rotation of the turntable 10.

[0031] The loading / unloading position 301 is an area where the workpiece 200 is loaded onto and unloaded from the holding table 20. The rough grinding position 302 is an area where the rough grinding unit 30 performs rough grinding (corresponding to machining) on ​​the workpiece 200 held on the holding table 20. The finish grinding position 303 is an area where the finish grinding unit 40 performs finish grinding (corresponding to machining) on ​​the workpiece 200 held on the holding table 20. The polishing position 304 is an area where the polishing unit 50 performs polishing (corresponding to machining) on ​​the workpiece 200 held on the holding table 20.

[0032] 1 and 4, the processing apparatus 1 includes a processing chamber 60 that houses the grinding wheels 31, 41 of the grinding units 30, 40 and the polishing wheel 51 of the polishing unit 50. As shown in Fig. 4, the processing chamber 60 includes a plurality of side walls 61 erected along the Z-axis direction from the apparatus base 2 and a ceiling wall 62 connected to the upper ends of the side walls 61, and houses the holding table 20 positioned at a rough grinding position 302, a finish grinding position 303, and a polishing position 304. The processing apparatus 1 also includes an upper opening 63 in the ceiling wall 62 through which the grinding wheels 31, 41 of the grinding units 30, 40 and the polishing wheel 51 of the polishing unit 50 can enter.

[0033] In the first embodiment, the turntable 10 has a partition wall 13 that separates the multiple holding tables 20, standing upright on the upper surface of the turntable cover 12. The partition wall 13 is located at the circumferential center between the holding tables 20, and in the embodiment, extends linearly along the radial direction of the turntable 10. For this reason, when the holding table 20 is positioned at the loading / unloading position 301, the grinding positions 302 and 303, and the polishing position 304, the partition wall 13 separates these positions 301, 302, 303, and 304.

[0034] The holding table 20 is accommodated in the processing chamber 60 at grinding positions 302, 303 and polishing position 304, and is positioned outside the processing chamber 60 at a carry-in / out position 301. For this reason, the turntable 10 serves as a holding table moving mechanism that can freely position the holding table 20 inside and outside the processing chambers 64, 65, 66 described below by rotating about its axis.

[0035] In addition, the processing chamber 60 accommodates the holding tables 20 positioned at the grinding positions 302, 303 and the polishing position 304, and is separated by a partition wall 13 between the holding tables 20 positioned at the grinding positions 302, 303 and the polishing position 304, so that, as shown in Figure 4, the partition wall 13 divides the processing chamber 60 into a first processing chamber 64 having an upper opening 63 through which the grinding wheel 31 of the rough grinding unit 30 can enter, a second processing chamber 65 having an upper opening 63 through which the grinding wheel 41 of the finish grinding unit 40 can enter, and a third processing chamber 66 having an upper opening 63 through which the polishing wheel 51 of the polishing unit 50 can enter.

[0036] Further, the processing chamber 60 has an entrance 67 (shown in FIG. 4) formed in each of the first processing chamber 64, the second processing chamber 65, and the third processing chamber 66, which allows the holding table 20 to enter and exit as the turntable 10 rotates. The entrance 67 is a space located at the center between the holding tables 20 in the circumferential direction when the holding table 20 is positioned at the loading / unloading position 301, the grinding positions 302, 303, and the polishing position 304, and is a space where the partition wall 13 is located when the holding table 20 is positioned at the loading / unloading position 301, the grinding positions 302, 303, and the polishing position 304. When the holding table 20 is positioned at the loading / unloading position 301, the grinding positions 302, 303, and the polishing position 304, the entrance 67 is blocked by the partition wall 13, so that chips generated during processing are prevented from scattering outside the processing chamber 60.

[0037] The rough grinding unit 30 is disposed above the holding table 20 positioned at the rough grinding position 302, and is a grinding unit equipped with a grinding wheel 31 for rough grinding having grinding stones 35 for rough grinding arranged in an annular shape for roughly grinding the back surface 205 exposed above of the workpiece 200 held by the holding table 20, and roughly grinds the back surface 205 of the workpiece 200 held on the holding surface 21 of the holding table 20 at the rough grinding position 302. That is, the rough grinding unit 30 has the grinding wheel 31 for roughly grinding the workpiece 200 held by the holding table 20.

[0038] The finish grinding unit 40 is disposed above the holding table 20 positioned at the rough grinding position 302, and is a grinding unit equipped with a finish grinding grinding wheel 41 having annularly arranged grinding stones 45 for finish grinding the back surface 205 of the workpiece 200 held by the holding table 20, and performs finish grinding of the back surface 205 of the workpiece 200 held on the holding surface 21 of the holding table 20 at the finish grinding position 303. That is, the finish grinding unit 40 has the grinding wheel 41 that performs finish grinding of the workpiece 200 held by the holding table 20.

[0039] In the grinding units 30, 40, the grinding wheels 31, 41 can be attached to the lower ends of spindles 33, 43 that are rotated around an axis parallel to the Z-axis direction by motors 32, 42. In the grinding units 30, 40, the grinding wheels 31, 41 are attached to the lower ends of the spindles 33, 43, and the grinding stones 35, 45 of the grinding wheels 31, 41 are disposed opposite the holding surface 21 of the holding table 20.

[0040] In the grinding units 30, 40, the spindles 33, 43 and the grinding wheels 31, 41 are rotated about their axes by the motors 32, 42, and grinding water is supplied from a nozzle (not shown) to the back surface 205 of the workpiece 200 held on the holding table 20 at the grinding positions 302, 303, while the feed unit 6 moves the grinding wheels 35, 45 toward the holding table 20 at a predetermined feed speed, thereby roughly grinding or finish grinding the back surface 205 of the workpiece 200. In the first embodiment, the grinding wheels 31, 41 include a plurality of grinding wheels 35, 45 arranged in an annular shape for roughly grinding or finish grinding the workpiece 200 held on the holding table 20, and a wheel base 36, 46 on which the grinding wheels 35, 45 are arranged in an annular shape and can be attached to the lower end of the spindles 33, 43.

[0041] The feed unit 6, which moves the grinding units 30, 40 in the Z-axis direction to relatively approach and move away from the holding table 20, is provided on an erect plate 7 erected from one end of the device base 2 in the X-axis direction parallel to the horizontal direction. The feed unit 6 includes a well-known ball screw provided rotatably about its axis, a well-known motor for rotating the ball screw about its axis, and a well-known guide rail that supports the spindle housings 37, 47 of the grinding units 30, 40 movably in the Z-axis direction.

[0042] In addition, in embodiment 1, the rough grinding unit 30 and the finish grinding unit 40 are arranged in such a way that the axis which is the center of rotation of the grinding wheels 31, 41 and the axis which is the center of rotation of the holding table 20 are parallel to each other with a horizontal gap between them, and the grinding wheels 35, 45 pass over the center of the back surface 205 of the workpiece 200 held on the holding table 20.

[0043] The polishing unit 50 is a processing unit that is disposed above the holding table 20 positioned at the polishing position 304, and is equipped with a polishing wheel 51 (shown in Figures 4 and 5) having a polishing pad 55 for polishing the exposed back surface 205 of the workpiece 200 held on the holding surface 21 of the holding table 20 at the polishing position 304.

[0044] 4 and 5, the polishing unit 50 can mount a polishing wheel 51 on the lower end of a spindle 53 that is rotated around an axis parallel to the Z-axis direction by a motor 52. In the polishing unit 50, the polishing wheel 51 is mounted on the lower end of the spindle 53, and a polishing pad 55 of the polishing wheel 51 is disposed opposite the holding surface 21 of the holding table 20.

[0045] The polishing unit 50 rotates the spindle 53 and the polishing wheel 51 around its axis using the motor 52 and supplies polishing water to the back surface 205 of the workpiece 200 held on the holding table 20 at the polishing position 304, while the feed unit 6 (shown in Figure 5) brings the polishing pad 55 closer to the holding table 20 at a predetermined feed speed, thereby polishing the back surface 205 of the workpiece 200.

[0046] In the first embodiment, the polishing wheel 51 includes a polishing pad 55 formed in a disk shape for polishing the workpiece 200 held on the holding table 20, and a wheel base 56 having the polishing pad 55 disposed on its underside and mountable to the lower end of the spindle 53. In the first embodiment, the polishing pad 55 is, for example, a polishing pad for dry polishing in which abrasive grains are dispersed in felt, but in the present invention, the polishing pad is not limited to the dry type and may be a polishing pad for wet polishing.

[0047] The feed unit 6, which moves the polishing unit 50 in the Z-axis direction to move relatively closer to and away from the holding table 20, is provided on an upright column 8 erected from the apparatus base 2. The feed unit 6 includes a well-known ball screw rotatably provided about its axis, a well-known motor for rotating the ball screw about its axis, and a well-known guide rail supporting a spindle housing 57 of the polishing unit 50 movably in the Z-axis direction. In the first embodiment, the polishing unit 50 is provided by a position adjustment unit 9 so as to be movable in the Y-axis direction which is parallel to the horizontal direction and perpendicular to the X-axis direction.

[0048] The processing apparatus 1 also includes a thickness meter 70 for detecting the thickness of the workpiece 200 held by the holding table 20, a contact-type thickness meter (not shown) is provided inside the first processing chamber 64, and a non-contact-type thickness meter 70 is provided inside the second processing chamber 65. In the first embodiment, the processing apparatus 1 includes a detection unit for detecting chip flying by detecting the height position of the back surface 205 of the workpiece 200 held by the holding table 20 positioned at least at the finish grinding position 303, and the non-contact-type thickness meter 70 functions as the detection unit. That is, in the first embodiment, the detection unit is disposed inside the processing chamber 60 (in the second processing chamber 65 in the first embodiment).

[0049] The thickness meter 70 includes a detection arm 71, the base end of which is supported on the device base 2 by a rotation mechanism (not shown) so as to be rotatable about an axis parallel to the Z-axis direction, and a detection unit 72, which is provided at the tip of the detection arm 71 and detects the thickness of the workpiece 200 from the time difference between when the light reflected by the back surface 205 of the workpiece 200 and the front surface (interface with the tape 206, which is a protective member) of the workpiece 200 is received. When the finish grinding unit 40 finishes grinding the workpiece 200, the thickness meter 70 detects the thickness of the workpiece 200 by positioning the detection unit 72 above the back surface 205 of the workpiece 200 held on the holding table 20 and irradiating light onto the back surface 205 of the workpiece 200. When the turntable 10 rotates to move the holding table 20 among the carry-in / out position 301 , the grinding positions 302 and 303 , and the polishing position 304 , the thickness meter 70 retracts the detection unit 72 from above the holding table 20 .

[0050] The cassette 220 is placed on the cassette mounting stage 3. The cassette 220 is a container having a plurality of slots for accommodating a plurality of workpieces 200. The cassette 220 accommodates a plurality of workpieces 200 before and after processing. In the first embodiment, a pair of cassette mounting stages 3 are provided, and a cassette 220 is placed on each of them. The cassette mounting stages 3 support the cassette 220 so that it can be raised and lowered freely along the Z-axis direction.

[0051] The alignment unit 4 is a table on which the workpiece 200 removed from the cassette 220 is temporarily placed and the center alignment is performed. The cleaning unit 5 cleans the workpiece 200 after processing, and removes contamination such as processing debris adhering to the back surface 205 that has been ground and polished.

[0052] The transport unit 80 transports the workpiece 200. The transport unit 80 includes a first transport unit 81 and a second transport unit 82. The first transport unit 81 takes out the workpiece 200 before processing from the cassette 220 and transports it to the alignment unit 4, and takes out the workpiece 200 after processing from the cleaning unit 5 and transports it to the cassette 220. The first transport unit 81 is, for example, a robot pick equipped with a U-shaped hand, and transports the workpiece 200 by suction and holding it with the U-shaped hand.

[0053] The second transport unit 82 has a suction pad that suctions the workpiece 200. The second transport unit 82 suctions and holds the unprocessed workpiece 200 aligned by the alignment unit 4 onto the suction pad, and carries it onto the holding table 20 positioned at the carry-in / out position 301. The second transport unit 82 suctions and holds the ground workpiece 200 on the holding table 20 positioned at the carry-in / out position 301 onto the suction pad, and carries it out to the cleaning unit 5.

[0054] The control unit 100 controls each of the above-mentioned constituent units constituting the processing apparatus 1, and causes the processing apparatus 1 to execute a processing operation on the workpiece 200. The control unit 100 is a computer having an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory), and an input / output interface device.

[0055] The arithmetic processing device of the control unit 100 performs arithmetic processing according to a computer program stored in the storage device, and outputs a control signal for controlling the processing device 1 to the above-mentioned components of the processing device 1 via the input / output interface device. The control unit 100 is also connected to a display unit configured with a liquid crystal display device or the like for displaying the status and images of the processing operation, an input unit used by the operator to register processing content information, and a notification unit for notifying the operator.

[0056] The input unit is composed of at least one of a touch panel provided on the display unit, a keyboard, etc. The notification unit notifies the operator by emitting at least one of sound, light, and a message on the touch panel.

[0057] (Processing method) Next, a processing method according to the first embodiment will be described with reference to the drawings. Fig. 6 is a flow chart showing the flow of the processing method according to the first embodiment. The processing method according to the first embodiment is a method of grinding and polishing the back surface 205 of the workpiece 200 to divide the workpiece 200 into a plurality of chips 212. As shown in Fig. 6, the processing method includes a surface protection step 1001, a division start point formation step 1002, a holding step 1003, a grinding step 1004, a confirmation step 1005, a polishing step 1006, and a carrying out step 1007.

[0058] (Surface protection step) Fig. 7 is a perspective view showing a surface protection step in the processing method shown in Fig. 6. The surface protection step 1001 is a step of attaching a tape 206, which is a protective member, to the surface 202 side of the workpiece 200.

[0059] In the first embodiment, in the surface protection step 1001, as shown in Fig. 7, a tape 206 having the same diameter as the workpiece 200 is placed against the surface 202 of the workpiece 200, and then the tape 206 is attached to the surface 202 of the workpiece 200. In the first embodiment, the tape 206 is used as the protective member, but in the present invention, the protective member is not limited to the tape 206.

[0060] In the first embodiment, the tape 206 is an adhesive tape that includes a base layer made of a non-adhesive and flexible resin and a glue layer that is laminated on the base layer and made of an adhesive and flexible resin, and the glue layer is attached to the surface 202 of the workpiece 200. In the present invention, the tape 206 may be a sheet that does not include a glue layer and is made of only a base material made of a thermoplastic resin, and is attached to the surface 202 of the workpiece 200 by heating.

[0061] (Splitting point formation step) Fig. 8 is a side view, partially in section, showing the splitting start point forming step of the processing method shown in Fig. 6. Fig. 9 is a perspective view showing an example of a workpiece on which a modified layer serving as a splitting start point is formed by the splitting start point forming step of the processing method shown in Fig. 6.

[0062] The splitting starting point formation step 1002 is a step in which a laser beam 116 having a wavelength (in this embodiment, 1300 nm to 1064 nm) that is transparent to the substrate 201 of the workpiece 200 is irradiated along the intended splitting line 203 from the back surface 205 side of the substrate 201 of the workpiece 200, and a modified layer 207 that is a splitting starting point along the intended splitting line 203 is formed inside the substrate 201 of the workpiece 200.

[0063] The modified layer 207 means a region in which the density, refractive index, mechanical strength, and other physical properties are different from those of the surrounding area, and examples of such regions include a melting treatment region, a crack region, a dielectric breakdown region, a refractive index change region, and a region in which these regions are mixed, etc. The modified layer 207 has a lower mechanical strength, etc. than other parts of the workpiece 200.

[0064] In the first embodiment, in the division starting point forming step 1002, the laser processing device 110 suction-holds the front surface 202 side of the substrate 201 of the workpiece 200 to the holding surface 112 of the holding table 111 via the tape 206. In the division starting point forming step 1002, the laser processing device 110 relatively moves the holding table 111 and the laser beam application unit 113 along the planned division line 203, while setting a focusing point 115 inside the substrate 201 with the focusing lens 114 as shown in Fig. 8, and irradiates a pulsed laser beam 116 from the laser beam application unit 113 along the planned division line 203.

[0065] In the first embodiment, in the split start point forming step 1002, since the laser beam 44 has a wavelength that is transparent to the workpiece 200, a modified layer 207 is formed inside the substrate 201 along the intended split line 203, as shown in Fig. 8. In the split start point forming step 1002, the modified layer 207 is desirably located in a position in the thickness direction of the workpiece 200 that will be removed in the grinding step 1004 inside the substrate 201.

[0066] In the first embodiment, in the dividing start point forming step 1002, when modified layers 207 are formed inside the substrate 201 along all of the planned dividing lines 203 as shown in Fig. 9, the irradiation of the laser beam 44 and the suction holding of the holding table 20 are released. The subsequent holding step 1003, grinding step 1004, checking step 1005, polishing step 1006 and carrying out step 1007 are performed by the processing device 1.

[0067] (holding step) Fig. 10 is a side view, partially in cross section, typically showing the holding step of the processing method shown in Fig. 6. The holding step 1003 is a step of holding the workpiece 200 on the holding table 20. In the first embodiment, the holding step 1003 is performed by the processing device 1 when the cassette 220 accommodating the workpiece 200 having the tape 206 attached to the surface 202 is placed on the cassette placement table 3 of the device base 2 of the processing device 1, the processing conditions are registered in the control unit 100 by the operator, and the control unit 100 receives an instruction to start the processing operation from the operator.

[0068] In the embodiment 1, in the holding step 1003, the control unit 100 of the processing apparatus 1 rotates the spindles 33, 43 of the grinding units 30, 40 about their axes at rotation speeds determined by the processing conditions. In the embodiment 1, in the processing operation, the processing apparatus 1 causes the first transport unit 81 to take out one workpiece 200 from any one of the cassettes 220 and carry it into the alignment unit 4, and causes the alignment unit 4 to align the center of the workpiece 200.

[0069] In the holding step 1003 in the first embodiment, the processing apparatus 1 causes the control unit 100 to suction-hold the workpiece 200 aligned with the suction pad of the second transport unit 82, and causes the second transport unit 82 to carry it onto the holding surface 21 of the holding table 20 positioned at the carry-in / out position 301. In the holding step in the first embodiment, as shown in Fig. 10, the processing apparatus 1 causes the control unit 100 to suction-hold the workpiece 200 via the tape 206 onto the holding surface 21 of the holding table 20 positioned at the carry-in / out position 301.

[0070] (Grinding step) Fig. 11 is a side view, partially in cross section, showing a schematic diagram of the grinding step of the processing method shown in Fig. 6. In the grinding step 1004, the back surface 205 of the workpiece 200 held on the holding table 20 is ground with the grinding wheels 31, 41 to divide the workpiece 200 into a plurality of chips 212 from the modified layer 207.

[0071] In the first embodiment, in the grinding step 1004, the control unit 100 of the processing device 1 rotates the turntable 10, and transports the holding table 20 holding the workpiece 200 at the carry-in / out position 301 to the rough grinding position 302 and the finish grinding position 303 in that order. In the first embodiment, in the grinding step 1004, the processing device 1 rotates the grinding wheels 31, 41 by the spindles 33, 43 and rotates the holding table 20 about its axis while supplying grinding water, and brings the grinding wheels 35, 45 into contact with the back surface 205 of the substrate 201 of the workpiece 200 and approaches the holding table 20 at a predetermined feed rate at the rough grinding position 302 and the finish grinding position 303, as shown in FIG. In embodiment 1, for example, in rough grinding, the thickness of the workpiece 200 is detected with a contact thickness meter (not shown) while the workpiece 200 is ground until it reaches a thickness at which it will not be divided, and in finish grinding, the thickness of the workpiece 200 is detected with a non-contact thickness meter 70 that also functions as a detection unit while the workpiece 200 is ground until it reaches a predetermined finishing thickness, thereby dividing the workpiece 200 into a plurality of chips 212.

[0072] Then, in the grinding step 1004 in the first embodiment, since the workpiece 200 has the modified layer 207 formed inside the substrate 201, the workpiece 200 is divided into chips 212 along the division lines 203 starting from the modified layer 207 by grinding stress acting from the grinding wheels 31, 41 of the grinding units 30, 40. In the grinding step 1004, since the workpiece 200 on which the modified layer 207 is formed is divided into a plurality of chips 212, the processing device 1 and processing method according to the first embodiment roughly grind and finish grind the workpiece 200 on which the modified layer 207 is formed along the intersecting plurality of division lines 203, and divide it into a plurality of chips 212 along the division lines 203.

[0073] In the first embodiment, in the grinding step 1004, the processing apparatus 1 performs finish grinding on the workpiece 200 held on the holding table 20 positioned at the rough grinding position 302 with the finish grinding unit 40 until the workpiece 200 reaches a predetermined thickness while detecting the thickness of the workpiece 200 held on the holding table 20 positioned at the rough grinding position 302 with the thickness meter 70. In the first embodiment, in the grinding step 1004, the processing apparatus 1 raises the grinding wheel 41 of the finish grinding unit 40 when finish grinding of the back surface 205 of the workpiece 200 held on the holding table 20 positioned at the rough grinding position 302 is completed.

[0074] In the grinding step 1004, particularly when the finish grinding process is performed to thin the workpiece 200 to a predetermined thickness, some chips 212 may peel off from the tape 206 and fly off the holding surface 21 of the holding table 20, which is called chipping. In particular, the scraps 211 shown in hatched areas in FIG. 3 located on the outer edge are likely to fly off the holding surface 21, that is, the scraps 211 are likely to cause chipping. In addition, the workpiece 200 after the grinding step 1004 has a fractured layer (not shown) formed on the surface layer of the back surface 205. The fractured layer is processing distortion such as crystal defects and distortion.

[0075] (Confirmation step) Fig. 12 is a plan view showing a schematic diagram of a confirmation step of the processing method shown in Fig. 6. The confirmation step 1005 is a step for confirming the presence or absence of chipping of the workpiece 200. In the first embodiment, in the confirmation step 1005, the processing device 1 rotates the holding table 20 positioned at the finish grinding position about its axis while swinging the detection arm 71 of the thickness gauge 70 functioning as a detection unit about its base end, and detects the entire thickness of the workpiece 200 after the finish grinding process held by the holding table 20 positioned at the finish grinding position with the detection unit (thickness gauge) 70, as shown in Fig. 12.

[0076] In the first embodiment, in the confirmation step 1005, the processing device 1 determines whether or not any of the thicknesses detected by the detection unit (thickness meter) 70 is thinner than a predetermined threshold value. In the first embodiment, in the confirmation step 1005, if the control unit 100 determines that any of the thicknesses detected by the detection unit (thickness meter) 70 is thinner than a predetermined threshold value, the processing device 1 determines that chipping has occurred. In the confirmation step 1005, if the control unit 100 determines that any of the thicknesses detected by the detection unit (thickness meter) 70 is not thinner than a predetermined threshold value, the processing device 1 determines that chipping has not occurred. Also, in the first embodiment, in the confirmation step 1005, if the control unit 100 determines that any of the thicknesses detected by the detection unit (thickness meter) 70 is thinner than a predetermined threshold value, the processing device 1 desirably notifies the operator of the occurrence of chipping by the notification unit and interrupts the processing operation of the processing device 1.

[0077] Thus, in the first embodiment, the confirmation step 1005 is performed after the grinding step 1004 is performed, and the thickness meter 70 is a detection unit that detects chipping of the workpiece 200. Also, in the first embodiment, the confirmation step 1005 is performed by detecting the thickness of the workpiece 200 held by the holding table 20 with a detection unit (thickness meter), and the presence or absence of chipping of the workpiece 200 is confirmed by the thickness meter 70, which is a detection unit that detects chipping of the workpiece 200.

[0078] (Polishing step) The polishing step 1006 is a step of polishing the back surface 205 side of the workpiece 200 ground in the grinding step 1004 with the polishing pad 55, and removing the fractured layer formed in the grinding step 1004. In the first embodiment, in the polishing step 1006, the processing device 1 rotates the turntable 10 to move the holding table 20 holding the workpiece 200 after the finish grinding to the polishing position 304, and at the polishing position 304, the polishing pad 55 is brought into contact with the back surface 205 of the substrate 201 of the workpiece 200 and brought close to the holding table 20 at a predetermined feed rate while rotating the polishing wheel 51 by the spindle 53 and rotating the holding table 20 about its axis, thereby polishing the back surface 205 of the workpiece 200 with the polishing pad 55. In the first embodiment, in the polishing step 1006, for example, dry polishing is performed using a polishing pad 55 having abrasive grains dispersed in felt. However, in the present invention, in addition to dry polishing, wet polishing may also be performed, and for example, CMP (Chemical Mechanical Polishing) may be performed in which polishing is performed while supplying a slurry.

[0079] In embodiment 1, in the polishing step 1006, when the processing apparatus 1 performs polishing for a predetermined time, it terminates the polishing process by the polishing unit 50, raises the polishing unit 50, rotates the turntable 10, and positions the workpiece 200 polished by the polishing unit 50 at the loading / unloading position 301.

[0080] (Exit step) The carrying-out step 1007 is a step of carrying out the workpiece 200 after grinding and polishing from the holding table 20. In the first embodiment, in the carrying-out step 1007, the processing apparatus 1 stops suction holding of the workpiece 200 after grinding and polishing on the holding table 20 positioned at the carry-in / out position 301, and carries the workpiece 200 from the holding table 20 positioned at the carry-in / out position to the cleaning unit 5 by the second transport unit 82. In the first embodiment, in the carrying-out step 1007, the processing apparatus 1 washes the workpiece 200 in the cleaning unit 5, and carries the washed workpiece 200 into the cassette 220 by the first transport unit 81.

[0081] Thus, in the grinding step 1004 and the polishing step 1006, the processing device 1 conveys the workpiece 200 to the rough grinding position 302, the finish grinding position 303, the polishing position 304, and the carry-in / out position 301 in this order using the turntable 10, and performs rough grinding, finish grinding, and polishing in this order. In addition, every time the turntable 10 rotates 90 degrees, the processing device 1 carries out the workpiece 200 after grinding and polishing from the holding table 20 positioned at the carry-in / out position 301, carries the workpiece 200 before grinding and polishing into the holding table 20 positioned at the carry-in / out position 301, roughly grinds the workpiece 200 before rough grinding, finish grinds the workpiece 200 after rough grinding, and polishes the workpiece 200 after finish grinding. When all of the workpieces 200 in the cassette 220 have been ground and polished, the processing device 1 ends the processing operation.

[0082] The processing apparatus 1 of the embodiment 1 described above is equipped with a thickness meter 70 which is a detection unit that detects chipping of the workpiece 200, and the processing method of the embodiment 1 is equipped with a confirmation step 1005 in which the thickness meter 70 which is a detection unit that detects chipping of the workpiece 200 is used to confirm whether or not there is chipping of the workpiece 200, so that chipping during processing operation can be detected.

[0083] As a result, the processing device 1 and processing method according to the first embodiment have the effect of making it possible to grasp chip flying during processing.

[0084] In addition, the processing apparatus 1 and processing method of embodiment 1 detect chip flying using a thickness meter 70 that detects the height position of the back surface 205 of the workpiece 200 held on the holding table 20, thereby simplifying the device configuration.

[0085] [Embodiment 2] A processing device and a processing method according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 13 is a perspective view that shows a typical configuration example of a processing device according to the second embodiment. FIG. 14 is a flow chart showing a flow of a processing method according to the second embodiment. FIG. 15 is a side view that shows a typical partial cross section of a grinding step and a checking step of the processing method shown in FIG. 14. FIG. 16 is a side view that shows a typical partial cross section of another example of the grinding step and the checking step shown in FIG. 15. In addition, in FIGS. 13, 14, 15, and 16, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0086] The processing apparatus 1 according to the second embodiment is equipped with an imaging unit 90 as a detection unit as shown in FIG. 13, and the processing method according to the second embodiment is the same as that of the first embodiment, except that the confirmation step 1005 is performed during the grinding step 1004 as shown in FIG. 14.

[0087] In the second embodiment, the imaging unit 90 is disposed above the holding table 20 positioned at the finish grinding position 303 in the second processing chamber 65 of the processing chamber 60. In the second embodiment, the imaging unit 90 includes an imaging element such as a CCD (Charge Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element, images the workpiece 200 held by the holding table 20 positioned at the finish grinding position, forms an image of the workpiece 200, and outputs the image to the control unit 100. The imaging unit 90 detects chip flying by forming an image of the workpiece 200. In the second embodiment, the imaging unit 90 is a well-known line sensor.

[0088] In the second embodiment, in the grinding step 1004, while the finish grinding unit 40 is finish grinding the workpiece 200, the imaging unit 90 captures the back surface 205 of the workpiece 200 being finish ground, as shown in FIG. 14 and FIG. 15, and performs the confirmation step 1005. In the second embodiment, in the confirmation step 1005, the imaging unit 90 captures the back surface 205 of the workpiece 200 being finish ground with the imaging element of the imaging unit 90, forms a captured image, and outputs the formed captured image to the control unit 100. In the second embodiment, in the confirmation step 1005, the control unit 100 detects chip flying based on the captured image and confirms the presence or absence of chip flying. In the second embodiment, the processing device 1 may also include a moving unit that moves the imaging unit 90 in the radial direction of the holding table 20 during the confirmation step 1005.

[0089] In the present invention, the processing apparatus 1 may have a water film forming unit 91 attached to the imaging unit 90 as shown in FIG. 16. The water film forming unit 91 supplies pure water from a liquid supply source 93 through an on-off valve 92 between the imaging unit 90 and the back surface 205 of the workpiece 200 to form a water film 94 made of pure water between the imaging unit 90 and the back surface 205 of the workpiece 200. In the processing apparatus 1 shown in FIG. 16, in the confirmation step 1005, the imaging unit 90 images the back surface 205 through the water film 94 while the water film forming unit 91 forms the water film 94. In the case shown in FIG. 16, since the image is captured through the water film 94, it is possible to capture the image without being affected by the grinding fluid, and it is possible to prevent a failure to detect chip flying due to the grinding fluid being captured in the captured image.

[0090] The processing apparatus 1 of embodiment 2 is equipped with an imaging unit 90 which is a detection unit that detects chipping of the workpiece 200, and the processing method of embodiment 2 is equipped with a confirmation step 1005 in which the imaging unit 90 which is a detection unit that detects chipping of the workpiece 200 confirms whether or not there is chipping of the workpiece 200, so that chipping during processing operation can be detected.

[0091] As a result, the processing device 1 and processing method according to the second embodiment, like the first embodiment, have the effect of making it possible to grasp chip flying during processing.

[0092] In addition, the processing device 1 according to the second embodiment is provided with the imaging unit 90, which is a detection unit, inside the processing chamber 60, and performs the confirmation step 1005 during the grinding step 1004. This makes it possible to detect chip flying while performing grinding, and thus to detect chip flying at more precise timing without reducing productivity.

[0093] [Embodiment 3] A processing device and a processing method according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 17 is a side view, partly in section, that typically illustrates a confirmation step of the processing device according to the third embodiment. In Fig. 17, the same parts as those in the first and second embodiments are given the same reference numerals, and the description thereof will be omitted.

[0094] As shown in Fig. 17, the processing apparatus 1 according to the third embodiment is similar to the first and second embodiments except that it includes an imaging unit 90 as a detection unit as in the second embodiment, and a confirmation step 1005 is performed after the grinding step 1004 as in the first embodiment. Note that Fig. 17 shows an example in which a water film forming unit 91 is attached, but in the present invention, the water film forming unit 91 does not need to be attached. Also, in the third embodiment, after the grinding step 1004 is completed, the confirmation step 2005 is performed on the workpiece 200 immediately after the grinding step is completed in the second processing chamber 65 while the workpiece 200 is held by the holding table 20.

[0095] In the processing apparatus 1 and processing method of embodiment 3, the processing apparatus 1 is equipped with an imaging unit 90 which is a detection unit, and the processing method includes a confirmation step 1005 in which the imaging unit 90 is used to confirm whether or not there is any chipping of the workpiece 200. Therefore, chipping during processing can be detected, and similar to embodiment 1, it is possible to grasp chipping during processing.

[0096] [Embodiment 4] A processing device and a processing method according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 18 is a side view showing a cross section of a processing chamber of a processing device according to the fourth embodiment. Fig. 19 is a side view showing a schematic cross section of a confirmation step of a processing method according to the fourth embodiment. In Figs. 18 and 19, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof will be omitted.

[0097] The processing apparatus 1 according to the fourth embodiment is the same as the first embodiment, except that the detection unit is disposed above the entrance 67 of the processing chamber 60, as shown in Fig. 18. In the example shown in Fig. 18, the imaging unit 90, which is the detection unit, is attached to the upper part of the entrance 67 between the second processing chamber 65 and the third processing chamber 66 and to the lower surface of the ceiling wall 62 of the processing chamber 60, and is disposed above the partition wall 13 when the holding table 20 is positioned at the positions 301, 302, 303, and 304 described above.

[0098] In the processing method according to the fourth embodiment, the confirmation step 1005 is performed after the grinding step 1004, and the turntable 10 rotates and the workpiece 200 after the rough grinding process moves to the polishing position, while the imaging unit 90, which is a detection unit, detects the chip flying, as shown in Fig. 19. Note that in the present invention, the detection unit may be the detection unit 72 of the thickness gauge 70, as in the first embodiment.

[0099] In the processing apparatus 1 and processing method of embodiment 4, the processing apparatus 1 is equipped with an imaging unit 90 which is a detection unit, and the processing method includes a confirmation step 1005 in which the imaging unit 90 is used to confirm whether or not there is any chipping of the workpiece 200. Therefore, chipping during processing can be detected, and similar to embodiment 1, it is possible to grasp chipping during processing.

[0100] Moreover, in the processing apparatus 1 and processing method according to the fourth embodiment, the checking step 1005 is performed while the turntable 10 is rotating, that is, while the holding table 20 is moving, so that productivity is not reduced.

[0101] The present invention is not limited to the above embodiment. In other words, various modifications can be made without departing from the gist of the present invention. In the embodiment, the processing device 1 includes the grinding units 30, 40 and the polishing unit 50, but the present invention is not limited to this and may include at least one grinding unit. In the present invention, for example, only one grinding unit may be provided and only one upper opening 63 may be formed in the processing chamber 60. [Explanation of symbols]

[0102] 1 Processing equipment 10 Turntable (holding table moving mechanism) 20 Holding Table 30 Rough grinding unit (grinding unit) 31 Grinding Wheel 40 Finish grinding unit (grinding unit) 41 Grinding Wheel 64 1st processing room (processing room) 65 2nd processing room (processing room) 66 3rd processing room (processing room) 67 Entrance / Exit 70 Thickness gauge (detection unit) 90 Imaging unit (detection unit) 200 Workpiece 202 Surface 203 Division line 204 Devices 205 Back side (top side) 207 Modified layer 212 Chips 1003 Retention Step 1004 Grinding step 1005 Confirmation Step

Claims

1. A processing device for processing a workpiece having division starting points formed along a plurality of intersecting division lines and dividing the workpiece into a plurality of chips along the division lines, A holding table for holding the workpiece; a grinding unit having a grinding wheel for grinding the workpiece held by the holding table; and a detection unit that detects chipping of the workpiece.

2. 2. The processing apparatus according to claim 1, wherein the detection unit detects the chip flying by detecting a height position of an upper surface of the workpiece held by the holding table.

3. 2. The processing apparatus according to claim 1, wherein the detection unit includes an image pickup element, forms an image of the workpiece held by the holding table, and detects the chip flying based on the image.

4. The processing apparatus includes a processing chamber that houses the grinding unit; a holding table moving mechanism capable of freely positioning the holding table inside and outside the processing chamber; an entrance for allowing the holding table to enter and exit the processing chamber is formed; 4. The processing apparatus according to claim 2, wherein the detection unit is disposed inside the processing chamber.

5. The processing apparatus includes a processing chamber that houses the grinding unit; a holding table moving mechanism capable of freely positioning the holding table inside and outside the processing chamber; an entrance for allowing the holding table to enter and exit the processing chamber is formed; 4. The processing device according to claim 2, wherein the detection unit is disposed above the entrance.

6. A processing method for dividing a workpiece having division starting points formed along a plurality of intersecting division lines into a plurality of chips along the division lines, comprising the steps of: a holding step of holding the workpiece on a holding table; a grinding step of grinding the workpiece held by the holding table with a grinding wheel and dividing the workpiece into a plurality of chips from the division starting points; and a confirmation step of confirming whether or not chips have been scattered on the workpiece by a detection unit that detects chips of the workpiece.

7. 7. The machining method according to claim 6, wherein the checking step includes detecting a height position of an upper surface of the workpiece held by the holding table.

8. 7. The machining method according to claim 6, wherein the checking step includes forming an image of the workpiece held on the holding table by an imaging element, and checking for the presence or absence of the flying chip based on the image.

9. The processing method according to claim 7 or 8, wherein the checking step is performed after the grinding step is performed.

10. The method of claim 8 , wherein the verifying step is performed during the grinding step.

Images