JP2018187688A - Processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably prevent a processing failure of a work-piece due to turn over of the work-piece.SOLUTION: A processing device comprising; a chuck table which holds a work-piece onto a front face of which a protective tape is bonded; processing means for processing a rear face of the work-piece held by the chuck table; front and rear detection means which detects the front and rear of the work-piece before the work-piece is loaded on the chuck table. The front and rear detection means is so configured as to detect whether a top face of th work-piece is the front face onto which the protective tape is bonded or the rear face onto which the protective tape is not bonded by a difference in wettability of the top face of the work-piece loaded on a horizontal holding surface.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a processing apparatus that performs various types of processing on a workpiece.

  In the semiconductor device manufacturing process, device chips are manufactured by subjecting a workpiece such as a semiconductor wafer to various processes such as grinding and cutting. For example, in a grinding process, a workpiece on which a circuit such as an IC is formed is ground to a predetermined thickness in order to realize a reduction in size and weight of the divided device chip. In this case, a protective tape is attached to the surface side of the workpiece, and the back side of the workpiece exposed on the chuck table is predetermined by the grinding wheel while the protective tape side is sucked and held by the chuck table of the grinding device. Grind to thickness.

  By the way, in the grinding apparatus described in Patent Document 1, the workpiece is automatically carried from the cassette and placed on the chuck table. However, the workpiece is accommodated in the cassette in a state where the workpiece is turned upside down. There is. In other words, the workpiece is usually stored in the cassette with the protective tape side facing down, but in some cases, the workpiece is accidentally stored in the cassette with the protective tape side facing up. There is also a thing. In such a case, a serious problem has been pointed out that the protective tape side is ground by the grinding wheel, and the circuit on the surface side of the workpiece is destroyed and becomes defective.

  In order to solve this problem, there has been proposed a grinding apparatus provided with front and back detection means for detecting the front and back of a workpiece (for example, see Patent Document 1). In the grinding apparatus described in Patent Literature 2, a color sensor and a hardness sensor are provided as front and back detection means on the holding surface of the transport robot that pulls out the workpiece from the cassette. The presence or absence of the protective tape is detected by the color sensor or the hardness sensor, and the front and back of the workpiece are recognized before the workpiece is placed on the chuck table. Thereby, even when the workpiece is stored in the cassette upside down, the surface side of the workpiece is prevented from being ground by the grinding wheel.

JP 2001-028355 A

  However, in the front and back detection means described in Patent Document 2, the color sensor does not function in the case of a colorless and transparent protective tape, and in the case of a high hardness protective tape, the hardness sensor may not be able to detect it. For this reason, depending on the type of the protective tape, it is not possible to detect the reverse of the workpiece, and there is a possibility that the workpiece is processed in a state where the workpiece is reversed inside the cassette.

  This invention is made | formed in view of this point, and it is set as one of the objectives to provide the processing apparatus which can prevent the processing defect of the workpiece resulting from the front-and-back inversion of a workpiece reliably.

  A processing apparatus according to an aspect of the present invention includes at least a chuck table that holds a workpiece having a protective tape attached to a surface thereof, and a processing unit that processes a back surface of the workpiece held on the chuck table. The processing apparatus includes a front and back detection means for detecting the front and back of the workpiece before the workpiece is placed on the chuck table, and the front and back detection means is placed on the horizontal holding surface. It is characterized in that it is detected whether the surface on which the droplets are dropped is the surface to which the protective tape is attached or the back surface to be processed due to the difference in wettability of the droplets dropped on the upper surface of the workpiece.

  According to this configuration, when a droplet is dropped on the workpiece, the droplet swells on the surface of the workpiece without spreading due to the water repellency of the protective tape, and on the back surface of the workpiece, the droplet drops due to hydrophilicity. Spreads into a film. By using such a difference in wettability of the workpiece, it is possible to accurately detect whether the surface of the workpiece to which the protective tape is attached or the back surface of the workpiece to which the protective tape is not attached. It is possible to reliably prevent processing defects caused by the reverse of the workpiece.

  In the processing apparatus according to an aspect of the present invention, the front and back detection unit images a droplet dropping unit that drops a predetermined amount of droplets and a droplet that is dropped from the droplet dropping unit onto the upper surface of the workpiece. Compared with the reference image information, an image pickup unit, a reference image information storage unit that picks up images of the droplets dropped from the droplet dropping unit on the front surface and / or the back surface in advance and stores them as reference image information. And a determination unit that determines that the surface on which the droplet is dropped is the front surface or the back surface.

  According to the present invention, by utilizing the difference in wettability of the work piece, it is possible to accurately determine whether the surface of the work piece has the protective tape attached or the back face of the work piece to which the protective tape is not attached. Therefore, it is possible to prevent processing defects caused by the front and back inversion of the workpiece.

It is a perspective view of the grinding device of this embodiment. It is a schematic diagram of the front and back detection means of this Embodiment. It is explanatory drawing of the judgment process of the front and back of the to-be-processed object of this Embodiment. It is explanatory drawing of the detection operation of the front and back detection means of this Embodiment.

  Hereinafter, the grinding apparatus according to the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the grinding apparatus of the present embodiment. The grinding device is not limited to the configuration shown in FIG. 1 and may be configured in any way as long as it is a device that grinds a workpiece with a grinding wheel.

  As shown in FIG. 1, the grinding apparatus 1 is a full-auto type grinding apparatus, and performs a series of operations including carry-in processing, rough grinding processing, finish grinding processing, cleaning processing, and carry-out processing on the workpiece W. It is configured to be fully automated. The workpiece W is formed in a substantially disk shape, and is carried into the grinding apparatus 1 while being accommodated in the cassette C. The workpiece W is a silicon wafer having a device formed on the surface, and a protective tape T is attached to the surface of the workpiece W. The protective tape T is formed by laminating an adhesive layer on a tape base material of a synthetic resin such as polyolefin (PO).

  A pair of cassettes C in which a plurality of workpieces W are accommodated are placed on the front side of the base 10 of the grinding apparatus 1. Behind the pair of cassettes C, a cassette robot 15 is provided for taking a workpiece W into and out of the cassettes C. Next to one cassette C, a positioning mechanism 20 for positioning the workpiece W before processing is provided, and next to the other cassette C, a cleaning mechanism 25 for cleaning the processed workpiece W is provided. Yes. Between the positioning mechanism 20 and the cleaning mechanism 25, there are a carry-in means 30 for carrying the workpiece W before machining into the chuck table 41 and a carry-out means 35 for carrying out the workpiece W after machining from the chuck table 41. Is provided.

  The cassette robot 15 is configured by providing a hand portion 17 at the tip of a robot arm 16 composed of a multi-node link. In the cassette robot 15, the workpiece W before processing is transferred from the cassette C to the positioning mechanism 20, and the processed workpiece W is transferred from the cleaning mechanism 25 to the cassette C. The positioning mechanism 20 is configured by arranging a plurality of positioning pins 22 that can move forward and backward with respect to the center of the position table 21 around the position table 21. In the positioning mechanism 20, the center of the workpiece W is positioned at the center of the position table 21 by a plurality of positioning pins 22 being abutted against the outer peripheral edge of the workpiece W placed on the position table 21. .

  The carry-in means 30 is configured by providing a carry-in pad 32 at the tip of a carry-in arm 31 that can turn on the base 10. In the carry-in means 30, the workpiece W is lifted from the position table 21 by the carry-in pad 32, and the workpiece W is carried into the chuck table 41 by turning the carry-in pad 32 by the carry-in arm 31. The carry-out means 35 is configured by providing a carry-out pad 37 at the tip of a carry-out arm 36 that can turn on the base 10. In the unloading means 35, the workpiece W is lifted from the chuck table 41 by the unloading pad 37, and the workpiece W is unloaded from the chuck table 41 by turning the unloading pad 37 by the unloading arm 36.

  The cleaning mechanism 25 is configured by providing various nozzles (not shown) that spray cleaning water and dry air toward the spinner table 26. In the cleaning mechanism 25, the spinner table 26 holding the workpiece W is lowered into the base 10, and cleaning water is sprayed in the base 10 to spin the workpiece W, and then dry air is sprayed. As a result, the workpiece W is dried. Behind the carry-in means 30 and the carry-out means 35 is provided a turntable 40 in which four chuck tables 41 are rotatably arranged at equal intervals in the circumferential direction. A holding surface 42 that holds the workpiece W is formed on the upper surface of each chuck table 41.

  When the turntable 40 is intermittently rotated at 90 ° intervals, a loading position where the workpiece W is carried in, a rough grinding position facing the rough grinding means 56, a finish grinding position facing the finish grinding means 66, and the workpiece. The chuck table 41 is sequentially positioned at the unloading position where W is unloaded. At the rough grinding position, the workpiece W is roughly ground to a predetermined thickness by the rough grinding means 56. At the finish grinding position, the finish grinding means 66 finish-grinds the workpiece W after the rough grinding to the finish thickness. On the rear side of the turntable 40, an upright wall portion 11 that supports the rough grinding means 56 and the finish grinding means 66 is provided above the rough grinding position and the finish grinding position.

  The standing wall portion 11 is provided with a drive mechanism 50 that moves the rough grinding means 56 up and down. The drive mechanism 50 includes a pair of guide rails 51 disposed in front of the standing wall 11 and parallel to the Z-axis direction, and a Z-axis table 52 slidably installed on the pair of guide rails 51. A rough grinding means 56 is supported on the front surface of the Z-axis table 52. The standing wall portion 11 is partially opened (not shown), and the nut portion of the Z-axis table 52 is screwed to a ball screw (not shown) on the back side of the standing wall portion 11 through the opening. The rough grinding means 56 is moved along the guide rail 51 in the Z-axis direction by the rotational drive of the drive motor 55 provided at one end of the ball screw.

  The standing wall 11 is provided with a drive mechanism 60 that moves the finish grinding means 66 up and down. The drive mechanism 60 has a pair of guide rails 61 arranged in front of the standing wall portion 11 and parallel to the Z-axis direction, and a Z-axis table 62 slidably installed on the pair of guide rails 61. Finish grinding means 66 is supported on the front surface of the Z-axis table 62. The standing wall portion 11 is partially opened (not shown), and the nut portion of the Z-axis table 62 is screwed to a ball screw (not shown) on the back side of the standing wall portion 11 through the opening. The finish grinding means 66 is moved in the Z-axis direction along the guide rail 61 by the rotational drive of the drive motor 65 provided at one end of the ball screw.

  A mount 58 is provided at the lower end of the spindle 57 of the rough grinding means 56, and a rough grinding wheel 59 in which a plurality of rough grinding wheels are annularly arranged is mounted on the lower surface of the mount 58. The rough grinding wheel is composed of, for example, a diamond grinding stone in which diamond abrasive grains are hardened with a binder such as metal bond or resin bond. In addition, a mount 68 is provided at the lower end of the spindle 67 of the finish grinding means 66, and a grinding wheel 69 for finish grinding having a plurality of finish grinding wheels arranged in an annular shape is mounted on the lower surface of the mount 68. The finish grinding wheel is composed of abrasive grains having a smaller particle diameter than the coarse grinding wheel.

  In addition, the grinding apparatus 1 is provided with a control means 80 that controls each part of the apparatus. The control unit 80 includes a processor that executes various processes, a memory, and the like. The memory is composed of one or a plurality of storage media such as a ROM (Read Only Memory) and a RAM (Random Access Memory) depending on the application. In addition to the control program for the grinding apparatus 1, the memory stores a determination program for determining whether the workpiece W is turned upside down.

  In such a grinding apparatus 1, the workpiece W is transported from the cassette C to the positioning mechanism 20, and the workpiece W is centered by the positioning mechanism 20. Next, the workpiece W is loaded onto the chuck table 41, and the workpiece W is positioned in the order of the loading position, rough grinding position, finish grinding position, and unloading position by the rotation of the turntable 40. The workpiece W is roughly ground at the rough grinding position, and the workpiece W is finish ground at the finish grinding position. Then, the processed workpiece W is unloaded from the chuck table 41, and the workpiece W is cleaned by the cleaning mechanism 25 and stored in the cassette C.

  By the way, there is a case where the workpiece W is stored in the cassette C in a state where the front and back sides of the workpiece W are reversed and the workpiece W is placed with the protective tape T facing the chuck table 41. is there. For this reason, it is required to detect the front and back of the workpiece W before the workpiece W is placed on the chuck table 41. Since the protective tape T is attached to the surface of the workpiece W, the presence or absence of the protective tape T on the surface side of the workpiece W is detected by a color sensor or the like to determine the front and back of the workpiece W. Is possible. However, not all the protective tapes T can be detected, and it is impossible to detect the presence or absence of a protective tape T that is not colored like a transparent tape.

  Although it is difficult to visually distinguish the front and back of the workpiece W, the surface is a smooth resin surface, while the back surface is a satin-like silicon surface. Therefore, paying attention to the difference in material and surface state between the front and back surfaces of the workpiece W, the front and back surfaces of the workpiece W, which are difficult to discriminate visually, are determined based on the difference in wettability. In the present embodiment, the front / back detection means 70 is provided near the position table 21 of the grinding apparatus 1, and the droplet D is dropped from the front / back detection means 70 onto the workpiece W on the position table 21. Then, the front and back of the workpiece W are determined from the degree of spreading (swelling) of the droplets according to the wettability of the front and back of the workpiece W.

  The front / back detection means and the method for determining the front / back of the workpiece will be described below with reference to FIGS. FIG. 2 is a schematic diagram of the front / back detection means of the present embodiment. FIG. 3 is an explanatory diagram of the front / back determination processing of the workpiece according to the present embodiment. The front / back detection means and the method for determining the front / back of the workpiece are not limited to the contents shown in FIGS. 2 and 3 and can be changed as appropriate.

  As shown in FIG. 2, in the vicinity of the position table 21, the front / back detection means 70 detects the front and back of the workpiece W before the workpiece W is placed on the chuck table 41 (see FIG. 1). Is arranged. The front / back detection means 70 drops the droplet D onto the upper surface of the workpiece W placed on the horizontal holding surface of the position table 21, and the surface 85 on which the protective tape T is adhered due to the difference in wettability between the front and back sides. The back surface 86 to be ground is detected. The front / back detection unit 70 is provided with a droplet dropping unit 71 that drops a predetermined amount of droplet D on the upper surface of the workpiece W and an imaging unit 75 that images the droplet D on the upper surface of the workpiece W. The front and back of the workpiece W are determined by comparing the captured image and the reference image information.

  The droplet dropping unit 71 is configured by attaching a drip-type nozzle 73 to the tip of the pipe 72, and is positioned above the workpiece W by the turning of the pipe 72. When the nozzle 73 is positioned at a predetermined position, a predetermined amount of droplets D are dropped from the nozzle 73 onto the upper surface of the workpiece W. The imaging unit 75 is attached to the tip of the support member 76 with the optical axis slightly tilted with respect to the vertical direction, and is positioned above the workpiece W by the turning of the support member 76. When the imaging unit 75 is positioned above the droplet D, the imaging unit 75 images the droplet D on the workpiece W from obliquely above.

  A reference image information storage unit 81 and a determination unit 82 of the control unit 80 are connected to the imaging unit 75, and a captured image is output from the imaging unit 75 to the reference image information storage unit 81 and the determination unit 82. In the reference image information storage unit 81, the droplet D captured by the imaging unit 75 when the droplet D is appropriately applied from the droplet dropping unit 71 to the front surface 85 and / or the back surface 86 of the workpiece W in advance. The captured image is stored as reference image information. That is, the reference image information includes a captured image of the droplet D dropped on the tape surface of the protective tape T, which is the surface 85 of the workpiece W, and a back surface 86 of the workpiece W as a template image for the matching process. A captured image of a droplet D dropped on a certain silicon surface is used.

  The determination unit 82 compares the captured image input from the imaging unit 75 with the reference image information stored in advance in the reference image information storage unit 81. In this case, matching processing between the captured image and the reference image information is performed, and the front surface 85 and the back surface 86 of the workpiece W are determined based on the similarity calculated in the matching processing. When the similarity between the captured image and the reference image information is high, it is determined that the upper surface of the workpiece W in the captured image is the same as the surface on which the droplet D is dropped with the reference image information. When the similarity between the captured image and the reference image information is low, it is determined that the upper surface in the captured image is different from the surface on which the droplet D is dropped with the reference image information.

  3A, since the back surface 86 of the workpiece W is a satin-like silicon surface, the droplet D dropped on the back surface 86 of the workpiece W due to hydrophilicity is It has spread. On the other hand, as shown in the right figure of FIG. 3A, since the surface 85 of the workpiece W is a smooth tape surface of the protective tape T, the droplet D dropped on the surface 85 of the workpiece W due to water repellency. Is exciting without spreading. At least one of these captured images is stored in advance as reference image information, and the front and back of the workpiece W onto which the droplet D has been dropped is determined by comparing the reference image information with the subsequent captured image. .

  For example, as shown in FIG. 3B, an image of a droplet D dropped on the back surface 86 of the workpiece W is stored as reference image information. The droplet D of the reference image information spreads thinly, and if the droplet D that spreads thinly is captured in the current captured image, the similarity is increased in the matching process between the reference image information and the captured image. For this reason, it is determined that the upper surface of the workpiece W in the current captured image is the back surface 86 of the workpiece W with the satin-like silicon surface exposed. Thus, a captured image having a high degree of similarity to the reference image information is determined to be the back surface 86 of the workpiece W that is the same as the reference captured image.

  Further, as shown in FIG. 3C, an image of a droplet D dropped on the back surface 86 of the workpiece W is stored as reference image information. The droplet D of the reference image information spreads thinly, and when the droplet D that has risen small is captured in the current captured image, the similarity is lowered in the matching process between the reference image information and the captured image. For this reason, it is determined that the upper surface of the workpiece W in the current captured image is the surface 85 of the workpiece W from which the tape surface of the protective tape T is exposed. As described above, the captured image having a low similarity to the reference image information is determined to be the surface 85 of the workpiece W different from the reference captured image.

  It is also possible to store, as reference image information, an image of the droplet D dropped onto the surface 85 of the workpiece W and rising without spreading on the surface 85 (see the right figure in FIG. 3A). In this case, the captured image having a low similarity to the reference image information is determined to be the back surface 86 of the workpiece W different from the reference image information. A captured image having a high similarity to the reference image information is determined to be the same surface 85 of the workpiece W as the reference image information. It is also possible to store images of the droplets D dropped on both the front surface 85 and the back surface 86 of the workpiece W as reference image information. Of course, when the reference image information is stored, the droplet D on the workpiece W is imaged under the same conditions as in the subsequent imaging.

  Note that the determination unit 82 (see FIG. 2) only has to determine the front and back of the workpiece W by comparing the reference image information and the captured image, and is not limited to the method of determining the front and back of the workpiece W by matching processing. . For example, the front and back of the workpiece W may be determined by comparing the area of the droplet D of the reference image information with the area of the droplet D of the captured image. When the area difference between the reference image information and the droplet D of the captured image is smaller than a predetermined value, the upper surface of the workpiece W in the captured image is the same as the surface on which the droplet D is dropped with the reference image information. It is judged. When the area difference between the reference image information and the droplet D of the captured image is equal to or greater than a predetermined value, it is determined that the upper surface of the workpiece W of the captured image is different from the surface on which the droplet is dropped with the reference image information. .

  Further, the determination unit 82 (see FIG. 2) may determine the front and back of the workpiece W based on the difference image between the reference image information and the captured image. When the total luminance of each pixel of the difference image is smaller than a predetermined value, it is determined that the upper surface of the workpiece W in the captured image is the same as the surface on which the droplet D is dropped with the reference image information. . When the total luminance of each pixel of the difference image is equal to or larger than a predetermined value, it is determined that the upper surface of the workpiece W in the captured image is different from the surface on which the droplet D is dropped with the reference image information. In addition, as the threshold value for judging the front and back from the similarity, the area difference, and the brightness, values obtained experimentally, empirically, or theoretically are used.

  Although details are omitted, in the determination processing of the workpiece W by the determination unit 82 (see FIG. 2), various image processing such as binarization processing may be performed to compare the reference image information and the captured image. Also, as the reference image information, only the feature points indicating the image of the droplet D, not the image of the droplet D, are extracted and stored in the reference image information storage unit 81 (see FIG. 2). And the feature point of the captured image may be compared. Furthermore, the front and back of the workpiece W are determined by learning the droplet D dropped on the surface 85 of the workpiece W and the droplet D dropped on the back surface 86 by deep learning without having the reference image information. You may make it do.

  With reference to FIG. 4, the detection operation by the front and back detection means will be described. FIG. 4 is an explanatory diagram of the detection operation of the front / back detection means of the present embodiment.

  As shown in FIG. 4A, when the workpiece W is conveyed from the cassette C (see FIG. 1) onto the position table 21, the positioning mechanism 20 (see FIG. 1) places the workpiece W on the center of the position table 21. The center is adjusted. Further, the nozzle 73 of the droplet dropping unit 71 is positioned above the workpiece W, and the droplet D is dropped from the droplet dropping unit 71 by a predetermined amount onto the upper surface of the workpiece W, so that the workpiece W A droplet D (liquid reservoir) adheres to a predetermined position on the upper surface. At this time, the wettability of the upper surface of the workpiece W varies depending on the surface state and the material, and the spread and rise of the droplets D change depending on the wettability.

  Next, as shown in FIG. 4B, the imaging unit 75 is positioned above the workpiece W, and the imaging unit 75 images the droplet D on the upper surface of the workpiece W. At this time, since the optical axis of the imaging unit 75 is slightly inclined with respect to the vertical direction, not only the degree of spreading of the droplet D but also the degree of swelling of the droplet D is imaged from an oblique direction. Then, by comparing the droplet D of the captured image captured by the imaging unit 75 with the droplet D stored in advance as reference image information, whether the upper surface of the workpiece W is the front surface 85 or the rear surface 86. Is judged. In the example of the figure, the droplet D spreads thinly on the upper surface of the workpiece W, and it is determined that the upper surface of the workpiece W is the back surface 86.

  As described above, according to the grinding apparatus 1 of the present embodiment, when the droplet D is dropped on the workpiece W, the droplet D is formed on the surface 85 of the workpiece W due to the water repellency of the protective tape T. It swells without spreading, and on the back surface 86 of the workpiece W, the droplets D spread out to form a film due to hydrophilicity. By utilizing the difference in wettability of the workpiece W, the surface 85 of the workpiece W to which the protective tape T is adhered or the back surface of the workpiece W to which the protective tape T is not adhered is used. 86 can be accurately detected, and processing defects due to the reverse of the workpiece W can be reliably prevented.

  In the present embodiment, the front and back detection means may be configured to detect the front and back of the workpiece using the difference in wettability of the droplets on the upper surface of the workpiece, and the detection method is particularly limited. Not.

  In the present embodiment, the droplet on the upper surface of the workpiece is imaged obliquely from above by the imaging unit. However, the present invention is not limited to this configuration. The droplet on the upper surface of the workpiece may be imaged from directly above by the imaging unit.

  Further, in the present embodiment, the configuration in which the drip-type nozzle is provided as the droplet dropping unit is illustrated, but the configuration is not limited thereto. The droplet dropping unit may be configured in any way as long as it can drop a predetermined amount of droplets onto the workpiece. The droplets may be any liquid that can be dropped onto the workpiece, such as distilled water.

  Moreover, in this Embodiment, although it was set as the structure by which the front and back of a to-be-processed object is judged by the front and back detection means on a position table, it is not limited to this structure. The front / back detection means only needs to detect the front / back of the workpiece before being placed on the chuck table. For example, the front / back detection means determines the front / back of the workpiece during conveyance of the workpiece by the cassette robot. May be.

  Further, in the present embodiment, the grinding apparatus that grinds the workpiece is exemplified as the processing apparatus, but the present invention is not limited to this configuration. The present invention is applicable to other processing apparatuses provided with front and back detection means. For example, a cutting device, a polishing device, a laser processing device, a plasma etching device, an edge trimming device, an expanding device, a braking device can be used as long as the processing device can detect front and back surfaces using the wettability of droplets on the upper surface of the workpiece. You may apply to other processing apparatuses, such as an apparatus and the cluster apparatus which combined these. In particular, in the case of a trimming apparatus, it is possible to image a droplet on a workpiece using an existing imaging unit. Therefore, the processing means is not limited to the grinding wheel, but may be a cutting blade, a polishing pad, a laser processing head, an expansion drum, a braking blade, or the like.

  In addition, depending on the type of processing, the workpiece to be processed, for example, semiconductor device wafer, optical device wafer, package substrate, semiconductor substrate, inorganic material substrate, oxide wafer, raw ceramic substrate, piezoelectric substrate, etc. A workpiece may be used. As the semiconductor device wafer, a silicon wafer or a compound semiconductor wafer after device formation may be used. As the optical device wafer, a sapphire wafer or silicon carbide wafer after device formation may be used. Further, a CSP (Chip Size Package) substrate may be used as the package substrate, silicon or gallium arsenide may be used as the semiconductor substrate, and sapphire, ceramics, glass, or the like may be used as the inorganic material substrate. Furthermore, as the oxide wafer, lithium tantalate or lithium niobate after device formation or before device formation may be used.

  Moreover, in this Embodiment, although the protective tape for grinding was illustrated on the surface of the workpiece, it is not limited to this structure. The protective tape can be appropriately changed according to the type of the processing apparatus. For example, when the processing apparatus is a cutting apparatus or an edge trimming apparatus, a dicing tape may be used as the protective tape.

  In the present embodiment, the chuck table is not limited to the suction chuck table, and may be an electrostatic chuck table.

  Moreover, although this Embodiment and the modified example were demonstrated, what combined the said embodiment and modified example entirely or partially as another embodiment of this invention may be sufficient.

  The embodiments of the present invention are not limited to the above-described embodiments, and various changes, substitutions, and modifications may be made without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by technological advancement or another derived technique, the method may be used. Accordingly, the claims cover all embodiments that can be included within the scope of the technical idea of the present invention.

  Further, in the present embodiment, the configuration in which the present invention is applied to the cutting apparatus has been described. However, the present invention is applied to other apparatuses capable of determining the front and back of the workpiece by the difference in wettability between the front and back surfaces of the workpiece. It is also possible to do.

  As described above, the present invention has an effect that it is possible to reliably detect the reverse of the workpiece, and in particular, to a processing apparatus for processing a workpiece having a protective tape attached to the surface. Useful.

1 Grinding equipment (processing equipment)
41 Chuck table 56 Coarse grinding means (processing means)
66 Finish grinding means (processing means)
70 Front / Back Detection Means 71 Droplet Dropping Unit 73 Nozzle 75 Imaging Unit 81 Reference Image Information Storage Unit 82 Judgment Unit 85 Surface of Workpiece 86 Backside of Workpiece D Water Drop T Protective Tape W Workpiece

Claims (2)

A processing apparatus including at least a chuck table for holding a workpiece having a protective tape attached to a surface, and a processing means for processing the back surface of the workpiece held on the chuck table,
Front and back detection means for detecting the front and back of the workpiece before the workpiece is placed on the chuck table is provided,
The front / back detection means determines whether the surface on which the droplets are dropped due to the difference in wettability of the droplets dropped on the upper surface of the workpiece placed on the horizontal holding surface is the surface on which the protective tape is applied or the back surface to be processed. A processing apparatus characterized by detecting the above. The front and back detection means includes a droplet dropping unit that drops a predetermined amount of droplets, an imaging unit that images a droplet dropped from the droplet dropping unit onto the upper surface of the workpiece, A reference image information storage unit that images a droplet dropped from the droplet dropping unit on the back surface by the imaging unit and stores it as reference image information;
The processing apparatus according to claim 1, further comprising: a determination unit configured to determine that the surface on which the droplet is dropped is the front surface or the back surface as compared with the reference image information.

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