JP2013122956A - Processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing device which allows a user to observe the state of a workpiece during processing.SOLUTION: A processing device includes: a chuck table rotatably holding a workpiece; processing means having a processing wheel which contacts with the workpiece so as to cover a part of the workpiece held by the chuck table and processes the workpiece while rotating with an exposed part formed in the workpiece; a processing chamber cover which covers at least the chuck table and the processing wheel and defines a processing chamber; a pipe member connecting with an opening formed at the processing chamber cover at one end and having a predetermined length; imaging means disposed at the other end side of the pipe member and capturing an image of the exposed part of the workpiece through the pipe member during processing; and an optical fiber where one end connects with a light source and the other end penetrates through the processing chamber cover and lights the exposed part disposed in the processing chamber.

Description

  The present invention relates to a processing apparatus provided with a processing wheel for processing a workpiece.

  In the manufacturing process of an optical device, a light emitting diode (LED) or laser diode (LD) is formed in each region partitioned by a plurality of division lines formed in a lattice pattern on the surface of a crystal growth substrate such as a sapphire substrate or a silicon carbide substrate. ) And the like to form an optical device wafer.

  Thereafter, the crystal growth substrate side of the optical device wafer is ground by a grinding device to be thinned to a predetermined thickness, and polished by a polishing device to remove grinding distortion. Furthermore, after forming an electrode, it divides | segments along a division | segmentation scheduled line, and each optical device chip | tip is manufactured.

  While a workpiece such as a sapphire substrate is being processed by a grinding device or a polishing device, if the workpiece is damaged, the entire workpiece becomes defective and a large number of devices are lost. Therefore, there is a demand for a processing apparatus that can observe the state of the workpiece being processed in order to detect a slight abnormality occurring in the workpiece before the workpiece is damaged.

JP 2004-74382 A

  Usually, in these processing devices, processing is performed while supplying the processing fluid to the processing point, and a processing chamber cover that covers the processing point and defines the processing chamber is provided to prevent the processing fluid from splashing into the processing device. Have.

  If an image pickup means for observing the state of the workpiece is disposed in the inside of the processing chamber, there is a problem that the processing liquid adheres to the image pickup means and the image cannot be taken. On the other hand, there is a problem that even if the processing chamber cover is made transparent and an image is taken by the imaging means through the cover, the processing liquid adheres to the cover and imaging cannot be performed. In particular, with continuous machining, the frequency of occurrence of problems due to these machining fluids increases.

  This invention is made | formed in view of such a point, The place made into the objective is providing the processing apparatus which can observe the state of the to-be-processed object in process.

  According to the present invention, there is provided a machining apparatus, a chuck table that rotatably holds a workpiece, and a workpiece that is in contact with the workpiece so as to cover a part of the workpiece held on the chuck table. A processing means having a processing wheel for processing a workpiece while rotating in a state where an exposed portion is formed on the object, a processing chamber cover for covering at least the chuck table and the processing wheel and defining a processing chamber, and one end A pipe member having a predetermined length connected to an opening formed in the processing chamber cover, and disposed on the other end side of the pipe member, and the workpiece is exposed through the pipe member during processing. And an optical fiber that illuminates the exposed portion that is connected to the light source and penetrates the processing chamber cover and has the other end disposed in the processing chamber. A processing apparatus is provided.

  Preferably, the imaging means is composed of a high speed camera. Preferably, the imaging unit images an exposed part of the workpiece to form a captured image, and the processing apparatus further includes a control unit having a detection unit that detects an abnormality occurring in the workpiece based on the captured image. Yes.

  According to the present invention, since the exposed portion of the workpiece illuminated through the pipe member having a predetermined length is imaged by the imaging means, the imaging is not hindered by the machining liquid even during continuous machining. It is possible to observe the state of the workpiece inside by taking an image with an imaging means.

It is a perspective view of a grinding device in the state where a processing chamber cover was removed. 1 is a perspective view of a grinding apparatus according to an embodiment of the present invention. It is a disassembled perspective view of the state which affixes a protective tape on the surface of an optical device wafer. It is a perspective view of an illumination unit. It is a partial cross section side view in grinding the back surface of an optical device wafer.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a perspective view of the grinding apparatus 2 according to the embodiment of the present invention with a processing cover removed is shown. FIG. 2 is a perspective view of a state in which the processing cover is mounted. Reference numeral 4 denotes a base of the grinding apparatus 2, and a column 6 is erected on the rear side of the base 4. Two pairs of guide rails 8 and 36 extending in the vertical direction are fixed to the column 6.

  A rough grinding unit 10 is mounted along a pair of guide rails 8 so as to be movable in the vertical direction. The rough grinding unit 10 is attached to a moving base 12 whose housing 14 moves in the vertical direction along a pair of guide rails 8 via a support member 28.

  The rough grinding unit 10 includes a housing 14, a spindle 16 rotatably accommodated in the housing 14, a wheel mount 18 fixed to the tip of the spindle 16, a servo motor 20 that rotationally drives the spindle 16, and a wheel mount. And a rough grinding wheel 22 which is detachably attached to 18. The rough grinding wheel 22 is composed of a wheel base 24 and a plurality of grinding wheels 26 for rough grinding fixed to the free end of the wheel base 24 in an annular shape.

  The rough grinding unit 10 includes a rough grinding unit feed mechanism 34 including a ball screw 30 and a pulse motor 32 that move the rough grinding unit 10 up and down along a pair of guide rails 8. When the pulse motor 32 is pulse-driven, the ball screw 30 rotates and the moving base 12 is moved in the vertical direction.

  A finish grinding unit 38 is mounted so as to be movable in the vertical direction along another pair of rails 36 fixed to the column 6. The finish grinding unit 38 is attached to a moving base 40 whose housing 42 moves in a vertical direction along a pair of guide rails 36 via a support member 43.

  The finish grinding unit 38 includes a housing 42, a spindle 44 rotatably accommodated in the housing 42, a wheel mount 46 fixed to the tip of the spindle 44, a servo motor 48 that rotationally drives the spindle 44, and a wheel mount 46 and a finish grinding wheel 50 detachably attached to 46. The finish grinding wheel 50 includes an annular base 52 and a plurality of grinding wheels 54 for finish grinding that are annularly fixed to the free ends of the annular base 52.

  The finish grinding unit 38 includes a finish grinding unit feed mechanism 60 including a ball screw 56 and a pulse motor 58 that move the finish grinding unit 38 in the vertical direction along the pair of guide rails 36. When the pulse motor 58 is driven, the ball screw 56 rotates and the finish grinding unit 38 is moved in the vertical direction.

  The grinding device 2 includes a turntable 62 disposed so as to be substantially flush with the upper surface of the base 4 on the front side of the column 6. The turntable 62 is formed in a relatively large-diameter disk shape, and is rotated in a direction indicated by an arrow a by a rotation driving mechanism (not shown).

  On the turntable 62, three chuck tables 64 are arranged so as to be rotatable in a horizontal plane, spaced from each other by 120 degrees in the circumferential direction. The chuck table 64 has a suction holding unit made of porous ceramics or the like, and sucks and holds the wafer placed on the holding surface of the suction holding unit by operating a negative pressure suction unit.

  The three chuck tables 64 arranged on the turntable 62 rotate the turntable 62 appropriately so that the wafer loading / unloading area A, the rough grinding area B, the finish grinding area C, and the wafer loading / unloading are performed. The region A is sequentially moved.

  In the front portion of the base 4, a cassette 66 containing a wafer before grinding, a wafer transfer robot 72 having a hand 68 and a link mechanism 70, a positioning table 74 having a plurality of positioning pins 76, and a wafer carry-in mechanism (loading) Arm) 78, a wafer unloading mechanism (unloading arm) 80, a spinner cleaning device 82 that cleans and spin-drys the ground wafer, and a ground wafer that has been cleaned and spin-dried by spinner cleaning device 82. A cassette 86 is provided.

  The spinner cleaning device 82 includes a spinner table 84 having a diameter smaller than that of a wafer that rotates while sucking and holding the ground wafer. A control panel 88 for inputting instructions to the apparatus such as grinding conditions is disposed near the front end of the base 4.

  Reference numeral 90 denotes a processing chamber 91 that covers the rough grinding wheel 22, the chuck table 64 positioned in the rough grinding region B, the finish grinding wheel 50, and the chuck table 64 positioned in the finish grinding region C. A processing chamber cover to be defined and mounted on the base 4 as shown in FIG.

  The processing chamber cover 90 has an annular insertion portion 92 into which the housing 14 of the rough grinding unit 10 is inserted, and an annular insertion portion 94 into which the housing 42 of the finish grinding unit 38 is inserted. The processing chamber cover 90 further has pipe mounting holes 96 and 98 in which the ends of the pipes are mounted, and lighting unit mounting holes 100 and 102 in which the lighting units 125 and 135 are mounted.

  As shown in FIGS. 2 and 5, one end of the pipe 104 is attached to the pipe attachment hole 96 via the bellows 106. The other end of the pipe 104 is connected to an image pickup unit 108 composed of a high speed camera or the like. The imaging unit 108 is attached to a support member 110 fixed to the base 4. The pipe 104 preferably has a predetermined length or more, for example, a length of 20 cm or more. This predetermined length is a distance away from the processing point to the extent that the grinding water does not scatter.

  Similarly, one end of the pipe 112 is attached to the pipe attachment hole 98 via the bellows 114, and the other end of the pipe 112 is connected to the imaging unit 116 constituted by a high-speed camera or the like. The imaging unit 116 is attached to a support member 118 fixed to the base 4.

  Referring to FIG. 4, a perspective view of the lighting unit 125 is shown. The lighting unit 125 includes a mounting plate 120 that is detachably mounted in the lighting unit mounting hole 100, a flexible cord 122 that is inserted into an insertion hole formed in the mounting plate 120, and an optical fiber that is inserted into the flexible cord 122. 128 and a light source 130 connected to an optical fiber 128.

  Preferably, the light source 130 comprises a light emitting diode (LED) and the optical fiber 128 comprises a plastic optical fiber. The tip of the optical fiber 128 extends to the tip 122 a of the flexible cord 122. The flexible cord 122 is movably fixed to the mounting plate 120 by a cord fixing portion 124 such as an O-ring. The mounting plate 120 has a handle 126.

  The illumination unit 135 is configured similarly to the illumination unit 125, and includes a mounting plate 132 and a pair of flexible cords 134 inserted into the mounting plate 132. As shown in FIG. 2, an optical fiber 136 is inserted in the flexible cord 134, and one end of the optical fiber 136 is connected to a light source 138 such as an LED.

  Referring to FIG. 3, an exploded perspective view showing a state where the protective tape 21 is stuck on the surface 11 a of the optical device wafer 11 is shown. The optical device wafer 11 is configured by laminating an epitaxial layer 15 such as gallium nitride (GaN) on a sapphire substrate 13. The optical device wafer 11 has a front surface 11a on which an epitaxial layer 15 is stacked and a back surface 11b on which the sapphire substrate 13 is exposed.

  The sapphire substrate 13 has a thickness of 1.3 mm, for example, and the epitaxial layer 15 has a thickness of 5 μm, for example. A plurality of optical devices 19 such as LEDs are formed in the epitaxial layer 15 by being partitioned by division lines (streets) 17 formed in a lattice pattern.

  In order to grind the back surface 11b made of the sapphire substrate 13 of the optical device wafer 11, a protective tape 21 is attached to the front surface 11a of the optical device wafer 11, and the protective tape 21 side is sucked and held by the chuck table 64, The back surface 11b of the device wafer 11 is exposed.

  Next, the operation of the grinding apparatus 2 of the present invention will be described with reference to FIG. FIG. 5 shows a state in which the optical device wafer 11 whose rough grinding has been finished by the rough grinding unit 10 is finish ground by the finish grinding unit 38.

  After the rough grinding is finished, the turntable 62 is rotated 120 degrees counterclockwise, whereby the chuck table 64 holding the optical device wafer 11 is positioned in the rough grinding region B.

  While rotating the chuck table 64 in the direction of arrow a, for example, at 300 rpm with respect to the optical device wafer 11 thus positioned, the finish grinding wheel 50 is rotated in the direction of arrow b, for example, at 1000 rpm, and a finish grinding unit feed mechanism. 60 is operated to bring the grinding wheel 54 for finish grinding into contact with the back surface 11 b of the optical device wafer 11.

  The finish grinding wheel 38 is then ground and fed by a predetermined amount at a predetermined grinding feed speed, and finish grinding of the back surface 11b of the optical device wafer 11 is performed. The optical device wafer 11 is finished to a desired thickness while measuring the thickness of the optical device wafer 11 with a contact-type or non-contact-type thickness measurement gauge. At the time of finish grinding, grinding of the back surface 11b of the optical device wafer 11 is performed while supplying a grinding fluid (processing fluid) such as pure water.

  During this finish grinding, the exposed portion of the back surface 11b of the optical device wafer 11 is imaged by the imaging unit 108 via the pipe 104 while illuminating the processing area by the optical fiber 128 inserted into the flexible cord 122. Finish grinding while forming an image.

  The imaging unit 108 is connected to a controller (not shown) having a detection unit that detects an abnormality that has occurred in the optical device wafer 11 based on the captured image, and when this detection unit detects an abnormality such as a crack in the optical device wafer 11. In this case, a buzzer or a red lamp or the like is lit to notify the operator of the grinding apparatus 2 of the abnormality of the workpiece.

  Further, by connecting the imaging unit 108 to a display monitor (not shown), a captured image during grinding is displayed on the display monitor so that the operator can observe the state of the optical device wafer 11 during grinding. Also good.

  In the present embodiment, the exposed portion of the optical device wafer 11 is imaged by the imaging unit 108 via the pipe 104 while illuminating the imaging area of the processing chamber 91 with the optical fiber 128. There is nothing to do.

  Preferably, the imaging unit 108 is composed of a high speed camera. By adopting a high-speed camera as the imaging unit 108, a still image of the optical device wafer 11 rotating at high speed during grinding can be obtained.

  Since the bellows 106 is attached to the tip of the pipe 104, it is possible to ensure flexible attachment of the pipe 104 to the processing chamber cover 90. A bellows may be provided also on the imaging unit 108 side of the pipe 104.

  Further, since the optical fiber 128 is inserted into the flexible cord 122 so that the tip of the optical fiber 128 reaches the tip 122a of the flexible cord 122, the tip of the optical fiber 128 is placed at an optimal illumination position by bending the flexible cord 122 by hand. Can be positioned.

  Since the flexible cord 122 is movably fixed to the mounting plate 120 by the fixing portion 124, the length of the flexible cord 122 inserted into the processing chamber 91 can be freely adjusted.

  In the description with reference to FIG. 5, the illumination by the illumination unit 125 during finish grinding by the finish grinding unit 38 and the imaging by the imaging unit 108 through the pipe 104 have been described, but also during the rough grinding by the coarse grinding unit 10, Similar illumination and imaging can be performed.

  In this case, the exposed portion of the optical device wafer 11 is imaged by the imaging unit 116 via the pipe 112 while illuminating the exposed portion of the optical device wafer 11 by the illumination unit 135. Preferably, the imaging unit 116 is also composed of a high speed camera. Like the pipe 104, the pipe 112 preferably has a predetermined length or more, for example, 20 cm or more.

  In the embodiment described above, an example in which the optical device wafer 11 is employed as a workpiece has been described. However, the workpiece is not limited to the optical device wafer 11, and the present invention is applied to other wafers such as a silicon wafer. Can be applied similarly.

  In the above-described embodiment, the example in which the present invention is applied to the grinding apparatus 2 has been described. However, the present invention is not limited to the grinding apparatus. For example, a part of the workpiece is covered with a polishing pad. The present invention can also be applied to a dry polish type polishing apparatus for polishing a workpiece. In this case, the grinding wheel becomes the processing wheel.

2 Grinding device 10 Rough grinding unit 11 Optical device wafer 13 Sapphire substrate 22 Rough grinding wheel 38 Finish grinding unit 50 Finish grinding wheel 90 Processing chamber cover 91 Processing chamber 104, 112 Pipe 108, 116 Imaging unit (high speed camera)
122,134 Flexible cord 128,136 Optical fiber

Claims (3)

A processing device,
A chuck table that rotatably holds the workpiece;
Processing means having a processing wheel for processing a workpiece while rotating in a state where an exposed portion is formed on the workpiece by contacting the workpiece so as to cover a part of the workpiece held on the chuck table When,
A processing chamber cover that at least covers the chuck table and the processing wheel to define a processing chamber;
A pipe member having a predetermined length, one end of which is connected to an opening formed in the processing chamber cover;
An imaging means disposed on the other end side of the pipe member and imaging the exposed portion of the workpiece through the pipe member during processing;
An optical fiber having one end connected to a light source and penetrating the processing chamber cover and the other end illuminating the exposed portion disposed in the processing chamber;
A processing apparatus comprising:   The processing apparatus according to claim 1, wherein the imaging means is constituted by a high-speed camera. The imaging means images the exposed portion of the workpiece to form a captured image;
The processing apparatus according to claim 1, further comprising a control unit having a detection unit that detects an abnormality that has occurred in the workpiece based on the captured image.

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