JP2010005717A - Machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machining apparatus for checking an outer circumference state of a processed object ground or polished. <P>SOLUTION: This machining apparatus has a chuck table holding a processed object, a machining means grinding or polishing a back surface of the processed object held by the chuck table to the desired thickness, a spinner cleaning device performing cleaning and spin-dry of the processed object ground or polished, and a control means controlling the spinner cleaning device. The spinner cleaning device includes a spinner table having a diameter roughly equal to or larger than the processed object and turning while holding the processed object, a cleaning fluid supply nozzle supplying cleaning fluid to the processed object, and a photographing means disposed upper than a processed object holding surface of the spinner table and having an illumination means detecting damage by photographing an outer circumference part of the processed object for which cleaning and spin-dry are performed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a processing apparatus for grinding or polishing a workpiece such as a semiconductor wafer.

  A semiconductor wafer in which devices such as IC and LSI are formed on the surface, and each device is defined by lines to be divided is ground or polished by a grinding / polishing device and processed to a desired thickness, and then a dicing device or the like The line to be divided is cut and divided into individual devices, and the divided devices are widely used in electric devices such as mobile phones and personal computers.

In recent years, in order to achieve weight reduction and miniaturization of electrical equipment, it has been required to grind these workpieces such as semiconductor wafers very thinly to 100 μm or less and further to 50 μm or less, for example.
JP 2006-21264 A

  However, it is difficult to grind or polish the workpiece very thinly to 100 μm or less, and further to 50 μm or less. Especially in the case of semiconductor wafers, the outer peripheral cross-sectional shape is R-shaped. The portion has a sharp shape, the edge portion may flutter during grinding, and damage such as chipping or cracking may occur on the outer periphery of the semiconductor wafer.

  Therefore, after the grinding or polishing of the outer periphery of the semiconductor wafer is separately inspected with an inspection apparatus to confirm the presence or absence of damage, the semiconductor wafer in which no damage has occurred may be sent to a subsequent process.

  However, thinly formed workpieces such as semiconductor wafers are easily damaged, and are damaged by grinding or polishing with a grinding / polishing device and then transported to a separate inspection device and placed on a table of the inspection device. There is a problem of end up.

  This invention is made | formed in view of such a point, The place made into the objective is providing the processing apparatus which can confirm the state of the outer peripheral part of the workpiece ground or grind | polished.

  According to the first aspect of the present invention, the chuck table for holding the workpiece, the processing means for grinding or polishing the back surface of the workpiece held on the chuck table to a desired thickness, and the ground or polished workpiece. A processing apparatus comprising a spinner cleaning apparatus for cleaning and spin-drying a workpiece, and a control means for controlling the spinner cleaning apparatus, wherein the spinner cleaning apparatus has a diameter approximately equal to or greater than that of a workpiece. A spinner table that rotates while holding a workpiece, a cleaning water supply nozzle that supplies cleaning water to the workpiece, and a workpiece holding surface of the spinner table that are disposed above the workpiece holding surface, cleaned and spin-dried. There is provided a processing apparatus comprising: an imaging unit including an illuminating unit that detects a breakage by imaging an outer peripheral portion of a workpiece.

  According to a second aspect of the present invention, in the first aspect of the present invention, a storage cassette for storing a workpiece after an outer peripheral portion has been imaged by the imaging means, and a workpiece on the spinner table are accommodated. Loading means for carrying in the cassette, wherein the storage cassette has a plurality of workpiece storage portions for storing the workpiece, and the control means detects the breakage of the workpiece detected by the imaging means. There is provided a processing apparatus characterized by having a storage unit that stores information and stores a position of the workpiece storage unit in which a workpiece having damage information is stored.

  According to the first aspect of the present invention, since the outer periphery of the workpiece that has been ground or polished, cleaned and spin-dried is imaged by the imaging means, whether or not the outer periphery of each workpiece is damaged on the spinner table. Therefore, there is no need to use a separate inspection device, and the number of processes can be reduced. In addition, since the workpiece does not move, damage during handling can be prevented.

  According to the invention described in claim 2, since the damage information of each workpiece and the workpiece accommodation position of the accommodation cassette in which the workpiece is accommodated are stored in the control means in correspondence with each other, a plurality of workpieces After finishing this grinding, it is possible to determine in which position of the storage cassette the damaged workpiece is stored, and it is possible to easily detect which is the damaged workpiece.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a semiconductor wafer 11 before being processed to a predetermined thickness. The semiconductor wafer 11 shown in FIG. 1 is made of, for example, a silicon wafer having a thickness of 700 μm, and a plurality of streets 13 are formed in a lattice shape on the surface 11a, and a plurality of streets partitioned by the plurality of streets 13 are formed. A device 15 such as an IC or LSI is formed in the region.

  The semiconductor wafer 11 configured as described above includes a device region 17 in which the device 15 is formed, and an outer peripheral surplus region 19 that surrounds the device region 17. A notch 21 is formed on the outer periphery of the semiconductor wafer 11 as a mark indicating the crystal orientation of the silicon wafer. The direction of the notch 21 is parallel to the street 13.

  A protective tape 23 is attached to the surface 11a of the semiconductor wafer 11 by a protective tape attaching process. Therefore, when the semiconductor wafer 11 is ground, the front surface 11a of the semiconductor wafer 11 is protected by the protective tape 23, and the back surface 11b is exposed as shown in FIG.

  Hereinafter, a grinding apparatus 2 for grinding the back surface 11b of the semiconductor wafer 11 thus formed to a predetermined thickness will be described with reference to FIG. Reference numeral 4 denotes a housing of the grinding apparatus 2, and two columns 6 a 6 b are erected vertically at the rear of the housing 4.

  A pair of guide rails (only one is shown) 8 extending in the vertical direction is fixed to the column 6a. A rough grinding unit 10 is mounted along the 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 20 moves up and down along a pair of guide rails 8.

  The rough grinding unit 10 includes a housing 20, a spindle (not shown) rotatably accommodated in the housing 20, a servo motor 22 that rotationally drives the spindle, and a plurality of rough grinding grinding wheels fixed to the tip of the spindle. A grinding wheel 24 having 26 is included.

  The rough grinding unit 10 includes a rough grinding unit moving mechanism 18 including a ball screw 14 and a pulse motor 16 that move the rough grinding unit 10 up and down along a pair of guide rails 8. When the pulse motor 16 is pulse-driven, the ball screw 14 rotates and the moving base 12 is moved in the vertical direction.

  A pair of guide rails 19 (only one is shown) 19 extending in the vertical direction are also fixed to the other column 6b. A finish grinding unit 28 is mounted along the pair of guide rails 19 so as to be movable in the vertical direction.

  The finish grinding unit 28 is attached to a moving base (not shown) in which the housing 36 moves in the vertical direction along the pair of guide rails 19. The finish grinding unit 28 includes a housing 36, a spindle (not shown) rotatably accommodated in the housing 36, a servo motor 38 that rotationally drives the spindle, and a grinding wheel 42 for finish grinding fixed to the tip of the spindle. A grinding wheel 40 is included.

  The finish grinding unit 28 includes a finish grinding unit moving mechanism 34 including a ball screw 30 and a pulse motor 32 that move the finish grinding unit 28 in the vertical direction along the pair of guide rails 19. When the pulse motor 32 is driven, the ball screw 30 rotates and the finish grinding unit 28 is moved in the vertical direction.

  The grinding device 2 includes a turntable 44 disposed so as to be substantially flush with the upper surface of the housing 4 on the front side of the columns 6a and 6b. The turntable 44 is formed in a relatively large-diameter disk shape, and is rotated in a direction indicated by an arrow 45 by a rotation drive mechanism (not shown).

  On the turntable 44, three chuck tables 46 are arranged so as to be rotatable in a horizontal plane, spaced from each other by 120 ° in the circumferential direction. The chuck table 46 has a suction chuck formed in a disk shape by a porous ceramic material, and sucks and holds the wafer placed on the holding surface of the suction chuck by operating a vacuum suction means.

  The three chuck tables 46 arranged on the turntable 44 are rotated in accordance with the turntable 44, so that the wafer loading / unloading area A, rough grinding area B, finish grinding area C, and wafer loading / unloading are performed. The region A is sequentially moved.

  In the front portion of the housing 4, a wafer cassette 50, a wafer transfer robot 54 having a link 51 and a hand 52, a positioning table 56 having a plurality of positioning pins 58, a wafer carry-in mechanism (loading arm) 60, and a wafer carry-out A mechanism (unloading arm) 62, a spinner cleaning device 64 that cleans and spin-drys the ground wafer, and a storage cassette 66 that stores the ground wafer that has been cleaned and spin-dried by the spinner cleaning device 64 are provided. ing.

  The spinner cleaning device 64 has a spinner table 68 that rotates while sucking and holding the ground semiconductor wafer. The spinner table 68 has a diameter that is approximately equal to or larger than the diameter of the semiconductor wafer.

  As shown in FIG. 4, the spinner table 68 includes a porous suction portion 70 that sucks and holds the wafer 11, and a base 72 that is formed of a metal such as SUS and surrounds the porous suction portion 70. Preferably, the upper surface 72a of the base 72 is formed as an irregular reflection surface. The upper surface (wafer holding surface) of the porous suction portion 70 and the upper surface 72a of the base 72 are formed flush with each other.

  The spinner cleaning device 64 has a cleaning water supply nozzle (not shown) that supplies cleaning water toward the ground wafer that is adsorbed and held on the spinner table 68. An imaging unit 76 that images the outer peripheral portion of the semiconductor wafer 11 is attached to the cover 74 of the spinner cleaning device 64 downward. As shown in FIG. 4, an illumination unit 78 that illuminates the outer periphery of the wafer 11 during imaging is attached to the imaging unit 76.

  When the wafer after finish grinding is positioned in the wafer loading / unloading area A by rotating the turntable 44, the suction pad 62b of the wafer unloading mechanism (unloading arm) 62 sucks the wafer, and the unloading arm 62 , The wafer is transported to the spinner table 68 of the spinner cleaning device 64 and sucked and held by the spinner table 68.

  The wafer held by the spinner table 68 is cleaned while rotating the spinner table 68 at about 800 rpm while supplying the cleaning water from the cleaning water supply nozzle, and after the cleaning, the supply of the cleaning water from the cleaning water supply nozzle is stopped. The spinner table 68 is rotated at a high speed such as about 3000 rpm to spin dry the washed wafer.

  The outer peripheral edge portion of the cleaned and spin-dried wafer 11 is imaged by the imaging means 76 while the illumination means 78 illuminates the outer peripheral edge portion of the wafer 11 and the upper surface 72 a of the base 72 of the spinner table 68.

  Since the back surface of the wafer 11 is mirror-finished, the illumination light from the illumination means 78 is specularly reflected at the outer peripheral edge portion of the wafer 11. On the other hand, since the upper surface 72 a of the base 72 of the spinner table 68 is not processed into a mirror surface, the illumination light is irregularly reflected by the upper surface 72 a of the base 72 of the spinner table 68.

  As a result, the outer peripheral edge portion of the wafer 11 is imaged whitish, and the upper surface 72a of the base 72 of the spinner table 68 is imaged blackish due to irregular reflection, so that the outer peripheral edge portion of the wafer 11 can be detected clearly.

  By continuously imaging with the imaging means 76 while rotating the spinner table 68, breakage such as chips and cracks formed on the outer peripheral portion of the wafer 11 can be easily detected.

  After the detection of chipping or cracking of the outer peripheral portion of the wafer is completed, the wafer 11 is sucked and held by the hand 52 of the wafer transfer robot 54 and is transferred by the wafer transfer robot 54 to be transferred to the wafer storage portion (wafer) of the storage cassette 66 shown in FIG. Accommodation shelf) 80. As shown in FIG. 5, the storage cassette 66 has a plurality of wafer storage portions (wafer storage shelves) 80. 82 is a handle.

  According to this embodiment, when the imaging means 76 images the outer peripheral portion of the wafer 11 and detects breakage such as chipping or cracking, the damage information of the wafer 11 and the accommodation position of the accommodation cassette 66 in which the wafer 11 is accommodated (wafer accommodation portion) The position 80 is stored in the controller of the grinding apparatus 2 correspondingly.

  As a result, after the grinding of the plurality of wafers 11 is completed, it is possible to determine in which position of the storage cassette 66 the damaged wafer 11 is stored, and the wafer 11 in which the damage is detected is not subjected to a subsequent process. Can be eliminated.

  As described above, according to the present embodiment, since the outer periphery of the wafer 11 that has been thinly ground, cleaned and spin-dried is imaged by the imaging unit 76, is there any damage on the outer periphery of each wafer 11 on the spinner table 68? Can be confirmed. Therefore, it is not necessary to use a separate inspection apparatus, and the inspection process by the inspection apparatus can be reduced. Further, since the wafer 11 does not move, damage during handling can be prevented.

  The grinding device 2 of the above-described embodiment includes the rough grinding unit 10 and the finish grinding unit 28. However, instead of the finish grinding unit 28, a grinding unit with a polishing buff attached to the tip is provided. For example, the back surface of the ground wafer can be polished to a mirror surface.

It is a surface side perspective view of a semiconductor wafer. It is a back surface side perspective view of the semiconductor wafer where the protective tape was stuck. 1 is an external perspective view of a grinding apparatus according to an embodiment of the present invention. It is a schematic diagram which shows the state at the time of imaging of the outer periphery edge part of a semiconductor wafer. It is a front view of a storage capacity set.

Explanation of symbols

2 Grinding device 10 Rough grinding unit 11 Semiconductor wafer 13 Street 15 Device 21 Notch 28 Finish grinding unit 44 Turntable 46 Chuck table 60 Wafer loading mechanism (loading arm)
62 Wafer unloading mechanism (unloading arm)
64 Spinner cleaning device 66 Capacity setting 68 Spinner table 76 Imaging means 78 Illumination means

Claims (2)

A chuck table for holding a workpiece, a processing means for grinding or polishing the back surface of the workpiece held on the chuck table to a desired thickness, and a spinner for cleaning and spin drying the ground or polished workpiece A processing apparatus comprising a cleaning device and a control means for controlling the spinner cleaning device,
The spinner cleaning device includes a spinner table having a diameter substantially equal to or larger than that of the workpiece and rotating while holding the workpiece.
A cleaning water supply nozzle for supplying cleaning water to the workpiece;
An imaging unit including an illumination unit that is disposed above the workpiece holding surface of the spinner table and detects damage by imaging the outer periphery of the cleaned and spin-dried workpiece;
A processing apparatus comprising: A storage cassette for storing the workpiece after the outer periphery is imaged by the imaging means;
A loading means for loading the workpiece on the spinner table into the storage cassette;
The storage cassette has a plurality of workpiece storage portions for storing a workpiece,
The control unit has a storage unit that stores the damage information of the workpiece detected by the imaging unit and stores the position of the workpiece storage unit in which the workpiece having the damage information is stored. The processing apparatus according to claim 1.

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