JP2012023174A - Carrying-out/in device for plate-shaped object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrying-out/in device for a plate-shaped object, capable of sucking and holding even a thin, warped wafer.SOLUTION: The carrying-out/in device for a plate-shaped object includes: a holding unit having a holding plane to suck and hold a plate-shaped object; and a bent arm mechanism for inserting the holding unit into a cassette, so as to carry the plate-shaped object accommodated in the cassette out of the cassette, or carry the plate-shaped object into the cassette. The holding unit includes: a suction port having an aperture on the holding plane; a negative pressure transmission path connected to a suction source, for transmitting a negative pressure to the suction port; and an adhesion pad composed of an elastic member disposed in a manner to enclose the suction port.

Description

  The present invention relates to a plate-like material carrying-in / out device for carrying out a plate-like material housed in a cassette from the cassette or carrying a plate-like material into the cassette.

  For example, in a semiconductor device manufacturing process, a plurality of circuit elements such as IC and LSI are formed on the surface of a wafer such as silicon or GaAs. The semiconductor wafer on which the circuit elements are formed is divided into individual semiconductor devices after the back surface is ground or polished by a grinding device or a polishing device and thinned to a predetermined thickness. Semiconductor devices manufactured in this way are widely used in electrical equipment such as mobile phones and personal computers.

  The wafers are supplied to a grinding device or a polishing device in a state where a plurality of wafers are accommodated in a cassette. The carry-in / out device carries out each wafer from the cassette placed on the cassette placement portion of the grinding device or polishing device.

  The unloaded wafer is transported to the chuck table and sucked and held by the chuck table via the protective tape. The grinding wheel or polishing pad abuts against the back surface of the wafer thus held, and slides on the wafer. The back side is ground or polished.

  The ground or polished wafer is cleaned and dried, and then accommodated in a cassette that is the same as or different from the original cassette by a carry-in / out device (see, for example, JP-A-2002-289673).

  The carry-in / out device includes at least a holding portion having a holding surface for sucking and holding a wafer that is a plate-like object, and a bending arm mechanism for inserting the holding portion into the cassette (see Japanese Patent Application Laid-Open No. 2002-270674). .

  On the other hand, with the trend of recent miniaturization and thinning of electric appliances, further thinning of semiconductor devices is required. When the wafer is thinned to, for example, 100 μm or less by grinding or polishing, the wafer is warped.

JP 2002-289673 A JP 2002-270674 A

  However, a warped wafer has a problem that it is difficult to hold by suction with a carry-in / out device. If the suction force is excessively increased to hold the suction, the thinned wafer may be damaged.

  The present invention has been made in view of these points, and an object of the present invention is to provide a carry-in / out apparatus capable of sucking and holding even a wafer that has been thinned and warped.

  According to the present invention, a holding part having a holding surface for sucking and holding a plate-like object and a bending arm mechanism for inserting the holding part into the cassette are provided, and the plate-like object accommodated in the cassette is placed in the cassette. A plate-like object carrying-in / out device for carrying out a plate-like object or carrying a plate-like object into the cassette, wherein the holding portion is connected to a suction port that opens on the holding surface and a suction source and is loaded on the suction port. There is provided a plate-like material carrying-in / out device comprising: a negative pressure transmission path for transmitting pressure; and a suction pad made of an elastic member disposed so as to surround the suction port.

  Since the suction pad made of an elastic member is disposed around the suction port, the carry-in / out apparatus of the present invention can reliably suck and hold a wafer that has been thinned and warped.

It is a surface side perspective view of a semiconductor wafer. It is a back surface side perspective view of a semiconductor wafer in the state where a protective tape was stuck on the surface. It is a perspective view of the grinding device provided with the carrying in / out device of the present invention. It is a perspective view of the carrying in / out apparatus which concerns on this invention embodiment. It is a perspective view of the carrying in / out apparatus concerning the embodiment of the present invention in the state where the wafer was sucked and held with the holding part. It is a top view of a holding part. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. It is sectional drawing which shows a mode that the wafer which curved in the holding | maintenance part of this embodiment is sucked and held.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a perspective view of a semiconductor wafer before being ground to a predetermined thickness is shown. 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 each region partitioned by the plurality of streets 13 is formed. Further, a device 15 such as an IC or LSI is formed.

  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.

  A protective tape 23 is attached to the surface 11a of the semiconductor wafer 11 by a protective tape attaching process. Therefore, 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.

  Referring to FIG. 3, there is shown a schematic perspective view of a grinding apparatus provided with the wafer carry-in / out device (plate-like product carry-in / out device) of the present invention. Reference numeral 4 denotes a base (housing) of the grinding apparatus 2, and two columns 6 a and 6 b are vertically provided behind the base 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 cassette 50 in which a wafer before grinding is accommodated, a cassette 66 in which the wafer after grinding is accommodated, and a wafer accommodated in the cassette 50 are unloaded and after grinding. A wafer carry-in / out device (wafer carrying robot) 54 for carrying the wafer into the cassette 66 is provided.

  As shown in FIG. 4, the wafer carry-in / out device 54 includes a bending arm mechanism 51 in which a plurality of arms are rotatably connected, and a wafer holding portion (hand) 52 connected to the tip of the bending arm mechanism 51. is doing.

  The bending arm mechanism 51 includes a support member 72 that is moved in the Z-axis direction (vertical direction) by a driving unit (not shown), a first arm 74 that is rotatably attached to the support member 72, and a first arm 74. And a second arm 76 attached to be rotatable.

  A wafer holding part (hand) 52 is attached to the tip of the second arm 76 via a drive part 77. As best shown in FIG. 6, three suction ports 80 are opened on the holding surface 52 a of the wafer 52, and suction pads 78 made of an elastic member are disposed so as to surround each suction port 80. Has been.

  A plurality of shelves 82 are formed inside the side walls 66 a of the cassette 66, and the wafer 11 is supported by the shelves 82 having corresponding heights on the left and right sides and accommodated in the cassette 66. The cassette 50 has the same configuration as the cassette 66.

  Referring again to FIG. 3, a positioning table 56 having a plurality of positioning pins 58, a wafer carry-in mechanism (loading arm) 60, and a wafer carry-out mechanism (unloading arm) 62 are adjacent to the wafer carry-in / out device 54. A spinner cleaning device 64 for cleaning and spin drying the ground wafer is provided.

  A spinner table 68 that rotates while sucking and holding the ground semiconductor wafer 11 is mounted on the spinner cleaning device 64. Reference numeral 70 denotes a cover of the spinner cleaning device 64.

  Referring to FIG. 5, a perspective view of the wafer loading / unloading device 54 in a state where the wafer 11 is sucked and held by the wafer holding portion 52 of the wafer loading / unloading device 54 is shown. In the state shown in FIG. 5, the wafer 11 is sucked and held from the spinner table 68 of the spinner cleaning device 64 by the wafer holding portion 52 of the wafer carry-in / out device 54, and the wafer 11 is placed in the uppermost shelf 82 of the cassette 66. It is in a state to try to contain.

  As shown in the enlarged view of FIG. 6, the holding surface 52a of the wafer holding portion 52 has three suction ports 80. As best shown in FIG. 7, each suction port 80 is made of an elastic member. The suction pad 78 is surrounded. Preferably, the suction pad 78 is made of urethane sponge having closed cells, for example, having a thickness of 1 to 2 mm. The suction pad 78 may be formed from rubber or a normal sponge.

  As shown in FIG. 7, the suction pad 78 is adhered to the holding surface 52 a of the wafer holding unit 52 with a double-sided tape 79. Preferably, the adhesion surface of the suction pad 78 and the double-sided tape 79 is subjected to a skin treatment.

  By applying the skin treatment to the urethane sponge, the adhesive force with the double-sided tape 79 is improved, and it is possible to prevent the suction pad 78 from being peeled off due to rubbing when the wafer is carried in and out.

  By using the double-sided tape 79 for bonding the suction pad 78, the suction pad 78 can be easily attached and detached. As shown in FIG. 6, each suction port 80 is connected to a negative pressure suction source 86 via a negative pressure transmission path 84.

  Next, with reference to FIG. 8, suction holding by the holding portion 52 of the wafer 11 which is thinly ground and warped will be described. As shown in FIG. 8A, the wafer 11 is sucked and held by the spinner table 68 of the spinner cleaning device 64. In this state, the wafer holding portion 52 of the wafer carry-in / out mechanism 54 is inserted and raised from below the spinner table 68.

  As shown in FIG. 8B, when the wafer holding portion 52 is raised and sucked from the suction port 80, the suction pad 78 formed of urethane sponge is crushed, and the wafer holding portion 52 sucks the wafer 11 having warpage. Can be held.

  While the wafer 11 is sucked and held by the holding portion 52 of the wafer carry-in / out mechanism 54, the suction of the spinner table 68 is released, and the wafer 11 is carried to the cassette 66 by the wafer carry-in / out mechanism 54 as shown in FIG.

  It is preferable that the wafer 11 is sucked and held by the spinner table 68 until the wafer 11 is sucked and held by the holding portion 52 of the wafer carry-in / out mechanism 54. However, even if the suction of the spinner table 68 is released early, the wafer 11 is sucked and held. The wafer 11 can be sucked and held by the holding portion 52 of the wafer carry-in / out mechanism 54.

  In the wafer loading / unloading mechanism 54 described above, since the suction pad 78 made of an elastic member is disposed around the suction port 80 of the wafer holding portion 52, even the wafer 11 that has been thinly ground and warped is not included in the wafer loading / unloading device 54. The holding unit 52 can suck and hold the wafer 11, and the warped wafer 11 can be conveyed from the spinner table 68 of the spinner cleaning device 64 to the cassette 66.

  In the above-described embodiment, the example in which the wafer carry-in / out mechanism 54 of the present invention is applied to the grinding apparatus 2 has been described. However, the wafer carry-in / out mechanism of the present invention is a wafer in which the wafer 11 is thinly polished and warped. The present invention can also be applied to a wafer carry-in / out mechanism of a polishing apparatus that conveys the wafer.

2 Grinding device 10 Rough grinding unit 11 Semiconductor wafer 28 Finish grinding unit 44 Turntable 46 Chuck table 50, 66 Cassette 51 Bending arm mechanism 52 Wafer holding part (hand)
54 Wafer loading / unloading mechanism 68 Spinner table 78 Suction pad 80 Suction port

Claims (1)

A holding part having a holding surface for sucking and holding a plate-like object and a bending arm mechanism for inserting the holding part into the cassette, and carrying out the plate-like object accommodated in the cassette from the cassette or the cassette A plate-like material carry-in / out device for carrying a plate-like material into the inside,
The holding part is
A suction port opening in the holding surface;
A negative pressure transmission path connected to a suction source and transmitting negative pressure to the suction port;
A suction pad made of an elastic member disposed so as to surround the suction port;
The board | substrate carrying-in / out apparatus characterized by having comprised.

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