JP5831870B2 - Chuck table and processing apparatus including the chuck table - Google Patents

Description

  The present invention includes a chuck table for holding a plate-like object unit comprising a support substrate made of a rigid body and a plate-like object having an area smaller than the support substrate and fixed on the support substrate, and the chuck table. It relates to a processing apparatus.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a semiconductor wafer having a substantially disk shape, and devices such as ICs, LSIs, etc. are partitioned in the partitioned regions. Form. Then, the semiconductor wafer is divided into individual semiconductor chips (devices) by cutting the semiconductor wafer along a street with a cutting device.

  The semiconductor wafer to be divided is ground to the predetermined thickness by grinding the back surface before cutting along the street. In recent years, in order to achieve a reduction in weight and size of electrical equipment, it has been required to make the wafer thinner, for example, about 50 μm.

  Since a wafer that has been thinly ground in this way is likely to be warped and difficult to handle, for example, after attaching the wafer on a support substrate made of a rigid body as disclosed in JP-A-2004-207606, In some cases, the support substrate is sucked and held by a chuck table and the wafer is subjected to processing such as grinding or cutting.

  As a chuck table of a processing apparatus such as a cutting apparatus or a grinding apparatus, there are many forms that suck and hold a workpiece such as a wafer, such as a porous ceramic disclosed in Japanese Patent Laid-Open No. 9-162269. A chuck table in which a suction holding portion made of a porous material is fitted to a frame body made of metal is widely used.

JP 2004-207606 A JP 2001-135598 A JP-A-9-162269

  Since the conventional chuck table as described above is manufactured by processing a plurality of materials and combining them with each other, it takes a lot of manufacturing steps and is very expensive. In view of this, it is conceivable to reduce the number of manufacturing steps and the manufacturing cost by providing a suction hole for sucking and holding a workpiece on a chuck table made of a single material.

  However, if a plate-like object stuck on a support substrate made of a rigid body is sucked and held by such a chuck table, a local suction force acts on the suction hole portion, and the support substrate is slightly bent, so that the accuracy is high. There was a problem that the workpiece could not be processed.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a chuck table capable of processing a workpiece adhered to a support substrate made of a rigid body with high accuracy, and the chuck table. It is providing the processing apparatus provided with.

According to the first aspect of the present invention, there is provided a chuck table for holding a plate-like object unit comprising a support substrate made of a rigid body and a plate-like object having an area smaller than that of the support substrate and fixed on the support substrate. A holding surface for holding the support substrate side of the plate- like object unit, and when the plate- like object unit is held on the holding surface , the outer edge of the plate-like object is inside the outer periphery of the support substrate. A suction groove formed on the outer holding surface, a suction path having one end communicating with the suction groove and the other end communicating with a suction source, and formed from a single material. A chuck table is provided.

According to the invention of claim 2, the chuck table of claim 1, an annular suction groove for sucking and holding the chuck table, a first suction path for selectively communicating the annular suction groove with a suction source, and A table base having a recess communicating with the suction path of the chuck table and a second suction path selectively communicating the recess with a suction source; and a table base for sucking and holding the chuck table; There is provided a processing device including processing means for processing the plate-like object of the plate-like object unit that is sucked and held by the chuck table.

  In the chuck table of the present invention, suction grooves are formed on the holding surface on the inner side of the outer peripheral edge of the support substrate and on the outer side of the outer peripheral edge of the plate-like object. Does not act, and the plate-like object can be processed with high accuracy.

It is a perspective view of the grinding device provided with the chuck table of the present invention. It is a perspective view of the chuck table of an embodiment of the present invention. It is a longitudinal cross-sectional view of the chuck table which concerns on embodiment. It is a perspective view explaining the grinding method of a wafer unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown a perspective view of a grinding apparatus 2 having a chuck table of the present invention. Reference numeral 4 denotes a base 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 21 (see FIG. 4) rotatably accommodated in the housing 20, a servo motor 22 that rotationally drives the spindle 21, and a wheel mount fixed to the tip of the spindle 21. 23 and a grinding wheel 24 detachably attached to the wheel mount 23. The grinding wheel 24 includes a wheel base 25 and a plurality of grinding wheels 26 fixed to the outer periphery of the lower surface of the wheel base 25.

  The rough grinding unit 10 includes a rough grinding unit feed 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, a wheel mount fixed to the tip of the spindle, and a detachable attachment to the wheel mount. A grinding wheel 40 having a grinding wheel 42 for finish grinding, which is mounted as possible, is included.

  The finish grinding unit 28 includes a finish grinding unit feed mechanism 34 including a ball screw 30 that moves the finish grinding unit 28 in the vertical direction along the pair of guide rails 19 and a pulse motor 32. 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 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.

  Next, with reference to FIG.2 and FIG.3, the detailed structure of the chuck table 46 of this embodiment is demonstrated. As shown in FIGS. 3 and 4, the chuck table 46 holds a wafer unit 15 including a support substrate 13 made of a rigid body and a wafer 11 having an area smaller than the support substrate 13 and fixed on the support substrate 13. Especially suitable for doing. The support substrate 13 is made of silicon, glass or the like. In order to protect the device formed on the surface of the wafer 11, the wafer 11 is stuck on the support substrate 13 with the surface down.

The chuck table 46 is entirely made of ceramics, and includes a holding surface 46 a for holding the support unit 13 side of the wafer unit 15, an inner side of the outer peripheral edge of the support substrate 13 held by the chuck table 46, and the outside of the wafer 11. An annular suction groove 74 formed in the holding surface 46 a outside the peripheral edge and a plurality of suction holes 76 having one end communicating with the annular suction groove 74 are provided.

  The chuck table 46 is mounted on a table base 72 formed of a metal such as SUS. The table base 72 has a recess 78 that communicates with the other end of the suction hole 76, and a suction path 80 formed in the approximate center of the recess 78. The suction path 80 is connected to a suction source 84 via a switching valve 82. It is connected to the.

  The table base 72 further has an annular suction groove 86 for sucking and holding the chuck table 46 and a suction path 88 communicating with the annular suction groove 86. The suction path 88 is connected to the suction source 84 via the switching valve 90.

  When the switching valve 90 is switched to the illustrated position, the annular suction groove 86 is connected to the suction source 84 and the chuck table 46 is sucked and held by the table base 72. On the other hand, by switching the switching valve 82 to the illustrated position, the annular suction groove 74 is connected to the suction source 84 via the suction hole 76, the recess 78, and the suction path 80, and the support substrate 13 of the wafer unit 15 is connected to the chuck table 46. Is sucked in.

  Since the annular suction groove 74 is formed on the holding surface 46a on the inner side of the outer peripheral edge of the support substrate 13 of the wafer unit 15 held on the chuck table 46 and on the outer side of the outer peripheral edge of the wafer 11, the region corresponding to the wafer 11 is formed. In this case, the wafer unit 15 is sucked and held on the chuck table 46 without a local suction force acting.

  Next, the rough grinding process of the wafer unit 15 will be described with reference to FIG. After the wafer unit 15 is sucked and held by the chuck table 46, the turntable 40 is rotated counterclockwise to position the chuck table 46 holding the wafer unit 15 in the rough grinding region shown in FIG.

  Then, while rotating the chuck table 46 in the direction of the arrow a at 300 rpm, for example, the grinding wheel 21 is rotated in the direction of the arrow b at 6000 rpm, for example, and the rough grinding unit feed mechanism 18 is operated to rotate the grinding wheel 26 for rough grinding. The wafer 11 is brought into contact with the back surface 11 b of the wafer 11.

  Further, the grinding wheel 24 is ground and fed by a predetermined amount at a predetermined grinding feed speed, and the back surface 11b of the wafer 11 is ground. The wafer is ground to a desired thickness while measuring the thickness of the wafer 11 of the wafer unit 15 with a contact-type or non-contact-type thickness measurement gauge.

  The wafer after the rough grinding is positioned in the finish grinding region C by rotating the turntable 44 further 120 degrees counterclockwise, and finish grinding is performed by the finish grinding unit 28 having the finish grinding wheel 42. .

  As described above, the chuck table 46 of the present embodiment sucks and holds the support substrate 13 outside the outer peripheral edge of the wafer 11 by the annular groove 74 formed in the holding surface 46a. Does not work. Therefore, rough grinding by the rough grinding unit 10 and finish grinding by the finish grinding unit 28 can be performed with high accuracy.

  Further, the chuck table 46 of the present embodiment is formed of a single piece of ceramics, and the annular suction groove 74 and the suction hole 76 for sucking and holding the wafer 11 are formed on the chuck table 46. Compared to a table, it can be kept low.

  In the above-described embodiment, the example in which the chuck table 46 of the present invention is applied to a grinding device has been described. However, the chuck table 46 of the present invention is also applicable to other processing devices such as a cutting device, a cutting tool, a laser processing device, and the like. Can be applied to.

DESCRIPTION OF SYMBOLS 10 Rough grinding unit 11 Wafer 13 Support substrate 15 Wafer unit 28 Finish grinding unit 44 Turntable 46 Chuck table 46a Holding surface 72 Table base 74 Annular suction groove 76 Suction hole 78 Recess 80 Suction path 84 Suction source

Claims (2)

A chuck table for holding a plate-like object unit comprising a support substrate made of a rigid body and a plate-like object having an area smaller than the support substrate and fixed on the support substrate,
A holding surface for holding the support substrate side of the plate unit;
When the plate unit is held on the holding surface, a suction groove formed on the holding surface inside the outer peripheral edge of the support substrate and outside the outer peripheral edge of the plate-like object;
A suction path with one end communicating with the suction groove and the other end communicating with a suction source ;
A chuck table formed of a single material . A chuck table according to claim 1;
An annular suction groove for sucking and holding the chuck table, a first suction path that selectively communicates the annular suction groove with a suction source, a recess that communicates with the suction path of the chuck table, and the recess as a suction source A second base for selectively communicating, a table base for sucking and holding the chuck table ;
Processing means for processing the plate-like object of the plate-like object unit that is sucked and held by the chuck table via the table base ;
A processing apparatus comprising:

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