JP2012187654A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manual type grinding device allowing the efficient rough-grinding and finish-grinding of a wafer, and requiring only a small area for installation.SOLUTION: The grinding device includes a chuck table for holding a workpiece, a grinding means for grinding the workpiece held by the chuck table, and a locating means for locating the chuck table at a carry-on/out position where the workpiece is carried on and out of the chuck table or a grinding position where the workpiece held by the chuck table is ground, the grinding means including a first grinding means and a second grinding means disposed on a straight line between the carry-on/out position and the grinding position. It further includes a first grinding feed means for moving the first grinding means close to or away from the chuck table, and a second grinding feed means for moving the second grinding means close to or away from the chuck table.

Description

  The present invention relates to a manual grinding apparatus in which an operator attaches / detaches a wafer to / from a chuck table.

  A semiconductor wafer in which a number of devices such as IC and LSI are formed on the surface, and each device is partitioned by a line to be divided (street), the back surface is ground by a grinding machine and processed to a predetermined thickness. A dividing line is cut by a cutting device (dicing device) to be divided into individual devices, and the divided devices are widely used in various electric devices such as mobile phones and personal computers.

  A grinding apparatus grinds a workpiece, such as a wafer, a chuck table for holding a workpiece, a grinding means for grinding the workpiece held on the chuck table, a loading / unloading position for loading / unloading the workpiece, and the workpiece. Positioning means for positioning the chuck table at the grinding position is provided, and the workpiece can be ground to a desired thickness.

  The grinding apparatus automatically carries out the wafer from the cassette and grinds it, and then cleans the ground wafer and accommodates it in the cassette (for example, see Japanese Patent Application Laid-Open No. 2001-1261), an operator Are divided into manual type grinding devices (for example, see Japanese Patent Application Laid-Open No. 2005-246491) for attaching / detaching a wafer to / from the chuck table. For users who intend to make effective use of the installation area, a manual type with a small installation area is available. Selected.

JP 2001-1261 A JP 2005-246491 A

  However, for users who have selected a manual type grinding machine, it is uneconomical to prepare two manual type grinding machines in order to coarsely grind the wafer and then finish grinding the wafer. Therefore, there is a problem that productivity is poor because the wafer must be transferred from the chuck table to the chuck table. Moreover, when two manual type grinding machines are installed, there is a problem that the effective use of the installation area cannot be achieved.

  The present invention has been made in view of these points, and an object of the present invention is to provide a manual type grinding apparatus that can efficiently perform rough grinding and finish grinding of a wafer and has a small installation area. .

  According to the present invention, a chuck table for holding a workpiece, a grinding means for grinding the workpiece held on the chuck table, a loading / unloading position for loading and unloading the workpiece on the chuck table, and the chuck table And a positioning device for positioning the chuck table at a grinding position for grinding the workpiece held on the workpiece, wherein the grinding device is on a straight line connecting the carry-in / out position and the grinding position. A first grinding feed means including a first grinding means and a second grinding means disposed, the first grinding feed means approaching and separating the first grinding means from the chuck table; and the chuck table There is provided a grinding apparatus comprising a second grinding feed means for approaching and separating the second grinding means.

  Preferably, the first grinding means is disposed closer to the loading / unloading position side than the second grinding means, and a grinding wheel for rough grinding is disposed in the first grinding means in an annular shape. The second grinding means is equipped with a grinding wheel in which grinding wheels for finish grinding are annularly arranged.

  The grinding apparatus of the present invention includes a first grinding means and a second grinding means arranged on a straight line connecting a carry-in / out position for carrying a workpiece in and out of the chuck table and a grinding position, A first grinding feed means for moving the first grinding means toward and away from the chuck table; and a second grinding feed means for bringing the second grinding means closer to and away from the chuck table. It is possible to efficiently perform rough grinding and finish grinding of a workpiece with a small installation area.

It is a surface side perspective view of a semiconductor wafer. It is a back surface side perspective view of the semiconductor wafer by which the protective tape was stuck on the surface. 1 is a perspective view of a grinding apparatus according to an embodiment of the present invention. FIG. 4A is a perspective view showing the positional relationship between the grinding wheel during rough grinding and the wafer held by the chuck table, and FIG. 4B shows the grinding wheel during finish grinding and the wafer held by the chuck table. It is a perspective view which shows these positional relationships.

  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 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 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.

  Before grinding the back surface 11b of the semiconductor wafer 11, a protective tape 23 is attached to the front surface 11a of the semiconductor wafer 11 to protect the device 15. Therefore, as shown in FIG. 2, the semiconductor wafer 11 supplied to the grinding apparatus has a form in which the front surface 11a is protected by the protective tape 23 and the back surface 11b is exposed.

  Next, with reference to FIG. 3, the grinding apparatus 2 of this embodiment is demonstrated in detail. Reference numeral 4 denotes a base of the grinding apparatus 2, and a column 6 is erected at the center of the base 4 and a column 8 is erected at the rear. An opening 6 a is formed at the lower end of the column 6.

  A pair of guide rails 10 extending in the vertical direction are fixed to the column 6. A rough grinding unit (rough grinding means) 12 is mounted along the pair of guide rails 10 so as to be movable in the vertical direction.

  The rough grinding unit 12 includes a housing 14 and a holding portion 16 that holds the housing 14. The holding portion 16 is attached to a moving base 18 that moves in the vertical direction along the pair of guide rails 10. .

  Referring also to FIG. 4, the rough grinding unit 12 includes a spindle 20 that is rotatably accommodated in a housing 14, a wheel mount 22 that is fixed to the tip of the spindle 20, and a screw that is detachably attached to the wheel mount 22. And a rough grinding wheel 24 and a servo motor 30 for rotating the spindle 20. The rough grinding wheel 24 includes an annular base 26 and a plurality of rough grinding wheels 28 arranged annularly on the outer periphery of the lower end of the annular base 26.

  The grinding apparatus 2 includes a rough grinding unit feed mechanism 36 including a ball screw 32 and a pulse motor 34 that move the rough grinding unit 12 in the vertical direction along the pair of guide rails 10. When the pulse motor 34 is driven, the ball screw 32 is rotated and the moving base 18 is moved in the vertical direction.

  A recess 4a is formed on the upper surface of the base 4, and a chuck table mechanism 38 is disposed in the recess 4a. The chuck table mechanism 38 includes a chuck table 40. A wafer loading / unloading position A shown in FIG. 3 by a moving mechanism (not shown), a rough grinding position B facing the rough grinding unit 12, and finish grinding described later. It is moved in the Y-axis direction between the finish grinding position C facing the unit 48. Reference numeral 42 denotes a bellows. An operation panel 44 is provided on the front side of the base 4 so that an operator of the grinding apparatus 2 can input grinding conditions and the like.

  On the other hand, a pair of guide rails 46 extending in the vertical direction are fixed to the column 8. A finish grinding unit (finish grinding means) 48 is mounted along the pair of guide rails 46 so as to be movable in the vertical direction.

  The finish grinding unit 48 includes a housing 50 and a support portion 52 that supports the housing 50, and the support portion 52 is attached to a moving base 54 that moves up and down along a pair of guide rails 46. .

  Referring also to FIG. 4, the finish grinding unit 48 includes a spindle 56 rotatably accommodated in a housing 50, a wheel mount 58 fixed to the tip of the spindle 56, and a screw mount detachably attached to the wheel mount 58. A finish grinding wheel 60 and a servo motor 66 for rotating the spindle 48 are included. The finish grinding wheel 60 includes an annular base 62 and a plurality of finish grinding wheels 64 arranged annularly on the outer periphery of the lower end of the annular base 62.

  The grinding apparatus 2 includes a finish grinding unit feeding mechanism 72 including a ball screw 68 and a pulse motor 70 that move the finish grinding unit 48 in the vertical direction along a pair of guide rails 46. When the pulse motor 70 is pulse-driven, the ball screw 68 rotates and the moving base 54 is moved in the vertical direction.

  The grinding operation of the grinding device 2 configured as described above will be described below. The operator places the wafer 11 with the protective tape 23 shown in FIG. 2 on the chuck table 40 positioned at the wafer loading / unloading position A shown in FIG. The wafer 11 is sucked and held by operating the pressure suction source. Next, the chuck table 40 is moved in the Y-axis direction and positioned at the rough grinding position B.

  With respect to the wafer 11 positioned in this manner, as shown in FIG. 4A, the grinding wheel 24 is rotated in the same direction as the chuck table 40 while rotating the chuck table 40 in the direction of arrow a at 300 rpm, for example. While rotating in the direction of arrow b at, for example, 6000 rpm, the rough grinding unit feed mechanism 36 is operated to bring the rough grinding wheel 28 into contact with the back surface 11 b of the wafer 11.

  Then, the rough grinding wheel 24 is ground and fed by a predetermined amount at a predetermined grinding feed speed (for example, 3.0 μm / second) to perform rough grinding of the wafer 11. The wafer is finished to a desired thickness, for example, 100 μm, while measuring the thickness of the wafer 11 with a contact-type or non-contact-type thickness gauge (not shown). When rough grinding is performed, the grinding striations 31 exhibiting a pattern in which a large number of arcs are radially drawn remain on the back surface (surface to be ground) 11 b of the wafer 11.

  When the rough grinding is completed, the chuck table moving mechanism is driven to move the wafer 11 held by the chuck table 40 in the Y-axis direction through the opening 6a of the column 6 and is positioned at the finish grinding position C.

  As shown in FIG. 4B, the finish grinding wheel 60 is rotated in the same direction as the chuck table 40 while rotating the chuck table 40 in the direction of arrow a at 300 rpm, for example, with respect to the wafer 11 thus positioned. That is, while rotating in the direction of arrow b at, for example, 6000 rpm, the finish grinding unit feed mechanism 72 is operated to bring the finish grinding wheel 64 into contact with the back surface 11 b of the wafer 11.

  Then, the finish grinding wheel 60 is ground and fed downward by a predetermined amount at a predetermined grinding feed rate (for example, 0.3 μm / second), and the finish grinding of the wafer 11 is performed. The wafer is finished to a desired thickness, for example, 95 μm while measuring the thickness of the wafer 11 with a contact-type or non-contact-type thickness measurement gauge (not shown).

  When the finish grinding is performed, the grinding striations 31 at the time of rough grinding are removed by grinding, and the grinding striations 33 at the time of finish grinding by the finish grinding grindstone 64 remain on the back surface (surface to be ground) 11 b of the wafer 11.

  The wafer 11 for which finish grinding has been completed is returned to the wafer loading / unloading position A by driving the chuck table moving mechanism, and the operator removes the wafer 11 for which finish grinding has been completed from the chuck table 40.

  In the grinding apparatus 2 according to the above-described embodiment, the rough grinding unit 12 and the finish grinding unit 48 are arranged on a straight line connecting the wafer carry-in / out position A and the finish grinding position C, and the rough grinding unit 12 with respect to the chuck table 40. Are provided with a rough grinding unit feed mechanism 36 for approaching and moving away from the chuck table 40 and a finish grinding unit feed mechanism 72 for moving the finish grinding unit 48 toward and away from the chuck table 40. Therefore, the rough grinding of the wafer 11 can be efficiently performed with a small installation area. Grinding and finish grinding can be performed.

2 Grinding device 11 Semiconductor wafer 12 Rough grinding unit 24 Rough grinding wheel 28 Rough grinding wheel 36 Rough grinding unit feed mechanism 40 Chuck table 48 Finish grinding unit 60 Finish grinding wheel 64 Finish grinding wheel 72 Finish grinding unit feed mechanism

Claims (2)

A chuck table for holding the workpiece, a grinding means for grinding the workpiece held on the chuck table, a loading / unloading position for loading / unloading the workpiece on the chuck table, and a workpiece held on the chuck table A positioning device for positioning the chuck table at a grinding position for grinding a workpiece,
The grinding means includes a first grinding means and a second grinding means arranged on a straight line connecting the carry-in / out position and the grinding position,
First grinding feed means for moving the first grinding means toward and away from the chuck table;
Second grinding feed means for moving the second grinding means toward and away from the chuck table;
A grinding apparatus comprising:   The first grinding means is disposed closer to the loading / unloading position side than the second grinding means, and the first grinding means is equipped with a grinding wheel in which a grinding wheel for rough grinding is annularly disposed. 2. A grinding apparatus according to claim 1, wherein said second grinding means is equipped with a grinding wheel in which grinding wheels for finish grinding are annularly arranged.

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