JPH11309673A - Spindle slant angle adjusting mechanism of flattening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the slant angle of a spindle easily and also minutely. SOLUTION: A surface grinding device 18 for grinding the back surface of a wafer 26 is composed of a casing 70, feed table 72, tilt block 74 and spindle casing 76. The slant angle adjustment of Y direction of the tilt block 74 for the feed table 72 is adjusted by a feed screw device 78. The slant angle adjustment of X direction of the spindle casing 76 for the tilt block 74 is adjusted by using a spacer drive device 80 having the spacer 108 with a wedge shape section and a joint bar 82.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle tilt angle adjusting mechanism of a plane processing apparatus, and more particularly to a spindle tilt angle adjusting mechanism of a plane processing apparatus for grinding a back surface of a semiconductor wafer in a semiconductor wafer manufacturing process.

[0002]

2. Description of the Related Art A planar processing apparatus for grinding the back surface of a semiconductor wafer includes a table and a cup-shaped grindstone. The table holds the surface of the semiconductor wafer by suction, and the cup-shaped grindstone is attached to the back surface of the semiconductor wafer. Is pressed, and the table and the cup-shaped grindstone are rotated to grind the back surface of the wafer.

In such a wafer surface grinding apparatus,
As a method for ultra-precise grinding of a wafer, it is known to fix a spindle of a cup-shaped grindstone with a slight inclination with respect to a table and grind the wafer in this state. According to such a grinding method, an increase in grinding resistance can be prevented because the contact area between the cup-shaped grindstone and the wafer is reduced, and the cooling efficiency by cutting water is improved.
There is an effect that the saw mark after grinding becomes radial in a regular direction from the center of the wafer toward the outer periphery.

Therefore, a conventional wafer surface grinding apparatus is provided with a tilt angle adjusting mechanism for tilting a spindle of a cup-type grindstone. As the tilt angle adjusting mechanism disclosed in Japanese Patent Application Laid-Open No. 2-274462,
After adjusting the tilt angle by loosening the load supporting bolt and the adjusting bolt, the load supporting bolt and the adjusting bolt are fastened to fix the tilt angle.

[0005]

However, the tilt angle adjusting mechanism disclosed in Japanese Patent Application Laid-Open No. 2-274462 requires manual operation of the load supporting bolt and the adjusting bolt every time the tilt angle is changed. However, there are drawbacks in that the adjustment takes time and fine adjustment is very difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a spindle inclination angle adjusting mechanism of a plane machining apparatus which can easily adjust the inclination angle of a spindle and easily perform fine adjustment. With the goal.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an apparatus main body, a table rotatably provided on the apparatus main body and holding a wafer, and an elevating device provided in parallel with the table. A casing provided, a Z-direction moving unit moved up and down by a casing elevating device, a Y-direction swinging unit supported by the Z-direction moving unit to be swingable in a Y direction orthogonal to the Z direction, The direction swing part is Z
A Y-direction oscillating means for oscillating in the Y-direction with respect to the direction-moving portion; and the Y-direction oscillating portion is supported swingably in an X-direction orthogonal to the Y-direction and the Z-direction. An X-direction oscillating portion provided with a spindle of a grindstone or polishing cloth to be processed and a motor for rotating the spindle, and an X-direction for oscillating the X-direction oscillating portion in the X-direction with respect to the Y-direction oscillating portion Swing means for swinging the Y-direction swing unit and the X-direction swing unit to adjust the inclination angle of the spindle with respect to the wafer, and lowering the whetstone or the polishing cloth with the Z-direction movement unit. In the planar processing apparatus for processing a wafer by rotating the wafer with a grindstone or a polishing cloth, the X-direction oscillating portion is oscillated by the Y-direction oscillating portion via a cylindrical joint member. Freely supported, the X The direction swinging means includes a substantially wedge-shaped spacer member, and a drive unit that fits the spacer member into a gap between the X-direction swing unit and the Y-direction swing unit to swing the X-direction swing unit. The swing angle of the X-direction swing unit is controlled by controlling the amount of insertion of the spacer member by the drive unit.

According to the present invention, when the driving portion drives the wedge-shaped spacer member and inserts the spacer member into the gap between the X-direction oscillating portion and the Y-direction oscillating portion, the X-direction oscillating portion becomes Y
Since the swing member is swingably supported by the direction swing portion via a cylindrical joint member, the swing member swings in the X direction using the circumferential surface of the joint member as a guide, and the inclination angle is adjusted. Therefore, according to the present invention, the adjustment of the inclination angle can be performed without trouble. Further, the fine adjustment of the inclination angle can be performed only by controlling the fitting amount of the spacer member by the driving unit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a spindle inclination angle adjusting mechanism of a flattening apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of a semiconductor wafer surface grinding apparatus to which the present invention is applied.
FIG. 2 is a plan view. As shown in FIG.
The main body 12 includes a cassette housing stage 14, an alignment stage 16, a rough grinding stage 18, a finish grinding stage 20, and a cleaning stage 22.

Two cassettes 24, 24 are removably set on the cassette storage stage 14, and these cassettes 24, 24 store a large number of wafers 26 before back grinding. The wafers 26 are held one by one by a transfer robot 28 and sequentially transferred to the alignment stage 16 which is the next step. The transfer robot 28 is suspended and supported by a beam 30 erected on the main body 12 via an elevating device 32. The elevating device 32 is connected to a feed screw device (not shown) built in the beam 30. When the elevating device 32 is moved by the feed screw device, the transport robot 28 It can reciprocate in the directions indicated by the arrows A and B in FIGS. 1 and 2 along the arrangement direction.

When the transfer robot 28 is suspended and supported as in the present embodiment, the distance between the cassette housing stage 14 and the alignment stage 16 can be reduced, so that the size of the surface grinding apparatus 10 can be reduced. That is, when the transfer robot 28 is installed on the upper surface of the apparatus main body 12, the transfer robot 28 must be installed in the space between the cassette storage stage 14 and the alignment stage 16 because of the transfer of the wafer 26. For this reason, the surface grinding device 10 is unnecessarily increased in size by the space. On the other hand, in the surface grinding apparatus 10 of the present embodiment, the space above the apparatus main body 12 is effectively used as an installation space and an operation space for the transfer robot 28, so that the apparatus can be downsized.

The robot 28 is a general-purpose industrial robot having a horseshoe-shaped arm 34 for holding the wafer 26 by suction, and three links 36, 38, 40 and the like. At the tip of the arm 34, suction pads 35, 35 for sucking the wafer 26 are provided. The base end of the arm 34 is rotatably supported by a link 36 about an axis, and can be rotated about the axis by a driving force from a motor (not shown). Link 3
6 is rotatably connected to the link 38 via a shaft 42, and can rotate around the shaft 42 by a driving force from a motor (not shown). The link 38 is rotatably connected to the link 40 via a shaft 44, and can rotate around the shaft 44 by a driving force from a motor (not shown). Further, since the link 40 is connected to an output shaft of a motor (not shown) via the shaft 46, the link 40 can be rotated around the shaft 46 by driving the motor. The motor is connected to a lifting rod (not shown) of the lifting device 32. Therefore, according to the robot 28, the operations of the arm 34 and the three links 36, 38, and 40 are controlled by the respective motors, and the retracting operation of the lifting rod of the lifting device 32 is controlled. Can be taken out and transferred to the alignment stage 16.

The alignment stage 16 is a stage for aligning the wafer 26 transferred from the cassette 24 to a predetermined position. The wafer 26 aligned by the alignment stage 16 is sucked and held by the suction pads 35 of the transfer robot 28 again, and then transferred toward an empty chuck table 48. It is sucked and held at the position.

The chuck table 48 is installed on a turntable 50, and chuck tables 52 and 54 having the same function are installed on the turntable 52 at predetermined intervals. The chuck table 52 includes:
The wafer 26 that has been positioned on the rough grinding stage 18 and has been attracted is roughly ground here. The chuck table 54 is located on the finish grinding stage 20, and the attracted wafer 26 is subjected to finish grinding (fine grinding, spark out).

The thickness of the wafer 26 sucked and held on the chuck table 48 is measured by a measuring gauge (not shown). The wafer 26 whose thickness has been measured is
The turntable 52 is positioned on the coarse grinding stage 18 by turning in the direction of the arrow C in FIGS. 1 and 2 and coarsely ground by the cup-type grindstone 56 of the coarse grinding stage 18 based on the thickness. The rough grinding stage 18 will be described later.

The thickness of the wafer 26 roughly ground by the coarse grinding stage 18 is measured by a thickness gauge (not shown) after the cup-shaped grindstone 56 is retreated from the wafer 26. The wafer 26 whose thickness has been measured is turned on the finish grinding stage 2 by turning the turntable 52 in the same direction.
The fine grinding and spark-out are performed based on the thickness by the cup-type grindstone 64 of the finish grinding stage 20 shown in FIG. Since the structure of the finish grinding stage 20 is the same as the structure of the coarse grinding stage 18, a description of the structure of the coarse grinding stage 18 will be omitted below.

The wafer 26 finish-ground by the finish grinding stage 20 is separated from the wafer 26 by a cup-shaped grindstone 64.
Is moved to the position of the empty chuck table 48 shown in FIG. 1 by turning the turntable 50 in the same direction. Then, the wafer 26 is transferred to the transfer arm 6.
6, a suction pad 68 having substantially the same diameter as the wafer.
Is transported to the cleaning stage 22 by the rotation of the transport arm 66 in the direction of the arrow D in FIG. 1, where it is cleaned and dried.

The wafer 26 cleaned / dried by the cleaning stage 22 is sucked and held by the transfer robot 28, transferred to the cassette storage stage 14, and stored on a predetermined shelf of a predetermined cassette 24. The above is the flow of the wafer processing step by the surface grinding apparatus 10 of the present embodiment. Next, the rough grinding stage 18 will be described.

As shown in FIG.
Are mainly a casing 70, a feed table (Z-direction moving unit) 72, a tilt block (Y-direction swinging unit) 7.
4, a spindle casing (X-direction swinging unit) 76, a feed screw device (Y-direction swinging unit) 78, a spacer driving device (X-direction swinging unit) 80, a joint bar (joint member) 82, and the like. I have.

The casing 70 is erected on the main body 12, and a feed screw device (elevator) (not shown) is provided inside the casing 70. The feed table 72 is provided movably up and down with respect to the casing 70 via an LM (linear motion) guide (not shown).
The nut portion is screwed to a threaded rod of the feed screw device provided inside. Therefore, the feed table 72
Can be moved up and down by driving the feed screw device.

The tilt block 74 is swingably supported on the feed table 72 via a pin 84. The pin 84 projects horizontally from the side surface of the feed table 72, and a tilt block 74 is supported at the tip of the pin 84. Therefore,
The tilt block 74 can swing around the pin 84, that is, in the Y direction.

The tilt block 74 is swung by a feed screw device 78. This feed screw device 78 is shown in FIG.
As shown in the figure, the motor 86 and the screw rod 88 are provided. The motor 86 is fixed to a side surface of a U-shaped frame 90 fixed to the upper surface of the feed table 72, and the screw rod 88 is connected to a spindle of the motor 86. The screw rod 88 is inserted and arranged in a through hole 91 formed in the frame 90, and a tip end thereof is screwed to a projection 75 projecting from an upper end of the tilt block 74. Therefore, when the motor 86 is driven to rotate the screw rod 88, the protrusion 75 moves forward and backward with respect to the motor 86 by the screwing action between the screw rod 88 and the protrusion 75. As a result, the tilt block 74 swings in the Y direction with the pin 84 as a fulcrum.

As shown in FIG. 3, a spindle casing 76 is mounted on a side surface of the tilt block 74 via a mounting plate 92. A motor (not shown) is housed in the spindle casing 76, and the cup-type grindstone 56 is attached to a spindle 94 of the motor. Therefore, the cup-type grindstone 56 is rotated by the motor.

Incidentally, the spindle casing 76
Are attached to the tilt block 74 by a plurality of bolts 96. The bolt 96 is
It is loosely inserted into a through hole 93 formed in the mounting plate 92 and fastened to the tilt block 74. A disc spring 98 is interposed between the head 97 of the bolt 96 and the mounting plate 92. The spindle casing 76 is urged away from the tilt block 74 by the urging force of the disc spring 98.

The spindle casing 76 is swingably supported by the tilt block 74 via a joint bar 82. The joint bar 82 is formed in a columnar shape, and is formed in the Y-direction on a V-shaped groove 100 formed in the side surface of the tilt block 74 in the Y direction and on the side surface of the mounting plate 92 facing the groove 100. V-shaped groove 1
02 in the Y direction. Therefore, the spindle casing 76 can swing with respect to the tilt block 74 in the circumferential direction of the joint bar 82, that is, in the X direction.

The spindle casing 76 is swung by a spacer driving device 80. The spacer driving device 80 includes a motor 104, a screw rod 106, a spacer 10
8 and a pushing member 110. The motor 1
04 is fixed to the upper surface of the tilt block 74,
The screw rod 106 is connected to the spindle of the motor 104. The screw rod 106 is inserted through a through-hole 112 formed in the tilt block 74, and the spacer 108 is screwed to a tip end thereof. This spacer 1
08 has a substantially wedge-shaped cross section, and the pressing member 110 is pressed against the tapered surface 109 of the tapered surface.
The pushing member 110 is a ball or a columnar member, and is disposed in a V-shaped groove 114 formed on a side surface of the mounting member 92. Therefore, when the motor 104 is driven to rotate the screw rod 106, the spacer 108 moves up and down, so that the pushing member 110 is pushed against the tapered surface 109. Accordingly, the spindle casing 76 swings in the X direction using the peripheral surface of the joint bar 82 as a guide surface. The spindle casing 76 is attached to the tilt block 74 with bolts 96,
The pivot between the spindle casing 76 and the through hole 93 allows the spindle casing 76 to swing.

Next, a method of adjusting the inclination angle of the spindle of the rough grinding stage 18 configured as described above will be described. First, when adjusting the inclination angle in the Y direction, when the motor 86 of the feed screw device 78 is driven, the convex portion 75 is screwed by the screw bar 88 and the convex portion 75 as shown in FIG. The tilt block 74 moves forward and backward with respect to the motor 86, and swings in the Y direction with the pin 84 as a fulcrum. The swing angle of the tilt block 74 is checked with a goniometer, and the motor 86 is stopped when the tilt block inclines to the set angle. Thereby, the inclination angle in the Y direction is adjusted.

Next, when adjusting the tilt angle in the X direction, the motor 104 of the spacer driving device 80 shown in FIG.
Is driven, the spacer 108 moves up and down, so that the spindle casing 76 is pushed by the spacer 108 via the pushing member 110, and the joint bar 8
2 swings in the X direction using the peripheral surface as a guide surface. The swing angle of the spindle casing 76 is checked with a goniometer, and the motor 104 is stopped when the spindle casing 76 is inclined to the set angle. Thus, the inclination angle in the X direction is adjusted, and the adjustment of the inclination angle of the spindle 94 is completed.

Thereafter, the feed table 72 is moved downward to press the cup-shaped grindstone 56 against the wafer 26, and the cup-shaped grindstone 56 and the wafer 26 are rotated to grind the back surface of the wafer 26. As described above, in the present embodiment, the tilt angle in the Y direction is adjusted by the feed screw device 78, and the tilt angle in the X direction is adjusted by using the spacer 108 having a wedge-shaped cross section and the joint bar 82. Compared with a conventional mechanism that adjusts the tilt angle by loosening or closing the adjustment bolt, the tilt angle can be adjusted without any trouble. Also, since the inclination angle is adjusted by the motors 86 and 104, the motor 86
By controlling 104, fine adjustment of the tilt angle can be easily performed.

In the present embodiment, the tilt block 74 is swingably supported in the Y direction with respect to the feed table 72, and the spindle casing 76 is swingably supported in the X direction with respect to the tilt block 74. However, it is not limited to this. For example, the tilt block 74 may be supported swingably in the X direction with respect to the feed table 72, and the spindle casing 76 may be supported swingably in the Y direction with respect to the tilt block 74.

In this embodiment, the spindle tilt angle adjusting mechanism of the surface grinding device for grinding the back surface of the wafer has been described. However, a CMP device for processing a wafer using a polishing cloth instead of a cup-type grindstone, The spindle tilt angle adjusting mechanism of the present invention may be applied to a dicing apparatus that cuts a wafer into dice using a blade instead of a cup-type grindstone.

[0032]

As described above, according to the spindle tilt angle adjusting mechanism of the flattening apparatus according to the present invention, the wedge-shaped spacer member is formed by the driving unit in the gap between the X-direction oscillating portion and the Y-direction oscillating portion. By simply inserting the spindle, the inclination angle of the spindle can be adjusted. Further, according to the present invention, fine adjustment of the tilt angle can be performed only by controlling the amount of insertion of the spacer member by the driving unit.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a surface grinding apparatus for a semiconductor wafer according to an embodiment of the present invention.

FIG. 2 is a plan view of the surface grinding apparatus shown in FIG. 1;

FIG. 3 is a side view including a partial cross section showing the structure of a tilt angle adjusting mechanism of the grinding stage.

FIG. 4 is a perspective view showing the structure of a Y-direction oscillating portion of the tilt angle adjusting mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Surface grinding device 18 ... Rough grinding stage 20 ... Finish grinding stage 26 ... Wafer 56, 64 ... Cup type grindstone 70 ... Casing 72 ... Feed table 74 ... Tilt block 76 ... Spindle casing 78 ... Feed screw device 80 ... Spacer drive 82 Joint bar

Claims (1)

[Claims] 1. An apparatus main body, a table rotatably provided on the apparatus main body and holding a wafer, a casing provided with an elevating device provided side by side with the table, and a Z vertically moved by an elevating device of the casing. A direction moving unit; a Y direction swing unit supported by the Z direction moving unit so as to be swingable in a Y direction orthogonal to the Z direction; A Y-direction oscillating means for oscillating, a whetstone or a polishing cloth spindle supported on the Y-direction oscillating portion so as to be oscillatable in an X direction orthogonal to the Y direction and the Z direction, and for processing the wafer. An X-direction oscillating portion provided with a motor for rotating the spindle; and X-direction oscillating means for oscillating the X-direction oscillating portion in the X-direction with respect to the Y-direction oscillating portion; Swing the swinging part and the X-direction swinging part A flat processing apparatus that adjusts the inclination angle of a spindle with respect to a wafer, moves a grindstone or a polishing cloth downward at a Z-direction moving unit, presses the wafer against the wafer, and rotates the grindstone or the polishing cloth and the wafer to process the wafer. In the above, the X-direction oscillating portion is swingably supported by the Y-direction oscillating portion via a columnar joint member, and the X-direction oscillating means includes a substantially wedge-shaped spacer member and the spacer. A driving unit configured to fit the member into the gap between the X-direction oscillating unit and the Y-direction oscillating unit and to oscillate the X-direction oscillating unit. The driving unit controls the amount of insertion of the spacer member. A tilt angle adjusting mechanism for a flat surface machining apparatus, which controls a swing angle of an X-direction swing unit.