JP7312077B2 - Grinding method for plate-shaped work - Google Patents

Description

The present invention relates to a method of grinding a plate-like work.

In the techniques disclosed in Patent Documents 1 and 2, a square plate-shaped workpiece is ground with a grinding wheel.

JP 2016-150421 A JP 2015-205358 A

The grinding wheel is arranged in a ring on the base, and grinds the upper surface of the rectangular plate-shaped workpiece held on the rotating chuck table. At this time, the grinding wheel is in contact with an area extending from the center to the outer periphery of the rotating rectangular plate-shaped work. Therefore, during grinding, the length (grinding distance) of the portion of the grinding wheel that comes into contact with the square plate-like workpiece increases or decreases. That is, for example, when the diagonal peripheral portion of the rectangular plate-like workpiece is ground, the grinding distance is increased. On the other hand, when grinding the peripheral portion of the line connecting the centers of the opposing sides of the square plate-shaped workpiece, the grinding distance is shortened.

When the grinding distance is shortened, the load applied to the grinding wheel is reduced, so the grinding force is increased and the grinding is facilitated. Therefore, it becomes easy to make the portion to be ground of the rectangular plate-like work a preset predetermined thickness. On the other hand, when the grinding distance is long, the load applied to the grinding wheel is large, so the grinding force is low and it becomes difficult to grind. For this reason, the portion to be ground of the rectangular plate-like work tends to become thicker than the predetermined thickness.

As described above, since the grinding force changes according to the length of the grinding distance during grinding, the thickness of the ground square plate-shaped work varies according to such changes.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the thickness difference that occurs in a square plate-shaped workpiece after grinding when grinding a square plate-shaped workpiece (for example, a rectangular plate-shaped workpiece).

A plate-like workpiece grinding method (this grinding method) according to the present invention comprises: a holding surface holding a polygonal plate-like workpiece; a chuck table rotating about the center of the holding surface; Grinding means for grinding a plate-like workpiece held on a table; Grinding feeding means for moving the grinding means in a direction perpendicular to the holding surface; and horizontal movement means for moving in a parallel horizontal direction, wherein the grinding wheel moves from the center to the outer periphery of the plate-like work held by the chuck table and rotated. using the horizontal movement means to position the axis of the chuck table at a horizontal position through which the lower surface of the grinding wheel passes; Grinding means is fed in a direction approaching the chuck table, and the entire upper surface of the plate-shaped work held on the holding surface of the rotating chuck table is ground by the grinding wheel until it reaches a predetermined thickness , A grinding step of grinding while changing the grinding distance, which is the length of the portion of the grinding wheel that contacts the plate-shaped work, and after the grinding step, stopping the grinding feed by the grinding feed means and using the horizontal movement means. Then, the grinding means and the chuck table are relatively moved horizontally so that the grinding wheel in contact with the upper surface of the plate-like work moves from the shaft of the chuck table toward the outer periphery of the chuck table. an escaping step of separating the grinding wheel from the plate-like work while reducing the thickness difference caused by the difference in the grinding distance by scraping off a thick portion of the plate-like work after the grinding step; including.

In the present grinding method, in the escape process performed after the grinding process, the grinding wheel and the plate-like work are relatively moved horizontally to separate the grinding wheel from the plate-like work. That is, the grinding wheel and the plate-shaped work, which are rotating while being in contact with each other in the grinding process, are relatively moved horizontally while being kept in contact with each other.

Therefore, in the present grinding method, even if there is a thickness variation (thickness difference) in the plate-shaped work after grinding immediately after the grinding process, the horizontal movement of the grinding wheel and the plate-shaped work in the escape process A thick portion of the plate-shaped work can be scraped off with a grinding wheel. Thereby, the difference in thickness of the plate-shaped work can be reduced.

It is an explanatory view showing composition of a grinding device. It is an explanatory view showing the configuration of the grinding device from the side. It is explanatory drawing which shows the cutting process in a grinding device. It is explanatory drawing which shows the escape process in a grinding device. It is explanatory drawing which shows the thickness difference formed in the rectangular workpiece|work immediately after a grinding process. FIG. 11 is an explanatory diagram showing a rectangular workpiece after an escaping process; It is explanatory drawing which shows the thickness difference formed in the rectangular workpiece|work immediately after a grinding process. FIG. 11 is an explanatory diagram showing a rectangular workpiece after an escaping process;

As shown in FIG. 1, a grinding device 11 according to the present embodiment is a device for grinding a rectangular work W as a polygonal plate-like work, and includes a rectangular parallelepiped base 12, an upwardly extending column 13, A control means 70 for controlling each member of the grinding device 11 is provided.

An opening 12 a is provided on the upper surface side of the base 12 . A holding means 15 is arranged in the opening 12a. The holding means 15 includes a chuck table 18 having a holding surface 19 for sucking the rectangular workpiece W, and a support member 16 for supporting the chuck table 18 .

A holding surface 19 of the chuck table 18 communicates with a suction source (not shown) and holds the rectangular workpiece W through the protective tape T by suction. That is, the holding means 15 holds the rectangular workpiece W by the holding surface 19. The holding surface 19 has a gently inclined conical shape with the apex at the center, and the rectangular workpiece W is also held along the holding surface 19. It is held conically (see FIG. 2).

Further, as shown in FIG. 1, the chuck table 18 is rotated in the Z-axis direction passing through the center of the holding surface 19 while holding the rectangular workpiece W by the holding surface 19 by means of the rotating means M arranged in the support member 16 . It is rotatable around a central axis 18b (see FIG. 3) extending to the center. Therefore, the rectangular workpiece W is held by the holding surface 19 and rotated about its center.

A bellows cover J that expands and contracts in the Y-axis direction is connected around the chuck table 18 . A Y-axis direction moving means 40 is arranged below the holding means 15 .

The Y-axis direction moving means 40 is an example of horizontal moving means. The Y-axis direction moving means 40 relatively moves the holding means 15 and the grinding means 30 in a horizontal direction parallel to the holding surface 19 . The Y-axis moving means 40 includes a pair of Y-axis guide rails 42 parallel to the Y-axis direction, a Y-axis moving table 45 sliding on the Y-axis guide rails 42, and a Y-axis ball screw 43 parallel to the Y-axis guide rails 42. , a Y-axis servomotor 44 connected to the Y-axis ball screw 43, a Y-axis encoder 46 for detecting the rotation speed and position of the Y-axis servomotor 44, and a holding table 41 for holding them. there is

The Y-axis moving table 45 is slidably installed on the Y-axis guide rail 42 . A nut portion 45 a (see FIG. 2) is fixed to the lower surface of the Y-axis moving table 45 . The Y-axis ball screw 43 is screwed into the nut portion 45a. The Y-axis servomotor 44 is connected to one end of the Y-axis ball screw 43 .

As shown in FIG. 1 , in the Y-axis direction moving means 40 , the Y-axis servo motor 44 rotates the Y-axis ball screw 43 to move the Y-axis moving table 45 along the Y-axis guide rail 42 in the Y-axis direction. move to A support member 16 of the holding means 15 is placed on the Y-axis moving table 45 . Therefore, as the Y-axis moving table 45 moves in the Y-axis direction, the holding means 15 including the chuck table 18 moves in the Y-axis direction.

In addition, as shown in FIG. 2, the support member 16 is mounted on the Y-axis moving table 45 via the tilt changing member 17 . The inclination changing member 17 is used to change the inclination of the holding surface 19 of the chuck table 18 in the holding means 15 .

In this embodiment, roughly speaking, the holding means 15 has a front (−Y direction side) wafer placement position for placing the rectangular work W on the holding surface 19 and a rear wafer placement position where the rectangular work W is ground. It moves along the Y-axis direction between the (+Y-direction side) grinding areas.

Further, as shown in FIG. 1, a column 13 is erected behind the base 12 (on the +Y direction side). A grinding means 30 for grinding the rectangular workpiece W and a grinding feeding means 14 for moving the grinding means 30 in the Z-axis direction (grinding feeding direction) perpendicular to the holding surface 19 are provided on the front surface of the column 13 .

The grinding feed means 14 includes a pair of Z-axis guide rails 21 parallel to the Z-axis direction, a Z-axis moving table 23 sliding on the Z-axis guide rails 21, a Z-axis ball screw 20 parallel to the Z-axis guide rails 21, a Z Axis servomotor 22 , Z-axis encoder 25 for detecting the rotation speed and position of Z-axis servomotor 22 , and holder 24 attached to the front surface (surface) of Z-axis moving table 23 are provided. The holder 24 holds grinding means 30 .

The Z-axis moving table 23 is slidably installed on the Z-axis guide rail 21 . A nut portion 20 a (see FIG. 2 ) is fixed to the rear surface side (rear surface side) of the Z-axis moving table 23 . A Z-axis ball screw 20 is screwed into the nut portion 20a. The Z-axis servomotor 22 is connected to one end of the Z-axis ball screw 20 .

As shown in FIG. 1, in the grinding feeding means 14, the Z-axis servomotor 22 rotates the Z-axis ball screw 20 to move the Z-axis moving table 23 along the Z-axis guide rail 21 in the Z-axis direction. do. As a result, the holder 24 attached to the Z-axis moving table 23 and the grinding means 30 held by the holder 24 move together with the Z-axis moving table 23 in the Z-axis direction.

The grinding means 30 includes a spindle housing 31 fixed to the holder 24, a spindle 32 rotatably held by the spindle housing 31, a motor 33 for rotating the spindle 32, a wheel mount 34 attached to the lower end of the spindle 32, and , a grinding wheel 35 supported on a wheel mount 34 .

The spindle housing 31 is held by the holder 24 so as to extend in the Z-axis direction. The spindle 32 extends in the Z-axis direction perpendicular to the holding surface 19 of the chuck table 18 and is rotatably supported by the spindle housing 31 .

The motor 33 is connected to the upper end side of the spindle 32 . The motor 33 causes the spindle 32 to rotate around a rotation axis extending in the Z-axis direction.

The wheel mount 34 is disc-shaped and fixed to the lower end (tip) of the spindle 32 . A wheel mount 34 supports a grinding wheel 35 .

Grinding wheel 35 is formed to have approximately the same diameter as wheel mount 34 . The grinding wheel 35 includes an annular wheel base (annular base) 36 made of a metal material such as stainless steel. A plurality of annularly arranged grinding wheels 37 are fixed to the lower surface of the wheel base 36 over the entire circumference. The grinding wheel 37 grinds the upper surface of the rectangular workpiece W held on the holding surface 19 of the chuck table 18 in the holding means 15 arranged in the grinding area.
The surface to be ground of the rectangular work W may be the pattern surface for forming the device or the back surface opposite to the pattern surface.

In this way, the grinding means 30 holds the rectangular workpiece W on the holding surface 19 of the chuck table 18 in the holding means 15 and rotates about the center of the holding surface 19, and the rotating grinding wheel 35 is provided with the workpiece W. Grind by an annular grinding wheel 37 .
During grinding, the inclination of the chuck table 18 is adjusted by the inclination changing member 17 so that the upper surface of the conical rectangular workpiece W is parallel to the grinding wheel 37, as shown in FIG.

The control means 70 controls each member of the grinding device 11 to grind the rectangular workpiece W. As shown in FIG. The grinding process in the grinding device 11 will be described below.

First, the control means 70 or an operator holds the rectangular workpiece W on the holding surface 19 of the chuck table 18 of the holding means 15 shown in FIG. The control means 70 then controls the motor 33 to rotate the grinding wheel 35 (grinding stone 37) together with the spindle 32, as indicated by arrow A in FIG.
Furthermore, the control means 70 rotates the chuck table 18 by the rotation means M arranged inside the support member 16 . As a result, the chuck table 18 and the rectangular workpiece W held on its holding surface 19 are rotated as indicated by the arrow B. As shown in FIG.

Next, the control means 70 implements a grinding process. In this process, first, the control means 70 uses the Y-axis direction moving means 40 to move the center (rotational position) of the rectangular work W held on the holding surface 19 of the chuck table 18 of the holding means 15 as shown in FIG. center) at a horizontal position in the grinding means 30 through which the lower surface of the grinding wheel 37 passes. That is, the grinding wheel 37 (the lower surface of the grinding wheel 37) is arranged at the center of the rectangular workpiece W held on the holding surface 19. As shown in FIG.

Further, the control means 70 uses the grinding feed means 14 to feed the grinding means 30 including the grinding wheel 37 in the direction (-Z direction) approaching the chuck table 18 as indicated by the arrow C in FIG. do. In this manner, the control means 70 grinds the rectangular workpiece W held on the holding surface 19 of the rotating chuck table 18 by the grinding wheel 37 until it reaches a preset thickness.

In the grinding process, the thickness of the rectangular workpiece W being ground is appropriately measured by thickness measuring means (not shown). 3 and 4, the grinding feeding means 14 and the grinding means 30 are shown in a simplified manner.

After the grinding process, the control means 70 carries out an escaping process. In the escape process, the control means 70 stops the grinding feeding of the grinding means 30 by the grinding feeding means 14 . After that, while the grinding wheel 37 and the chuck table 18 are being rotated, the control means 70 uses the Y-axis direction moving means 40 (see FIGS. 1 and 2) to move the grinding wheel 37 of the grinding means 30 to the chuck table. The grinding wheel 37 and the chuck table 18 are relatively moved horizontally so as to move from the center of rotation (center axis 18 b ) of the chuck table 18 toward the outer circumference of the chuck table 18 . In the present embodiment, the grinding wheel 37 and the chuck table 18 are relatively horizontally moved from the center 18a (see FIG. 3) of the rotating rectangular workpiece W toward the outer circumference of the rectangular workpiece W. Further, in this embodiment, the Y-axis direction moving means 40 moves the chuck table 18 (holding means 15) in the -Y direction as indicated by arrow D in FIG. In this manner, the control means 70 separates the grinding wheel 37 from the rectangular workpiece W, as shown in FIG.

As described above, in the present embodiment, the grinding wheel 37 is separated from the rectangular workpiece W by relatively moving the grinding wheel 37 and the rectangular workpiece W in the horizontal direction in the escape process performed after the grinding process. I am letting That is, the grinding wheel 37 and the rectangular workpiece W, which are rotating while being in contact with each other in the grinding process, are relatively moved horizontally while being kept in contact with each other.

Therefore, even if there is a thickness variation (thickness difference) in the rectangular workpiece W after grinding immediately after the grinding process, the horizontal movement of the grinding wheel 37 and the rectangular workpiece W in the escaping process will cause the rectangular workpiece W to move. A thick portion can be scraped off by the grinding wheel 37 . Thereby, the difference in thickness of the rectangular workpiece W can be reduced.

That is, when the peripheral portion of the line connecting the centers of the opposing sides of the rectangular workpiece W is ground, the grinding distance is shortened, the load applied to the grinding wheel 37 is reduced, and the portion to be ground is reduced to a predetermined thickness. easier to do. On the other hand, when the diagonal peripheral portion of the rectangular workpiece W is ground, the grinding distance becomes longer, the load applied to the grinding wheel 37 becomes larger, and the portion to be ground tends to become thicker. Therefore, immediately after the grinding process, the rectangular workpiece W may have a thickness difference as shown in FIG.

In this regard, in the present embodiment, the escape process described above is performed, and the thick portion of the rectangular workpiece W is scraped off by the grinding wheel 37 that moves horizontally relative to the rectangular workpiece W. As shown in FIG. This makes it possible to reduce the thickness difference in the rectangular workpiece W, as shown in FIG.

In this embodiment, one rectangular workpiece W is held on the holding surface 19 of the chuck table 18 . In this regard, a plurality of (for example, two) rectangular works W may be placed on the holding surface 19 and ground at the same time.

Even in this case, as shown in FIG. 7, there may be a thickness difference between the rectangular workpiece W1 and the rectangular workpiece W2 immediately after the grinding process. By performing the escape process described above, the thickness difference between the rectangular workpiece W1 and the rectangular workpiece W2 can be reduced as shown in FIG.

11: grinding device, 12: base, 13: column,
15: holding means, 18: chuck table, 19: holding surface,
14: Grinding feeding means,
30: grinding means, 32: spindle, 33: motor, 37: grinding wheel,
40: Y-axis moving means,
70: control means,
W: Rectangular work, W1: Rectangular work, W2: Rectangular work

Claims (1)

A chuck table that holds a polygonal plate-like work by a holding surface and rotates around the center of the holding surface; grinding means that grinds the plate-like work held on the chuck table with an annular grinding wheel; A grinding apparatus comprising grinding feed means for moving the grinding means in a direction perpendicular to the holding surface, and horizontal movement means for relatively moving the grinding means and the chuck table in a horizontal direction parallel to the holding surface. A method for grinding a plate-like workpiece using
The grinding wheel is capable of contacting an area extending from the center to the outer periphery of the plate-like workpiece that is held and rotated by the chuck table,
The horizontal movement means is used to position the shaft of the chuck table at a horizontal position through which the lower surface of the grinding wheel passes, and the grinding feed means is used to move the grinding means in a direction approaching the chuck table. , and the entire upper surface of the plate-like work held on the holding surface of the rotating chuck table is brought into contact with the plate-like work on the grinding wheel by the grinding wheel until it reaches a predetermined thickness. A grinding step of grinding while changing the grinding distance, which is the length of the part ;
After the grinding step, the grinding feed by the grinding feed means is stopped, and the horizontal movement means is used to move the grinding wheel in contact with the upper surface of the plate-like work from the shaft of the chuck table to the chuck table. By relatively moving the grinding means and the chuck table in the horizontal direction toward the outer periphery of the plate-shaped workpiece after the grinding step, a thick portion of the plate-shaped workpiece is scraped off, resulting in a difference in the grinding distance. an escaping step of separating the grinding wheel from the plate-shaped work while reducing the thickness difference ;
A method of grinding a plate-shaped work including

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