JP7096752B2 - Grinding device - Google Patents

Description

The present invention relates to a grinding device.

In a grinding device for grinding a plate-shaped workpiece, a grinding wheel having a grinding wheel arranged in an annular shape is attached to a mount connected to the tip of a spindle. Then, the plate-shaped work held on the holding table is ground by the grinding wheel that rotates together with the spindle. Grinding water is supplied to the inner surface of the grinding wheel to remove grinding debris and grinding heat generated in the grinding process.

Patent Documents 1 and 2 disclose a nozzle that sprays grinding water onto the inner peripheral surface of a grinding wheel.

Japanese Unexamined Patent Publication No. 2015-196226 Japanese Unexamined Patent Publication No. 7-223152

In the techniques of Patent Documents 1 and 2, the grinding wheel protrudes from the plate-shaped work in order to dispose of such a nozzle. However, if the area of the plate-shaped work is large, the grinding wheel may slightly protrude from the plate-shaped work, and in this case, it is difficult to dispose the nozzle as described above. Therefore, the grinding water is supplied to the grinding wheel through the center of the spindle.

However, in this configuration, the grinding water is affected by the centrifugal force generated by the rotation of the spindle. For example, if the rotation speed of the spindle is too high, the centrifugal force generated in the grinding water becomes large, so that the grinding water is discharged from the grinding wheel before it is sufficiently cooled. On the other hand, if the rotation speed of the spindle is too slow, the centrifugal force generated in the grinding water becomes small, and it is difficult for the grinding water to reach the grinding wheel. Therefore, it becomes difficult to sufficiently remove the grinding debris and the processing heat from the grinding wheel, and there is a problem that the consumption of the grinding wheel increases.

An object of the present invention is to supply the grinding water to an appropriate position of the grinding wheel even if the centrifugal force generated in the grinding water changes, and to reduce the consumption of the grinding wheel.

The grinding device (main grinding device) of the present invention can rotate a grinding wheel having a chuck table for holding a workpiece and a grinding wheel arranged in an annular shape for grinding the workpiece held on the chuck table. A grinding device including a grinding means supporting the grinding wheel, wherein the grinding means includes a wheel mount that supports the grinding wheel, a rotating shaft connected to the center of the wheel mount, and a motor that rotates the rotating shaft. A grinding water supply path that reaches the wheel mount and supplies grinding water is formed inside the rotating shaft, and the wheel mount communicates with the grinding water supply path and is centered on the rotating shaft. A first injection port arranged on the circumference of the first circle having a first radius, and a second having a second radius centered on the rotation axis and larger than the first radius. A second injection port provided on the circumference of the circle is provided, and the injection means has a receiving port that communicates with the grinding water supply path and receives the grinding water. A cylinder in which a first outlet for feeding the grinding water through the first injection port and a second outlet for feeding the grinding water through the second injection port are formed, and an inner diameter of the cylinder. A first sliding valve having the same outer diameter and selectively closing the first outlet, and a second sliding valve having the same outer diameter as the inner diameter of the cylinder and selectively closing the second outlet. A second sliding valve that closes to the cylinder, a piston having the first sliding valve and the second sliding valve at both ends and a connecting bar thinner than the inner diameter of the cylinder, and a piston arranged in the cylinder. The first rotation, which has a spring that urges the piston toward the center of the wheel mount and positions the first sliding valve at the first inlet / outlet, and the rotation speed of the wheel mount is relatively slow. At speed, the first outlet is blocked by the first sliding valve, and the grinding water received at the inlet is through the connecting bar and the second outlet. When the rotation speed of the wheel mount is the second rotation speed, which is guided by the injection port of the wheel mount, the piston moves to the outer peripheral side of the wheel mount against the urging force of the spring, and the second rotation speed is relatively high. The outlet is closed by the second sliding valve, and the grinding water received in the inlet is guided to the first injection port through the connecting bar and the first outlet.

In this grinding device, a plurality of the injection means may be arranged at an equal angle around the center of the wheel mount.
Further, the grinding device may further include an adjusting unit for adjusting the urging force of the spring.

In a grinding device such as this grinding device, the faster the rotation speed of the wheel mount and the farther the injection site of the grinding water is from the center of the wheel mount, the more the grinding water tries to fly relatively far from the injection site. do. Further, the slower the rotation speed of the wheel mount and the closer the injection portion of the grinding water is to the center of the wheel mount, the closer the grinding water tends to fly closer to the injection portion. Therefore, the landing position of the grinding water may deviate from the appropriate range.

Therefore, in this grinding device, when the rotation speed is slow, the grinding water is injected from the second injection port far from the center of the wheel mount, while when the rotation speed is high, the first one near the center of the wheel mount. Grinding water is sprayed from the injection port of. As a result, the grinding water can be landed in an appropriate range, and a large amount of grinding water can be supplied to the place where the workpiece and the grinding wheel come into contact with each other. As a result, it becomes possible to satisfactorily cool the grinding wheel and remove the grinding debris, so that the consumption of the grinding wheel can be reduced.

Further, when a plurality of injection means are arranged at an equal angle around the center of the wheel mount, the grinding water can be evenly injected onto the workpiece by the plurality of injection ports, so that the grinding wheel can be used. Cooling and removal of grinding debris can be performed better.

As described above, the second rotation speed is such that the second inlet is blocked by the second sliding valve. This second rotational speed is determined by the centrifugal force applied to the piston at this speed and the urging force of the spring. Therefore, when the grinding device further includes an adjusting unit for adjusting the urging force of the spring, the user can adjust the urging force of the spring by using, for example, the adjusting unit to adjust the second rotational speed. Can be adjusted.

It is a perspective view which shows the structural example of the grinding apparatus provided with the wheel mount which concerns on this embodiment. It is explanatory drawing which shows the grinding water supply system in the grinding apparatus shown in FIG. It is a perspective view which shows the wheel mounting surface of a wheel mount. It is explanatory drawing which shows the structure of the mount flow path in the wheel mount shown in FIG. It is explanatory drawing which shows the structure of the mount flow path above the aa line shown in FIG. It is explanatory drawing which shows the structure of the mount flow path below the cc line shown in FIG. It is explanatory drawing which shows the structure of the mount flow path in the cross section in the cross section in line bb shown in FIG. It is explanatory drawing which shows the structure of a piston. It is explanatory drawing which shows the position of a piston when the rotation speed of a wheel mount is the first rotation speed which is relatively slow. It is explanatory drawing which shows the position of a piston and the flow path of the grinding water when the rotation speed of a wheel mount is the second rotation speed which is relatively fast. It is explanatory drawing which shows the modification of the wheel mount.

As shown in FIG. 1, the grinding apparatus 2 according to the present embodiment includes a rectangular parallelepiped base 4, a support column 6 extending upward, and a grinding water supply source 46 for supplying grinding water.

On the front side of the upper surface of the base 4, the chuck table portion 8 including the chuck table 12, the X-axis moving mechanism (not shown) for moving the chuck table portion 8 in the X-axis direction, and the waterproof cover covering the X-axis moving mechanism are covered. 10 is arranged.

The X-axis moving mechanism is provided in the rectangular opening 5 extending in the X-axis direction (front-back direction). The X-axis movement mechanism includes a pair of X-axis guide rails parallel to the X-axis direction, an X-axis ball screw parallel to the X-axis guide rail, and a nut portion and an X-axis pulse motor connected to the X-axis ball screw. Yes (not shown at all).

On the X-axis guide rail, the X-axis moving table 11 of the chuck table portion 8 is slidably installed. The nut portion is fixed to the lower surface side of the X-axis moving table 11. An X-axis ball screw is screwed into this nut portion. The X-axis pulse motor is connected to one end of the X-axis ball screw.
In the X-axis movement mechanism, the X-axis movement table 11 moves in the X-axis direction along the X-axis guide rail by rotating the X-axis ball screw by the X-axis pulse motor.

The chuck table unit 8 includes a chuck table 12 that holds a wafer 1 (see FIG. 2) that is a workpiece, and the above-mentioned X-axis moving table 11 that holds the chuck table 12. The chuck table 12 is arranged on the upper surface of the X-axis moving table 11, and moves along the X-axis together with the chuck table 12 by the X-axis moving mechanism. In the present embodiment, the X-axis moving table 11 and the chuck table 12 move between the front loading / unloading position where the wafer 1 is carried in and out and the rear grinding position where the wafer 1 is ground.

The chuck table 12 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis extending in the Z-axis direction (vertical direction). The chuck table 12 has a holding surface 13 for sucking and holding the wafer 1 in the center of the upper surface thereof. The holding surface 13 is formed on a conical surface. This conical surface has an extremely gentle inclination with the center of rotation of the chuck table 12 as the apex. The holding surface 13 is communicated with a suction source (not shown), and as shown in FIG. 2, the wafer 1 is sucked and held so that the surface to be ground 1a is exposed.

As shown in FIG. 1, the support pillar 6 is erected at the rear part of the base 4. A grinding means 26 for grinding the wafer 1 and a Z-axis moving mechanism 16 for moving the grinding means 26 in the Z-axis direction are provided on the front surface of the support column 6.

The Z-axis moving mechanism 16 includes a pair of Z-axis guide rails 18 parallel to the Z-axis direction, a Z-axis moving table 20 sliding on the Z-axis guide rail 18, and a Z-axis ball screw 22 parallel to the Z-axis guide rail 18. It also includes a nut portion (not shown) connected to the Z-axis ball screw 22 and a Z-axis pulse motor 24.

The Z-axis moving table 20 is slidably installed on the Z-axis guide rail 18. A nut portion (not shown) is fixed to the rear surface side (rear surface side) of the Z-axis moving table 20. A Z-axis ball screw 22 is screwed into this nut portion. The Z-axis pulse motor 24 is connected to one end of the Z-axis ball screw 22.
In the Z-axis moving mechanism 16, the Z-axis moving table 20 moves in the Z-axis direction along the Z-axis guide rail 18 by rotating the Z-axis ball screw 22 by the Z-axis pulse motor 24.

The grinding means 26 is attached to the front surface (surface) of the Z-axis moving table 20. The grinding means 26 is provided at the support structure 28 fixed to the Z-axis movement table 20 of the Z-axis movement mechanism 16, the spindle housing 30 fixed to the support structure 28, the spindle 32 held by the spindle housing 30, and the lower end of the spindle 32. It includes a mounted wheel mount 34 and a grinding wheel 36 supported by the wheel mount 34. The grinding means 26 rotatably supports the grinding wheel 36.

The support structure 28 is attached to the Z-axis movement table 20 of the Z-axis movement mechanism 16 in a state of supporting other members of the grinding means 26. The spindle housing 30 is held by the support structure 28 so as to extend in the Z-axis direction. The spindle 32 is a rotating shaft provided in the grinding means 26. The spindle 32 is rotatably supported by the spindle housing 30 so as to extend in the Z-axis direction. A rotary drive source (not shown) such as a motor is connected to the upper end side of the spindle 32. With this rotational drive source, the spindle 32 rotates around a rotation axis extending in the Z-axis direction.

The wheel mount 34 is formed in a disk shape and is fixed to the lower end (tip) of the spindle 32. As shown in FIG. 2, the wheel mount 34 has a spindle mounting surface 34a. The wheel mount 34 is mounted on the tip of the spindle 32 via the spindle mounting surface 34a. In this way, the spindle 32 is connected to the center of the wheel mount 34.
Further, the wheel mount 34 has a wheel mounting surface 34b that is opposite to the spindle mounting surface 34a. The grinding wheel 36 is mounted on the wheel mounting surface 34b. The wheel mounting surface 34b allows the wheel mount 34 to support the grinding wheel 36.

The grinding wheel 36 is formed so as to have substantially the same diameter as the wheel mount 34. As shown in FIG. 2, the grinding wheel 36 includes an annular wheel base (annular base) 38 formed of a metal material such as stainless steel. A plurality of grinding wheels 40 arranged in an annular shape are fixed to the lower surface of the wheel base 38 over the entire circumference. The grinding wheel 40 grinds the wafer 1 held on the chuck table 12.

The grinding device 2 includes a grinding water supply system for supplying grinding water to the surface to be ground 1a of the wafer 1 and the grinding wheel 40. As shown in FIG. 2, the grinding water supply system includes a grinding water supply source 46 which is a water source of the grinding device 2, a supply pipe 42 extending from the grinding water supply source 46, and a grinding water supply path 33 formed in a spindle 32. It also includes a mount flow path 35 formed within the wheel mount 34.

The supply pipe 42 supplies the grinding water from the grinding water supply source 46 to the grinding water supply path 33 of the spindle 32. The grinding water supply path 33 is provided so as to pass through the center of the spindle 32 and reach the wheel mount 34. The grinding water supply path 33 carries the grinding water supplied through the supply pipe 42 to the mount flow path 35 of the wheel mount 34. The grinding water is supplied to the surface to be ground 1a of the wafer 1 and the grinding wheel 40 via the mount flow path 35. The supply and stop of grinding water is controlled, for example, by a controller (not shown).

The configuration of the wheel mount 34 including the mount flow path 35 will be described below.
As shown in FIG. 3, the wheel mounting surface 34b of the wheel mount 34 is provided with a grinding wheel mounting screw hole 111 provided on the outermost circumference and a wheel mount mounting hole 113 provided on the inner peripheral side thereof. Has been done.
The grinding wheel mounting screw hole 111 is used to screw the wheel base 38 of the grinding wheel 36 to the wheel mount 34. The wheel mount mounting hole 113 is used to screw the wheel mount 34 to the spindle 32.

As shown in FIGS. 3 and 4, the mount flow path 35 includes a connection port 51 provided on the spindle mounting surface 34a side, a grinding water receiving path 52, and a first injection port 53 provided on the wheel mounting surface 34b. Includes a second injection port 55, a first annular groove 65 and a second annular groove 67, a cylinder 71 provided inside the wheel mount 34, a first connecting path 57 and a second connecting path 59. I'm out. A piston 81 and a spring 91 are arranged in the cylinder 71.

The first annular groove 65 and the second annular groove 67 are provided on the wheel mounting surface 34b so as to be centered on the center of the wheel mounting surface 34b. The radius of the second annular groove 67 is longer than the radius of the first annular groove 65.

The first injection port 53 is arranged in the first annular groove 65. The first injection port 53 is arranged on the circumference of a first circle having a first radius with the spindle 32 (center of the spindle 32 and the wheel mounting surface 34b) as the center of rotation. On the other hand, the second injection port 55 is arranged in the second annular groove 67. The second injection port 55 is arranged around the spindle 32 on the circumference of a second circle having a second radius larger than the first radius.

As shown in FIGS. 4 and 5, the connection port 51 is formed at the center of the spindle mounting surface 34a and is connected to the grinding water supply path 33 of the spindle 32. Four grinding water receiving paths 52 are connected to the connecting port 51 at an angle interval of, for example, approximately 90 degrees. Each grinding water receiving path 52 is formed so as to extend from the connection port 51 toward the radial outer side of the wheel mount 34 substantially parallel to the wheel mounting surface 34b.

As shown in FIGS. 4 and 6, the cylinder 71 extends in the radial direction of the wheel mount 34 in parallel with the grinding water receiving path 52 on the lower side (wheel mounting surface 34b side) of the grinding water receiving path 52. It is provided as follows. The cylinder 71 includes one receiving port 73 for grinding water and two outlets 75 and 77 for grinding water.
In FIG. 6, for convenience of explanation, the drawing of the piston 81 and the spring 91 arranged in the cylinder 71 is omitted.

The receiving port 73 is provided on the upper side of the cylinder 71 (on the spindle mounting surface 34a side). The receiving port 73 communicates with the outer end of the grinding water receiving path 52 and receives the grinding water from the grinding water receiving path 52.

The first delivery port 75 and the second delivery port 77 are provided on the lower side (wheel mounting surface 34b side) of the cylinder 71 so as to sandwich the reception port 73. The first delivery port 75 is provided outside the reception port 73. The second delivery port 77 is provided inside the reception port 73.

As shown in FIGS. 4, 6 and 7, the first connection path 57 is formed inside the wheel mount 34 so as to connect the first outlet 75 and the first injection port 53. There is. The first delivery port 75 and the first injection port 53 are formed at positions relatively close to each other in the radial direction of the wheel mount 34. Therefore, the first connecting path 57 is relatively short. In this way, the first outlet 75 communicates with the first injection port 53 via the first connection path 57, and the grinding water is sent out to the first injection port 53. The first injection port 53 communicates with the grinding water receiving path 52 via the receiving port 73, the first feeding port 75, and the first connecting path 57.

The second connection path 59 is formed inside the wheel mount 34 so as to connect the second outlet 77 and the second injection port 55. The second outlet 77 is provided relatively inside, while the second injection port 55 is provided relatively outside. Therefore, as shown in FIG. 6, the second connecting path 59 is relatively long and extends along the radial direction of the wheel mount 34. In this way, the second outlet 77 communicates with the second injection port 55 via the second connecting path 59, and the grinding water is sent out to the second injection port 55. The second injection port 55 communicates with the grinding water receiving path 52 via the receiving port 73, the second feeding port 77, and the second connecting path 59.

As shown in FIG. 8, the piston 81 includes a first sliding valve 83 and a second sliding valve 85 having an outer diameter equal to the inner diameter of the cylinder 71, and a connecting bar 87 connecting them. There is. In addition, in FIG. 8, in order to clearly show the vicinity of the cylinder 71, a part of the configuration shown in FIG. 4 is enlarged and shown.

The first sliding valve 83 is arranged relatively outside in the cylinder 71, and selectively closes the first delivery port 75. The second sliding valve 85 is arranged relatively inward in the cylinder 71, and selectively closes the second delivery port 77. The connecting bar 87 includes a first sliding valve 83 and a second sliding valve 85 at both ends, and is smaller than the inner diameter of the cylinder 71.

The spring 91 is arranged outside the first sliding valve 83 of the piston 81 in the cylinder 71. One end of the spring 91 is connected to the first sliding valve 83, and the other end of the spring 91 is connected to the outer end of the cylinder 71. The spring 91 positions the first sliding valve 83 at the first delivery port 75 by urging the piston 81 inward.

As shown in FIGS. 3, 5, and 6, the wheel mount 34 has a grinding water receiving path 52, a cylinder 71, a piston 81 and a spring 91 in the cylinder 71, a first injection port 53, and a second injection port 53. A plurality (four) portions including one injection port 55 are arranged with the center of the wheel mount 34 as the center and separated by an equal angle (90 degrees) along the circumferential direction. This portion corresponds to an example of the injection means.

Here, the grinding process in the grinding apparatus 2 having the above configuration will be described. First, at the loading / unloading position, the wafer 1 is placed on the holding surface 13 of the chuck table 12 shown in FIG. Then, the suction force generated by the suction source (not shown) is transmitted to the holding surface 13, so that the holding surface 13 sucks and holds the wafer 1 so that the surface 1a to be ground of the wafer 1 is exposed.

After that, the X-axis moving table 11 holding the chuck table 12 moves along the X-axis direction to the bottom of the grinding means 26 by the X-axis moving mechanism. Then, the grinding wheel 36 of the grinding means 26 and the wafer 1 held on the chuck table 12 are aligned in the X-axis direction. This alignment is performed, for example, so that the rotation center of the grinding wheel 36 is displaced by a predetermined distance from the rotation center of the wafer 1 and the rotation locus of the grinding wheel 40 passes through the rotation center of the wafer 1. The inclination of the chuck table 12 is adjusted in advance so that the holding surface 13 is parallel to the grinding surface which is the lower surface of the grinding wheel 40. As a result, the surface to be ground 1a of the wafer 1 becomes parallel to the grinding surface of the grinding wheel 40.

After the alignment of the grinding wheel 36 and the wafer 1 is performed, the spindle 32 is rotationally driven by a rotational drive source (not shown). Along with this, the grinding wheel 36 rotates counterclockwise, for example, when viewed from above. Further, the chuck table 12 holding the wafer 1 is also rotated counterclockwise when viewed from above by a rotation drive source (not shown).

After that, the grinding means 26 is sent downward by the Z-axis moving mechanism 16, and the grinding wheel 36 is lowered accordingly. Then, the grinding wheel 40 comes into contact with the surface to be ground 1a of the wafer 1 to perform the grinding process. In the grinding device 2, both the grinding wheel 40 and the wafer 1 rotate, so that the grinding wheel 40 can grind the entire surface of the wafer 1.

Further, in the grinding apparatus 2, during the grinding process, the grinding water is supplied to the surface to be ground 1a of the wafer 1 and the grinding wheel 40 by the above-mentioned grinding water supply system. The operation of supplying the grinding water in the grinding device 2 will be described below.

The grinding water is stored in the grinding water supply source 46 shown in FIG. When the grinding process is started, a controller (not shown) starts to flow the grinding water of the grinding water supply source 46 into the supply pipe 42. The grinding water is supplied to the grinding water supply path 33 of the spindle 32 via the supply pipe 42. The grinding water supplied to the grinding water supply path 33 is carried to the connection port 51 in the mount flow path 35 of the wheel mount 34 shown in FIG.
In the wheel mount 34, the water carried to the connection port 51 is passed through either the first connection path 57 or the second connection path 59 to any of the first injection port 53 and the second injection port 55. From there, it is injected toward the surface to be ground 1a of the wafer 1.

Here, for example, when the rotation speed of the wheel mount 34 is a relatively slow first rotation speed, the centrifugal force received by the piston 81 becomes relatively small. Therefore, as shown in FIG. 9, the position of the piston 81 urged inward by the urging force of the spring 91 does not change substantially, and the first sliding valve 83 is positioned at the first delivery port 75. It will remain. Therefore, the first delivery port 75 is blocked, and the first connection path 57 following the first outlet 75 is blocked. Therefore, as shown by the arrow F in FIG. 9, the supplied grinding water flows into the second connecting path 59 through the connecting bar 87 and the second delivery port 77 in the cylinder 71, and the second injection is performed. Guided by the port 55, it is ejected from the second injection port 55.

The grinding water injected from the second injection port 55 is guided by the second annular groove 67 along the inner surface thereof and falls on the surface to be ground 1a of the wafer 1 shown in FIG. After that, the grinding water slides on the surface to be ground 1a and is supplied to a place where the surface to be ground 1a and the grinding wheel 40 come into contact with each other.

On the other hand, when the rotation speed of the wheel mount 34 is a relatively high second rotation speed, the centrifugal force received by the piston 81 becomes relatively large. Therefore, as shown in FIG. 10, the piston 81 urged inward by the spring 91 moves outward against the urging force of the spring 91. As a result, the first sliding valve 83 is disengaged from the first delivery port 75, and the second sliding valve 85 is positioned at the second delivery port 77. Therefore, the second outlet 77 is blocked, and the second connecting path 59 following the second outlet 77 is blocked. Therefore, as shown by the arrow N in FIG. 10, the supplied grinding water flows into the first connecting path 57 through the connecting bar 87 in the cylinder 71 and the first delivery port 75, and the first injection is performed. Guided by the port 53, it is ejected from the first injection port 53.

The grinding water injected from the first injection port 53 is guided by the first annular groove 65 along the inner surface thereof and falls on the surface to be ground 1a of the wafer 1. After that, the grinding water slides on the surface to be ground 1a and is supplied to a place where the surface to be ground 1a and the grinding wheel 40 come into contact with each other.

As described above, in the present embodiment, when the rotation speed of the wheel mount 34 is slow, the grinding water is ejected from the second injection port 55 on the outer peripheral side (far from the center), while the rotation speed is high. It is ejected from the inner first injection port 53 (close to the center).

Here, the centrifugal force applied to the grinding water at the time of injection changes depending on the rotation speed of the wheel mount 34 and the injection portion of the grinding water. For example, when the rotation speed of the wheel mount 34 is high, the grinding water in the wheel mount 34 is strong from the wall surface of the grinding water receiving path 52, the cylinder 71, the connecting path 57, 59, etc. before being injected. Receives force (centrifugal force received by grinding water becomes stronger). Further, this force becomes stronger as the injection portion of the grinding water moves away from the center (rotation center) of the wheel mounting surface 34b.

Therefore, the faster the rotation speed of the wheel mount 34 and the farther the injection portion of the grinding water is from the center, the greater the centrifugal force applied to the grinding water, and the more the grinding water tries to fly relatively far from the injection portion. do. Therefore, if the injection portion of the grinding water is far from the center when the rotation speed is high, the landing position of the injected grinding water may deviate from the appropriate range to the outside. For example, it is conceivable that the grinding water does not fall on the surface to be ground 1a but flies to the side of the grinding wheel 40. In this case, a part of the grinding water may leak to the outside through the gap of the grinding wheel 40 and may not be supplied to the portion where the grinding wheel 40 and the surface to be ground 1a come into contact with each other. Alternatively, the grinding water becomes mist due to a large centrifugal force, has no cooling and cleaning effect, and may exceed the grinding wheel 40 and scatter to the surroundings.

On the other hand, when the rotation speed of the wheel mount 34 is slow, the centrifugal force applied to the grinding water in the wheel mount 34 becomes small. Further, this centrifugal force becomes weaker as the injection portion of the grinding water approaches the center of the wheel mounting surface 34b. Therefore, the slower the rotation speed and the closer the injection portion of the grinding water is to the center, the smaller the centrifugal force applied to the grinding water, and the more the grinding water tends to fall relatively close to the injection portion. Therefore, when the rotation speed is slow and the injection portion of the grinding water is close to the center, the landing position of the injected grinding water may deviate inward from the appropriate range. For example, the grinding water may not easily reach the point where the surface to be ground 1a and the grinding wheel 40 come into contact with each other.

In this regard, in the present embodiment, when the rotation speed of the wheel mount 34 is high, the grinding water is injected from the first injection port 53 near the center, while when the rotation speed is slow, the second injection port far from the center is injected. By injecting the grinding water from the injection port 55 of the above, the grinding water can be landed in an appropriate range. Therefore, a large amount of grinding water can be supplied to a portion where the surface to be ground 1a and the grinding wheel 40 come into contact with each other. As a result, the grinding wheel 40 can be cooled and the grinding debris can be removed satisfactorily, so that the consumption of the grinding wheel 40 can be reduced.

Further, the wheel mount 34 has a first annular groove 65 in which the first injection port 53 is arranged centered on the center of the wheel mounting surface 34b, and a second wheel mount 34 centered on the center of the wheel mounting surface 34b. It is provided with a second annular groove 67 in which the injection port 55 of the above is arranged. As a result, the grinding water injected from the first injection port 53 and the second injection port 55 is guided along the inner surface thereof by the first annular groove 65 and the second annular groove 67, respectively. Then, it falls on the surface to be ground 1a. After that, the grinding water slides on the surface to be ground 1a and is supplied to a place where the surface to be ground 1a and the grinding wheel 40 come into contact with each other. Therefore, in this configuration, it is possible to control the drop position in the grinding water. Therefore, it is possible to prevent the grinding water from flowing to the outer peripheral side and reaching the side portion of the grinding wheel 40.

Further, in the present embodiment, the wheel mount 34 includes a grinding water receiving path 52, a cylinder 71, a piston 81 and a spring 91 in the cylinder 71, a first injection port 53, and a second injection port 55, respectively. A plurality (4) of the injection means are arranged with the center of the wheel mount 34 as the center and separated by an equal angle (90 degrees) along the center. Therefore, the grinding water can be evenly injected onto the surface to be ground 1a of the wafer 1 by the plurality of injection ports 53 and 55. This makes it possible to better cool the grinding wheel 40 and remove grinding debris.

In the present embodiment, when the rotation speed of the wheel mount 34 is the first rotation speed which is relatively slow, the position of the piston 81 does not change substantially and the first sliding valve 83 is the first feed. While remaining positioned at the outlet 75, when the rotational speed is a relatively high second rotational speed, the piston 81 moves outward against the urging force of the spring 91 and the second sliding. The urging force of the spring 91 is set so that the valve 85 is positioned at the second delivery port 77. In this regard, the wheel mount 34 may be configured to adjust the urging force of the spring 91.
In the modification shown in FIG. 11, the wheel mount 34 further includes an adjusting screw 95 for adjusting the urging force of the spring 91, an adjusting hole 101, and a connecting portion 103.

That is, in this modification, the adjusting hole 101 and the connecting portion 103 are provided on the radial outer side of the cylinder 71. The adjusting hole 101 extends on the extension line of the cylinder 71 until it penetrates the wheel mount 34. The connecting portion 103 is a relatively short cylinder provided between the cylinder 71 and the adjusting hole 101, and connects the cylinder 71 and the adjusting hole 101. The inner diameter of the connecting portion 103 may be, for example, substantially the same as the inner diameter of the cylinder 71.

In this modification, one end of the spring 91 is connected to the first sliding valve 83, and the other end of the spring 91 is connected to the adjusting screw 95. The adjusting screw 95 has an outer diameter substantially the same as the inner diameter of the connecting portion 103, and is arranged in the connecting portion 103. In this modification, a female screw is formed on the inner surface of the connecting portion 103, while a male screw screwable to the female screw of the connecting portion 103 is formed on the outer surface of the adjusting screw 95. Further, a minus groove M for a driver is formed at an end portion of the adjusting screw 95 on the outer side in the radial direction of the wheel mount 34. The minus groove M is exposed to the outside through the adjusting hole 101. Therefore, the adjusting screw 95 can be moved in the connecting portion 103 by engaging the screwdriver with the minus groove M and rotating the screwdriver.
Further, the adjusting hole 101 is formed with an inner diameter larger than the outer diameter of the adjusting screw 95 in order to allow the adjusting screw 95 to enter the connecting portion 103.
The adjusting screw 95, the adjusting hole 101, and the connecting portion 103 correspond to an example of the adjusting portion.

In this modification, the strength of the urging force of the spring 91 can be adjusted by the adjusting screw 95. That is, the urging force of the spring 91 can be increased by arranging the adjusting screw 95 relatively inside the connecting portion 103 and contracting the spring 91. On the other hand, by arranging the adjusting screw 95 relatively outside the connecting portion 103 and extending the spring 91, the urging force of the spring 91 can be weakened.

As described above, the second rotation speed of the wheel mount 34 is such that the first delivery port 75 is opened and the second delivery port 77 is closed by the second sliding valve 85. Is. The second rotational speed is determined by the centrifugal force applied to the piston 81 at this speed and the urging force of the spring 91. Therefore, in this modification, for example, the user can adjust the second rotational speed by adjusting the urging force of the spring 91.

1: Wafer, 1a: Surface to be ground,
2: Grinding device, 4: Base,
12: Chuck table, 13: Holding surface,
26: Grinding means, 28: Support structure, 30: Spindle housing,
32: Spindle, 33: Grinding water supply path,
34: Wheel mount, 34a: Spindle mounting surface, 34b: Wheel mounting surface,
36: Grinding wheel, 38: Wheel base, 40: Grinding wheel,
46: Grinding water supply source, 42: Supply pipe,
35: Mount flow path, 51: Connection port, 52: Grinding water receiving path,
53: 1st injection port, 55: 2nd injection port,
57: 1st connection path, 59: 2nd connection path,
65: 1st annular groove, 67: 2nd annular groove,
71: Cylinder, 73: Inlet, 75: Outlet,
75: 1st outlet, 77: 2nd outlet,
81: Piston, 83: First sliding valve, 85: Second sliding valve, 87: Connecting bar,
91: Spring, 95: Adjustment screw, 101: Adjustment hole, 103: Connection part, M: Minus groove

Claims (3)

A grinding device including a chuck table for holding a workpiece and a grinding means for rotatably supporting a grinding wheel having a grinding wheel arranged in an annular shape for grinding the workpiece held on the chuck table. There,
The grinding means includes a wheel mount that supports the grinding wheel, a rotating shaft connected to the center of the wheel mount, and a motor that rotates the rotating shaft.
Inside the rotating shaft, a grinding water supply path that reaches the wheel mount and supplies grinding water is formed.
The wheel mount has a first injection port that communicates with the grinding water supply path and is arranged on the circumference of a first circle having a first radius centered on the rotation axis, and the rotation axis. A second injection port provided with a second injection port arranged on the circumference of a second circle having a second radius larger than the first radius around the center of the injection means is arranged.
The injection means is
A receiving port that receives the grinding water in communication with the grinding water supply path, a first outlet that sends out the grinding water through the first injection port, and a second that sends out the grinding water through the second injection port. The cylinder in which the 2 outlets are formed and
The first sliding valve having the same outer diameter as the inner diameter of the cylinder and selectively closing the first outlet, and the second sliding valve having the same outer diameter as the inner diameter of the cylinder. A second sliding valve that selectively closes the delivery port, a piston having the first sliding valve and the second sliding valve at both ends and having a connecting bar smaller than the inner diameter of the cylinder.
It has a spring, which is disposed in the cylinder and urges the piston toward the center of the wheel mount to position the first sliding valve at the first outlet.
When the rotation speed of the wheel mount is a relatively slow first rotation speed, the first inlet / outlet is blocked by the first sliding valve, and the grinding water received at the inlet / outlet is the said. Guided to the second injection port through the connecting bar and the second outlet,
When the rotation speed of the wheel mount is a relatively high second rotation speed, the piston moves to the outer peripheral side of the wheel mount against the urging force of the spring, and the second outlet is the second. A grinding device in which the grinding water blocked by the sliding valve 2 and received at the inlet / outlet is guided to the first injection port through the connecting bar and the first inlet / outlet. The grinding apparatus according to claim 1, wherein a plurality of the injection means are arranged at an equal angle about the center of the wheel mount. Further, an adjusting unit for adjusting the urging force of the spring is provided.
The grinding apparatus according to claim 1.

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