JP2021003740A - Work-piece grinding method and grinding device - Google Patents

Abstract

To prevent an outer peripheral portion of a wafer suction-held on a holding surface of a chuck table from floating from the holding surface, when grinding the wafer by use of a grinding device.SOLUTION: A grinding method for a work-piece W, by which the work-piece W suction-held on a holding surface 300a of holding means 3 is ground by a grinding wheel 741, comprises: a holding process in which the work-piece W is held on the holding surface 300a; and a grinding process in which water is supplied from an outer peripheral nozzle 40, which is located on an outer side with respect to the holding means 3, toward an outer peripheral edge Wd of the work-piece W held on the holding surface 300a, and in the state that a circumference of the outer peripheral edge Wd is always filled with water, an upper face Wb of the work-piece W is ground by the grinding wheel 741.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for grinding a workpiece such as a semiconductor wafer and an apparatus for grinding.

In a grinding device that grinds a workpiece such as a semiconductor wafer with a grinding wheel, grinding is performed while the wafer is sucked and held on the holding surface of the chuck table (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-030055

In the conventional grinding apparatus, the holding surface of the chuck table is set to an area slightly smaller than the area of the held surface of the wafer. That is, the diameter of the holding surface of the chuck table is set to be slightly smaller than the diameter of the wafer. Therefore, even if the wafer is sucked and held by the chuck table, the outer peripheral portion of the wafer is not sucked in a ring shape. When the wafer is ground and thinned, the outer peripheral portion of the wafer is not attracted and held, so that the outer peripheral portion of the wafer is lifted by the pressing force received from the rotating grinding wheel, and the outer peripheral edge of the wafer is chipped.

Further, for example, a resin layer may be formed on one surface of the wafer, and in this case, the outer peripheral portion of the wafer on the resin layer side is curved so as to warp. Therefore, when grinding the resin layer with the resin layer of the wafer facing upward on the chuck table, the outer peripheral portion of the wafer is not suction-held and is not in close contact with the holding surface. There is a problem that the outer peripheral portion is ground more than the central region by grinding and becomes thinner. Further, a gap is formed when the outer peripheral portion of the wafer is separated from the holding surface, and grinding debris enters the gap to pollute the holding surface, and each time the wafer is sequentially ground, the holding surface becomes dirty and the holding surface of the chuck table is increased. There is a problem that the area where the outer peripheral portion of the wafer cannot be attracted is widened.

Therefore, when grinding a workpiece such as a semiconductor wafer using a grinding device, the outer peripheral portion of the workpiece sucked and held by the holding surface of the chuck table is prevented from floating from the holding surface. There are challenges.

The present invention for solving the above problems is a method for grinding a work piece, which grinds a work piece attracted and held by a holding surface of a holding means with a grinding wheel, and causes the work piece to be held on the holding surface. In the holding step, water is supplied from the outer peripheral nozzle arranged outside the holding means toward the outer peripheral edge of the workpiece held on the holding surface, and the periphery of the outer peripheral edge is always filled with water. A method for grinding a work piece, which comprises a grinding step of grinding the upper surface of the work piece with the grinding wheel.

In the method for grinding a work piece according to the present invention, the holding surface has an area larger than the area of the work piece, and in the grinding step, the holding surface is annular outside the outer peripheral edge of the work piece. It is preferable to form a water film on the exposed surface exposed to the surface with water supplied from the outer peripheral nozzle.

Further, in the present invention for solving the above problems, a holding means including a rotating mechanism for rotating a chuck table for holding the work piece on the holding surface and a work piece held on the holding surface are ground with a grinding wheel. A grinding device including a grinding tool for supplying water from the outer periphery of the chuck table toward the outer periphery of the holding surface, and a subject held on the holding surface from the outer peripheral nozzle. This is a grinding device that supplies water to the outer peripheral edge of a work piece and grinds the work piece with the grinding wheel while rotating the chuck table.

In the grinding apparatus according to the present invention, it is preferable that the holding surface of the chuck table has an area larger than the area of the workpiece.

The grinding method according to the present invention for grinding a workpiece sucked and held on the holding surface of the holding means with a grinding wheel includes a holding step of holding the workpiece on the holding surface and an outer circumference arranged outside the holding means. A grinding process in which water is supplied from the nozzle to the outer peripheral edge of the workpiece held on the holding surface, and the upper surface of the workpiece is ground with a grinding wheel while the outer peripheral edge is always filled with water. By providing the water supplied from the outer peripheral nozzle, the contact portion between the holding surface and the outer peripheral edge of the workpiece is sealed to prevent vacuum leakage, and the outer peripheral portion including the outer peripheral edge of the workpiece is lifted. It is possible to grind the workpiece so that it does not occur.

In the method for grinding a work piece according to the present invention, the holding surface has an area larger than the area of the work piece, and in the grinding process, the holding surface is exposed in an annular shape outside the outer peripheral edge of the work piece. By forming a water film with water supplied from the outer peripheral nozzle, the entire surface of the work piece to be sucked can be sucked and held by the holding surface while preventing vacuum leakage of the exposed surface. It is possible to grind the workpiece so that the outer peripheral portion including the outer peripheral edge of the object does not rise.

Further, the grinding apparatus according to the present invention includes a holding means provided with a rotating mechanism for rotating a chuck table for holding the workpiece on the holding surface, and a grinding means for grinding the workpiece held on the holding surface with a grinding wheel. , Equipped with an outer peripheral nozzle that supplies water from the outer periphery of the chuck table toward the outer periphery of the holding surface, and supplies water from the outer peripheral nozzle to the outer peripheral edge of the workpiece held on the holding surface to rotate the chuck table. While grinding the work piece with a grinding wheel, the water supplied from the outer peripheral nozzle seals the contact area between the holding surface and the outer peripheral edge of the work piece to prevent vacuum leakage, while the work piece is being worked. It is possible to grind the workpiece so that the outer peripheral portion including the outer peripheral edge does not rise.

In the grinding apparatus according to the present invention, the holding surface of the chuck table has an area larger than the area of the workpiece, so that the holding surface protrudes from the workpiece by the water film formed by the water supplied from the outer peripheral nozzle. The entire surface of the work piece to be sucked can be sucked and held by the holding surface while preventing the occurrence of vacuum leak on the annular exposed surface of the work piece, and the outer peripheral portion including the outer peripheral edge of the work piece is lifted. It is possible to grind the work piece without removing it.

It is a perspective view which shows an example of a grinding apparatus. A water film is formed on the exposed surface whose holding surface is annularly exposed outside the outer peripheral edge of the workpiece with water supplied from the outer peripheral nozzle, and the workpiece is always filled with water around the outer peripheral edge of the workpiece. It is sectional drawing explaining the state which the upper surface of an object is ground with a grinding wheel.

The grinding device 1 according to the present invention shown in FIG. 1 is a device that grinds the workpiece W held on the holding means 3 by the grinding means 7, and is forward (−Y direction) on the device base 10 of the grinding device 1. The side) is the area where the workpiece W is attached to and detached from the holding means 3, and the rear side (+ Y direction side) on the apparatus base 10 is the workpiece held on the holding means 3 by the grinding means 7. This is the area where the object W is ground.
The grinding device according to the present invention is not limited to a single-axis grinding device such as the grinding device 1, but includes at least two axes, a rough grinding means and a finish grinding means, and a turntable. It may be a grinding device or the like capable of positioning the workpiece below each grinding means.

The workpiece W is, for example, a circular semiconductor wafer made of a silicon base material or the like, and the surface Wa of the workpiece W facing downward in FIG. 1 has a plurality of devices in a region partitioned in a grid pattern. It is formed and is protected by a protective tape T having a diameter substantially the same as that of the workpiece W. The back surface Wb of the workpiece W is the surface to be ground to be ground. The workpiece W may be made of gallium arsenide, sapphire, gallium nitride, ceramics, resin, silicon carbide or the like in addition to silicon.

The holding means 3 for holding the work piece W is provided with a chuck table 30 for sucking and holding the work piece W. The chuck table 30 has, for example, a suction portion 300 having a circular outer shape and being made of a porous member or the like and sucking a workpiece W, and a frame body 301 having a concave vertical cross section and supporting the suction portion 300. And. The suction portion 300 fitted in the recess of the frame body 301 communicates with the suction source 37 shown in FIG. 2, and the work piece W is sucked and held by the holding surface 300a of the suction portion 300.
In the present embodiment, for example, the holding surface 300a of the chuck table 30 has an area larger than the area of the surface Wa of the workpiece W.

As shown in FIG. 1, the chuck table 30 is surrounded by a cover 100 and can be rotated by a rotation mechanism 36 (see FIG. 2) arranged below the cover 100. Further, the holding means 3 can be reciprocated in the Y-axis direction by the cover 100 shown in FIG. 1 and the Y-axis moving means (not shown) arranged below the bellows cover 100a connected to the cover 100. The cover 100 can be reciprocated in the Y-axis direction together with the chuck table 30, and the bellows cover 100a expands and contracts as the chuck table 30 and the cover 100 move in the Y-axis direction.

For example, drainage grooves of a water case (not shown) are located on both sides of the movement path of the chuck table 30. The water case receives the machining waste liquid and the like flowing down from the chuck table 30 including the grinding dust discharged when the workpiece W is ground, and sends it to a waste liquid treatment mechanism (not shown).

The rotation mechanism 36 is, for example, a pulley mechanism as shown in FIG. 2, and includes a table spindle 360 connected to the lower surface of the chuck table 30 and extending perpendicularly to the chuck table 30. A driving pulley 362 is attached to the shaft of the motor 361 that is a drive source for rotating the table spindle 360, and an endless belt 364 is wound around the driving pulley 362. A driven pulley 363 is attached to the table spindle 360, and the endless belt 364 is also wound around the driven pulley 363. When the motor 361 shown in FIG. 2 rotationally drives the main pulley 362, the endless belt 364 rotates with the rotation of the main pulley 362, and the endless belt 364 rotates to cause the driven pulley 363 and the table spindle 360 to rotate. Rotate.

A suction flow path 370 communicating with the suction portion 300 is formed from the bottom surface of the recess of the frame body 301 to the lower surface of the frame body 301, and further from the lower surface to the table spindle 360. The suction flow path 370 communicates with a suction source 37 such as an ejector mechanism or a vacuum generator via a rotary joint 373 arranged so as to surround the table spindle 360 and a pipe 374. The rotary joint 373 transfers the suction force generated by the suction source 37 to the table spindle 360 side without omission.

For example, a first on-off valve 375 is arranged in the pipe 374. Further, a pressure gauge 376 is arranged in the pipe 374 to measure the negative pressure in the pipe 374 while the suction source 37 is operated and the chuck table 30 is sucking and holding the workpiece W. Therefore, it is possible to monitor whether or not a vacuum leak has occurred from the holding surface 300a of the chuck table 30.

For example, a branch pipe 45 communicates in the middle of the pipe 374, and the upstream side of the branch pipe 45 further branches into two, and is composed of a compressor or the like via a second on-off valve 462 and can supply compressed air. In addition to communicating with the air supply source 46, it communicates with a water supply source 47 composed of a pump or the like and capable of supplying cleaning water such as pure water via a third on-off valve 473.

For example, when it is desired to release the suction holding of the workpiece W by the chuck table 30 and carry out the workpiece W from the chuck table 30, the first on-off valve 375 and the third on-off valve 473 are closed. , The second on-off valve 462 is opened, and the air supply source 46 supplies compressed air to the branch pipe 45. The compressed air passes through the branch pipe 45, the pipe 374, and the suction flow path 370, and is ejected from the holding surface 300a of the chuck table 30. As a result, the vacuum suction force remaining between the holding surface 300a and the protective tape T attached to the surface Wa of the workpiece W is eliminated, and the workpiece W can be separated from the holding surface 300a. can do.

For example, when it is desired to remove the grinding debris stuck in the suction portion 300 of the chuck table 30 from the suction portion 300, the second on-off valve 462 or the third on-off valve 473 is opened with the first on-off valve 375 closed. Then, the air supply source 46 supplies compressed air to the branch pipe 45, or the water supply source 47 supplies pure water to the branch pipe 45. The compressed air or pure water, or the two fluids obtained by mixing the compressed air and pure water, pass through the branch pipe 45, the pipe 374, the suction flow path 370, and the suction portion 300, and are ejected from the holding surface 300a of the chuck table 30. As a result, the grinding debris and the like that have entered the suction portion 300 can be ejected from the holding surface 300a and removed.

A column 11 is erected behind the device base 10 shown in FIG. 1 (on the + Y direction side).
On the front surface of the column 11, a grinding feed means 5 for moving the grinding means 7 in the Z-axis direction orthogonal to the Y-axis direction and perpendicular to the holding surface 300a of the holding means 3 is arranged. The grinding feed means 5 includes a ball screw 50 having an axial center in the Z-axis direction, a pair of guide rails 51 arranged in parallel with the ball screw 50, and a motor 52 connected to the upper end of the ball screw 50 to rotate the ball screw 50. The elevating plate 53 is provided with an internal nut screwed into the ball screw 50 and the side portion is in sliding contact with the guide rail 51. When the motor 52 rotates the ball screw 50, the elevating plate 53 moves with the guide rail 51. Guided by the ball screw, it reciprocates in the Z-axis direction, and the grinding means 7 fixed to the elevating plate 53 is grounded and fed in the Z-axis direction.

The grinding means 7 has a spindle 70 whose axial direction is the Z-axis direction, a housing 71 that rotatably supports the spindle 70, a motor 72 that rotationally drives the spindle 70, and a circular plate shape connected to the tip of the spindle 70. The mount 73, a grinding wheel 74 mounted on the lower surface of the mount 73, and a holder 75 that supports the housing 71 and has its side surface fixed to the elevating plate 53 of the grinding feed means 5.

The grinding wheel 74 shown in FIG. 1 includes a wheel base 740 having an annular shape in a plan view, and a plurality of substantially rectangular parallelepiped grinding wheels 741 are arranged in an annular shape in a region on the outer peripheral side of the bottom surface of the wheel base 740. Has been done. The grinding wheel 741 is formed by fixing diamond abrasive grains or the like with a predetermined bonding agent.

The grinding apparatus 1 according to the present invention includes an outer peripheral nozzle 40 that supplies water from the outer periphery of the chuck table 30 toward the outer periphery of the holding surface 300a. The outer peripheral nozzles 40 are arranged at four corners on the cover 100 surrounding the chuck table 30, for example. The outer peripheral nozzle 40 is erected from the cover 100, for example, and has a substantially inverted L-shaped outer shape in a side view. The supply port 400 formed at the tip of the outer peripheral nozzle 40 and opening toward the chuck table 30 side is located at a position higher than the holding surface 300a of the chuck table 30, for example, and is ejected horizontally from the supply port 400, for example. The water can reach the outer peripheral region of the holding surface 300a in a parabolic manner.

The number of outer peripheral nozzles 40 arranged is not limited to four as shown in FIG. 1, and the shape thereof is not limited to the examples shown in FIGS. 1 and 2.
Further, the arrangement location is not limited to the cover 100. For example, the grinding device 1 may include a processing chamber (not shown) that houses a chuck table 30 that has moved below the grinding means 7 and a grinding wheel 74. The processing chamber includes a top plate, a bottom plate, and a side plate that connects the top plate and the bottom plate and surrounds the chuck table 30 and the grinding wheel 74, and the outer peripheral nozzle attaches the chuck table 30 to the top plate and the side plate. A plurality of them may be arranged so as to surround them.

One end of a pipe 41 communicates with each outer peripheral nozzle 40, and each pipe 41 communicates with, for example, one pipe and then the other end side communicates with the water supply source 47. For example, the fourth on-off valve 414 may be arranged in the pipe 41.

The operation of each part of the grinding device 1 and each step of the grinding method when the upper surface of the workpiece W is ground by using the grinding device 1 shown in FIG. 1 will be described below.

(1) Holding Step First, the workpiece W is placed on the holding surface 300a with the back surface Wb facing upward so that the center of the chuck table 30 and the center of the workpiece W substantially coincide with each other. .. Further, the first on-off valve 375 shown in FIG. 2 is opened to communicate the suction source 37 and the pipe 374, and in this state, the suction force generated by the operation of the suction source 37 is generated by the rotary joint 373 and the suction flow. It is transmitted to the holding surface 300a of the chuck table 30 through the passage 370 and the suction portion 300. Then, the chuck table 30 sucks and holds the workpiece W with the back surface Wb facing upward.

(2) Grinding Step In the present embodiment, the holding surface 300a of the chuck table 30 is set to an area larger than the area of the workpiece W. That is, the diameter of the holding surface 300a is set to be larger than that of the workpiece W. For example, as shown in FIG. 2, the holding surface 300a is annularly exposed outside the outer peripheral edge Wd of the workpiece W. The exposed surface 300b is formed. For example, the width of the annular exposed surface 300b (distance from the outer peripheral edge Wd of the workpiece W to the inner circumference of the frame 301) is about 2 mm.

In this embodiment, in order to prevent a vacuum leak from occurring on the annular exposed surface 300b of the chuck table 30, the chuck table 30 is held on the holding surface 300a from the outer peripheral nozzle 40 arranged radially outside the holding means 3. Water is supplied toward the outer peripheral edge Wd of the workpiece W so that the periphery of the outer peripheral edge Wd is filled with water, and for example, the holding surface 300a is annularly formed outside the outer peripheral edge Wd of the workpiece W. A water film is formed on the exposed exposed surface 300b with water supplied from the outer peripheral nozzle 40.

As shown in FIG. 2, the water supply source 47 supplies water (for example, pure water) to the pipe 41 in a state where the third on-off valve 473 is closed and the fourth on-off valve 414 is open. Water passes through the pipe 41 and is ejected from the supply port 400 of each outer peripheral nozzle 40. The water ejected from the supply port 400 of each outer peripheral nozzle 40 reaches the outer peripheral edge Wd of the workpiece W, and the periphery of the outer peripheral edge Wd is filled with water to form a water film M (water seal M).
Further, the water ejected from the supply port 400 of each outer peripheral nozzle 40 reaches the exposed surface 300b where the holding surface 300a is annularly exposed outside the outer peripheral edge Wd of the workpiece W, and the water is exposed by surface tension. A water seal M is formed by forming a film covering the surface 300b. The water seal M prevents a vacuum leak from occurring on the exposed surface 300b.

Next, the chuck table 30 holding the workpiece W moves to the bottom of the grinding means 7 shown in FIGS. 1 and 2 in the + Y direction, and the rotation center of the grinding wheel 74 of the grinding means 7 rotates the workpiece W. The chuck table 30 is positioned so that the rotation locus of the grinding wheel 741 passes through the rotation center of the workpiece W, which is displaced horizontally by a predetermined distance from the center.

As described above, the outer peripheral edge Wd of the workpiece W is filled with water with the water supplied from the outer peripheral nozzle 40, and the water seal M is formed on the exposed surface 300b with the water supplied from the outer peripheral nozzle 40. Make it in the formed state. For example, while the chuck table 30 that sucks and holds the workpiece W moves from the attachment / detachment region on the apparatus base 10 shown in FIG. 1 to a predetermined position below the grinding means 7 in the grinding region, the outer peripheral nozzle 40 The outer peripheral edge Wd of the workpiece W is filled with water with the water supplied from the outer peripheral nozzle 40, and the water seal M is formed on the exposed surface 300b with the water supplied from the outer peripheral nozzle 40.

As shown in FIG. 2, the chuck table 30 that sucks and holds the workpiece W moves to the grinding region, the grinding means 7 is fed by the grinding feed means 5 in the −Z direction, and rotates as the spindle 70 rotates. Grinding is performed when the grinding wheel 741 is in contact with the back surface Wb of the workpiece W. During grinding, as the chuck table 30 rotates about the Z axis by the rotation mechanism 36, the workpiece W held on the holding surface 300a also rotates, so that the grinding wheel 741 is the workpiece W. Grind the entire surface of the back surface Wb, which is the upper surface.

While the workpiece W is being ground as described above, the outer peripheral nozzle 40 arranged outside the holding means 3 toward the outer peripheral edge Wd of the workpiece W held on the holding surface 300a. Water is supplied, and the outer peripheral edge Wd is always maintained to be filled with water. On the surface Wa side of the workpiece W having an area smaller than the holding surface 300a, the entire surface Wa is suction-held by the holding surface 300a, and the suction force acting on the outer peripheral edge Wd from the holding surface 300a is applied. Since the water seal M suppresses the lowering, it is possible to prevent the outer peripheral edge Wd of the workpiece W from being lifted by the pressing force received from the rotating grinding wheel 741. Therefore, the vacuum leak does not occur on the holding surface 300a, and the workpiece W can be ground so that the outer peripheral edge Wd of the workpiece W does not rise.
The outer peripheral nozzle 40 is arranged on the cover 39 so that the grinding wheel 741 does not come into contact with the outer peripheral nozzle 40.
Further, the water supplied from the outer peripheral nozzle 40 covers the exposed surface 300b, and the water receives centrifugal force due to the rotation of the chuck table 30. The water subjected to the centrifugal force flows out of the chuck table 30 together with the grinding dust obtained by grinding the workpiece W by the grinding wheel 741, so that the grinding dust is not sucked into the exposed surface 300b.

For example, as shown in FIG. 2, the supply ports 400 of at least one outer peripheral nozzle 40 among the four outer peripheral nozzles 40 shown in FIG. 1 are arranged in an annular shape on the inner surface of the wheel base 740 of the grinding wheel 74. It is in a state of substantially facing the inner surface of the grinding wheel 741. Therefore, by increasing the amount of water supplied from the water supply source 47, etc., a part of the water jetted from the supply port 400 of the one outer peripheral nozzle 40 is not used as water that always fills the periphery of the outer peripheral edge Wd. The contact portion between the grinding wheel 741 and the workpiece W may be acted as water for cooling / cleaning from the inner surface side of the rotating grinding wheel 74. The water that cools and cleans the contact portion flows down from the chuck table 30 together with the grinding dust and flows into a water case (not shown).

The chuck table 30 is rotating during the grinding process, and when centrifugal force is applied to the water injected from the outer peripheral nozzle 40 and reaching the periphery of the outer peripheral edge Wd of the workpiece W, the water is generated around the outer peripheral edge Wd. However, since water is always supplied to the outer peripheral edge Wd from each outer peripheral nozzle 40, a state in which the periphery of the outer peripheral edge Wd of the workpiece W is always filled with water is maintained.

Further, in the present embodiment, the holding surface 300a of the chuck table 30 has an area larger than the area of the workpiece W, and the entire surface Wa side of the workpiece W to be held can be suction-held. .. Further, during the grinding process, a water film M (water seal M) is formed with water supplied from the outer peripheral nozzle 40 on the exposed surface 300b whose holding surface 300a is annularly exposed outside the outer peripheral edge Wd of the workpiece W. Therefore, it is possible to grind the workpiece W so that the vacuum leak of the exposed surface 300b does not occur and the outer peripheral edge Wd of the workpiece W does not rise.

While the thickness of the workpiece W is being measured, the workpiece W is ground to a desired thickness, and then the grinding feed means 5 shown in FIG. 1 raises the grinding means 7 and separates it from the workpiece W. The grinding process of the workpiece W is completed.

In the grinding process, water is drawn into the suction flow path 370 from the exposed surface 300b of the chuck table 30 shown in FIG. If the exposed surface 300b is too wide, the amount of water drawn into the suction flow path 370 increases and the suction force of the suction source 37 decreases. Therefore, it is preferable that the exposed surface 300b is narrow.

As described above, the grinding method according to the present invention for grinding the workpiece W sucked and held on the holding surface 300a of the holding means 3 with the grinding wheel 741 includes a holding step of holding the workpiece W on the holding surface 300a. , A state in which water is supplied from the outer peripheral nozzle 40 arranged outside the holding means 3 toward the outer peripheral edge Wd of the workpiece W held on the holding surface 300a, and the periphery of the outer peripheral edge Wd is always filled with water. By providing a grinding step of grinding the upper surface (back surface Wb in the present embodiment) of the workpiece W with a grinding wheel 741, the holding surface 300a and the outside of the workpiece W are provided with water supplied from the outer peripheral nozzle 40. It is possible to grind the workpiece W so that the circumference of the contact portion with the peripheral edge Wd is sealed so that vacuum leak does not occur, and the outer peripheral portion including the outer peripheral edge Wd of the workpiece W does not rise. It becomes.

In the method for grinding the workpiece W according to the present invention, the holding surface 300a has an area larger than the area of the workpiece W, and in the grinding process, the holding surface 300a is outside the outer peripheral edge Wd of the workpiece W. By forming a water film M (water seal M) with water supplied from the outer peripheral nozzle 40 on the exposed surface 300b exposed in an annular shape, suction of the workpiece W is prevented while vacuum leakage of the exposed surface 300b does not occur. The entire surface Wa, which is the lower surface to be formed, can be suction-held by the holding surface 300a, and the workpiece W can be ground so that the outer peripheral portion including the outer peripheral edge Wd of the workpiece W does not rise. It becomes.

Further, the grinding device 1 according to the present invention has a holding means 3 provided with a rotating mechanism 36 for rotating a chuck table 30 that holds the workpiece W on the holding surface 300a, and a workpiece W held on the holding surface 300a. A grinding means 7 for grinding with a grinding wheel 741 and an outer peripheral nozzle 40 for supplying water from the outer periphery of the chuck table 30 toward the outer periphery of the holding surface 300a, and a cover held from the outer peripheral nozzle 40 to the holding surface 300a. By supplying water to the outer peripheral edge Wd of the workpiece W and grinding the workpiece W with the grinding wheel 741 while rotating the chuck table 30, the holding surface 300a and the workpiece W are separated by the water supplied from the outer peripheral nozzle 40. It is possible to grind the workpiece W so that the circumference of the contact portion with the outer peripheral edge Wd is sealed so that vacuum leak does not occur, and the outer peripheral portion including the outer peripheral edge Wd of the workpiece W does not rise. It will be possible.

In the grinding apparatus 1 according to the present invention, the holding surface 300a of the chuck table 30 has an area larger than the area of the workpiece W, and is covered by the water film M formed by the water supplied from the outer peripheral nozzle 40. The entire surface Wa of the workpiece W to be sucked can be sucked and held by the holding surface 300a while preventing the occurrence of vacuum leak of the annular exposed surface 300b of the holding surface 300a protruding from the workpiece W. It is possible to grind the workpiece W so that the outer peripheral portion including the outer peripheral edge Wd of the object W does not rise.
The holding surface 300a of the chuck table 30 has an area larger than the area of the workpiece W, and water is supplied from the outer peripheral nozzle 40 to the annular exposed surface 300b to form a water film M to form the water film M. The water that has been continuously supplied for this purpose receives centrifugal force as the chuck table 30 rotates and flows outward, so that the problem that the grinding debris is sucked into the exposed surface 300b does not occur.

Needless to say, the grinding method according to the present invention is not limited to the above embodiment, and may be implemented in various different forms within the scope of the technical idea. Further, the shape and the like of each configuration of the grinding apparatus 1 shown in the attached drawings are not limited to this, and can be appropriately changed within the range in which the effects of the present invention can be exhibited.

The surface Wa of the workpiece W may be molded with a predetermined resin to form a resin layer having a uniform thickness. In this case, the workpiece W is curved so that the outer peripheral portion on the resin layer side is warped due to the heat effect (shrinkage of the resin layer, etc.) during the formation of the resin layer. Then, the workpiece W may be placed with the surface Wa on which the resin layer is formed on the holding surface 300a of the holding means 3 facing upward, and the resin layer may serve as the surface to be ground.

The holding surface 300a of the chuck table 30 may have an area smaller than the area of the workpiece W. In this case, even if the outer peripheral edge Wd of the workpiece W is warped upward, water is supplied from the outer peripheral nozzle 40, so that the upper surface of the workpiece W is always filled with water around the outer peripheral edge Wd. By grinding the resin layer to be formed with a grinding wheel 741, there is no gap between the outer peripheral edge Wd of the workpiece W and the upper surface of the frame 301 due to the water seal formed, and no vacuum leak is generated. Grinding can be carried out without adhering grinding debris to the upper surface of the frame body 301 which is an exposed surface.

W: Work piece Wa: Surface of work work Wb: Back side of work work T: Protective tape 1: Grinding device 10: Device base 100: Cover 100a: Bellows cover 11: Column 3: Holding means
30: Chuck table 300: Suction part 300a: Holding surface 301: Frame body 36: Rotating mechanism 360: Table spindle 361: Motor 370: Suction flow path 373: Rotary joint 374: Piping 375: First on-off valve 376: Pressure gauge 37 : Suction source 45: Branch pipe 462: Second on-off valve 46: Air supply source 473: Third on-off valve 47: Water supply source 5: Grinding feed means 7: Grinding means 741: Grinding grindstone 40: Outer peripheral nozzle 400: Outer peripheral nozzle Supply port 41: Piping 414: Fourth on-off valve

Claims (4)

A method for grinding a workpiece that is suction-held on the holding surface of the holding means with a grinding wheel.
A holding step of holding the work piece on the holding surface and
Water is supplied from the outer peripheral nozzle arranged outside the holding means toward the outer peripheral edge of the workpiece held on the holding surface, and the workpiece is always filled with water around the outer peripheral edge. A method for grinding a workpiece, comprising a grinding step of grinding the upper surface of the work piece with the grinding wheel. The holding surface has an area larger than the area of the work piece and is
The method for grinding a workpiece according to claim 1, wherein in the grinding step, a water film is formed on an exposed surface whose holding surface is annularly exposed outside the outer peripheral edge of the workpiece with water supplied from the outer peripheral nozzle. .. A grinding device including a holding means provided with a rotating mechanism for rotating a chuck table for holding a workpiece on the holding surface, and a grinding means for grinding the workpiece held on the holding surface with a grinding wheel.
An outer peripheral nozzle for supplying water from the outer periphery of the chuck table toward the outer periphery of the holding surface is provided.
A grinding device that supplies water from the outer peripheral nozzle to the outer peripheral edge of the workpiece held on the holding surface and grinds the workpiece with the grinding wheel while rotating the chuck table. The grinding apparatus according to claim 3, wherein the holding surface has an area larger than the area of the workpiece.

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