JP2004356480A - Grinding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding device for grinding a workpiece by a grinding wheel whose flexible members are mixed with abrasives in order to make its thickness uniform. <P>SOLUTION: This grinding device is provided with a chuck table mechanism having a chuck table 52 equipped with a holding face 522a for holding a workpiece and a driving means for driving the rotation of the chuck table, a grinding unit having a grinding wheel whose flexible members are mixed with abrasives for grinding the workpiece held on the holding face of the chuck table and a driving means for driving the rotation of the grinding wheel and a grinding unit feeding mechanism for moving back and forth the grinding unit perpendicular to the holding face of the chuck table. The holding face of the chuck table is formed as a spherical surface-shaped recess curved surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polishing apparatus for polishing a workpiece such as a semiconductor wafer held on a chuck table.
[0002]
[Prior art]
In a semiconductor device manufacturing process, a large number of rectangular regions are partitioned by cutting lines called streets arranged in a grid on the surface of a substantially disk-shaped semiconductor wafer, and a semiconductor circuit is formed in each of the rectangular regions. By separating the semiconductor wafer on which a large number of semiconductor circuits are formed along the streets, individual semiconductor chips are formed. In order to reduce the size and weight of the semiconductor chip, the semiconductor wafer is usually ground to a predetermined thickness by cutting the semiconductor wafer along streets to separate individual rectangular regions. Has formed. Grinding of the back surface of a semiconductor wafer is usually performed by pressing a grinding wheel formed by fixing diamond abrasive grains with an appropriate bond such as a resin bond against the back surface of the semiconductor wafer while rotating at a high speed. When the back surface of the semiconductor wafer is ground by such a grinding method, a so-called processing strain is generated on the back surface of the semiconductor wafer, thereby considerably reducing the bending strength of the individually divided semiconductor chips. As a measure for removing processing strain generated on the back surface of the ground semiconductor wafer, a wet etching method of chemically etching the back surface of the ground semiconductor wafer using an etching solution containing nitric acid and hydrofluoric acid, A dry etching method using an etching gas is used.
[0003]
However, the above-described wet etching method, dry etching method, and polishing method have low productivity, and the waste liquid causes environmental pollution. In order to solve such problems, a polishing tool that uses a felt whetstone in which abrasive grains are dispersed in felt and fixed with an appropriate bonding agent is proposed as a polishing tool that removes distortion by polishing the back surface of the polished semiconductor wafer. Have been. (For example, refer to Patent Document 1.)
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-283243
[Problems to be solved by the invention]
Thus, in the polishing tool disclosed in the above publication, the polishing wheel is formed of a flexible felt. Therefore, when the surface to be polished of the semiconductor wafer is uniformly pressed by the polishing wheel, the central region of the semiconductor wafer is polished more. Therefore, there is a problem that the surface to be polished is polished to a spherical concave curved surface. Further, since the central region of the semiconductor wafer is polished a lot, heat is accumulated in the central portion, and the heat causes the central portion of the protective tape adhered to the surface of the semiconductor wafer (the surface on which the circuit is formed). There is also a problem of melting.
[0006]
The present invention has been made in view of the above facts, and its main technical problem is that even if a workpiece is polished by a polishing grindstone in which abrasive grains are mixed into a flexible member, it can be polished to a uniform thickness. An object of the present invention is to provide a polishing apparatus.
[0007]
[Means for Solving the Problems]
In order to solve the main technical problem, according to the present invention, a chuck table having a holding surface for holding a workpiece, a chuck table mechanism including a driving unit for rotating the chuck table, and a chuck table A polishing unit provided with a polishing grindstone in which abrasive grains are mixed in a flexible member for polishing a workpiece held on the holding surface, and a driving unit for rotating and driving the polishing grindstone; and A polishing unit having a polishing unit feed mechanism for reciprocating in a direction perpendicular to the holding surface of the chuck table,
The holding surface of the chuck table is formed as a spherical concave curved surface,
A polishing apparatus is provided.
[0008]
The radius of curvature of the spherical concave surface is desirably set to 100 to 1000 m. Further, the above-mentioned polishing grindstone is made of a felt grindstone in which abrasive grains are dispersed in felt and fixed with an appropriate bonding agent.
[0009]
According to another aspect of the present invention, there is provided a chuck table having a holding surface for holding a workpiece, a chuck table mechanism including a driving unit for rotating the chuck table, and the chuck. A polishing unit including a polishing grindstone in which abrasive grains are mixed in a flexible member for polishing a workpiece held on the holding surface of a table, and a driving unit for rotating and driving the polishing grindstone; and the polishing unit. A polishing unit feed mechanism that moves the chuck table in a direction perpendicular to the holding surface,
The rotation axis of the chuck table and the rotation axis of the grinding wheel are configured with a predetermined intersection angle,
A polishing apparatus is provided.
[0010]
The intersection angle between the rotation axis of the chuck table and the rotation axis of the polishing grindstone is desirably set to 0.0001 to 0.002 radians. The polishing grindstone is made of a felt grindstone in which abrasive grains are dispersed in felt and fixed with an appropriate bonding agent.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a polishing apparatus configured according to the present invention will be described in detail with reference to the accompanying drawings.
[0012]
FIG. 1 is a perspective view of a polishing apparatus constituted according to the present invention.
The polishing apparatus comprises an apparatus housing, generally designated by the numeral 2. The device housing 2 has a rectangular main body 21 that is elongated and an upright wall 22 that is provided at a rear end (upper right end in FIG. 1) of the main part 21 and extends substantially vertically upward. I have. A pair of guide rails 221 and 221 extending in the vertical direction are provided on the front surface of the upright wall 22. The polishing unit 3 is mounted on the pair of guide rails 221 and 221 so as to be vertically movable.
[0013]
The polishing unit 3 includes a moving base 31 and a spindle unit 32 mounted on the moving base 31. The movable base 31 is provided with a pair of legs 311, 311 vertically extending on both sides of the rear surface, and slidably engages the pair of guide rails 221, 221 with the pair of legs 311, 311. Guide grooves 312 and 312 are formed. As described above, a support portion 313 protruding forward is provided on the front surface of the movable base 31 slidably mounted on the pair of guide rails 221 and 221 provided on the upright wall 22. The spindle unit 32 is attached to the support portion 313.
[0014]
The spindle unit 32 includes a spindle housing 321 mounted on the support portion 313, a rotary spindle 322 rotatably disposed on the spindle housing 321, and a servo motor as a driving unit for driving the rotary spindle 322 to rotate. 323. The lower end of the rotary spindle 322 projects downward beyond the lower end of the spindle housing 321, and a disk-shaped tool mounting member 324 is provided at the lower end. A plurality of bolt insertion holes (not shown) are formed in the tool mounting member 324 at intervals in the circumferential direction. A polishing tool 325 is mounted on the lower surface of the tool mounting member 324. The polishing tool 325 includes a disk-shaped support member 326 and a disk-shaped polishing wheel 327 as shown in FIGS. The support member 326 has a plurality of blind screw holes 326a extending downward from the upper surface thereof at intervals in the circumferential direction. The lower surface of the support member 326 forms a circular support surface, and the polishing grindstone 327 is joined to the circular support surface of the support member 326 by an appropriate adhesive such as an epoxy resin adhesive. The polishing grindstone 327 is one in which abrasive grains are dispersed in a flexible member such as felt and fixed with an appropriate bonding agent. In the illustrated embodiment, a felt grindstone using felt as the flexible member is used. The configuration of the polishing grindstone 327 itself made of the felt grindstone is described in detail in the above-mentioned Japanese Patent Application Laid-Open No. 2002-283243, so it is left to such description, and the description is omitted in this specification. The polishing tool 325 is positioned on the lower surface of the tool mounting member 324 fixed to the lower end of the rotary spindle 322, and a blind screw formed on the support member 326 of the polishing tool 325 through a through hole formed in the tool mounting member 324. By screwing the fastening bolt 328 into the hole 326a, the polishing tool 325 is mounted on the tool mounting member 324.
[0015]
Returning to FIG. 1, the polishing apparatus according to the illustrated embodiment moves the polishing unit 3 vertically along the pair of guide rails 221 and 221 (perpendicular to a holding surface of a chuck table described later). ) Is provided with a polishing unit feed mechanism 4 for moving the polishing unit in the direction (1). The polishing unit feed mechanism 4 includes a male screw rod 41 disposed on the front side of the upright wall 22 and extending substantially vertically. The male screw rod 41 is rotatably supported at its upper end and lower end by bearing members 42 and 43 attached to the upright wall 22. The upper bearing member 42 is provided with a pulse motor 44 as a drive source for rotationally driving the male screw rod 41, and the output shaft of the pulse motor 44 is operatively connected to the male screw rod 41. A connecting portion (not shown) projecting rearward from the center portion in the width direction is also formed on the rear surface of the movable base 31, and a penetrating female screw hole extending in the vertical direction is formed in this connecting portion. The male screw rod 41 is screwed into the female screw hole. Therefore, when the pulse motor 44 rotates forward, the moving base 31, ie, the polishing unit 3, is lowered or moved forward, and when the pulse motor 44 rotates reversely, the moving base 31, ie, the polishing unit 3 is raised, ie, moved backward.
[0016]
1 and 4, a substantially rectangular working section 211 is formed on the rear half of the main section 21 of the housing 2, and the chuck table mechanism 5 is provided on the working section 211. It is arranged. The chuck table mechanism 5 includes a support base 51 and a disk-shaped chuck table 52 rotatably disposed on the support base 51. The support base 51 is slidable on a pair of guide rails 23, 23 extending in the front-rear direction (the direction perpendicular to the front surface of the upright wall 22) in the directions indicated by arrows 23a and 23b. 1 and a grinding wheel of a grinding tool 325 constituting the spindle unit 32 by a chuck table moving mechanism 56 described later and a workpiece loading / unloading area 24 (a position shown by a solid line in FIG. 1) shown in FIG. 327 is moved between the polishing surface (lower surface) 327 and the opposing polishing region 25 (the position shown by a two-dot chain line in FIG. 4). The chuck table 52 is rotatably supported by the support base 51. The chuck table 52 is rotated by a servomotor 53 serving as a rotation driving means connected to a rotation shaft (not shown) mounted on the lower end thereof. The illustrated chuck table mechanism 5 includes a cover member 54 (see FIG. 1) having a hole through which the chuck table 52 is inserted and covering the support base 51 and the like. It is configured to be movable.
[0017]
Here, the chuck table 52 will be described with reference to FIG.
The chuck table 52 in the illustrated embodiment includes a table main body 521 and a suction chuck 522 mounted on the upper surface of the table main body 521. An annular frame 523 made of fine ceramics is fitted around the outer periphery of the suction chuck 522, and the frame 523 is mounted on the table body 521 by a plurality of mounting bolts 524. The table main body 521 is provided with a suction groove 521a opened on the upper surface and a suction passage 521b communicating with the suction groove 521a, and the suction passage 521b is connected to suction means (not shown). The suction chuck 522 is made of an appropriate porous material such as a porous ceramic, and a holding surface 522a for holding a workpiece, which is an upper surface thereof, is formed in a spherical concave curved surface. The radius of curvature (R) of the spherical concave surface forming the holding surface 522a is set to 100 to 1000 m. When the radius of curvature is set to 500 m, when the diameter of the suction chuck 522 is 200 mm, a gap (G) of about 20 μm is formed between the center and the outer periphery of the suction chuck 522. The suction chuck 522 made of porous ceramics may be made of alumina. However, if it is made of silicon carbide having good thermal conductivity, the semiconductor wafer can be effectively cooled during polishing.
[0018]
4, the polishing apparatus according to the illustrated embodiment includes a chuck table moving mechanism 56 that moves the chuck table mechanism 5 along the pair of guide rails 23 in the directions indicated by arrows 23a and 23b. I have it. The chuck table moving mechanism 56 includes a male screw rod 561 disposed between the pair of guide rails 23 and extending in parallel with the guide rails 23, and a servo motor 562 for driving the male screw rod 561 to rotate. The male screw rod 561 is screwed into a screw hole 511 provided in the support base 51, and its tip is rotatably supported by a bearing member 563 attached by connecting the pair of guide rails 23. ing. The servomotor 562 has a drive shaft that is drivingly connected to the base end of the male screw rod 561. Therefore, when the servo motor 562 rotates forward, the support base 53, ie, the chuck table mechanism 5 moves in the direction shown by the arrow 23a, and when the servo motor 562 rotates in the reverse direction, the support base 53, ie, the chuck table mechanism 5 moves in the direction shown by the arrow 23b. Moved. The chuck table mechanism 5 that is moved in the directions indicated by the arrows 23a and 23b is selectively positioned in a workpiece loading / unloading area indicated by a solid line and a polishing area indicated by a two-dot chain line in FIG.
[0019]
Returning to FIG. 1, the description will be continued. On both sides of the support base 51 constituting the chuck table mechanism 5 in the moving direction, as shown in FIG. Bellows means 61 and 62 for covering the rails 23, the male screw rod 561, the servomotor 562, and the like are provided. Bellows means 61 and 62 can be formed from any suitable material such as campus cloth. The front end of the bellows means 61 is fixed to the front wall of the immersion part 211, and the rear end is fixed to the front end face of the cover member 54 of the chuck table mechanism 5. The front end of the bellows means 62 is fixed to the rear end surface of the cover member 54 of the chuck table mechanism 5, and the rear end is fixed to the front surface of the upright wall 22 of the apparatus housing 2. When the chuck table mechanism 5 is moved in the direction shown by the arrow 23a, the bellows means 61 is extended and the bellows means 62 is contracted. When the chuck table mechanism 5 is moved in the direction shown by the arrow 23b, the bellows means is moved. 61 is contracted, and the bellows means 62 is extended.
[0020]
On the first half of the main part 21 of the apparatus housing 2, a first cassette 11, a second cassette 12, a work piece temporary mounting means 13, a cleaning means 14, and a work transfer means 15 are provided. , A workpiece carrying-in means 16 and a workpiece carrying-out means 17 are provided. The first cassette 11 stores a workpiece before polishing, and is placed in a cassette loading area in the main part 21 of the apparatus housing 2. The second cassette 12 is placed in a cassette unloading area in the main portion 21 of the apparatus housing 2 and stores a workpiece after polishing. The workpiece temporary mounting means 13 is disposed between the first cassette 11 and the workpiece loading / unloading area 24, and temporarily places the workpiece before polishing. The cleaning means 14 is disposed between the workpiece loading / unloading area 24 and the second cassette 12, and cleans the workpiece after polishing. The workpiece transfer means 15 is disposed between the first cassette 11 and the second cassette 12, and unloads the workpiece stored in the first cassette 11 to the temporary workpiece placement means 13. At the same time, the workpiece cleaned by the cleaning means 14 is transported to the second cassette 12. The workpiece loading means 16 is disposed between the workpiece temporary mounting means 13 and the workpiece loading / unloading area 24, and is placed on the workpiece temporary loading means 13 before polishing. The workpiece is transported onto the chuck table 52 of the chuck table mechanism 5 positioned in the workpiece loading / unloading area 24. The workpiece carrying-out means 17 is disposed between the workpiece carrying-in / out area 24 and the cleaning means 14, and is polished on the chuck table 52 positioned in the workpiece carrying-in / out area 24. The processed workpiece is transported to the cleaning means 14. Further, the polishing apparatus in the illustrated embodiment has a cleaning water injection nozzle 18 for cleaning the chuck table 52 at the center of the main part 21 of the apparatus housing 2. The cleaning water jet nozzle 18 jets cleaning water toward the polished workpiece held on the chuck table 52 when the chuck table mechanism 5 is positioned in the workpiece loading / unloading area 24. I do.
[0021]
The workpiece accommodated in the first cassette 11 is a semiconductor wafer on which the protective tape is mounted on the front side (the surface on which the circuit is formed) (therefore, the back side of the semiconductor wafer is positioned on the upper side). Is fine. The first cassette 11 containing such a semiconductor wafer as a workpiece is placed in a predetermined cassette loading area in the main portion 21 of the apparatus housing 2. When all of the unpolished semiconductor wafers stored in the first cassette 11 placed in the cassette loading area are unloaded, a new cassette containing a plurality of semiconductor wafers is used instead of the empty cassette 11. 11 is manually placed in the cassette loading area. On the other hand, when a predetermined number of polished semiconductor wafers are loaded into the second cassette 12 placed in a predetermined cassette unloading area in the main portion 21 of the apparatus housing 2, the second cassette 12 is manually moved. It is carried out and a new empty second cassette 12 is placed.
[0022]
The polishing apparatus in the illustrated embodiment is configured as described above, and its operation will be described below mainly with reference to FIG.
The semiconductor wafer as a workpiece before polishing stored in the first cassette 11 is transported by the vertical movement and the forward / backward movement of the workpiece transporting means 15 and is placed on the workpiece temporary mounting means 13. . The semiconductor wafer placed on the workpiece temporary mounting means 13 is positioned in the workpiece loading / unloading area 24 by the turning operation of the workpiece loading means 16 after centering is performed here. The chuck table mechanism 5 is mounted on the suction chuck 522 of the chuck table 52. A semiconductor wafer as a workpiece mounted on the suction chuck 522 of the chuck table 52 is suction-held on the suction chuck 522 by suction means (not shown).
[0023]
When the semiconductor wafer is sucked and held on the suction chuck 522 of the chuck table 52, the chuck table moving mechanism 56 (see FIG. 4) is operated to move the chuck table mechanism 5 in the direction indicated by the arrow 23a and position it in the polishing area 25. . When the chuck table mechanism 5 is positioned in the polishing area 25, as shown in FIGS. 6A and 6B, the center (P) of the semiconductor wafer W held on the chuck table 52 slightly moves the outer peripheral edge of the polishing grindstone 327. Is positioned beyond Next, the chuck table 52 is rotated at, for example, about 100 to 300 rpm, the servo motor 323 is driven to rotate the polishing tool 325 at 4000 to 7000 rpm, and the pulse motor 44 of the polishing unit feed mechanism 4 is rotated forward. Then, the polishing unit 3 is lowered or moved forward from the standby position indicated by the two-dot chain line in FIG. Then, as shown by the solid line in FIG. 6B, the polishing surface (lower surface) of the polishing grindstone 327 constituting the polishing tool 325 is placed on the back surface (polished surface) of the semiconductor wafer W on the chuck table 52 by a predetermined load (polishing). By pressing with a load, the surface to be polished of the semiconductor wafer W is polished. By polishing in this manner for a predetermined time, the back surface of the semiconductor wafer W is dry-polished by a predetermined amount by the action of the polishing grindstone 327, and residual processing distortion is removed.
[0024]
In the above-described polishing step, since the polishing grindstone 327 of the polishing tool 325 is made of a flexible felt, if the polishing grindstone 327 is pressed uniformly on the back surface (polished surface) of the semiconductor wafer W as a workpiece, The central region of the semiconductor wafer W is often polished, and the surface to be polished tends to be polished into a concave concave surface. However, in the present invention, since the holding surface 522a of the suction chuck 522 of the chuck table 52 holding the semiconductor wafer W as the workpiece is formed as a spherical concave curved surface, the holding surface 522a of the suction chuck 522 is The surface to be polished of the semiconductor wafer W held by suction is also a spherical concave curved surface. Therefore, even when the polishing is performed with the polishing grindstone 327 made of a soft felt, the pressing force of the semiconductor wafer W on the polished surface in the central region is lower than the pressing force on the outer peripheral region. The polishing effect on the central region and the polishing effect on the outer peripheral region are the same, and the semiconductor wafer W is polished to a uniform thickness. Since the semiconductor wafer W is polished to a uniform thickness in this manner, the problem that heat does not accumulate in the central portion and the central portion of the protective tape is melted is also solved. Further, in the illustrated embodiment, the polishing apparatus of the present invention can be configured only by replacing the chuck table of the existing polishing apparatus with the chuck table 52 in which the holding surface 522a is formed into a spherical concave surface.
[0025]
When the polishing step is completed as described above, the chuck table 52 is moved in the direction indicated by the arrow 23b and positioned in the workpiece loading / unloading area 24. When the chuck table 52 is positioned in the workpiece loading / unloading area 24, the cleaning water is sprayed from the cleaning water injection nozzle 18 to clean the polished surface of the polished semiconductor wafer held by the chuck table 52. Wash. Then, the suction holding of the semiconductor wafer held by the chuck table 52 is released. Next, the semiconductor wafer released from the suction holding is conveyed to the cleaning means 14 by the work carrying-out means 17. The semiconductor wafer transported to the cleaning means 14 is cleaned and spin-dried here. The semiconductor wafer cleaned and dried by the cleaning unit 14 is stored in a predetermined position of the second cassette 12 by the workpiece transfer unit 15.
[0026]
Next, another embodiment of the polishing apparatus according to the present invention will be described with reference to FIGS. FIG. 7 is a plan view showing the relationship between the chuck table 52 and the polishing tool 325 in the polishing area, and FIG. 8 is a side view thereof. In the embodiment shown in FIGS. 7 and 8, the same members as those in the embodiments shown in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof will be omitted.
In the polishing apparatus according to the embodiment shown in FIGS. 7 and 8, the holding surface 522a of the suction chuck 522 constituting the chuck table 52 is formed in a flat surface, and the polishing tool 325 is formed into a felt like the above-described embodiment. A felt grindstone in which grains are dispersed and fixed with an appropriate bonding agent is used. In this embodiment, as shown in FIG. 8, the rotating shaft 520 of the chuck table 52 and the rotating shaft of the polishing tool 325, that is, the rotating spindle 322, have a predetermined crossing angle (θ). Is set to 0.0001 to 0.002 radians. When the crossing angle (θ) is set to 0.0006 radian, when the diameter of the suction chuck 522 is 200 mm, the distance between the polishing surface (lower surface) of the polishing grindstone 327 and the center of the holding surface 522a of the suction chuck 522. Is about 60 μm larger than the distance between the polishing surface (lower surface) of the polishing grindstone 327 and the outer peripheral portion of the holding surface 522a of the suction chuck 522. With this configuration, even if the workpiece is polished with the polishing grindstone 327 made of a soft felt, the pressing force of the workpiece held on the holding surface 522a of the suction chuck 522 against the central region of the polished surface is reduced. Since the pressing force is lower than the pressing force on the outer peripheral region, the polishing action on the central portion of the surface to be polished of the workpiece and the polishing action on the outer peripheral portion become equal, and the workpiece is polished to a uniform thickness.
[0027]
【The invention's effect】
The polishing apparatus according to the present invention is configured as described above, and the holding surface of the chuck table is formed as a spherical concave curved surface, so that the unprocessed object held on the chuck table holding surface also has a spherical concave curved surface. Become. Therefore, even when the soft member is polished with a polishing grindstone in which abrasive grains are mixed, the pressing force on the central region of the polished surface of the workpiece is lower than the pressing force on the outer peripheral region. In the above, the polishing action on the central area and the polishing action on the outer peripheral area are equivalent. As a result, the workpiece can be polished to a uniform thickness. According to the present invention, the polishing apparatus of the present invention can be constituted by simply replacing the chuck table of the existing polishing apparatus with a chuck table having a holding surface formed with a concave spherical surface.
[0028]
Further, in the polishing apparatus according to the present invention, even when the holding surface of the chuck table is flat, the rotation axis of the chuck table and the rotation axis of the grinding wheel are configured with a predetermined intersection angle. Is larger than the distance between the polishing surface of the polishing grindstone and the outer peripheral portion of the holding surface of the chuck table. Therefore, even when the soft member is polished with a polishing grindstone in which abrasive grains are mixed, the pressing force on the central region of the polished surface of the workpiece is lower than the pressing force on the outer peripheral region. In the above, the polishing action on the central area and the polishing action on the outer peripheral area are equivalent. As a result, the workpiece can be polished to a uniform thickness.
[Brief description of the drawings]
FIG. 1 is a perspective view showing one embodiment of a polishing apparatus configured according to the present invention.
FIG. 2 is a perspective view showing a polishing tool constituting a polishing unit provided in the polishing apparatus shown in FIG. 1;
FIG. 3 is a perspective view showing a state of the polishing tool shown in FIG. 2 viewed from a lower surface side;
FIG. 4 is a perspective view showing a chuck table mechanism and a chuck table moving mechanism provided in the polishing apparatus shown in FIG. 1;
FIG. 5 is an enlarged cross-sectional view of a chuck table provided in the polishing apparatus shown in FIG.
FIG. 6 is an explanatory view showing a relationship between a chuck table and a polishing tool in a polishing area of the polishing apparatus shown in FIG. 1;
FIG. 7 is a plan view showing another embodiment of the polishing apparatus according to the present invention, showing a relationship between a chuck table and a polishing tool in a polishing area.
FIG. 8 is a side view of the chuck table and the polishing tool shown in FIG. 8;
[Explanation of symbols]
2: Device housing 3: Polishing unit 31: Moving base 32: Spindle unit 321: Spindle housing 322: Rotating spindle 323: Servo motor 324: Tool mounting member 325: Polishing tool 326: Support member 327: Polishing grindstone 4: Polishing unit Feeding mechanism 44: pulse motor 5: chuck table mechanism 51: support base 52: chuck table 53: servo motor 54: cover member 56: chuck table moving mechanism 61, 62: bellows means 11: first cassette 12: second Cassette 13: Workpiece temporary mounting means 14: Cleaning means 15: Workpiece transfer means 16: Workpiece carry-in means 17: Workpiece carry-out means 18: Washing water injection nozzle

Claims (6)

A chuck table having a holding surface for holding the workpiece, a chuck table mechanism having a driving means for rotating and driving the chuck table, and polishing the workpiece held on the holding surface of the chuck table; Polishing unit having a polishing member in which abrasive grains are mixed into a flexible member for driving, a polishing unit having a driving means for rotating the polishing wheel, and moving the polishing unit in a direction perpendicular to the holding surface of the chuck table. A polishing unit having a polishing unit feed mechanism,
The holding surface of the chuck table is formed as a spherical concave curved surface,
A polishing apparatus characterized in that: The polishing apparatus according to claim 1, wherein a radius of curvature of the spherical concave surface is set to 100 to 1000 m. The polishing method according to claim 1 or 2, wherein the polishing grindstone is a felt grindstone in which abrasive grains are dispersed in felt and fixed with an appropriate bonding agent. A chuck table having a holding surface for holding the workpiece, a chuck table mechanism having a driving means for rotating and driving the chuck table, and polishing the workpiece held on the holding surface of the chuck table; Polishing unit including a polishing wheel in which abrasive grains are mixed in a flexible member for driving, a driving unit for rotating and driving the polishing wheel, and moving the polishing unit in a direction perpendicular to the holding surface of the chuck table. A polishing unit having a polishing unit feed mechanism,
The rotation axis of the chuck table and the rotation axis of the grinding wheel are configured with a predetermined intersection angle,
A polishing apparatus characterized in that: The polishing apparatus according to claim 4, wherein an intersection angle between the rotation axis of the chuck table and the rotation axis of the polishing grindstone is set to 0.0001 to 0.002 radians. The polishing apparatus according to claim 4, wherein the polishing grindstone is a felt grindstone in which abrasive grains are dispersed in felt and fixed with an appropriate bonding agent.

Images