Creep Feed Grinding Equipment

Abstract

To resolve poor conditions of a bottom surface of each abrasive wheel without deteriorating working efficiency in creep feed grinding.SOLUTION: A creep feed grinding device includes: a chuck table; a grinding unit which has a spindle and in which a grinding wheel including multiple abrasive wheels annularly arranged on one surface side of an annular base is attached to a lower end side of the spindle and an outer diameter of a trajectory of the multiple abrasive wheels during rotation of the spindle is larger than an outer diameter of the chuck table; a moving mechanism which relatively moves the chuck table and the grinding unit along a predetermined direction orthogonal to a longitudinal direction of the spindle; and a bottom surface state adjustment mechanism which is located at the outer side of a relative moving area of the chuck table when the chuck table and the grinding unit are relatively moved along the predetermined direction, and which cleans or corrects, or cleans and corrects a bottom surface of each abrasive wheel which contacts with a workpiece during creep feed grinding to adjust a state of the bottom surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a creep feed grinding device that grinds a workpiece with a grinding wheel while moving a grinding unit having a spindle with a grinding wheel attached to the lower end and a chuck table that holds the workpiece by suction relative to each other in a direction perpendicular to the longitudinal direction of the spindle. [Background technology]

[0002] Electronic devices such as mobile phones generally include device chips having devices such as integrated circuits (ICs). When manufacturing device chips, for example, first, a plurality of planned dividing lines (streets) are set in a grid pattern on the surface of a wafer made of a semiconductor such as silicon, and devices are formed in each of the rectangular areas partitioned by the plurality of streets.

[0003] Next, a cutting device is used to cut the wafer along each street to separate the wafer into individual device chips. However, in recent years, in order to reduce the size and weight of device chips, after devices are formed on the front side of the wafer, the back side of the wafer is ground to reduce the finished thickness of the device chips.

[0004] For example, a creep feed grinding machine is used to grind wafers (see Patent Document 1). The creep feed grinding machine is equipped with a disk-shaped chuck table having a holding surface that holds the workpiece by suction. A grinding unit is disposed above the holding surface.

[0005] The grinding unit has a cylindrical spindle whose longitudinal direction is generally perpendicular to the holding surface. The longitudinal direction of the spindle is generally parallel to the Z-axis direction (e.g., vertical direction) of the creep feed grinding machine. An annular grinding wheel is attached to the lower end of the spindle via a disk-shaped mount.

[0006] The grinding wheel has an annular base. On the underside of the base, multiple grinding stones are arranged at approximately equal intervals along the circumferential direction of the base. When the spindle is rotated, the grinding wheel rotates, and the grinding stones move along the underside of the base, forming an annular grinding surface.

[0007] When performing creep feed grinding, the front side of the workpiece is held by suction with the holding surface, exposing the back side of the workpiece upward, and the height of the grinding unit is adjusted so that the grinding surface is at a height slightly lower than the back side of the workpiece.

[0008] In this state, creep feed grinding is performed on the backside of the wafer by moving the chuck table along the X-axis direction, which is perpendicular to the Z-axis direction. In creep feed grinding, the load on the outer peripheral side of the grinding wheel in the X-axis direction tends to be greater than the load on the bottom surface of the grinding wheel in the Z-axis direction.

[0009] In contrast, in infeed grinding, in which the grinding unit is fed downward along the Z-axis while rotating a chuck table located below the grinding unit, the load on the bottom surface of the grinding wheel in the Z-axis direction tends to be greater than the load on the outer peripheral side surface of the grinding wheel in the X-axis direction.

[0010] In creep feed grinding, wear on the bottom side of the grinding wheel is less than that in in-feed grinding depending on the load during grinding, so poor conditions such as clogging are more likely to occur on the bottom side of the grinding wheel. Creep When feed grinding is performed, poor condition of the bottom surface is likely to occur. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-103192 Summary of the Invention [Problem to be solved by the invention]

[0012] However, if a dressing process is performed to dress the grinding wheel separately from the grinding process of the workpiece in order to eliminate poor conditions, the work efficiency in creep feed grinding will decrease.

[0013] The present invention has been made in view of the above problems, and has as its object to eliminate the poor condition of the bottom surface of the grinding wheel in creep feed grinding without reducing the work efficiency. [Means for solving the problem]

[0014] According to one aspect of the present invention, a creep feed grinding device includes a chuck table having a holding surface for suction-holding a workpiece, a grinding wheel having a spindle and an annular base and a plurality of grinding wheels arranged in an annular shape on one side of the base, the grinding wheel being attached to the lower end side of the spindle, and the outer diameter of the trajectory of the plurality of grinding wheels when the spindle rotates is larger than the outer diameter of the chuck table, and a grinding unit having a chuck table having a holding surface for suction-holding a workpiece, the grinding wheel being attached to the lower end side of the spindle, the grinding wheel being attached to the lower end side of the spindle, the outer diameter of the trajectory of the plurality of grinding wheels when the spindle rotates being larger than the outer diameter of the chuck table, and a grinding unit having a chuck table having a holding surface for suction-holding a workpiece, the grinding wheel being attached to the lower end side of the spindle ... No. 1 a moving mechanism that moves the chuck table and the grinding unit relatively along a predetermined direction; No. 1 A relative movement area of ​​the chuck table when the chuck table is moved relatively in a predetermined direction In a plan view, the movement area in a second predetermined direction perpendicular to the first predetermined direction is The bottom surface of each grinding wheel is located outside the workpiece during creep feed grinding. At least one of removing grinding chips, sharpening and shape correction is performed on the Thus, a creep feed grinding machine is provided which is equipped with a bottom surface condition adjustment mechanism that adjusts the condition of the bottom surface.

[0015] Preferably, the bottom surface condition adjustment mechanism has a first nozzle, and when creep feed grinding is performed on the workpiece by the grinding unit, high-pressure water is sprayed from the first nozzle onto the bottom surface.

[0016] Preferably, the bottom surface condition adjustment mechanism has a second nozzle, and when the grinding unit performs creep feed grinding on the workpiece, high-pressure water containing abrasive grains is sprayed from the second nozzle onto the bottom surface.

[0017] Preferably, the bottom surface condition adjustment mechanism has a third nozzle that sprays a mixture of two fluids, water and air, and when the grinding unit performs creep feed grinding on the workpiece, the two fluids are sprayed from the third nozzle onto the bottom surface.

[0018] Preferably, the bottom surface condition adjusting mechanism has a dressing portion, and brings the dressing portion into contact with the bottom surface when creep feed grinding is performed on the workpiece by the grinding unit. By doing so, at least one of removing grinding chips, dressing and shape correction is performed on the bottom surface of each grinding wheel. .

[0019] Preferably, the bottom surface condition adjusting mechanism has a brush, and brings the brush into contact with the bottom surface when creep feed grinding is performed on the workpiece by the grinding unit. By doing so, at least one of removing grinding chips, dressing and shape correction is performed on the bottom surface of each grinding wheel. .

[0020] Preferably, the bottom surface condition adjusting mechanism has a condenser of a laser beam irradiating unit, and irradiates the bottom surface with a laser beam from the condenser when creep feed grinding is performed on the workpiece by the grinding unit. By doing so, at least one of removing grinding chips, dressing and shape correction is performed on the bottom surface of each grinding wheel. . Preferably, the creep feed grinding device further includes an additional bottom surface condition adjustment mechanism that is positioned to sandwich the moving area between itself and the bottom surface condition adjustment mechanism in the second predetermined direction, and that adjusts the condition of the bottom surface by performing at least one of removing grinding chips, sharpening, and shape correction on the bottom surface of each grinding wheel. [Effects of the Invention]

[0021] A creep feed grinding apparatus according to one aspect of the present invention includes a bottom surface condition adjustment mechanism that is disposed outside the relative movement range of the chuck table with respect to the grinding unit, and that adjusts the condition of the bottom surface of each grinding wheel by cleaning or adjusting, or both cleaning and adjusting, the bottom surface of each grinding wheel during creep feed grinding.

[0022] For example, the bottom surface condition adjustment mechanism cleans or repairs, or both cleans and repairs, the bottom surface of the grinding wheel located outside the chuck table during creep feed grinding of a workpiece, thereby eliminating poor conditions such as clogging on the bottom surface. This makes it possible to eliminate poor conditions on the bottom surface of the grinding wheel during creep feed grinding without reducing work efficiency. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a partial cross-sectional side view of a creep feed grinding device. [Figure 2] FIG. 1 is a top view showing creep feed grinding. [Figure 3] FIG. 3(A) is a partial cross-sectional side view of a workpiece etc. at the start of creep feed grinding, and FIG. 3(B) is a partial cross-sectional side view of the workpiece etc. after creep feed grinding. [Figure 4] FIG. 1 is a perspective view showing creep feed grinding. [Figure 5] FIG. 2 is a top view of a creep feed grinding device according to a first modified example of the first embodiment. [Figure 6] FIG. 2 is a perspective view of a creep feed grinding device according to a first modified example of the first embodiment. [Figure 7] FIG. 10 is a top view of a creep feed grinding device according to a second modified example of the first embodiment. [Figure 8] FIG. 4 is a partial cross-sectional side view of a creep feed grinding device according to a second embodiment. [Figure 9] FIG. 10 is a partial cross-sectional side view of a creep feed grinding device according to a third embodiment. [Figure 10] FIG. 10 is a partial cross-sectional side view of a creep feed grinding device according to a fourth embodiment. [Figure 11] FIG. 10 is a partial cross-sectional side view of a creep feed grinding device according to a fifth embodiment. [Figure 12] FIG. 10 is a partial cross-sectional side view of a creep feed grinding device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a partial cross-sectional side view showing an example of a creep feed grinding apparatus 2. Note that the X-axis direction and Y-axis direction in Fig. 1 are perpendicular to each other on a horizontal plane, and the Z-axis direction is perpendicular to the X-axis direction and Y-axis direction.

[0025] The creep feed grinding device 2 includes a base 4 that supports or houses each of the components that make up the creep feed grinding device 2. A rectangular parallelepiped recess 4a having a longitudinal portion in the X-axis direction is formed on the upper surface of the base 4.

[0026] A disk-shaped chuck table 6 is provided inside the recess 4a. The chuck table 6 has a disk-shaped frame 8 made of ceramics. A disk-shaped recess 8a is formed in the upper part of the frame 8.

[0027] A circular porous plate 10 made of porous ceramics is fixed in the recess 8a. The upper surface of the frame 8 and the upper surface of the porous plate 10 are substantially flush with each other and form a holding surface 6a that is substantially parallel to the X and Y axis directions.

[0028] A flow path 8b is formed in the frame 8 to connect the porous plate 10 to a suction source (not shown) such as an ejector. When negative pressure is transmitted to the porous plate 10 through the flow path 8b, the workpiece 11 (see FIG. 2) placed on the holding surface 6a is sucked and held on the holding surface 6a.

[0029] The chuck table 6 is supported by a rectangular X-axis direction moving plate 12. The X-axis direction moving plate 12 is slidably supported by a pair of guide rails (not shown) arranged substantially parallel to the X-axis direction. A nut portion 14 is provided on the underside of the X-axis direction moving plate 12.

[0030] A screw shaft 16 is disposed along the X-axis direction between a pair of guide rails and is rotatably connected to the nut portion 14. A drive source 18 such as a motor for rotating the screw shaft 16 is connected to one end of the screw shaft 16.

[0031] When the screw shaft 16 is rotated by the drive source 18, the chuck table 6 moves along the X-axis direction together with the nut portion 14. The X-axis direction moving plate 12, the nut portion 14, the screw shaft 16, the drive source 18, etc. constitute an X-axis direction moving mechanism (moving mechanism) 20.

[0032] A rectangular parallelepiped support structure 22 is provided behind (one side in the X-axis direction) the X-axis movement mechanism 20 so as to protrude above the opening of the recess 4a. The support structure 22 is formed integrally with the base 4, and a grinding feed unit 24 is provided on the front side (the other side in the X-axis direction) of the support structure 22.

[0033] The grinding feed unit 24 is fixed to the front side surface of the support structure 22 and includes a pair of guide rails 26 arranged along the Z-axis direction. A cylindrical holding member 28 with a bottom is fixed to the front side of the pair of guide rails 26 so as to be slidable in the Z-axis direction.

[0034] A nut portion 30 is provided on the rear side of the holding member 28. A screw shaft 32 is rotatably connected to the nut portion 30. The screw shaft 32 is disposed along the Z-axis direction between the pair of guide rails 26.

[0035] A drive source 34 such as a motor for rotating the screw shaft 32 is connected to the upper end of the screw shaft 32. When the screw shaft 32 is rotated by the drive source 34, the holding member 28 moves along the Z-axis direction.

[0036] The holding member 28 is provided with a grinding unit 36. The grinding unit 36 ​​has a cylindrical spindle housing 38 disposed within the holding member 28. The spindle housing 38 is supported by the bottom wall of the holding member 28.

[0037] The spindle housing 38 rotatably accommodates a part of a cylindrical spindle 40 whose longitudinal direction is arranged in the Z-axis direction (predetermined direction). A rotation drive source such as a motor is provided at the upper end of the spindle 40.

[0038] The lower end of the spindle 40 protrudes downward below the holding member 28 through a through-opening formed in the bottom wall of the holding member 28. An annular grinding wheel 44 having an outer diameter approximately the same as that of the mount 42 is attached to the lower end of the spindle 40 via a disk-shaped mount 42.

[0039] The grinding wheel 44 has an annular base 46 made of metal such as an aluminum alloy. The upper surface of the base 46 is fixed to the lower surface of the mount 42 by fixing members (not shown) such as screws. A plurality of grinding stones 48 are arranged on the lower surface (one surface) 46a of the base 46 at approximately equal intervals along the circumferential direction of the base 46 (i.e., annularly).

[0040] Each of the multiple grinding wheels 48 has an approximately block shape and includes abrasive grains made of diamond or cBN (cubic boron nitride), etc., and a bonding material (bond material) made of metal, resin, ceramic, etc. that secures each abrasive grain.

[0041] When the grinding feed unit 24 is operated, the grinding unit 36 ​​and the chuck table 6 move relatively along the Z-axis direction, thereby adjusting the height position of the grinding unit 36 ​​(grinding wheel 44 and grinding stone 48).

[0042] When the spindle 40 is rotated, an annular grinding surface 48a (see FIG. 3A) is formed by the loci of the bottom surfaces 48d of the multiple grinding stones 48. Note that FIG. 3A shows the position of the grinding surface 48a in the Z-axis direction.

[0043] 2 is a top view showing creep feed grinding. The outer diameter 48b of the trajectory of the multiple grinding wheels 48 when the spindle 40 rotates (i.e., the outer diameter 48b of the grinding surface 48a) is larger than the outer diameter 6b of the chuck table 6.

[0044] For example, outer diameter 48b is 500 mm and outer diameter 6b is 300 mm, but outer diameter 48b only needs to be 60 mm or more larger than outer diameter 6b. Furthermore, in the XY plane view, center 48c of outer diameter 48b of grinding surface 48a and center 6c of outer diameter 6b of chuck table 6 are arranged on a straight line along the X-axis direction.

[0045] When the grinding wheel 44 (grinding unit 36) and the chuck table 6 are moved relative to each other along the X-axis direction (predetermined direction) to a position directly below the grinding wheel 44, the chuck table 6 is positioned inside the inner circumference of the grinding wheel 44 when viewed from above, as shown by the dashed line in Figure 2.

[0046] The creep feed grinding apparatus 2 of the first embodiment is provided with a bottom surface condition adjustment unit 50. The bottom surface condition adjustment unit 50 has a first nozzle (bottom surface condition adjustment mechanism) 52 arranged outside in the Y-axis direction of a relative movement area B (see FIG. 2) of the chuck table 6 with respect to the grinding unit 36.

[0047] The position of the first nozzle 52 is fixed relative to the grinding unit 36. For example, the first nozzle 52 is fixed to the base 4 and disposed in one location directly below the grinding surface 48a. The distance between the first nozzle 52 and the grinding wheel 48 located directly above the first nozzle 52 is adjusted in advance according to the speed of the high-pressure water 54 sprayed from the first nozzle 52, etc.

[0048] 3(A), a high-pressure water supply source 56 is connected to the first nozzle 52. The high-pressure water supply source 56 has a pump (not shown) that pressurizes the supplied pure water to a predetermined pressure.

[0049] During creep feed grinding, the first nozzle 52 adjusts the condition of the bottom surface 48d (see Figure 3(A)) of the grinding wheel 48 by spraying high-pressure water 54, such as pure water, pressurized to 0.1 MPa or more (for example, a predetermined value of 2 MPa or more and 13 MPa or less) upward.

[0050] When creep feed grinding is performed on the workpiece 11, first, the front surface 11a side of the workpiece 11 is held by suction so that the back surface 11b is exposed (see the workpiece 11 shown by the solid line in FIG. 2).

[0051] If a device is formed on the surface 11a, a resin protective tape is attached to the surface 11a to protect the device, and then the surface 11a is held by suction in the carry-in / carry-out area A1 of the chuck table 6 located in front of the creep feed grinding device 2.

[0052] After suction holding, the spindle 40 is rotated at a predetermined rotation speed, and the grinding feed unit 24 is used to adjust the height position of the grinding surface 48a between the holding surface 6a and the back surface 11b so that the bottom surface 48d of the grinding wheel 48 comes into contact with the back surface 11b (see Figure 3(A)).

[0053] The rotation speed of the spindle 40 may be set appropriately depending on the outer diameter 48b. For example, if the outer diameter 48b is 500 mm, the rotation speed is set to 2000 rpm, and if the outer diameter 48b is 300 mm, the rotation speed is set to 3200 rpm.

[0054] After adjusting the height position of the grinding surface 48a, the spraying of high-pressure water 54 from the first nozzle 52 begins, and creep feed grinding is then started by starting to move the chuck table 6. Figure 3(A) is a partial cross-sectional side view of the workpiece 11 etc. at the start of creep feed grinding.

[0055] During creep feed grinding, the chuck table 6 is moved by the X-axis direction moving mechanism 20 to a predetermined area A2 on the rear side of the creep feed grinding device 2 at a predetermined moving speed (for example, 10 mm / s).

[0056] In the first embodiment, the predetermined area A2 is located directly below the grinding unit 36. The chuck table 6 that has moved to the predetermined area A2 is located inside the inner periphery of the grinding surface 48a in the XY plane view (see FIG. 2).

[0057] In this way, the back surface 11b is ground by the side and bottom surfaces 48d of the grinding wheel 48, and multiple arc-shaped saw marks 11c (see FIG. 2) are formed along the processing feed direction. FIG. 3(B) is a partial cross-sectional side view of the workpiece 11, etc. after creep feed grinding in one pass.

[0058] One pass means one operation in which the chuck table 6 and the grinding unit 36 ​​are moved relative to each other in a predetermined direction until the chuck table 6, which is located outside the grinding wheel 44 in the X-Y plane view, is positioned directly below the grinding wheel 44.

[0059] In the first embodiment, one pass refers to the movement of the chuck table 6 from the outside of the grinding wheel 44 to directly below it in the direction from the loading / unloading area A1 (see Figure 3(A)) toward the specified area A2 (see Figure 3(B)) along the X-axis direction.

[0060] In the first embodiment, during creep feed grinding in one pass, high-pressure water 54 is sprayed from a first nozzle 52 onto a bottom surface 48d of a grinding wheel 48, thereby cleaning or conditioning the bottom surface 48d, or cleaning and conditioning the bottom surface 48d with the high-pressure water 54. Figure 4 is a perspective view showing creep feed grinding.

[0061] In this embodiment, by spraying high-pressure water 54 onto the bottom surface 48d during creep feed grinding, it is possible to remove grinding debris that may cause clogging on the bottom surface 48d side of the grinding wheel 48, sharpen the grinding wheel 48, and / or modify the shape of the grinding wheel 48. This eliminates poor conditions on the bottom surface 48d during creep feed grinding.

[0062] Therefore, poor conditions on the bottom surface 48d can be eliminated without reducing work efficiency during creep feed grinding. Also, by locating the first nozzle 52 outside the relative movement area B of the chuck table 6, the space outside the movement area B can be effectively utilized.

[0063] Note that creep feed grinding may be performed in two or more passes to thin the workpiece 11 down to the desired finishing thickness. When performing creep feed grinding in the second pass, after the chuck table 6 has moved to directly below the grinding unit 36 ​​in the first pass, the grinding unit 36 ​​is temporarily raised to a level where the grinding wheel 48 does not come into contact with the workpiece 11.

[0064] Then, the chuck table 6 is moved toward the load-in / load-out area A1 until it is positioned so that it does not overlap the grinding wheel 44 in the X-Y plane view. After that, the chuck table 6 is moved in the X-axis direction from the load-in / load-out area A1 toward the predetermined area A2, thereby performing creep feed grinding for the second pass.

[0065] The third pass and thereafter can be performed in the same manner. During creep feed grinding, the spraying of high-pressure water 54 from the first nozzle 52 continues, but the spraying of high-pressure water 54 is stopped while the chuck table 6 is being moved toward the load-in / load-out area A1.

[0066] Incidentally, the first nozzles 52 may be arranged in two or more locations directly below the grinding surface 48a as long as they do not interfere with the movement area B. For example, the first nozzles 52 are arranged in two or more locations on one side or both sides located outside the movement area B in the Y-axis direction.

[0067] In particular, by arranging the first nozzles 52 at two locations on either side of the center 48c of the outer diameter 48b, the bottom surface 48d side of the grinding wheel 48 can be cleaned or repaired, or both, with the high-pressure water 54 immediately before and immediately after contact with the workpiece 11, regardless of the rotation direction of the spindle 40. Therefore, the degree of freedom of rotation of the spindle 40 can be ensured.

[0068] Next, a first modified example of the first embodiment will be described with reference to Figures 5 and 6. Figure 5 is a top view of a creep feed grinding apparatus 2a according to the first modified example, and Figure 6 is a perspective view of the creep feed grinding apparatus 2a according to the first modified example.

[0069] The chuck table 6 of the first modified example is always stationary and is not moved by the X-axis direction moving mechanism 20. In contrast, the support structure 22 to which the grinding feed unit 24 is fixed can be moved in the X-axis direction by a moving mechanism similar to the X-axis direction moving mechanism 20.

[0070] The movement mechanism has an X-axis direction moving plate (not shown), and the support structure 22 is supported by this X-axis direction moving plate. The first nozzle 52 is supported by the holding member 28 or the X-axis direction moving plate. On the board Since it is fixed, it moves in the X-axis direction together with the support structure 22. Other points are the same as those in the first embodiment.

[0071] In the first modified example, during creep feed grinding, it is also possible to remove grinding debris, sharpen the grinding wheel 48, and / or modify the shape of the grinding wheel 48. This makes it possible to eliminate poor conditions of the bottom surface 48d during creep feed grinding without reducing work efficiency.

[0072] Next, a second modified example of the first embodiment will be described. Fig. 7 is a top view of a creep feed grinding apparatus 2b according to the second modified example of the first embodiment. In the second modified example, the chuck table 6 is always stationary, and the support structure 22 to which the grinding feed unit 24 is fixed moves in the X-axis direction.

[0073] However, in the second modified example, the position of the first nozzle 52 is fixed near the chuck table 6 and does not move in the X-axis direction. The first nozzle 52 in the second modified example is disposed directly below the relative movement area of ​​the grinding surface 48a with respect to the chuck table 6, outside the movement area B on a line parallel to the Y-axis direction passing through the center 6c (see FIG. 2) in the XY plane view.

[0074] This is a difference from the first modified example, but other points are the same as those of the first modified example. In the second modified example, at least one of removing grinding debris, sharpening the grinding wheel 48, and correcting the shape of the grinding wheel 48 can also be performed during creep feed grinding.

[0075] Next, a second embodiment will be described. Fig. 8 is a partial cross-sectional side view of a creepfeed grinding device 62a according to the second embodiment. The bottom surface condition adjustment unit 50a of the second embodiment has a second nozzle (bottom surface condition adjustment mechanism) 52a whose position relative to the grinding unit 36 ​​is fixed.

[0076] 8 is fixed to the base 4, and is disposed at one location directly below the grinding surface 48a located outside the relative movement area B of the chuck table 6. The second nozzle 52a sprays high-pressure water 54a2, such as pure water, containing abrasive grains 54a1 and pressurized to 0.1 MPa or more (for example, a predetermined value of 2 MPa or more and 13 MPa or less), upward.

[0077] The average particle size of the abrasive grains 54a1 used is smaller than the average particle size of the abrasive grains that make up the grinding wheel 48. 2 Nozzle 52 a An abrasive-containing high-pressure water supply source 56a is connected to the

[0078] The abrasive-containing high-pressure water supply source 56a includes a tank (not shown) for storing pure water mixed with abrasive grains 54a1, and a pump (not shown) for increasing the pressure of the pure water containing abrasive grains 54a1 supplied from the tank to a predetermined level.

[0079] In the second embodiment, during creep feed grinding, high-pressure water 54 containing abrasive grains 54a1 is sprayed from the second nozzle 52a onto the bottom surface 48d of the grinding wheel 48, and the bottom surface 48d is cleaned or repaired, or both cleaned and repaired, with high-pressure water 54a2 containing abrasive grains 54a1.

[0080] This makes it possible to perform at least one of removing grinding debris, sharpening the grinding wheel 48, and correcting the shape of the grinding wheel 48 on the bottom surface 48d side of the grinding wheel 48. Therefore, poor condition of the bottom surface 48d can be resolved without reducing work efficiency in creep feed grinding.

[0081] 8 is disposed in one location directly below the grinding surface 48a, the second nozzles 52a may be disposed in two or more locations directly below the grinding surface 48a as long as they do not interfere with the relative movement area B of the chuck table 6. The second nozzles 52a may also be disposed in two or more locations on one side or both sides located outside the movement area B in the Y-axis direction.

[0082] In particular, by arranging the second nozzles 52a at two locations on either side of the center 48c of the outer diameter 48b, it is possible to ensure the degree of freedom of rotation of the spindle 40. Note that the first or second modified example described above may also be applied to the creep feed grinding device 62a.

[0083] Next, a third embodiment will be described. Fig. 9 is a partial cross-sectional side view of a creepfeed grinding device 62b according to the third embodiment. A bottom surface condition adjustment unit 50b of the third embodiment has a third nozzle (bottom surface condition adjustment mechanism) 52b whose position relative to the grinding unit 36 ​​is fixed.

[0084] 9 is fixed to the base 4 and is disposed at one location directly below the grinding surface 48a outside the movement area B. Two-fluid 54b, which is a mixture of pure water 54b1 and air 54b2, is sprayed upward from the third nozzle 52b.

[0085] For example, pure water 54b1 pressurized to 0.8 MPa and air 54b2 pressurized to 0.3 MPa are independently supplied to the third nozzle 52b, mixed in the third nozzle 52b, and then sprayed upward as two fluids 54b.

[0086] A dual-fluid supply source 56b is connected to the third nozzle 52b via a conduit for pure water 54b1 and a conduit for air 54b2. The dual-fluid supply source 56b includes a pure water supply source (not shown) having a pump (not shown) for supplying pressurized pure water 54b1 and a tank (not shown) in which the pure water 54b1 is stored.

[0087] Furthermore, the dual fluid supply source 56b includes an air supply source (not shown) having a pump (not shown) for supplying pressurized air 54b2 and a tank (not shown) in which the air 54b2 is stored.

[0088] In the third embodiment, during creep feed grinding, the bottom surface 48d is cleaned or repaired, or both cleaned and repaired, by injecting the dual-fluid 54b from the third nozzle 52b onto the bottom surface 48d of the grinding wheel 48.

[0089] For example, by injecting the two-fluid 54b onto the bottom surface 48d side, it is possible to remove grinding debris, sharpen the grinding wheel 48, and / or correct the shape of the grinding wheel 48 on the bottom surface 48d side of the grinding wheel 48. Therefore, poor condition of the bottom surface 48d can be resolved without reducing work efficiency.

[0090] 9 is disposed in one location directly below the grinding surface 48a outside the movement region B, but the third nozzles 52b may be disposed in two or more locations directly below the grinding surface 48a. Also, the third nozzles 52b may be disposed in two or more locations on one or both sides located outside the movement region B in the Y-axis direction.

[0091] In particular, by arranging the third nozzles 52b at two locations on either side of the center 48c of the outer diameter 48b, it is possible to ensure the degree of freedom of rotation of the spindle 40, as described above. Note that the creep feed grinding device 62b may also employ the first or second modified example described above.

[0092] Next, a fourth embodiment will be described. Fig. 10 is a partial cross-sectional side view of a creep feed grinding apparatus 62c according to the fourth embodiment. The bottom surface condition adjustment unit 50c of the fourth embodiment has a disk-shaped dressing portion (bottom surface condition adjustment mechanism) 52c1 whose position relative to the grinding unit 36 ​​is fixed.

[0093] The dressing unit 52c1 is supported and fixed by a cylindrical base member 52c2. The base member 52c2 is fixed to the base 4 via an elevating mechanism (not shown) that raises and lowers the base member 52c2 along the Z-axis direction. The dressing unit 52c1 is disposed outside the movement region B, at one location directly below the grinding surface 48a.

[0094] The dressing portion 52c1 has, for example, a diameter of 1 cm to 5 cm and a thickness of 1 mm to 5 mm. The dressing portion 52c1 is sometimes called a dressing board. The diameter of the dressing portion 52c1 is appropriately selected depending on the segment width of the grinding wheel 48, etc.

[0095] The dressing portion 52c1 has a binder such as a vitrified bond, and abrasive grains such as white alundum (WA) and green carbon (GC) fixed by the binder.

[0096] The lifting mechanism raises the dressing portion 52c1 so that the height position of the upper surface of the dressing portion 52c1 matches the height position of the grinding surface 48a when creep feed grinding begins, and when grinding is not being performed, such as during maintenance, the lifting mechanism places the dressing portion 52c1 in a predetermined lowered position so that it does not come into contact with the bottom surface 48d.

[0097] The lifting mechanism has two positions: a raised position and a lowered position. Dressing part 52c In addition to a drive unit such as an air cylinder that positions the base member 52c2, a ball screw type moving unit that finely adjusts the height position of the base member 52c2 in accordance with wear of the dressing portion 52c1 may be provided.

[0098] In the fourth embodiment, during creep feed grinding, the bottom surface 48d is cleaned or repaired, or both, by bringing the dressing portion 52c1 into contact with the bottom surface 48d of the grinding wheel 48. For example, at least one of the removal of grinding debris, the dressing of the grinding wheel 48, and repair of the shape of the grinding wheel 48 can be performed on the bottom surface 48d side.

[0099] Therefore, poor condition of the bottom surface 48d can be eliminated without reducing work efficiency during creep feed grinding. Although the dressing portion 52c1 in Fig. 10 is disposed outside the movement area B and in one location directly below the grinding surface 48a, it may be disposed in two locations directly below the grinding surface 48a.

[0100] Furthermore, the dressing part 52c1 may be disposed in two or more locations on one or both sides located outside the movement area B in the Y-axis direction. This reduces the load on one dressing part 52c1 compared to disposing the dressing part 52c1 in one location, thereby reducing the frequency of replacing the dressing part 52c1.

[0101] In particular, by arranging the dressing portions 52c1 at two locations on either side of the center 48c of the outer diameter 48b, it is possible to ensure the degree of freedom of rotation of the spindle 40. Note that the first or second modified example described above may also be applied to the creep feed grinding device 62c.

[0102] Next, a fifth embodiment will be described. Fig. 11 is a partial cross-sectional side view of a creep feed grinding device 62d according to the fifth embodiment. A bottom surface condition adjustment unit 50d of the fifth embodiment has a brush (bottom surface condition adjustment mechanism) 52d whose position relative to the grinding unit 36 ​​is fixed.

[0103] The brush 52d of this embodiment is a so-called cylindrical brush, and includes bristles 52d1 made of resin such as polyamide or polyester, and a cylindrical portion 52d2 that secures one end of the bristles 52d1 in a bundled state. Note that the brush 52d is not limited to a cylindrical brush, and may be a brush of another type.

[0104] 11 is fixed to the base 4, and is disposed in one location directly below the grinding surface 48a outside the movement area B. A lifting mechanism (not shown) that moves the brush 52d up and down along the Z-axis direction is connected to the brush 52d.

[0105] The lifting mechanism raises the brush 52d so that the position of the upper end of the bristles 52d1 is aligned with the height of the grinding surface 48a when creep feed grinding begins, and when grinding is not being performed, such as during maintenance, the brush 52d is placed in a lowered position so that the bristles 52d1 do not come into contact with the bottom surface 48d.

[0106] In the fifth embodiment, during creep feed grinding, the brush 52d cleans or repairs, or both, the bottom surface 48d by bringing the bristles 52d1 into contact with the bottom surface 48d of the grinding wheel 48. For example, at least one of the removal of grinding debris, the sharpening of the grinding wheel 48, and repairing the shape of the grinding wheel 48 can be performed on the bottom surface 48d side.

[0107] Therefore, poor conditions on the bottom surface 48d can be eliminated without reducing work efficiency during creep feed grinding. Brush 52d is disposed outside of movement area B, in one location directly below grinding surface 48a, but may be disposed in two or more locations directly below grinding surface 48a.

[0108] The brushes 52d may be arranged in two or more locations on one or both sides located outside the movement area B in the Y-axis direction. In particular, by arranging the brushes 52d in two locations on either side of the center 48c of the outer diameter 48b, the degree of freedom of rotation of the spindle 40 can be ensured as described above. Note that the first or second modified example described above may also be applied to the creep feed grinding device 62d.

[0109] Next, a sixth embodiment will be described. Fig. 12 is a partial cross-sectional side view of a creep feed grinding device 62e according to the sixth embodiment. A bottom surface condition adjustment unit 50e of the sixth embodiment has a laser beam irradiation unit 52e.

[0110] The laser beam irradiation unit 52e has a laser oscillator 52e1 that irradiates a pulsed laser beam L. The laser oscillator 52e1 has a pulse generator (not shown) for controlling pulse characteristics of the laser beam L such as the pulse width and repetition frequency.

[0111] A pulse generator controls the light emission of the laser diode, and the light emitted from the laser diode is amplified by a rare-earth doped fiber (e.g., Yb-doped fiber), thereby forming a pulsed laser beam L having a predetermined wavelength (e.g., 1030 nm).

[0112] The laser beam L emitted from the laser oscillator 52e1 is reflected by a mirror 52e2, and then converged on the bottom surface 48d of the grinding wheel 48 via a lens 52e4 provided in a condenser (bottom surface state adjustment mechanism) 52e3.

[0113] The lens 52e4 is, for example, a cylindrical lens, and when focusing the laser beam L on the bottom surface 48d, it shapes the laser beam L into a line having a predetermined length corresponding to the segment width of the grinding wheel 48 (i.e., the diameter dimension of the grinding wheel 44).

[0114] The position of the condenser 52e3 relative to the grinding unit 36 ​​is fixed, and the laser beam L, which has been shaped to be focused into a line, is irradiated onto the bottom surface 48d of the grinding stone 48, for example, in the radial direction of the grinding wheel 44, so as to cross the bottom surface 48d.

[0115] By focusing the laser beam L linearly, the laser beam L can be irradiated almost evenly over the entire bottom surface 48d of each grinding stone 48 when the grinding wheel 44 rotates, compared to when the laser beam L is focused at a single point like a spherical lens.

[0116] 12 is fixed to the base 4, and the condenser 52e3 is disposed at one location directly below the grinding surface 48a outside the movement area B. The laser processing conditions using the laser beam irradiation unit 52e are set, for example, as follows:

[0117] Wavelength: 1030nm Repetition frequency: 200kHz Pulse width: 8ps Average output: 30W

[0118] In the sixth embodiment, during creep feed grinding, the bottom surface 48d is cleaned or repaired, or both cleaned and repaired, by a laser beam L emitted from a collector 52e3. Specifically, the binder of the grinding wheel 48, grinding chips, etc. are melted or vaporized, or energy is imparted to the abrasive grains of the grinding wheel 48.

[0119] This makes it possible to perform at least one of removing grinding debris, sharpening the grinding wheel 48, and correcting the shape of the grinding wheel 48 on the bottom surface 48d side. Therefore, poor condition of the bottom surface 48d can be resolved without reducing work efficiency in creep feed grinding.

[0120] The condenser 52e3 is disposed at one location directly below the grinding surface 48a outside the movement region B, but may be disposed at two or more locations directly below the grinding surface 48a. Also, the condenser 52e3 may be disposed at two or more locations on one or both sides located outside the movement region B in the Y-axis direction.

[0121] In particular, by arranging the light collectors 52e3 at two locations on either side of the center 48c of the outer diameter 48b, it is possible to ensure the degree of freedom of rotation of the spindle 40. Note that the first or second modified example described above may also be applied to the creep feed grinding device 62e.

[0122] In addition, the structures, methods, etc. according to the above-described embodiments can be appropriately modified without departing from the scope of the present invention. The chuck table 6 may be a rectangular plate rather than a disk. In the case of a rectangular plate, the holding surface 6a is a substantially flat rectangular surface.

[0123] Furthermore, the workpiece 11 held by suction on the holding surface 6a is not limited to a disk-shaped wafer. The workpiece 11 may be a rectangular strip substrate made of mold resin or the like. Creep feed grinding may be performed on each strip substrate in a frame unit in which multiple strip substrates are held by a frame ring via protective tape.

[0124] It is also possible to use a combination of two different types of bottom surface conditioning units 50, 50a, 50b, 50c, 50d, and 50e. For example, the bottom surface conditioning units 50 and 50c are combined.

[0125] In this case, the first nozzle 52 is disposed at one of two positions sandwiching the center 48c of the outer diameter 48b, and the dressing portion 52c1 is disposed at the other position. This allows the bottom surface 48d side to be cleaned or repaired, or both cleaned and repaired, by the high-pressure water 54 from the first nozzle 52 and the dressing portion 52c1.

[0126] In particular, the high-pressure water 54 is effective in removing grinding chips adhering to the grinding wheel 48, and the dressing of the grinding wheel 48 by the dressing portion 52c1 is effective in sharpening the grinding wheel 48 and correcting its shape.

[0127] Therefore, when viewed in the X-Y plane, the first nozzle 52 may be arranged at one location on the side where the grinding wheel 48 exits the workpiece 11, and the dressing portion 52c1 may be arranged at another location on the side where the grinding wheel 48 enters the workpiece 11.

[0128] Furthermore, the bottom surface conditioning units 50 and 50d may be combined to clean or repair the bottom surface 48d side using high-pressure water 54 from the first nozzle 52 and a brush 52d, or both cleaning and repairing may be performed.

[0129] Similarly, the bottom surface conditioning units 50 and 50e may be combined to clean or repair the bottom surface 48d side with high-pressure water 54 from the first nozzle 52 and the laser beam L, or both.

[0130] The combination is not limited to the two types mentioned above, and various other combinations are possible. It is also possible to use a combination of three or more different types of bottom surface condition adjustment units 50, 50a, 50b, 50c, 50d, and 50e. [Explanation of symbols]

[0131] 2, 2a, 2b, 62a, 62b, 62c, 62d, 62e: Creep feed grinding device 4: base, 4a: recess 6: chuck table, 6a: holding surface, 6b: outer diameter, 6c: center 8: frame body, 8a: recess, 8b: flow path, 10: porous plate, 12: X-axis direction moving plate 11: Workpiece, 11a: Front surface, 11b: Back surface, 11c: Saw mark 14: Nut portion, 16: Screw shaft, 18: Drive source, 20: X-axis direction movement mechanism (movement mechanism) 22: Support structure, 24: Grinding feed unit, 26: Guide rail, 28: Holding member 30: Nut portion, 32: Screw shaft, 34: Drive source 36: Grinding unit, 38: Spindle housing, 40: Spindle, 42: Mount 44: Grinding wheel, 46: Base, 46a: Lower surface (one surface), 48: Grinding stone 48a: grinding surface, 48b: outer diameter, 48c: center, 48d: bottom surface 50, 50a, 50b, 50c, 50d, 50e: Bottom condition adjustment unit 52: First nozzle (bottom condition adjustment mechanism), 54: High-pressure water, 56: High-pressure water supply source 52a: Second nozzle (bottom condition adjustment mechanism) 54a1: abrasive grains, 54a2: high-pressure water, 56a: abrasive grain-containing high-pressure water supply source 52b: third nozzle (bottom condition adjustment mechanism), 54b: two-fluid 54b1: Pure water, 54b2: Air, 56b: Two-fluid supply source 52c1: Dressing part (bottom surface condition adjustment mechanism), 52c2: Base member 52d: Brush (bottom condition adjustment mechanism), 52d1: Bristle material, 52d2: Cylinder 52e: laser beam irradiation unit, 52e1: laser oscillator, 52e2: mirror 52e3: Condenser (bottom condition adjustment mechanism), 52e4: Lens A1: Loading / unloading area, A2: Predetermined area, B: Moving area, L: Laser beam

Claims

1. 1. A creep feed grinding apparatus comprising: a chuck table having a holding surface for suction-holding the workpiece; a grinding unit having a spindle, a grinding wheel including an annular base and a plurality of grinding wheels arranged annularly on one side of the base, the grinding wheel being attached to a lower end side of the spindle, and the outer diameter of the trajectory of the plurality of grinding wheels when the spindle rotates being larger than the outer diameter of the chuck table; a moving mechanism that moves the chuck table and the grinding unit relatively along a first predetermined direction that is perpendicular to the longitudinal direction of the spindle; a bottom surface condition adjustment mechanism that is located outside a relative movement area of ​​the chuck table in a second predetermined direction orthogonal to the first predetermined direction in a plan view when the chuck table and the grinding unit are moved relatively along the first predetermined direction by the movement mechanism, and that adjusts the condition of the bottom surface of each grinding wheel that comes into contact with the workpiece during creep feed grinding by performing at least one of removing grinding chips, sharpening, and shape correction on the bottom surface; A creep feed grinding device comprising:

2. 2. The creep feed grinding device according to claim 1, wherein the bottom surface condition adjustment mechanism has a first nozzle, and when creep feed grinding is performed on the workpiece by the grinding unit, high-pressure water is sprayed from the first nozzle onto the bottom surface.

3. 2. The creep feed grinding device according to claim 1, wherein the bottom surface condition adjustment mechanism has a second nozzle, and when creep feed grinding is performed on the workpiece by the grinding unit, high-pressure water containing abrasive grains is sprayed from the second nozzle onto the bottom surface.

4. 2. The creep feed grinding device according to claim 1, wherein the bottom surface condition adjustment mechanism has a third nozzle that sprays a mixture of two fluids, water and air, onto the bottom surface when the grinding unit performs creep feed grinding on the workpiece.

5. 2. The creep feed grinding device according to claim 1, wherein the bottom surface condition adjustment mechanism has a dressing portion, and when creep feed grinding is performed on the workpiece by the grinding unit, the dressing portion is brought into contact with the bottom surface to perform at least one of removing grinding chips, dressing, and shape correction on the bottom surface of each grinding wheel.

6. 2. The creep feed grinding device according to claim 1, wherein the bottom surface condition adjustment mechanism has a brush, and when creep feed grinding is performed on the workpiece by the grinding unit, the brush is brought into contact with the bottom surface to remove grinding chips, sharpen, or correct the shape of the bottom surface of each grinding wheel.

7. 2. The creep feed grinding device according to claim 1, wherein the bottom surface condition adjustment mechanism has a condenser of a laser beam irradiation unit, and when creep feed grinding is performed on the workpiece by the grinding unit, a laser beam is irradiated from the condenser onto the bottom surface to perform at least one of removing grinding chips, dressing, and shape correction on the bottom surface of each grinding wheel.

8. A creep feed grinding device as described in any one of claims 1 to 7, characterized in that it further comprises an additional bottom surface condition adjustment mechanism arranged to sandwich the moving area between itself and the bottom surface condition adjustment mechanism in the second predetermined direction, and which adjusts the condition of the bottom surface by performing at least one of removing grinding chips, sharpening and shape correction on the bottom surface of each grinding wheel.

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