Processing equipment and workpiece processing method

Abstract

To ensure reliable removal of processing debris, enable high-precision edge trimming, and extend the lifespan of the processing tool. [Solution] The processing apparatus 1 is a device for processing the outer circumference of the lower surface of a disc-shaped workpiece W into a ring shape, and comprises a table 10 that supports the workpiece W by injecting water (fluid) from a fluid injection port 11 that opens into a C-ring-shaped support surface 10a with a gap in part of the ring, a processing unit 20 equipped with a grinding wheel (processing tool) 21a that rotates with at least a part of it facing the gap in the support surface 10a, a lifting mechanism 30 that raises and lowers the grinding wheel 21a, and a rotation mechanism 40 that rotates the workpiece W around an axis perpendicular to the support surface 10a. The processing method for the workpiece W comprises a workpiece support step of supporting the workpiece W in a floating position, a workpiece rotation step of rotating the workpiece W by the rotation mechanism 40, and a processing step of processing the outer circumference of the lower surface of the workpiece W into a ring shape.

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing the outer peripheral portion of the lower surface of a workpiece into a ring shape and a workpiece processing method implemented using the processing apparatus.

Background Art

[0002] For example, semiconductor chips are used in various electronic devices. In order to meet the recent requirements for thinning and miniaturization of electronic devices, wafers are ground and finished thinner. Then, the wafers ground this thin are chamfered (R chamfered) on their outer peripheral edges to prevent cracking and dust generation during the manufacturing process. Therefore, when a wafer with a chamfered outer peripheral edge is ground thin, the chamfered portion on the outer periphery becomes a sharp knife edge shape, and there is a problem that chipping occurs from the outer periphery and the wafer is damaged.

[0003] Therefore, a cutting blade is cut into the chamfered portion on the outer periphery of the wafer to form a ring-shaped processing groove with a predetermined width and a predetermined depth by trimming (edge trimming), and then, by grinding the back surface of the wafer, the processing groove and the knife edge-shaped portion are removed simultaneously (see Patent Document 1). Also, when reducing the diameter of the wafer, after forming a ring-shaped processing groove by edge trimming on the outer peripheral portion of the wafer, the surface on the side opposite to the side where the processing groove of the wafer is formed is ground to remove the processing groove portion.

[0004] By the way, in edge trimming for forming a ring-shaped processing groove on the outer peripheral portion of a wafer, while rotating a table holding the wafer, a rotating cutting blade is brought into contact with the wafer to form a ring-shaped processing groove on the upper surface outer peripheral portion of the wafer. However, there is a possibility that processing defects or the like may occur due to uneven wear of the cutting blade.

[0005] Therefore, in Patent Documents 2 and 3, there are proposals to shape (truening or dressing) the cutting blade when the uneven wear of the cutting blade reaches a predetermined amount or more. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2010-245167 [Patent Document 2] Japanese Patent Publication No. 2013-146831 [Patent Document 3] Japanese Patent Publication No. 2015-076483 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in conventional cutting devices, including those proposed in Patent Documents 1 to 3, edge trimming is performed by contacting the outer periphery of the upper surface of the wafer from above with the cutting blade. As a result, the processing debris generated by trimming is not easily discharged from the wafer, and the debris accumulates on the upper surface of the wafer. Therefore, not only is it impossible to perform wafer edge trimming with high precision, but it also leads to a decrease in the lifespan of the processing tool, resulting in the problem of increased frequency of tool replacement.

[0008] The present invention has been made in view of the above problems, and its object is to provide a processing apparatus and a workpiece processing method that can reliably discharge processing chips and perform high-precision edge trimming, as well as extend the lifespan of the processing tool. [Means for solving the problem]

[0009] To achieve the above objective, the invention described in claim 1 is a processing apparatus for processing the outer periphery of the lower surface of a disc-shaped workpiece into a ring shape, comprising: a table having a C-ring-shaped support surface on its upper surface with a gap in part of the ring, and a fluid being injected from a fluid injection port opening into the support surface to support the workpiece in a floating position; a processing unit for processing the workpiece floating on the support surface, equipped with a processing tool that is positioned in a notch formed by cutting out a part of the outer periphery of the table that constitutes the support surface and rotates about an axis intersecting the support surface; a lifting mechanism for raising and lowering the processing tool; and a rotation mechanism for rotating the workpiece about an axis perpendicular to the support surface.

[0010] The invention described in claim 2 is characterized in that, in the invention described in claim 1, the rotating mechanism comprises a drive roller and a driven roller that contact the outer circumferential surface of the workpiece, a drive motor for rotating the drive roller, and a horizontal movement mechanism for horizontally moving at least one of the drive roller and the driven roller.

[0011] The invention described in claim 3 is characterized in that, in the invention described in claim 1, it comprises a pressing table for pressing the upper surface of the workpiece.

[0012] The invention described in claim 4 is characterized in that, in the invention described in claim 3, the pressing table is provided with a suction holding mechanism for suction holding the upper surface of the workpiece.

[0013] The invention described in claim 5 is a method for processing a workpiece, carried out using the processing apparatus described in any one of claims 1 to 4, characterized by comprising: a workpiece support step of ejecting a fluid from the fluid nozzle to float-support the workpiece on the support surface; a workpiece rotation step of rotating the workpiece by the rotation mechanism after the workpiece support step; and a processing step of bringing a rotating processing tool into contact with the lower surface of the rotating workpiece to process the outer circumference of the lower surface of the workpiece into a ring shape. [Effects of the Invention]

[0014] According to the workpiece processing method of the present invention, carried out using the processing apparatus of the present invention, the workpiece is supported by a fluid supplied between the table and the support surface and rotated by a rotation mechanism. The outer circumference of the lower surface is processed into a ring shape by the rotation of the processing tool, at least a portion of which faces the notch in the table. As a result, the processing chips generated by the processing of the workpiece fall by their own weight (free fall) and do not accumulate on the processed surface of the workpiece. Therefore, processing chips can be reliably discharged and high-precision edge trimming can be performed, and the lifespan of the processing tool can be extended, reducing the frequency of tool replacement. Furthermore, since the workpiece is supported by a fluid such as water ejected from the fluid injection port of the table, it can rotate smoothly without resistance to the table, and the amount of rotational drive of the workpiece can be kept small, thus reducing the power consumption of the drive motor. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view of the processing apparatus and workpiece according to the present invention (before the workpiece is held). [Figure 2] This is a cross-sectional side view of the processing apparatus and workpiece according to the present invention (before the workpiece is held). [Figure 3] This is a perspective view of the processing apparatus and workpiece according to the present invention (with the workpiece held). [Figure 4] This is a cross-sectional side view of a workpiece in a processing apparatus according to the present invention (with the workpiece being held). [Figure 5] (a) is a longitudinal cross-sectional view of the workpiece after edge trimming, and (b) is a longitudinal cross-sectional view of the workpiece after grinding. [Figure 6] This is a cross-sectional side view of a processing apparatus and workpiece according to another embodiment 1 of the present invention (with the workpiece being held). [Figure 7] (a) is a longitudinal cross-sectional view of the workpiece after edge trimming, and (b) is a longitudinal cross-sectional view of the workpiece after grinding. [Figure 8] This is a cross-sectional side view of a processing apparatus and workpiece according to another embodiment 2 of the present invention (with the workpiece being held). [Figure 9]The broken side view of the processing device and the workpiece according to Another Embodiment 3 of the present invention (in the state where the workpiece is held). [Figure 10] (a) is a broken partial side view showing a processing unit provided with an inclination adjustment mechanism, and (b) is an enlarged cross-sectional view taken along line A-A of (a).

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

[0017] [Configuration of Processing Device] First, the configuration of the processing device 1 according to the present invention will be described below based on FIGS. 1 and 2. The illustrated processing device 1 is a device for edge trimming the outer peripheral portion of the lower surface of a disk-shaped workpiece W. In the present embodiment, the processing device 1 is a device for edge trimming the outer peripheral portion of the lower surface of a disk-shaped wafer as the workpiece W to form a ring-shaped processing groove Wa (see FIG. 5(a)) in the outer peripheral portion of the lower surface.

[0018] The processing device 1 shown in FIGS. 1 and 2 includes a table 10 that floatingly supports the workpiece W on a C-ring-shaped support surface 10a having a gap in a part of the ring, and a processing unit 20 that is disposed in a notch portion 10A in which a part of the outer peripheral portion of the table 10 that at least partially constitutes the support surface 10a of the table 10 is cut out, and includes a cutting tool (grinding wheel) 21a that rotates about an axis (intersecting axis) perpendicular to the support surface 10a, a lifting mechanism 30 that raises and lowers the cutting tool (grinding wheel 21a) of the processing unit 20, and a rotating mechanism 40 that rotates the workpiece W about an axis perpendicular to the support surface 10a of the table 10 as main components. Here, the workpiece W is a thin disk-shaped member made of single crystal silicon or the like.

[0019] Next, each configuration of the table 10, the processing unit 20, the lifting mechanism 30, and the rotating mechanism 40, which are the main components of the processing device 1, will be described respectively.

[0020] (Table) The table 10 is constructed by forming a part of a cylindrical member, specifically a fan-shaped cutout 10A in plan view that passes through its center, so as to penetrate vertically. On the outer circumference of its upper surface, a horizontal support surface 10a in plan view is formed, which has a gap in part due to the cutout 10A. Multiple (eight in the illustrated example) circular fluid injection ports 11 are opened in at least three areas in the circumferential direction of the support surface 10a, specifically two at the ends near the gap and one midway between the two ends in the circumferential direction, for a total of three areas. As will be described later, fluid (water in this embodiment) is supplied from a fluid supply source 50 to each of the multiple fluid injection ports 11 opening in the support surface 10a of the table 10 via piping 51. Here, in this embodiment, the fluid supply source 50 is not installed in the processing apparatus 1, but it may be installed in the processing apparatus 1. The support surface 10a may be flush with the top surface, or it may be flush only in the three areas where the fluid outlets 11 are formed, with the other areas being lower and recessed.

[0021] (Processing unit) The processing unit 20 is a unit that forms a ring-shaped processing groove Wa (see Figure 5(a)) on the outer periphery of the lower surface of a workpiece W, which is floating-supported on the support surface 10a of the table 10, by processing (edge ​​trimming) the outer periphery of the lower surface of the workpiece W, as described later, and is positioned in the space formed by the notch 10A of the table 10. The processing unit 20 is positioned in the notch 10A so as to process the outer periphery of the lower surface of the workpiece W into a ring shape, but the notch 10A does not have to penetrate the top and bottom of the table 10, and only the upper part of the table 10 may be cut out.

[0022] Specifically, the processing unit 20 includes a grinding wheel 21 equipped with a ring-shaped grinding wheel 21a, which is a processing tool, and a processing tool motor 22 that rotates the grinding wheel 21 (grinding wheel 21a) around a vertical central axis. A disc-shaped mount 23 is attached to the upper end of an output shaft (motor shaft) 12a extending vertically upward from the processing tool motor 22, and the grinding wheel 21 is detachably attached to the upper surface of this mount 23. The grinding wheel 21 is composed of a ring-shaped or disc-shaped base 21b and a ring-shaped grinding wheel 21a, which is a processing tool, attached to the upper surface of the base 21b. Furthermore, the processing tool is not limited to the grinding wheel 21, but may also be a polishing pad or a cutting tool with a cutting tool placed on a base.

[0023] In this embodiment, the grinding wheel 21a is arranged such that at least a portion of it is housed within the space formed by the notch 10A of the table 10.

[0024] (Lifting mechanism) The lifting mechanism 30 is a mechanism that moves the grinding wheel 21a (grinding wheel 21) and the tool motor 22 of the processing unit 20 up and down as a single unit, and as shown in Figure 2, it is composed of a ball screw mechanism provided on a vertically erected column 31.

[0025] As shown in Figure 2, a recess 31a is formed in the center of the width direction of the inner surface of the column 31, and the end of the housing 22A is fitted and held in this recess 31a so as to be able to move up and down. The recess 31a extends in the vertical direction and functions as a guide rail for the vertical movement of the housing 22A. In addition, a drive motor 33 is positioned vertically on the upper surface of the column 31 via a bracket 32. The drive motor 33 is provided with an encoder 34 that detects the rotation direction and rotation speed of the drive motor 33, and the encoder 34 is electrically connected to a control unit (not shown).

[0026] Furthermore, the ball screw 35, which extends vertically downward from the drive motor 33, has its lower end rotatably supported on the column 31 via a bearing 36, and the end of the housing 22A is screwed onto the ball screw 35.

[0027] Therefore, when the drive motor 33 is started and the ball screw 35 is rotated forward and backward, the tool motor 22 and the grinding wheel 21a (grinding wheel 21), whose housing 22A is screwed onto the ball screw 35, move up and down together in the vertical direction.

[0028] (Rotation mechanism) The rotation mechanism 40, as described later, is a mechanism that rotates a workpiece W floating on the support surface 10a of the table 10 around a vertical axis passing through the center of the workpiece W, and comprises one drive roller 41 and two driven rollers 42 arranged along the upper outer circumference of the table 10. Here, the one drive roller 41 and the two driven rollers 42 are respectively positioned at locations where a plurality (8) of fluid outlets 11 are formed that open into the support surface 10a of the table 10.

[0029] Here, a horizontal movement mechanism 43 is attached to one location on the upper part of the outer circumferential surface of the table 10. A drive motor 44 that rotates a drive roller 41 is supported on the horizontal movement mechanism 43 so as to move horizontally (more precisely, horizontally radially toward the center of the table 10). The drive roller 41 is attached to the upper end of an output shaft (motor shaft) 44a (see Figure 2) that extends vertically upward from the drive motor 44. The drive roller 41 may be configured to rotate by transmitting the rotation of the drive motor 44 via an endless belt. The horizontal movement mechanism 43 may also move a driven roller 42.

[0030] Furthermore, support brackets 45 are attached to two locations on the upper part of the outer circumferential surface of the table 10 (two locations close to the notch 10A), and a driven roller 42 is supported on each support bracket 45 so as to be able to rotate freely by a vertical rotation axis 46 (see Figure 2). The heights of the drive roller 41 and the driven roller 42 are set so that when the workpiece W is floating on the support surface 10a of the table 10, as shown in Figures 3 and 4, these drive rollers 41 and driven rollers 42 contact the outer circumferential surface of the workpiece W.

[0031] [Workpiece machining method] Next, a method for processing a workpiece W according to the present invention, which is carried out using the processing apparatus 1 configured as described above, will be explained.

[0032] The present invention relates to a method for processing a workpiece W, which involves forming a ring-shaped processing groove Wa (see Figure 5(a)) on the outer circumference of the lower surface of the workpiece W by edge trimming, and in this method, 1) Workpiece support process: 2) Workpiece rotation process: 3) Processing process: Each of these steps will be carried out sequentially.

[0033] The following explains each step in detail.

[0034] 1) Workpiece support process: The workpiece support process is a process in which a disc-shaped workpiece W, which is the workpiece to be processed, is float-supported on the C-ring-shaped support surface 10a of the table 10. In this workpiece support process, as shown in Figures 1 and 2, the drive roller 41 of the rotating mechanism 40 is waiting at a predetermined distance radially away from the outer circumferential surface of the table 10.

[0035] Then, water is supplied from the fluid supply source 50 via piping 51 to the fluid nozzles 11 that open at three locations on the support surface 10a of the table 10, and while water is being sprayed from each fluid nozzle 11, the workpiece W is supported by a transport means (not shown) and transported upwards to the table 10, and as shown in Figures 3 and 4, the workpiece W is placed on the support surface 10a of the table 10. At this time, the workpiece W is floating-supported on the support surface 10a of the table 10 by the pressure (water pressure) of the water sprayed upwards from each fluid nozzle 11. At this time, the two driven rollers 42 of the rotating mechanism 40 are in contact with the outer circumferential surface of the workpiece W.

[0036] Subsequently, the horizontal movement mechanism 43 of the rotating mechanism 40 moves the drive motor 44 and drive roller 41 radially toward the center of the workpiece W, causing the drive roller 41 to come into contact with the outer circumferential surface of the workpiece W. Then, as shown in Figures 3 and 4, the outer circumferential surface of the workpiece W One drive roller 41 and two driven rollers 42 are in contact with the workpiece, and the workpiece is floating on the support surface 10a of the table 10 while being positioned (centered) by these drive rollers 41 and driven rollers 42.

[0037] 2) Workpiece rotation process: In the preceding workpiece support process, as shown in Figures 3 and 4, when the workpiece W is floatingly supported on the support surface 10a of the table 10, the drive motor 44 of the rotation mechanism 40 is activated and the drive roller 41 is driven to rotate around a vertical central axis at a predetermined speed. Then, the driving force of the drive motor 44 is transmitted to the workpiece W via the contact resistance (frictional resistance) between the drive roller 41 and the outer circumferential surface of the workpiece W, and the workpiece W is driven to rotate around a vertical central axis at a predetermined speed. At this time, since the workpiece W is floatingly supported by water ejected from the fluid injection port 11 of the table 10, it can rotate smoothly without resistance to the table 10, and the rotational driving force of the workpiece W can be kept small, thereby keeping the power consumption of the drive motor 44 small.

[0038] 3) Processing process: The machining process involves machining (edge ​​trimming) the outer periphery of the lower surface of the workpiece W using a rotating grinding wheel 21a of the machining unit 20, while the workpiece W is rotating at a predetermined speed around its central axis in the preceding workpiece rotation process.

[0039] In other words, in this machining process, as shown in Figures 3 and 4, the horizontal position of the grinding wheel 21a is set to a position where a predetermined machining width B (see Figure 5(a)) is secured on the outer periphery of the lower surface of the workpiece W. Before machining, the grinding wheel 21a is waiting at a position spaced downward from the outer periphery of the lower surface of the workpiece W (see Figure 2).

[0040] From the above state, the tool motor 22 is started to rotate the grinding wheel 21a (grinding wheel 21) around a vertical axis at a predetermined speed, while the lifting mechanism 30 raises the grinding wheel 21a (grinding wheel 21) together with the tool motor 22. Then, as shown in Figure 4, the rotating grinding wheel 21a comes into contact with the outer periphery of the lower surface of the workpiece W, and the outer periphery of the lower surface of the workpiece W is ground (edge ​​trimmed) by the grinding wheel 21a, forming a ring-shaped machining groove Wa with a width B and depth (grinding allowance) h as shown in Figure 5(a) on the outer periphery of the lower surface of the workpiece W. The grinding allowance of the outer periphery of the lower surface of the workpiece W by the grinding wheel 21a is calculated based on the rotation speed of the drive motor 33 by the encoder 34. That is, when a detection signal from the encoder 34 is transmitted to a control unit (not shown), the control unit calculates the amount of upward movement of the grinding wheel 21a, i.e., the grinding allowance of the workpiece W, based on the received detection signal.

[0041] After the work support process, work rotation process, and machining process described above, a ring-shaped machining groove Wa (see Figure 5(a)) with width B and depth h is formed on the outer circumference of the lower surface of the workpiece W. The workpiece W is then held on the chuck table of a grinding device (not shown) with the side of the workpiece W on which the machining groove Wa is formed (the lower surface in Figure 5(a)) facing downwards. The chuck table is rotated at a predetermined speed around a vertical central axis together with the workpiece W, while a rotating grinding wheel (not shown) is lowered. The grinding wheel then comes into contact with the upper surface of the workpiece W, and the upper surface of the workpiece W is ground by the amount of grinding allowance Δt shown in Figure 5(a).

[0042] Here, as shown in Fig. 5(a), if the thickness of the work W before grinding with a diameter of φD is t0, the grinding allowance Δt of the upper surface of the work W is Δt>t0 - h …(1) set. That is, the grinding allowance Δt is set to a value at which all of the portion of the work W excluding the machining groove Wa (the portion with a thickness of t0 - h) is removed by grinding. As a result, finally, a work W1 with a diameter of φd and a thickness of t = t0 - Δt < h as shown in Fig. 5(b) is obtained, and the work W is reduced in diameter from φD to φd (<φD).

[0043] As is clear from the above description, according to the method for machining the work W according to the present invention implemented using the machining apparatus 1 according to the present invention, the work W floatingly supported on the support surface 10a of the table 10 receives supply of water or air from the fluid supply source 50 between the table 10 and the support surface 10a, and at least a part of the outer peripheral portion of the lower surface of the work W is machined in a ring shape by the rotation of the grinding wheel 21a disposed in the notch 10A of the table 10. Therefore, the machining chips generated by machining the work W do not stay on the machined surface (lower surface) of the work W by falling due to their own weight. For this reason, it is possible to reliably discharge the machining chips and perform high-precision edge trimming, and at the same time, the durable life of the grinding wheel 21a can be extended and the replacement frequency of the grinding wheel 21a can be kept low.

[0044] In addition, since the work W is floatingly supported by water or air ejected from the fluid ejection port 11 of the table 10, it can rotate smoothly without resistance with respect to the table 10, and the effect that the driving power of the rotating mechanism 40 can be reduced and the power consumption of the drive motor 44 of the rotating mechanism 40 can be reduced can also be obtained.

[0045] Incidentally, the above description was about the machining (edge trimming) of the outer periphery of the work W without chamfering on the outer periphery. However, as shown in FIG. 6, the machining apparatus 1 can perform the same machining on a disk-shaped work W having an arc-shaped chamfer (R chamfer or C chamfer) R on the outer periphery. In FIG. 6, the same reference numerals are given to the same elements as those shown in FIGS. 1 to 4, and the repeated description thereof will be omitted below.

[0046] Regarding such a work W with a chamfer R on the outer periphery, the outer peripheral portion of the lower surface thereof is also ground by the grinding wheel 21a, and as shown in FIG. 7(a), a ring-shaped machining groove Wa with a width B and a depth h is formed on the outer peripheral portion of the lower surface of the work W.

[0047] Then, with the surface of the work W on which the machining groove Wa is formed (the lower surface in FIG. 7(a)) facing down, the work W is held on the chuck table of a grinding apparatus (not shown), and while rotating the chuck table together with the work W at a predetermined speed around the vertical central axis, a rotating grinding wheel (not shown) is lowered. Then, the grinding wheel contacts the upper surface of the work W, and the upper surface of the work W is ground by the grinding allowance Δt shown in FIG. 7(a).

[0048] Here, the grinding allowance Δt of the upper surface of the work W is, as shown in FIG. 7(a), when the thickness of the work W with a diameter of φD before grinding is t0, Δt>t0 - h …(1) is set. That is, the grinding allowance Δt is set to a value at which all of the portion of the work W excluding the machining groove Wa (the portion with a thickness of t0 - h) is removed by grinding. As a result, finally, a work W2 with a diameter of φd and a thickness of t = t0 - Δt < h shown in FIG. 7(b) is obtained.

[0049] As described above, by forming a ring-shaped machining groove Wa by edge trimming on the outer peripheral portion of the lower surface of the work W with a chamfer R on the outer periphery before grinding, and then grinding the upper surface of the work W by a predetermined amount Δt, it is possible to solve the problem that a sharp edge portion is formed on the outer periphery of the work W.

[0050] Figure 8 shows a processing apparatus 1' relating to another configuration. In this processing apparatus 1', a disc-shaped presser table 60 with a diameter equal to or greater than that of the workpiece W is placed on the upper surface of a disc-shaped workpiece W floating on the support surface 10a of the table 10, and the outer circumference of the lower surface of the workpiece W is processed into a ring shape. Here, the workpiece W and the presser table 60 are integrally rotated at a predetermined speed around their central axis by drive rollers 41 that contact their outer circumferences. The presser table 60 may be annular, and its outer diameter is equal to or greater than the outer diameter of the workpiece W. In other words, the drive rollers 41 and driven rollers 42 are brought into contact with the outer surface of the presser table 60, and the presser table 60 is rotated. Here, in Figure 8, the same elements as those shown in Figures 1 to 4 are denoted by the same reference numerals, and further explanation of them is omitted below.

[0051] Therefore, in the processing method performed using the processing apparatus 1' shown in Figure 8, a pressing table 60 is provided to hold the workpiece W, and the workpiece W, which is supported on the support surface 10a, is pressed against the support surface 10a by the weight of the pressing table 60 or by a lifting mechanism (not shown) that raises and lowers the pressing table 60, thereby maintaining a flat state. As a result, the outer circumference of the lower surface of the workpiece W is processed into a ring shape with high precision by the grinding wheel 21a. In addition, in the processing method performed using this processing apparatus 1', it is possible to reliably discharge processing chips and perform high-precision edge trimming, and the durability life of the grinding wheel 21a is extended, which reduces the frequency of replacement of the grinding wheel 21a.

[0052] Figure 9 shows yet another form of processing apparatus 1'', in which the illustrated processing apparatus 1'' includes a holding table 70 that holds the upper surface of the workpiece W by suction with a flat suction surface 70a parallel to the support surface 10a. The holding table 70 is equipped with a suction path 72 that connects the suction surface 70a to a suction source 71, and the suction source 71 and the suction path 72 constitute a suction holding mechanism. The holding table 70 holds the workpiece W by suction with the suction surface 70a connected to the suction source 71, and the holding table 70 and the workpiece W are rotated integrally by a drive roller 41 that contacts the outer circumference of the holding table 70. The suction surface 70a of the holding table 70 may have an opening at one end of a plurality of suction paths 72. The suction surface 70a of the holding table 70 may also be the exposed surface of a porous member to which the suction paths 72 are connected. Furthermore, the holding table 70 may be configured such that the surface (bottom surface) on which the pressing table 60 presses the workpiece W is the suction surface 70a. In Figure 9, the same reference numerals are used for elements that are the same as those shown in Figures 1 to 4, and further explanations of these elements will be omitted below.

[0053] Therefore, in the processing method performed using the processing apparatus 1'' shown in Figure 9, the workpiece W is held by suction from a suction surface 70a connected to a suction source 71 of the holding table 70, and rotates integrally with the holding table 70, so that the outer circumference of the lower surface of the workpiece W is processed into a ring shape with high precision by the grinding wheel 21a. In addition, in the processing method performed using this processing apparatus 1'', the same effects can be obtained as well, such as reliable discharge of processing chips and high-precision edge trimming, and the durability life of the grinding wheel 21a is extended and the frequency of replacement of the grinding wheel 21a is kept low.

[0054] Incidentally, the processing apparatus 1,1',1'' described above may be equipped with a tilt adjustment mechanism 80 as shown in Figure 10(a). This tilt adjustment mechanism 80 adjusts the tilt of the output shaft 22a (grinding surface of the grinding wheel 21a) of the tool motor 22, and as shown in Figure 10(b), it is equipped with two lifting shafts 81 and one pivot shaft 82 that are vertically arranged at equal angular pitches (120° pitch) at three locations in the circumferential direction on a circle centered on the axis of the output shaft 22a. In other words, the tool motor 22 is tiltably supported at three points on the housing 22A by the two lifting shafts 81 and one pivot shaft 82. Note that the arrangement of the lifting shafts 81 and pivot shaft 82 is not limited to equal angular pitches.

[0055] Therefore, by raising and lowering the two lifting shafts 81 of the tilt adjustment mechanism 80, the workpiece motor 22 tilts relative to the horizontal plane around the pivot shaft 82, thereby adjusting the tilt of the output shaft 22a of the workpiece motor 22 (the grinding surface of the grinding wheel 21a attached to the output shaft 22a). The two lifting shafts 81 are, for example, of the screw type, consisting of a screw shaft and a nut, and the amount to which the screw shaft is screwed into the nut can be used to tilt the output shaft 22a. The lifting shafts 81 may also be of the piezoelectric type, and the output shaft 22a can be tilted by the magnitude of the voltage supplied to the piezoelectric element.

[0056] Furthermore, the processing apparatus 1,1',1'' may be equipped with a height measuring device that measures the height of the grinding surface of the workpiece W from the underside of the workpiece W. The height measuring device may be provided in the notch 10a and may be equipped with a moving mechanism that moves it in the radial direction of the support surface 10a in a direction parallel to the support surface 10a. The control unit then controls the tilt adjustment mechanism 80 based on the measurement value taken by the height measuring device. For example, if there is a difference between the height of the inner circumference side of the ring-shaped grinding surface and the height of the outer circumference side of the grinding surface, the lifting shaft 81 is operated to adjust the tilt of the grinding wheel 21a, which is the processing tool. Height measurement may also be taken at the midpoint between the inner and outer circumferences in the radial direction of the grinding surface. The control unit may control the tilt adjustment mechanism 80 based on the measurement values ​​at the three locations.

[0057] Furthermore, although not shown in the figures, the processing apparatus 1,1',1'' may be equipped with a dresser for periodically dressing the grinding surface of the grinding wheel 21a. By providing such a dresser and periodically dressing the grinding surface of the grinding wheel 21a, the outer circumference of the lower surface of the workpiece W can be stably processed in a ring shape by the grinding wheel 21a.

[0058] In the embodiments described above, a wafer was used as an example to explain the processing apparatus and processing method, but the present invention is equally applicable to processing apparatus and processing methods for any workpiece other than a wafer. That is, the workpiece W may be ring-shaped, or it may have a ring-shaped protrusion on the outer circumference of the lower surface of the workpiece W that forms the grinding surface, and a plurality of recesses or circular recesses in the central part other than the grinding surface. Furthermore, the workpiece W may be made of metal or resin.

[0059] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the technical idea described in the claims, specification, and drawings. [Explanation of Symbols]

[0060] 1, 1',1”: Processing device, 10: Table, 10A: Notch, 10a: Support surface, 11: Fluid injection nozzle, 20: Machining unit, 21: Grinding wheel, 21a: Grinding wheel, 21b: Base, 22: Tool motor, 22A: Housing, 22a: Output shaft (motor shaft) 23: Mount, 30: Lifting mechanism, 31: Column, 31a: Recess of column, 32: Bracket, 33: Drive motor, 34: Encoder, 35: Ball screw, 36: Bearing, 40: Rotating mechanism, 41: Driven roller, 42: Driven roller 43: Horizontal movement mechanism, 44: Drive motor, 44a: Output shaft (motor shaft), 45: Support bracket, 46: Rotating shaft, 50: Fluid supply source, 51: Piping, 60: Pressing table, 70: Holding table, 70a: Suction surface, 71: Suction source, 72: Suction path, 80: Tilt adjustment mechanism, 81: Lifting axis, 82: Pivot axis, R: R chamfer, W, W1, W2: workpiece, Wa: machined groove

Claims

1. A processing device for shaping the outer circumference of the lower surface of a disc-shaped workpiece into a ring shape, A table that provides floating support for a workpiece by injecting fluid from a fluid injection port opening in the support surface, which has a C-ring-shaped support surface on its upper surface with a gap in part of the ring, A processing unit for processing a workpiece floating on the support surface, comprising a processing tool positioned in a notch where a part of the outer circumference of the table constituting the support surface is cut out, and which rotates about an axis intersecting the support surface, A lifting mechanism for raising and lowering the aforementioned workpiece, A rotation mechanism for rotating the workpiece about an axis perpendicular to the support surface, A processing apparatus characterized by being equipped with the following features.

2. The aforementioned rotating mechanism is A drive roller and a driven roller that contact the outer circumferential surface of the workpiece, A drive motor that rotates the drive roller, A horizontal movement mechanism for moving at least one of the drive roller and the driven roller horizontally, The processing apparatus according to claim 1, characterized by comprising:

3. The processing apparatus according to claim 1, characterized in that it comprises a pressing table for pressing the upper surface of the workpiece.

4. The processing apparatus according to claim 3, characterized in that the pressing table is provided with a suction holding mechanism for suction holding the upper surface of the workpiece.

5. A method for processing a workpiece, carried out using a processing apparatus according to any one of claims 1 to 4, A workpiece support step in which a fluid is ejected from the fluid nozzle to support the workpiece in a floating manner on the support surface, After the workpiece support step, a workpiece rotation step is performed in which the workpiece is rotated by the rotation mechanism, A machining process in which a rotating machining tool is brought into contact with the lower surface of the rotating workpiece to machine the outer circumference of the lower surface of the workpiece into a ring shape, A method for processing a workpiece, characterized by performing the following.

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