Chamfering device and chamfering method

Abstract

Provided is a chamfering device 100 for grinding a peripheral edge of a wafer into a predetermined shape, the chamfering device comprising: a grinding wheel 16 that rotates around a first axis and abuts its peripheral edge to the peripheral edge of the wafer to grind the peripheral edge of the wafer; a tool 2 that rotates around a second axis and abuts its peripheral edge to the peripheral edge of the grinding wheel to adjust the shape of the peripheral edge of the grinding wheel; and a control device 30 that adjusts a relative position between the tool and the grinding wheel so that a locus of movement of an abutting position between the peripheral edge of the tool and the peripheral edge of the grinding wheel is the same as the predetermined shape. This device provides a chamfered wafer having an excellent shape accuracy or surface quality.

Description

Chamfering device and chamfering method

[0001] The present disclosure relates to a chamfering device and a chamfering method.

[0002] Patent Document 1 describes a chamfering device that chamfers the end face of a plate-shaped workpiece using grooves in a grinding wheel.

[0003] JP 2018-167331 A

[0004] In conventional chamfering devices, chamfering is performed by transferring the shape of the grooves in the grinding wheel to the end face of the workpiece. The shape of the end face of the workpiece is adjusted indirectly via the shape of the grooves in the grinding wheel. This makes the process of changing the shape complicated. Furthermore, since the shapes of various grinding wheels and grooves are transferred multiple times, managing the shape accuracy is also complicated.

[0005] One solution to this problem is to replace the grinding wheel with a different groove shape, but this increases costs. Also, the groove shape of the spare grinding wheel may deviate from the specified shape (become misshapen) while not in use. In this case, it may be necessary to adjust the groove shape.

[0006] The present disclosure can solve at least one of the problems of the prior art. The present disclosure can provide a chamfering device that provides chamfered wafers with excellent shape accuracy or surface quality.

[0007] The first chamfering device of the present disclosure is a chamfering device that grinds the periphery of a wafer into a predetermined shape, and is equipped with a grinding wheel that rotates around a first axis and grinds the periphery by abutting it against the periphery of the wafer, a tool that rotates around a second axis and abuts the periphery against the periphery of the grinding wheel to shape the periphery of the grinding wheel, and a control device that adjusts the relative positions of the tool and the grinding wheel so that the trajectory of the movement of the abutment position between the periphery of the tool and the periphery of the grinding wheel is identical to the predetermined shape.

[0008] A second chamfering device of the present disclosure is the first chamfering device, wherein the grinding wheel has a groove along its periphery, and the shape of the groove is transferred to the periphery of the wafer, thereby chamfering the wafer.

[0009] A third chamfering device of the present disclosure is the second chamfering device, wherein the tool is a metal blade whose thickness is smaller than the width of the groove and whose periphery is formed with an abrasive grain layer.

[0010] A fourth chamfering device of the present disclosure is the first chamfering device, further comprising a swivel mechanism, the swivel mechanism being configured to be able to change the inclination of the second axis.

[0011] A fifth chamfering device of the present disclosure is the fourth chamfering device, wherein the control device controls the swivel mechanism to make the second axis parallel to the first axis and bring the tool into contact with the grinding wheel.

[0012] A sixth chamfering device of the present disclosure is the first chamfering device, wherein the control device adjusts the relative position based on at least the radial size of the tool.

[0013] The seventh chamfering device of the present disclosure is the fifth chamfering device, wherein the tool is a metal blade having an abrasive layer formed on its periphery, and the abrasive layer is formed by electroforming.

[0014] The eighth chamfering device of the present disclosure is a chamfering device in which, in a steady state, the second axis, the first axis, and the rotation axis of the wafer are arranged in this order on the same axis in a planar view.

[0015] The chamfering method disclosed herein includes rotating a tool around a second axis, bringing the periphery of the tool into contact with the periphery of a grinding wheel to shape the periphery of the grinding wheel, and bringing the periphery of the grinding wheel into contact with the periphery of a wafer to grind the periphery of the wafer into a predetermined shape, wherein the shape of the periphery of the grinding wheel is shaped by adjusting the relative positions of the tool and the grinding wheel so that the trajectory of movement of the contact position between the periphery of the tool and the periphery of the grinding wheel is identical to the predetermined shape.

[0016] The present disclosure may provide a chamfering apparatus that provides chamfered wafers with excellent shape accuracy or surface quality.

[0017] 1 is a hardware configuration diagram of an embodiment of a chamfering device; FIG. 2 is a front view of the main parts of a dresser unit, a grinding unit, and a holding unit; FIG. 3 is a plan view of the main parts of a dresser unit, a grinding unit, and a holding unit; FIG. 4 is a side view of the dresser unit; FIG. 5 is a flow diagram of a truing procedure by an embodiment of a chamfering device; FIG. 6 is an explanatory diagram of a movement trajectory of a processing position, which is a contact position between an end of a tool and a groove in a grinding wheel; FIG. 7 is a front view of the main parts of an embodiment of a chamfering device; FIG. 8 is an explanatory diagram of a processing method when the tool is not swiveled; FIG. 9 is a front view showing the main parts of a conventional chamfering device; FIG. 10 is an explanatory diagram of a conventional example of chamfering; FIG. 11 is an explanatory diagram of a conventional example of chamfering; FIG. 12 is an explanatory diagram of a conventional example of chamfering;

[0018] First, the procedure for grinding (chamfering) the edge (periphery) of a wafer using a conventional chamfering device will be described. Figure 9A is a front view showing the main components of a conventional chamfering device. The main components of the chamfering device 60 are composed of a wafer feed unit 60-1 and a grindstone rotation unit 60-2.

[0019] The wafer feed unit 60-1 includes a wafer table TB, a truer 52, a spindle 53, and the like. The wafer table TB holds the wafer W to be processed on its main surface. The truer 52 is attached to the bottom of the wafer table TB. The truer 52 is used to form or reshape (hereinafter also referred to as "reshaping, etc.") the groove 16A of the grinding wheel 16. In this specification, reshaping the grinding wheel 16 is also referred to as "truing." The grinding wheel 16 is used for finishing chamfering. The grinding wheel 16 is typically a resin-bonded grinding wheel. Resin-bonded refers to a grinding wheel whose abrasive grains are bonded with a resin. The grinding wheel 16 is also referred to as a precision grinding wheel. The wafer table TB and the truer 52 are both disk-shaped and attached concentrically to the spindle 53. The grinding wheel 16 has a diameter smaller than that of the wafer W.

[0020] The spindle 53 is equipped with a motor (not shown). The wafer table TB and the truer 52 rotate around an axis θC. In addition, the wafer feed unit 60-1 is equipped with a position adjustment mechanism (not shown). The position adjustment mechanism can move the wafer table TB and the truer 52 arbitrarily in the X, Y, and Z axis directions.

[0021] The grinding wheel rotation unit 60-2 includes a second grinding wheel 50 and a grinding wheel 16. The second grinding wheel 50 is used to grind the peripheral edge of the wafer W and to form or reshape the truer 52. The second grinding wheel 50 is attached to a spindle 51. The second grinding wheel 50 is rotated about an axis θA by a motor (not shown) provided on the spindle 51. The second grinding wheel 50 is provided with a groove 50B (for rough grinding of the peripheral edge) for rough grinding (rough grinding) the edge of the wafer W, and a groove 50A for shaping or reshaping the edge of the truer 52. Of these, the groove 50A is sometimes called a master groove. The reshaping of the truer 52 is sometimes called truer truing. A metal-bonded grinding wheel is often used as the second grinding wheel 50. A metal-bonded grinding wheel refers to a grinding wheel whose binder contains metal. The diameter of the second grinding wheel 50 is typically about 40 to 80 mm.

[0022] The grinding wheel 16 is attached to a spindle 17. The grinding wheel 16 rotates about an axis θB by a motor (not shown) provided on the spindle 17. The axis θB is tilted by approximately 6 to 10 degrees (deg) with respect to the axes θA and θC. Finishing the wafer W using such a grinding wheel 16 improves the surface quality of the edge of the wafer W and improves the accuracy of the shape of the resulting wafer W. Grinding using a precision grinding wheel with the axis θB, which is the rotation axis, tilted is sometimes called "helical grinding." A resin-bonded grinding wheel is often used as the grinding wheel 16. The diameter of the grinding wheel 16 is often approximately 50 mm, for example.

[0023] Next, a conventional example of chamfering the edge of a wafer W using a chamfering device 60 will be described. Figures 9B to 9E are explanatory diagrams of a conventional example of chamfering. Of these, Figure 9B is an explanatory diagram showing the process of true-truing. First, the shape of the edge of the truer 52 is adjusted. The second grinding wheel 50 and the truer 52 are moved closer to each other by a position adjustment mechanism while rotating. Specifically, the positions of the groove 50A and the truer 52 are adjusted so that they abut, and the edge of the truer 52 is adjusted to the desired shape (true-truing).

[0024] Next, the shape of the groove 16A of the grinding wheel 16 is adjusted. Figure 9C is an explanatory diagram showing the process of truing the grinding wheel 16. The truer 52 and the grinding wheel 16 are brought closer to each other by the position adjustment mechanism while rotating. Specifically, the positions of the groove 16A and the end 52A of the truer 52 are adjusted so that they come into contact with each other, and the groove 16A is adjusted to the desired shape (truing).

[0025] Next, the edge WA of the wafer W held on the main surface of the wafer table TB is ground by the grooves 50B of the second grinding wheel 50. Fig. 8D is an explanatory diagram showing grinding (rough grinding) by the grooves 50B.

[0026] Next, the edge WA of the wafer W is finish-ground using the grinding wheel 16. Fig. 9E is an explanatory diagram showing the grinding (precision grinding) using the groove 16A. The finish grinding is helical grinding with an inclined axis θB. This allows the shape of the edge WA of the wafer W to be more precisely adjusted, and also improves the quality of the surface.

[0027] This grinding method was excellent in that it allowed a single chamfering device to quickly and stably process (mass-produce) a large number of wafers W. However, there were problems when attempting to produce a large variety of wafers W with various edge WA shapes in small quantities.

[0028] The first problem is that there are many groove and edge shapes to be adjusted, making the process complicated. The finished shape of the edge WA of the wafer W is affected by the groove 50A (master groove), the edge 52A of the truer 52, and the groove 16A of the grinding wheel 16. In other words, to adjust the finished shape of the edge WA of the wafer W, it is necessary to directly adjust the shape of the groove 16A of the grinding wheel 16. However, this requires adjustment of the shape of the edge 52A of the truer 52, and further requires adjustment of the shape of the groove 50A (master groove).

[0029] As described above, in the conventional method, the shape of the groove 16A of the grinding wheel 16 is adjusted indirectly, and therefore the procedure for changing the shape is complicated. Furthermore, since the shapes of the grooves and various grinding wheels are transferred multiple times, the management of the shape accuracy is also complicated.

[0030] The next problem is that replacing the grinding wheel 16 takes time. Instead of adjusting the shape of the groove 16A each time the shape of the target end WA is changed, it is possible to replace the grinding wheel 16 with one with a different shape of the groove 16A. However, replacing the grinding wheel 16 increases the downtime of the chamfering device. Furthermore, preparing multiple grinding wheels 16 also increases costs. Furthermore, the shape of the groove 16A of a spare grinding wheel 16 for replacement may deviate from the specified shape (become misshapen) while not in use. In this case, it may ultimately be necessary to adjust the shape of the groove 16A.

[0031] The next problem is the difficulty of reshaping and the like associated with helical grinding. When performing helical grinding, the axis θB, which is the rotation axis of the grinding wheel 16, is inclined relative to the axis θC, which is the rotation axis of the truer 52. Therefore, during truing, the truer 52 may be deformed (twisted) by a force including a component in the Z-axis direction. In such cases, the intended shape of the groove 16A may not be obtained, and the shape and surface quality of the edge WA of the final wafer W may be insufficient.

[0032] The next problem is the material of the second grinding wheel 50. In order to adjust the shape of the end 52A of the truer 52, it is necessary to adjust the shape of the groove 50B. However, the second grinding wheel 50 is used for rough grinding and is often a metal-bonded grinding wheel. Metal-bonded grinding wheels are not suitable for reshaping, so the only way to change the shape of the groove 50B is to remake it. This was also a problem.

[0033] The present disclosure solves at least one of the problems of the prior art. FIG. 1 is a hardware configuration diagram of an embodiment of a chamfering device. The chamfering device 100 is composed of a dresser unit 1-1, a grinding unit 1-2, a holding unit 1-3, and a control device 30 for these units. FIG. 2 is a front view of the main parts of the dresser unit 1-1, the grinding unit 1-2, and the holding unit 1-3. FIG. 3 is a plan view of FIG. 2, and FIG. 4 is a side view of the dresser unit 1-1. Note that the size of components in each figure may be adjusted for explanation purposes. The size ratios of components in each figure are not limiting unless otherwise specified.

[0034] The holder 1-3 includes a wafer table TB and a spindle (not shown). The wafer table TB holds the wafer W to be processed on its main surface. The spindle is equipped with a motor and rotatably holds the wafer table TB. The wafer table TB rotates in the ω4 direction around an axis θ3 (it may also rotate in the opposite direction). The holder 1-3 preferably also includes a position adjustment mechanism, similar to the wafer feed unit 60-1 in the conventional example. The position adjustment mechanism can move the wafer table TB arbitrarily in the X, Y, and Z directions.

[0035] The grinding unit 1-2 includes a grinding wheel 16 and a spindle 17 that rotates and drives the grinding wheel 16. The grinding wheel 16 is a disk-shaped grinding wheel having a linear groove 16A along its periphery. The groove 16A is a linear depression provided on the periphery of the disk-shaped grinding wheel 16. The groove 16A, i.e., the periphery, is brought into contact with the periphery of the wafer W that is the target of chamfering, and the shape of the groove 16A is transferred to the edge WA of the wafer W. In this way, the periphery of the wafer W is chamfered.

[0036] The grinding wheel 16 may be, for example, a resin-bonded grinding wheel with a diameter of about 50 mm. The width of the groove 16A formed in the grinding wheel 16 is not particularly limited and may be selected appropriately depending on the shape of the edge WA of the wafer W to be ground, etc. As an example, the width of the groove 16A is preferably about 5 mm. The grinding wheel 16 may be a precision grinding wheel used for finishing the edge WA of the wafer W.

[0037] The abrasive grains contained in the grinding wheel 16 are preferably, for example, metal powders of Fe, Cr, Cu, etc., diamond abrasive grains, cubic boron nitride abrasive grains, or mixtures thereof. The bond (binding agent) is preferably, for example, phenol resin, epoxy resin, polyimide resin, polystyrene resin, polyethylene resin, etc.

[0038] The grinding wheel 16 rotates around the axis θ2 in the ω3 direction (it may rotate in the opposite direction). The axis θ2 is inclined at an angle φ with respect to the axis θ3 (and the axis θ1 described below). During chamfering, the axis θ2, which is the center of rotation of the grinding wheel 16, is inclined at an angle φ with respect to the axis θ3, which is the center of rotation of the wafer W, and the two (the peripheral edges) are brought into contact with each other. The grinding wheel 16 can perform helical grinding. Helical grinding tends to improve the shape accuracy or surface quality of the edge WA of the wafer W. In this specification, the axis θ2 is also referred to as the first axis.

[0039] The dresser section 1-1 is mainly composed of a tool 2 and a swivel mechanism SWVL.

[0040] The tool 2 is a tool for aligning the groove 16A of the grinding wheel 16 with high precision. Specifically, it is a thin, rotary metal blade with a diameter of about 50 mm. An abrasive layer containing abrasive grains and a binder can be formed on the periphery of this metal blade as a cutting edge. The abrasive grains are not particularly limited, but metal powders such as Fe, Cr, and Cu, diamond abrasive grains, cubic boron nitride abrasive grains, or mixtures thereof are preferred, and diamond abrasive grains are preferred.

[0041] The binder is not particularly limited, but preferably contains a so-called metal. Examples of usable metals include copper, tin, iron, cobalt, tungsten, nickel, chromium, silver, titanium, and mixtures and alloys thereof. The method for producing the abrasive layer is not particularly limited, but examples include a sintering method, an electrodeposition method in which abrasive grains are fixed to a base metal by metal plating, a brazing method in which abrasive grains are fixed to a base metal by metal brazing, and an electroforming method in which layers in which abrasive grains are fixed by metal plating, similar to the electrodeposition method, are multilayered to form an abrasive grain layer.

[0042] In particular, an abrasive layer manufactured by electroforming is preferable because it tends to maintain sharpness even when worn. Furthermore, as will be described in detail later, the chamfering device 100 can perform truing taking into account wear of the tool 2, so it is easy to obtain a synergistic effect with a metal blade having an abrasive layer obtained by electroforming.

[0043] As an example, the tool 2 is preferably a metal blade having a thickness of approximately 0.5 mm, with an abrasive layer formed on its periphery by electroforming, the abrasive layer including diamond abrasive grains. The thickness of the tool 2 is preferably smaller than the width of the groove 16A of the grinding wheel 16. Specifically, the thickness is preferably 1 / 15 to 1 / 5, and more preferably 1 / 12 to 1 / 8, of the width of the groove 16A of the grinding wheel 16. The tool 2 is removably attached to the dresser spindle 3. The tool 2 rotates in the ω1 direction around the axis θ1 by the dresser motor 4 (it may rotate in the reverse direction). In this specification, the axis θ1 is also referred to as the second axis.

[0044] The swivel mechanism SWVL is hardware for swivelly operating the tool 2. The swivel mechanism SWVL may include a dresser spindle 3 and a dresser motor 4 for rotating the tool 2 in the ω1 direction, and the following hardware for rotating the tool 2 in the ω2 direction.

[0045] The swivel mechanism SWVL may include a swivel plate 5, a base plate 6, and a shaft 7. The tool 2, dresser spindle 3, and dresser motor 4 are mounted on the swivel plate 5. Both ends of the swivel plate 5 are supported by the base plate 6 via the shaft 7. At least one end of the shaft 7 is hollow, allowing wiring for the dresser motor 4 and the like to pass through. The tool 2 is configured to be rotatable in the ω2 direction around the axis X1. The swivel mechanism SWVL causes the tool to rotate in the ω1 direction while tilting the end 2A in the ω2 direction (swivel operation). Instead of supporting the swivel plate 5 via the shaft 7 in the above configuration, a swivel hinge may be provided between the swivel plate 5 and the base plate 6.

[0046] The dresser unit 1-1 includes a first position adjustment mechanism (not shown). The first position adjustment mechanism adjusts the relative positions of the dresser unit 1-1 and the grinding unit 1-2. At least one of the dresser unit 1-1 and the grinding unit 1-2 includes a position adjustment mechanism. The first position adjustment mechanism allows the entire dresser unit 1-1 to move in the X-, Y-, and Z-axis directions. The rotation of the tool 2 in the ω1 and ω2 directions and the movement in the X, Y, and Z-axis directions are controlled by the control device 30. As described above, the axis θ2 is inclined at a predetermined angle φ relative to the axis θ1. However, by rotating in the ω2 direction, the end 2A of the tool 2 can be easily adjusted according to the inclination of the groove 16A. That is, as one embodiment, by inclining the axis θ1 by the angle φ to form the axis θ1', the rotation axis of the tool 2' can be inclined at the angle φ relative to the Y-axis, and the end 2A' can be abutted against the groove 16A. The inclination (angle φ) at this time is not particularly limited, but for typical helical grinding, it is preferably 6 to 10° (deg), and more preferably 8 to 10° (deg).

[0047] It should be noted that when machining the groove 16A using the tool 2, it is not necessary to always adjust the axis θ1' and the axis θ2 to be parallel. They may be adjusted as appropriate depending on the conditions of the reshaping, etc. This increases the precision of the groove 16A to be reshaped, etc., and can shorten the time required for machining.

[0048] 2 and 3, the dresser unit 1-1, grinding unit 1-2, and holding unit 1-3 of the chamfering apparatus 100 are arranged in this order. First, as can be seen from Fig. 3, the axis θ1 about which the tool 2 rotates, the axis θ2 about which the grinding wheel 16 rotates, and the axis θ3 about which the wafer W and wafer table TB rotate are aligned in this order on the same axis Y1. Furthermore, the axis θ1 faces the axis θ3 with the axis θ2 in between.

[0049] As mentioned above, the dresser unit 1-1 and the holder unit 1-3 can be moved in the X-, Y-, and Z-axis directions by the first position adjustment mechanism, so the above axes are not always aligned on the same axis. However, in the steady state of the chamfering device 100, aligning at least the axis θ1 and the axis θ2 on the same axis (axis Y1) allows for more efficient truing of the groove 16A. The same axis (the same location as the processing location of the wafer W, and its 180-degree opposite position) is where the truing operation is performed on a horizontal plane. Therefore, compared to other locations, this is more advantageous when the influence of the helical angle is taken into account.

[0050] Next, an example of a procedure for truing the grinding wheel 16 using the tool 2 will be described. FIG. 5 is a flow diagram of the truing procedure using the chamfering device 100. First, in step S101, the machining position by the dresser unit 1-1 is calculated based on the diameter of the groove 16A of the grinding wheel 16, its position on the X axis, its position on the Y axis, its position on the Z axis, and the diameter of the tool 2. The calculation of the machining position is performed by the control device 30. Specifically, the processor 31 executes instructions stored in the memory 32 to calculate the machining position.

[0051] The diameter of the groove 16A and the diameter of the tool 2 used in this process may be stored in advance in the memory 32. Alternatively, the radial size (diameter or radius) of the groove 16A and the radial size of the tool 2 may be actually measured using a measuring device (not shown) provided in the chamfering device 100, and the actual measured values ​​may be used. In particular, by actually measuring the radial size of the tool 2 and reflecting this in the calculation of the processing position, the shape accuracy of the wafer W after grinding is further improved.

[0052] By calculating the machining position using the actual measured values ​​of the groove 16A and the diameter (or radius) of the tool 2, the groove 16A can be reshaped more accurately. The tool 2 generally wears with each truing. As an example, the tool 2 has an abrasive grain layer formed by electroforming on its periphery. Therefore, even if it wears, the performance of the cutting edge is not likely to deteriorate, and in many cases, this does not pose a practical problem in machining. However, by calculating the machining position taking into account the degree of wear in the diameter direction of the tool 2, the shape accuracy can be further improved.

[0053] The position of the tool 2 can be freely moved by the first position adjustment mechanism, and the actual measured value of the diameter (or radius) of the tool 2 reflects the degree of wear in the diametric direction of the tool 2. Calculating the machining position using this value simply means calculating the machining position where the tool 2 cuts in the direction of the axis Y1 to account for the wear. Therefore, even if the tool 2 is worn, the groove 16A can be made closer to the desired shape with higher accuracy.

[0054] Next, in step S102, the position on the Z axis of the end 2A of the tool 2 is aligned with the position on the Z axis of the groove 16A of the grinding wheel 16, and the dresser part 1-1 is moved along the Y1 axis toward the grinding wheel 16 to cut into the grinding wheel 16. At this time, the axis θ1, which is the rotation axis of the tool 2, may be tilted so as to be parallel to the axis θ2, which is the rotation axis of the grinding wheel 16. The rotation axis of the tool 2 after tilting is the axis θ1', and for ease of explanation, the tool at this time will be referred to as tool 2' and the end as end 2'A (see FIG. 2).

[0055] Next, in step S103, the movement amount of the tool 2' in the X-axis and Y-axis directions is adjusted so that the movement trajectory of the processing position, which is the contact position between the end 2'A of the tool 2' and the groove 16A of the grinding wheel 16, is the same as the periphery (predetermined shape) of the wafer W after grinding, thereby reshaping the groove 16A. The periphery of the wafer W means the shape of the end WA of the wafer W after processing. Note that this adjustment of the movement amount is performed by the control device 30. Specifically, the processor 31 executes instructions stored in the memory 32 to adjust the movement amount.

[0056] FIG. 6 is an explanatory diagram of the movement trajectory of the processing position, which is the contact position between the end 2'A and the groove 16A. Processing positions PL1, PL2, and PL3 are contact positions between the tool 2' and the groove 16A. FIG. 6 shows that this contact position moves in the order of processing positions PL1, PL2, and PL3. At this time, the trajectory WT drawn by the processing positions PL1, PL2, and PL3 is identical to the periphery of the wafer W. The trajectory WT reflects the shape of the periphery of the wafer W after chamfering by the groove 16A. In other words, the trajectory WT coincides with the periphery of the final wafer W to which the shape of the groove 16A is transferred by contacting the wafer W with the groove 16A. By adjusting the movement trajectory of the processing position as described above, precise truing of the grinding wheel 16 can be performed using a tool 2 with a diameter smaller than that of the wafer W. This is because it is sufficient that the machining position is on the locus WT within the contact range FT between the groove 16A and the tool 2'. In other words, by making the locus WT of the machining position by the tool 2' coincide with the predetermined shape of the wafer W within the contact range FT, more precise truing of the groove 16A becomes possible using a tool 2 having a smaller diameter than the wafer W.

[0057] The chamfering method using the chamfering apparatus 100 differs significantly from that using conventional apparatuses in that it does not include a truing process. Conventionally, truing was necessary to manufacture wafers W with different shapes of edge WA using a single chamfering apparatus. The problems with this have already been explained. In contrast, the present method directly forms or reshapes the groove 16A while moving the tool 2 in the X-axis, Y-axis, and Z-axis directions. Even if the target shape of the edge WA is changed, the shape of the groove 16A in the grinding wheel 16 can be directly adjusted. This allows the wafer W to be chamfered more easily, more quickly, or with greater precision.

[0058] There is another difference: the dresser unit 1-1 is provided with a swivel mechanism SWVL, which improves the accuracy of truing.

[0059] When truing the grinding wheel 16 using conventional equipment, a load having a Z-axis component is likely to be applied to the truer 52, which can cause twisting of the truer 52. This twisting can result in insufficient accuracy in reshaping, etc. Considering suitability for truer truing, it was necessary to use a resin-bonded grinding wheel for the truer 52. This made it prone to insufficient rigidity and prone to twisting.

[0060] On the other hand, in the chamfering method using the chamfering device 100, the axis θ1, which is the axis of rotation, can be tilted to axis θ1' using the swivel mechanism SWVL. As a result, a load having a component in the direction of the axis of rotation is less likely to be applied to the tool 2. This can suppress the occurrence of twisting. This further increases the accuracy of the shape of the resulting groove 16A. This means that the accuracy of the shape of the edge WA of the resulting wafer W is also increased. Another advantage is that, as mentioned above, the tool 2 does not require reshaping such as through-truing, so a metal blade can be used. This further suppresses the occurrence of twisting.

[0061] Next, in step S104, the tool 2' is moved along the axis θ1', which is the rotation axis, and / or swiveled to reshape the entire groove 16A. FIG. 7 is a front view of the main parts of the chamfering apparatus 100 in this step. This step and step S103 can be performed simultaneously. That is, while moving the tool 2' along the axis θ1', the tool 2' is also moved in a plane perpendicular to the axis θ1' so that the machining position moves along the trajectory WT. At this time, the corresponding position in the thickness direction of the wafer W can be determined based on the amount of movement of the tool 2' along the axis θ1' and / or the angle of the swivel movement, and the trajectory WT can be changed.

[0062] The method for truing by tilting the tool 2 and setting the rotation axis as the axis θ1' has been described above. However, the truing method using the chamfering device 100 is not limited to the above. For example, if the axis θ2, which is the rotation axis of the grinding wheel 16, is parallel to the Z axis (not for helical grinding), the rotation axis can remain the axis θ1. In other words, tilting the axis θ2 is not essential.

[0063] Furthermore, even if the grinding wheel 16 is for helical grinding, the rotation axis may remain the axis θ1, or the axis θ1 and the axis θ1' may be used in combination.

[0064] FIG. 8 is an explanatory diagram of a machining method when the tool 2 is not swiveled. The grinding wheel 16 can be tilted 6 to 10 degrees with respect to the Z axis for helical grinding. In FIG. 7, the axis θ1, which is the rotation axis of the tool 2, is parallel to the Z axis. The control device 30 then moves the tool 2 or the grinding wheel 16 up and down in the Z axis direction to machine the grinding wheel 16. In this case, the shape of the end 2A of the tool 2 may be shaped to correspond to the groove 16A.

[0065] That is, the chamfering device 100 does not need to have the swivel mechanism SWVL in the dresser unit 1-1. In both of the processing methods shown in Figures 7 and 8, the movement trajectory WT of the processing position is controlled to coincide with the peripheral edge of the wafer W, thereby reshaping the groove 16A. In either case, the groove 16A can be reshaped directly without first reshaping the truer 52, making changing the shape of the groove 16A in the grinding wheel 16 easier and more efficient than conventional methods. When the chamfering device 100 is equipped with the swivel mechanism SWVL, the groove 16A can be reshaped without being affected by the inclination of the axis θ2, which is the rotation axis of the grinding wheel 16. This reduces factors that reduce accuracy, and further improves the final W-shape accuracy of the wafer W.

[0066] 100 Chamfering device 1-1 Dresser section 1-2 Grinding section 1-3 Holding section 2 Tool 3 Dresser spindle 4 Dresser motor 5 Swivel plate 6 Base plate 7 Shaft 16 Grinding wheel 30 Control device 31 Processor 32 Memory

Claims

1. A chamfering device for grinding the edge of a wafer into a predetermined shape, comprising: a grinding wheel that rotates around a first axis and grinds the edge by bringing it into contact with the edge of the wafer; a tool that rotates around a second axis and brings the edge into contact with the edge of the grinding wheel, shaping the edge of the grinding wheel; and a control device that adjusts the relative positions of the tool and the grinding wheel so that the trajectory of the contact position between the edge of the tool and the edge of the grinding wheel is the same as the predetermined shape.

2. The chamfering device according to claim 1, wherein the grinding wheel has a groove along its periphery, and the shape of the groove is transferred to the periphery of the wafer to chamfer the wafer.

3. The chamfering device according to claim 2, wherein the tool is a metal blade having a thickness smaller than the width of the groove and an abrasive grain layer formed on the periphery.

4. The chamfering device according to claim 1, further comprising a swivel mechanism, wherein the swivel mechanism is configured to be able to change the inclination of the second axis.

5. The chamfering device according to claim 4, wherein the control device controls the swivel mechanism to make the second axis parallel to the first axis and bring the tool into contact with the grinding wheel.

6. The chamfering device according to claim 1, wherein the control device adjusts the relative position based on at least the radial size of the tool.

7. The chamfering device according to claim 5, wherein the tool is a metal blade having an abrasive layer formed on its periphery, the abrasive layer being formed by electroforming.

8. The chamfering device according to claim 1, wherein in a steady state, the second axis, the first axis, and the rotation axis of the wafer are arranged in this order on the same axis in a plan view.

9. A chamfering method comprising: rotating a tool around a second axis, bringing the periphery of the tool into contact with the periphery of a grinding wheel, and shaping the periphery of the grinding wheel; and bringing the periphery of the grinding wheel into contact with the periphery of a wafer, and grinding the periphery of the wafer into a predetermined shape, wherein the shape of the periphery of the grinding wheel is shaped by adjusting the relative positions of the tool and the grinding wheel so that the trajectory of the movement of the contact position between the periphery of the tool and the periphery of the grinding wheel is the same as the predetermined shape.

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