Processing equipment

Abstract

To provide a processing device that enables the economical use of dresser boards. [Solution] The control means 8 of the processing apparatus includes a size storage unit 8a that stores the length (L) of the dresser board in the X-axis direction, a depth of cut storage unit 8b that stores the depth of cut (t) of the cutting blade to the dresser board, an outer diameter storage unit 8c that stores the measured outer diameter of the cutting blade, a timing storage unit 8d that stores the timing at which the outer diameter of the cutting blade changes due to wear, an update unit 8e that measures the outer diameter of the cutting blade at the timing stored in the timing storage unit 8d and updates the outer diameter stored in the outer diameter storage unit 8c, and a calculation unit 8f that calculates the index amount (Xi) of the cutting blade in the X-axis direction. The calculation unit 8f calculates the depth of cut (ω) formed in the dresser board from the outer diameter (d) and depth of cut (t) of the cutting blade as ω = 2(dt - t 2 ) 1 / 2 The index quantity (Xi) is calculated as (ω) + (α).

Description

[Technical Field]

[0001] The present invention relates to a processing apparatus for shaping the outer peripheral end face of a cutting blade by dressing. [Background technology]

[0002] A wafer, on which multiple devices such as ICs and LSIs are divided by planned division lines and formed on its surface, is then ground on the back surface by a grinding machine to form the desired thickness. After that, it is divided into individual device chips by a dicing machine, laser processing machine, etc., and the divided device chips are used in electrical equipment such as mobile phones and personal computers.

[0003] Since a chamfer is formed on the outer edge of the wafer, when the back surface of the wafer is ground to thin it, the chamfer becomes a sharp knife edge. Therefore, operators must exercise extra caution when handling the wafer. Furthermore, when the chamfer becomes a sharp knife edge, cracks are more likely to form from the outer edge of the wafer inward, increasing the risk of device damage. To address this, the applicant has proposed a technique to remove the chamfer beforehand to prevent the formation of a knife edge during grinding (see, for example, Patent Document 1).

[0004] This technology involves holding the back surface of a wafer with a holding table to expose the front surface, positioning a cutting blade formed to a thickness sufficient to remove the chamfer (for example, about 3 mm) around the outer circumference of the wafer, and then rotating the cutting blade while rotating the holding table to form an L-shaped groove deeper than the finished thickness of the wafer, thereby removing the chamfer. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-211409 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the use of cutting blades causes wear on the outer edge surface, changing from a flat surface to a curved surface and resulting in a tapered shape. If a portion of the chamfered area is removed using such a cutting blade, the inner angle between the outer edge surface of the wafer and the remaining chamfered area will not be sharp, and there is a risk that a knife edge will be formed on the outer edge of the wafer when the back surface of the wafer is ground. Therefore, the outer edge surface of the cutting blade is dressed with a dresser board periodically or as needed to restore a flat surface.

[0007] Furthermore, when separating a package substrate called a QFN (Quad Flat Non-leaded package) into individual devices, the wiring boards stacked on the surface are cut for each individual device using a cutting blade. However, the outer edge of the cutting blade wears down, changing from a flat surface to a curved surface and tapering. Using such a cutting blade prevents the wiring board from being cut with a sharp inner angle, which can lead to burrs and short circuits. Therefore, the outer edge of the cutting blade is dressed with a dresser board periodically or as needed to restore a flat surface.

[0008] However, there is a problem in that the amount of indexing of the cutting blade relative to the dresser board varies from person to person, preventing the proper and economical use of the dresser board.

[0009] The object of the present invention is to provide a processing apparatus that enables the economical use of dresser boards. [Means for solving the problem]

[0010] According to the present invention, the following processing apparatus is provided that solves the above problems. That is, A processing apparatus for shaping the outer end face of a cutting blade by dressing, The system includes a holding means for holding a dresser board, a cutting means that rotatably supports a rotating shaft on which a cutting blade is mounted, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction perpendicular to the X-axis direction, a Z-axis moving means for moving the cutting means in the Z-axis direction perpendicular to both the X-axis and Y-axis directions, a measuring means for measuring the outer diameter (d) of the cutting blade, and a control means. The control means is, A size storage unit that stores the size of the dresser board, including the length (L) in the X-axis direction of the dresser board, A cutting depth storage unit that stores the amount (t) of cutting the cutting blade into the dresser board, An outer diameter storage unit that stores the outer diameter (d) of the cutting blade measured by the measuring means, A timing memory unit that stores the timing at which the tip of the cutting blade wears down and the outer diameter (d) of the cutting blade changes, An update unit that measures the outer diameter (d) of the cutting blade with the measuring means at the timing stored in the timing storage unit and updates the outer diameter (d) stored in the outer diameter storage unit, A calculation unit that calculates the index amount (Xi) of the cutting blade in the X-axis direction relative to the dresser board, The system includes a replacement instruction unit that, if the cumulative value of the index amount (Xi) exceeds the length (L) of the dresser board in the X-axis direction at the next index amount (Xi), instructs the replacement of the dresser board without performing the next index, The calculation unit calculates the width of the cut formed in the dresser board (ω) from the outer diameter (d) of the cutting blade and the amount of cut into the dresser board (t) as ω = 2(dt - t 2 ) 1 / 2 A processing device is provided that calculates the index amount (Xi) = (ω) + (α) using the formula provided.

[0011] The control means prefers that the initial positioning of the cutting blade relative to the dresser board is to position the center of the cutting blade at an index amount (Xi) / 2 from the starting point of the length (L) in the X-axis direction of the dresser board.

[0012] In the depth-of-cut storage unit, the depth of cut (t) is subdivided so as to gradually become deeper like t1, t2, t3,.... It is desirable that the control means operates the Z-axis moving means to change the cutting blade in accordance with the depth of cut subdivided in the Z-axis direction and finally set it as the depth of cut (t).

[0013] It may be provided with a workpiece holding table for holding a workpiece, and perform a machining process of machining the workpiece held on the workpiece holding table by the cutting means.

[0014] The workpiece is a circular semiconductor wafer, and in the machining process, the cutting means can remove a chamfer formed on the outer periphery of the semiconductor wafer.

[0015] It is preferable that the control means measures the outer diameter (d) of the cutting blade with the measuring means each time the dressing of the cutting blade is completed and performs the machining process.

[0016] The control means includes a wear amount calculation unit that calculates a wear amount based on a change in the outer diameter (d) of the cutting blade updated by the update unit, and it is desirable to instruct a new replacement of the cutting blade when the wear amount calculated by the wear amount calculation unit reaches a predetermined value.

Effect of the Invention

[0017] The machining apparatus of the present invention is a machining apparatus for forming the outer peripheral end surface of a cutting blade by dressing, including a holding means for holding a dresser board, a cutting means rotatably supporting a rotating shaft with a cutting blade mounted thereon, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction orthogonal to the X-axis direction, a Z-axis moving means for moving the cutting means in the Z-axis direction orthogonal to the X-axis direction and the Y-axis direction, a measuring means for measuring the outer diameter (d) of the cutting blade, and a control means. The control means is A size storage unit that stores the size of the dresser board, including the length (L) in the X-axis direction of the dresser board, A cutting depth storage unit that stores the amount (t) of cutting the cutting blade into the dresser board, An outer diameter storage unit that stores the outer diameter (d) of the cutting blade measured by the measuring means, A timing memory unit that stores the timing at which the tip of the cutting blade wears down and the outer diameter (d) of the cutting blade changes, An update unit that measures the outer diameter (d) of the cutting blade with the measuring means at the timing stored in the timing storage unit and updates the outer diameter (d) stored in the outer diameter storage unit, A calculation unit that calculates the index amount (Xi) of the cutting blade in the X-axis direction relative to the dresser board, The system includes a replacement instruction unit that, if the cumulative value of the index amount (Xi) exceeds the length (L) of the dresser board in the X-axis direction at the next index amount (Xi), instructs the replacement of the dresser board without performing the next index, The calculation unit calculates the width of the cut formed in the dresser board (ω) from the outer diameter (d) of the cutting blade and the amount of cut into the dresser board (t) as ω = 2(dt - t 2 ) 1 / 2 By calculating this and setting the index amount (Xi) = (ω) + (α), economical use of the dresser board becomes possible. [Brief explanation of the drawing]

[0018] [Figure 1] A perspective view of the processing apparatus according to the present invention. [Figure 2] A perspective view of the holding mechanism shown in Figure 1. [Figure 3] A perspective view of the cutting mechanism shown in Figure 1. [Figure 4] Figure 3 is a perspective view of the cutting mechanism with the blade cover disassembled. [Figure 5] (a) Perspective view of the cutting mechanism with the blade cover shown in Figure 3 removed, (b) Exploded perspective view of the cutting mechanism shown in (a). [Figure 6](a) Perspective view of the measuring device shown in Figure 2, (b) Front view of the measuring device shown in (a). [Figure 7] A block diagram of the control means shown in Figure 1. [Figure 8] A schematic diagram showing the calculation process. [Figure 9] A schematic diagram illustrating the indexing process. [Figure 10] Perspective view of a semiconductor wafer. [Figure 11] (a) Schematic diagram showing the processing steps, (b) Perspective view of a semiconductor wafer with the chamfered portion removed. [Figure 12] A perspective view showing the Y-axis positioning process. [Figure 13] A perspective view showing the dressing process. [Modes for carrying out the invention]

[0019] Hereinafter, preferred embodiments of the processing apparatus according to the present invention will be described with reference to the drawings.

[0020] (Processing equipment 2) As shown in Figure 1, the processing apparatus 2 includes a holding means 4 for holding a dresser board, a cutting means 6 that rotatably supports a rotating shaft on which a cutting blade is mounted, an X-axis moving means (not shown) for moving the holding means 4 in the X-axis direction, a Y-axis moving means (not shown) for moving the cutting means 6 in the Y-axis direction perpendicular to the X-axis direction, a Z-axis moving means (not shown) for moving the cutting means 6 in the Z-axis direction perpendicular to both the X-axis and Y-axis directions, a measuring means 7 for measuring the outer diameter of the cutting blade, and a control means 8 for controlling the operation of the processing apparatus 2. The X, Y, and Z axis directions are indicated by arrows X, Y, and Z in Figure 1, respectively. The XY plane defined by the X-axis and Y-axis directions is substantially horizontal.

[0021] (Holding means 4 of processing device 2) As shown in Figure 2, the holding means 4 includes a rectangular dresser board holding table 10. A suction groove 10a is formed on the upper surface of the dresser board holding table 10, and the suction groove 10a is connected to a suction means (not shown). The dresser board holding table 10 uses the suction means to generate suction force in the suction groove 10a, and holds the rectangular dresser board 12 placed on the upper surface of the dresser board holding table 10 by suction. The dresser board 12 can be formed by mixing abrasive grains such as white alundum or green carbon into a bonding material such as vitrified bond or resin bond. The dimensions of the dresser board 12 may be, for example, 75 mm in length in the X-axis direction, 125 mm in length in the Y-axis direction, and 1 mm in thickness.

[0022] The holding means 4 further includes an X-axis movable member 14 that is movable in the X-axis direction, a bracket 16 that connects the X-axis movable member 14 and the dresser board holding table 10, and a workpiece holding table 18 supported by the X-axis movable member 14. A disc-shaped suction chuck 20 is positioned at the upper end of the workpiece holding table 18. The suction chuck 20 is made of a porous material such as porous ceramics and is connected to a suction means (not shown). The workpiece holding table 18 generates a suction force on the upper surface of the suction chuck 20 using the suction means and holds a workpiece such as a semiconductor wafer placed on the upper surface of the workpiece holding table 18 by suction.

[0023] (Cutting means 6 of processing device 2) As shown in Figures 3 and 4, the cutting means 6 comprises a rotating shaft housing 22, a rotating shaft 24 rotatably supported by the rotating shaft housing 22, an annular cutting blade 26 fixed to the rotating shaft 24, and a motor (not shown) for rotating the rotating shaft 24.

[0024] A blade cover 28 is attached to the tip of the rotating shaft housing 22. The blade cover 28 has a fixed part 28a fixed to the tip of the rotating shaft housing 22, a first detachable part 28b detachably attached to the tip of the fixed part 28a via a screw 30, and a second detachable part 28c detachably attached to the upper part of the fixed part 28a via a screw 32. The fixed part 28a and the first detachable part 28b are equipped with cutting fluid nozzles 34 that supply cutting fluid to the cutting blade 26 and the workpiece.

[0025] Referring to Figures 5(a) and 5(b), an annular mounting flange 24a protruding radially outward is provided on the outer circumferential surface of the tip side of the rotating shaft 24. A male thread 24b is formed on the outer circumferential surface of the rotating shaft 24 further towards the tip than the mounting flange 24a. First, a cutting blade 26 is mounted on the tip of the rotating shaft 24, then an annular detachable flange 36 is mounted, and finally a nut 38 is fitted onto the male thread 24b of the rotating shaft 24. In this way, the cutting blade 26 is sandwiched from both sides in the Y-axis direction by the mounting flange 24a and the detachable flange 36 of the rotating shaft 24, and the cutting blade 26 is fixed to the tip of the rotating shaft 24. When the rotating shaft 24 is rotated by the motor with the Y-axis direction as its axis, the cutting blade 26 rotates together with the rotating shaft 24. The cutting blade 26 is formed by fixing abrasive grains such as diamond with a binder such as resin bond or metal bond. The thickness of the cutting blade 26 can be arbitrarily selected depending on the processing requirements, but in the case of removing a portion of the chamfered part of the wafer, a cutting blade 26 with a thickness of about 3 mm may be used.

[0026] (X-axis moving means of processing device 2) Although not shown in the diagram, the X-axis moving mechanism includes a ball screw connected to the X-axis movable member 14 of the holding mechanism 4 and extending in the X-axis direction, and a motor that rotates this ball screw. The X-axis moving mechanism converts the rotational motion of the motor into linear motion using the ball screw and transmits it to the X-axis movable member 14 of the holding mechanism 4, causing the X-axis movable member 14 to move in the X-axis direction. As a result, the dresser board holding table 10 and the workpiece holding table 18 move in the X-axis direction.

[0027] (Y-axis moving means of processing device 2) The Y-axis moving mechanism includes a ball screw connected to the rotating shaft housing 22 of the cutting mechanism 6 and extending in the Y-axis direction, and a motor that rotates this ball screw. The Y-axis moving mechanism converts the rotational motion of the motor into linear motion using the ball screw and transmits it to the rotating shaft housing 22, causing the rotating shaft housing 22 to move in the Y-axis direction. As a result, the cutting blade 26 moves in the Y-axis direction.

[0028] (Z-axis moving means of processing device 2) The Z-axis moving mechanism includes a ball screw connected to the rotating shaft housing 22 of the cutting mechanism 6 and extending in the Z-axis direction, and a motor that rotates this ball screw. The Z-axis moving mechanism converts the rotational motion of the motor into linear motion using the ball screw and transmits it to the rotating shaft housing 22, causing the rotating shaft housing 22 to move in the Z-axis direction. As a result, the cutting blade 26 moves in the Z-axis direction.

[0029] (Measuring means 7 of processing device 2) As shown in Figures 6(a) and 6(b), the measuring means 7 includes a light-emitting element 7a and a light-receiving element 7b arranged facing each other in the Y-axis direction. The light-emitting element 7a and the light-receiving element 7b are supported by a support member 7c. A groove 7d is formed on the upper part of the support member 7c, with the light-emitting element 7a positioned on one side of the groove 7d and the light-receiving element 7b positioned on the other side of the groove 7d. In the measuring means 7, when the rotating cutting blade 26 is lowered by the Z-axis moving means and the tip side of the cutting blade 26 is positioned between the light-emitting element 7a and the light-receiving element 7b, the tip of the cutting blade 26 is detected by the change in the amount of light received by the light-emitting element 7a and the light-receiving element 7b. The measuring means 7 then uses the tip height Z0 and the center height Z1 of the cutting blade 26 to determine the outer diameter (d) of the cutting blade 26 from the following equation 1. Equation 1 d=2(Z1-Z0)

[0030] (Control means 8 of the processing apparatus 2) The control means 8 consists of a computer having a processor and memory. As shown in Figure 7, the control means 8 includes a size storage unit 8a, a depth of cut storage unit 8b, an outer diameter storage unit 8c, a timing storage unit 8d, an update unit 8e, a calculation unit 8f, and a replacement instruction unit 8g. Furthermore, the control means 8 in this embodiment includes a wear amount calculation unit 8h.

[0031] (Size storage unit 8a of the control means 8) The size storage unit 8a stores the dimensions of the dresser board 12, including its length (L) in the X-axis direction. The size storage unit 8a may also store the length and thickness of the dresser board 12 in the Y-axis direction.

[0032] (Cut depth storage unit 8b of control means 8) The depth of cut storage unit 8b stores the depth of cut (t) to be made by the cutting blade 26 into the dresser board 12. In the depth of cut storage unit 8b, the depth of cut (t) may be subdivided so that it gradually gets deeper, such as t1, t2, t3, ... For example, the dressing of the cutting blade 26 can be divided into first, second, and third steps, and the depth of cut and the number of dressings in each step can be set as follows. Z-axis index amount, number of dressings First step: 0.015mm, 20 times Second step: 0.005mm, 20 times Third step: 0.002mm, 15 times In the above example, the cutting depths t1, t2, and t3 are: t1 = 0.015 × 20 = 0.3 mm t2 = t1 + 0.005 × 20 = 0.4 mm t3 = t1 + t2 + 0.002 × 15 = 0.43 mm This is the result.

[0033] (Outer diameter storage unit 8c of the control means 8) The outer diameter storage unit 8c stores the outer diameter (d) of the cutting blade 26 measured by the measuring means 7.

[0034] (Timing memory unit 8d of control means 8) The timing memory unit 8d stores the timing at which the tip of the cutting blade 26 wears down and the outer diameter (d) of the cutting blade 26 changes. The amount of wear at the tip of the cutting blade 26 increases as the amount of use of the cutting blade 26 (length of cutting applied to the workpiece) increases, and the outer diameter (d) of the cutting blade 26 gradually decreases with use, but the timing to be stored in the timing memory unit 8d can be any timing. For example, the timing to be stored in the timing memory unit 8d can be the timing at which the tip of the cutting blade 26 wears down and the outer diameter (d) of the cutting blade 26 changes, when the cumulative length of cutting applied to the workpiece using the cutting blade 26 reaches a predetermined value (for example, 10m).

[0035] (Update unit 8e of the control means 8) At the timing stored in the timing storage unit 8d, the update unit 8e measures the outer diameter (d) of the cutting blade 26 by the measuring means 7, and replaces and updates the outer diameter (d) stored in the outer diameter storage unit 8c.

[0036] (Calculation unit 8f of the control means 8) The calculation unit 8f calculates the index amount (Xi) in the X-axis direction of the dresser board 12 with respect to the cutting blade 26. First, the calculation unit 8f calculates the cut width (ω) formed on the dresser board 12 from the outer diameter (d) of the cutting blade 26 stored in the outer diameter storage unit 8c and the cut amount (t) with respect to the dresser board 12 stored in the cut amount storage unit 8b as ω = 2(dt - t 2 ) 1 / 2 As is clear from referring to FIG. 8, the relationship among the outer diameter (d) of the cutting blade 26, the cut amount (t) with respect to the dresser board 12, and the cut width (ω) formed on the dresser board 12 can be expressed as in the following formula 2 from the Pythagorean theorem. Formula 2 (d / 2) 2 = ((d / 2) - t) 2 + (ω / 2) 2 From the above formula 2, the cut width (ω) can be expressed as in the following formula 3. Formula 3 ω = 2(dt - t 2 ) 1 / 2

[0037] The calculation unit 8f uses the calculated cutting width (ω) to determine the index amount (Xi) of the cutting blade 26 in the X-axis direction relative to the dresser board 12 as (Xi) = (ω) + (α). However, (α) may also be 0. Specifically, if the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω), the calculation unit 8f sets (α) to 0 and the index amount (Xi) to (ω) (Xi = ω). On the other hand, if the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω) plus the remainder, as shown in Figure 9, the calculation unit 8f sets the index amount (Xi) to (ω) + (α) (α = remainder / number of indices). Note that in Figures 8 and 9, the center of the cutting blade 26 is indicated by the symbol c.

[0038] (Replacement instruction unit 8g of control means 8) The replacement instruction unit 8g instructs the replacement of the dresser board 12 with a new one without performing the next index if the cumulative value of the index amount (Xi) exceeds the length (L) of the dresser board 12 in the X-axis direction at the next index amount (Xi). In other words, when dressing the cutting blade 26, if the tip (lower end) of the cutting blade 26 extends outside the dresser board 12, the cutting blade 26 cannot be dressed, so the replacement instruction unit 8g instructs the replacement of the dresser board 12 with a new one. The instruction to replace the dresser board 12 with a new one may be, for example, displayed on a monitor (not shown), sounded as an alarm, or a lamp lit or flashed.

[0039] (Wear amount calculation unit 8h of control means 8) The wear amount calculation unit 8h calculates the amount of wear based on the change in the outer diameter (d) of the cutting blade 26 updated by the update unit 8e. The wear amount calculation unit 8h uses the outer diameter (d) stored in the outer diameter storage unit 8c immediately before the update and the updated outer diameter (d) to calculate the amount of wear of the cutting blade 26. The control means 8 then instructs the replacement of the cutting blade 26 with a new one when the amount of wear calculated by the wear amount calculation unit 8h reaches a predetermined value. Support for replacing the cutting blade 26 with a new one may be provided, for example, by displaying it on a monitor (not shown), sounding an alarm, or lighting or flashing a lamp.

[0040] As shown in Figure 1, the processing apparatus 2 further includes a vertically movable cassette stand 42 on which a cassette 40 containing multiple workpieces is placed, an loading / unloading means 46 for pulling out workpieces before cutting from the cassette 40 and transporting them to a temporary storage table 44, and for transporting workpieces after cutting that are positioned on the temporary storage table 44 into the cassette 40, a first transport means 48 for transporting the workpieces before cutting that have been transported from the cassette 40 to the temporary storage table 44 to the workpiece holding table 18, an imaging means 50 for imaging the workpieces held on the workpiece holding table 18, a cleaning means 52 for cleaning the workpieces after cutting, and a second transport means 54 for transporting the workpieces after cutting from the workpiece holding table 18 to the cleaning means 52.

[0041] (Semiconductor wafer 56) Figure 10 shows a circular semiconductor wafer 56 (hereinafter simply referred to as "wafer 56") that can be processed by the processing apparatus 2 described above. The wafer 56 is formed from a suitable semiconductor material such as silicon. On the surface 56a of the wafer 56, a device region 62 is formed, in which multiple devices 58 such as ICs and LSIs are demarcated by grid-like division lines 60. A chamfered portion 64 is formed on the outer periphery of the wafer 56, surrounding the device region 62. For convenience, the ring-shaped boundary 66 between the device region 62 and the chamfered portion 64 is shown by a dashed line, but in reality, there is no line indicating the boundary 66.

[0042] (Method for processing wafer 56) Next, a method for processing the wafer 56 using the processing apparatus 2 described above will be explained.

[0043] (holding process) When processing the wafer 56, first, the wafer 56 is transported from the cassette 40 to the workpiece holding table 18, and a holding process is performed in which the wafer 56 is held on the workpiece holding table 18. In the holding process, first, the wafer 56 before processing is transported from the cassette 40 to the temporary storage table 44 by the loading / unloading means 46. Next, the wafer 56 is transported from the temporary storage table 44 to the workpiece holding table 18, which is positioned at the transfer position (position shown in Figure 1), by the first transport means 48, and the wafer 56 is placed on the upper surface of the workpiece holding table 18. Next, a suction force is generated in the suction chuck 20 of the workpiece holding table 18, and the back surface 56b of the wafer 56 is held by the workpiece holding table 18.

[0044] (Processing process) After the holding process is performed, a machining process is carried out in which the wafer 56 (workpiece) held on the workpiece holding table 18 is machined by the cutting means 6. Here, we will describe the machining process of removing a portion of the chamfered portion 64 of the wafer 56.

[0045] In the machining process, the workpiece holding table 18 is moved below the imaging means 50, and the wafer 56 is imaged by the imaging means 50. Next, based on the image of the wafer 56 captured by the imaging means 50, the cutting blade 26 is positioned on the chamfered portion 64 of the wafer 56. Then, the cutting blade 26 is rotated at a predetermined rotational speed (for example, 20,000 rpm) in the direction indicated by arrow R1 in Figure 11(a). The tip of the cutting blade 26 is then driven into the chamfered portion 64 of the wafer 56 to a predetermined depth, and cutting fluid is supplied from the cutting fluid nozzle 34 to the part of the cutting blade 26 that is being driven into, while the workpiece holding table 18 is rotated at a predetermined rotational speed (for example, 1.0 mm / s) in the direction indicated by arrow R2. This allows a required amount of the chamfered portion 64 to be removed. In Figure 11(b), the portion from which the chamfered portion 64 has been removed is indicated by reference numeral 68. Furthermore, the length of the cutting process described here may be the circumference of the wafer 56.

[0046] (Washing process) After the machining process is completed, a cleaning process is performed to clean the processed wafer 56. In the cleaning process, first, the workpiece holding table 18 is moved from below the cutting means 6 to the transfer position (the position shown in Figure 1). Next, the wafer 56 is transported from the workpiece holding table 18 to the cleaning means 52 by a second transport means 54. Then, the wafer 56 is cleaned by the cleaning means 52.

[0047] (Cassette delivery process) After the cleaning process is performed, a cassette loading process is carried out in which the cleaned wafer 56 is loaded into the cassette 40. In the cassette loading process, the cleaned wafer 56 is transported from the cleaning means 52 to the temporary storage table 44 by the first transport means 48. Then, the wafer 56 is loaded from the temporary storage table 44 into the cassette 40 by the loading / unloading means 46.

[0048] (Method for dressing the cutting blade 26) Next, a method for dressing the outer end face of the cutting blade 26 using the processing apparatus 2 described above will be explained.

[0049] (Outer diameter measurement process) As the wafer 56 is processed repeatedly as described above, the timing stored in the timing memory unit 8d of the control means 8 is reached. At that point, an outer diameter measurement process is performed in which the outer diameter (d) of the cutting blade 26 is measured by the measuring means 7. The timing for performing the outer diameter measurement process is any timing stored in the timing memory unit 8d. For example, it may be the timing when the cumulative length of the cutting process performed on the workpiece using the cutting blade 26 reaches a predetermined value (for example, 10 m). After measuring the outer diameter (d), the update unit 8e of the control means 8 updates the outer diameter (d) stored in the outer diameter memory unit 8c by replacing it with the measured outer diameter (d).

[0050] After the update unit 8e updates the outer diameter (d) of the cutting blade 26, the wear amount calculation unit 8h of the control means 8 calculates the amount of wear of the cutting blade 26 based on the change in the outer diameter (d) of the cutting blade 26 updated by the update unit 8e. If the amount of wear is less than a predetermined value, the calculation process described below proceeds. If the amount of wear reaches a predetermined value, the control means 8 instructs the system to replace the cutting blade 26 with a new one.

[0051] (calculation process) After performing the outer diameter measurement process, the cutting width (ω) formed in the dresser board 12 is calculated from the outer diameter (d) of the cutting blade 26 and the cutting depth (t) of the dresser board 12 as ω = 2(dt - t 2 ) 1 / 2 The calculation process is performed by the calculation unit 8f of the control means 8. The outer diameter (d) of the cutting blade 26 is the outer diameter (d) after measurement stored in the outer diameter storage unit 8c. The depth of cut (t) to the dresser board 12 may be a value previously input to the control means 8 by the operator. For example, if the outer diameter (d) of the cutting blade 26 after measurement is 58 mm and the depth of cut (t) to the dresser board 12 is 0.43 mm, the depth of cut (ω) is, ω = 2 × (58 × 0.43 - 0.43) 2 ) 1 / 2 = 9.95mm This is the result.

[0052] Furthermore, in the calculation process, after calculating the cutting width (ω), the calculation unit 8f of the control means 8 sets the index amount (Xi) of the cutting blade 26 in the X-axis direction relative to the dresser board 12. If the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω), the calculation unit 8f sets (α) to 0 and the index amount (Xi) to (ω) (Xi=ω). On the other hand, if the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω) plus the remainder, the calculation unit 8f sets the index amount (Xi) to (ω)+(α) (α=remainder / number of indices).

[0053] (Y-axis positioning process) After the calculation process is performed, a Y-axis positioning process is carried out in which the outer peripheral end face of the cutting blade 26 is positioned in the Y-axis direction on one side of the dresser board 12 held by the holding means 4 that extends in the X-axis direction (see Figure 12). In the Y-axis positioning process, the control means 8 is configured to position the center c of the cutting blade 26 at an index amount (Xi) / 2 from the starting point of the length (L) of the dresser board 12 in the X-axis direction. Figure 8 shows the initial position of the cutting blade 26 relative to the dresser board 12 when α=0. Also, the dashed line in Figure 9 shows the initial position of the cutting blade 26 relative to the dresser board 12 when α≠0.

[0054] (Z-axis positioning process) After performing the Y-axis positioning process, a Z-axis positioning process is performed to position the tip of the cutting blade 26 at the cutting position in the Z-axis direction from the surface of the dresser board 12. In the Z-axis positioning process, first, the cutting blade 26 is rotated in the direction indicated by arrow R1 in Figure 12. Then, while supplying cutting fluid from the cutting fluid nozzle 34 to the part of the cutting blade 26 tip that will make the cut, the Z-axis moving mechanism is activated to make the tip of the cutting blade 26 cut into the surface of the dresser board 12 and position it at the cutting position in the Z-axis direction.

[0055] (Dressing process) After performing the Z-axis positioning process, as shown in Figure 13, the Y-axis moving means is activated to move the cutting blade 26 in the Y-axis direction from one side of the dresser board 12 extending in the X-axis direction to the other side of the dresser board 12 extending in the X-axis direction, thereby performing a dressing process to flatten the outer peripheral end face of the cutting blade 26. In Figure 13, the notched groove formed on the surface of the dresser board 12 as a result of the dressing process is indicated by reference numeral 70.

[0056] Such a dressing process can be performed multiple times in the same cutting groove 70. That is, the control means 8 may operate the Z-axis moving means to change the cutting blade 26 according to the subdivided cutting amounts in the Z-axis direction, and finally determine the cutting amount (t). For example, the dressing process can be divided into first, second, and third steps, and the index amount in the Z-axis direction and the number of dressings in each step can be set as follows. Z-axis index amount, number of dressings First step: 0.015mm, 20 times Second step: 0.005mm, 20 times Third step: 0.002mm, 15 times In the above example, the final depth of cut (t) in the Z-axis direction is: 0.015×20+0.005×20+0.002×15=0.43mm That is the case.

[0057] After the dressing process is performed, the wafer 56 is processed repeatedly, and when the timing stored in the timing memory unit 8d of the control means 8 is reached, the outer diameter measurement process is performed to measure the outer diameter (d) of the cutting blade 26. Next, the calculation process is performed to calculate the cut width (ω) formed in the dresser board 12 and the index amount (Xi) of the cutting blade 26 in the X-axis direction relative to the dresser board 12. Next, the Y-axis positioning process is performed. At this time, the cutting blade 26 is positioned at a location in the X-axis direction that is an index amount (Xi) away from the position where the previous dressing process was performed (see Figure 9). Note that the example in Figure 9 is an example where the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω) plus the remainder, and in this case the index amount (Xi) is (ω) + (α) (α = remainder / number of indices). Then, after the Z-axis positioning process is performed, the dressing process is performed to dress the outer peripheral end face of the cutting blade 26 into a flat surface.

[0058] As the wafer 56 is processed and the cutting blade 26 is dressed repeatedly, there will come a time when the cumulative value of the index amount (Xi) exceeds the length (L) of the dresser board 12 in the X-axis direction with the next index amount (Xi). When this happens, the replacement instruction unit 8g of the control means 8 instructs that the dresser board 12 be replaced with a new one without performing the next index.

[0059] As described above, in this embodiment, the cutting width (ω) formed in the dresser board 12 is calculated from the outer diameter (d) of the cutting blade 26 and the amount of cutting (t) into the dresser board 12 as ω = 2(dt - t 2 ) 1 / 2 The calculated (ω) is used as the basis to set the index amount (Xi) of the cutting blade 26 in the X-axis direction relative to the dresser board 12, thereby enabling economical use of the dresser board 12.

[0060] Furthermore, when dividing a package substrate called a QFN (Quad Flat Non-leaded package) into individual devices, the wiring boards stacked on the surface are cut for each individual device using a cutting blade. However, the outer edge of the cutting blade wears down, changing from a flat surface to a curved surface and becoming tapered. Using such a cutting blade prevents the package substrate from being cut with a sharp inner angle, which can lead to burrs and short circuits. However, in this embodiment, dressing is performed automatically with an appropriate and economical index amount (Xi), thus eliminating the problem of individual differences in the index amount of the cutting blade 26 relative to the dresser board 12 among operators, which prevents the proper and economical use of the dresser board 12.

[0061] In the above embodiment, the outer diameter (d) of the cutting blade 26 is not measured after the dressing process. However, the control means 8 may measure the outer diameter (d) of the cutting blade 26 with the measuring means 7 each time the dressing of the cutting blade 26 is completed and then perform the machining process. This allows the machining process to reflect the accurate outer diameter (d) of the cutting blade 26, thereby further improving machining accuracy. [Explanation of Symbols]

[0062] 2: Processing equipment 4: Holding means 6:Cutting means 7: Measurement means 7a: Light-emitting element 7b: Photodetector 7c: Support member 7d: Groove 8: Control means 8a: Size storage section 8b: Cut depth memory section 8c: Outer diameter memory section 8d: Timing memory unit 8e: Update section 8f: Calculation section 8g: Replacement instruction part 8h: Wear amount calculation section 12: Dresser board 24: Rotation axis 26: Cutting blade 56: Wafer d: Outer diameter of the cutting blade ω: Cut width t: Amount of cut Xi: Index amount

Claims

1. A processing apparatus for shaping the outer end face of a cutting blade by dressing, The system includes a holding means for holding a dresser board, a cutting means that rotatably supports a rotating shaft to which a cutting blade is attached, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction perpendicular to the X-axis direction, a Z-axis moving means for moving the cutting means in the Z-axis direction perpendicular to both the X-axis and Y-axis directions, a measuring means for measuring the outer diameter (d) of the cutting blade, and a control means. The control means is, A size storage unit that stores the size of the dresser board, including the length (L) in the X-axis direction of the dresser board, A cutting depth storage unit that stores the amount (t) of cutting the cutting blade into the dresser board, An outer diameter storage unit that stores the outer diameter (d) of the cutting blade measured by the measuring means, A timing memory unit that stores the timing at which the tip of the cutting blade wears down and the outer diameter (d) of the cutting blade changes, An update unit that measures the outer diameter (d) of the cutting blade with the measuring means at the timing stored in the timing storage unit and updates the outer diameter (d) stored in the outer diameter storage unit, A calculation unit that calculates the index amount (Xi) of the cutting blade in the X-axis direction relative to the dresser board, The system includes a replacement instruction unit that, if the cumulative value of the index amount (Xi) exceeds the length (L) of the dresser board in the X-axis direction at the next index amount (Xi), instructs the replacement of the dresser board without performing the next index, The calculation unit calculates the width of the cut formed in the dresser board (ω) from the outer diameter (d) of the cutting blade and the amount of cut into the dresser board (t) as ω = 2(dt - t ２ ) １／２ A processing device that calculates the index amount (Xi) = (ω) + (α).

2. The processing apparatus according to claim 1, wherein the control means positions the center of the cutting blade at an index amount (Xi) / 2 from the starting point of the length (L) in the X-axis direction of the dresser board for the initial positioning of the cutting blade with respect to the dresser board.

3. In the depth of cut storage unit, the depth of cut (t) is subdivided so that it gradually becomes deeper, such as t1, t2, t3, ... The machining apparatus according to claim 1, wherein the control means operates the Z-axis moving means to change the cutting blade according to the subdivided cutting amount in the Z-axis direction, and finally set the cutting amount (t).

4. The processing apparatus according to claim 1, comprising a workpiece holding table for holding a workpiece, and performing a processing step of processing the workpiece held on the workpiece holding table by the cutting means.

5. The workpiece is a circular semiconductor wafer. The processing apparatus according to claim 4, wherein the cutting means removes a chamfered portion formed on the outer circumference of a semiconductor wafer in the processing step.

6. The processing apparatus according to claim 4 or 5, wherein the control means measures the outer diameter (d) of the cutting blade with the measuring means each time the dressing of the cutting blade is completed and performs the processing step.

7. The processing apparatus according to claim 1, wherein the control means includes a wear amount calculation unit that calculates the amount of wear based on the change in the outer diameter (d) of the cutting blade updated in the update unit, and when the amount of wear calculated by the wear amount calculation unit reaches a predetermined value, the apparatus instructs the replacement of the cutting blade with a new one.

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