Dicing device

Abstract

To provide a dicing device that can accurately detect elastic waves generated from a blade. [Solution] The dicing apparatus 1 comprises a processing table 22, a spindle 24, a blade 26, an elastic wave detection unit 90 for detecting elastic waves generated from the blade 26, a contact detection unit 114 for detecting contact between the blade 26 and the processing table 22, and a reference position setting unit 116 for setting a reference position for the blade 26. The elastic wave detection unit 90 comprises an AE sensor 92, a transmitting coil 94, and a receiving coil 94. A signal output from the AE sensor 92 is transmitted to the receiving coil 96 via the transmitting coil 94. The reference position setting unit 116 moves the spindle 24 and the processing table 22 relative to each other along the Z direction from a position where the blade 16 and the processing table 22 are separated, and sets the position where contact is detected by the contact detection unit 114 as the reference position for the blade 26.

Description

Technical Field

[0001] The present invention relates to a dicing device, and particularly to a dicing device that cuts a workpiece with a rotating blade or forms a groove in the workpiece.

Background Art

[0002] In a dicing device (so-called blade dicing machine) that cuts a workpiece with a blade (ultra-thin outer peripheral blade) attached to the tip of a spindle rotating at high speed or forms a groove in the workpiece, if an abnormality such as clogging occurs in the blade, processing defects (for example, chipping, etc.) will occur in the workpiece.

[0003] Patent Document 1 describes a device in which an AE sensor is attached to a fixed worktable. The device described in Patent Document 1 detects an elastic wave generated when cutting a workpiece with a blade by the AE sensor and measures the sharpness of the blade from the sensor output.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Elastic waves propagate in a substance but have the characteristic of greatly attenuating between non-uniform objects. Therefore, when the worktable rotates, depending on the position where the AE sensor is attached, there is a possibility that the elastic wave will be greatly attenuated at the intermediate bearing part or the like and accurate detection cannot be performed.

[0006] The present invention has been made in view of such circumstances, and an object thereof is to provide a dicing device capable of accurately detecting an elastic wave generated from a blade.

Means for Solving the Problems

[0007] To solve the above problems, the dicing apparatus according to the present invention comprises a table for holding a workpiece, a spindle that moves relative to the table, a blade mounting part integrally attached to the spindle, a blade mounted on the blade mounting part, and an elastic wave detection unit for detecting elastic waves. The elastic wave detection unit comprises an AE sensor attached to at least one of the spindle, the blade mounting part, and the table, a transmitting coil attached to at least one of the spindle, the blade mounting part, and the table and connected to the AE sensor, and a receiving coil positioned opposite the transmitting coil and magnetically coupled to the transmitting coil. The signal output from the AE sensor is transmitted to the receiving coil via the transmitting coil by mutual induction between the transmitting coil and the receiving coil.

[0008] In one embodiment of the present invention, the table, spindle, and blade mounting section are preferably rotating bodies. One embodiment of the present invention comprises a contact detection unit that detects contact between a blade and a table based on a signal output from an elastic wave detection unit, and a reference position setting unit that sets a reference position for the blade. Preferably, the reference position setting unit moves the spindle toward the table from a position where the blade and the table are separated, and sets the position where contact is detected by the contact detection unit as the reference position for the blade.

[0009] In one embodiment of the present invention, it is preferable to further include an estimation unit that estimates the state of the blade and / or the workpiece based on a signal output from an elastic wave detection unit during workpiece processing.

[0010] In one embodiment of the present invention, it is preferable that the estimation unit estimates the occurrence of chipping based on the signal output from the elastic wave detection unit.

[0011] In one embodiment of the present invention, it is preferable that the estimation unit estimates the state of blade clogging based on the signal output from the elastic wave detection unit.

[0012] In one embodiment of the present invention, it is preferable that the estimation unit estimates the state of the blade and / or workpiece by comparing it with a signal output from the elastic wave detection unit during stable cutting.

[0013] In one embodiment of the present invention, it is preferable that the AE sensor and the transmitting coil are attached to the blade mounting portion.

[0014] In one embodiment of the present invention, it is preferable that the AE sensor and the transmitting coil are mounted on the spindle.

[0015] In one embodiment of the present invention, it is preferable that the blade mounting portion is provided at the tip of the spindle, the AE sensor is built into the tip of the spindle, and the transmitting coil is attached to the base end of the spindle.

[0016] In one embodiment of the present invention, it is preferable that the AE sensor and the transmitting coil are mounted on a table.

[0017] In one embodiment of the present invention, it is preferable that the receiving coil and the transmitting coil are wound around at least one axis of rotation of the spindle, blade mounting section, and table.

[0018] In one embodiment of the present invention, it is preferable that a balance weight is provided in at least one of the spindle, the blade mounting section, and the table. [Effects of the Invention]

[0019] According to the present invention, elastic waves generated from a blade can be detected with high accuracy. [Brief explanation of the drawing]

[0020] [Figure 1] Figure 1 is a perspective view showing the schematic configuration of a dicing apparatus. [Figure 2] Figure 2 is a perspective view showing the schematic configuration of the machining section. [Figure 3] Figure 3 is a cross-sectional view showing the configuration of the blade mounting section. [Figure 4] Figure 4 is a rear view of the rear flange. [Figure 5] Figure 5 is a front view of the tip cover. [Figure 6] Figure 6 is a block diagram of the main functions of the system controller with respect to the cutter set. [Figure 7] Figure 7 is a graph showing an example of the output of the AE sensor. [Figure 8] Figure 8 is a flowchart showing the processing procedure of the cutter set. [Figure 9] Figure 9 is a diagram showing an example of the attachment structure of the AE sensor to the spindle. [Figure 10] Figure 10 is a diagram showing an example of the attachment structure of the AE sensor to the machining table. [Figure 11] Figure 11 is a bottom view of the sensor base. [Figure 12] Figure 12 is a top view of the coil base. [Figure 13] Figure 13 is a schematic view of the cutting line seen from above. [Figure 14] Figure 14 is a schematic view of the occurrence of chipping. [Figure 15] Figure 15 is a graph showing an example of the output of the AE sensor during machining. [Figure 16] Figure 16 is a graph showing an example of the output of the AE sensor during machining. [Figure 17] Figure 17 is a schematic view of the blade during machining. [Figure 18] Figure 18 is a graph showing an example of the output of the AE sensor during machining. [Figure 19] Figure 19 is a block diagram of the functions of the system controller with respect to estimation.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] (First Embodiment)

[0023] [Overall configuration of the dicing device] Figure 1 is a perspective view showing the schematic configuration of a dicing apparatus. Figure 1 shows the X, Y, and Z directions. The X and Y directions intersect each other. For example, the X and Y directions are orthogonal to each other. The Z direction intersects the X and Y directions. For example, the Z direction is orthogonal to the X and Y directions. Hereafter, the lengths in the X and Y directions may be referred to as thickness or width. The lengths in the Z direction may be referred to as thickness, depth, and height. In the Z direction, the direction toward the tip of the Z direction arrow may be referred to as upward, upper side, or up, and the direction opposite to the upward direction may be referred to as downward, lower side, or down. Hereafter, the axis parallel to the X direction may be referred to as the X-axis, the axis parallel to the Y direction may be referred to as the Y-axis, and the axis parallel to the Z direction may be referred to as the Z-axis. The plane containing the X and Y axes may be referred to as the horizontal plane.

[0024] The dicing apparatus 10 in this embodiment is a so-called blade dicer. The blade dicer cuts or cuts grooves into a workpiece W using a blade attached to the tip of a high-speed rotating spindle. The workpiece W is, for example, a semiconductor wafer.

[0025] As shown in Figure 1, the dicing apparatus 10 of this embodiment includes a supply and recovery unit 12 for supplying and recovering workpieces W, a processing unit 14 for processing workpieces W, a cleaning unit 16 for cleaning the processed workpieces W, and a transport unit 18 for transporting workpieces W to each unit.

[0026] The supply and recovery unit 12 includes a load port 20 and supplies the workpiece W to be processed from a cassette (not shown) set in the load port 20. The processed workpiece W is also recovered into the cassette (not shown) via the load port 20. The workpiece W is handled while mounted on a dicing frame (not shown). The workpiece W is attached to the dicing frame via dicing tape.

[0027] The machining unit 14 holds the workpiece W on the machining table 22 and performs machining. The machining table 22 is rotatable about the θ axis shown in Figure 1 and is movable along the X direction. The θ axis passes through the center of the machining table 22 and is parallel to the Z axis. The machining unit 14 cuts the workpiece W or machines grooves in the workpiece W by bringing a blade 26 attached to the tip of a high-speed rotating spindle 24 into contact with the workpiece W. In the example shown in Figure 1, the dicing device 10 has two spindles 24 and can machine two locations simultaneously. The configuration of the machining unit 14 will be described later.

[0028] The cleaning unit 16 holds the processed workpiece W on the cleaning table 28 and performs spin cleaning. Specifically, the cleaning unit 16 rotates the cleaning table 28 while supplying cleaning fluid to the workpiece W to clean it. After cleaning is complete, the cleaning unit 16 rotates the cleaning table 28 while blowing air onto the workpiece W to dry it (so-called spin drying).

[0029] The transport unit 18 has a robotic arm 30, which transports the workpiece W to each section. Specifically, the transport unit 18 transports the workpiece W supplied from the supply and recovery unit 12 to the processing unit 14 using the robotic arm 30. The transport unit 18 then transports the workpiece W processed in the processing unit 14 to the cleaning unit 16 using the robotic arm 30. Furthermore, the transport unit 18 transports the workpiece W cleaned in the cleaning unit 16 back to the supply and recovery unit 12 using the robotic arm 30.

[0030] Figure 2 is a perspective view showing the schematic configuration of the machining section.

[0031] As shown in Figure 2, the processing unit 14 has a saddle 32 and a gantry column 34. The saddle 32 and the gantry column 34 are mounted on a frame (not shown).

[0032] The X-axis guide rail 38 is provided on the saddle 32. The X-axis table 36 is attached to the X-axis guide rail 38. The X-axis table 36 is supported so as to be movable along the X-direction, guided by the X-axis guide rail 38. The X-axis table 36 is driven to move by an X-axis motor. The X-axis motor is, for example, a linear motor. The position of the X-axis table 36 on its axis of movement (position in the X-direction) is detected by an X-axis sensor. The X-axis sensor is, for example, a linear scale.

[0033] The X-axis table 36 is equipped with a table unit 40. The table unit 40 includes a machining table 22 for holding a workpiece W and a table drive unit 42 for rotating the machining table 22. The machining table 22 has a disc shape and a workpiece holding surface 22A on its upper surface for holding the workpiece W. The workpiece W is held on the workpiece holding surface 22A, for example, by vacuum suction. The workpiece W is held horizontally. The table drive unit 42 includes a motor, which rotates the machining table 22.

[0034] The gantry column 34 is equipped with a pair of Y-axis tables 44 that move along the Y-direction. Each Y-axis table 44 is supported to move freely along the Y-direction by being guided by a common Y-axis guide rail 46 disposed on the gantry column 34. Each Y-axis table 44 moves independently, for example, by being driven individually by a Y-axis motor. The Y-axis motor is, for example, a linear motor. In addition, the position of each Y-axis table 44 on its axis of movement (position in the Y-direction) is individually detected by a Y-axis sensor. The Y-axis sensor is, for example, a linear scale.

[0035] Each Y-axis table 44 is equipped with a Z-axis table 48 that moves along the Z-direction. Each Z-axis table 48 is supported to move freely along the Z-direction by being guided by a Z-axis guide rail (not shown) disposed on the Y-axis table 44. Each Z-axis table 48 moves independently, for example, by being driven individually by a Z-axis motor. The Z-axis motor is composed of, for example, a linear motor. In addition, the position of each Z-axis table 48 on its axis of movement (position in the Z-direction) is individually detected by a Z-axis sensor. The Z-axis sensor is composed of, for example, a linear scale.

[0036] Each Z-axis table 48 is equipped with a machining unit 50 for machining a workpiece W. The machining unit 50 includes a spindle 24, a spindle drive unit 52 for rotating the spindle 24, and a cutting fluid supply unit (not shown) for supplying cutting fluid. In the example shown in Figure 2, two machining units 50 are facing each other in the direction Y. The two machining units 50 are, for example, arranged in opposite directions in the direction Y. For example, the two machining units 50 are arranged symmetrically with a saddle 32 (or X-axis guide rail 38) in between. The spindle 24 is arranged along the Y direction. The spindle 24 has a blade mounting portion at its tip. The blade 26 is detachably mounted on the blade mounting portion. The configuration of the blade mounting portion will be described later. The spindle drive unit 52 includes a motor, which rotates the spindle 24. The cutting fluid supply unit includes a nozzle, which supplies cutting fluid to the contact area between the blade 26 and the workpiece W.

[0037] As described above, with the machining unit 14 configured as described, the machining table 22 is moved along the X direction by driving the X-axis table 36. This causes the workpiece W to be cut and fed. In addition, the machining unit 50 is moved along the Y direction by driving the Y-axis table 44. This causes the blade 26 to be indexed and fed. Furthermore, the machining unit 50 is moved along the Z direction by driving the Z-axis table 48. This causes the blade 26 to be cut and fed. Also, the orientation (rotation position) of the workpiece W is switched by rotating the machining table 22. Through these operations of the machining unit 14, the workpiece W is cut or grooves are machined into the workpiece W.

[0038] [Blade mounting section] Figure 3 is a cross-sectional view showing the configuration of the blade mounting section. In Figure 3, the blade mounting section 60 of the processing unit 50 located at the tip of the arrow in the Y direction, one of the two processing units 50 shown in Figure 2, will be used for explanation. The configuration of the blade mounting section 60 of the processing unit 50 shown in Figure 3 can be applied to the blade mounting sections of other processing units 50.

[0039] In this embodiment, a so-called hubless blade is used for the blade 26. A hubless blade is a blade without a hub. However, it is also possible to use a hub blade equipped with a hub. The blade 26 has a disc shape and a circular mounting hole 26A in the center.

[0040] As described above, the blade 26 is detachably attached to the tip of the spindle 24 via the blade mounting portion 60.

[0041] The blade mounting section 60 consists of a flange mounting section 24B provided at the tip of the spindle 24, a rear flange 70 attached to the flange mounting section 24B, a fixing screw 72 for fixing the rear flange 70 to the flange mounting section 24B, a front flange 74 for sandwiching and fixing the blade 26 between itself and the rear flange 70, and a fixing nut 76 for fixing the front flange 74. The blade mounting section 60 rotates in accordance with the rotation of the spindle 24.

[0042] The flange mounting portion 24B has a tapered shape (frustum shape) in which the diameter decreases towards the tip. The flange mounting portion 24B is integrally provided at the tip of the spindle body 24A. The spindle 24 is positioned so that the flange mounting portion 24B protrudes from the tip of the housing 52A of the spindle drive unit 52. More specifically, it protrudes from the opening 80A of the tip cover 80 attached to the tip of the housing 52A. The tip cover 80 is fixedly attached to the tip of the housing 52A of the spindle drive unit 52 by bolts 82.

[0043] The rear flange 70 is mainly composed of a rear flange body 70A and a flange portion 70B. The rear flange body 70A has a cylindrical shape. The rear flange body 70A has a hole on its inside into which the flange mounting portion 24B is fitted. The hole formed on the inside of the rear flange body 70A has a shape that matches the shape of the flange mounting portion 24B. That is, the inner circumference of the hole in the rear flange body 70A has a tapered shape corresponding to the shape of the flange mounting portion 24B. The flange portion 70B has a disc shape and is integrally provided on the outer circumference of the base end of the rear flange body 70A. The flange portion 70B is provided with a blade fitting portion 70C on the end face opposite to the tip of the arrow in the Y direction (hereinafter sometimes referred to as the front side or tip side). The blade fitting portion 70C has a shape corresponding to the mounting hole 26A of the blade 26. The blade 26 is held coaxially on the rear flange 70 by fitting its mounting hole 26A into the blade fitting portion 70C.

[0044] The fixing screw 72 is screw-connected to the tip of the flange mounting portion 24B. The flange mounting portion 24B is provided with a screw hole 24C into which the fixing screw 72 is screw-connected. The screw hole 24C is formed at the tip of the flange mounting portion 24B, along the axis of the spindle 24.

[0045] The rear flange 70 is mounted coaxially with the flange mounting portion 24B by fitting its inner circumference into the flange mounting portion 24B. After mounting, the fixing screws 72 are inserted into the screw holes 24C of the flange mounting portion 24B and tightened, thereby pressing the rear flange 70 against the flange mounting portion 24B and fixing it integrally with the flange mounting portion 24B.

[0046] The front flange 74 has a disc-like shape and a circular hole 74A in its center. The front flange 74 is attached to the rear flange 70 by fitting the hole 74A into the rear flange body 70A.

[0047] The fixing nut 76 is screw-connected to the tip of the rear flange body 70A. The tip of the rear flange body 70A is provided with a male threaded portion 70D to which the fixing nut 76 is screw-connected.

[0048] The blade 26 is mounted on the blade mounting section 60. Here, the method of mounting the blade 26 to the blade mounting section 60 will be explained. First, the rear flange 70 is mounted on the spindle 24. The rear flange 70 is mounted on the flange mounting section 24B by fitting its inner circumference into the flange mounting section 24B. After mounting, the rear flange 70 is fixed to the flange mounting section 24B with fixing screws 72. Next, the blade 26 is mounted on the rear flange 70. The blade 26 is mounted on the rear flange 70 by fitting its mounting hole 26A into the blade fitting section 70C provided on the flange section 70B of the rear flange 70. After that, the front flange 74 is mounted on the rear flange 70. The front flange 74 is mounted on the rear flange 70 by passing the rear flange body 70A through the central hole 74A. After mounting the front flange 74, the fixing nut 76 is fitted onto the male threaded section 70D of the rear flange 70 and tightened. This causes the blade 26 to be sandwiched and fixed between the rear flange 70 and the front flange 74.

[0049] [Elastic wave detection unit] The dicing apparatus 10 of this embodiment includes an elastic wave detection unit 90 that detects elastic waves generated from the blade 26. The elastic wave detection unit 90 includes an AE sensor 92. AE stands for acoustic emission. Acoustic emission is a phenomenon in which, when a material deforms or breaks, it releases the strain energy stored inside as elastic waves (AE waves). AE waves have very high frequency components, ranging from several kHz to several MHz. Since high-frequency signals are greatly attenuated in air, AE waves mainly propagate through objects. The AE sensor 92 detects these AE waves and converts them into electrical signals for output. AE sensors generally use piezoelectric elements such as PZT (lead zirconate titanate) to detect AE waves. Note that the AE sensor itself has a known configuration, so a detailed explanation will be omitted.

[0050] In the dicing apparatus 10 of this embodiment, the AE sensor 92 is attached to the blade mounting section 60. Since the blade mounting section 60 is a rotating body, in this embodiment, a coil is used to transmit the signal from the AE sensor 92 to the outside. The configuration of the elastic wave detection unit 90 and its mounting structure will be described below.

[0051] As shown in Figure 3, the elastic wave detection unit 90 comprises an AE sensor 92, a transmitting coil 94 electrically connected to the AE sensor 92, and a receiving coil 96 magnetically coupled to the transmitting coil 94. The AE sensor 92 and the transmitting coil 94 are mounted on the rear flange 70, which is a rotating body. On the other hand, the receiving coil 96 is mounted on a non-rotating tip cover 80 fixed to the tip of the housing 52A. Note that an object that does not rotate relative to a rotating body is sometimes referred to as a "fixed body".

[0052] Figure 4 is a rear view of the rear flange.

[0053] As shown in the figure, the rear flange 70 is provided with an AE sensor mounting portion 70E, a balance weight mounting portion 70F, and a transmitting coil mounting portion 70G on the back surface of the flange portion 70B.

[0054] The AE sensor mounting portion 70E and the balance weight mounting portion 70F are composed of recesses of the same shape and are arranged symmetrically with respect to the axis of the rear flange 70. The AE sensor 92 is housed in the AE sensor mounting portion 70E and attached to the rear flange 70.

[0055] A balance weight 98 is attached to the balance weight mounting section 70F. The balance weight 98 is a weight that balances the rotation of the rear flange 70. By attaching the balance weight 98, stable rotation without wobble can be ensured even when the spindle 24 is rotated at high speed.

[0056] The transmitting coil mounting section 70G is composed of an annular recess and is positioned coaxially with the axis of the rear flange 70, which serves as the axis of rotation. The transmitting coil 94 is housed in the transmitting coil mounting section 70G and attached to the rear flange 70. The transmitting coil 94 attached to the rear flange 70 is wound around the axis (axis of rotation) of the rotating rear flange 70.

[0057] Figure 5 is a front view of the tip cover.

[0058] As shown in Figure 5, the tip side surface of the tip cover 80 is provided with a receiver coil mounting portion 80B. The receiver coil mounting portion 80B is composed of an annular recess and is arranged coaxially with the transmitter coil mounting portion 70G. The receiver coil 96 is housed in the receiver coil mounting portion 80B and attached to the tip cover 80. The receiver coil 96 attached to the tip cover 80 is arranged coaxially with the transmitter coil 94. Therefore, like the transmitter coil 94, it is wound around the axis (rotation axis) of the rear flange 70.

[0059] With the above configuration, the transmitting coil 94 and the receiving coil 96 are positioned facing each other with a predetermined gap between them, and are magnetically coupled in a non-contact state. Furthermore, with this configuration, the signal output from the AE sensor 92 is transmitted to the receiving coil 96 by mutual induction between the transmitting coil 94 and the receiving coil 96.

[0060] [Cutter Set] In the dicing device 10, the height of the blade 26 relative to the processing table 22 is precisely controlled to achieve high-precision machining. The height of the blade 26 is controlled by detecting the position where the blade 26 contacts the surface of the processing table 22. This process is called cutter setting and is performed periodically. The detected position is set as the reference position of the blade 26, and the cutting feed of the blade 26 is controlled based on this reference position information. In addition, the amount of wear of the blade 26 is measured based on this reference position information. That is, the change in the diameter of the blade 26 (amount of wear) is calculated from the change in the reference position.

[0061] In the dicing apparatus 10 of this embodiment, when setting the cutter, contact of the blade 26 with the processing table 22 is detected based on the output of the elastic wave detection unit 90.

[0062] The cutter set is executed by the system controller 100 in response to a cutter set execution command. Execution commands include both manual and automatic commands. In the manual case, the operator manually inputs the command via the control panel (not shown) of the dicing device 10. In the automatic case, the command is automatically input at specific timings. For example, the execution command is automatically input when a certain amount of time has elapsed since the blade 26 was replaced, or when a certain number of workpieces have been processed since the blade 26 was replaced.

[0063] The system controller 100 is a control unit that provides overall control over the operation of the dicing device 10, and is composed of, for example, a computer equipped with a processor and memory. The processor is composed of, for example, a CPU (central processing unit). The memory includes RAM (random access memory) and ROM (read-only memory).

[0064] The system controller 100 controls the drive of the spindle drive unit 52 and the Z-axis motor 48M to perform the cutter set processing.

[0065] Figure 6 is a block diagram of the main functions of the system controller with respect to the cutter set.

[0066] As shown in Figure 6, with respect to the cutter set, the system controller 100 has functions such as a spindle rotation control unit 110, a cutting feed control unit 112, a contact detection unit 114, and a reference position setting unit 116. Each function is realized by the processor by executing a predetermined control program. The control program is stored in memory or storage unit 102. The storage unit 102 is composed of, for example, flash memory.

[0067] The spindle rotation control unit 110 controls the drive of the spindle drive unit 52 to control the rotation of the blade 26.

[0068] The cutting feed control unit 112 controls the drive of the Z-axis motor 48M to control the feed (cutting feed) of the blade 26 in the Z-axis direction.

[0069] The contact detection unit 114 processes the signal output from the elastic wave detection unit 90 (the output signal from the AE sensor 92) to detect contact between the blade 26 and the processing table 22.

[0070] Figure 7 is a graph showing an example of the output of an AE sensor. In the graph shown in this figure, the horizontal axis represents time, and the vertical axis represents the output of the AE sensor (output voltage of the piezoelectric element [V]). Figure 7(A) shows an example of the output of the AE sensor when the blade is idling. Figure 7(B) shows an example of the output of the AE sensor when the blade comes into contact with the machining table midway through the process. Figure 7(B) is an example where the blade comes into contact with the machining table at time T1.

[0071] As shown in Figure 7(A), when the blade 26 is free-spinning, that is, when nothing is in contact with the blade 26, the output of the AE sensor 92 is lower than when it is in contact, and remains within a nearly constant range.

[0072] On the other hand, as shown in Figure 7(B), when the blade 26 comes into contact with the processing table 22 midway through the process, the output of the AE sensor 92 increases.

[0073] The contact detection unit 114 monitors the signal output from the elastic wave detection unit 90 and detects when the blade 26 has come into contact with the processing table 22. Specifically, it compares the signal output from the elastic wave detection unit 90 with a threshold Th, and determines that the blade 26 has come into contact with the processing table 22 if the signal output from the elastic wave detection unit 90 exceeds the threshold.

[0074] The reference position setting unit 116 sets the reference position of the blade 26 based on the output of the contact detection unit 114 and the output of the Z-axis sensor 48S. Specifically, the position of the Z-axis table 48 detected when contact of the blade 26 with the processing table 22 is detected is set as the reference position of the blade 26. The information of the set reference position is recorded in the storage unit 102.

[0075] [Processing the cutter set] Figure 8 is a flowchart showing the processing procedure for the cutter set.

[0076] First, it is determined whether or not there is an execution command for the cutter set (step S1). As described above, the cutter set can be entered manually via the operating unit, or automatically at specific timings.

[0077] When the cutter set execution command is input, the blade 26 is set to the origin position (step S2). The origin position is set to a position where the blade 26 does not come into contact with the machining table 22, i.e., a position where it is spaced apart.

[0078] Next, the blade 26 is fed towards the machining table 22 while rotating (step S3).

[0079] When the cutting feed of the blade 26 is started, the contact detection unit 114 detects contact of the blade 26. Based on the output of the AE sensor 92, the contact detection unit 114 determines whether or not the blade 26 has come into contact with the machining table 22 (step S4). More specifically, it determines whether or not the blade 26 has come into contact with the machining table 22 by determining whether or not the output of the AE sensor 92 exceeds a threshold.

[0080] When contact with the blade 26 is detected, a reference position is set (step S5). That is, information about the position of the Z-axis table 48 at the time contact with the blade 26 is detected is obtained, and the obtained position is set as the reference position of the blade 26. The information of the set reference position is stored in the storage unit 102.

[0081] Furthermore, when contact with the blade 26 is detected, the blade 26 is returned to its origin position and its rotation is stopped (step S6).

[0082] The cutter set processing is completed with the above series of steps. Thereafter, the cutting feed of the blade 26 is controlled based on the set reference position. In addition, the amount of wear on the blade 26 is measured based on the information of the set reference position.

[0083] In this embodiment, the dicing apparatus 10 is equipped with two processing units 50, so cutter setting is performed for each processing unit 50.

[0084] As described above, the dicing apparatus 10 of this embodiment detects contact of the blade 26 based on the output of the AE sensor 92, so the height relationship between the blade 26 and the processing table 22 can be controlled with high precision regardless of the type of blade 26. Therefore, for example, blades that do not have conductivity can also be used.

[0085] Furthermore, according to the dicing apparatus 10 of this embodiment, since the AE sensor 92 is attached to the blade mounting section 60, elastic waves (elastic waves caused by the blade) generated from the blade 26 can be detected with high accuracy. That is, since the AE sensor 92 is attached to the member that directly holds the blade 26, elastic waves generated from the blade 26 can be detected with almost no attenuation. Also, even if there are multiple processing units 50, elastic waves generated from the blade 26 of each processing unit 50 can be detected with high accuracy. Moreover, by providing a dedicated mounting section on the rear flange 70 and attaching the AE sensor 92 and the transmitting coil 94 there, the AE sensor 92 and the transmitting coil 94 can be firmly fixed to the rotating rear flange 70. As a result, it can be used safely even when the spindle 24 is rotating at high speed.

[0086] In the above embodiment, the blade 26 is configured to be in direct contact with the processing table 22. However, it is also possible to attach a cutter setting component (a component whose positional relationship with the processing table 22 is known) to the processing table 22, and then bring the blade 26 into contact with this component to perform the cutter setting. In this case as well, it is essentially included in a configuration in which the blade 26 is in contact with the processing table 22.

[0087] (modified version) In the above embodiment, the AE sensor 92 is attached to the blade mounting section 60 to detect elastic waves generated from the blade 26. However, the location where the AE sensor 92 is attached is not limited to this. Other examples of attachment locations for the AE sensor 92 will be described below.

[0088] [Example of mounting on a spindle] The blade 26 is integrated with the spindle 24 via the blade mounting portion 60. Therefore, the elastic waves generated from the blade 26 are also propagated to the spindle 24. Consequently, even when the AE sensor 92 is attached to the spindle 24, the elastic waves generated from the blade 26 can be detected.

[0089] Figure 9 shows an example of a mounting structure for an AE sensor on a spindle.

[0090] As shown in the figure, in this example, the AE sensor 92 is built into the tip of the spindle 24 (the end on the blade mounting portion 60 side).

[0091] The spindle 24 is provided with a hole 24D that extends along its axis from the base to the tip. The hole 24D is positioned coaxially with the rotation axis of the spindle 24. The AE sensor 92 is housed in the hole 24D of the spindle 24 and is fixedly mounted to the tip of the hole 24D.

[0092] A transmitting bobbin 94A, equipped with a transmitting coil 94, is attached to the base end of the spindle 24. The transmitting coil 94 is wound around the axis of rotation of the spindle 24, which is a rotating body. The AE sensor 92 is electrically connected to the transmitting coil 94 via a wire 93 located in the hole 24D.

[0093] An end cap 84 is attached to the base end of the housing 52A of the spindle drive unit 52, which is the fixed part. A receiving bobbin 96A, which has a receiving coil 96 on its inner surface, is attached to the end cap 84. The receiving coil 96 is wound around the rotation axis of the spindle 24 and is positioned opposite the transmitting coil 94 with a predetermined gap between them. As a result, the transmitting coil 94 and the receiving coil 96 are magnetically coupled in a non-contact state.

[0094] With the above configuration, the AE sensor 92 is attached to the spindle 24. The signal output from the AE sensor 92 is transmitted to the receiving coil 96 by mutual induction between the transmitting coil 94 and the receiving coil 96.

[0095] As described above, since the blade 26 is integrated with the spindle 24 via the blade mounting portion 60, elastic waves generated from the blade 26 can be detected even when the AE sensor 92 is attached to the spindle 24. In particular, in this example, since the AE sensor 92 is attached to the tip side (blade mounting portion side) of the spindle 24, elastic waves generated from the blade 26 can be detected with almost no attenuation. Also, in this example, since the AE sensor 92 and the transmitting coil 94 are mounted coaxially with the spindle 24, the spindle 24 can be rotated stably. Since the AE sensor 92 is built into the spindle 24, it can be firmly fixed.

[0096] [Example of attachment to a processing table] As described above, the cutter set detects contact between the blade 26 and the processing table 22 by detecting a specific pattern of elastic waves generated when the blade 26 contacts the processing table 22 using the AE sensor 92. These specific pattern of elastic waves are also propagated to the processing table 22. Therefore, even if the AE sensor 92 is attached to the processing table 22, contact with the blade 26 can be detected from the output of the AE sensor 92.

[0097] Figure 10 shows an example of a mounting structure for an AE sensor on a machining table.

[0098] As shown in the figure, the AE sensor 92 and transmitting coil 94 are attached to the machining table 22, which is a rotating body, and the receiving coil 96 is attached to the table drive unit 42, which is a stationary body. The AE sensor 92 and transmitting coil 94 are attached to the machining table 22 via the sensor base 86. The receiving coil 96 is attached to the table drive unit 42 via the coil base 88.

[0099] Figure 11 is a bottom view of the sensor base.

[0100] As shown in Figure 11, the sensor base 86 has an annular shape. The lower surface of the sensor base 86 is provided with an AE sensor mounting portion 86A, a balance weight mounting portion 86B, and a transmitting coil mounting portion 86C.

[0101] The AE sensor mounting portion 86A and the balance weight mounting portion 86B are composed of recesses of the same shape and are arranged symmetrically with respect to the axis of the sensor base 86 (= the rotation axis of the machining table 22). The AE sensor 92 is housed in the AE sensor mounting portion 86A and attached to the sensor base 86.

[0102] A balance weight 98 is attached to the balance weight mounting section 86B. The balance weight 98 is a weight that balances the rotation of the sensor base 86.

[0103] The transmitting coil mounting section 86C is composed of an annular recess and is positioned coaxially with the axis of the sensor base 86. The transmitting coil 94 is housed in the transmitting coil mounting section 86C and attached to the sensor base 86. As a result, the transmitting coil 94 is wound around the axis of the sensor base 86.

[0104] As shown in Figure 10, the sensor base 86 with the above configuration is mounted coaxially on the lower surface of the machining table 22 and integrated with the machining table 22. By mounting the sensor base 86 to the machining table 22, the transmitting coil 94 is connected to the rotation axis of the machining table 22. They are arranged coaxially and wound around it.

[0105] Figure 12 is a top view of the coil base.

[0106] As shown in Figure 12, the coil base 88 has an annular shape. The upper surface of the coil base 88 is provided with a receiving coil mounting portion 88A. The receiving coil mounting portion 88A is composed of an annular recess and is arranged coaxially with the coil base 88. The receiving coil 96 is housed in the receiving coil mounting portion 88A and attached to the coil base 88. As a result, the receiving coil 96 is wound around the axis of the coil base 88.

[0107] As shown in Figure 10, the coil base 88 with the above configuration is attached to the upper end of the housing 42A of the table drive unit 42 and is positioned coaxially with the rotation axis of the machining table 22. As a result, the receiving coil 96 is positioned coaxially with the rotation axis of the machining table 22 and wound around it. In addition, the receiving coil 96 is positioned on the same circumference as the transmitting coil 94.

[0108] With the above configuration, the transmitting coil 94 and the receiving coil 96 are positioned facing each other with a predetermined gap between them, and are magnetically coupled in a non-contact state. Furthermore, with this configuration, the signal output from the AE sensor 92 is transmitted to the receiving coil 96 by mutual induction between the transmitting coil 94 and the receiving coil 96.

[0109] When the blade 26 comes into contact with the processing table 22, the elastic waves generated at the time of contact are detected by the AE sensor 92. This allows the contact of the blade 26 to be detected.

[0110] (Second Embodiment) As mentioned above, by equipping the dicing device 10 with an elastic wave detection unit 90, contact between the blade 26 and the processing table 22 can be detected. This makes it possible to perform a contact-type cutter setting regardless of the type of blade 26.

[0111] In a dicing apparatus 10 equipped with an elastic wave detection unit 90, the state of the workpiece W and the blade 26 can be estimated by monitoring the elastic waves generated from the blade 26 during processing. The estimation of the state of the workpiece W and the blade 26 using elastic waves will be described below.

[0112] [Estimation of the workpiece state] Figure 13 is a schematic diagram of the cutting line as seen from above.

[0113] Normally, the workpiece W is cut at the center of the street (st). Figure 13 shows an example where the center of the kerf (groove) K (kerf center) KC is offset from the street center StC during cutting. When the street center StC and the kerf center KC are misaligned, a center misalignment occurs. The amount of misalignment between the street center StC and the kerf center KC is the center misalignment amount ε.

[0114] Figure 14 is a schematic diagram of the occurrence of chipping. Figure 14 shows the state when cutting a wafer (workpiece W) attached to a dicing tape DT. The symbols FB in Figure 14 represent foreign matter. Chipping C occurs at the kerf edge (boundary with the street). Chipping refers to unintended cracks or chips that occur at the corners or edges of the kerf line of the workpiece. Chipping can occur due to various factors such as blade clogging, fluctuations in the amount of cutting fluid, changes in the appearance of the workpiece material, and operator setting errors.

[0115] When chipping occurs, the deformation and fracture patterns may differ from normal cutting, resulting in the generation of elastic waves that are different from those during stable operation. Therefore, by monitoring the elastic waves generated from the blade, it is possible to detect the occurrence of chipping (chipping exceeding acceptable limits).

[0116] Figure 15 is a graph showing an example of the output of an AE sensor during machining. Figure 15(A) shows an example of the output of the AE sensor during stable cutting. Figure 15(B) shows an example of the output of the AE sensor when chipping occurs suddenly. Figure 15(B) is an example where chipping occurs at times T2 and T3.

[0117] As shown in Figure (A), when the machining (cutting) is stable, the output of the AE sensor 92 remains within a nearly constant range. In other words, the output is nearly uniform.

[0118] On the other hand, as shown in Figure (B), when sudden chipping occurs, the output of the AE sensor 92 fluctuates significantly from its stable trend.

[0119] Figure 16 is a graph showing an example of the output of an AE sensor during machining. This figure shows an example of the AE sensor output when chipping is continuously occurring.

[0120] Due to differences in the amount of cutting fluid used or operator setting errors, chipping exceeding the permissible limit may occur continuously. In this case, the output of the AE sensor 92 will continue to take a value different from that of the stable state. Therefore, by comparing it with the output of the stable state (see Figure 15(A)), the abnormality can be detected.

[0121] [Estimation of blade condition] Figure 17 is a schematic diagram of a blade during machining.

[0122] Blade 26 achieves optimal machining (cutting) by balancing the abrasive grains (cutting particles) AC, the binder (bonding agent) BO that binds the abrasive grains AC together, and the density (chip pocket) CP that determines how much space is left between them when they are bonded.

[0123] The workpiece W is machined while the cutting fluid CL is applied to the blade 26. When the workpiece W is cut, so-called chips (cutting dust) SW are generated. Also, some abrasive grains AC are detached from the blade 26. Good cutting is achieved when these chips SW and detached abrasive grains are appropriately separated from the blade 26 along with the cutting fluid CL. On the other hand, if the balance is disrupted, foreign matter will clog the chip pocket CP of the blade 26. This phenomenon is called "clogging". When clogging occurs in the blade 26, the output of the AE sensor 92 fluctuates.

[0124] Figure 18 is a graph showing an example of the output of the AE sensor during machining. In Figure 18, graph G1, shown by the thick line, shows an example of the output of the AE sensor 92 when clogging occurs in the blade. On the other hand, graph G2, shown by the thin line, shows an example of the output of the AE sensor 92 when it is stable and not clogging.

[0125] As shown in Figure 18, when clogging occurs in the blade 26, the output of the AE sensor 92 fluctuates in steps from a stable state. Therefore, by comparing it with the output of the AE sensor 92 when it is stable, the state of clogging can be estimated.

[0126] [Device configuration] The dicing apparatus 10 of this embodiment has a function to estimate the state of the workpiece W based on elastic waves generated from the blade 26, and a function to estimate the state of the blade 26. This function is implemented by the system controller 100.

[0127] The device configuration is substantially the same as that of the dicing apparatus 10 in the first embodiment. Therefore, only the functions of the system controller 100 described above will be explained here.

[0128] Figure 19 is a block diagram of the functions of the system controller related to estimation.

[0129] As shown in Figure 19, with regard to the estimation process, the system controller 100 has a work state estimation unit 120 that estimates the state of the workpiece W, and a blade state estimation unit 122 that estimates the state of the blade 26. Each unit is implemented by the processor by executing a predetermined program. The program is stored in memory or storage unit 102.

[0130] The workpiece state estimation unit 120 acquires the signal output from the elastic wave detection unit 90 (the output signal from the AE sensor 92) and estimates the state of the workpiece W, in particular, whether or not chipping has occurred. In this embodiment, the state of the workpiece W is estimated by comparing it with the signal obtained during stable cutting.

[0131] As described above, if chipping exceeding the tolerance limit occurs suddenly, the output of the AE sensor 92 will deviate significantly from its stable trend (see Figure 15(B)). Furthermore, if chipping exceeding the tolerance limit continues to occur, the output of the AE sensor 92 will continue to take a value different from that of a stable state (see Figure 16).

[0132] Therefore, the workpiece state estimation unit 120 compares the output signal from the AE sensor 92 obtained during machining with the output signal obtained from the AE sensor 92 during stable cutting to detect (estimate) the occurrence of chipping. For example, it sets a threshold based on the output signal obtained during stable cutting and detects signals that exceed the threshold to detect (estimate) sudden chipping. Alternatively, for example, it sets a threshold based on the output signal obtained during stable cutting and detects (estimates) continuous chipping if signals exceeding the threshold are detected more than a specified number of times within a specified time.

[0133] The blade state estimation unit 122 acquires the signal output from the elastic wave detection unit 90 and estimates the state of the blade 26, particularly the state of clogging. In this embodiment, the state of clogging is estimated by comparing it with the signal obtained during stable cutting.

[0134] As described above, when clogging occurs in the blade 26, the output of the AE sensor 92 fluctuates in steps from a stable state. Therefore, by comparing it with the output signal of the AE sensor 92 when it is stable, the state of clogging can be estimated.

[0135] The blade state estimation unit 122 calculates the fluctuation trend of the output signal of the AE sensor 92, for example, using a statistical method, and estimates the occurrence of clogging by comparing it with the fluctuation trend of the output signal obtained when the blade is stable. In other words, if the calculated fluctuation trend differs from the fluctuation trend when the blade is stable (especially if the output signal deviates from the stable output signal over time), it is estimated that clogging exceeding the allowable limit has occurred.

[0136] Information on the output signal of the AE sensor 92 obtained during stable cutting is acquired in advance and stored in the memory unit 102. Note that the output signal of the AE sensor 92 obtained during stable cutting differs depending on the machining conditions (type of blade used, etc.), so a separate signal is prepared for each machining condition.

[0137] As described above, according to the dicing apparatus 10 of this embodiment, the state of the workpiece W and the blade 26 can be estimated using the elastic wave detection unit 90.

[0138] The estimation results are displayed on the display unit (not shown). Furthermore, if chipping or clogging exceeding the permissible limits is detected (estimated), a warning will be issued.

[0139] In this embodiment, the system is configured to estimate the state of both the workpiece W and the blade 26, but it is also possible to configure the system to estimate only the state of one of them.

[0140] In the above embodiment, when the blade 26 is fed into the cutting groove, the processing unit 50 is moved relative to the processing table 22. However, the processing table 22 may be moved instead. Alternatively, both may be moved. In other words, the movement of the spindle 24 and the processing table 22 may be relative. [Explanation of Symbols]

[0141] 10…Dicing device, 12…Supply and recovery unit, 14…Processing unit, 16…Washing unit, 18…Conveying unit, 20…Load port, 22…Processing table, 22A…Workpiece holding surface, 24…Spindle, 24A…Spindle body, 24B…Spindle flange mounting part, 24C…Spindle screw hole, 24D…Spindle hole, 26…Blade, 26A…Blade mounting hole, 28…Washing table, 30…Robot arm, 32…Saddle, 34…Gantry column, 36…X-axis table, 38…X-axis guide rail, 40…Table unit, 42…Table drive unit, 42A… Table drive unit housing, 44...Y-axis table, 46...Y-axis guide rail, 48...Z-axis table, 48M...Z-axis motor, 48S...Z-axis sensor, 50...Machining unit, 52...Spindle drive unit, 52A...Spindle drive unit housing, 60...Blade mounting section, 70...Rear flange, 70A...Rear flange body, 70B...Flange section of rear flange, 70C...Blade fitting section of rear flange, 70D...Male threaded section of rear flange, 70E...AE sensor mounting section of rear flange, 70F...Balance weight mounting section of rear flange, 70G...Transmitter coil of rear flange Mounting part, 72... Fixing screw, 74... Front flange, 74A... Hole in front flange, 76... Fixing nut, 80... Tip cover of spindle drive housing, 80A... Opening, 80B... Receiving coil mounting part, 82... Bolt, 84... End cap, 86... Sensor base, 86A... AE sensor mounting part on sensor base, 86B... Balance weight mounting part on sensor base, 86C... Transmitting coil mounting part on sensor base, 88... Coil base, 88A... Receiving coil mounting part on coil base, 90... Elastic wave detection part, 92... AE sensor, 93... Wire, 94... Transmitting coil 94A…Transmitting bobbin, 96…Receiving coil, 96A…Receiving bobbin, 98…Balance weight, 100…System controller, 102…Storage unit, 110…Spindle rotation control unit, 112…Cutting feed control unit, 114…Contact detection unit, 116…Reference position setting unit, 120…Workpiece state estimation unit, 122…Blade state estimation unit, AC…Abrasive grain, C…Chipping, CL…Cutting fluid, CP…Chip pocket, DT…Dicing tape, KC…Kerf center, SW…Chip, St…Street, StC…Street center, W…Workpiece, ε…Center misalignment

Claims

1. A table that holds the workpiece, A spindle that moves relative to the table, A blade mounting portion integrally attached to the spindle, A blade to be mounted on the blade mounting section, An elastic wave detection unit for detecting elastic waves, A contact detection unit detects contact between the blade and the table based on the signal output from the elastic wave detection unit, A reference position setting unit for setting the reference position of the blade, Prepare, The elastic wave detection unit is An AE sensor is attached to the table, A transmitting coil is mounted on the table and connected to the AE sensor, A receiving coil is positioned opposite the transmitting coil and is magnetically coupled to the transmitting coil, Equipped with, The signal output from the AE sensor is transmitted to the receiving coil via the transmitting coil by mutual induction between the transmitting coil and the receiving coil. The reference position setting unit moves the spindle and the table relative to each other along the Z direction from a position where the blade and the table are separated, and sets the position where contact is detected by the contact detection unit as the reference position of the blade. Dicing device.

2. A table that holds the workpiece, A spindle that moves relative to the table, A blade mounting portion integrally attached to the spindle, A blade to be mounted on the blade mounting section, An elastic wave detection unit for detecting elastic waves, Prepare, The elastic wave detection unit is An AE sensor is built into the tip of the spindle and is in contact with the spindle. A transmitting coil is attached to the base end of the spindle and connected to the AE sensor, A receiving coil is positioned opposite the transmitting coil and is magnetically coupled to the transmitting coil, Equipped with, The signal output from the AE sensor is transmitted to the receiving coil via the transmitting coil by mutual induction between the transmitting coil and the receiving coil. Dicing device.

3. A table that holds the workpiece, A spindle that moves relative to the table, A blade mounting portion integrally attached to the spindle, A blade to be mounted on the blade mounting section, An elastic wave detection unit for detecting elastic waves, Prepare, The elastic wave detection unit is An AE sensor attached to the blade mounting portion and a transmitting coil connected to the AE sensor, and a receiving coil positioned opposite the transmitting coil and magnetically coupled to the transmitting coil, Equipped with, The signal output from the AE sensor is transmitted to the receiving coil via the transmitting coil by mutual induction between the transmitting coil and the receiving coil. The blade mounting section is provided with a plurality of flanges, The AE sensor is attached to at least one of the plurality of flanges, The blade is held directly in the blade mounting portion by being sandwiched and fixed between the plurality of flanges. Dicing device.

Images