Blade Detector

Abstract

To provide a blade detection device that can accurately detect the state of a blade.SOLUTION: A blade detection device includes a detection unit 12 which has a light projection part 26 that has a light projection surface 36 that is opposed to a side surface of a blade 102 and a light reception part 28 that has a light reception surface 44 that is opposed to the light projection surface 36 with the blade 102 held therebetween, and projects light from the light projection surface 36 to the light reception surface 44; a cleaning member 70 which cleans the light projection surface 36 and the light reception surface 44 by coming into contact with the light projection surface 36 and the light reception surface 44 using at least one of the cutting water and cooling water as the cleaning liquid; and movement means (feeding mechanism 14) which relatively moves the cleaning member 70 with respect to the detection unit 12 between the cleaning position being in contact with the light projection surface 36 and the light reception surface 44 and the retreat position separated from the cleaning position.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a blade detection device and a method for cleaning the blade detection device, and more particularly to a blade detection device that detects the state of a blade of a dicing device, such as wear or damage, and a method for cleaning the blade detection device. [Background technology]

[0002] A dicing machine, which divides a workpiece on which a semiconductor device or electronic component is formed into individual chips, is equipped with a blade that is rotated at high speed by a spindle and a table that holds the workpiece by suction. The dicing machine performs grooving or cutting on the workpiece held by suction on the table using the blade that rotates at high speed.

[0003] In the above-described dicing apparatus, for example, the dicing apparatus disclosed in Patent Document 1 is equipped with a blade detection device that detects the state of the blade, such as wear or damage.

[0004] The blade detection device is attached to a wheel cover that covers the blade and includes a detection unit having a light-emitting section that emits light toward the blade and a light-receiving section that is located opposite the light-emitting section across the blade and receives the light from the light-emitting section.The blade detection device also includes a moving means that moves the detection unit toward the center of rotation of the blade, and a control section that detects the state of the blade based on changes in the amount of light received by the light-receiving section of the detection unit, controls the moving means to move the detection unit toward the center of rotation of the blade, and calculates the amount of blade wear by integrating the amount of movement. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-231760 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since the above-mentioned blade detection device is installed in a misty environment containing cutting powder generated during machining of a workpiece, the following problems arise.

[0007] In other words, if the cutting powder adheres to the light-emitting surface or light-receiving surface of the detection unit that is exposed to the outside, the amount of light received by the light-receiving unit decreases. In this case, the blade detection device may detect an amount of wear that is less than the actual amount of wear, and may not be able to accurately detect the condition of the blade (worn or damaged).

[0008] The present invention has been made in view of the above problems, and has as its object to provide a blade detection device that can accurately detect the state of the blade, and a method for cleaning the blade detection device. [Means for solving the problem]

[0009] In order to achieve the object of the present invention, the blade detection device of the present invention comprises a light-projecting section having a light-projecting surface positioned at a distance from the side of the blade, and a light-receiving section having a light-receiving surface positioned opposite the light-projecting surface across the blade, and is equipped with a detection unit that projects light from the light-projecting surface toward the light-receiving surface, a cleaning member that comes into contact with the light-projecting surface and the light-receiving surface to clean them, and a moving means that moves the detection unit and the cleaning member relatively between a retracted position where the cleaning member is spaced from the light-projecting surface and the light-receiving surface, and a cleaning position where the cleaning member is in contact with the light-projecting surface and the light-receiving surface.

[0010] In one embodiment of the blade detection device of the present invention, it is preferable that the blade detection device is formed of an elastic member that is elastically deformable.

[0011] In one embodiment of the blade detection device of the present invention, the cleaning member is preferably a sponge having an open-cell structure, a semi-closed-cell structure, or a closed-cell structure.

[0012] In one embodiment of the blade detection device of the present invention, the cleaning member is preferably formed in a roll shape having an axis.

[0013] In one form of the blade detection device of the present invention, the cleaning member is preferably rotatable around an axis, and when the cleaning member is in the cleaning position, the cleaning member is preferably positioned at a position offset closer to either the light-emitting surface or the light-receiving surface than the other.

[0014] In one aspect of the blade detection device of the present invention, the cleaning member is preferably arranged to be slidable along the axis.

[0015] One embodiment of the blade detection device of the present invention has a feeding means for driving the detection unit toward the center of rotation of the blade, and the feeding means preferably also serves as the moving means.

[0016] One form of the blade detection device of the present invention preferably includes a light receiving amount detection unit that detects the amount of light received by the light receiving unit, a calculation unit that calculates the rate of change of the amount of light received per unit time, a determination unit that determines whether cleaning of the light-emitting surface and the light-receiving surface is necessary based on the amount of light received and the rate of change, and a drive control unit that drives the moving means to relatively move the cleaning member from the retracted position to the cleaning position when the determination unit determines that cleaning is necessary.

[0017] One form of the blade detection device of the present invention preferably includes a light receiving amount detection unit that detects the amount of light received by the light receiving unit, a judgment unit that judges whether cleaning of the light emitting surface and the light receiving surface is necessary based on the amount of light received, and a drive control unit that, when the judgment unit judges that cleaning is necessary, drives the moving means a number of cleanings corresponding to the amount of light received, thereby moving the cleaning member relatively back and forth between the retracted position and the cleaning position.

[0018] In order to achieve the object of the present invention, the cleaning method for a blade detection device of the present invention is a cleaning method for cleaning the light-projecting surface and light-receiving surface of a blade detection device having a light-projecting surface and a light-receiving surface arranged opposite each other with a blade sandwiched therebetween, and detecting the state of the blade based on the amount of light projected from the light-projecting surface and received via the light-receiving surface, the method comprising: a light-receiving amount detection step for detecting the amount of light received; a calculation step for calculating the rate of change of the amount of light received per unit time; a determination step for determining whether cleaning of the light-projecting surface and the light-receiving surface is necessary based on the amount of light received and the rate of change; and a moving step for relatively moving a cleaning member from a retracted position spaced apart from the light-projecting surface and the light-receiving surface to a cleaning position in which it comes into contact with the light-projecting surface and the light-receiving surface, the moving step being executed when the determination step determines that cleaning is necessary.

[0019] In order to achieve the object of the present invention, the cleaning method for a blade detection device of the present invention cleans the light-projecting surface and light-receiving surface of a blade detection device which has a light-projecting surface and a light-receiving surface arranged opposite each other with a blade sandwiched therebetween and which detects the state of the blade based on the amount of light projected from the light-projecting surface and received via the light-receiving surface, and includes: a light-receiving amount detection step of detecting the amount of received light; a determination step of determining whether cleaning of the light-projecting surface and the light-receiving surface is necessary based on the amount of received light; and a movement step of relatively moving a cleaning member back and forth between a retracted position spaced apart from the light-projecting surface and the light-receiving surface and a cleaning position in contact with the light-projecting surface and the light-receiving surface, and the movement step is performed a number of times for cleaning according to the amount of received light when the determination step determines that cleaning is necessary. [Effects of the Invention]

[0020] According to the present invention, the state of the blade can be detected accurately. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view of a dicing device equipped with a blade detection device according to an embodiment; [Figure 2] FIG. 2 is a perspective view showing the configuration of a processing unit of the dicing device shown in FIG. [Figure 3] 1 is a perspective view of a spindle provided with a detection unit and a feed mechanism; [Figure 4] FIG. 1 is a schematic structural diagram showing the structure of a detection unit of a cleaning member according to a first embodiment; [Figure 5] Schematic diagram showing the structure of the feed mechanism [Figure 6] FIG. 10 is an explanatory diagram illustrating a cleaning state using a cleaning member. [Figure 7] A perspective view of a cleaning member [Figure 8] Functional block diagram of a control unit that controls the operation of the cleaning member [Figure 9] Graph showing the amount of light received and the rate of change in the amount of light received [Figure 10] Flowchart of the first cleaning method [Figure 11] Graph showing the rate of change in the amount of light received [Figure 12] Flowchart of the second cleaning method [Figure 13] FIG. 10 is an explanatory diagram of a cleaning member according to a second embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a blade detection device and a method for cleaning a blade detection device according to the present invention will now be described in detail with reference to the accompanying drawings.

[0023] FIG. 1 is a perspective view showing the appearance of a dicing device 100 equipped with a blade detection device 10 (see FIG. 4) according to an embodiment.

[0024] 1 includes a processing unit 110 having a pair of spindles 106, 106 arranged opposite to each other and a work table 108 that suction-cleans the workpiece W. The dicing device 100 also includes a cleaning unit 112 that spin-cleans the processed workpiece W, a load port 114 on which a cassette containing a plurality of workpieces W is placed, a transport device 116 that transports the workpiece W, and a control unit 118 that controls the overall operation of each unit.

[0025] The spindle 106 is, for example, a spindle with a built-in high-frequency motor, and a blade 102 for cutting a workpiece W is attached to the tip of the spindle 106. The blade 102 is rotated by the spindle 106 at a high speed of, for example, 8000 rpm to 60000 rpm.

[0026] The blade 102 is a cutting blade formed in a thin disk shape. The blade 102 may be an electroplated blade in which diamond abrasive grains or CBN (Cubic Boron Nitride) abrasive grains are electrodeposited with nickel, or a resin blade bonded with resin. The dimensions of the blade 102 are selected according to the processing content, but when dicing a normal semiconductor wafer as the workpiece W, a blade with a diameter of about 50 mm and a thickness of about 30 μm is used.

[0027] FIG. 2 is a perspective view showing the configuration of the processing unit 110. As shown in FIG.

[0028] The processing unit 110 shown in Fig. 2 has an X table 126. This X table 126 is guided by X guides 122, 122 provided on an X base 120, and is driven in the X-axis direction indicated by XX in Fig. 2 by a linear motor 124. A rotary table 128 that rotates about the Z axis is mounted on this X table 126, and the work table 108 is mounted on this rotary table 128.

[0029] The processing unit 110 also has a Y base 130. This Y base 130 is arranged to straddle the linear motor 124. Y tables 134, 134 are provided on the side of this Y base 130, guided by Y guides 132, 132 and driven in the Y-axis direction indicated by YY in FIG. 2 by a drive unit (not shown). Each Y table 134 is provided with a Z table 136 that is driven in the Z-axis direction by a drive unit (not shown). The spindle 106, with the blade 102 attached to its tip, is fixed to the Z table 136. With this structure of the processing unit 110, the blade 102 is indexed in the Y-axis direction and cut in the Z-axis direction, while the work table 108 is cut in the X-axis direction. The X, Y, and Z axes are mutually orthogonal, with the X and Y axes oriented horizontally and the Z axis oriented vertically (up and down).

[0030] FIG. 3 is a perspective view showing the structure of the tip end of the spindle 106.

[0031] 3, a wheel cover 15 that covers the top of the blade 102 is attached to the tip of the spindle 106. This wheel cover 15 is constructed by assembling members such as a front cover portion 16, a rear cover portion 18, and a nozzle block 20, and has the function of suppressing the scattering of cutting powder, cutting water, and cooling water that are generated when the workpiece W is machined.

[0032] An end of a hose 21 is connected to the upper surface of the rear cover portion 18, and cutting water is supplied from the hose 21. The supplied cutting water is sprayed toward the rotating blade 102 from a nozzle 23 provided on the wheel cover 15. In addition, an end of a hose 22 is connected to the upper surface of the nozzle block 20, and cooling water is supplied from the hose 22. The supplied cooling water is sprayed toward the rotating blade 102 and workpiece W from a pair of L-shaped nozzles 24, 24 arranged opposite each other with the blade 102 in between.

[0033] The wheel cover 15 configured as described above is provided with the detection unit 12 that constitutes the blade detection device 10, and a feed mechanism 14 that moves the detection unit 12 in the Z-axis direction. The structure of the detection unit 12 will be described in detail below.

[0034] FIG. 4 is a schematic structural diagram showing the structure of the detection unit 12, and shows a side view of the detection unit 12 as seen from the X-axis direction in FIG.

[0035] 4, the detection unit 12 includes a light-projecting unit 26 and a light-receiving unit 28. The light-projecting unit 26 has a moving block 26A, and the light-receiving unit 28 has a moving block 28A. The moving blocks 26A and 28A are disposed opposite each other in the Y-axis direction and are connected to each other at their upper portions to form an integrated unit. A space 72 is formed between the moving blocks 26A and 28A along the Z-axis direction, and a cleaning member 70 (described later) is disposed in this space 72.

[0036] The light-projecting unit 26 has a light-emitting element 30 configured as a light-emitting diode, a laser diode, or the like, an optical cable 32 that transmits light from the light-emitting element 30, and a right-angle prism 34 that is attached to the lower part of the moving block 26A and reflects and emits the light transmitted by the optical cable 32. The light-emitting end face of the right-angle prism 34 is formed as a light-projecting surface 36 of the light-projecting unit 26. The light-projecting surface 36 is disposed at a distance from the side surface of the blade 102.

[0037] On the other hand, the light receiving unit 28 has a light receiving element 38 such as a photodiode, an optical cable 40 connected to the light receiving element 38, and a right-angle prism 42 attached to the lower part of the moving block 28A and connected to the optical cable 40. The light incident end face of the right-angle prism 42 is formed as a light receiving surface 44 of the light receiving unit 28.

[0038] In the blade detection device 10 shown in Figure 4, the light-projecting surface 36 of the light-projecting unit 26 and the light-receiving surface 44 of the light-receiving unit 28 are arranged opposite each other with the cutting edge 102A of the blade 102 sandwiched between them, and are configured so that of the light emitted (projected) from the light-projecting surface 36 toward the light-receiving surface 44, the light that is not blocked by the cutting edge 102A is incident on the light-receiving surface 44. Furthermore, based on the amount of light received by the light-receiving element 38, a control unit 118 (see Figure 1), which will be described later, detects the amount of wear on the blade 102 and performs cleaning using the cleaning member 70.

[0039] Next, the feed mechanism 14 that moves the detection unit 12 in the Z-axis direction will be described.

[0040] FIG. 5 is a schematic structural diagram showing the structure of the feed mechanism 14. As shown in FIG.

[0041] As shown in FIG. 5, the feed mechanism 14 includes a pulse motor 50, a gear 54 fixed to an output shaft 52 of the pulse motor 50, a gear 56 meshed with the gear 54, a feed screw 58 connected to the gear 56, and a nut 60 meshed with the feed screw 58 and fixed to the detection unit 12. The rotational axes of the output shaft 52 of the pulse motor 50, the gears 54 and 56, and the feed screw 58 are aligned along the Z-axis in FIG. 5. With the feed mechanism 14 configured in this manner, the rotational force of the pulse motor 50 is transmitted to the feed screw 58 via the gears 54 and 56, and the feed screw 58 is rotated, thereby moving the detection unit 12 along the Z-axis in FIG. 5 via the nut 60. As a result, the light-emitting surface 36 of the light-emitting unit 26 and the light-receiving surface 44 of the light-receiving unit 28 are moved integrally forward and backward relative to the rotation center S of the blade 102 (see FIG. 3).

[0042] According to the blade detection device 10 equipped with the detection unit 12 and the feed mechanism 14 described above, the control unit 118 (see FIG. 1) controls the feed mechanism 14 based on changes in the amount of light received by the light receiving element 38 to automatically feed the detection unit 12 in the Z-axis direction toward the rotation center S of the blade 102. The control unit 118 then integrates the amount of movement of the detection unit 12 to detect the amount of wear on the cutting edge 102A of the blade 102.

[0043] In the blade detection device 10 having the detection unit 12 described above, if dust generated during processing adheres to the light-projecting surface 36 of the detection unit 12, the light from the light-projecting surface 36 will be attenuated and scattered, lowering the signal-to-noise ratio and possibly resulting in erroneous detection of the state of the blade 102. Also, if dust adheres to the light-receiving surface 44, the amount of received light cannot be accurately detected, which may result in erroneous detection of the state of the blade 102.

[0044] Therefore, in order to prevent the above-mentioned erroneous detection, the blade detection device 10 of the embodiment is provided with a cleaning member 70 (see FIG. 4) that cleans (also called cleaning) the light-projecting surface 36 and the light-receiving surface 44. The cleaning member 70 will be described in detail below.

[0045] <Regarding the cleaning member 70 of the first embodiment> As shown in FIG. 4, the cleaning member 70 is disposed in a space 72 formed between the movable block 26A and the movable block 28A. When not cleaning, the cleaning member 70 is disposed in a retracted position indicated by the solid line in FIG. 4 and the two-dot chain line in FIG. 6. That is, the cleaning member 70 is disposed at a position spaced apart from the light-projecting surface 36 and the light-receiving surface 44. When cleaning the light-projecting surface 36 and the light-receiving surface 44, the cleaning member 70 is relatively moved from the retracted position to the cleaning position indicated by the solid line in FIG. 6 and comes into contact with the light-projecting surface 36 and the light-receiving surface 44. The cleaning member 70 is then relatively moved up and down in the Z-axis direction at the cleaning position. As a result, the light-projecting surface 36 and the light-receiving surface 44 are rubbed against the cleaning member 70, thereby removing dust adhering to the light-projecting surface 36 and the light-receiving surface 44. FIG. 6 is an explanatory diagram schematically illustrating the cleaning state of the light-projecting surface 36 and the light-receiving surface 44 by the cleaning member 70.

[0046] In the blade detection device 10 of this embodiment, the feed mechanism 14 that feeds and moves the detection unit 12 along the Z-axis direction also serves as a moving means for relatively moving the cleaning member 70 from the retracted position to the cleaning position.

[0047] When the feed mechanism 14 also serves as the moving means, the cleaning member 70 does not need to be moved, and is therefore preferably fixed to, for example, the wheel cover 15. The detection unit 12 in the state shown in FIG. 5 is then raised by the feed mechanism 14 to bring the light-emitting surface 36 and the light-receiving surface 44 into contact with the cleaning member 70. This allows the cleaning member 70 to be moved relative to the detection unit 12 to the cleaning position. The blade detection device 10 may also be provided with dedicated moving means for moving the cleaning member 70 independently between the cleaning position and the retracted position, without using the feed mechanism 14 as the moving means. In other words, any moving means that moves the detection unit 12 and the cleaning member 70 relative to each other between the cleaning position and the retracted position may be used as the moving means. However, using the feed mechanism 14 as the moving means is preferable because it simplifies the configuration of the blade detection device 10.

[0048] Next, the configuration of the cleaning member 70 for effectively removing dust adhering to the light-projecting surface 36 and the light-receiving surface 44 will be described.

[0049] <<About the material of the cleaning member 70>> The cleaning member 70 is preferably made of an elastic material that is elastically deformable, and one example of such a material is a sponge, which is a foam material.

[0050] <<Shape of the cleaning member 70>> FIG. 7 is a perspective view showing the appearance of the cleaning member 70. As shown in FIG.

[0051] 6 and 7, the cleaning member 70 is configured in a roll shape with a cylindrical cross section. The cleaning member 70 has an axis 70A and an outer peripheral surface 70B that functions as a cleaning surface. The cross section of the cleaning member 70 may be a perfect circle or, for example, an ellipse.

[0052] 6, by forming the cleaning member 70 into a roll shape, it becomes possible to effectively store the cleaning liquid 74 that cleans the light-projecting surface 36 and the light-receiving surface 44 in a gap 76 (a gap having a triangular cross section when viewed from the X-axis direction) between the outer peripheral surface 70B and the light-projecting surface 36, and in a gap 78 (a gap having a triangular cross section when viewed from the X-axis direction) between the outer peripheral surface 70B and the light-receiving surface 44. This improves the cleanability of the light-projecting surface 36 and the light-receiving surface 44.

[0053] The above-mentioned cleaning fluid 74 can be the cutting water or cooling water sprayed from the nozzles 23, 24, 24 (see FIG. 3). That is, the cutting water or cooling water splashes inside the wheel cover 15, and some of the splashed cutting water or cooling water accumulates in the above-mentioned gaps 76, 78 as cleaning fluid 74. Note that a supply line for individually supplying cleaning fluid 74 may be provided in the blade detection device 10. However, using the cutting water or cooling water as cleaning fluid 74 is preferable because it simplifies the device configuration of the blade detection device 10.

[0054] <<Regarding the arrangement of the cleaning member 70>> As shown in FIG. 6, the cleaning member 70 is disposed so that its axis 70A is aligned with the X-axis direction. When the cleaning member 70 is positioned at the cleaning position indicated by the solid line in FIG. 6, the cleaning member 70 is disposed at a central position between the light-projecting surface 36 and the light-receiving surface 44 in the Y-axis direction. This allows the outer peripheral surface 70B of the cleaning member 70 to contact the light-projecting surface 36 and the light-receiving surface 44 with a uniform contact force (pressure), thereby achieving uniform cleaning of the light-projecting surface 36 and the light-receiving surface 44. The cleaning member 70 can be fixed to the wheel cover 15 by supporting at least one of its longitudinal ends on the wheel cover 15. In this case, the cleaning member 70 may be supported rotatably or non-rotatably.

[0055] Fig. 8 is a functional block diagram of the control unit 118 that controls the cleaning operation of the cleaning member 70. Note that the control unit 118 controls the entire dicing apparatus 100, but in Fig. 8, to avoid complexity of the drawing, only the functional unit that controls the cleaning operation of the cleaning member 70 is shown.

[0056] 8, the control unit 118 includes a light-receiving-amount detecting unit 62 that detects the amount of light received by the light-receiving element 38 (see FIG. 4). The control unit 118 also includes a calculating unit 66 that calculates the rate of change in the amount of light received per unit time, a determining unit 65 that makes a determination based on the detection result of the light-receiving-amount detecting unit 62 and the calculation result of the calculating unit 66, and a drive control unit 64 that drives and controls the pulse motor 50 (see FIG. 5) of the feed mechanism 14. Based on the determination result by the determining unit 65, the drive control unit 64 drives and controls the pulse motor 50 to move the detection unit 12 along the Z axis.

[0057] The control unit 118 is configured to include one or more processors including a CPU (Central Processing Unit) and an FPGA (Field-Programmable Gate Array), and one or more memories.

[0058] Next, several examples of methods for cleaning the blade detection device 10 using the above-described cleaning member 70 will be described.

[0059] <First cleaning method> The first cleaning method is a cleaning method in which the determination unit 65 shown in FIG. 8 determines whether or not cleaning is necessary based on the "amount of received light" detected by the received light amount detection unit 62 and the "rate of change in the amount of received light" per unit time calculated by the calculation unit 66.

[0060] That is, the first cleaning method determines whether cleaning is necessary based not only on the "amount of received light" but also on the "rate of change in the amount of received light." The reason for this will be explained using the graph in FIG.

[0061] 9, the vertical axis represents the amount of light (L) detected by the received light amount detection unit 62, the horizontal axis represents the processing time (t), and the horizontal axis represents the amount of light received a as a contamination determination threshold. According to the graph indicated by IXA, it can be seen that the amount of light received detected by the received light amount detection unit 62 (see FIG. 8) tends to gradually decrease from the initial value immediately after the start of processing because dust and dirt adhering to the light-emitting surface 36 (see FIG. 7) and the light-receiving surface 44 increase over time.

[0062] Here, if the determination unit 65 determines whether cleaning is necessary based solely on the "amount of received light" shown in the graph IXA, for example, if the received light amount detection unit 62 detects a sudden drop in the amount of received light c that is less than the contamination determination threshold (amount of received light a), the determination unit 65 determines that cleaning is necessary and performs a cleaning operation on the cleaning member 70. However, the detection of the amount of received light c by the received light amount detection unit 62 is instantaneous, and the amount of received light immediately thereafter is equal to or greater than the amount of received light a. This phenomenon is thought to occur, for example, when fine dust particles block the optical path between the light-emitting surface 36 and the light-receiving surface 44. In this case, it is highly likely that the problem is not contamination, so cleaning is not necessary.

[0063] In other words, if the necessity of cleaning is determined based solely on the "amount of received light," there is a problem in that the cleaning operation of the cleaning member 70 may be carried out even when it is not actually necessary.

[0064] Therefore, in the first cleaning method, the judgment unit 65 determines whether cleaning is necessary based on the "amount of received light" detected by the received light amount detection unit 62 and the "rate of change in the amount of received light" calculated by the calculation unit 66, and cleaning is performed only when it is actually necessary.

[0065] Here, in the graph indicated by arrow IXB in Figure 9, the vertical axis shows the rate of change (dL / dt) of the amount of received light calculated by calculation unit 66, the horizontal axis shows the processing time (t), and the change rate range b as the dirt determination range is shown.

[0066] According to the graph IXB in Fig. 9, when the received light amount detecting unit 62 detects the above-mentioned received light amount c (t1), the "rate of change in received light" calculated by the calculating unit 66 is change rate e, which is outside the change rate range b, so at this time the determining unit 65 determines that cleaning is unnecessary as described above. Then, when the received light amount detecting unit 62 detects an "amount of received light" that is less than the received light amount a and the calculating unit 66 calculates a "rate of change in the amount of received light" that is within the change rate range b (t2), the determining unit 65 determines that cleaning is necessary and performs cleaning. In this way, the first cleaning method is one in which cleaning is performed only when it is essentially necessary.

[0067] The first cleaning method will be described below with reference to the flow chart shown in FIG. 10 and the graph in FIG.

[0068] As shown in FIG. 10, when processing by the blade 102 is started, the amount of received light is detected by the received light amount detection unit 62 (see FIG. 8) (S10: received light amount detection step).

[0069] Then, the judgment unit 65 (see FIG. 8) judges whether the amount of received light detected by the received light amount detection unit 62 is less than the amount of received light a (S20), and if the amount of received light is equal to or greater than the amount of received light a (S20: NO), it judges that cleaning is not necessary and returns to S10.

[0070] On the other hand, in S20, if the amount of received light detected by the received light amount detection unit 62 is the amount of received light c that is less than the amount of received light a (S20: YES), the determination unit 65 determines whether the rate of change in the amount of received light calculated by the calculation unit 66 is within the range of change rate b (S30: calculation step, determination step).If the rate of change is the above-mentioned rate of change e that is outside the range of change rate b (S30: NO, t1), it is determined that cleaning is not necessary and the process returns to S10 (determination step).

[0071] Then, if the amount of received light is less than the amount of received light a (S20: YES) and the rate of change is within the rate of change range b (S30: YES, t2), the determination unit 65 determines that cleaning is necessary (determination step). If the determination unit 65 determines that cleaning is necessary, the drive control unit 64 (see FIG. 8) drives the feed mechanism 14 to move the cleaning member 70 from the retracted position to the cleaning position, and the cleaning member 70 cleans the light-emitting surface 36 and the light-receiving surface 44 (S40: movement step). This completes the first cleaning method.

[0072] In the first cleaning method, as described above, when the "amount of received light" detected by the received light amount detection unit 62 is less than the amount of received light a and the "rate of change in the amount of received light" calculated by the calculation unit 66 is within the change rate range b, the cleaning member 70 is moved from the retracted position to the cleaning position and a cleaning operation is performed. In other words, even if the amount of received light is less than a, if it is not within the change rate range b, the change in the amount of received light is considered to be a temporary change not caused by dust or dirt adhering to the light-emitting surface 36 or the light-receiving surface 44, and therefore the cleaning operation is not performed. As a result, according to the first cleaning method, cleaning can be performed only when cleaning is actually necessary. This reduces wear on the cleaning member 70 and shortens the cleaning time, thereby improving the processing efficiency (throughput) of the workpiece W by the dicing apparatus 100.

[0073] Furthermore, in the first cleaning method, if it is determined that cleaning is necessary during the blade condition detection operation by the received light amount detection unit 62 or the like, the blade condition detection operation and processing operation can be temporarily stopped, and the cleaning member 70 can be moved to the cleaning position by the feed mechanism 14 to perform cleaning. This allows the blade condition detection operation and processing operation to be resumed quickly, and there is no need to stop the operation of the dicing apparatus 100 for the cleaning operation. Furthermore, since cleaning is performed by the cleaning member 70 when it is determined that cleaning is necessary as described above, it is possible to prevent erroneous detection due to dust and to accurately detect the condition of the blade 102.

[0074] <Second cleaning method> In the second cleaning method, the number of cleaning operations by the cleaning member 70 is changed depending on the “amount of received light” detected by the received light amount detection unit 62.

[0075] In other words, regardless of the "amount of received light," for example, if the number of cleanings by the cleaning member 70 is the same, there is a problem that even if the dirt is very small, it may be cleaned an excessive number of times that is not actually required, or even if the dirt is large, it may not be cleaned an excessive number of times that is actually required.

[0076] Therefore, the second cleaning method is to change the number of cleanings by the cleaning member 70 according to the "amount of received light" so as to perform cleaning the number of cleanings that is originally required.

[0077] The second cleaning method will be described below with reference to the flow chart shown in FIG. 12 and the graph shown in FIG.

[0078] 11, the vertical axis indicates the amount of received light (%) detected by the received light amount detection unit 62, and the horizontal axis indicates the processing time (t). The graphs XIA and XIB also indicate that the amount of received light (85%, for example) is set as the first threshold, and that the amount of received light (80%, for example) is set as the second threshold. Note that the amount of received light (%) in this example indicates the percentage when the amount of received light received by the light receiving unit 28 immediately after processing of the workpiece W begins is set as 100%, for example.

[0079] 12, in dicing apparatus 100 while processing workpiece W, a cleaning check command as to whether or not blade detection device 10 should be cleaned is periodically output from control unit 118 (see FIG. 8) to judgment unit 65 (S200). Upon receiving the cleaning check command, judgment unit 65 judges whether or not the amount of received light detected by received light amount detection unit 62 is equal to or greater than the first threshold amount of received light (85%) (S210), and if the amount of received light is equal to or greater than 85% (S210: YES), it judges it to be normal and ends cleaning without performing a cleaning operation (S220: received light amount detection step).

[0080] On the other hand, if the amount of received light detected by the received light amount detection unit 62 is less than 85% (S210: NO), the determination unit 65 determines whether the amount of received light is equal to or greater than the second threshold amount of received light (80%) (S230: received light amount detection step). If the amount of received light is equal to or greater than 80% (S230: YES), the determination unit 65 determines that cleaning is necessary and selects the maintenance mode (S240: determination step). In this maintenance mode, the drive control unit 64 controls the drive of the feeding mechanism 14 to clean the light-emitting surface 36 and the light-receiving surface 44 with the cleaning member 70 a first number of times (movement step).

[0081] Here, the number of cleaning cycles refers to the number of reciprocating movements (strokes) of the detection unit 12 by the feed mechanism 14, and in the maintenance mode, for example, one stroke of movement is performed.

[0082] XIA in FIG. 11 shows the change in the amount of received light when the maintenance mode is performed with one stroke. When the maintenance mode ends, the determination unit 65 determines whether the amount of received light detected by the received-light-amount detection unit 62 is 85% or greater (S250), as shown in FIG. 12. If the amount of received light is 85% or greater (S250: YES), the determination unit 65 determines that the operation is normal and terminates cleaning by the cleaning member 70 (S260). On the other hand, if the amount of received light after the maintenance mode ends is less than 85% (S250: NO), the determination unit 65 selects the forced cleaning mode (S270). In this forced cleaning mode, for example, the feed mechanism 14 causes the detection unit 12 to reciprocate multiple times to forcibly clean the light-emitting surface 36 and the light-receiving surface 44. Thereafter, the process returns to S210. In the forced cleaning mode, the cleaning member 70 may be rotated about the axis 70A to forcibly clean the light-emitting surface 36 and the light-receiving surface 44.

[0083] On the other hand, in S230, if the amount of received light detected by the received light amount detection unit 62 is less than 80% (S230: NO), the determination unit 65 determines that cleaning is necessary and selects the cleaning mode (S280: determination step). In this cleaning mode, the drive control unit 64 controls the drive of the feed mechanism 14 to clean the light-emitting surface 36 and the light-receiving surface 44 with the cleaning member 70 a second number of cleaning cycles (six strokes) that is greater than the first number of cleaning cycles (one stroke) (movement step).

[0084] 11 shows the change in the amount of received light when a cleaning mode with six strokes is performed. When this cleaning mode ends, the determination unit 65 determines whether the amount of received light detected by the received-light amount detection unit 62 is 85% or greater (S290), as shown in FIG. 12. If the amount of received light is 85% or greater (S290: YES), the determination unit 65 determines that the cleaning operation is normal and terminates cleaning by the cleaning member 70 (S300). On the other hand, if the amount of received light after the cleaning mode ends is less than 85% (S290: NO), the determination unit 65 selects the forced cleaning mode (S270) and causes the feed mechanism 14 to perform multiple reciprocating movements of the detection unit 12 to forcibly clean the light-emitting surface 36 and the light-receiving surface 44. Alternatively, the cleaning member 70 is rotated about the axis 70A to forcibly clean the light-emitting surface 36 and the light-receiving surface 44. Then, the process returns to S210. This completes the second cleaning method. The above-mentioned forced cleaning mode is a mode that forcibly removes relatively heavy dirt that could not be removed in the maintenance mode or cleaning mode, and the number of cleanings is set to be more than that in the cleaning mode (for example, about twice the number of cleanings in the cleaning mode).

[0085] In the second cleaning method, when the amount of received light detected by the received light amount detection unit 62 is less than a first threshold (e.g., 85%) and greater than or equal to a second threshold (e.g., 80%), cleaning is performed a first number of times, which is a smaller number of strokes. Furthermore, when the amount of received light is less than the second threshold, cleaning is performed a second number of times, which is a larger number of strokes. That is, when the amount of received light is greater than or equal to the first threshold, no cleaning operation is performed. When the amount of received light is less than the first threshold but greater than or equal to the second threshold, cleaning is performed a first number of times. Only when the amount of received light is less than the second threshold, cleaning is performed a second number of times. In this way, the second cleaning method performs cleaning operations an appropriate number of times corresponding to the degree of contamination on the light-emitting surface 36 and the light-receiving surface 44. This reduces wear on the cleaning member 70 and shortens the cleaning time, thereby improving the processing efficiency (throughput) of the workpiece W by the dicing apparatus 100.

[0086] Furthermore, in the second cleaning method, if it is determined that cleaning is necessary during the blade condition detection operation by the received light amount detection unit 62 or the like, the blade condition detection operation and processing operation are temporarily stopped, and the cleaning member 70 is moved back and forth between the retracted position and the cleaning position by the feed mechanism 14 to perform cleaning. This allows the blade condition detection operation and processing operation to be resumed quickly, and there is no need to stop the operation of the dicing apparatus 100 for the cleaning operation. Furthermore, because cleaning is performed by the cleaning member 70 when it is determined that cleaning is necessary as described above, erroneous detection due to dust can be prevented, and the condition of the blade 102 can be accurately detected.

[0087] In the second cleaning method described above, one stroke is used as the first cleaning count, but this is not limited to this. However, if the first cleaning count is increased more than necessary, the cleaning operation may be performed more than necessary, so it is preferable that the first cleaning count be approximately one or two strokes, as described above. Furthermore, six strokes is used as the second cleaning count, but this is not limited to this. However, if the second cleaning count is decreased more than necessary, the cleaning performance may be reduced, so it is preferable that the second cleaning count be approximately six or five strokes, as described above.

[0088] Furthermore, the first and second cleaning methods allow cleaning of the light-emitting surface 36 and the light-receiving surface 44 while the blade 102 is attached to the spindle 106, and therefore can further improve the processing efficiency of the workpiece W by the dicing device 100 compared to, for example, a cleaning method in which the blade 102 must be removed from the spindle 106 during cleaning.

[0089] Other embodiments of the cleaning member 70 will be described below.

[0090] <Regarding the cleaning member 70 of the second embodiment> The cleaning member 70 of the second embodiment will be described below with reference to Fig. 13. Note that parts that are the same as or similar to the cleaning member 70 of the first embodiment shown in Fig. 6 will be described with the same reference numerals.

[0091] The cleaning member 70 in the first embodiment is fixed to the wheel cover 15 side so as to be rotatable or non-rotatable, whereas the cleaning member 70 in the second embodiment shown in Figure 13 is rotatably mounted on the wheel cover 15 (see Figure 3) around an axis 70A.

[0092] 13, the cleaning member 70 is disposed at a position offset in the Y-axis direction closer to the light-projecting surface 36 than the light-receiving surface 44. The cleaning member 70 may be configured so that the amount of offset in the Y-axis direction is adjustable.

[0093] When the cleaning member 70 is positioned at an offset position as described above, the cleaning member 70 undergoes large elastic deformation when it comes into contact with the light-projecting surface 36 and small elastic deformation when it comes into contact with the light-receiving surface 44, so that the frictional resistance between the cleaning member 70 and the light-projecting surface 36 is set to be larger than the frictional resistance between the cleaning member 70 and the light-receiving surface 44.

[0094] In the cleaning member 70 of the second embodiment, when the detection unit 12 is raised by the feed mechanism 14 (see FIG. 5) and the light-emitting surface 36 and the light-receiving surface 44 are retracted upward from the cleaning member 70 as shown in FIG. 13, the difference in frictional resistance causes the cleaning member 70 to rotate a predetermined angle around the axis 70A in the direction of the arrow in FIG. 13.

[0095] As the cleaning member 70 rotates, a new portion of the outer peripheral surface 70B of the cleaning member 70 that was unused in the previous cleaning faces the light-projecting surface 36 and the light-receiving surface 44, and the new outer peripheral surface 70B can be used for the next cleaning. This allows the entire outer peripheral surface 70B of the cleaning member 70 to be used effectively, and also prevents uneven wear of the outer peripheral surface 70B, thereby extending the service life of the cleaning member 70. The same applies when the cleaning member 70 is positioned offset closer to the light-receiving surface 44 than the light-projecting surface 36.

[0096] Furthermore, in the second embodiment, the cleaning member 70 is rotatable about the central axis 70A, and the central axis 70A is disposed along the X-axis direction. However, this is not limiting. For example, the central axis 70A may be disposed at an angle with respect to the X-axis direction when viewed from the Y-axis direction. In this case, the cleaning member 70 rotates diagonally as the detection unit 12 moves up and down. This applies a lateral rubbing force from the cleaning member 70 to the light-emitting surface 36 and the light-receiving surface 44, thereby improving the cleaning power.

[0097] <Regarding the cleaning member 70 of the third embodiment> The cleaning member 70 of the third embodiment is mounted on the wheel cover 15 (see FIG. 3) so as to be slidable along the axis 70A. As a result, when the outer peripheral surface 70B of the cleaning member 70 becomes soiled during cleaning, the cleaning member 70 is slid along the axis 70A. This allows the unused, new outer peripheral surface 70B to be used for cleaning, thereby making effective use of the outer peripheral surface 70B of the cleaning member 70 and extending the service life of the cleaning member 70.

[0098] The cleaning member 70 of the first to third embodiments has been described above. As described above, the cleaning member 70 is made of an elastically deformable sponge, and therefore elastically and softly contacts the light-projecting surface 36 and the light-receiving surface 44 when cleaning the light-projecting surface 36 and the light-receiving surface 44. This prevents scratches on the light-projecting surface 36 and the light-receiving surface 44 and effectively removes dirt and dust adhering to the light-projecting surface 36 and the light-receiving surface 44. In this case, examples of the sponge include natural sponges and synthetic sponges. An example of a natural sponge is sea sponge. An example of a synthetic sponge is a foamed synthetic resin such as fluororubber or polyurethane. Among these, a foamed fluororubber sponge is preferred due to its high durability.

[0099] Furthermore, sponges with an open-cell structure, a semi-closed-cell structure, or a closed-cell structure can be used as the sponge. If the cleaning member 70 is a sponge with an open-cell structure, the cleaning liquid 74 can be stored inside the cleaning member 70, improving water retention. If the cleaning member 70 is a sponge with a semi-closed-cell structure, the water retention is improved and the ability to conform to the shape of the light-emitting surface 36 and the light-receiving surface 44 is improved. If the sponge is a closed-cell structure, the cleaning liquid 74 can be stored in the recesses in the outer peripheral surface 70B, improving water retention. Regardless of the type of sponge, the cleaning performance can be improved.

[0100] The cleaning member 70 is not limited to being made of sponge, and any elastic material that can be elastically deformed when it comes into contact with the light-emitting surface 36 and the light-receiving surface 44 can be used.

[0101] Furthermore, the cleaning member 70 is not limited to such an elastic member, and may be, for example, a member that is entirely made of resin such as plastic and is not elastically deformable.

[0102] Furthermore, in the first to third embodiments, the cleaning member 70 formed in a roll shape has been described, but the shape of the cleaning member is not limited to a roll shape, and may be, for example, spherical or brassy.

[0103] Furthermore, in the first to third embodiments, the configuration has been described in which one cleaning member 70 is used to clean both the light-projecting surface 36 and the light-receiving surface 44, but a cleaning member dedicated to the light-projecting surface and a cleaning member dedicated to the light-receiving surface may be provided, and the light-projecting surface 36 and the light-receiving surface 44 may be cleaned by the separate cleaning members. In this case, the dedicated cleaning members are not limited to being roll-shaped, but for example, when each cleaning member is configured in a roll shape, the axis of each may be arranged along the X-axis direction, or the axis of each may be arranged at an angle with respect to the X-axis direction as described above.

[0104] Furthermore, it is preferable to mount the blade detection device 10 described in this example on a dicing machine equipped with a device for automatically changing blades (see, for example, JP 2016-168652 A). This allows the cleaning member 70 of the blade detection device 10 to automatically perform the manual cleaning work that was previously performed by an operator when changing blades. This makes it possible to automate the entire blade changing process, including the cleaning work of the light-emitting surface 36 and the light-receiving surface 44.

[0105] Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and various modifications can be made without departing from the spirit of the present invention. [Explanation of symbols]

[0106] 10...blade detection device, 12...detection unit, 14...feed mechanism, 15...wheel cover, 16...front cover, 18...rear cover, 20...nozzle block, 21...hose, 22...hose, 23...nozzle, 24...nozzle, 26...light-emitting unit, 28...light-receiving unit, 30...light-emitting element, 32...optical cable, 34...right-angle prism, 36...light-emitting surface, 38...light-receiving element, 40...optical cable, 42...right-angle prism, 44...light-receiving surface, 50...pulse motor, 52...output shaft, 54...gear, 56...gear, 56...gear, 58...screw, 60...nail 62...received light amount detection unit, 64...drive control unit, 66...calculation unit, 70...cleaning member, 72...space, 74...cleaning liquid, 76...gap, 78...gap, 100...dicing device, 102...blade, 106...spindle, 108...work table, 110...processing unit, 112...cleaning unit, 114...load port, 116...transport device, 118...control unit, 120...X base, 122...X guide, 124...linear motor, 126...X table, 128...rotary table, 130...Y base, 132...Y guide, 134...Y table, 136...Z table

Claims

1. A blade detection device applicable to a dicing machine having a nozzle for spraying at least one of cutting water and cooling water onto at least one of a blade currently processing a workpiece and the workpiece, a detection unit having a light-projecting section having a light-projecting surface facing a side surface of the blade and a light-receiving section having a light-receiving surface facing the light-projecting surface across the blade, and capable of projecting light from the light-projecting surface toward the light-receiving surface while the workpiece is being machined by the blade; a cleaning member that uses at least one of the cutting water and the cooling water sprayed toward at least one of the blade and the workpiece as a cleaning liquid and comes into contact with the light-projecting surface and the light-receiving surface to clean the light-projecting surface and the light-receiving surface; a moving means for moving the cleaning member relative to the detection unit between a cleaning position in which the cleaning member contacts the light-emitting surface and the light-receiving surface and a retracted position spaced apart from the cleaning position.

2. a moving block having a space capable of accommodating the blade; The blade detection device according to claim 1 , wherein the light-emitting unit and the light-receiving unit are respectively disposed at two opposing tip portions on the opening side of the moving block.

3. a moving block having a space capable of accommodating the blade; The blade detection device according to claim 1 or 2, wherein the cleaning member is formed in a roll shape capable of storing the cleaning liquid between the cleaning member and the moving block.

Images