JP7521173B2 - Blade detection device and method for cleaning the blade detection device - Google Patents

Description

The present invention relates to a blade detection device and a method for cleaning the blade detection device, and in particular to a blade detection device that detects the condition of the blade of a dicing device, such as wear or damage, and a method for cleaning the blade detection device.

A dicing device that divides a workpiece on which semiconductor devices or electronic components are formed into individual chips is equipped with a blade that is rotated at high speed by a spindle and a table that suction-holds the workpiece. The dicing device performs grooving or cutting on the workpiece that is suction-held on the table with the blade that rotates at high speed.

In the above-mentioned dicing device, for example, the dicing device disclosed in Patent Document 1 is equipped with a blade detection device that detects the wear or damage of the blade.

The above blade detection device is attached to a wheel cover that covers the blade, and is equipped with a detection unit having a light-projecting section that projects light toward the blade, and a light-receiving section that is disposed opposite the light-projecting section across the blade and receives the light from the light-projecting section. The above blade detection device also has 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 wear of the blade by integrating the amount of movement.

JP 2009-231760 A

However, the above blade detection device is installed in a misty environment that contains cutting powder generated during workpiece processing, which causes the following problems:

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 section decreases. In this case, the blade detection device detects 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).

The present invention was made in consideration of these problems, and aims to provide a blade detection device and a method for cleaning the blade detection device that can accurately detect the condition of the blade.

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 spaced apart from the side of the blade, and a light-receiving section having a light-receiving surface arranged opposite the light-projecting surface across the blade, a detection unit that projects light from the light-projecting surface towards 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 apart from the light-projecting surface and the light-receiving surface, and a cleaning position where the cleaning member comes into contact with the light-projecting surface and the light-receiving surface.

One embodiment of the blade detection device of the present invention is preferably formed from an elastic member that can be elastically deformed.

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.

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.

In one embodiment of the blade detection device of the present invention, the cleaning member is provided so as to be freely rotatable about its axis, and when the cleaning member is in the cleaning position, it is preferable that the cleaning member is disposed at a position offset to the side closer to either the light projecting surface or the light receiving surface than the other.

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

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

One embodiment 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 projecting 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.

One embodiment 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 determination unit that determines whether cleaning of the light projecting surface and the light receiving surface is necessary based on the amount of light received, and a drive control unit that, when the determination unit determines that cleaning is necessary, drives the moving means for the number of cleanings corresponding to the amount of light received, thereby relatively moving the cleaning member back and forth between the retracted position and the cleaning position.

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 the light-receiving surface of a blade detection device that has a light-projecting surface and a light-receiving surface arranged opposite each other with a blade therebetween and detects the state of the blade based on the amount of light projected from the light-projecting surface and received through the light-receiving surface, the cleaning method includes a light-receiving amount detection process for detecting the amount of light received, a calculation process for calculating the rate of change in the amount of light received per unit time, a determination process 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 movement process 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 contact with the light-projecting surface and the light-receiving surface, the movement process being executed when the determination process determines that cleaning is necessary.

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 the light-receiving surface of a blade detection device that has a light-projecting surface and a light-receiving surface arranged opposite each other with a blade therebetween and detects the state of the blade based on the amount of light projected from the light-projecting surface and received through the light-receiving surface, the cleaning method includes a light-receiving amount detection process that detects the amount of light received, a determination process that determines whether cleaning of the light-projecting surface and the light-receiving surface is necessary based on the amount of light received, and a movement process that relatively moves the 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 process is performed a number of times for cleaning according to the amount of light received when the determination process determines that cleaning is necessary.

The present invention allows the blade condition to be detected accurately.

FIG. 1 is a perspective view of a dicing device equipped with a blade detection device according to an embodiment; FIG. 2 is a perspective view showing a configuration of a processing unit of the dicing device shown in FIG. FIG. 1 is a perspective view of a spindle provided with a detection unit and a feed mechanism; FIG. 1 is a schematic diagram showing a structure of a detection unit of a cleaning member according to a first embodiment; Schematic diagram showing the structure of the feed mechanism FIG. 1 is an explanatory diagram showing a schematic diagram of a cleaning state using a cleaning member; FIG. A functional block diagram of a control unit that controls the operation of the cleaning member. Graph showing the amount of light received and the rate of change in the amount of light received Flowchart of the first cleaning method Graph showing the rate of change in the amount of light received Flowchart of the second cleaning method FIG. 11 is an explanatory diagram of a cleaning member according to a second embodiment;

The following describes in detail a preferred embodiment of the blade detection device and the method for cleaning the blade detection device according to the present invention with reference to the attached drawings.

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

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

The spindle 106 is, for example, a spindle with a built-in high-frequency motor, and a blade 102 that performs cutting processing on a workpiece W is attached to the tip of the spindle 106. The blade 102 is rotated at high speed by the spindle 106, for example, at 8,000 rpm to 60,000 rpm.

The blade 102 is a cutting blade configured in a thin, disk-like shape. The blade 102 may be an electroplated blade in which diamond abrasive grains or CBN (Cubic Boron Nitride) abrasive grains are electroplated 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.

Figure 2 is a perspective view showing the configuration of the processing section 110.

The processing section 110 shown in FIG. 2 has an X-table 126. This X-table 126 is guided by X-guides 122, 122 provided on the X-base 120, and is driven in the X-axis direction indicated by X-X in FIG. 2 by a linear motor 124. This X-table 126 is equipped with a rotary table 128 that rotates around the Z-axis, and the work table 108 is provided on this rotary table 128.

The processing section 110 also has a Y base 130. This Y base 130 is provided so as to straddle the linear motor 124. On the side of this Y base 130, Y tables 134, 134 are provided, which are guided by Y guides 132, 132 and driven in the Y-axis direction indicated by Y-Y in FIG. 2 by a driving device (not shown). Each Y table 134 is provided with a Z table 136, which is driven in the Z-axis direction by a driving means (not shown). In addition, the spindle 106, which has the blade 102 attached to its tip, is fixed to the Z table 136. With this structure of the processing section 110, the blade 102 is index-fed in the Y-axis direction and cut-fed in the Z-axis direction, and the work table 108 is cut-fed in the X-axis direction. Note that the X, Y, and Z axes are mutually orthogonal, the X and Y axes are horizontal axes, and the Z axis is vertical (up and down) axis.

Figure 3 is an oblique view showing the tip structure of the spindle 106.

As shown in FIG. 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 components such as a front cover 16, a rear cover 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.

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

The wheel cover 15 configured as described above is provided with a 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.

Figure 4 is a schematic 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 Figure 3.

As shown in FIG. 4, the detection unit 12 includes a light-projecting section 26 and a light-receiving section 28. The light-projecting section 26 has a moving block 26A, and the light-receiving section 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 at their upper portions to be integrated. A space 72 is formed between the moving blocks 26A and 28A along the Z-axis direction, and a cleaning member 70, which will be described later, is disposed in this space 72.

The light-projecting unit 26 has a light-emitting element 30 composed of a light-emitting diode or a laser diode, an optical cable 32 that transmits the 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 the light-projecting surface 36 of the light-projecting unit 26. This light-projecting surface 36 is disposed at a distance from the side surface of the blade 102.

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 surface of the right-angle prism 42 is formed as the light receiving surface 44 of the light receiving unit 28.

In the blade detection device 10 shown in FIG. 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 to each other so as to sandwich the cutting edge 102A of the blade 102, 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. Based on the amount of light received by the light-receiving element 38, the control unit 118 (see FIG. 1), which will be described later, detects the amount of wear on the blade 102 and also performs cleaning using the cleaning member 70.

Next, we will explain the feed mechanism 14 that moves the detection unit 12 in the Z-axis direction.

Figure 5 is a schematic diagram showing the structure of the feed mechanism 14.

5, the feed mechanism 14 has a pulse motor 50, a gear 54 fixed to the 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 arranged along the Z axis in FIG. 5. According to the feed mechanism 14 configured in this way, 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, so that the detection unit 12 is moved 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 forward and backward together with respect to the rotation center S of the blade 102 (see FIG. 3).

According to the blade detection device 10 equipped with the above-mentioned detection unit 12 and feed mechanism 14, the control unit 118 (see FIG. 1) controls the feed mechanism 14 based on the change 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 detects the amount of wear on the cutting edge 102A of the blade 102 by integrating the amount of movement of the detection unit 12.

However, in the blade detection device 10 having the above-mentioned detection unit 12, 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 is attenuated and scattered, lowering the signal-to-noise ratio and may result in erroneous detection of the state of the blade 102. Also, if dust adheres to the light-receiving surface 44, the accurate amount of received light cannot be detected, and this may result in erroneous detection of the state of the blade 102.

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.

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 moving block 26A and the moving block 28A. When not cleaning, the cleaning member 70 is disposed in a retracted position indicated by a solid line in FIG. 4 and a two-dot chain line in FIG. 6. That is, the cleaning member 70 is disposed in 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 a cleaning position indicated by a solid line in FIG. 6 and contacts the light-projecting surface 36 and the light-receiving surface 44. The cleaning member 70 is 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, and dust attached to the light-projecting surface 36 and the light-receiving surface 44 is removed. FIG. 6 is an explanatory diagram that shows a schematic diagram of the cleaning state of the light-projecting surface 36 and the light-receiving surface 44 by the cleaning member 70.

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

When the feed mechanism 14 is used as a moving means, the cleaning member 70 does not need to be moved, so it is preferable to fix it to the wheel cover 15 side, for example. Then, the detection unit 12 in the state shown in FIG. 5 is raised by the feed mechanism 14 to bring the light projection surface 36 and the light receiving surface 44 into contact with the cleaning member 70. This makes it possible to move the cleaning member 70 to the above-mentioned cleaning position relative to the detection unit 12. Note that the blade detection device 10 may be provided with a dedicated moving means for moving the cleaning member 70 alone between the cleaning position and the retracted position without using the feed mechanism 14 as a moving means. In other words, the above-mentioned moving means can be any moving means that moves the detection unit 12 and the cleaning member 70 relatively between the cleaning position and the retracted position. However, it is preferable to use the feed mechanism 14 as a moving means because it simplifies the device configuration of the blade detection device 10.

Next, we will explain the configuration of the cleaning member 70 for effectively removing dust adhering to the light-projecting surface 36 and the light-receiving surface 44.

<<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.

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

As shown in Figures 6 and 7, the cleaning member 70 is configured in a roll shape with a cylindrical cross-sectional shape. This cleaning member 70 has an axis 70A and an outer peripheral surface 70B that functions as a cleaning surface. The cross-sectional shape of the cleaning member 70 may be a perfect circle or, for example, an ellipse.

By forming the cleaning member 70 into a roll shape, as shown in FIG. 6, the cleaning liquid 74 for cleaning the light-projecting surface 36 and the light-receiving surface 44 can be effectively stored in the gap 76 between the outer peripheral surface 70B and the light-projecting surface 36 (a gap with a triangular cross-section when viewed from the X-axis direction) and in the gap 78 between the outer peripheral surface 70B and the light-receiving surface 44 (a gap with a triangular cross-section when viewed from the X-axis direction). This improves the cleanability of the light-projecting surface 36 and the light-receiving surface 44.

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. A supply line for individually supplying cleaning fluid 74 may be provided in the blade detection device 10. However, it is preferable to use the cutting water or cooling water as cleaning fluid 74, since this simplifies the device configuration of the blade detection device 10.

Regarding the arrangement of the cleaning member 70
As shown in Fig. 6, the cleaning member 70 is disposed so that the axis 70A is along the X-axis direction. When the cleaning member 70 is at the cleaning position shown by the solid line in Fig. 6, the cleaning member 70 is disposed at the center 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 (pressing force), so that the cleaning properties of the light-projecting surface 36 and the light-receiving surface 44 can be made uniform. The cleaning member 70 can be fixed to the wheel cover 15 by supporting at least one of both ends in the longitudinal direction on the wheel cover 15 side. In this case, the cleaning member 70 may be supported rotatably or non-rotatably.

Figure 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 device 100, but in order to avoid cluttering the drawing, Figure 8 only illustrates the functional units that control the cleaning operation of the cleaning member 70.

As shown in FIG. 8, the control unit 118 includes a light-receiving amount detection 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 calculation unit 66 that calculates the rate of change in the amount of light received per unit time, a determination unit 65 that makes a determination based on the detection result of the light-receiving amount detection unit 62 and the calculation result of the calculation 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 determination unit 65, the drive control unit 64 drives and controls the pulse motor 50 to move the detection unit 12 along the Z axis.

The control unit 118 is configured with one or more processors, including a CPU (Central Processing Unit) and an FPGA (field-programmable gate array), and one or more memories.

Next, we will explain some examples of how to clean the blade detection device 10 using the above-mentioned cleaning member 70.

<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.

In other words, the first cleaning method determines whether or not 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 Figure 9.

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

Here, if the determination unit 65 determines whether cleaning is required based only on the "amount of received light" shown in the graph of IXA, for example, when the received light amount detection unit 62 detects a sudden drop in the amount of received light c that is less than the dirt determination threshold (amount of received light a), the determination unit 65 determines that cleaning is required, and the cleaning operation of the cleaning member 70 is performed. 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 blocks the optical path between the light projection surface 36 and the light receiving surface 44. In this case, it is highly likely that this is not dirt, so cleaning is not necessary.

In other words, if the need for 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 will be performed even when it is not actually necessary.

In the first cleaning method, the determination 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.

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

According to the graph of IXB in FIG. 9, when the received light amount detection unit 62 detects the above-mentioned received light amount c (t1), the "rate of change in received light" calculated by the calculation unit 66 is change rate e, which is outside the change rate range b, so at this time, the judgment unit 65 judges that cleaning is unnecessary as described above. Then, when the received light amount detection unit 62 detects an "amount of received light" less than the received light amount a and the calculation unit 66 calculates a "rate of change in the amount of received light" within the change rate range b (t2), the judgment unit 65 judges that cleaning is necessary and performs cleaning. In this way, the first cleaning method performs cleaning only when it is originally necessary.

The first cleaning method will now be described with reference to the graph in Figure 9 and the flowchart in Figure 10.

As shown in FIG. 10, when processing with the blade 102 begins, the amount of received light is detected by the received light amount detection unit 62 (see FIG. 8) (S10: received light amount detection process).

Then, the determination unit 65 (see FIG. 8) determines whether the amount of received light detected by the light receiving 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 determines that cleaning is not necessary and returns to S10.

On the other hand, in S20, if the amount of received light detected by the light receiving 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). Then, 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).

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 required (determination step). If the determination unit 65 determines that cleaning is required, 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 performs cleaning of the light projection surface 36 and the light receiving surface 44 with the cleaning member 70 (S40: movement step). This completes the first cleaning method.

In the first cleaning method, as described above, when the "amount of received light" detected by the light receiving 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 range of the rate of change b, the cleaning member 70 is moved from the retracted position to the cleaning position to perform the cleaning operation. In other words, even if the amount of received light is less than a, if it is not within the range of the rate of change b, it is considered to be a temporary change in the amount of received light that is not caused by dust or dirt adhering to the light projection surface 36 or the light receiving surface 44, so 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. Therefore, wear of the cleaning member 70 can be suppressed and the cleaning time can be shortened, so that the processing efficiency (throughput) of the workpiece W by the dicing device 100 can be improved.

Furthermore, in the first cleaning method, if cleaning is determined to be necessary during the blade state detection operation by the light receiving amount detection unit 62 or the like, the blade state 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 for cleaning. This allows the blade state detection operation and processing operation to be quickly resumed, and there is no need to stop the operation of the dicing device 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, erroneous detection due to dust can be prevented, and the state of the blade 102 can be accurately detected.

<Second cleaning method>
In the second cleaning method, the number of cleaning operations by the cleaning member 70 is changed according to the “amount of received light” detected by the received light amount detection unit 62 .

In other words, regardless of the "amount of received light," for example, if the number of cleanings using 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.

Therefore, the second cleaning method involves changing the number of cleanings performed by the cleaning member 70 depending on the "amount of received light," thereby performing cleaning the number of times that is originally required.

The second cleaning method will now be described with reference to the graph in Figure 11 and the flowchart in Figure 12.

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

As shown in FIG. 12, in the dicing device 100 during processing of the workpiece W, a cleaning check command as to whether or not to clean the blade detection device 10 is periodically output from the control unit 118 (see FIG. 8) to the judgment unit 65 (S200). The judgment unit 65 that has received the cleaning check command judges whether or not the amount of received light detected by the 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 the cleaning operation without performing the cleaning operation (S220: received light amount detection process).

On the other hand, in S210, if the amount of received light detected by the light receiving amount detection unit 62 is less than 85% (S210: NO), the judgment unit 65 judges whether the amount of received light is equal to or greater than the second threshold amount of received light (80%) (S230: light receiving amount detection process). Then, if the amount of received light is equal to or greater than 80% (S230: YES), the judgment unit 65 judges that cleaning is necessary and selects the maintenance mode (S240: judgment process). In this maintenance mode, the drive control unit 64 drives and controls the feed mechanism 14 to clean the light projection surface 36 and the light receiving surface 44 with the cleaning member 70 for the first cleaning number of times (movement process).

The number of cleanings mentioned above 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 operation is performed.

In FIG. 11, XIA shows the change in the amount of received light when the maintenance mode is executed with one stroke. When the maintenance mode ends, the determination unit 65 determines whether the amount of received light detected by the light-receiving amount detection unit 62 is 85% or more (S250), as shown in FIG. 12, and if the amount of received light is 85% or more (S250: YES), it determines that the operation is normal and ends the 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 reciprocating movement of the detection unit 12 by the feed mechanism 14 is executed multiple times to forcibly clean the light-projecting surface 36 and the light-receiving surface 44. Then, the process returns to S210. In the forced cleaning mode, the cleaning member 70 may be rotated around the axis 70A to forcibly clean the light-projecting surface 36 and the light-receiving surface 44.

On the other hand, in S230, if the amount of received light detected by the light receiving 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 drives and controls the feed mechanism 14 to clean the light projecting surface 36 and the light receiving surface 44 with the cleaning member 70 a second number of cleaning cycles (6 strokes) that is greater than the first number of cleaning cycles (1 stroke) (movement step).

In FIG. 11, XIB shows the change in the amount of received light when the cleaning mode with six strokes is executed. When such a cleaning mode ends, the determination unit 65 determines whether the amount of received light detected by the light-receiving amount detection unit 62 is 85% or more (S290), as shown in FIG. 12, and if the amount of received light is 85% or more (S290: YES), it determines that the cleaning is normal and ends the 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 executes the reciprocating movement of the detection unit 12 by the feed mechanism 14 multiple times to forcibly clean the light-projecting surface 36 and the light-receiving surface 44. Or, the cleaning member 70 is rotated around the axis 70A to forcibly clean the light-projecting surface 36 and the light-receiving surface 44. Then, the process returns to S210. This is the second cleaning method. The forced cleaning mode is a mode that forcibly removes relatively heavy dirt that could not be removed by the maintenance mode or cleaning mode, and the number of cleanings is set to be more than in the cleaning mode (for example, about twice the number of cleanings in the cleaning mode).

In the second cleaning method described above, when the amount of received light detected by the light receiving amount detection unit 62 is less than the first threshold (e.g., 85%) and is equal to or greater than the second threshold (e.g., 80%), cleaning is performed for the first cleaning number, which is the smaller number of strokes. Also, when the amount of received light is less than the second threshold, cleaning is performed for the second cleaning number, which is the larger number of strokes. That is, when the amount of received light is equal to or greater than the first threshold, cleaning is performed for the first cleaning number, when the amount of received light is less than the first threshold but is equal to or greater than the second threshold, cleaning is performed for the second cleaning number only when the amount of received light is less than the second threshold. In this way, the second cleaning method performs the cleaning operation with an appropriate number of cleanings corresponding to the degree of dirt attached to the light projecting surface 36 and the light receiving surface 44, so that wear of the cleaning member 70 can be suppressed and the cleaning time can be shortened, thereby improving the processing efficiency (throughput) of the workpiece W by the dicing device 100.

In addition, in the second cleaning method, when cleaning is determined to be necessary during the blade state detection operation by the light receiving amount detection unit 62 or the like, the blade state 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 state detection operation and processing operation to be quickly resumed, and there is no need to stop the operation of the dicing device 100 for the cleaning operation. In addition, since 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 state of the blade 102 can be accurately detected.

In the above second cleaning method, one stroke is exemplified 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 as described above, it is preferable that the first cleaning count is about one or two strokes. Also, six strokes are exemplified 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 decrease, so as described above, it is preferable that the second cleaning count is about six or five strokes.

In addition, the first and second cleaning methods allow cleaning of the light-projecting 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.

Other embodiments of the cleaning member 70 are described below.

<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.

The cleaning member 70 in the first embodiment is fixed to the wheel cover 15 in a rotatable or non-rotatable manner, whereas the cleaning member 70 in the second embodiment shown in FIG. 13 is rotatably mounted on the wheel cover 15 (see FIG. 3) around the axis 70A.

In addition, in the second embodiment of the cleaning member 70, when the cleaning member 70 is located at the cleaning position shown by the two-dot chain line in FIG. 13, the cleaning member 70 is positioned at a position offset in the Y-axis direction closer to the light projection surface 36 than the light receiving surface 44. Note that the cleaning member 70 may be configured so that the amount of offset in the Y-axis direction is freely adjustable.

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.

In this second embodiment of the cleaning member 70, when the detection unit 12 is raised by the feed mechanism 14 (see FIG. 5) and the light-projecting 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.

By rotating the cleaning member 70, the new 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, so that 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.

In addition, in the second embodiment of the cleaning member 70, the cleaning member 70 is rotatable about the axis 70A and is arranged along the X-axis direction, but this is not limited to the above. For example, when viewed from the Y-axis direction, the axis 70A may be arranged at an angle to the X-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-projecting surface 36 and the light-receiving surface 44, improving the cleaning power.

<Regarding the cleaning member 70 of the third embodiment>
The cleaning member 70 of the third embodiment is provided 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 dirty due to the cleaning operation, the cleaning member 70 is slid along the axis 70A. As a result, the unused new outer peripheral surface 70B can be used for cleaning, so that the outer peripheral surface 70B of the cleaning member 70 can be effectively used and the service life of the cleaning member 70 can be extended.

The above describes the cleaning member 70 of the first to third embodiments. As described above, the cleaning member 70 is made of an elastically deformable sponge, so that when cleaning the light-projecting surface 36 and the light-receiving surface 44, the cleaning member 70 elastically and softly contacts the light-projecting surface 36 and the light-receiving surface 44. This makes it possible to prevent scratches on the light-projecting surface 36 and the light-receiving surface 44, and to effectively remove 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 sponge and synthetic sponge. An example of a natural sponge is sea sponge. Also, examples of a synthetic sponge include foamed synthetic resins such as fluororubber or polyurethane. Among these, sponges foamed with fluororubber are preferred because of their high durability.

The sponge may have an open cell structure, a semi-closed cell structure, or a closed cell structure. 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 conformability to the shape of the light-projecting surface 36 and the light-receiving surface 44 is improved. If the sponge has a closed cell structure, the cleaning liquid 74 can be stored in the recesses of the outer peripheral surface 70B, improving water retention. Regardless of the type of sponge, the cleaning ability can be improved.

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

In addition, the cleaning member 70 is not limited to such elastic members, and may be, for example, a member that is entirely made of resin such as plastic and is not elastically deformable.

In addition, 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.

In the first to third embodiments, the light-projecting surface 36 and the light-receiving surface 44 are cleaned by a single cleaning member 70. However, 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 separate cleaning members. In this case, the dedicated cleaning members are not limited to those in a roll shape. For example, when each cleaning member is configured in a roll shape, each axis may be arranged along the X-axis direction, or each axis may be arranged at an angle with respect to the X-axis direction as described above.

Furthermore, it is preferable to mount the blade detection device 10 described in this example on a dicing device 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 is performed by an operator when changing blades. Therefore, it is possible to automate a series of blade changing operations, including the cleaning work of the light projection surface 36 and the light receiving surface 44.

Although an embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and various modifications are possible without departing from the spirit of the invention.

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 projecting section, 28...Light receiving section, 30...Light emitting element, 32...Optical cable, 34...Right-angle prism, 36...Light projecting 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...Nut , 62...light receiving 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 (13)

A blade detection device capable of detecting a state of a blade during processing of a workpiece,
a moving block having a space that opens to the workpiece side and capable of housing the blade in the space from the opening side;
a detection unit including a light-projecting section having a light-projecting surface disposed at the tip of the moving block on the work side, and a light-receiving section having a light-receiving surface disposed opposite the light-projecting surface across the space , the detection unit projecting 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 the light projecting surface and the light receiving surface;
a moving means for relatively moving the detection unit and the cleaning member between a cleaning position in the space where the cleaning member contacts the light projection surface and the light receiving surface and a retracted position spaced from the cleaning position in a direction opposite to the opening side,
Blade detection device. The cleaning member is formed of an elastic member that is elastically deformable.
The blade detection device of claim 1 . The cleaning member is a sponge having an open cell structure, a semi-closed cell structure, or a closed cell structure.
3. The blade detection device of claim 2. The cleaning member is formed in a roll shape having an axis capable of storing cleaning liquid in a gap between the cleaning member and the moving block .
A blade detection device according to any one of claims 1 to 3. The cleaning member is provided so as to be rotatable about the axis,
When the cleaning member is in the cleaning position, the cleaning member is disposed at a position offset toward a side closer to either the light projection surface or the light receiving surface than the other.
5. The blade detection device of claim 4. The cleaning member is disposed slidably along the axis.
A blade detection device according to claim 4 or 5. a feed means for driving the detection unit toward the rotation center of the blade;
The feeding means is also used as the moving means.
A blade detection device according to any one of claims 1 to 6. a light receiving amount detection unit that detects an amount of light received by the light receiving unit;
A calculation unit that calculates a rate of change of the amount of received light per unit time;
a determination unit that determines whether or not cleaning of the light projection surface and the light receiving surface is necessary based on the amount of received light and the rate of change;
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 the cleaning is necessary,
A blade detection device according to any one of claims 1 to 7. a light receiving amount detection unit that detects an amount of light received by the light receiving unit;
a determination unit that determines whether or not cleaning of the light projection surface and the light receiving surface is required based on the amount of received light;
a drive control unit that drives the moving means to relatively move the cleaning member back and forth between the retracted position and the cleaning position by a number of cleaning times corresponding to the amount of received light when the determination unit determines that cleaning is necessary,
A blade detection device according to any one of claims 1 to 7. The blade detection device according to claim 9 , wherein the determination section determines that the detection unit is capable of normal detection when determining that the amount of received light is equal to or greater than a threshold value after cleaning. A cleaning method for cleaning a blade detection device having a light-projecting surface and a light-receiving surface disposed opposite each other with a blade therebetween, the blade detection device detecting a state of the blade based on an amount of light projected from the light-projecting surface and received via the light-receiving surface, comprising:
a light receiving amount detection step of detecting the amount of light received;
a calculation step of calculating a rate of change of the amount of received light per unit time;
a determination step of determining whether or not cleaning of the light projection surface and the light receiving surface is necessary based on the amount of received light and the rate of change;
a moving step of relatively moving a cleaning member from a retreated position separated from the light projection surface and the light receiving surface to a cleaning position in which the cleaning member contacts the light projection surface and the light receiving surface,
The moving step is performed when the determining step determines that the cleaning is necessary.
A method for cleaning a blade detection device. A cleaning method for cleaning a blade detection device having a light-projecting surface and a light-receiving surface disposed opposite each other with a blade therebetween, the blade detection device detecting a state of the blade based on an amount of light projected from the light-projecting surface and received via the light-receiving surface, comprising:
a light receiving amount detection step of detecting the amount of light received;
a determination step of determining whether or not cleaning of the light projection surface and the light receiving surface is necessary based on the amount of received light;
a moving step of relatively reciprocatingly moving a cleaning member between a retracted position spaced apart from the light projection surface and the light receiving surface and a cleaning position in contact with the light projection surface and the light receiving surface,
the moving step is performed a number of times for cleaning corresponding to the amount of received light when the determining step determines that cleaning is necessary.
A method for cleaning a blade detection device. a detection unit including a light-projecting section having a light-projecting surface disposed at a distance from a side surface of the blade, and a light-receiving section having a light-receiving surface disposed opposite the light-projecting surface across the blade, the detection unit projecting 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 the light projecting surface and the light receiving surface;
a moving means for relatively moving the detection unit and the cleaning member between a retracted position where the cleaning member is separated from the light projection surface and the light receiving surface and a cleaning position where the cleaning member is in contact with the light projection surface and the light receiving surface,
A blade detection device in which the cleaning member is formed in a roll shape having an axis, is freely rotatable around the axis, and is positioned at a position offset to one side closer to the other of the light projecting surface and the light receiving surface when in the cleaning position.

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