JP6860416B2 - Processing equipment - Google Patents

Description

The present invention relates to a processing apparatus capable of measuring the surface state of a processing surface of a processing tool.

The polishing device polishes the workpiece with a polishing pad containing abrasive grains. A polishing pad formed by increasing the amount of abrasive grains contained in the polishing pad is brittle and easily chipped. Therefore, if there is a chipping, a locus is formed on the surface to be polished of the work piece, which may result in poor polishing. .. Therefore, it is necessary to confirm whether or not the processed surface (polished surface) of the polishing pad is chipped. Further, the grinding device may use a grinding wheel in which a grinding wheel containing many small abrasive grains is arranged in order to finish the work surface of the work piece to a mirror surface, but this grinding wheel is a grindstone more than before. The amount of bond that hardens the grains is small and chipping is likely to occur. In this case as well, as with the polishing device, if a chip occurs, a locus of the grinding wheel is formed on the surface to be ground, which may result in grinding failure. Therefore, whether the machined surface (ground surface) of the grinding wheel is chipped. (For example, see Patent Document 1 below).

Apart from chipping, grinding debris generated when the workpiece is ground may adhere to the grinding surface of the grinding wheel, clogging the grinding surface and reducing the grinding force. When the workpiece is, for example, a silicon wafer provided with a metal electrode, if the silicon wafer is ground with a grinding wheel to scrape the metal electrode, the metal enters the ground surface and clogging is likely to occur. Therefore, in order to prevent clogging of the ground surface, there is a grinding device that regularly dresses (see, for example, Patent Document 2 below). Further, also in the polishing process of the work piece, since the polishing debris gets into the polishing surface of the polishing pad and causes clogging, dressing is performed regularly.

Japanese Unexamined Patent Publication No. 2016-78147 Japanese Unexamined Patent Publication No. 2011-189456

As described above, if dressing is performed regularly, clogging of the processed surface of the processing tool can be eliminated, but dressing increases the consumption of the polishing pad and the grinding wheel. That is, excessive dressing shortens the life of the polishing pad and the grinding wheel, resulting in an increase in the replacement work of the polishing pad and the grinding wheel.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent excessive dressing, stabilize the processing quality of the workpiece, and reduce the consumption of the processing tool. There is.

The present invention comprises a holding table for holding a work piece, a processing means having a rotating means for rotating by attaching a processing tool for grinding or polishing the work piece held by the holding table, and holding the processing means. A processing apparatus including a moving means for moving in a direction of approaching and separating from a table, an imaging means for imaging the processing surface from a direction perpendicular to the processing surface of the processing tool, and the imaging means. The processing tool is provided with an advancing / retreating means for entering an imaging position capable of imaging the processed surface or retracting the imaging means to a retracted position away from the imaging position, and the processing tool is provided with a plurality of segment grindstones in an annular shape. A grinding wheel or a polishing pad in which a plurality of segment polishing pads are arranged in an annular shape is provided, and the imaging means is the segmented grindstone arranged in an annular shape or the processed surface of the segment polishing pad arranged in an annular shape. A line sensor extending in the radial direction at the radius of the line sensor and imaging from a direction perpendicular to the machined surface, and a line sensor extending in parallel with the line sensor and arranged in the vicinity of the line sensor to the machined surface. A first illumination that irradiates light from a position near the line sensor, and a second illumination that is arranged away from the position of the line sensor in the outer peripheral tangential direction of the machined surface and irradiates light obliquely to the machined surface. The illumination image, the switching means for switching between the first illumination and the second illumination, and the imaging image obtained by switching between the first illumination and the second illumination and imaging the processed surface by the imaging means. It is provided with a determination means for determining whether or not the machined surface can continue to be machined.

Further, in the present invention, the processing surface is imaged by the imaging means while illuminating the processing surface with the first illumination switched by the switching means while rotating the processing tool, and the determination means is an object to be processed. The number of brightly shining parts for each of the segment grindstones or the segment polishing pads is equal to or greater than a preset number, or the segment grindstones or the segment polishing pads are used. If the total area of the brightly shining parts is equal to or larger than the preset area, it is determined that the machined surface is abnormal, and the number of brightly shining parts is preset for each segment grindstone or the segment polishing pad. It is preferable to include a second determination unit for determining that the machined surface is normal if the area is less than the number or the total area of the brightly shining portions is smaller than the preset area.

Further, in the present invention, the processing surface is imaged by the imaging means while illuminating the processing surface with the second illumination switched by the switching means while rotating the processing tool, and the determination means is chipped. A storage unit that stores an image of the processed surface of the segment grindstone or the segment polishing pad that has not been processed, and the processing after processing the image and the workpiece stored in the storage unit with the processing tool. It is preferable to provide a first determination unit that requests replacement of the grinding wheel or the polishing pad if the shapes match with each other and the processing is continued if the shapes match. ..

According to the present invention, an imaging means for imaging a processing surface from a direction perpendicular to the processing surface of the processing tool, and an imaging means entering an imaging position where the processing surface can be imaged or retracting the imaging means to a retracted position away from the imaging position The processing tool includes a grinding wheel in which a plurality of segment grindstones are arranged in an annular shape or a polishing pad in which a plurality of segment polishing pads are arranged in an annular shape, and the imaging means is arranged in an annular shape. A line sensor that extends radially in the radius of the machined surface of the segmented grindstone or segment polishing pad arranged in an annular shape and images from a direction perpendicular to the machined surface, and a line that extends parallel to the line sensor. The first illumination, which is arranged near the sensor and irradiates the machined surface with light from a position near the line sensor, and the machined surface, which is arranged away from the position of the line sensor in the outer peripheral tangential direction of the machined surface. A second illumination that irradiates light from an oblique angle, a switching means for switching between the first illumination and the second illumination, and a switching means for switching between the first illumination and the second illumination to image the processed surface by the imaging means. Since the image is provided with a means for determining whether or not the machined surface can continue to be machined, the surface condition of the machined surface of the machining tool can be confirmed, and excessive dressing can be prevented. Tool wear can be reduced. As a result, the life of the processing tool is extended, and the frequency of replacement of the processing tool can be reduced. Further, according to the present invention, since the surface condition of the processed surface of the processing tool can be observed by using the image pickup image, the processed surface is in a state of adversely affecting the processing, or the processed surface is in a state where the processing can be continued. Since it can be determined whether or not the work piece is processed, it is possible to prevent processing defects of the workpiece.

Further, in the present invention, the processing surface is imaged by the imaging means while illuminating the processing surface with the first illumination switched by the switching means while rotating the processing tool, and the determination means processes the workpiece. The number of brightly shining parts for each of the segment grindstones or the segment polishing pads is equal to or greater than a preset number, or the brightly shining parts for each segment grindstone or the segment polishing pad, using an image of the processed surface of the processing tool. If the total area of the above is equal to or greater than the preset area, it is judged that the machined surface is abnormal, and the number of brightly shining parts for each segment grindstone or segment polishing pad is less than the preset number or shines brightly. Since it is equipped with a second judgment unit that determines that the machined surface is normal if the total area of the parts is smaller than the preset area, the number of brightly shining parts and the number of brightly shining parts by analyzing the captured image are provided. The area can be calculated to check the surface condition of the machined surface, and it is possible to detect how much foreign matter is attached to the machined surface.

Further, in the present invention, the processing surface is imaged by the imaging means while illuminating the processing surface with the second illumination switched by the switching means while rotating the processing tool, and the determination means is chipped. A storage unit that stores an image of the processed surface of the segment grindstone or the segment polishing pad that has not been processed, and the processing after processing the image and the workpiece stored in the storage unit with the processing tool. Compared with the image taken by imaging the surface, if the shapes match, the processing is continued, and if the shapes do not match, the grinding wheel or the polishing pad is requested to be replaced. The image can be analyzed to see if the segment grindstone or the segment polishing pad is chipped.

It is a perspective view which shows the structure of the 1st example of a processing apparatus. It is sectional drawing which shows the structure of the polishing pad. It is a bottom view which shows the structure of a polishing pad. FIG. 5 is a cross-sectional view showing a state in which the imaging means is positioned at the imaging position while explaining the configuration of the imaging means. It is sectional drawing which shows the state which image | photographed the processed surface of the segment polishing pad by the imaging means. This is an image of the processed surface of the segment polishing pad in which no chipping has occurred. This is an image taken by an imaging means while illuminating the processed surface of the segment polishing pad after processing the workpiece with the second illumination. It is a perspective view which shows the structure of the 2nd example of a processing apparatus. It is a bottom view which shows the structure of a grinding wheel. It is sectional drawing which shows the state which image | photographed the machined surface of the segment grindstone by the imaging means. This is an image taken by an imaging means while illuminating the processed surface of the segment grindstone after processing the workpiece with the first illumination. This is an image taken by an imaging means while illuminating the processed surface of the segment grindstone after processing the workpiece with the second illumination.

1 First example of processing apparatus The processing apparatus 1 shown in FIG. 1 is an example of a processing apparatus that performs dry polishing (dry polishing) on a work piece, and includes an apparatus base 1a extending in the Y-axis direction and an apparatus. It has a column 1b erected on the rear side of the base 1a in the Y-axis direction. A holding table 2 for holding a work piece is arranged on the upper surface of the device base 1a. The upper surface of the holding table 2 is a holding surface 2a that sucks and holds the work piece. Below the holding table 2, a machining feeding means (not shown) for machining and feeding the holding table 2 in the horizontal direction (Y-axis direction) is arranged.

In front of the column 1b, a processing means 3 having a rotating means for rotating by mounting a processing tool for polishing the workpiece held by the holding table 2 and the processing means 3 approach and separate from the holding table 2. It is provided with a moving means 4 for moving in a direction (Z-axis direction). The moving means 4 includes a ball screw 40 extending in the Z-axis direction, a motor 41 connected to one end of the ball screw 40, a pair of guide rails 42 extending parallel to the ball screw 40, and one surface of the processing means 3 It is provided with an elevating plate 43 fixed to the base. The other surface of the elevating plate 43 is in sliding contact with the pair of guide rails 42, and the ball screw 40 is screwed into the nut formed inside the elevating plate 43. By rotating the ball screw 40 by the motor 41, the processing means 3 can be moved in the Z-axis direction together with the elevating plate 43.

The processing means 3 includes a spindle 30 having an axis in the vertical direction (Z-axis direction), a spindle housing 31 that rotatably surrounds the spindle 30, and a spindle 30 connected to one end of the spindle 30 so as to have the axis in the vertical direction. A motor 32 that is a rotating means for rotating as a center, a holder 33 that holds the spindle housing 31, a mounter 34 mounted on the lower end of the spindle 30, and a processing tool that is detachably mounted on the lower surface of the mounter 34. It is provided with a pad 35. Although not shown, the motor 32 is connected to a rotary encoder for detecting the rotation origin and the rotation angle of the spindle 30. Then, the motor 32 rotates the spindle 30, so that the polishing pad 35 can be rotated at a predetermined rotation speed.

As shown in FIG. 2, the mounter 34 is formed in a disk shape, for example. The lower surface of the mounter 34 is a free end 34a on which the polishing pad 35 is mounted, and the free end 34a is a flat surface parallel to the horizontal direction orthogonal to the vertical direction. A plurality of mounting holes 360 into which bolts 38 for fastening the polishing pad 35 are inserted are formed in the mounter 34 at equal intervals in the circumferential direction. The mounting hole 360 is formed so as to penetrate the upper and lower surfaces of the mounter 34.

The polishing pad 35 includes a disc-shaped base 36 and a plurality of segment polishing pads 37 adhered to the mounting surface 36a of the base 36. The mounting surface 36a of the base 36 is formed on a flat surface parallel to the upper surface of the segment polishing pad 37. A plurality of female screw holes 340 into which bolts 38 are screwed are formed on the mounting surface 36a. A plurality of female screw holes 340 are formed at equal intervals in the circumferential direction corresponding to the positions of the plurality of mounting holes 360 formed in the mounter 34.

The segment polishing pad 37 is made of, for example, urethane or a non-woven fabric. As shown in FIG. 3, the segment polishing pad 37 has a width that expands from the rotation center O side of the polishing pad 35 toward the center in the radial direction and decreases from the center toward the outer circumference, and has petals. It is formed like the shape of. The polishing pad 35 is provided with equal angles in the circumferential direction about the rotation center O of the polishing pad 35, and for example, five segment polishing pads 37 are arranged adjacent to each other on the base 36 in an annular shape. There is. The lower surface of each segment polishing pad 37 arranged in an annular shape on the base 36 is a processed surface 37a for polishing the workpiece. The outer diameter of the polishing pad 35 configured in this way is set to be substantially the same as the outer diameter of the mounter 34 shown in FIG. 2, for example, φ450 mm. The outer diameter of the polishing pad 35 and the shape and number of the segment polishing pads 37 shown in the present embodiment are only one aspect and can be changed as appropriate.

The processing apparatus 1 shown in FIG. 1 has an imaging means 10 that images the processing surface 37a from a direction perpendicular to the processing surface 37a of the segment polishing pad 37, and the imaging means 10 enters or enters an imaging position where the processing surface 37a can be imaged. It is provided with advancing / retreating means 20 for retracting the imaging means 10 to a retracting position away from the imaging position. The advancing / retreating means 20 is attached to a shaft member 21 extending in the Z-axis direction, an arm 22 connected to the upper end of the shaft member 21 and extending in a direction orthogonal to the extending direction of the shaft member 21, and a lower end of the shaft member 21. It includes a motor 23 that is connected and rotates the shaft member 21. In the example of FIG. 1, the imaging means 10 is mounted on the arm 22. The imaging position may be any position as long as the processed surface 37a of the segment polishing pad 37 can be imaged by the imaging means 10, and is, for example, a position directly below the polishing pad 35 shown by the alternate long and short dash line. The retracted position may be a position away from the imaging position and a position where the segment polishing pad 37 does not come into contact when polishing the workpiece. Then, the advancing / retreating means 20 causes the arm 22 to rotate in the horizontal direction by driving the motor 23 and rotating the shaft member 21, so that the imaging means 10 enters the imaging position or the imaging means 10 is retracted from the imaging position. It can be evacuated to.

The imaging means 10 includes a line sensor 11 extending in the radial direction in the radius of the processed surface 37a of the segment polishing pad 37 arranged in an annular shape on the base 36 and taking an image from a direction perpendicular to the processed surface 37a, and a line sensor. The first illumination 12 which extends parallel to 11 and is arranged in the vicinity of the line sensor 11 and irradiates light from a position near the line sensor 11 with respect to the machined surface 37a, and the outer peripheral tangential direction of the machined surface 37a. A second illumination 13 which is arranged away from the position of the line sensor 11 and irradiates light obliquely to the machined surface 37a, a switching means 14 for switching between the first illumination 12 and the second illumination 13, and a second. A determination means 15 for determining whether or not the processing surface 37a can continue processing is provided by using an image image obtained by switching between the illumination 12 of the first illumination 12 and the second illumination 13 and imaging the processing surface 37a by the imaging means 10. There is. The outer peripheral tangential direction of the machined surface 37a is the tangential direction of the tangent line passing through the center point of the outer peripheral edge of each segment polishing pad 37 shown in FIG.

The line sensor 11 has a configuration in which a CCD image sensor or a CMOS image sensor is linearly arranged. As shown in FIG. 4, the line sensor 11 has an optical axis 110 in the direction perpendicular to the machined surface 37a of the segment polishing pad 37. When the machined surface 37a is imaged by the line sensor 11, as shown in FIG. 5, the line sensor 11 is segmented while rotating the polishing pad 35 with the line sensor 11 positioned at the imaging position by the advancing / retreating means 20. By continuously imaging the processed surface 37a of the polishing pad 37, it is possible to capture an image in which the surface state of the processed surface 37a is projected.

The first illumination 12 and the second illumination 13 shown in FIG. 4 are composed of, for example, a plurality of LEDs. The first illumination 12 shown in the present embodiment has an optical axis 120 having an incident angle α1 close to perpendicular to the machined surface 37a of the segment polishing pad 37, and can illuminate the machined surface 37a with a so-called bright field of view. it can. On the other hand, the second illumination 13 has an optical axis 130 having an incident angle α2 inclined with respect to the processed surface 37a of the segment polishing pad 37, and can illuminate the processed surface 37a with a so-called dark field. The incident angle α2 is an angle that is more inclined than the incident angle α1 with respect to the optical axis 110 of the line sensor 11, and is configured such that the incident angle α2> the incident angle α1. The incident angle α1 and the incident angle α2 are not particularly limited, and are arbitrarily set depending on the distance from the processed surface 37a to which light is irradiated.

The switching means 14 can switch between the first lighting 12 and the second lighting 13 and turn them on. That is, when illuminating the machined surface 37a in a bright field of view, the switching means 14 selects and turns on the first illumination 12 and turns off the second illumination 13. On the other hand, when illuminating the machined surface 37a in a dark field, the switching means 14 selects and turns on the second illumination 13 and turns off the first illumination 12. According to the switching means 14, when the processed surface 37a is imaged by the imaging means 10 positioned at the imaging position, the first illumination 12 or the second illumination 13 is selected and turned on to illuminate the processed surface 37a. Therefore, it is possible to easily switch between the bright field and the dark field.

When the processing surface 37a is imaged by the imaging means 10 while the processing surface 37a is illuminated by the first illumination 12 switched by the switching means 14 while rotating the polishing pad 35 (when imaging in a bright field), the first illumination 12 When light is incident on the processed surface 37a of the segment polishing pad 37, the ratio of specular reflection on the processed surface 37a becomes stronger, so that the processed surface 37a appears black in the image. On the other hand, the part around the machined surface 37a and the part where foreign matter such as polishing debris adheres to the machined surface 37a has a strong diffuse reflection ratio, so that the part around the machined surface 37a and the part where foreign matter adheres appear white. ..

In the determination means 15 shown in FIG. 1, in order to analyze the image captured by the bright field, the number of brightly shining portions for each segment polishing pad 37 is equal to or more than a preset number, or each segment polishing pad 37 shines brightly. If the total area of the parts is equal to or greater than the preset area, it is determined that the machined surface 37a is abnormal, and the number of brightly shining parts for each segment polishing pad 37 is less than the preset number or shines brightly. A second determination unit 152 for determining that the machined surface 37a is normal when the total area of the portions is smaller than the preset area is provided. Here, the brightly shining portion is a portion of the processed surface 37a projected in black on the image captured in the bright field of view, to which foreign matter is attached. The portion where the foreign matter adheres to the processed surface 37a has a high ratio of diffuse reflection and the amount of light detected by the line sensor 11 increases, so that the portion is projected brightly with white contrast. In this way, the second determination unit 152 can detect how much foreign matter is attached to the processed surface 37a of the segment polishing pad 37 based on the number and area of the brightly shining portions.

Further, when the processing surface 37a is imaged by the imaging means 10 while the processing surface 37a is illuminated by the second illumination 13 switched by the switching means 14 while rotating the polishing pad 35 (when imaging in a dark field), the second When light is incident on the machined surface 37a of the segment polishing pad 37 from the illumination 13, the ratio of diffuse reflection on the machined surface 37a becomes stronger, so that the machined surface 37a appears white in the image and the portion around the machined surface 37a is covered. It looks black. Further, if the outer periphery of the segment polishing pad 37 is chipped, the chipped portion becomes a shadow and becomes black.

The determination means 15 is stored in a storage unit 150 and a storage unit 150 for storing an image obtained by capturing an image of the processed surface 37a of the segment polishing pad 37 in which no chipping has occurred in order to analyze the image captured by the dark field. Comparing the image with the image of the processed surface 37a after processing the workpiece, if the shapes of the segment polishing pads 37 match, continue processing, and if the shapes of the segment polishing pads 37 do not match, polish. It includes a first determination unit 151 that requests replacement of the pad 35. The shape of the segment polishing pad 37 means the outer shape of the segment polishing pad 37. Since the processed surface 37a appears white and the portion around the processed surface 37a appears black in the image captured in the dark field, the outer shape of the segment polishing pad 37 can be recognized. Then, in the first determination unit 151, by comparing the image stored in the storage unit 150 with the image image obtained by capturing the processed surface 37a after processing the workpiece, the segment polishing pad 37 is chipped or the like. It is possible to detect whether or not an abnormality has occurred.

Next, an operation example of polishing the workpiece using the processing apparatus 1 will be described. First, after the workpiece is placed on the holding surface 2a of the holding table 2 shown in FIG. 1, the suction force of a suction source (not shown) acts on the holding surface 2a to suck and hold the workpiece. The holding table 2 is moved in the Y-axis direction while rotating, and is moved below the processing means 3.

The spindle 30 rotates to rotate the polishing pad 35 while the moving means 4 polishes and feeds the polishing pad 35 in a direction approaching the holding table 2. The machined surface 37a of the segment polishing pad 37 that rotates while descending is brought into contact with the entire upper surface of the rotating workpiece, and the segment polishing pad 37 and the workpiece are relatively slid. In this way, the work piece is polished, and when the work piece reaches a desired thickness, the work piece 4 is raised in the direction away from the holding table 2 by the moving means 4, and the polishing process is completed.

Next, an operation example of measuring the surface state of the processed surface 37a of the segment polishing pad 37 after polishing the workpiece with the polishing pad 35 will be described. In the first example, after polishing one or a plurality of workpieces, for example, the processed surface 37a is illuminated by the imaging means 10 while illuminating the processed surface 37a of the segment polishing pad 37 with the second illumination 13. The case where the surface state of the machined surface 37a is measured by the determination means 15 will be described in detail. In this case, the storage unit 150 stores in advance an image 100 of the polishing pad 35 in a state where the outer shape of the segment polishing pad 37 shown in FIG. 6 is not chipped. The image 100 is an image of the machined surface 37a taken in advance by a dark field before the work piece is machined by the polishing pad 35. In the image 100, the portion of the polishing pad 35 is projected in white, and the periphery of the polishing pad 35 is projected in black. In the illustrated example, among the polishing pads 35 projected in white, the shades of the base 36 and the processed surface 37a of each segment polishing pad 37 arranged in a ring shape on the base 36 are different, and five segments. The outer shape of the polishing pad 37 is projected to the extent that it can be confirmed.

By driving the motor 23 of the advancing / retreating means 20 shown in FIG. 5, the shaft member 21 rotates to rotate the arm 22 to bring the imaging means 10 into the imaging position, and the line sensor 11 is moved to the machined surface of the segment polishing pad 37. Position horizontally just below 37a. Next, the processing means 3 rotates the spindle 30 to rotate the polishing pad 35 around the rotation center O in the direction of arrow A at, for example, 4 rpm.

By selecting and lighting the second illumination 13 by the switching means 14 shown in FIG. 4, light is incident obliquely toward the processing surface 37a of the segment polishing pad 37, and the processing surface 37a is illuminated by a dark field. While detecting the rotation angle with the rotary encoder and illuminating the machined surface 37a with the light of the second illumination 13, the line sensor 11 images the machined surface 37a for each segment polishing pad 37, and is shown on the left side of FIG. 7, for example. A strip-shaped image 101 is imaged. The imaging time is set to, for example, 15 seconds. In the image capture image 101, the portion of the polishing pad 35 is projected in white, and the periphery of the polishing pad 35 is projected in black. In the image capture image 101, the white-projected segment polishing pads 37 are aligned in a row, and like the image 100, the outer shape of the processed surface 37a is projected to the extent that the outer shape can be confirmed. In this image capturing image 101, a chip 39 (a portion provided with black color) is generated in the segment polishing pad 37 located at the lowermost side.

Next, the captured image 101 is converted into the captured image 102 shown on the right side of FIG. 7 by an image processing means (not shown). Here, the first determination unit 151 shown in FIG. 1 compares the image 100 stored in the storage unit 150 with the captured image 102 to perform image analysis. From the image 102, one segment polishing pad 37 is missing and 39 can be confirmed. Therefore, there is a difference in the area between the processed surface 37a of the segment polishing pad 37 projected in the image 100 and the processed surface 37a of the segment polishing pad 37 in which the chip 39 is generated, and the segment polishing pad 37 projected in the image 100 and the image are imaged. The shapes of the segment polishing pads 37 projected on the image 102 do not match. In this case, the first determination unit 151 determines that the polishing process cannot be continued because the processed surface 37a is abnormal, and requests the replacement of the polishing pad 35. The replacement request is displayed, for example, on a monitor (not shown) of the processing apparatus 1. On the other hand, when the shapes of the segment polishing pad 37 projected on the image 100 and the segment polishing pad 37 projected on the image 102 match, the first determination unit 151 assumes that the machined surface 37a is normal. Judge that the polishing process can be continued.

As described above, in the processing apparatus 1 of the first example, the processing surface 37a can be imaged by the imaging means 10 while selecting the second illumination 13 by the switching means 14 and illuminating the processing surface 37a of the segment polishing pad 37. Therefore, the image 100 stored in the storage unit 150 can be compared with the image 102 captured by the dark field, and it can be confirmed whether or not the segment polishing pad 37 is chipped 39. Therefore, it is possible to determine an appropriate replacement time of the polishing pad 35, and it is possible to prevent processing defects of the workpiece.
Further, in the processing apparatus 1, the first illumination 12 can be selected by the switching means 14 and the processed surface 37a can be imaged by the imaging means 10 while illuminating the processed surface 37a. It is possible to detect how much foreign matter is attached to the machined surface 37a. As described above, according to the present invention, the surface condition of the machined surface 37a of the segment polishing pad 37 can be measured to prevent excessive dressing and reduce the wear of the polishing pad 35. Therefore, the polishing pad can be reduced. The life of the 35 is extended, and the frequency of replacement of the polishing pad 35 can be reduced.

2 Second Example of Processing Device The processing device 5 shown in FIG. 8 is an example of a processing device that grinds an workpiece, and has an device base 5a extending in the Y-axis direction and a device base 5a in the Y-axis direction. It has a column 5b erected on the rear side. A holding table 6 for holding a work piece is arranged on the upper surface of the device base 5a. The upper surface of the holding table 6 is a holding surface 6a that sucks and holds the work piece. Below the holding table 6, a machining feeding means (not shown) for machining and feeding the holding table 6 in the horizontal direction (Y-axis direction) is arranged.

In front of the column 5b, a processing means 7 having a rotating means for rotating by mounting a processing tool for grinding the workpiece held by the holding table 6 and the processing means 7 approach and separate from the holding table 6. It is provided with a moving means 8 for moving in a direction (Z-axis direction). The moving means 8 is the same as the moving means 4 of the first example of the processing device, and extends in parallel with the ball screw 80 extending in the Z-axis direction, the motor 81 connected to one end of the ball screw 80, and the ball screw 80. A pair of guide rails 82 and an elevating plate 83 whose one surface is fixed to the processing means 7 are provided, and the other surface of the elevating plate 83 is slidably contacted with the pair of guide rails 82 inside the elevating plate 83. A ball screw 80 is screwed into the formed nut. By rotating the ball screw 80 by the motor 81, the processing means 7 can be moved in the Z-axis direction together with the elevating plate 83.

The processing means 7 has a spindle 70 having an axis in the vertical direction (Z-axis direction), a spindle housing 71 that rotatably surrounds the spindle 70, and a spindle 70 connected to one end of the spindle 70 so as to have the axis in the vertical direction. A motor 72 that is a rotating means that rotates as a center, a holder 73 that holds the spindle housing 71, a mounter 74 mounted on the lower end of the spindle 70, and a grinding tool that is detachably mounted on the lower surface of the mounter 74. It is equipped with a wheel 75. A plurality of segment grindstones 76 arranged in an annular shape are provided below the grinding wheel 75. Although not shown, the motor 72 is connected to a rotary encoder for detecting the rotation origin and rotation angle of the spindle 70. Then, the motor 72 rotates the spindle 70, so that the grinding wheel 75 can be rotated at a predetermined rotation speed.

In the grinding wheel 75 shown in the present embodiment, for example, as shown in FIG. 9, a plurality of segment grindstones 76 are adhesively fixed in an annular shape at the lower portion of the grinding wheel 75 at equal intervals, for example, by an adhesive. The number of the segment grindstones 76 is not particularly limited, but is, for example, 28. The outer diameter of the grinding wheel 75 is set to be substantially the same as the outer diameter of the mounter 74, for example, φ300 mm. The lower surface of the segment grindstone 76 arranged in an annular shape on the grinding wheel 75 is a machined surface 76a for grinding the workpiece. The outer diameter of the grinding wheel 75 and the shape and number of the segment grindstones 76 shown in the present embodiment are only one aspect and can be changed as appropriate. Further, the distance between the adjacent segment grindstones 76 may be appropriately set according to the material and size of the workpiece, the material of the segment grindstones 76, and the like.

Similar to the processing device 1, the processing device 5 shown in FIG. 8 has an imaging means 10A that images the processing surface 76a from a direction perpendicular to the processing surface 76a of the segment grindstone 76, and the imaging means 10A images the processing surface 76a. It is provided with advancing / retreating means 20A for entering a possible imaging position or retracting the imaging means 10A to a retracted position away from the imaging position. Since the configuration of the advancing / retreating means 20A is the same as that of the first example, a common reference numeral is attached. Also in the second example, the image pickup means 10A is mounted on the arm 22. The position may be any position as long as the machined surface 76a of the segment grindstone 76 can be imaged by the imaging means 10A, for example, the position directly below the grinding wheel 75 shown by the alternate long and short dash line. The retracted position may be a position away from the imaging position and a position where the segment grindstone 76 does not come into contact when grinding the workpiece.

Similar to the first example, the image pickup means 10A extends radially along the radius of the machined surface 76a of the segment grindstone 76 arranged in an annular shape on the grinding wheel 75 and images the image from the direction perpendicular to the machined surface 76a. A line sensor 11 to be provided, and a first illumination 12 extending in parallel with the line sensor 11 and arranged in the vicinity of the line sensor 11 to irradiate the machined surface 76a with light from a position near the line sensor 11. A second illumination 13 which is arranged away from the position of the line sensor 11 in the tangential direction of the outer periphery of the processed surface 76a and irradiates light obliquely to the processed surface 76a, and the first illumination 12 and the second illumination 13. It is determined whether or not the machined surface 76a can continue to be machined by using the image pickup image obtained by switching the switching means 14A for switching between the first illumination 12 and the second illumination 13 and imaging the processed surface 76a by the imaging means 10A. It is provided with a determination means 15A for making a judgment. The outer peripheral tangential direction of the machined surface 76a is the tangential direction of the tangent line passing through the center point of the outer peripheral edge of each segment grindstone 76 shown in FIG.

The determination means 15A is the same as the determination means 15 of the first example. That is, if the number of brightly shining portions for each segment grindstone 76 is equal to or greater than the preset number or the total area of the brightly shining portions for each segment grindstone 76 is equal to or greater than the preset area, the processing surface 76a Is abnormal, and if the number of brightly shining parts for each segment grindstone 76 is less than the preset number, or the total area of the brightly shining parts is smaller than the preset area, the machined surface 76a is normal. It is provided with a second determination unit 152 for determining that. The brightly shining portion is a portion of the processed surface 76a projected in black in the image captured in the bright field of view, to which foreign matter such as grinding dust is attached. Further, as in the first example, the determination means 15A has a storage unit 150 that stores an image of the processed surface 76a of the segment grindstone 76 in which no chipping has occurred, and an image and a workpiece stored in the storage unit 150. If the shapes of the segment grindstones 76 match, the machining is continued, and if the shapes of the segment grindstones 76 do not match, the grinding wheel 75 is requested to be replaced. It includes a first determination unit 151. The shape of the segment grindstone 76 means the outer shape of the segment grindstone 76.

Next, an operation example of grinding the workpiece using the processing device 5 will be described. First, after the workpiece is placed on the holding surface 6a of the holding table 6 shown in FIG. 8, the suction force of a suction source (not shown) is applied to the holding surface 6a to suck and hold the workpiece. The holding table 6 is moved in the Y-axis direction while rotating, and is moved below the processing means 7.

The spindle 70 rotates to rotate the grinding wheel 75 while the moving means 8 grinds and feeds the grinding wheel 75 in a direction approaching the holding table 6. Grinding to a predetermined thickness while pressing the upper surface of the workpiece rotating on the machined surface 76a of the segment grindstone 76 that rotates while descending. In this way, the workpiece is ground, and when the workpiece reaches a desired thickness, the moving means 8 raises the machining means 7 in a direction away from the holding table 6, and the grinding process is completed.

Next, an operation example of measuring the surface state of the machined surface 76a of the segment grindstone 76 after grinding the workpiece by the grinding wheel 75 will be described. In the second example, after performing the above-mentioned grinding process on one or a plurality of workpieces, for example, the processed surface 76a is illuminated by the imaging means 10A while illuminating the processed surface 76a of the segment grindstone 76 with the first illumination 12. The case where the surface state of the machined surface 76a is measured by the determination means 15A will be described in detail.

By driving the motor 23 of the advancing / retreating means 20A shown in FIG. 8, the shaft member 21 rotates to rotate the arm 22 to bring the imaging means 10A into the imaging position, and as shown in FIG. 10, the line sensor 11 is segmented. It is positioned horizontally just below the machined surface 76a of the grindstone 76. By rotating the spindle 70, the processing means 7 rotates the grinding wheel 75 around the rotation center O in the direction of arrow B at, for example, 60 rpm.

The first illumination 12 is selected and turned on by the switching means 14 shown in FIG. 8, and the machined surface 76a is illuminated by the bright field. While detecting the rotation angle with the rotary encoder and illuminating the machined surface 76a with the light of the first illumination 12, the line sensor 11 images the machined surface 76a for each segment grindstone 76. For example, the image 200 shown in FIG. To image. The imaging time is set to, for example, 1 second. The image capture image 200 shows an enlarged image in which one segment grindstone 76 is projected by a bright field of view, but the 28 segment grindstones 76 shown in FIG. 9 are projected in the actual image. In the image capture image 200, the processed surface 76a of the segment grindstone 76 is projected in black, and the periphery of the processed surface 76a of the segment grindstone 76 (grinding wheel 75, etc.) is projected in white. Of the processed surface 76a projected in black on the image 200, the portion that shines with white contrast is the portion to which the foreign matter 77 is attached.

Here, for example, when the processed surface 76a of the segment grindstone 76 is imaged in a dark field, the image image 201 shown in FIG. 12 can be imaged, but the processed surface 76a of the segment grindstone 76 is projected in white in the image image 201. Since the area around the machined surface 76a is projected in black, the outer shape of the segment grindstone 76 can be confirmed from the image 201, but the contrast of the foreign matter 77 adhering to the machined surface 76a is not clear, and the foreign matter 77 can be confirmed. difficult. Therefore, in the image pickup image 200 shown in FIG. 11, the foreign matter 77 adhering to the processed surface 76a of the segment grindstone 76 is remarkably projected as compared with the image pickup image 201, so that the surface state of the processed surface 76a can be confirmed. it can.

The second determination unit 152 shown in FIG. 8 counts the number of foreign matter 77 for each segment grindstone 76 by image analysis of the image 200, or totals the area of foreign matter 77 for each segment grindstone 76. Calculate the value. In the second determination unit 152, the number of foreign matters 77 adhering to each machined surface 76a is equal to or greater than the number set in advance in the processing apparatus 5, or the total area of the foreign matters 77 is equal to or greater than the value set in advance in the processing apparatus 5. Then, it is determined that the machined surface 76a is abnormal. When counting the number of foreign matter 77, it is preferable to classify the foreign matter 77 according to the size of the foreign matter 77 in order to select the optimum processing conditions. The machining conditions include the grinding feed rate of the machining means 7, the rotation speed of the spindle 70, the amount of grinding water, the outer diameter of the grinding wheel 75, the shape and number of the segment grindstones 76, and the like.

If the second determination unit 152 determines that the machined surface 76a of the segment grindstone 76 is abnormal, the grinding process cannot be continued. Therefore, the segment grindstone 76 may be dressed or the grinding wheel 75 may be dressed. May be requested to be replaced. Further, when the size of the foreign matter 77 is classified, the setting of the processing conditions of the workpiece may be changed. For example, when a large amount of large foreign matter adheres to the machined surface 76a, it is advisable to slow down the grinding feed speed of the machining means 7 by the moving means 8 and change the setting of the rotation speed of the spindle 70 significantly. As a result, it is possible to reduce the amount of foreign matter adhering to the machined surface 76a of the segment grindstone 76 after grinding the workpiece. If a large amount of small foreign matter adheres to the machined surface 76a, it is advisable to change the setting to increase the amount of grinding water used during grinding. As a result, the amount of grinding water that flows into the contact surface between the segment grindstone 76 and the workpiece increases, so that small foreign matter is easily discharged.

On the other hand, the second determination unit 152 counts the number of foreign matter 77 for each segment grindstone 76 by analyzing the image 200, or calculates the total area of the foreign matter 77 for each segment grindstone 76. As a result, if the number of foreign matters 77 adhering to each machined surface 76a is smaller than the number preset in the machining apparatus 5, or the total area of the foreign matters 77 is smaller than the value preset in the machining apparatus 5. It is determined that the machined surface 76a is normal. In this case, the grinding process can be continued.

As described above, in the processing device 5 of the second example, similarly to the processing device 1, the first illumination 12 is selected by the switching means 14, and the processing surface is illuminated by the imaging means 10A while illuminating the processing surface 76a of the segment grindstone 76. Since the 76a can be imaged, the image 200 in the bright field can be imaged, and the image 200 is analyzed to calculate the number of brightly shining parts and the area of the brightly shining part to calculate the foreign matter on the processed surface 76a. It is possible to detect how much 77 is attached. As described above, according to the present invention, the surface condition of the machined surface 76a of the segment grindstone 76 can be measured to prevent excessive dressing and reduce the wear of the grinding wheel 75. Therefore, the grinding wheel 75 can be reduced. The life of the grinding wheel 75 is extended, and the frequency of replacement of the grinding wheel 75 can be reduced.
Further, also in the processing apparatus 5 of the second example, the processing surface 76a can be imaged by the imaging means 10A while selecting the second illumination 13 by the switching means 14 and illuminating the processing surface 76a. An image captured by the same dark field can be captured, and the image stored in the storage unit 150 is compared with the image captured by the dark field to determine whether or not the segment grindstone 76 is chipped. You can check it. Therefore, an appropriate replacement time of the grinding wheel 75 can be determined, and processing defects of the workpiece can be prevented.

1: Processing device 1a: Equipment base 1b: Column 2: Holding table 3: Processing means 30: Spindle 31: Spindle housing 32: Motor 33: Holder 34: Mounter 35: Polishing pad 36: Base 37: Segment polishing pad 37a: Machining surface 38: Bolt 39: Chip 4: Moving means 40: Ball screw 41: Motor 42: Guide rail 43: Elevating plate 5: Machining device 5a: Device base 5b: Column 6: Holding table 7: Machining means 70: Spindle 71: Spindle housing 72: Motor 73: Holder 74: Mounter 75: Grinding wheel 76: Segment grindstone 76a: Machined surface 77: Adhesion 8: Transportation means 80: Ball screw 81: Motor 82: Guide rail 83: Lifting plate 10, 10A: Imaging Means 11: Line sensor 12: First lighting 13: Second lighting 14: Switching means 15, 15A: Judgment means 150: Storage unit 151: First judgment unit 152: Second judgment unit 20, 20A: Advance / retreat Means 21: Shaft member 22: Arm 23: Motor

Claims (3)

A processing means having a holding table for holding a work piece, a rotating means for rotating by attaching a processing tool for grinding or polishing the work piece held by the holding table, and the processing means for the holding table. A processing device provided with a moving means for moving in the approaching and separating directions.
An imaging means for imaging the machined surface from a direction perpendicular to the machined surface of the tool,
The imaging means includes an advancing / retreating means for entering an imaging position where the processed surface can be imaged or retracting the imaging means to a retracted position away from the imaging position.
The tool comprises a grinding wheel in which a plurality of segment grindstones are arranged in an annular shape or a polishing pad in which a plurality of segment polishing pads are arranged in an annular shape.
The imaging means extends in the radial direction in the radius of the processed surface of the segment grindstone arranged in an annular shape or the segment polishing pad arranged in an annular shape, and an image is taken from a direction perpendicular to the processed surface. With the sensor
A first illumination extending parallel to the line sensor, arranged in the vicinity of the line sensor, and irradiating the machined surface with light from a position near the line sensor.
A second illumination that is arranged away from the position of the line sensor in the tangential direction of the outer circumference of the machined surface and irradiates the machined surface with light at an angle.
A switching means for switching between the first illumination and the second illumination,
It is provided with a determination means for determining whether or not the processed surface can continue processing by using an image image obtained by switching between the first illumination and the second illumination and imaging the processed surface by the imaging means. Processing equipment. While rotating the processing tool, the processing surface is illuminated by the first illumination switched by the switching means, and the processing surface is imaged by the imaging means.
The determination means uses an image of the processed surface of the processing tool after processing the workpiece, and the number of brightly shining portions for each of the segment grindstones or the segment polishing pads is equal to or greater than a preset number or more. If the total area of the brightly shining portions of the segment grindstone or the segment polishing pad is equal to or greater than the preset area, it is determined that the machined surface is abnormal.
If the number of brightly shining parts for each of the segment grindstones or the segment polishing pads is less than the preset number, or the total area of the brightly shining parts is smaller than the preset area, the machined surface is normal. The processing apparatus according to claim 1, further comprising a second determination unit for determination. While rotating the processing tool, the processing surface is illuminated by the second illumination switched by the switching means, and the processing surface is imaged by the imaging means.
The determination means includes a storage unit that stores an image of the processed surface of the segment grindstone or the segment polishing pad that has not been chipped.
The image stored in the storage unit is compared with the image taken by imaging the processed surface after the workpiece is processed with the processing tool, and if the shapes match, the processing is continued and the shapes do not match. The processing apparatus according to claim 1, further comprising a first determination unit for requesting replacement of the grinding wheel or the polishing pad.

Images