Conveying device

Abstract

To provide a carrier device that makes it easier for an operator to carry out a workpiece from a cassette.SOLUTION: The position of a robot hand to be inserted into a cassette when carrying out a workpiece from the cassette is determined by referring to a plurality of images formed by imaging by an imaging unit. Therefore, there is no need for an operator to know in advance the detailed structure of the cassette and the warping or bending of the workpieces accommodated in the cassette. As a result, the operator's work when carrying out the workpiece from the cassette becomes easier.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a conveying device for conveying a workpiece.

Background Art

[0002] Chips of devices such as ICs (Integrated Circuits) are essential components in various electronic devices such as mobile phones and personal computers. Such chips are manufactured, for example, by dividing a workpiece such as a wafer having a large number of devices formed on its surface into regions each including an individual device.

[0003] The workpiece on which the device is formed is often thinned before being divided for the purpose of miniaturization and weight reduction of the chip. As a method of thinning the workpiece, for example, there is grinding by a grinding device having a chuck table that holds the surface (lower surface) side of the workpiece and a grinding wheel provided above the chuck table and including a plurality of grinding wheels arranged annularly and discretely.

[0004] In order to grind the workpiece in this way, it is necessary to carry the workpiece into the grinding device as a prerequisite. For example, in a general chip manufacturing process, a lot (about 25 pieces) of workpieces are accommodated in a cassette, and this cassette is carried onto the placement surface of a cassette table provided in the grinding device. Further, the grinding device generally has a transfer robot (unloading means) that holds the workpiece with a robot hand and unloads it from the cassette (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] A cassette generally has a pair of side walls that face each other and each side has multiple grooves formed on its inner surface. In a cassette, a workpiece, such as a wafer, is housed with its outer edge positioned in one of the multiple grooves. On the other hand, the detailed structure of the cassette, such as the spacing between the pair of side walls and the spacing between the multiple grooves, often varies depending on the size of the workpiece to be housed.

[0007] Therefore, when using a transport robot to unload a workpiece from a cassette, the operator must first understand the detailed structure of the cassette and input information into the transport robot to set the appropriate position for the robot hand to be inserted into the cassette. However, if there are many different types of cassettes with varying detailed structures, it is cumbersome for the operator to understand the detailed structure of each cassette individually.

[0008] Furthermore, even with cassettes of the same type, dimensional errors may occur in the detailed structure of the cassette due to differences in the manufacturer or manufacturing lot. In such cases, when using a transport robot to unload a workpiece from the cassette, it may be difficult for the operator to set the appropriate position of the robot hand to be inserted into the cassette, even if they refer to information that they have in advance.

[0009] Furthermore, warping or bending of the workpiece contained in the cassette may cause the appropriate position of the robot hand inserted into the cassette to unload the workpiece to change. In such cases, the operator needs to constantly be aware of the appropriate position of the robot hand as it is inserted into the cassette, but this is a cumbersome task.

[0010] In view of these points, the object of the present invention is to provide a conveying device that simplifies the operator's work when unloading a workpiece from a cassette. [Means for solving the problem]

[0011] According to the present invention, a conveying device comprising: a cassette table having a mounting surface on which a cassette containing a workpiece is placed, having a pair of opposing side walls, with the outer edge of the cassette positioned in one of a plurality of grooves formed on the inner surface of each of the pair of side walls; a conveying robot for unloading the workpiece from the cassette; and a control unit for controlling the operation of the conveying robot, wherein the conveying robot has a conveying arm having a tip that is movable in a first direction perpendicular to the mounting surface and a second direction parallel to the mounting surface; a robot hand disposed at the tip of the conveying arm and capable of holding the workpiece; and an imaging unit fixed to the conveying arm and capable of imaging an area contained in the cassette placed on the mounting surface, and the control unit, Memory unit and, Using the imaging unit, the cassette containing the workpiece... To Take an image One or multiple 1 After forming the image to the one or multiple 1 Refer to the image. First data indicating the first position to be determined and , The storage unit stores, and, after imaging different areas of the mounting surface of the cassette table on which the cassette is placed using the imaging unit to form a plurality of second images, second data indicating a second position determined by referring to the plurality of second images, and, The position of the robot hand in the first direction when it is inserted into the cassette to unload the workpiece from the cassette. As it becomes the first position Position in the second direction The transport robot is operated so that it is in the second position. ru A processing unit having A conveying device is provided.

[0012] Preferably, One or multiple 1 The image includes a side wall image formed by imaging a region of the plurality of grooves that includes two or more adjacent grooves in the first direction, 1st position Refer to the side wall image. Measured The spacing between the multiple grooves in the first direction Please refer Illumination Decision fixed So ru. [Effects of the Invention]

[0013] In the present invention, referring to a plurality of images formed by imaging with an imaging unit, the position of a robot hand inserted into a cassette when carrying out a workpiece from the cassette is determined. Therefore, in the present invention, it is not necessary for an operator to grasp in advance the detailed structure of the cassette and the warp or deflection of the workpiece accommodated in the cassette. As a result, the work of the operator when carrying out the workpiece from the cassette is simplified.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a perspective view schematically showing an example of a grinding apparatus including a transfer device for transferring a workpiece. [Figure 2] FIG. 2 is a perspective view schematically showing an example of a transfer robot. [Figure 3] FIG. 3 is a perspective view schematically showing an example of a workpiece. [Figure 4] FIG. 4 is a perspective view schematically showing an example of a cassette. [Figure 5] FIG. 5 is a plan view schematically showing a turntable and the structure around it. [Figure 6] Each of FIGS. 6(A), 6(B) and 6(C) is a perspective view schematically showing an example of the operation state of a transfer robot when carrying out a workpiece from a cassette.

Embodiments for Carrying out the Invention

[0015] Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing an example of a grinding apparatus including a transfer device for transferring a workpiece. In FIG. 1, some of the components of the grinding apparatus are shown as functional blocks. Also, the X-axis direction (front-rear direction) and the Y-axis direction (left-right direction) shown in FIG. 1 are directions perpendicular to each other on a horizontal plane, and the Z-axis direction (up-down direction, height direction) is a direction (vertical direction) perpendicular to the X-axis direction and the Y-axis direction.

[0016] The grinding apparatus 2 shown in Figure 1 includes a base 4 that supports various components. An opening 4a is formed on the front end side of the upper surface of the base 4, and a transport robot 6 and a Y-axis movement mechanism (not shown) that moves the transport robot 6 along the Y-axis are provided inside the opening 4a. This Y-axis movement mechanism includes, for example, a ball screw and a motor.

[0017] Figure 2 is a schematic perspective view of the transport robot 6. The transport robot 6 has a cylindrical first drive unit 8 that extends along the Z-axis direction. The lower part of this first drive unit 8 is fixed to a Y-axis movement mechanism. Inside the first drive unit 8, there is an actuator (not shown), such as an air cylinder, which has a piston rod that can move along the Z-axis direction and can rotate around a rotation axis along the Z-axis direction.

[0018] Furthermore, an opening is provided on the upper surface of the first drive unit 8 through which the piston rod passes. The upper end of this piston rod is connected to the transport arm 10. Therefore, the transport arm 10 is movable along the Y-axis and Z-axis directions. That is, when the Y-axis movement mechanism is operated, the transport arm 10 moves along the Y-axis direction together with the first drive unit 8. Also, when the actuator provided inside the first drive unit 8 is operated, the transport arm 10 moves (rises and falls) along the Z-axis direction.

[0019] The transport arm 10 is a robotic arm with multiple joints. Specifically, the transport arm 10 has a plate-shaped first arm portion 10a that extends in a direction perpendicular to the Z-axis direction. The lower side of one end of this first arm portion 10a is connected to the upper end of the piston rod so as to move and rotate together with the piston rod. The lower side of a cylindrical first joint portion (not shown) is connected to the upper side of the other end of the first arm portion 10a.

[0020] A plate-shaped second arm portion 10b, extending perpendicular to the Z-axis direction, is connected to the upper side of the first joint portion. The lower side of one end of this second arm portion 10b is connected to the upper side of the other end of the first arm portion 10a via the first joint portion in a manner that allows it to rotate around a rotation axis along the Z-axis direction. Furthermore, the lower side of a cylindrical second joint portion 10c is connected to the upper side of the other end of the second arm portion 10b.

[0021] A rectangular parallelepiped second drive unit 10d, extending in a direction perpendicular to the Z-axis direction, is connected to the upper side of the second joint portion 10c. The lower side of one end of this second drive unit 10d is connected to the upper side of the other end of the second arm portion 10b via the second joint portion 10c in a manner that allows it to rotate around a rotation axis along the Z-axis direction.

[0022] Furthermore, an imaging unit 12 is fixed to the side of the second drive unit 10d, extending in the same direction as the second drive unit 10d. This imaging unit 12 includes, for example, a light source such as an LED (Light Emitting Diode), an objective lens, and an image sensor such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging unit 12 then images structures located in the direction from the other end to the one end of the second drive unit 10d, as viewed from the imaging unit 12, and forms an image.

[0023] Furthermore, a motor (not shown) is provided inside the second drive unit 10d to rotate a spindle 10e that is rotatable along a direction perpendicular to the Z-axis. The tip of this spindle 10e is exposed to the outside through an opening formed on the other end face of the second drive unit 10d. The rectangular base end of the robot hand 14 is connected to the tip of the spindle 10e via a plate-shaped connecting part 10f. In other words, the robot hand 14 is positioned at the tip of the transport arm 10.

[0024] Furthermore, the robot hand 14 has an elliptical plate-shaped portion integrated with its base end. Specifically, this portion has a shape such that the major axis of the ellipse is parallel to the spindle 10e, and a linear notch is provided in this portion from its center toward the tip. In addition, a plurality of suction holes (not shown) are provided on one surface of the elliptical plate-shaped portion of the robot hand 14.

[0025] This suction hole is connected to a suction source (not shown), such as an ejector, via a flow path and valves that control the gas flow, which are located inside the robot hand 14. When the suction source is operated with this valve open, a suction force acts on the space near one surface of the elliptical plate-shaped portion of the robot hand 14.

[0026] Therefore, this surface functions as a holding surface for suction and holding the workpiece. Furthermore, in the transfer robot 6, the workpiece can be inverted by rotating the spindle 10e while the workpiece is held on the holding surface of the robot hand 14. In other words, the workpiece can be held on either the upper or lower side of the robot hand 14.

[0027] Figure 3 is a schematic perspective view showing an example of a workpiece being transported by a transport robot 6. The workpiece 11 shown in Figure 3 is, for example, a wafer made of a semiconductor material such as silicon (Si). The workpiece 11 is divided into multiple regions by multiple intersecting division lines 13, and a device 15 such as an IC or LSI is formed on the surface 11a side of each region.

[0028] There are no restrictions on the material, shape, structure, or size of the workpiece 11. For example, the workpiece 11 may be a substrate made of other semiconductor materials, ceramics, resins, metals, etc. Similarly, there are no restrictions on the type, quantity, shape, structure, size, or arrangement of the devices 15.

[0029] Furthermore, a film-like tape having a diameter approximately equal to the diameter of the workpiece 11 may be attached to the surface 11a of the workpiece 11. This tape, for example, is made of resin and protects the device 15 by mitigating the impact applied to the surface 11a when grinding the back surface 11b of the workpiece 11.

[0030] Figure 4 is a schematic perspective view showing an example of a cassette for containing a workpiece 11. The cassette 16 shown in Figure 4 has a flat top plate 16a. This top plate 16a has a shape in which two adjacent corners of a rectangular flat plate are chamfered, while the remaining two corners remain unchamfered.

[0031] Furthermore, the upper end of a side wall (not shown) extending perpendicular to the top plate 16a (in the height direction) is fixed to the underside of the end (rear end) located between the pair of chamfered portions of the top plate 16a. In addition, the upper ends of side walls 16b and 16c extending in the height direction are fixed to the underside of each of the two ends (left end and right end) located between the chamfered portion and the unchamfered corner of the top plate 16a.

[0032] On the other hand, no side wall extending in the height direction is fixed to the underside of the end (front end) located between the pair of unchamfered corners of the top plate 16a. That is, the underside of the front end of the top plate 16a is open and forms an open surface. In addition, grooves 16d are formed on the inner surfaces of the side walls 16b and 16c at predetermined intervals in the height direction and extending in a direction perpendicular to the height direction.

[0033] Specifically, each of the multiple grooves 16d formed on the inner surface of the side wall 16b is positioned to face one of the multiple grooves 16d formed on the inner surface of the side wall 16c. Furthermore, the cross-sectional shape of the grooves 16d is generally rectangular. In other words, each groove 16d has a pair of inner surfaces that are generally perpendicular to the height direction and a bottom surface that is generally parallel to the height direction.

[0034] Then, by placing the outer edge of the workpiece 11 on the inner surface of each of the multiple grooves 16d that is furthest from the top plate 16a, the workpiece 11 is housed in the cassette 16. In other words, the outer edge of the workpiece 11 is supported on the inner surface of a pair of opposing grooves 16d that is furthest from the top plate 16a.

[0035] There are no restrictions on the number of grooves 16d formed on the inner surface of the side wall 16b and the inner surface of the side wall 16c. For example, the cassette 16 may be provided with a number of grooves 16d corresponding to one lot (approximately 25 pieces) of workpieces 11.

[0036] Furthermore, the lower part of side wall 16b and the lower part of side wall 16c are connected via an elongated plate-shaped connecting member 16e. The cassette 16 is then loaded, for example, with multiple workpieces 11 inside, onto the cassette tables 18a and 18b of the grinding apparatus 2 shown in Figure 1.

[0037] The cassette tables 18a and 18b have upper surfaces (mounting surfaces) parallel to the X-axis and Y-axis directions, and a rectangular prism-shaped cassette stopper 19 extending along the Y-axis direction is provided at the end of the mounting surface on the opening 4a side. The cassette 16 is placed on the mounting surface of the cassette tables 18a and 18b such that the opening surface is located on the opening 4a side and the lower ends of the side walls 16b and 16c are in contact with the cassette stopper 19.

[0038] In this case, the outer surfaces of the side walls 16b and 16c of the cassette 16 become parallel to the X-axis direction. This prevents the robot hand 14 of the transport robot 6 from colliding with the inner surfaces of the side walls 16b and 16c when it is inserted into the cassette 16.

[0039] Furthermore, a position adjustment mechanism 20 for adjusting the position of the workpiece 11 is provided diagonally behind the transport robot 6. The position adjustment mechanism 20 comprises, for example, a disc-shaped table 20a having an upper surface (support surface) capable of supporting the workpiece 11, and a plurality of pins 20b arranged around the table 20a.

[0040] When the workpiece 11, which has been unloaded from the cassette 16 by the transport robot 6, is placed on the support surface of the table 20a, the multiple pins 20b move along the radial direction of the table 20a so as to contact the outer edge of the workpiece 11. This aligns the center of the workpiece 11 to a predetermined position in the X-axis and Y-axis directions. Details of the unloading of the workpiece 11 from the cassette 16 by the transport robot 6 will be described later.

[0041] A transport mechanism 22 is provided diagonally behind the position adjustment mechanism 20 (behind the transport robot 6) to hold the workpiece 11 and transport it backward. The transport mechanism 22 comprises a holding pad that sucks and holds the workpiece 11, and an arm connected to this holding pad. The transport mechanism 22 then transports the workpiece 11, whose position has been adjusted by the position adjustment mechanism 20, backward by rotating the holding pad with the arm.

[0042] A disc-shaped turntable 24 is provided behind the conveying mechanism 22. The turntable 24 is connected to a rotational drive source (not shown), such as a motor, and rotates around a rotation axis that is roughly parallel to the Z-axis direction. Three chuck tables 26 capable of holding the workpiece 11 are provided on the upper surface of the turntable 24.

[0043] The three chuck tables 26 are arranged at roughly equal intervals along the circumferential direction of the turntable 24. There are no restrictions on the number of chuck tables 26 that can be arranged on the turntable 24. Figure 5 is a schematic plan view showing the structure of the turntable 24 and its surroundings.

[0044] Note that in Figure 5, some components are shown with dashed lines for ease of explanation. The conveying mechanism 22 carries the workpiece 11 held by the holding pad to the chuck table 26 located in the loading / unloading area A (see Figure 5) adjacent to the conveying mechanism 22. The turntable 24 rotates, for example, in the direction indicated by the arrows in Figures 1 and 5, moving each chuck table 26 in the order of loading / unloading area A, rough grinding area B, and finish grinding area C.

[0045] Each chuck table 26 is connected to a rotational drive source (not shown), such as a motor, and rotates around a rotation axis that is generally parallel to the Z-axis direction. Each chuck table 26 has a disc-shaped frame made of a metal material such as stainless steel. A recess with a circular opening at its upper end is formed on the upper side of this frame, and a disc-shaped porous plate made of ceramics or the like is fixed in this recess.

[0046] The upper surface of the chuck table 26 is configured to have a shape corresponding to the side of a cone with its center slightly protruding beyond its outer edge, and functions as a holding surface 26a for holding the workpiece 11. In other words, the chuck table 26 is equipped with a holding surface 26a for holding the workpiece 11 on its upper surface.

[0047] The holding surface 26a is connected to a suction source (not shown), such as an ejector, via a suction passage (not shown) formed inside the chuck table 26. The workpiece 11, when placed on the chuck table 26, is held in place by the suction force acting in the space near the holding surface 26a.

[0048] As shown in Figure 1, columnar support structures 28 are provided behind the rough grinding area B and the finish grinding area C (behind the turntable 24). A Z-axis movement mechanism 30 is provided on the front side of the support structure 28. The Z-axis movement mechanism 30 is fixed to the front of the support structure 28 and includes a pair of guide rails 32 that extend along the Z-axis direction.

[0049] A movable plate 34 is connected to the front side of a pair of guide rails 32 in a manner that allows it to slide along the pair of guide rails 32. A screw shaft 36 extending along the Z-axis direction is positioned between the pair of guide rails 32. A motor 38 for rotating the screw shaft 36 is connected to one end of this screw shaft 36.

[0050] Furthermore, a nut portion (not shown) is provided on the surface of the screw shaft 36, where a helical groove is formed, to accommodate balls that roll on the surface of the rotating screw shaft 36, thus forming a ball screw. That is, when the screw shaft 36 rotates, the balls circulate within the nut portion, causing the nut portion to move along the Z-axis direction. This nut portion is also fixed to the rear (back) side of the movable plate 34.

[0051] Therefore, by rotating the screw shaft 36 with a motor 38 connected to one end of the screw shaft 36, the movable plate 34 moves along the Z-axis direction together with the nut. In addition, a fixing device 40 is provided on the front (surface) side of the movable plate 34. The fixing device 40 supports a grinding unit 42 for grinding the workpiece 11. This grinding unit 42 includes a spindle housing 44 fixed to the fixing device 40.

[0052] The spindle housing 44 houses a spindle 46 that rotates around a rotation axis along the Z-axis direction, in a manner that allows it to rotate. The lower end of the spindle 46 is exposed from the lower end surface of the spindle housing 44. A disc-shaped mount 48 is fixed to the exposed lower end of the spindle 46.

[0053] A first grinding wheel 50a for rough grinding is mounted on the lower surface of the mount 48 of the grinding unit 42 on the rough grinding area B side. This first grinding wheel 50a for rough grinding is equipped with a first wheel base made of a metal such as stainless steel or aluminum and having approximately the same diameter as the mount 48.

[0054] Multiple first grinding wheels, each composed of abrasive grains such as diamond suitable for rough grinding fixed with a bond such as vitrified or resinoid, are arranged in an annular pattern on the lower surface of the first wheel base. In addition, a first rotational drive source (not shown), such as a motor, connected to the upper end of the spindle 46, is housed in the spindle housing 44 of the grinding unit 42 on the rough grinding area B side.

[0055] Then, when the spindle 46 is rotated by the power of the first rotational drive source, the first grinding wheel 50a rotates. A liquid supply nozzle (not shown) is provided next to the first grinding wheel 50a, which can supply a liquid (grinding fluid) such as pure water to the part (processing point) where the workpiece 11 and the first grinding wheel come into contact. However, a liquid supply port used for supplying liquid may be provided on the first grinding wheel 50a instead of this liquid supply nozzle, or together with the liquid supply nozzle.

[0056] Similarly, a second grinding wheel 50b for finish grinding is mounted on the lower surface of the mount 48 of the grinding unit 42 on the finish grinding area C side. This second grinding wheel 50b for finish grinding is equipped with a second wheel base made of a metal such as stainless steel or aluminum and having approximately the same diameter as the mount 48.

[0057] Multiple second grinding wheels, each composed of abrasive grains such as diamond suitable for finish grinding fixed with a bond such as vitrified or resinoid, are arranged in a ring shape on the lower surface of the second wheel base. In addition, a second rotational drive source (not shown), such as a motor, connected to the upper end of the spindle 46, is housed in the spindle housing 44 of the grinding unit 42 on the finish grinding area C side.

[0058] Then, when the spindle 46 is rotated by the power of the second rotational drive source, the second grinding wheel 50b rotates. In addition, a liquid supply nozzle (not shown) is provided next to the second grinding wheel 50b that can supply a liquid (grinding fluid) such as pure water to the part (machining point) where the workpiece 11 and the second grinding wheel come into contact. However, a liquid supply port used for supplying liquid may be provided on the second grinding wheel 50b instead of this liquid supply nozzle, or together with the liquid supply nozzle.

[0059] The workpieces 11 held on each chuck table 26 are sequentially ground by the two sets of grinding units 42 described above. Specifically, the workpieces 11 held on the chuck table 26 in the rough grinding area B are ground by the grinding unit 42 on the rough grinding area B side, and the workpieces 11 held on the chuck table 26 in the finish grinding area C are ground by the grinding unit 42 on the finish grinding area C side.

[0060] A transport mechanism 52 is provided in front of the loading / unloading area A and to the side of the transport mechanism 22, which holds the ground workpiece 11 and transports it forward. The transport mechanism 52 comprises a holding pad that sucks and holds the workpiece 11, and an arm connected to the holding pad. The transport mechanism 52 then transports the ground workpiece 11 forward from the chuck table 26 by rotating the holding pad with the arm.

[0061] In front of the conveying mechanism 52, a cleaning unit 54 is provided for cleaning the workpiece 11 that has been transported by the conveying mechanism 52. The cleaning unit 54 includes, for example, a spinner table 54a that has an upper surface (support surface) capable of supporting the workpiece 11 and rotates while holding the workpiece 11 on this support surface, and a nozzle (not shown) that sprays cleaning fluid onto the workpiece 11 held by the spinner table 54a.

[0062] The workpiece 11, cleaned in the cleaning unit 54, is unloaded from the spinner table 54a by the transport robot 6 and loaded into the cassette 16. The operation of each component of the grinding device 2 is controlled by a control unit 56 built into the grinding device 2. The control unit 56 includes, for example, a processing unit 58 that controls the components of the grinding device 2, and a storage unit 60 that stores various information (data and programs, etc.) used in the processing unit 58.

[0063] The memory unit 60 stores, for example, the width (length along the Y-axis) of the mounting surfaces of the cassette tables 18a and 18b. The functions of the processing unit 58 are implemented by a CPU (Central Processing Unit) or the like that reads and executes the programs stored in the memory unit 60. The functions of the memory unit 60 are implemented by at least one of semiconductor memory such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), and NAND flash memory, and a magnetic storage device such as an HDD (Hard Disk Drive).

[0064] Furthermore, the grinding device 2 may include components other than those described above. For example, the grinding device 2 may include a touch panel comprising a touch sensor that inputs instructions from the operator to the control unit 56 and a display that outputs various information to the operator.

[0065] The grinding apparatus 2 shown in Figure 1 can also be described as having a transport system centered around a transport robot 6. Specifically, this transport system includes cassette tables 18a and 18b having a mounting surface on which the cassette 16 is placed, a transport robot 6 that unloads the workpiece 11 from the cassette 16, and a control unit 56 that controls the operation of the transport robot 6.

[0066] In the following, an example of the operation of the transport robot 6 when unloading the workpiece 11 from the cassette 16 will be described with reference to Figures 6(A), 6(B), and 6(C). In this operation, first, the cassette 16 is placed on the mounting surface of the cassette tables 18a and 18b such that the opening surface is located on the opening 4a side and the lower ends of the side walls 16b and 16c are in contact with the cassette stopper 19. Next, the imaging unit 12 is positioned so that it can image one end of the mounting surface of the cassette tables 18a and 18b and the space directly above it.

[0067] Specifically, the processing unit 58 operates the Y-axis movement mechanism located inside the opening 4a so that the transport robot 6 is positioned behind one end of the mounting surface of the cassette tables 18a and 18b. The processing unit 58 then controls the actuator located inside the first drive unit 8 of the transport robot 6 to raise and lower the imaging unit 12 and other components, and rotates the first arm 10a, the second arm 10b, and / or the second drive unit 10d, so that the objective lens of the imaging unit 12 faces forward and is positioned at approximately the same height as the mounting surface of the cassette tables 18a and 18b.

[0068] Next, the processing unit 58 operates the imaging unit 12 to image one end of the mounting surface of the cassette tables 18a and 18b and the space directly above it (see Figure 6(A)). If the image formed by this imaging (first image) includes the side wall 16c of the cassette 16, the processing unit 58 measures the distance in the Y-axis direction (first distance: I1) between one end of the mounting surface of the cassette tables 18a and 18b and the side wall 16c of the cassette 16 based on the first image.

[0069] On the other hand, if the first image does not include the side wall 16c of the cassette 16, the processing unit 58 moves the transport robot 6 along the Y-axis by a predetermined distance toward the other end of the mounting surface of the cassette table 18a, 18b. This predetermined distance is set to be approximately equal to, for example, the width (length along the Y-axis) of the space included in the image formed by imaging by the imaging unit 12.

[0070] Next, the processing unit 58 operates the imaging unit 12 to image a portion of the mounting surface of the cassette tables 18a and 18b and the space directly above it. If the image formed by this imaging (second image) includes the side wall 16c of the cassette 16, the processing unit 58 measures the first interval I1 based on the first and second images.

[0071] On the other hand, if the second image does not include the side wall 16c of the cassette 16, the movement of the transport robot 6 and imaging by the imaging unit 12 described above are repeated until an image including the side wall 16c of the cassette 16 is formed, after which the processing unit 58 measures the first interval I1.

[0072] Next, the imaging unit 12 is positioned to capture images of the other end of the mounting surface of the cassette tables 18a and 18b and the space directly above it. Specifically, the processing unit 58 operates the Y-axis movement mechanism located inside the opening 4a so that the transport robot 6 is positioned behind the other end of the mounting surface of the cassette tables 18a and 18b.

[0073] Next, the processing unit 58 operates the imaging unit 12 to image the other end of the mounting surface of the cassette tables 18a and 18b and the space directly above it (see Figure 6(B)). If the image formed by this imaging (third image) includes the side wall 16b of the cassette 16, the processing unit 58 measures the distance in the Y-axis direction (second distance: I2) between the other end of the mounting surface of the cassette tables 18a and 18b and the side wall 16b of the cassette 16 based on the third image.

[0074] On the other hand, if the third image does not include the side wall 16c of the cassette 16, the movement of the transport robot 6 toward one end of the mounting surface of the cassette table 18a, 18b and imaging by the imaging unit 12 are repeated until an image (fourth image) including the side wall 16b of the cassette 16 is formed. Once the fourth image is formed, the processing unit 58 measures the second interval I2 based on the third and fourth images.

[0075] Next, the processing unit 58 determines the position of the center of the cassette 16 in the Y-axis direction based on the first interval I1 and the second interval I2. For example, if W is the width of the mounting surface of the cassette tables 18a and 18b stored in the storage unit 60, the position of the center is at a distance of {W + (I1 - I2)} / 2 from one end of the mounting surface of the cassette tables 18a and 18b.

[0076] Then, the processing unit 58 stores data indicating the central position in the storage unit 60 as data indicating the position in the Y-axis direction of the robot hand 14 that is inserted into the cassette 16 when the workpiece 11 is discharged from the cassette 16.

[0077] Next, the imaging unit 12 is positioned to capture images of the center of the mounting surface of the cassette tables 18a and 18b and the space directly above it. Specifically, the processing unit 58 operates the Y-axis movement mechanism located inside the opening 4a so that the transport robot 6 is positioned behind the center of the mounting surface of the cassette tables 18a and 18b.

[0078] Next, the processing unit 58 operates the imaging unit 12 to image the center of the mounting surface of the cassette tables 18a and 18b and the space directly above it (see Figure 6(C)). If the image formed by this imaging (fifth image) includes one or more workpieces 11, the processing unit 58 measures the height of each of the one or more workpieces 11 as seen from the mounting surface of the cassette tables 18a and 18b based on the fifth image.

[0079] Furthermore, if the fifth image does not include the top plate 16a of the cassette 16, the processing unit 58 operates an actuator provided on the first drive unit 8 of the transport robot 6 to raise the imaging unit 12, etc., by a predetermined height. This predetermined height is set, for example, to be equal to the height (length along the Z-axis) of the space included in the image formed by imaging by the imaging unit 12.

[0080] Next, the processing unit 58 operates the imaging unit 12 to image the space directly above the center of the mounting surface of the cassette tables 18a and 18b. If the image formed by this imaging (sixth image) includes one or more workpieces 11, the processing unit 58 measures the height of each of the one or more workpieces 11 as seen from the mounting surface of the cassette tables 18a and 18b, based on the fifth and sixth images.

[0081] Furthermore, if the sixth image does not include the top plate 16a of the cassette 16, the raising of the imaging unit 12 and imaging by the imaging unit 12 are repeated until an image including the top plate 16a of the cassette 16 is formed. Also, if each image formed by repeated imaging includes one or more workpieces 11, the processing unit 58 measures the height of each of the one or more workpieces 11 as viewed from the mounting surface of the cassette tables 18a and 18b.

[0082] Next, the processing unit 58 stores data indicating the offset position from the measured height of one or more workpieces 11 in the storage unit 60 as data indicating the position in the Z-axis direction of the robot hand 14 inserted into the cassette 16 when each workpiece 11 is discharged from the cassette 16. This offset is set to prevent collision between the robot hand 14 inserted into the cassette 16 and the workpieces 11.

[0083] Furthermore, the offset amount is determined, for example, based on an image (side wall image) that includes two or more adjacent grooves 16d in the Z-axis direction from among the multiple grooves 16d formed on the inner surfaces of the side walls 16b, 16c of the cassette 16. Specifically, the processing unit 58 measures the spacing between the multiple grooves 16d in the Z-axis direction based on the side wall image, and then determines the offset amount as a distance of 1 / 4 to 3 / 4 (for example, 1 / 2) times this spacing.

[0084] The sidewall image is formed, for example, by additional imaging performed to determine the offset amount. Alternatively, if any of the first to fourth images above contain two or more grooves 16d, at least one of these images may be used as the sidewall image.

[0085] Next, the workpiece 11 is unloaded from the cassette 16. When unloading the workpiece 11 from the cassette 16, first, the robot hand 14, which is positioned in an appropriate location for unloading the workpiece 11 based on the data stored in the memory unit 60, is inserted into the cassette 16.

[0086] For example, the robot hand 14 is inserted into the cassette 16 in the following order. First, the processing unit 58 rotates the spindle 10e located inside the second drive unit 10d so that the holding surface of the robot hand 14 faces upward.

[0087] Next, the processing unit 58 operates the Y-axis movement mechanism located inside the opening 4a by referring to the data indicating the position of the robot hand 14 in the Y-axis direction stored in the memory unit 60. As a result, the transport robot 6 is positioned behind the center of the cassette 16 in the Y-axis direction.

[0088] Next, the processing unit 58 refers to the data indicating the position of the robot hand 14 in the Z-axis direction stored in the memory unit 60 and controls the actuator provided inside the first drive unit 8 of the transport robot 6 to raise and lower the imaging unit 12, etc. As a result, the holding surface of the robot hand 14 is positioned below the height of the workpiece 11 to be transported by the above-mentioned offset amount.

[0089] Next, the processing unit 58 rotates the first arm 10a, the second arm 10b, and / or the second drive unit 10d by referring to the data indicating the position of the robot hand 14 in the Y-axis direction stored in the memory unit 60. As a result, the robot hand 14 is inserted into the cassette 16 with the center of the holding surface of the robot hand 14 in the Y-axis direction coinciding with the center of the cassette 16 in the Y-axis direction.

[0090] Next, the processing unit 58 controls the actuator provided on the first drive unit 8 to raise the robot hand 14, etc., so that the holding surface of the robot hand 14 contacts and supports the workpiece 11. Then, the processing unit 58 controls the robot hand 14 so that the workpiece 11 is attracted and held by the robot hand 14.

[0091] Next, the processing unit 58 rotates the first arm 10a, the second arm 10b, and the second drive unit 10d so that the workpiece 11 is discharged from the cassette 16. With this, the discharge of the workpiece 11 from the cassette 16 is completed.

[0092] In the conveying device included in the grinding apparatus 2 described above, the position of the robot hand 14 inserted into the cassette 16 when the workpiece 11 is discharged from the cassette 16 is determined by referring to multiple images formed by imaging by the imaging unit 12.

[0093] Therefore, in this conveying device, the operator does not need to know in advance the detailed structure of the cassette 16 or the warping or bending of the workpiece 11 contained in the cassette 16. As a result, the operator's work when unloading the workpiece 11 from the cassette 16 becomes simpler.

[0094] Furthermore, in the conveying device included in the grinding device 2, the imaging unit 12 captures an image of the workpiece 11 contained in the cassette 16 to form an image, and then the workpiece 11 is discharged from the cassette 16. Therefore, in this conveying device, abnormalities in the storage condition of the workpiece 11 in the cassette 16 and abnormalities in the workpiece 11 itself can be easily detected.

[0095] Examples of abnormalities in the storage state of the workpiece 11 in the cassette 16 include, for example, slanted insertion (where the outer edge of the workpiece 11 is supported by grooves 16d of different heights in the side walls 16b and 16c) and double insertion (where the outer edges of two workpieces 11 are supported by grooves 16d of the same height in the side walls 16b and 16c).

[0096] Furthermore, abnormalities in the workpiece 11 itself include, for example, cases where the workpiece 11 has a shape unsuitable for grinding (such as the workpiece 11 being too thick or too thin, or the warping or bending of the workpiece 11 being too great).

[0097] Furthermore, in the grinding device 2, if an abnormality in the storage condition of the workpiece 11 or an abnormality in the workpiece 11 itself is detected, an error message can be notified to the operator, for example, via a touch panel or the like.

[0098] The above description represents only one aspect of the present invention, and the present invention is not limited to the above description. For example, the conveying device included in the grinding apparatus 2 may be provided with one or more light sources used when imaging is performed by the imaging unit 12.

[0099] For example, this transport device may be equipped with light sources that illuminate the cassette 16 placed on the cassette tables 18a and 18b from an oblique angle above, from an oblique angle below, and from an oblique angle to the side. In the transport device, multiple images may be formed by imaging the same area of ​​the cassette 16 with the imaging unit 12 while the cassette 16 is illuminated with light from different light sources.

[0100] Furthermore, the transport device may be equipped with a light source capable of illuminating the cassettes 16 placed on the cassette tables 18a and 18b with light patterns of different shapes. In the transport device, multiple images may be formed by performing imaging of the same area of ​​the cassette 16 by the imaging unit 12 while light patterns of different shapes are illuminating the cassette 16.

[0101] When multiple images are formed by imaging the same area of ​​the cassette 16 under different light irradiation conditions, it becomes easier to understand the three-dimensional structure of the workpiece 11 included in that area in more detail.

[0102] Furthermore, the structures and methods of the embodiments described above can be modified as appropriate without departing from the scope of the present invention. [Explanation of Symbols]

[0103] 2: Grinding equipment 4: Base (4a: Opening) 6: Transport robot 8: First drive unit 10: Transport arm (10a: first arm, 10b: second arm, 10c: second joint) (10d: Second drive unit, 10e: Spindle, 10f: Connecting unit) 11: Workpiece (11a: front side, 11b: back side) 12: Imaging Unit 13: Planned division line 14: Robot Hand 15: Device 16: Cassette (16a: Top panel, 16b, 16c: Side walls) (16d: groove, 16e: connecting member) 18a, 18b: Cassette Table 19: Cassette stopper 20: Position adjustment mechanism (20a: Table, 20b: Pin) 22: Conveying mechanism 24: Turntable 26: Chuck table (26a: Holding surface) 28 :Support structure 30:Z-axis movement mechanism 32: Guide rail 34: Mobile Plate 36: Screw shaft 38: Motor 40: Fixture 42: Grinding Unit 44: Spindle Housing 46: Spindle 48: Mount 50a: First grinding wheel 50b: Second grinding wheel 52: Conveying mechanism 54: Washing unit (54a: Spinner table) 56: Control Unit 58: Processing Unit 60: Storage section

Claims

1. A conveying device comprising: a cassette table having a mounting surface on which a cassette for containing a workpiece is placed, having a pair of opposing side walls, with the outer edge of the cassette positioned in one of a plurality of grooves formed on the inner surface of each of the pair of side walls; a conveying robot for unloading the workpiece from the cassette; and a control unit for controlling the operation of the conveying robot, The transport robot comprises a transport arm having a tip that can move in a first direction perpendicular to the mounting surface and a second direction parallel to the mounting surface, a robot hand disposed at the tip of the transport arm and capable of holding the workpiece, and an imaging unit fixed to the transport arm and capable of imaging the area contained in the cassette placed on the mounting surface. The control unit is, Memory unit and, A conveying device having a storage unit that stores in a storage unit first data indicating a first position determined by referring to one or more first images after imaging the cassette containing the workpiece using the imaging unit to form one or more first images, and second data indicating a second position determined by referring to the multiple second images after imaging different areas of the mounting surface of the cassette table on which the cassette is placed using the imaging unit to form multiple second images, and a processing unit that operates the conveying robot such that the position of the robot hand inserted into the cassette in the first direction becomes the first position and the position in the second direction becomes the second position when the workpiece is discharged from the cassette.

2. The one or more first images include a side wall image formed by imaging a region of the plurality of grooves that includes two or more adjacent grooves in the first direction, The conveying device according to claim 1, wherein the first position is determined by referring to the spacing between the plurality of grooves in the first direction, which is measured with reference to the side wall image.

Images