JP7614709B2 - Conveyor - Google Patents

Description

The present invention relates to a transport device for transporting wafers.

Chips for devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are essential components in various electronic devices such as mobile phones and personal computers. Such chips are manufactured, for example, by dividing a wafer on which a large number of devices are formed into areas containing individual devices.

Wafers on which devices are formed are often thinned before being divided in order to reduce the size and weight of the chips. One method for thinning the wafer is to grind it using a grinding device that has a chuck table that holds the front (lower) side of the wafer by suction with a holding surface, and a grinding wheel that is provided above the chuck table and has multiple grinding stones that are arranged in a circular pattern.

In order to grind wafers in this way, it is necessary to first load the wafers into the grinding machine. For example, in a typical chip manufacturing process, one lot of wafers (approximately 25 wafers) is stored in a cassette, and this cassette is loaded onto the loading surface of a cassette table installed in the grinding machine. In addition, the grinding machine generally has a transport robot (unloading means) for unloading unground wafers from the cassette and loading ground wafers into the cassette (see, for example, Patent Document 1).

JP 2001-284303 A

This transport robot removes the unground wafer from the cassette and transports it, for example, to the support surface of a support table for alignment. Specifically, the transport robot has a robot hand with a holding surface capable of holding the wafer, and its operation is controlled by a control unit provided in the transport robot or the grinding device.

This control unit has, for example, a memory section that stores the position of the support surface of the support table prior to loading the wafer onto the support surface, and a processing section that controls the transport robot to load the wafer into this position. The operation of storing the position of the support surface of the support table in this memory section (teaching operation) is performed, for example, in the following order.

First, the operator visually checks the position of the robot hand of the transport robot and adjusts the position of the robot hand so that it corresponds to the position of the support surface of the support table. The operator then stores the adjusted position of the robot hand in the memory unit as the position of the support surface of the support table.

However, in this type of teaching work, there is a risk that an operator's mistake could cause the holding surface of the robot hand to collide with the support surface of the support table, resulting in damage to the robot hand. In addition, the operator is required to perform the work carefully and accurately, which can be time-consuming and can take a long time.

On the other hand, damage to the robot hand can be prevented by providing a new sensor near the holding surface of the robot hand that issues a warning immediately before the holding surface of the robot hand collides with the support surface of the support table, and by stopping the operation of the transport robot when this warning is issued. However, in this case, there is a risk that the manufacturing costs of the transport robot and the grinding device will increase.

In view of these points, the object of the present invention is to provide a transport device that can simplify the above teaching work by the operator and reduce the time required for the work, without the need for a dedicated sensor to prevent damage to the robot hand of the transport robot.

According to one aspect of the present invention, a cassette table has a mounting surface on which a cassette capable of housing a wafer is placed in each of a plurality of housing surfaces spaced apart in the height direction, a transport robot that transports the wafer from one of the plurality of housing surfaces in which the wafer is housed, a support table having a support surface capable of supporting the wafer, and a control unit having a processing unit that controls the operation of the transport robot, and the transport robot includes a transport arm that is movable in the height direction, a robot hand that is disposed at the tip of the transport arm and has a holding surface capable of holding the wafer, and a control unit that, together with the transport arm, and a non-contact sensor movable in the height direction, and the processing section uses the non-contact sensor to detect the position in the height direction of any of the multiple storage surfaces on which the wafer is stored, and then refers to this position to determine the position in the height direction of the robot hand that is inserted into the cassette when the wafer is removed from the cassette, and the processing section uses the non-contact sensor to detect the position in the height direction of the support surface, and then refers to this position to determine the position in the height direction of the robot hand when the wafer is loaded onto the support surface.

According to another aspect of the present invention, there is provided a cassette table having a plurality of storage surfaces spaced apart in a height direction, each of which has a placement surface on which a cassette capable of accommodating a wafer is placed;
a control unit having a transport robot capable of loading the wafer into any one of the plurality of storage surfaces where the wafer is not stored, a support table having a support surface for supporting the wafer, a storage unit for storing a storage surface among the plurality of storage surfaces where the wafer is to be stored by the transport robot, and a processing unit for controlling the operation of the transport robot, wherein the transport robot includes a transport arm movable in the height direction, a robot hand disposed at a tip of the transport arm and having a holding surface capable of holding the wafer, and a non-contact sensor movable in the height direction together with the transport arm. and a processing section for detecting a position of the support surface in the height direction using the non-contact sensor, and then determining a position of the robot hand in the height direction when transporting the wafer from the support surface by referring to this position, and using the non-contact sensor to confirm that no other wafer is stored on the intended storage surface, and after detecting the position of the intended storage surface in the height direction, determining a position in the height direction of the robot hand to be inserted into the cassette when transporting the wafer into the cassette by referring to this position.

In the present invention, after the non-contact sensor detects the position from which the wafer is to be removed, this position is referenced to determine the position of the robot hand when removing the wafer, and after the non-contact sensor detects the position to which the wafer is to be removed, this position is referenced to determine the position of the robot hand when removing the wafer.

In other words, in the present invention, both the source position and the destination position are identified by a single non-contact sensor. This eliminates the need to provide a dedicated sensor to prevent damage to the robot hand of the transport robot (collision between the holding surface of the robot hand and the support surface of the support table), and also simplifies the above teaching work by the operator, reducing the time required for the work.

FIG. 1 is a perspective view showing a schematic diagram of an example of a grinding apparatus including a transfer device for transferring a wafer. FIG. 2 is a perspective view illustrating an example of a transfer robot. FIG. 3 is a perspective view illustrating an example of a wafer. FIG. 4 is a perspective view showing an example of a cassette. FIG. 5 is a plan view showing a schematic diagram of the turntable and its surrounding structure. 6A to 6C are cross-sectional views that typically show an example of the operation of the transport robot when the processing section stores the position of the support surface in the height direction in the storage section. Figures 7(A) and 7(B) are cross-sectional views showing a schematic example of the operation of the transport robot when the processing unit stores the vertical position of the storage surface in the memory unit, and Figure 7(C) is a cross-sectional view showing a schematic example of the operation of the transport robot when transporting a wafer from the storage surface. 8A and 8B are cross-sectional views that diagrammatically show an example of the operation of the transport robot when the processing unit stores the position of the intended storage surface in the height direction in the storage unit. 9A to 9C are cross-sectional views that typically show an example of the operation of the transport robot when the processing section stores the position of the support surface in the height direction in the storage section.

An embodiment of the present invention will be described with reference to the attached drawings. FIG. 1 is a perspective view showing a schematic example of a grinding device including a transport device for transporting wafers. In FIG. 1, some of the components of the grinding device are shown in functional blocks. In addition, the X-axis direction (front-back 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 perpendicular to the X-axis direction and the Y-axis direction (vertical direction).

The grinding device 2 shown in FIG. 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 is provided within the opening 4a. FIG. 2 is a perspective view that shows the transport robot 6. The transport robot 6 has a cylindrical first drive unit 8 that is fixed to the bottom surface of the opening 4a and extends along the Z-axis direction.

Inside the first drive unit 8, an actuator (not shown) such as an air cylinder that has a piston rod that can move along the Z-axis direction and can rotate around a rotation axis along the Z-axis direction is provided. In addition, an opening through which this piston rod passes is provided on the upper surface side of the first drive unit 8. The transport arm 10 is connected to the upper end of this piston rod.

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

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

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 unit 10c. The lower side of one end of the second drive unit 10d is connected to the upper side of the other end of the second arm unit 10b via the second joint unit 10c in a manner that allows it to rotate around a rotation axis along the Z-axis direction.

A non-contact sensor 12 is provided on one end of the upper surface of the second drive unit 10d to detect structures that exist in the direction from the other end of the second drive unit 10d to the one end of the second drive unit 10d as viewed from the second drive unit 10d. The non-contact sensor 12 is, for example, an optical sensor having a light-projecting unit that projects light (e.g., a laser beam) in this direction and a light-receiving unit that receives light reflected by the structure.

In addition, a motor (not shown) is provided inside the second drive unit 10d to rotate a spindle 10e that can rotate along a direction perpendicular to the Z-axis direction. This spindle 10e passes through an opening provided on the side surface on the other end side of the second drive unit 10d, and its tip is exposed to the outside. In addition, the tip of the spindle 10e is connected to the rectangular parallelepiped base end of the robot hand 14 via a plate-shaped connecting part 10f.

The robot hand 14 also has an elliptical plate-shaped portion that is integrated with its base end. Specifically, this portion has a shape in which the major axis of the ellipse is parallel to the spindle 10e, and this portion has a linear notch that runs from the center to the tip. In addition, one surface of the elliptical plate-shaped portion of the robot hand 14 is provided with, for example, multiple suction holes (not shown).

This suction hole is connected to a suction source (not shown) such as an ejector via a flow path provided inside the robot hand 14 and a valve that controls the flow of gas. By operating the suction source with this valve open, negative pressure is generated on one side of the elliptical plate-shaped portion of the robot hand 14.

Therefore, this surface functions as a holding surface that holds the wafer by suction. In addition, in the transport robot 6, the wafer can be turned upside down by rotating the spindle 10e while the wafer is held by suction on the holding surface of the robot hand 14. In other words, the wafer can be held on either the upper or lower side of the robot hand 14.

Figure 3 is a perspective view showing a schematic example of a wafer transported by a transport robot 6. The wafer 11 shown in Figure 3 is made of a semiconductor material such as silicon (Si). The front surface 11a of the wafer 11 is divided into multiple regions by multiple planned division lines 13 that intersect with each other, and a device 15 such as an IC or LSI is formed in each region.

There are no limitations on the material, shape, structure, size, etc. of the wafer 11. For example, the wafer 11 may be a substrate made of other semiconductor materials, ceramics, resin, metal, etc. Similarly, there are no limitations on the type, number, shape, structure, size, arrangement, etc. of the devices 15.

A film-like tape having a diameter roughly equal to that of the wafer 11 may be attached to the front surface 11a of the wafer 11. This tape is made of, for example, resin, and protects the device 15 by absorbing the impact applied to the front surface 11a when the back surface 11b of the wafer 11 is ground.

Figure 4 is a perspective view showing a typical example of a cassette that contains wafers 11. The cassette 16 shown in Figure 4 has a flat top plate 16a. This top plate 16a has a shape in which a pair of adjacent corners out of the four corners of a rectangular flat plate are chamfered, and the remaining pair of corners remain unchamfered. The upper end of a sidewall (not shown) extending in a direction perpendicular to the top plate 16a (height direction) is fixed to the underside of the end (rear end) located between the pair of chamfered portions of the top plate 16a.

The upper ends of side walls 16b, 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 non-chamfered corner of the tabletop 16a. On the other hand, no side wall extending in the height direction is fixed to the underside of the end (front end) located between a pair of non-chamfered corners of the tabletop 16a. In other words, the underside of the front end of the tabletop 16a is open.

The inner surfaces of the side walls 16b and 16c are provided with wafer support grooves 16d at a predetermined interval in the height direction and along a direction perpendicular to the height direction. Specifically, each of the multiple wafer support grooves 16d provided on the inner surface of the side wall 16b is provided to face one of the multiple wafer support grooves 16d provided on the inner surface of the side wall 16c.

The cross-sectional shape of the wafer support groove 16d in a plane perpendicular to the top plate 16a and the side walls 16b and 16c is generally rectangular. In other words, the wafer support groove 16d has a pair of inner side surfaces that are generally perpendicular to the height direction, and a bottom surface that is generally parallel to the height direction.

Then, in the cassette 16, the wafer 11 is stored in a state in which the wafer 11 is placed on the inner surface of the wafer support groove 16d that is farther from the top plate 16a. In other words, the plane including the inner surface of the pair of opposing wafer support grooves 16d that is farther from the top plate 16a becomes the storage surface that stores the wafer 11.

The lower part of side wall 16b and the lower part of side wall 16c are connected via a long, thin, plate-like connecting member 16e. The cassette 16 is then loaded into the grinding device 2 shown in FIG. 1, for example, in a state in which it contains a number of unground wafers 11 or in an empty state in which it can contain ground wafers 11.

Specifically, the cassette 16 is placed on the generally flat placement surfaces of the cassette tables 18a and 18b so that the open surface without side walls is positioned on the opening 4a side. There is no limit to the number of wafer support grooves 16d provided 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 wafer support grooves 16d corresponding to one lot of wafers 11 (approximately 25 wafers).

The remaining components of the grinding device 2 will now be described with reference to FIG. 1 again. A position adjustment mechanism 20 for adjusting the position of the wafer 11 is provided diagonally behind the transport robot 6. The position adjustment mechanism 20 includes, for example, a disk-shaped table (support table) 20a having an upper surface (support surface) capable of supporting the wafer 11, and a number of pins 20b arranged around the table 20a.

When the wafer 11 removed from the cassette 16 by the transport robot 6 is loaded onto the support surface of the table 20a, the pins 20b move along the radial direction of the table 20a so as to contact the outer periphery of the wafer 11. This causes the center of the wafer 11 to be aligned to a predetermined position in the X-axis direction and the Y-axis direction. Details of the transport of the wafer 11 from the cassette 16 to the table 20a by the transport robot 6 will be described later.

A transport mechanism 22 that holds the wafer 11 and transports it backward is provided diagonally behind the position adjustment mechanism 20 (behind the transport robot 6). The transport mechanism 22 includes a holding pad that holds the wafer 11 by suction, and an arm connected to the holding pad. The transport mechanism 22 then rotates the holding pad with the arm, thereby transporting the wafer 11, whose position has been adjusted by the position adjustment mechanism 20, backward.

A disk-shaped turntable 24 is provided behind the transport mechanism 22. The turntable 24 is connected to a rotary drive source (not shown) such as a motor, and rotates around an axis of rotation roughly parallel to the Z-axis direction. Three chuck tables 26 capable of holding the wafer 11 are provided on the upper surface of the turntable 24.

The three chuck tables 26 are provided at approximately equal intervals along the circumferential direction of the turntable 24. There is no limit to the number of chuck tables 26 provided on the turntable 24. Figure 5 is a plan view that shows a schematic diagram of the turntable 24 and its surrounding structure.

For ease of explanation, some components are shown with dashed lines in FIG. 5. The transport mechanism 22 transports the wafer 11 held by the holding pad to the chuck table 26 arranged in the loading/unloading area A (see FIG. 5) adjacent to the transport mechanism 22. The turntable 24 rotates, for example, in the direction indicated by the arrow in FIG. 1 and FIG. 5, and moves each chuck table 26 from the loading/unloading area A to the rough grinding area B to the finish grinding area C in that order.

Each chuck table 26 is connected to a rotary 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 disk-shaped frame made of a metal material such as stainless steel. A recess with a circular opening at the top end is formed on the upper surface of this frame, and a disk-shaped porous plate made of ceramics or the like is fixed in this recess.

The upper surface of the chuck table 26 is configured in a shape equivalent to the side of a cone whose center protrudes slightly beyond the outer edge, and functions as a holding surface 26a that holds the wafer 11. In other words, the chuck table 26 has a holding surface 26a at its upper part that holds the wafer 11.

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 wafer 11 loaded onto the chuck table 26 is sucked in by the negative pressure of the suction source acting on the holding surface 26a.

As shown in FIG. 1, a columnar support structure 28 is 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 side of the support structure 28 and has a pair of guide rails 32 that extend along the Z-axis direction.

A moving plate 34 is connected to the front side of the 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 disposed between the pair of guide rails 32. A motor 38 for rotating the screw shaft 36 is connected to one end of the screw shaft 36.

A nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 36 is provided on the surface of the screw shaft 36 where the helical grooves are formed, forming a ball screw. In other words, when the screw shaft 36 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Z-axis direction. In addition, this nut portion is fixed to the rear surface (back surface) side of the moving plate 34.

Therefore, when the screw shaft 36 is rotated by the 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 portion. In addition, a fixture 40 is provided on the front (surface) side of the movable plate 34. A grinding unit 42 for grinding the wafer 11 is supported on the fixture 40. The grinding unit 42 includes a spindle housing 44 fixed to the fixture 40.

The spindle 46, which rotates around a rotation axis along the Z-axis direction, is housed in the spindle housing 44 in a rotatable manner. The lower end of the spindle 46 is exposed from the lower end surface of the spindle housing 44. A disk-shaped mount 48 is fixed to the exposed lower end of the spindle 46.

A first grinding wheel 50a for rough grinding is attached to the underside of the mount 48 of the grinding unit 42 on the rough grinding area B side. The first grinding wheel 50a for rough grinding has a first wheel base made of a metal such as stainless steel or aluminum and formed to have approximately the same diameter as the mount 48.

A number of first grinding wheels, each made of abrasive grains such as diamond suitable for rough grinding, fixed with a bond such as vitrified or resinoid, are arranged in a ring shape on the underside of the first wheel base. In addition, the spindle housing 44 of the grinding unit 42 on the rough grinding area B side contains a first rotation drive source (not shown) such as a motor connected to the upper end side of the spindle 46.

The first grinding wheel 50a rotates together with the spindle 46 due to the power of the first rotary drive source. A liquid supply nozzle (not shown) is provided next to the first grinding wheel 50a, which can supply liquid (grinding fluid) such as pure water to the portion (processing point) where the wafer 11 and the first grinding wheel come into contact. However, instead of or together with this liquid supply nozzle, a liquid supply port used to supply liquid may be provided on the first grinding wheel 50a.

Similarly, a second grinding wheel 50b for finish grinding is attached to the underside of the mount 48 of the grinding unit 42 on the finish grinding area C side. The second grinding wheel 50b for finish grinding has a second wheel base made of a metal such as stainless steel or aluminum and formed to have approximately the same diameter as the mount 48.

A number of second grinding wheels, each made 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 underside of the second wheel base. In addition, the spindle housing 44 of the grinding unit 42 on the finish grinding area C side contains a second rotation drive source (not shown) such as a motor connected to the upper end side of the spindle 46.

The second grinding wheel 50b rotates together with the spindle 46 due to the power of the second rotary drive source. A liquid supply nozzle (not shown) is provided next to the second grinding wheel 50b, which can supply liquid (grinding fluid) such as pure water to the portion (processing point) where the wafer 11 and the second grinding wheel come into contact. However, instead of or together with this liquid supply nozzle, a liquid supply port used to supply liquid may be provided on the second grinding wheel 50b.

The wafers 11 held on each chuck table 26 are ground in sequence by the two grinding units 42 described above. Specifically, the wafers 11 held on the chuck tables 26 in the rough grinding area B are ground by the grinding units 42 on the rough grinding area B side, and the wafers 11 held on the chuck tables 26 in the finish grinding area C are ground by the grinding units 42 on the finish grinding area C side.

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 wafer 11 and transports it forward. The transport mechanism 52 has a holding pad that holds the wafer 11 by suction, and an arm connected to the holding pad. The transport mechanism 52 then transports the ground wafer 11 forward from the chuck table 26 by rotating the holding pad with the arm.

A cleaning unit 54 is provided in front of the transport mechanism 52 to clean the wafer 11 carried out by the transport mechanism 52. The cleaning unit 54 has, for example, an upper surface (support surface) capable of supporting the wafer 11, a spinner table (support table) 54a that rotates while holding the wafer 11 on this support surface, and a nozzle (not shown) that sprays a cleaning fluid onto the wafer 11 held by the spinner table 54a.

The wafer 11 cleaned in the cleaning unit 54 is removed from the spinner table 54a by the transport robot 6 and loaded into the cassette 16. Details of the transport of the wafer 11 from the spinner table 54a to the cassette 16 by the transport robot 6 will be described later.

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 has, 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, programs, etc.) used in the processing unit 58.

The functions of the processing unit 58 are realized by a CPU (Central Processing Unit) that reads and executes programs stored in the memory unit 60. The functions of the memory unit 60 are realized by at least one of semiconductor memories such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), and NAND flash memory, and magnetic storage devices such as HDD (Hard Disk Drive).

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

The grinding device 2 shown in FIG. 1 can also be described as having a transport device centered around the transport robot 6. Specifically, this transport device includes the transport robot 6 that transports the wafers 11, cassette tables 18a and 18b having a mounting surface on which a cassette 16 that contains the wafers 11 is placed, a position adjustment mechanism 20 having a table 20a that supports the wafers 11, a cleaning unit 54 having a spinner table 54a that supports the wafers 11, and a control unit 56 that controls the transport robot 6.

Below, an example of the operation of the transport robot 6 when unground wafer 11 is removed from cassette 16 and transferred to table 20a will be described with reference to Figures 6(A) to 6(C) and Figures 7(A) to 7(C). Note that Figures 6(A) to 6(C) are cross-sectional views that show a schematic example of the operation of the transport robot 6 when processing unit 58 stores the position of the support surface of table 20a in the height direction in memory unit 60.

FIG. 7(A) and FIG. 7(B) are cross-sectional views that show an example of the operation of the transport robot 6 when the processing unit 58 stores in the memory unit 60 the position in the height direction of the storage surface of the cassette 16 in which the wafer 11 is stored. FIG. 7(C) is a cross-sectional view that shows an example of the operation of the transport robot 6 when the wafer 11 is removed from the storage surface of the cassette 16 in which the wafer 11 is stored.

When the unground wafer 11 is removed from the cassette 16 and loaded onto the table 20a, the processing unit 58 performs an operation (teaching operation) to store the position of the support surface of the table 20a in the memory unit 60.

In this teaching operation, first, the processing unit 58 adjusts the state of the transport arm 10 so that the table 20a is positioned in a direction in which the non-contact sensor 12 of the transport robot 6 can detect the structure (e.g., the direction from the robot hand 14 toward the second drive unit 10d). Specifically, the processing unit 58 rotates the first arm 10a, the second arm 10b, and the second drive unit 10d (see FIG. 6(A)).

Next, the processing unit 58 raises the non-contact sensor 12 of the transport robot 6 to a position where the top surface (support surface) of the table 20a is not detected by the non-contact sensor 12. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise the piston rod 62. Then, the processing unit 58 starts detection of the structure by the non-contact sensor 12 (e.g., projecting a laser beam) (see FIG. 6B).

Next, while the non-contact sensor 12 continues to detect the structure, the processing unit 58 lowers the non-contact sensor 12. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to lower the piston rod 62. Then, when the support surface of the table 20a is detected, the processing unit 58 stops the operation of the actuator (see FIG. 6(C)).

Next, the processing unit 58 stores the position of the support surface of the table 20a in the height direction in the memory unit 60. This completes the process of the processing unit 58 storing the position of the support surface of the table 20a in the memory unit 60 (teaching process).

Next, the processing unit 58 adjusts the state of the transport arm 10 so that the cassette tables 18a, 18b are positioned in a direction in which the non-contact sensor 12 of the transport robot 6 can detect the structure (e.g., the direction from the robot hand 14 toward the second drive unit 10d). Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to lower the piston rod 62 and rotate the first arm 10a, the second arm 10b, and the second drive unit 10d (see FIG. 7(A)).

At this time, the state of the transport arm 10 is adjusted so that, in a plan view, the inner surfaces of the side walls 16b, 16c of the cassette 16 are positioned in a direction that allows the non-contact sensor 12 to detect the structure. In other words, the transport arm 10 is adjusted to a state where the wafer support groove 16d and the wafer 11 supported in the wafer support groove 16d can be detected when the non-contact sensor 12 is raised.

Next, the processing unit 58 starts detecting the structure by the non-contact sensor 12 (e.g., projecting a laser beam). Next, the processing unit 58 raises the non-contact sensor 12 until all of the wafer support grooves 16d are detected by the non-contact sensor 12. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise the piston rod 62 (see FIG. 7(B)).

At this time, if the non-contact sensor 12 detects the wafer support groove 16d, the processing unit 58 stores in the memory unit 60 information indicating which step from the bottom the detected wafer support groove 16d is located at (the step number of the wafer support groove 16d), the height position of the storage surface capable of storing the wafer 11 (the plane including the inner surface of the wafer support groove 16d that is farther from the top plate 16a), and the presence or absence of the wafer 11 on this storage surface.

The number of stages of the wafer support grooves 16d is the value when counting up from the wafer support groove 16d located lowest in the height direction among the multiple wafer support grooves 16d contained in the cassette 16. For convenience, the wafers 11 are generally stored in the same number of wafer support grooves 16d of the cassette 16 before and after grinding.

Therefore, the number of stages of the wafer support groove 16d stored in the memory unit 60 is used, for example, to identify the wafer support groove 16d (planned storage surface) in which the wafer 11 will be accommodated after it has been ground. In other words, when the number of stages of the wafer support groove 16d that accommodates the wafer 11 is stored in the memory unit 60, the number of stages of the wafer support groove 16d (planned storage surface) in which the wafer 11 will be accommodated after it has been ground is stored in the memory unit 60.

Next, when the non-contact sensor 12 detects the top plate 16a of the cassette 16, the processing unit 58 stops the operation of the actuator. This completes the process of detecting the height position of the storage surface capable of storing the wafers 11.

Next, the processing unit 58 determines the heightwise position of the robot hand 14 to be inserted into the cassette 16 by referring to the heightwise position of the storage surface that stores the wafer 11 stored in the memory unit 60. Specifically, the processing unit 58 determines the heightwise position of the robot hand 14 to be inserted into the cassette 16 so that the position of the upward-facing holding surface of the robot hand 14 is slightly lower than the position of the storage surface that stores the wafer 11 stored in the memory unit 60.

Next, the processing unit 58 adjusts the state of the transport arm 10 so that the robot hand 14 is inserted into the cassette 16 at the determined position in the height direction. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise or lower the piston rod 62, and rotates the first arm 10a, the second arm 10b, and the second drive unit 10d to insert the robot hand 14 into the cassette 16 (see FIG. 7(C)).

Next, the processing unit 58 adjusts the height position of the robot hand 14 so that the height position of the upward-facing holding surface of the robot hand 14 is slightly higher than the height position of the storage surface that stores the wafer 11 stored in the memory unit 60. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise the piston rod 62.

Next, the processing unit 58 controls the robot hand 14 so that the wafer 11 is held by suction on the robot hand 14. Next, the processing unit 58 adjusts the state of the transport arm 10 so that the wafer 11 is transferred from the cassette 16 to the table 20a. Specifically, the processing unit 58 first rotates the first arm 10a, the second arm 10b, and the second drive unit 10d to transfer the wafer 11 from the cassette 16.

Then, the processing unit 58 rotates the spindle 10e to turn the robot hand 14 and the wafer 11 upside down. This causes the wafer 11 to be held by suction on the underside of the robot hand 14. The processing unit 58 then rotates the first arm 10a, the second arm 10b, and the second drive unit 10d to position the wafer 11 above the table 20a.

Next, by referring to the height position of the support surface of table 20a stored in memory 60, processing unit 58 determines the height position of robot hand 14 when loading wafer 11 onto this support surface. For example, processing unit 58 determines the height position of robot hand 14 when loading wafer 11 onto this support surface so that the height position of the underside of wafer 11 coincides with the height position of support surface of table 20a stored in memory 60.

Then, the processing unit 58 adjusts the state of the transport arm 10 so that the robot hand 14 is positioned at the determined position in the height direction. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to lower the piston rod 62. Next, the processing unit 58 controls the robot hand 14 so that the robot hand 14 stops suction holding of the wafer 11.

This completes the transfer of the wafer 11 from the storage surface of the cassette 16 to the support surface of the table 20a. Note that in the operation of the transfer robot 6 described above, the teaching work is performed before the wafer 11 is removed from the cassette 16, but the teaching work may be performed after the wafer 11 is removed from the cassette 16 and before the wafer 11 is transferred onto the table 20a.

Below, an example of the operation of the transport robot 6 when transferring the ground wafer 11 from the spinner table 54a to the cassette 16 will be described with reference to Figures 8(A) and 8(B) and Figures 9(A) to 9(C).

FIG. 8(A) and FIG. 8(B) are cross-sectional views that show an example of the operation of the transport robot 6 when the processing unit 58 stores in the memory unit 60 the height position of the storage surface (planned storage surface) that stores the ground wafer 11 among the multiple storage surfaces included in the cassette 16.

In addition, Figures 9(A) to 9(C) are cross-sectional views that show an example of the operation of the transport robot 6 when the processing unit 58 stores the position of the support surface of the spinner table 54a in the height direction in the memory unit 60.

When the ground wafer 11 is transferred from the spinner table 54a to the cassette 16, the processing unit 58 first adjusts the state of the transfer arm 10 so that the cassette tables 18a, 18b are positioned in a direction in which the non-contact sensor 12 of the transfer robot 6 can detect the structure (e.g., the direction from the robot hand 14 toward the second drive unit 10d). Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to lower the piston rod 62 and rotate the first arm 10a, the second arm 10b, and the second drive unit 10d (see FIG. 8(A)).

At this time, the state of the transport arm 10 is adjusted so that, in a plan view, the inner surfaces of the side walls 16b, 16c of the cassette 16 are positioned in a direction that allows the non-contact sensor 12 to detect the structure. In other words, the transport arm 10 is adjusted to a state where the wafer support groove 16d can be detected when the non-contact sensor 12 is raised.

Next, the processing unit 58 starts detection of the structure by the non-contact sensor 12 (e.g., projecting a laser beam). Next, while continuing detection of the structure by the non-contact sensor 12, the processing unit 58 raises the non-contact sensor 12. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise the piston rod 62 (see FIG. 8(B)).

At this time, the processing unit 58 raises the non-contact sensor 12 until it reaches the number of stages (intended storage surface) of the wafer support grooves 16d stored in the memory unit 60 among the multiple wafer support grooves 16d contained in the cassette 16. The processing unit 58 then checks whether another wafer is stored on this intended storage surface.

If it is confirmed that no other wafer is being accommodated on this intended storage surface, the processing unit 58 stores the position of the intended storage surface in the height direction in the memory unit 60. On the other hand, if it is confirmed that another wafer is being accommodated on this intended storage surface, the processing unit 58 controls, for example, a display or the like provided on the grinding device 2 to notify the operator of an error message.

When the height position of the intended storage surface is stored in the memory unit 60, the processing unit 58 adjusts the state of the transport arm 10 so that the spinner table 54a is positioned in a direction in which the non-contact sensor 12 of the transport robot 6 can detect the structure (e.g., the direction from the robot hand 14 toward the second drive unit 10d). Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to lower the piston rod 62 and rotate the first arm 10a, the second arm 10b, and the second drive unit 10d (see FIG. 9(A)).

Next, the processing unit 58 raises the non-contact sensor 12 to a position where the top surface (support surface) of the spinner table 54a is not detected by the non-contact sensor 12 of the transport robot 6. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise the piston rod 62. Then, the processing unit 58 starts detection of the structure by the non-contact sensor 12 (e.g., projecting a laser beam) (see FIG. 9(B)).

Next, while the non-contact sensor 12 continues to detect the structure, the processing unit 58 lowers the non-contact sensor 12. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to lower the piston rod 62. Then, when the support surface of the spinner table 54a is detected, the processing unit 58 stops the operation of the actuator (see FIG. 9(C)).

Next, the processing unit 58 stores the position of the support surface of the spinner table 54a in the height direction in the memory unit 60. Next, by referring to this position, the processing unit 58 determines the position of the robot hand 14 in the height direction when transferring the wafer 11 from this support surface.

For example, the processing unit 58 determines the height position of the robot hand 14 when transporting the wafer 11 from the support surface so that the height position of the downward-facing holding surface of the robot hand 14 coincides with the height position of the upper surface of the wafer 11 supported on the support surface of the spinner table 54a.

Then, the processing unit 58 controls the transport mechanism 52, etc. so that the ground wafer 11 is loaded onto the support surface of the spinner table 54a. The processing unit 58 then adjusts the state of the transport arm 10 so that the robot hand 14 is positioned above the wafer 11. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise the piston rod 62 and rotate the first arm 10a, the second arm 10b, and the second drive unit 10d.

Then, the processing unit 58 controls the actuator provided in the first driving unit 8 to lower the piston rod 62 so that the robot hand 14 is positioned at the determined position in the height direction. The processing unit 58 then controls the robot hand 14 so that the wafer 11 is held by suction on the robot hand 14.

Then, the processing unit 58 adjusts the state of the transport arm 10 so that the wafer 11 is transferred from the spinner table 54a to the cassette 16. Specifically, the processing unit 58 first controls the actuator provided in the first drive unit 8 to raise the piston rod 62, and rotates the first arm 10a, the second arm 10b, and the second drive unit 10d to transfer the wafer 11 from the spinner table 54a.

Next, the processing unit 58 rotates the spindle 10e to turn the robot hand 14 and the wafer 11 upside down. This causes the wafer 11 to be held by suction on the upper side of the robot hand 14.

Next, the processing unit 58 determines the heightwise position of the robot hand 14 to be inserted into the cassette 16 by referring to the heightwise position of the intended storage surface stored in the memory unit 60. Specifically, the processing unit 58 determines the heightwise position of the robot hand 14 to be inserted into the cassette 16 so that the position of the upward-facing holding surface of the robot hand 14 is slightly higher than the position of the intended storage surface stored in the memory unit 60.

Then, the processing unit 58 adjusts the state of the transport arm 10 so that the robot hand 14 is inserted into the cassette 16 at the determined position in the height direction. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to raise or lower the piston rod 62, and rotates the first arm 10a, the second arm 10b, and the second drive unit 10d to insert the robot hand 14 into the cassette 16.

Next, the processing unit 58 adjusts the height position of the robot hand 14 so that the height position of the upward-facing holding surface of the robot hand 14 coincides with the height position of the intended storage surface stored in the memory unit 60. Specifically, the processing unit 58 controls the actuator provided in the first drive unit 8 to lower the piston rod 62.

Next, the processing unit 58 controls the robot hand 14 to stop suction holding of the wafer 11 by the robot hand 14. This completes the transfer of the wafer 11 from the support surface of the spinner table 54a to the intended storage surface of the cassette 16.

In the operation of the transport robot 6 described above, it was checked whether another wafer was stored on the intended storage surface of the cassette 16 before the wafer 11 was removed from the spinner table 54a. However, this check may be performed after the wafer 11 is removed from the spinner table 54a and before the wafer 11 is loaded into the cassette 16.

In the transport device included in the grinding device 2 described above, the non-contact sensor 12 detects the position of the wafer 11's source (the storage surface of the cassette 16 or the support surface of the spinner table 54a), and then the position of the robot hand 14 when transporting the wafer 11 is determined by reference to this position after detecting the wafer 11's destination (the support surface of the table 20a or the intended storage surface of the cassette 16). Also, after the non-contact sensor 12 detects the wafer 11's destination (the support surface of the table 20a or the intended storage surface of the cassette 16), the position of the robot hand 14 when transporting the wafer 11 is determined by reference to this position.

That is, in this transport device, both the source position and the destination position are identified by a single non-contact sensor 12. This eliminates the need to provide a dedicated sensor to prevent damage to the robot hand 14 of the transport robot 6 (collision between the holding surface of the robot hand 14 and the support surface of the table 20a or spinner table 54a), and also simplifies the above teaching work by the operator, reducing the time required for the work.

The above-mentioned transport device is one aspect of the present invention, and the transport device of the present invention is not limited to the above-mentioned transport device. For example, in the above-mentioned transport device, the non-contact sensor 12 is provided on one end side of the upper surface of the second drive unit 10d of the transport arm 10, but the installation position of the non-contact sensor 12 is not limited. For example, the non-contact sensor 12 may be provided on the upper surface of the plate-shaped connecting unit 10f.

In addition, in the above-mentioned transport device, a non-contact sensor 12 is provided that detects structures present in a direction from the other end of the second drive unit 10d toward one end (a direction from the robot hand 14 toward the second drive unit 10d), but this direction is not limited. For example, the non-contact sensor 12 may be configured to detect structures present in a direction from one end of the second drive unit 10d toward the other end (a direction from the second drive unit 10d toward the robot hand 14).

In addition, in the above-mentioned transfer device, both the transfer of the unground wafer 11 from the cassette 16 to the table 20a and the transfer of the ground wafer 11 from the spinner table 54a to the cassette 16 are performed by a single transfer robot 6, but these transfers may be performed by separate transfer robots 6.

Although the above-mentioned conveying device is included in the grinding device 2, the conveying device of the present invention may be included in a device other than the grinding device 2, or may be an independent device. For example, the conveying device of the present invention may be included in a semiconductor manufacturing device such as a cutting device or a laser processing device.

In addition, the structures and methods of the above-described embodiments can be modified as appropriate without departing from the scope of the present invention.

2: Grinding device 4: Base (4a: opening)
6: Transport robot 8: First drive unit 10: Transport arm (10a: first arm, 10b: second arm)
(10c: second joint portion, 10d: second drive portion)
(10e: spindle, 10f: connecting part)
12: Non-contact sensor 14: Robot hand 11: Wafer (11a: front surface, 11b: back surface)
13: Planned division line 15: Device 16: Cassette (16a: top plate, 16b, 16c: side walls)
(16d: wafer support groove, 16e: connection member)
18a, 18b: cassette table 20: position adjustment mechanism (20a: table (support table), 20b: pin)
22: Transport mechanism 24: Turntable 26: Chuck table (26a: holding surface)
28: Support structure 30: Z-axis movement mechanism 32: Guide rail 34: Movement 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: Transport mechanism 54: Cleaning unit (54a: Spinner table)
56: Control unit 58: Processing unit 60: Storage unit

Claims (2)

a cassette table having a plurality of storage surfaces spaced apart in a height direction, each of which has a placement surface on which a cassette capable of accommodating a wafer is placed;
a transfer robot that takes out the wafer from any one of the plurality of storage surfaces in which the wafer is stored;
a support table having a support surface capable of supporting the wafer;
A control unit having a processing unit for controlling an operation of the transport robot,
The transport robot includes:
A transfer arm that is movable in the height direction;
a robot hand disposed at a tip of the transfer arm and having a holding surface capable of holding the wafer;
a non-contact sensor that is movable in the height direction together with the transport arm;
The processing unit includes:
using the non-contact sensor to detect the position in the height direction of any one of the plurality of storage surfaces in which the wafer is stored, and then, by referring to this position, determine the position in the height direction of the robot hand to be inserted into the cassette when carrying the wafer out of the cassette; and
A conveying device that uses the non-contact sensor to detect the position of the support surface in the height direction, and then uses this position as a reference to determine the position of the robot hand in the height direction when transporting the wafer onto the support surface. a cassette table having a plurality of storage surfaces spaced apart in a height direction, each of which has a placement surface on which a cassette capable of accommodating a wafer is placed;
a transfer robot capable of loading the wafer into any one of the plurality of storage surfaces in which the wafer is not stored;
a support table having a support surface for supporting the wafer;
a control unit including a storage unit that stores a storage surface on which the wafer is to be stored by the transport robot among the plurality of storage surfaces, and a processing unit that controls an operation of the transport robot;
The transport robot includes:
A transfer arm that is movable in the height direction;
a robot hand disposed at a tip of the transfer arm and having a holding surface capable of holding the wafer;
a non-contact sensor that is movable in the height direction together with the transport arm;
The processing unit includes:
using the non-contact sensor to detect the position of the support surface in the height direction, and then determining the position of the robot hand in the height direction when carrying the wafer out of the support surface by referring to the position; and
A conveying device that uses the non-contact sensor to confirm that no other wafer is being stored on the intended storage surface, and detects the position of the intended storage surface in the height direction, and then uses this position to determine the height direction position of the robot hand that will be inserted into the cassette when transporting the wafer into the cassette.

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