JP7744232B2 - Grinding device, program, non-transitory recording medium, and grinding device control method - Google Patents

Description

The present invention relates to a grinding device used to grind workpieces such as wafers, a program used to control the grinding device, a non-transitory recording medium on which the program is stored, and a method for controlling the grinding device.

In order to create small, lightweight device chips, there are increasing opportunities to thin wafers with integrated circuits or other devices mounted on their front side. For example, the front side of the wafer is held by the holding surface of a chuck table, and the chuck table and a grinding wheel with abrasive grains attached to it are rotated relative to each other. A liquid (grinding fluid) such as pure water is supplied while the grinding wheel is pressed against the back side of the wafer, thereby thinning the wafer.

When grinding workpieces such as wafers using the above-mentioned method, a process called self-grinding is performed, in which the holding surface of the chuck table is ground (see, for example, Patent Document 1). In this self-grinding process, the holding surface is ground with a grinding wheel (grinding stone) in the same way as the workpiece. Therefore, when the workpiece is held on the holding surface after self-grinding, the distance between the grinding wheel and the holding surface becomes roughly constant throughout the entire area where the workpiece and grinding wheel come into contact, and the workpiece is ground so that its overall thickness is roughly constant.

JP 2008-87104 A

In general, chuck tables used to grind workpieces hold the workpiece by applying suction force from the negative pressure generated by a suction source to the workpiece through tiny holes in the holding surface. However, as grinding of the workpiece progresses, the holes in the holding surface can become clogged with debris generated from the workpiece, reducing the force holding the workpiece. Therefore, the self-grinding described above is performed at any time before the holes in the holding surface become clogged with debris, removing any debris adhering to the holding surface.

However, this self-grinding is performed based on the operator's instructions, and is not always performed at the appropriate time. For example, if the operator forgets to perform the self-grinding and the holes in the holding surface become clogged with debris, the workpiece will no longer be held securely by the chuck table, which will have a negative impact on the grinding of the workpiece.

Therefore, an object of the present invention is to provide a grinding device etc. that prevents the operator from forgetting to perform self-grinding.

According to one aspect of the present invention, a grinding apparatus includes a chuck table having a holding surface for holding a workpiece and rotatable about a rotation axis intersecting the holding surface, a grinding unit having a spindle that can rotate about an axis with a grinding wheel attached to its tip, a movement mechanism that moves the chuck table and the grinding unit relatively in a direction intersecting the holding surface, a control unit having a processing device and a memory device and controlling the chuck table, the grinding unit, and the movement mechanism in accordance with a program stored in the memory device, and an input device that inputs commands to the control unit, the program being read from the input device. and a procedure for grinding the holding surface with the grinding wheel by moving the grinding unit and the chuck table relative to each other by the moving mechanism while the chuck table and the spindle are rotating, after a command to stop the operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit, before the procedure for stopping the operation of the grinding device is completed.

According to another aspect of the present invention, there is provided a program for use in controlling a grinding apparatus, the program comprising: a chuck table having a holding surface for holding a workpiece and rotatable about a rotation axis intersecting the holding surface; a grinding unit having a spindle that can rotate about an axis with a grinding wheel attached to its tip; a movement mechanism that moves the chuck table and the grinding unit relatively in a direction intersecting the holding surface; a control unit having a processing device and a storage device, the control unit controlling the chuck table, the grinding unit, and the movement mechanism in accordance with a program stored in the storage device; and an input device for inputting commands to the control unit, the input device a program for causing the control unit to execute the following steps: a procedure for stopping the operation of the grinding device after a command to stop the operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit; and a procedure for moving the grinding unit and the chuck table relatively by the moving mechanism while the chuck table and the spindle are rotating, and grinding the holding surface with the grinding wheel, before the procedure for stopping the operation of the grinding device is completed after a command to stop the operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit.

Preferably, the program causes the control unit to execute a procedure of adjusting the angle between the rotation axis of the chuck table and the axis of the spindle after a command to stop the operation of the grinding apparatus so that the grinding apparatus is shut down is input to the control unit from the input device, and before the procedure of grinding the holding surface with the grinding wheel is started. Also preferably, the program causes the control unit to execute a procedure of grinding the holding surface with the grinding wheel without causing the control unit to execute a procedure of replacing the grinding wheel attached to the spindle after a command to stop the operation of the grinding apparatus so that the grinding apparatus is shut down is input to the control unit from the input device. Also preferably, the program causes the control unit to execute a procedure of stopping the operation of the grinding apparatus and a procedure of grinding the holding surface with the grinding wheel so that the procedure of grinding the holding surface with the grinding wheel is completed before the procedure of stopping the operation of the grinding apparatus is completed.

According to yet another aspect of the present invention, a non-transitory storage medium on which the program is stored is provided.

According to yet another aspect of the present invention, there is provided a method for controlling a grinding apparatus, the method comprising: a chuck table having a holding surface for holding a workpiece and rotatable about a rotation axis intersecting the holding surface; a grinding unit having a spindle that can rotate about an axis with a grinding wheel attached to its tip; a movement mechanism that relatively moves the chuck table and the grinding unit in a direction intersecting the holding surface; a control unit having a processing device and a storage device and that controls the chuck table, the grinding unit, and the movement mechanism in accordance with a program stored in the storage device; and an input device that inputs commands to the control unit, the input device inputting commands to the control unit when the grinding apparatus is in a shut-down state. a step of inputting a command to stop the operation of the grinding device so that the grinding device is in a shut-down state, after the command to stop the operation of the grinding device is input from the input device to the control unit so that the grinding device is in a shut-down state, stopping the operation of the grinding device; and a step of moving the grinding unit and the chuck table relatively by the moving mechanism while the chuck table and the spindle are rotating, and grinding the holding surface with the grinding wheel, after the command to stop the operation of the grinding device is input from the input device to the control unit so that the grinding device is in a shut-down state, before the step of stopping the operation of the grinding device is completed.

Preferably, the method further includes a step of adjusting the angle between the rotation axis of the chuck table and the axis of the spindle after a command to stop operation of the grinding apparatus so that the grinding apparatus is shut down is input to the control unit from the input device, and before the step of grinding the holding surface with the grinding wheel is started. Also, preferably, after a command to stop operation of the grinding apparatus so that the grinding apparatus is shut down is input to the control unit from the input device, the step of grinding the holding surface with the grinding wheel is performed without performing a step of replacing the grinding wheel attached to the spindle. Also, preferably, the step of grinding the holding surface with the grinding wheel is completed before the step of stopping operation of the grinding apparatus is completed.

In the grinding device, program, and grinding device control method of the present invention, the control unit executes the following steps: a step of stopping the operation of the grinding device after a command to stop the operation of the grinding device is input from the input device to the control unit; and a step of grinding the holding surface with a grinding wheel after a command to stop the operation of the grinding device is input from the input device to the control unit and before the step of stopping the operation of the grinding device is completed.

In other words, when the grinding device is shut down, self-grinding, which grinds the holding surface with the grinding wheel, is always performed. Therefore, the grinding device, program, and grinding device control method of the present invention prevent the operator from forgetting to perform self-grinding.

FIG. 1 is a perspective view schematically showing a grinding apparatus. FIG. 2 is a functional block diagram that schematically shows the functional structure of the control unit. FIG. 3 is a flowchart showing the flow of processing when shutting down the grinding device. FIG. 4 is a cross-sectional view schematically showing how the holding surface of the chuck table is ground.

Embodiments of the present invention will now be described with reference to the accompanying drawings. Figure 1 is a perspective view schematically illustrating a grinding device 2 according to this embodiment. Note that in Figure 1, some of the elements constituting the grinding device 2 are represented by functional blocks. Furthermore, the X-axis direction (front-rear direction), Y-axis direction (left-right direction), and Z-axis direction (vertical direction) used in the following description are perpendicular to one another.

As shown in FIG. 1, the grinding device 2 includes a base 4 that supports the various elements that make up the grinding device 2. A recessed storage section 4a, whose upper end opens to the top surface of the base 4, is provided at the front end of the top surface of the base 4, and this storage section 4a houses a first transport mechanism 6 used to transport plate-shaped workpieces 11. The first transport mechanism 6 is typically a robot arm with multiple joints, and is capable of not only transporting the workpieces 11 but also flipping the workpieces 11 upside down.

The workpiece 11 is, for example, a disk-shaped wafer made of a semiconductor material such as silicon. That is, the workpiece 11 has a circular front surface 11a and a circular back surface 11b opposite the front surface 11a. The front surface 11a of the workpiece 11 is divided into multiple small regions by multiple intersecting streets (planned division lines), and devices such as integrated circuits (ICs) are formed in each small region.

The grinding device 2 of this embodiment is used, for example, when grinding the back surface 11b of the workpiece 11. When grinding the back surface 11b of the workpiece 11, it is desirable to attach a protective member made of a material such as resin to the front surface 11a of the workpiece 11. By attaching a protective member to the front surface 11a of the workpiece 11, the impact applied to the front surface 11a when grinding the back surface 11b is reduced, protecting the devices and other components of the workpiece 11.

In addition, in this embodiment, a disk-shaped wafer made of a semiconductor material such as silicon is used as the workpiece 11, but the material, shape, structure, size, etc. of the workpiece 11 are not limited to this embodiment. For example, a substrate made of other semiconductors, ceramics, resin, metal, or other materials may be used as the workpiece 11. Similarly, the type, number, shape, structure, size, arrangement, etc. of the devices are not limited to the above embodiment. The workpiece 11 does not need to have any devices formed on it.

As shown in Figure 1, cassette tables 10a and 10b are provided in front of the storage unit 4a, on which cassettes 8a and 8b, each capable of storing multiple workpieces 11, are placed. Diagonally rearward of the storage unit 4a, a position adjustment mechanism 12 is provided for adjusting the position of the workpieces 11. The position adjustment mechanism 12 includes a disk-shaped position adjustment table and multiple pins arranged around the periphery of the position adjustment table.

By moving multiple pins along the radial direction of the position adjustment table, the center of the workpiece 11, which has been removed from the cassette 8a by the first transport mechanism 6 and placed on the position adjustment table, can be aligned to a predetermined position in the X-axis and Y-axis directions. The workpiece 11 is placed on the position adjustment table so that its surface to be ground (in this embodiment, the back surface 11b) is exposed upward.

A second transport mechanism 14 is provided to the side of the position adjustment mechanism 12, which holds the workpiece 11 and transports it rearward. The second transport mechanism 14 includes, for example, an arm and a holding pad connected to the tip of the arm that can hold the top surface (surface to be ground) of the workpiece 11 by suction; by rotating the holding pad with the arm, the workpiece 11, whose position has been adjusted by the position adjustment mechanism 12, is transported rearward.

A turntable 16 is provided behind the second transport mechanism 14. The turntable 16 is connected to a motor (not shown) or the like, and is rotated by the power of this motor or the like around a rotation axis that is generally parallel to the Z-axis direction. Three sets of cylindrical (disk-shaped) table bases 18 are provided on the upper surface of the turntable 16, spaced at approximately equal angular intervals along the circumferential direction of the turntable 16. However, the number of table bases 18 is not limited to this.

Each table base 18 is connected to a motor (not shown) or the like, and is rotated by the power of this motor or the like around a rotation axis that is roughly parallel to the Z-axis direction or a rotation axis that is slightly tilted relative to the Z-axis direction. Each table base 18 is supported on the turntable 16 via an angle adjustment mechanism (not shown), and the angle of the rotation axis of each table base 18 is adjusted by this angle adjustment mechanism.

A disk-shaped chuck table 20 used to hold the workpiece 11 is fixed to the upper end of each table base 18 with bolts or the like. Each chuck table 20 includes a disk-shaped frame 20a (see Figure 4) made of a material such as ceramics. The upper part of the frame 20a has a recess whose upper end opens into a circular shape on the upper surface of the frame 20a. A porous disk-shaped holding plate 20b (see Figure 4) made of a material such as ceramics is fixed to this recess.

The upper surface of the holding plate 20b is configured, for example, in a shape corresponding to the side of a cone, and functions as a holding surface for holding the workpiece 11. The difference in height (height difference) between the center of the upper surface of the holding plate 20b, which corresponds to the apex of the cone, and the outer periphery of the upper surface of the holding plate 20b is approximately 10 μm to 30 μm.

The underside of the holding plate 20b is connected to a suction source (not shown) such as an ejector via a flow path provided inside the frame 20a or a valve (not shown) located outside the frame 20a. Therefore, when the valve is opened and negative pressure from the suction source is applied while the workpiece 11 or the like is in contact with the upper surface of the holding plate 20b, the workpiece 11 is sucked by the chuck table 20. In other words, the workpiece 11 is held by the holding surface of the chuck table 20.

With the chuck table 20 fixed to the table base 18, the turntable 16 rotates, for example, in the direction of the arrow in Figure 1 and in the direction opposite to the arrow. As the turntable 16 rotates, the table base 18 and chuck table 20 move circumferentially around the turntable 16.

The turntable 16 moves the table base 18 and chuck table 20, for example, through a load-in/load-out area adjacent to the second transport mechanism 14, a rough grinding area behind the load-in/load-out area, a finish grinding area to the side of the rough grinding area, and then the load-in/load-out area. The second transport mechanism 14 transports the workpiece 11 held by the holding pad from the position adjustment table of the position adjustment mechanism 12 to the chuck table 20 located in the load-in/load-out area.

As shown in FIG. 1, columnar support structures 30 are provided behind the rough grinding area and the finish grinding area (i.e., behind the turntable 16), respectively. A Z-axis movement mechanism 32 is provided on the front side of each support structure 30. Each Z-axis movement mechanism 32 has a pair of guide rails 34 that are generally parallel to the Z-axis direction, and a movement plate 36 is slidably attached to the guide rails 34.

A nut (not shown) that forms a ball screw is provided on the rear side (back side) of each moving plate 36, and a screw shaft 38 that is generally parallel to the guide rail 34 is rotatably connected to this nut. A motor 40 or the like is connected to one end of the screw shaft 38. By rotating the screw shaft 38 using the motor 40 or the like, the moving plate 36 moves along the guide rail 34 (in the Z-axis direction).

A fixture 42 is provided on the front (surface) of each moving plate 36. Each fixture 42 supports a grinding unit 44 capable of grinding the workpiece 11. Each grinding unit 44 has a spindle housing 46 fixed to the fixture 42. Each spindle housing 46 houses a spindle 48, whose rotation axis is parallel to the Z-axis direction or slightly tilted relative to the Z-axis direction, so that it can rotate around its axis.

The lower end of each spindle 48 is exposed from the lower end surface of the spindle housing 46, and a disk-shaped mount 50 is fixed to this lower end. For example, the outer edge of each mount 50 is provided with multiple holes (not shown) that penetrate the mount 50 in the thickness direction, and a bolt 52 or the like is inserted into each hole.

A grinding wheel 54 for rough grinding is attached with bolts 52 to the underside of the mount 50 of the grinding unit 44 on the rough grinding area side. In other words, the grinding wheel 54 for rough grinding is attached to the spindle 48 on the rough grinding area side. The spindle housing 46 of the grinding unit 44 on the rough grinding area side also houses a motor (not shown) and other components connected to the upper end of the spindle 48. The power of this motor rotates the grinding wheel 54 for rough grinding together with the spindle 48.

On the other hand, a grinding wheel 54 for finish grinding is attached with bolts 52 to the underside of the mount 50 of the grinding unit 44 on the finish grinding area side. In other words, the grinding wheel 54 for finish grinding is attached to the spindle 48 on the finish grinding area side. Furthermore, the spindle housing 46 of the grinding unit 44 on the finish grinding area side houses a motor (not shown) and other components connected to the upper end of the spindle 48. The power of this motor rotates the grinding wheel 54 for finish grinding together with the spindle 48.

Each grinding wheel 54 includes an annular wheel base 54a (see Figure 4) made of a metal such as stainless steel or aluminum. A plurality of grinding stones 54b (see Figure 4), each consisting of abrasive grains such as diamond dispersed in a binder such as vitrified or resinoid, are fixed to the underside of the wheel base 54a along the circumferential direction of the wheel base 54a.

The average particle size of the abrasive grains contained in the grinding stone 54b of the grinding wheel 54 for finish grinding is smaller than the average particle size of the abrasive grains contained in the grinding stone 54b of the grinding wheel 54 for rough grinding. This allows for the creation of a grinding wheel 54 suitable for rough grinding and a grinding wheel 54 suitable for finish grinding. The specific size of the abrasive grains is appropriately set depending on the quality, etc., required for the workpiece 11 after grinding.

A nozzle 56 is located next to the grinding wheel 54, which can supply a liquid (grinding fluid) 21 (see Figure 4) such as pure water to the area where the workpiece 11 and grinding stone 54b come into contact. Instead of or in addition to this nozzle 56, a liquid supply port used to supply liquid may be provided on the grinding wheel 54, etc.

The workpiece 11 held on the chuck table 20 in the rough grinding area has its upper surface ground by the grinding unit 44 on the rough grinding area side described above. Furthermore, the workpiece 11 held on the chuck table 20 in the finish grinding area has its upper surface ground by the grinding unit 44 on the finish grinding area side described above.

In other words, the chuck table 20 holding the workpiece 11 moves through the loading/unloading area, the rough grinding area, and the finish grinding area in that order, allowing the workpiece 11 to be continuously rough-ground and then finish-ground. Once the finish grinding of the workpiece 11 is complete, the chuck table 20 in the finish grinding area is again positioned in the loading/unloading area.

A third transport mechanism 58 is provided in front of the loading/unloading area and to the side of the second transport mechanism 14 to hold and transport the ground workpiece 11 forward. The third transport mechanism 58 includes a holding pad that holds the top side of the workpiece 11 by suction, and an arm connected to this holding pad. The arm rotates the holding pad to transport the ground workpiece 11 forward from the chuck table 20 in the loading/unloading area.

A cleaning unit 60 is provided to the side of the third transport mechanism 58 to clean the workpiece 11 transported by the third transport mechanism 58. The cleaning unit 60 includes, for example, a spinner table that rotates while holding the underside of the workpiece 11, and a cleaning nozzle that sprays cleaning fluid onto the upper surface of the workpiece 11 held by the spinner table.

The cleaning fluid used in the cleaning unit 60 is typically a mixed fluid (two-fluid) of water and air. Of course, water that is not mixed with air may also be used as the cleaning fluid. The workpiece 11 cleaned in the cleaning unit 60 is transported by the first transport mechanism 6 and stored, for example, in a cassette 8b.

A control unit 62 is connected to each element of the grinding device 2. This control unit 62 is configured, for example, by a computer including a processing device 62a and a storage device 62b, and controls the operation of each element of the grinding device 2 described above, including the chuck table 20, Z-axis movement mechanism 32, and grinding unit 44, so that the workpiece 11 is properly ground.

The processing device 62a is typically a CPU (Central Processing Unit) and performs the various processes required to control the above-mentioned elements. The storage device 62b includes, for example, a main storage device such as a DRAM (Dynamic Random Access Memory) and an auxiliary storage device such as a hard disk drive or flash memory. The functions of this control unit 62 are realized, for example, by the processing device 62a operating in accordance with software such as programs stored in the storage device 62b.

An input device 64 is connected to the control unit 62. The input device 64 is, for example, a touch panel, and is used to input instructions from the operator to the control unit 62. This touch panel also serves as a display device that displays information output from the control unit 62. Note that a keyboard, mouse, etc. may also be used as the input device 64.

When the grinding device 2 configured in this manner shuts down, it performs a self-grind, grinding the holding surface of the chuck table 20 with the grinding wheel 54. For example, a program for causing the control unit 62 to execute the necessary procedures is recorded in part of the storage device 62b, which is also a non-transitory recording medium that can be read by a computer, and the control unit 62 controls the shutdown in accordance with this program.

Figure 2 is a functional block diagram that schematically shows the functional structure of the control unit 62 implemented by the program of this embodiment. For ease of explanation, Figure 2 also shows an input device 64 connected to the control unit 62. As shown in Figure 2, the control unit 62 includes an input determination unit 66 that determines input from the input device 64.

For example, when an operator inputs a shutdown command (a command to stop operation of the grinding device 2) from the input device 64, the input determination unit 66 notifies the shutdown control unit 68 of the start of the shutdown procedure. The shutdown control unit 68 executes the shutdown procedure in accordance with the notification from the input determination unit 66.

For example, if the operating mode at shutdown is set to "self-grind at shutdown," which performs self-grinding, the shutdown control unit 68 notifies the self-grind control unit 70 of the start of the self-grinding procedure when starting the shutdown procedure. The self-grind control unit 70 executes the self-grinding procedure in accordance with the notification from the shutdown control unit 68.

The control unit 62 further includes an operation mode setting unit 72 that sets the operation mode at shutdown. For example, when an operation mode selected by the operator is input from the input device 64 to the input determination unit 66, the input determination unit 66 notifies the operation mode input from the input device 64 to the operation mode setting unit 72, and the operation mode setting unit 72 sets the operation mode notified by the input determination unit 66 as the operation mode at shutdown. In addition to the above-mentioned "self-grind at shutdown," operation modes at shutdown include "normal shutdown," which does not perform self-grind at shutdown.

The shutdown control unit 68 includes, for example, a power control unit 68a that controls the supply of power, and a storage control unit 68b that controls the storage of information. When the input determination unit 66 notifies the shutdown control unit 68 of the start of the shutdown procedure, the storage control unit 68b executes a procedure to store information that needs to be saved during shutdown in the storage device 62b. For example, once the procedure to store necessary information in the storage device 62b and other procedures required for shutdown are completed, the power control unit 68a executes a procedure to cut off the supply of power to each element.

The self-grinding control unit 70 includes, for example, a wheel change control unit 70a that controls the replacement of the grinding wheel 54, and an angle adjustment unit 70b that adjusts the angle of the rotation axis of the chuck table 20 (the rotation axis of the table base 18). When starting the self-grinding procedure, the wheel change control unit 70a executes, as necessary, the procedure for replacing the grinding wheel 54 suitable for grinding the workpiece 11 with a grinding wheel 54 suitable for self-grinding (grinding wheel 54 replacement procedure). Specifically, for example, the wheel change control unit 70a displays on a display device information necessary to notify the operator that the grinding wheel 54 needs to be replaced.

When starting the self-grinding procedure, the angle adjustment unit 70b executes a procedure to adjust the angle of the rotation axis of the chuck table 20 to a predetermined angle suitable for self-grinding. Specifically, for example, the angle adjustment unit 70b adjusts the angle of the rotation axis of the table base 18 using the angle adjustment mechanism described above. Note that the angle adjustment unit 70b may execute a procedure to adjust the angle of the axis of the spindle 48 instead of or in addition to the angle of the rotation axis of the chuck table 20.

Figure 3 is a flowchart showing the processing flow when shutting down the grinding device 2. First, when the input device 64 inputs a shutdown command to the control unit 62 (step ST11), the input determination unit 66 of the control unit 62 notifies the shutdown control unit 68 of the start of shutdown.

Upon receiving notification from the input determination unit 66 that the shutdown procedure has begun, the shutdown control unit 68 begins the shutdown procedure (step ST12). Specifically, for example, the storage control unit 68b begins a procedure for storing information that needs to be saved during shutdown in the storage device 62b. Note that at this stage, the power control unit 68a does not begin a procedure for cutting off the supply of power to each element.

Furthermore, upon receiving notification from the input determination unit 66 that the shutdown procedure has begun, the shutdown control unit 68 determines whether the operation mode set by the operation mode setting unit 72 is "shutdown self-grind," which performs self-grinding upon shutdown (step ST13). Note that while Figure 3 shows a flow in which the operation mode is determined after the shutdown procedure has begun, the shutdown procedure may also be initiated simultaneously with or after the operation mode is determined.

If "Self-grind at end" is set as the operating mode (YES in step ST13), the shutdown control unit 68 notifies the self-grind control unit 70 of the start of the self-grind procedure. Upon receiving notification of the start of the self-grind procedure from the shutdown control unit 68, the self-grind control unit 70 starts the self-grind procedure, for example, grinding the holding surface of the chuck table 20 with the grinding wheel 54 for finish grinding.

Specifically, for example, the angle adjustment unit 70b initiates a procedure to adjust the angle of the rotation axis of each chuck table 20 to a predetermined angle suitable for self-grinding (step ST14). That is, when each chuck table 20 is positioned in the finish grinding area, the angle adjustment unit 70b adjusts the angle between the rotation axis of that chuck table 20 and the axis of the spindle 48 to which the finish grinding grinding wheel 54 is attached to a predetermined angle suitable for self-grinding.

This adjustment is necessary because the load applied when rotating the chuck table 20 and grinding wheel 54 generally differs between grinding the workpiece 11 and grinding the holding surface of the chuck table 20. However, if there is no substantial difference in the magnitude of the load during rotation, this angle adjustment may be omitted.

Once the angle between the rotation axis of each chuck table 20 and the axis of the spindle 48 has been adjusted, the self-grinding control unit 70 begins the procedure of grinding the holding surface of the chuck table 20 with the grinding wheel 54 (step ST15). Figure 4 is a cross-sectional view that schematically shows how the holding surface of the chuck table 20 is ground. Specifically, the self-grinding control unit 70 first rotates each chuck table 20 around a rotation axis that intersects with the holding surface, and also rotates the spindle 48, to which the grinding wheel 54 for finish grinding is attached, around its axis.

Next, while the chuck table 20 and spindle 48 are rotating, the self-grind control unit 70 uses the Z-axis movement mechanism 32 to lower the grinding wheel 54 for finish grinding while supplying liquid 21 from the nozzle 56. In other words, the self-grind control unit 70 uses the Z-axis movement mechanism 32 to move the chuck table 20 in the finish grinding area and the grinding unit 44 for finish grinding relatively along the Z-axis direction, which intersects with the holding surface of the chuck table 20.

As a result, the grinding stone 54b of the finish grinding grinding wheel 54 comes into contact with the holding surface of the chuck table 20 in the finish grinding area, grinding the holding surface of the chuck table 20. The amount of grinding of the holding surface (grinding thickness) is set arbitrarily, for example, in the range of 10 μm to 50 μm. However, the amount of grinding of the holding surface is not limited to this range.

When grinding of the holding surface of the chuck table 20 in the finish grinding area is complete, the self-grinding control unit 70 rotates the turntable 16 to move another chuck table 20 to the finish grinding area, and grinds the holding surface of this other chuck table 20 in the same way. Rotation of the turntable 16 and grinding of the holding surfaces of the chuck tables 20 are alternated, and when the holding surfaces of all chuck tables 20 have been ground, the self-grinding procedure is complete.

In the self-grinding procedure performed during this shutdown, it is desirable that the wheel change control unit 70a not execute the procedure for changing the grinding wheel 54. By not executing the procedure for changing the grinding wheel 54, which requires operator work, it is possible to more reliably prevent the operator from forgetting to perform self-grinding. However, in this case, the grinding wheel 54 must be configured to be able to grind both the workpiece 11 and the chuck table 20.

Of course, in the self-grinding procedure performed during shutdown, the wheel change control unit 70a may also execute the procedure for replacing the grinding wheel 54. Furthermore, in general self-grinding procedures other than the self-grinding performed during shutdown, the wheel change control unit 70a may also execute the procedure for replacing the grinding wheel 54.

When all procedures required for shutdown, including the self-grinding procedure, have been completed, the power control unit 68a of the shutdown control unit 68 initiates a procedure to cut off the supply of power to each element to complete the shutdown procedure (step ST16). When the supply of power to each element has been cut off, all procedures to stop the operation of the grinding device 2 are completed, and the grinding device 2 enters a shut-down state.

As described above, according to the grinding device 2, program, and grinding device control method of this embodiment, when a predetermined operating mode is set, the control unit 62 executes the following steps: a procedure for stopping the operation of the grinding device 2 after a command to stop the operation of the grinding device 2 is input from the input device 64 to the control unit 62; and a procedure for grinding the holding surface with the grinding wheel 54 after a command to stop the operation of the grinding device 2 is input from the input device 64 to the control unit 62 before the procedure for stopping the operation of the grinding device 2 is completed.

In other words, when the grinding device 2 is shut down to stop operation, self-grinding, which grinds the holding surface with the grinding wheel 54, is always performed. Therefore, the grinding device 2, program, and grinding device control method of this embodiment prevent the operator from forgetting to perform self-grinding. Furthermore, the grinding device 2, program, and grinding device control method of this embodiment perform self-grinding during shutdown, which does not contribute to grinding the workpiece 11, so there is no decrease in productivity due to self-grinding.

The present invention is not limited to the above-described embodiment and can be implemented with various modifications. For example, in the above-described embodiment, a self-grinding procedure is performed in which the holding surface of the chuck table 20 is ground using a grinding wheel 54 for finish grinding, but a self-grinding procedure in which the holding surface of the chuck table 20 is ground using a grinding wheel 54 for rough grinding may also be performed.

In addition, in the above-described embodiment, the program for executing the grinding device control method is recorded in the storage device 62b within the control unit 62, but this program may also be recorded on any non-transitory recording medium that can be read by a computer, etc. For example, this program may be recorded on an optical disc such as a CD (Compact Disc), which can be distributed at low cost.

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

DESCRIPTION OF SYMBOLS 2: Grinding device 4: Base 4a: Storage section 6: First transport mechanism 8a: Cassette 8b: Cassette 10a: Cassette table 10b: Cassette table 12: Position adjustment mechanism 14: Second transport mechanism 16: Turntable 18: Table base 20: Chuck table 20a: Frame 20b: Holding plate 30: Support structure 32: Z-axis movement mechanism 34: Guide rail 36: Moving plate 38: Screw shaft 40: Motor 42: Fixture 44: Grinding unit 46: Spindle housing 48: Spindle 50: Mount 52: Bolt 54: Grinding wheel 54a: Wheel base 54b: Grinding stone 56: Nozzle 58: Third transport mechanism 60 : Cleaning unit 62 : Control unit 62a : Processing device 62b : Storage device 64 : Input device 66 : Input determination unit 68 : Shutdown control unit 68a : Power control unit 68b : Storage control unit 70 : Self-grinding control unit 70a : Wheel exchange control unit 70b : Angle adjustment unit 72 : Operation mode setting unit 11 : Workpiece 11a : Front surface 11b : Back surface 21 : Liquid (grinding fluid)

Claims (13)

A grinding device comprising:
a chuck table having a holding surface for holding a workpiece and rotatable about a rotation axis intersecting the holding surface;
a grinding unit having a spindle that can rotate around an axis with a grinding wheel attached to the tip thereof;
a movement mechanism that moves the chuck table and the grinding unit relatively in a direction intersecting the holding surface;
a control unit having a processing device and a storage device, and controlling the chuck table, the grinding unit, and the moving mechanism in accordance with a program stored in the storage device;
an input device for inputting commands to the control unit;
The program
a step of stopping the operation of the grinding device after a command to stop the operation of the grinding device is input from the input device to the control unit so that the grinding device is shut down ;
a step of grinding the holding surface with the grinding wheel by moving the grinding unit and the chuck table relative to each other by the moving mechanism while the chuck table and the spindle are rotating, after a command to stop the operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit, and before the step of stopping the operation of the grinding device is completed. The program
2. The grinding apparatus according to claim 1, wherein after a command to stop operation of the grinding apparatus so as to shut down the grinding apparatus is input from the input device to the control unit, the control unit executes a procedure of adjusting the angle formed between the rotation axis of the chuck table and the axis of the spindle before a procedure of grinding the holding surface with the grinding wheel is started. The program
3. The grinding device according to claim 1, wherein after a command to stop operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit, the control unit executes a procedure for grinding the holding surface with the grinding wheel without executing a procedure for replacing the grinding wheel attached to the spindle. The program
4. A grinding device according to claim 1, wherein the control unit executes a procedure for stopping the operation of the grinding device and a procedure for grinding the holding surface with the grinding wheel so that the procedure for grinding the holding surface with the grinding wheel is completed before the procedure for stopping the operation of the grinding device is completed. a chuck table having a holding surface for holding a workpiece and rotatable about a rotation axis intersecting the holding surface;
a grinding unit having a spindle that can rotate around an axis with a grinding wheel attached to the tip thereof;
a movement mechanism that moves the chuck table and the grinding unit relatively in a direction intersecting the holding surface;
a control unit having a processing device and a storage device, and controlling the chuck table, the grinding unit, and the moving mechanism in accordance with a program stored in the storage device;
an input device for inputting commands to the control unit; and a program used to control a grinding machine comprising the program,
a step of stopping the operation of the grinding device after a command to stop the operation of the grinding device is input from the input device to the control unit so that the grinding device is shut down ;
a program that causes the control unit to execute a procedure in which, after a command to stop operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit, and before the procedure for stopping the operation of the grinding device is completed, the grinding unit and the chuck table are moved relative to each other by the moving mechanism while the chuck table and the spindle are rotating, and the holding surface is ground by the grinding wheel. 6. The program according to claim 5 , which causes the control unit to execute a procedure for adjusting the angle between the rotation axis of the chuck table and the axis of the spindle before starting a procedure for grinding the holding surface with the grinding wheel, after a command to stop operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit. 7. The program according to claim 5 or 6, which causes the control unit to execute a procedure for grinding the holding surface with the grinding wheel without causing the control unit to execute a procedure for replacing the grinding wheel attached to the spindle after a command to stop operation of the grinding device so that the grinding device is shut down is input from the input device to the control unit. The program described in any one of claims 5 to 7 causes the control unit to execute a procedure for stopping the operation of the grinding device and a procedure for grinding the holding surface with the grinding wheel, so that the procedure for grinding the holding surface with the grinding wheel is completed before the procedure for stopping the operation of the grinding device is completed. A non-transitory recording medium on which the program described in any one of claims 5 to 8 is stored. a chuck table having a holding surface for holding a workpiece and rotatable about a rotation axis intersecting the holding surface;
a grinding unit having a spindle that can rotate around an axis with a grinding wheel attached to the tip thereof;
a movement mechanism that moves the chuck table and the grinding unit relatively in a direction intersecting the holding surface;
a control unit having a processing device and a storage device, and controlling the chuck table, the grinding unit, and the moving mechanism in accordance with a program stored in the storage device;
an input device for inputting a command to the control unit,
the input device inputting a command to the control unit to stop operation of the grinding device so that the grinding device is shut down;
a step of stopping the operation of the grinding device after a command to stop the operation of the grinding device is input from the input device to the control unit so that the grinding device is shut down;
a step of grinding the holding surface with the grinding wheel by moving the grinding unit and the chuck table relative to each other using the moving mechanism while the chuck table and the spindle are rotating, after a command to stop operation of the grinding device is input from the input device to the control unit so that the grinding device is shut down, and before the step of stopping the operation of the grinding device is completed. 11. The method for controlling a grinding apparatus according to claim 10, further comprising the step of adjusting an angle formed between the rotation axis of the chuck table and the axis of the spindle before starting the step of grinding the holding surface with the grinding wheel, after a command to stop operation of the grinding apparatus is input from the input device to the control unit so that the grinding apparatus is shut down. 12. A method for controlling a grinding apparatus according to claim 10 or 11, wherein after a command to stop operation of the grinding apparatus so that the grinding apparatus is shut down is input from the input device to the control unit, a step of grinding the holding surface with the grinding wheel is performed without performing a step of replacing the grinding wheel attached to the spindle. A method for controlling a grinding device according to any one of claims 10 to 12, wherein the step of grinding the holding surface with the grinding wheel is terminated before the step of stopping the operation of the grinding device is completed.