JP2000288928A - Grinder control method and grinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinder control method capable of accurately controlling the pressing force of a main spindle even within the range of a low pressing force, and also controlling the position and the speed of the main spindle accurately, and a grinder. SOLUTION: In a grinder provided with a man body, a main spindle A1 having a chuck A11 provided in its tip to hold a workpiece, a polishing table 31 placed oppositely to the main spindle to polish the workpierce, and a main spindle moving and pressuring means for moving and pressurizing the main spindle, with respect to the main body, in the axial direction of the main spindle by a servo motor 42 capable of controlling torque, during the movement of the main spindle toward the polishing table, the movement of the main spindle is carried out by speed control and position control before the position of the main spindle reaches a specified position near the polishing table, and by the toque control of the servo motor after the specified position, and during the movement of the main spindle away from the polishing table, the movement of the main spindle is carried out by the speed control and the position control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing machine for performing high-precision or ultra-high-precision planar polishing on a workpiece such as a semiconductor wafer. TECHNICAL FIELD The present invention relates to a polishing disk control method and a polishing disk which can be controlled and can accurately control the position, speed and acceleration of a spindle.

[0002]

2. Description of the Related Art As a polishing machine for performing ultra-high-precision planar polishing on a workpiece such as a semiconductor wafer, a polishing machine having a plurality of spindles as described in Japanese Patent Application Laid-Open No. 9-277165 is known. Boards are known. Such a polishing machine holds a workpiece such as a semiconductor wafer on a chuck provided at a lower end of a plurality of spindles, and performs polishing by moving between a plurality of polishing tables. The rotary column supporting a plurality of spindles can be indexed and rotated and stopped every 90 degrees, and the positions of the spindles are sequentially set in a pre-polishing temporary table, a first polishing table, a second polishing table, and a post-polishing temporary table. Can be moved to the position. In Japanese Patent Application Laid-Open No. 9-277165, a workpiece is polished by four main spindles divided into two groups.

In a conventional polishing machine, the rotation and vertical movement of the spindle and the rotation of the polishing table are performed by a driving mechanism as shown in FIG. That is, the polishing table 31 and the table shaft 311 are driven to rotate by the table rotation motor 312, and the main shaft A1 is driven to rotate by the main shaft rotation motor 41. The spindle A1 is moved up and down by a pneumatic cylinder 45, and the pneumatic cylinder 45 controls the pressing force of the workpiece on the polishing table 31. Here, the workpiece is held on the lower surface of the chuck A11 at the lower end of the spindle A1 by bonding or the like.

[0004]

In the conventional polishing machine, the main shaft is moved up and down by the pneumatic cylinder as described above, and the control of the pressing force of the workpiece to the polishing table is also performed by the pneumatic cylinder. Was. As the processing accuracy of semiconductor wafers is required to be higher, it is necessary to control the pressure applied to the polishing table of the workpiece to a small value even in processing with a polishing machine. Further, it is necessary to precisely control the pressing force in the step pressing process in which the pressing force is gradually increased or decreased with time and in the inclined pressing process in which the pressing force is continuously increased or decreased with time.

In the control using a pneumatic cylinder, accurate control at a low pressure is impossible or extremely difficult due to frictional resistance between the cylinder sliding surface and the seal member and hysteresis characteristics during reciprocation. There is a problem that it is extremely difficult to precisely control the pressing force in the pressure processing and the inclined pressure processing. Further, when the chuck is replaced, the self-weight of the spindle changes, so that it is necessary to change the setting of the pneumatic pressure of the pneumatic cylinder, which causes a problem that the operation becomes complicated.

[0006] In the polishing machine, the speed such as the lowering position of the main shaft when the workpiece comes in contact with the polishing table, the lowering speed, the rising speed of the main shaft when separating the workpiece from the polishing table, the rapid feed speed of the main shaft, and the like. It is necessary to control to a desired value or to control the acceleration at the time of speed change to a desired value. Such control of the position, speed, and acceleration has a problem that it is difficult to perform accurate control with a pneumatic cylinder.

Further, in the polishing machine, when holding an unprocessed workpiece on the chuck at the lower end of the main spindle or peeling the processed workpiece from the chuck, the main spindle is moved to an accurate lowering position to stop positioning. There is a need to do. There is a problem that it is difficult to control the position accurately with the pneumatic cylinder.

Accordingly, the present invention provides a control of a polishing machine capable of accurately controlling the pressing force of the main shaft of the polishing machine even in a low pressure range, and further capable of accurately controlling the position, speed and acceleration of the main shaft. It is an object to provide a method and a polishing machine.

[0009]

In order to achieve the above object, a method for controlling a polishing machine according to the present invention comprises a main body, a main spindle provided with a chuck for holding a workpiece at a tip end thereof, and a main body opposed to the main spindle. A polishing table comprising: a polishing table for polishing a workpiece; and a spindle moving / pressing means for moving and pressing the spindle in the axial direction of the spindle with respect to the main body by a servomotor capable of controlling torque. When the spindle moves in the direction of the polishing table, the speed control and the position control are performed until the position of the spindle reaches a predetermined position close to the polishing table. The main spindle is moved by control, and when the main spindle is moved in a direction away from the polishing table, the main spindle is moved by speed control and position control. It is. Here, the predetermined position close to the polishing table corresponds to the lower end position of the spindle at the polishing table position in the embodiment of the present invention.

[0010] In the above method of controlling a polishing machine,
From the drive torque of the servo motor, which is balanced with the weight of the moving body in the direction of the spindle axis including the main shaft, a self-weight torque corresponding to the self-weight of the moving body is obtained, and the relationship between the self-weight torque and a set value of the pressing force is used. It is preferable that a command torque of the servo motor corresponding to the pressing force is obtained, and the control of the pressing force is performed by controlling the torque of the servo motor.

[0011] In the above-mentioned method for controlling a polishing machine,
It is preferable that the polishing machine has a plurality of the spindles, and it is preferable that the pressure can be controlled independently for each of the spindles.

In addition, the polishing machine of the present invention has a main body, a main spindle provided with a chuck for holding a workpiece at a tip end, a polishing table opposed to the main spindle for polishing the workpiece, and a torque controllable. A spindle moving / pressurizing means for moving and pressing the spindle in the axial direction of the spindle with respect to the main body by a servomotor; and when the spindle is moved in the direction of the polishing table, the position of the spindle is close to the polishing table. The spindle is moved by speed control and position control until the predetermined position is reached, and by the torque control of the servomotor after the predetermined position, the speed is controlled when the spindle moves in a direction away from the polishing table. Control means for moving the spindle by control and position control. Here, the predetermined position close to the polishing table corresponds to the lower end position of the spindle at the polishing table position in the embodiment of the present invention.

Further, in the above-mentioned polishing machine, it is preferable that the main spindle moving and pressing means includes a ball screw.

Further, in the above-mentioned polishing machine, the control means calculates a self-weight torque corresponding to the self-weight of the moving body from a driving torque of the servomotor which is balanced with the self-weight of the moving body in the main shaft axis direction including the main shaft. Preferably, a command torque of the servo motor corresponding to the pressing force is obtained from a relationship between the own weight torque and a set value of the pressing force, and the pressing force is controlled by torque control of the servo motor. .

In the above-mentioned polishing machine, it is preferable that the polishing machine has a plurality of the spindles, and the control means is capable of controlling the pressure independently for each of the plurality of spindles.

[0016]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a polishing machine 1 to which the present invention is applied. FIG. 2 is a partial front view showing a part of the spindle head A of the polishing machine 1 and the polishing table 31.
The polishing machine 1 specifically performs ultra-high-precision planar polishing on a processed surface of a semiconductor wafer by chemical mechanical polishing (hereinafter, referred to as CMP).
In CMP, a processing surface of a workpiece is polished by a polishing table formed of a nonwoven cloth surface plate while supplying a slurry in which polishing abrasive grains are mixed in a processing liquid such as an acid or an alkali that causes a chemical reaction with the workpiece. Is what you do.

On the upper surface of the main body 2 of the polishing machine 1, three polishing tables 31, 32, 33 are provided. An indexing column 4 is provided at the center of the upper surface of the main body 2 so as to be rotatable around a vertical axis. Four vertical side surfaces are formed on the outer periphery of the indexing column 4 every 90 degrees, and these vertical side surfaces are respectively provided with the spindle heads A, B,
C and D are provided. The main spindle head A is provided with two main spindles A1 and A2 so as to be movable in the axial direction of the main spindles A1 and A2. C1, C2, spindle D
1 and D2 are provided movably in the axial direction.

The indexing column 4 is driven to rotate about a vertical axis, and can be positioned and indexed every 90 degrees. In FIG. 1A, the spindle head D is located on the supply / discharge table 5, the spindle head A is located on the polishing table 31, the spindle head B is located on the polishing table 32, and the spindle head C is located on the polishing table. 33.

On the upper surface of the main body 2, a supply / discharge table 5 is provided so as to be movable on a horizontal plane. As shown in FIG. 1B, the supply / discharge table 5 includes a positioning tank 51,
Reference numeral 52 is provided at a position capable of opposing two spindles of each spindle head. Further, the supply / discharge table 5 is provided with peeling tanks 53 and 54 at positions capable of opposing two spindles of the respective spindle heads.

A supply base 6 protrudes from the main body 2, and a supply robot 65 and supply cassettes 61 and 62 are provided on the supply base 6. The unprocessed workpiece is taken out of the supply cassettes 61 and 62 by the supply robot 65, and is placed and positioned on the positioning tanks 51 and 52 moved rightward in FIG. 1A.

The positioning tanks 51 and 52 on which the workpieces are mounted move to the left in FIG. 1A together with the supply / discharge table 5, and are positioned just below the spindle head D as shown in FIG. Is done. Thereafter, the spindles D1 and D2 are lowered, and the workpiece is held on a chuck at the lower end of the spindles D1 and D2 by bonding or the like. The holding of the workpiece to the chuck includes, for example, one using water surface tension, one using wax, and one using vacuum suction. FIG. 2 shows the chuck A11 on the main shaft A1. Similarly, chucks are provided at the lower ends of the other spindles, respectively.

When the workpiece is held on the chucks at the lower ends of the spindles D1 and D2 of the spindle head D, the indexing column 4 is rotated counterclockwise by 90 degrees, and the spindle head D is indexed to a position immediately above the polishing table 31. Then, while the slurry is being supplied, the polishing table 31 is driven to rotate, and the spindle D
1, D2 is lowered to polish the workpiece held by the chuck. At this time, in the other polishing tables 32 and 33, polishing is performed by the spindle heads A and B at the same time.

When the machining of the spindle head D on the polishing table 31 is completed, the spindles D1 and D2 are raised, and the indexing column 4 is driven to rotate, and is indexed to a position immediately above the polishing table 32 which has been further rotated by 90 degrees. Then, the polishing process is performed on the polishing table 32, and the polishing process is performed on the polishing table 33 in the same manner after the index rotation by 90 degrees. By sequentially performing the polishing using the polishing tables 31, 32, and 33 in this manner, the polishing process serving as a bottleneck can be dispersed, and the polishing can be performed with high efficiency.
Each of the polishing tables 31, 32, and 33 has, for example, rough processing, medium finishing processing, finishing processing, or
Processing conditions such as roughing, roughing, and finishing are assigned.

When the polishing by the polishing tables 31, 32 and 33 is completed, the spindle head D is again indexed to the position of the supply / discharge table 5. The supply / discharge table 5 is moved rightward in FIG.
Are positioned immediately below the spindles D1 and D2. Then, the spindles D1 and D2 are lowered, and the workpiece held by the chuck and having been processed is peeled in the peeling tanks 54 and 53.
At this time, the supply robot 65 is provided in the positioning tanks 51 and 52.
An unprocessed workpiece is placed on the workpiece. Next, the supply / discharge table 5 is moved to the left in FIG.
The unprocessed workpiece is held by the chuck at the lower end of D2, and the workpiece after processing is stored in the storage cassettes 63 and 64 from the peeling tanks 53 and 54.

The spindle head D has been described above.
The same applies to the other spindle heads A, B, and C. At the same time as the peeling of the processed workpiece and the supply of the unprocessed workpiece to one spindle head, the polishing can be performed to the other three spindle heads. Thereby, polishing can be performed with high efficiency.

FIG. 3 is a mechanism diagram showing a drive mechanism for the main shaft and the polishing table. FIG. 3 shows the main shaft A1 and the polishing table 31, but the other main shafts and the polishing table also have the same drive mechanism. The polishing table 31 is driven to rotate by driving a table shaft 311 by a table rotation motor 312, and the main shaft A1 is driven to rotate by a main shaft rotation motor 41. The main shaft A1 is moved up and down by a ball screw screw shaft 43 and a ball nut 44 driven by a main shaft moving motor. As the spindle moving motor 42, a servomotor capable of controlling the driving torque by controlling the driving current is used.

By controlling the torque of the main shaft moving motor 42, it is possible to control the pressing force of the workpiece on the polishing table 31. The vertical position of the main shaft A1 is detected by a known pulse generator or position detector. By feeding back the information on the vertical position to drive and control the spindle moving motor 42, the vertical position, speed, and acceleration of the spindle A1 can be controlled to desired values.

FIG. 4 is a block diagram showing the configuration of the control device 7 of the polishing machine 1. The control device 7 is provided with a CPU 71 as information processing means for performing various data processing, and a ROM 73 and a RAM 74 are connected to the CPU 71 via a bus 72 as main storage devices. CP
U71 operates according to the system programs and data stored in ROM 73 and the programs and data read and stored in RAM 74.

The programs read into the RAM 74 in this way include an OS (operating system) as a basic program, a supply control program 741, a machining control program 742, and other control programs. The supply control program 741 is a program for separating a processed workpiece and supplying an unprocessed workpiece to each spindle. The processing control program 742 is a program for controlling the processing operation of the polishing processing. The other control programs perform all other control processes related to the control device 7, such as displaying characters and graphics on the display unit 76.

The RAM 74 stores recipe data 74
3, a storage area for the pressurization parameter 744, and a storage area for the descending end position data 745. The recipe data 743 is data for specifying a processing procedure of the polishing processing. Recipe data is prepared for each type of processing such as roughing and finishing. The pressurization parameters 744 include the respective spindles A1, A2 to D1, D2
The data necessary for controlling the pressure to a desired value is set for each of them. Descending end position data 745
Is for setting a descending end position, a feed speed change position, a feed speed, an acceleration, and the like for each spindle.

A fixed disk device 75 as an auxiliary storage device is connected to the CPU 71 via a bus 72.
Various programs and the like to be executed by the CPU 71 are stored in the fixed disk device 75, and these programs and the like are appropriately stored in the fixed disk device 75 by the RAM 7.
4.

The CPU 71 is connected to input / output devices via a bus 72. As input / output devices, display means 76 for displaying characters and figures and input means 77 for an operator to input data are connected to the bus 72 via an interface circuit. As the display means 76, a CRT, an EL display panel, a liquid crystal display, or the like can be used.
A touch panel or the like integrated with the above can be used.

The control device 7 is provided with a supply control section 78 and a processing control section 79. The supply control unit 78 controls the supply / discharge table 5 and the supply robot 65 to supply a workpiece and peel the workpiece. The processing control unit 79 controls the indexing column 4, the spindle heads A to D, the polishing tables 31 to 33, the supply of the slurry, and the like to perform the polishing processing. Control signals to the supply control unit 78 and the processing control unit 79 are given by a supply control program 741 and a processing control program 742, respectively.

FIG. 5 is a block diagram showing details of the machining control section 79 of the control device 7. Command data designating the rotation speed of the polishing table 31 is transmitted from the bus 72 via the interface circuit, and is input to the amplifier 791. The amplifier 791 supplies driving power to a table rotation motor 312 for driving the polishing table 31 to rotate. The rotation speed of the table rotation motor 312 is detected by the detector 3
The control signal is fed back to the amplifier 791 via the controller 13 and is controlled so as to maintain the rotation speed of the table rotation motor 312 at a specified value. Polishing table 32,
A similar control circuit is provided for 33 as well.

Command data designating the rotation speed of the spindle A1 is transmitted from the bus 72 via the interface circuit and input to the amplifier 792. Amplifier 792
Is a spindle rotating motor 41 for rotating the spindle A1.
To supply the driving power. The rotation speed of the spindle rotation motor 41 is fed back to the amplifier 792 via the detector 411, and is controlled so that the rotation speed of the spindle rotation motor 41 is maintained at a specified value. Spindles A1, A2
A similar control circuit is provided for each of .about.D1 and D2.

Next, a control circuit for vertically moving the main shaft A1 will be described. The main shaft moving motor 42 is a servomotor whose drive torque can be controlled by a drive current. Bus 72
Control signals transmitted from the controller via the interface circuit 796 include torque command data for performing torque control and position command data for performing position control. The torque command data is output to an output line F, and the position command data is output. Output to line G. Further, the output of the selection circuit 795 can be selectively switched by a selection signal from the output line E.

The rotation angle data of the spindle moving motor 42 is detected by the detector 421 and input to the position control circuit 794. The position control circuit 794 calculates the current position of the spindle A1 based on the data from the detector 421, and compares it with the position command data from the output line G. Then, torque command data to the spindle moving motor 42 is calculated based on the difference between the position command data and the current position, and output from the output line H.

The selection circuit 795 selectively selects one of the torque command data from the output line F and the torque command data based on the position command data from the output line H.
93. As shown in FIG. 5, when the selection circuit 795 is set to output the signal of the output line F, the spindle moving motor 42 enters a torque control mode controlled by torque command data. When the selection circuit 795 is set to output the signal of the output line H, the spindle moving motor 42 enters the position control mode controlled by the position command data. In the position control mode, it is possible to control not only the position of the main shaft but also the speed and the accurate control of the acceleration. In the torque control mode, the pressure applied to the polishing table of the workpiece can be accurately controlled.

The driving torque of the spindle moving motor 42 is determined by the output line J from the amplifier 793 and the interface circuit 7.
96. The CPU 71 can read the drive torque of the spindle moving motor 42 via the interface circuit 796. The control circuit for the vertical movement of the main shaft and the pressing force as described above includes the main shafts A1, A2 to D1, D
2 is provided for each. Therefore, the main shafts A1, A2 to D1, and D2 can independently control the vertical movement and the pressing force.

FIG. 6 is a diagram showing the contents of the recipe data 743 and the pressurization parameter 744. FIG. 6A shows the recipe data 743. Recipe data is prepared for each type of processing such as roughing and finishing. For example, for rough machining, machining conditions are designated by machining procedure 1 to machining procedure n as shown in FIG. That is, processing procedure 1
The polishing at the pressing force, the spindle rotation speed, and the table rotation speed (the number of rotations of the polishing table) specified in the above is continued for the specified time, and then the polishing under the processing conditions specified in the processing procedure 2 is specified. And the processing procedure n
The process is repeated until it.

Here, the pressurizing mode designates a step pressurizing mode or a tilt pressurizing mode. In the step pressing mode, the pressing force is maintained at a constant value in the processing procedure, and the pressing force changes stepwise. In the inclined pressurizing mode, the pressing force is continuously changed within the processing procedure. For example, a start value and an end value of the pressing force are set, and the pressing force is linearly changed from the start value to the end value in the machining procedure.
The start value of the pressing force may be used as the end value of the pressing force in the pre-processing procedure, and only the end value of the pressing force may be set. That is, the processing procedure 4 in FIG. 6A is an inclined pressing mode, in which the pressing force is changed linearly from 250 gf / cm ² to 200 gf / cm ² in a processing time of 30 seconds.

FIG. 6B shows the contents of the pressurization parameter 744. In order to set a desired pressure on the workpiece, the following calculation is performed. The pressing force is converted into a driving torque of the main shaft moving motor to obtain a required torque T, and a driving torque corresponding to the own weight of the main shaft, the chuck and the like is set to the own weight torque W. In order to control to a desired pressure, the spindle moving motor is set to the torque control mode, and a control signal of the command torque t is sent to the spindle moving motor. The command torque t is t
= K (T−W). Here, k is a correction coefficient.

The pressurizing parameter 744 includes the main shafts A1, A2
The correction coefficient k, the own weight torque W, and the like are set and stored for each of .about.D1 and D2. Correction coefficient k
Is for correcting an error in the pressing force due to frictional resistance of a mechanical system or the like. If the correction coefficient is “1”, there is no correction. The own weight torque is calculated for each spindle A1, A2 to D1, D2.
Each time, it is automatically measured at the start of processing and is automatically set as a pressurization parameter. The measurement of the own weight torque will be described later. In order to set the pressing force to a value smaller than that due to the own weight of the main shaft, the command torque t may be set to a negative value (torque in the rising direction of the main shaft) from the above equation, and the low pressing force may be accurately set and controlled. Can be.

FIG. 7 is a diagram showing the contents of the falling edge position data 745. The descending end position data 745 includes the spindle A
The lower end position of the vertical movement, the feed speed, the changed position of the feed speed, and the like are set and stored for each of 1, A2 to D1, and D2. The table 1 lower end position is the lower end position of the spindle at the position of the polishing table 31. The table 2 lower end position, the table 3 lower end position, the positioning tank lower end position, and the peeling tank lower end position correspond to the polishing table 32,
Polishing table 33, positioning tanks 51 and 52, peeling tank 5
This is the lower end position corresponding to 3, 54. The descent / elevation rapid traverse speed is a rapid traverse speed when the spindle is lowered and when the spindle is raised.

The descending intermediate position is a position where the fast-forward speed is switched to the low-speed feed speed when the spindle is lowered. The descending low-speed feed speed is a low-speed feed speed when the main shaft is lowered. The acceleration at the time of descent deceleration is the acceleration at the time of switching from the fast feed speed to the low feed speed when the spindle is lowered. The descending end torque is a torque designated when the spindle is lowered by the torque control after the spindle reaches the descending end position until the workpiece comes into contact with the polishing table. The ascending intermediate position is a position at which the speed is switched from the low-speed feed speed to the fast-feed speed when the spindle is raised. The ascending low-speed feed speed is a low-speed feed speed when the spindle is raised.
The ascending low-speed feed start acceleration is the acceleration at which the spindle starts to ascend at a low feed speed after machining is completed. In accordance with the descending end position data 745 as described above, the movement and positioning of the spindle are controlled.

FIG. 8 is a flowchart showing the procedure of the pressing operation of the polishing process of the polishing table 1. For the spindles indexed on the polishing table, the machining control program 742
This pressurizing operation is performed, and polishing is performed. First, in step 101, the control circuit of the spindle moving motor is set to the position control mode. Next, in step 102, the spindle is lowered at the rapid traverse speed to the lowering intermediate position. Step 10
In 3, the spindle is decelerated from the lower intermediate position to the low-speed feed speed, and further lowered to the lower end position. Deceleration from the fast-forward speed to the low-speed feed speed is performed in accordance with the descent-deceleration acceleration data in the descent-end position data 745.

When the spindle reaches the lower end position, step 104
Then, the control circuit of the spindle moving motor is set to the torque control mode. Then, in step 105, a control command for designating the descending end torque to the spindle moving motor is given to the control circuit. The main shaft is further lowered by the main shaft moving motor to which the lower end torque is commanded. Step 106 is to detect and confirm that the workpiece comes into contact with the polishing table. The contact is detected by monitoring the descending speed of the main shaft due to the descending end torque and detecting a decrease in the descending speed due to the contact between the workpiece and the polishing table. The contact confirmation may be made such that the contact is made after a predetermined time has elapsed since the descent by the descent end torque is started without performing such detection.

When the contact between the workpiece and the polishing table is confirmed, the processing of the processing procedure 1 of the recipe data 743 is subsequently executed in step 107. Then, in step 108, the processing procedure 1 is continued until the set time of the processing procedure 1 has elapsed. Next, the processing of the processing procedure 2 is executed in step 109. Then, in step 110, the machining procedure 2 is continued until the set time of the machining procedure 2 elapses. In this way, the processing procedures 3, 4,... Are sequentially executed according to the recipe data 743. Then, the processing of the last processing procedure n is executed in step 111. Next, in step 112, the processing procedure n is continued until the set time of the processing procedure n has elapsed.

When the machining is completed, in step 113, the control circuit of the spindle moving motor is set to the position control mode. Next, in step 114, the main shaft is raised at a low feed speed to the raising intermediate position. When the workpiece is separated from the polishing table, the acceleration from the start of the ascent to the low-speed feed speed is controlled according to the data of the ascending low-speed feed start acceleration in the descent end position data 745. In step 115, the spindle is accelerated from the rising intermediate position to the rapid traverse speed and further raised to the rising end position.
Then, the pressurizing operation ends.

FIG. 9 is a flowchart showing a procedure for measuring the own weight of the polishing machine 1. This shows a procedure for measuring the own weight torque performed on any one of the spindles. When the self-weight measurement is started, in step 201, the control circuit of the spindle moving motor is set to the position control mode. Next, in step 202, the spindle is stopped at an arbitrary designated position (which may be the current position), and in step 203, the driving torque of the spindle moving motor is measured. The drive torque of the spindle moving motor in a state where the spindle is stopped is the own weight torque. The drive torque of the spindle moving motor is monitored by the output line J in FIG.
The data can be read through the interface circuit 796. When the procedure 203 is completed, the self-weight measurement ends.

At the start of machining, the spindles A1, A2 to D1, D2
, The self-weight measurement is automatically performed, and the measured self-weight torque is automatically set in the storage area for the pressurization parameter 744. Therefore, even when the spindle of the spindle is replaced, the total weight of the replaced chuck and the spindle is automatically measured and set in the storage area for the pressurization parameter 744. Therefore, there is no need for the operator to change the setting of the own weight parameter accompanying the chuck replacement, and there is no processing error or the like accompanying the chuck replacement.

In the above embodiment, the polishing board is a CMP polishing board. However, other than the CMP polishing board, a lapping machine, a polishing apparatus, a plane polishing machine using a polishing table made of a grindstone, or the like may be used. You may. In addition, although the description has been given of the polishing machine having four polishing heads and three polishing tables, the number of polishing heads and polishing tables may be any number and may be one. The number of spindles may be any number and may be one.

[0053]

Since the present invention is configured as described above, it has the following effects.

Since position control and torque control are performed by a servomotor without using a pneumatic cylinder, accurate control is possible even with a low pressure. In addition, precise control of the pressing force such as step pressing and tilt pressing can be performed. Further, the position, speed, and acceleration of the spindle can be accurately controlled, and the performance as a polishing machine is improved.

The self-weight torque corresponding to the self-weight of the moving body is automatically obtained, and the pressing force is obtained in consideration of the self-weight torque. Therefore, even when the chuck is replaced, the operator can change the setting by the self-weight of the spindle. It is not necessary to carry out the work, and the operation is simplified, and the processing error is eliminated.

[Brief description of the drawings]

FIG. 1 is a plan view of a polishing machine to which the present invention is applied.

FIG. 2 is a partial front view of the polishing machine.

FIG. 3 is a mechanism diagram showing a drive mechanism of a spindle and a polishing table.

FIG. 4 is a block diagram showing a configuration of a control device of the polishing machine.

FIG. 5 is a block diagram illustrating a configuration of a processing control unit of the control device.

FIG. 6 is a diagram illustrating recipe data and pressurization parameters;

FIG. 7 is a diagram illustrating descending end position data;

FIG. 8 is a flowchart illustrating a procedure of a pressing operation of the polishing machine.

FIG. 9 is a flowchart illustrating a procedure of measuring the own weight of the polishing machine.

FIG. 10 is a mechanism diagram showing a conventional spindle and polishing table drive mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Polishing machine 2 ... Main body 4 ... Indexing column 5 ... Supply / discharge table 6 ... Supply base 7 ... Control device A, B, D, C ... Spindle head 31, 32, 33 ... Polishing table 41 ... Spindle rotation motor 42 ... Spindle motor 43 ... Screw shaft 44 ... Ball nut 45 ... Pneumatic cylinder 51 ... Positioning tank 53,54 ... Separation tank 61 ... Supply cassette 63 ... Storage cassette 65 ... Supply robot 71 ... CPU 72 ... Bus 73 ... ROM 74 ... RAM 75 ... Fixed disk device 76 ... Display means 77 ... Input means 78 ... Supply control unit 79 ... Processing control unit A1, A2 to D1, D2 ... Main shaft 311 ... Table shaft 312 ... Table rotation motor A11 ... Chuck

Claims (7)

[Claims] 1. A main body (2), a main spindle provided with a chuck for holding a workpiece at a tip end, a polishing table (31-33) opposed to said main spindle for polishing a workpiece, and a torque controllable. A method for controlling a polishing machine (1) including a spindle moving / pressing means (42 to 44) for moving and pressing the spindle in the axial direction of the spindle with respect to the main body (2) by a simple servomotor (42). When the spindle is moved in the direction of the polishing table (31 to 33), the position of the spindle is changed to the position of the polishing table (31 to 31).
33) The main spindle is moved by speed control and position control until reaching a predetermined position close to 33) and by the torque control of the servomotor (42) after the predetermined position, and moves away from the polishing table of the main shaft. A method for controlling a polishing machine that moves the spindle by speed control and position control when moving in a direction. 2. The method for controlling a polishing machine according to claim 1, wherein the driving torque of the servo motor is adjusted based on the driving torque of the servo motor in the direction of the axis of the spindle including the spindle. A self-weight torque corresponding to the self-weight is obtained, and a command torque of the servomotor (42) corresponding to the pressing force is obtained from a relationship between the self-weight torque and a set value of the pressing force, and a torque control of the servomotor (42) is performed. A method of controlling a polishing machine for controlling the pressing force. 3. The method for controlling a polishing machine according to claim 1, wherein said polishing machine has a plurality of said spindles, and said polishing machine is independent of each of said plurality of spindles. A method for controlling a polishing machine, wherein the pressure can be controlled. 4. A main body (2), a main spindle provided with a chuck for holding a workpiece at a tip end thereof, and a polishing table (3) opposed to the main spindle for polishing the workpiece.
1 to 33), main shaft moving / pressing means (42 to 44) for moving and pressing the main shaft in the axial direction of the main shaft with respect to the main body (2) by a servomotor (42) capable of controlling torque; When the main spindle moves in the direction of the polishing table (31-33), the position of the main spindle is changed to the position of the polishing table (31-31).
33) The main shaft is moved by speed control and position control until reaching a predetermined position close to 33) and by the torque control of the servomotor (42) after the predetermined position, and moves away from the polishing table of the main shaft. A polishing means having control means (7) for moving the spindle by speed control and position control when moving in the direction. 5. The polishing machine according to claim 4, wherein said main shaft moving and pressing means includes a ball screw. 6. A polishing machine according to claim 4, wherein said control means (7) balances the weight of a moving body in a direction of a spindle axis including said spindle. A self-weight torque corresponding to the self-weight of the moving body is obtained from the drive torque of (42), and a command torque of the servo motor (42) corresponding to the pressurizing force is obtained from a relationship between the self-weight torque and a set value of the pressurizing force. A polishing machine for controlling the pressing force by torque control of the servo motor (42). 7. The polishing machine according to claim 4, wherein said polishing machine has a plurality of said main shafts, and said control means (7) is independently provided for each of said plurality of main shafts. A polishing machine capable of controlling the pressing force.