JPH10277920A - Lapping work holding device and lapping machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To variable set lapping pressure by automatic control. SOLUTION: This device is provided with a housing 15 which is supported by a moving body to be driven vertically, a work main shaft 19 with a work holding unit 17 in a lower end part which is supported by the housing 15 so that it can turn and move vertically in a prescribed scope, a main shaft rotation driving means 21 to rotate and drive the work main shaft 19, and a main shaft floating means 23 which floats the work main shaft 19 to a rising direction to the housing 15, In this case, the work main shaft 19 establishes lapping pressure variably by balanced relation between a tare and a floating force provided by the main shaft floating means 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lapping work holding device and a lapping machine.

[0002]

2. Description of the Related Art In a conventional lapping machine, as shown in FIGS. 3 and 4, a workpiece W and a weight 101 are placed on a lap table 100 on which abrasive grains such as diamond fine particles are sprayed. The lap pressure is applied by the weight 101, the fork-shaped guide roller member 102 holds the superimposed body of the workpiece W and the weight 101 so as to be able to rotate, and the rotation of the lap table 100 causes the superimposed body of the workpiece W and the weight 101 to rotate. Is rotated in a passive manner to finish the surface of the work W by wrapping.

[0003]

In the conventional lapping machine described above, the lap pressure must be changed by replacing the weight 101, and the lap pressure cannot be variably set by automatic control.

In the conventional lapping machine described above,
Measure the lap polishing amount and quantitatively adjust the lap polishing amount,
It is difficult to manage, and it is not possible to realize numerical control by an NC program for lapping with a lapping machine.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. The lap pressure can be variably set by automatic control, and the lap polishing amount is measured to quantitatively control the lap polishing amount. It is an object of the present invention to provide a lapping work holding device and a lapping machine which enable lapping by numerical control.

[0006]

According to a first aspect of the present invention, there is provided a lapping work holding apparatus, comprising: a housing supported by a vertically movable body driven in a vertical direction; A work spindle having a work holding portion at a lower end portion supported so as to be more rotatable and vertically movable by a predetermined range, a spindle rotation driving means for rotating the work spindle, and moving the work spindle in an ascending direction with respect to the housing. A spindle levitation means for levitation, wherein the workpiece spindle variably sets a lap pressure in accordance with an equilibrium relationship between its own weight and a levitation force given by the spindle levitation means.

In the lapping work holding device according to the present invention, the work held by the work holding portion is forcibly driven to rotate at the main spindle rotation speed by rotating the work main shaft by the main shaft rotation driving means. The lap pressure is variably set based on an equilibrium relationship between the self-weight of the main shaft and the floating force applied to the work main shaft by the main shaft floating means.

According to a second aspect of the present invention, there is provided a lapping work holding apparatus according to the first aspect, further comprising a lower limit position detecting means for detecting that the work spindle is at the lowermost position. Is what you are doing.

In the lapping work holding apparatus according to the present invention, the work held by the work holding portion of the work spindle contacts (contacts) with the lap table due to the lowering of the entire housing. Moves upward with respect to the housing, and the work spindle separates from the lower limit position. This is detected by the lower limit position detecting means, and it becomes possible to measure the coordinate position (Z-axis coordinate value) at which the work contacts the lap table. The housing is lowered by the lap polishing amount from the Z-axis coordinate position of the lower limit position detection, and the lower limit position detecting means detects that the work spindle has returned to the lower limit position, thereby quantitatively setting the lap polishing amount. , Can be controlled.

In order to achieve the above object, a lapping machine according to a third aspect of the present invention includes a lap table rotatably provided, a rotation driving means for driving the lap table to rotate, a first or a second aspect. 2. A vertical moving body that supports the lapping work holding device according to 2 and that can move in the vertical direction, and a servo device that drives the vertical moving body in a vertical direction.

In the lapping machine according to the present invention, the servo device controls the positioning of the vertical moving body and the lapping work holding device according to the above-mentioned invention attached thereto, and quantitatively sets and controls the lap polishing amount. can do.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of a lapping machine having a lapping work holding device according to the present invention.

As shown in FIG. 1, the lapping machine
A disk-shaped lap table 3 provided to be rotatable about its own center by a vertical axis 1, a table drive motor 5 for rotating and driving the lap table 3, and a Z-axis moving in the Z-axis direction by a Z-axis feed screw 7. Slider (vertical moving body) 9
And a Z with a position detector that rotationally drives the Z-axis feed screw 7
It has a shaft servomotor 11 and a lapping work holding device 13 fixedly mounted on the Z-axis slider 9.

The work holding device 13 for lapping is provided with a housing 15 fixed to the Z-axis slider 9, and a vacuum chuck type having a slight inclination function at a lower end supported by the housing 15 so as to be rotatable and vertically movable within a predetermined range. A work spindle 19 to which a work holding table 17 is attached, a spindle motor 21 for rotating the work spindle 19, and a work spindle 1
Pneumatic main shaft levitation means 23 for floating the housing 9 in the ascending direction with respect to the housing 15 is provided.

FIG. 2 shows the detailed structure of the lapping work holder 13.

The work spindle 19 is rotatably supported by the housing 15 by an aerostatic bearing 25. The cylinder tube 27 of the spindle floating means 23 and the coupling housing 29 are connected and fixed in order to the upper end of the housing 15, and the spindle motor 21 is mounted on the upper end of the coupling housing 29.

In the cylinder tube 27, the work spindle 1 is provided.
9 has a flange-shaped piston 31 provided at an intermediate portion in the axial direction, and an air chamber 35 to which compressed air is supplied from an air passage 33 is defined below the piston 31.

The moving range of the work spindle 19 in the Z-axis direction is
Sleeve end 25a of aerostatic bearing 25 and sleeve end 36 of upper sleeve 36 fixed to cylinder tube 27
a in the axial direction.

The supply of the pressurized air to the air chamber 33 causes the work spindle 19 to float with respect to the housing 15, so that the self-weight of the work spindle 19 and the floating force of the pressurized air supplied to the air chamber 33 are generated. The lap pressure is variably set according to the equilibrium relationship.

An annular projection 37 for position detection is provided at an intermediate portion of the piston 31 in the axial direction. A lower limit proximity switch 39 for detecting that the work spindle 19 is located at the lower limit position due to the proximity of the annular projection 37 to the cylinder tube 27, and an upper limit for detecting that the work spindle 19 is located at the upper limit position. A proximity switch 41 is attached.

In the coupling housing 29, a plate piece member 45 fixedly connected to the upper end of the work spindle 19 by a pin 43, and a bearing motor 47 rotatably supported by the coupling housing 29 by a bush 49. A fork-like member 53, which is drivingly connected to the rotor shaft 51 and receives and engages the plate piece member 45 so as to be displaceable in the axial direction, is provided.
The pressure air is supplied from the air passage 55 to the air passage 3 to form an air static pressure coupling.

Next, a control system of the lapping machine will be described with reference to FIG.

The Z-axis coordinate position of the work spindle 19 detected by a position detector 63 such as a rotary encoder provided on the Z-axis servo motor 11 is input to the NC unit 61. The NC device 61 detects the workpiece spindle 1 from the position detector 63.
9, a signal indicating whether the work spindle 17 is located at the lower limit position is determined by the lower limit proximity switch 39, and a signal indicating whether the work spindle 17 is positioned at the upper limit position is determined by the upper limit proximity switch 41. Input the respective signals shown, execute the loaded NC programming, send a table rotation speed command to the table drive motor 5, a main shaft rotation speed command to the main shaft motor 21, a lap polishing amount command to the Z-axis servo motor 11, The lap pressure command is output to the electropneumatic regulator 65. The lap pressure command to the electropneumatic regulator 65 is performed by an analog signal based on the output of the D / A converter 69.

The electropneumatic regulator 65 includes a compressed air source 67
The pressure of the compressed air is adjusted to a value corresponding to the lap pressure command, and the compressed air after the pressure adjustment is supplied to the air passage 33 of the lapping work holding device 13.

The detection of the Z-axis coordinate position of the work spindle 19 can be performed by a Z-axis linear sensor according to required accuracy, in addition to the position detector 63.

Next, the quantitative lapping operation of the NC lapping machine having the above configuration will be described.

First, a work W such as a wafer is suction-held on the lower bottom surface of the work holding table 17, and the holding posture of the work W with respect to the table surface 3a of the lap table 3 is corrected by the fine tilt function of the work holding table 17.

When the work mounting operation is completed, NC programming is started and the Z-axis servo motor 11
The work holding device 13 for lapping is lowered together with the shaft slider 9.

The work W of the work holding table 17 comes into contact with the table surface 3a of the lap table 3 due to the lowering of the lapping work holding device 13, and the housing 15 is successively lowered by the lowering of the lapping work holding device 13. When the work spindle 19 is displaced upward and the work spindle 17 is separated from the lower limit position, the lower limit proximity switch 39 is set.
Output signal changes from on to off. The output signal of the position detector 63 at the time of this signal inversion is used as the workpiece contact position information (Z
(Axis coordinate value).

Thereafter, when the output signal of the upper limit proximity switch 41 changes from OFF to ON, the work spindle 19 is positioned at the upper limit position, and the Z-axis servo motor 11 lowers the lapping work holding device 13. Stop.

Next, a lap polishing amount command is given to the Z-axis servo motor 11, and the Z-axis servo motor 11 raises the lapping work holding device 13 together with the Z-axis slider 9 by the lap polishing amount according to the command value. As a result, the side of the housing 15 is displaced upward while leaving the work spindle 19 while the work W of the work holding table 17 is in contact with the table surface 3a of the lap table 3.

Next, the lap pressure command is given to the electropneumatic regulator 65, and the compressed air regulated according to the lap pressure command is supplied to the air chamber 35 of the main shaft floating means 23 through the air passage 33. As a result, the lap pressure is automatically set to the lap pressure command value instructed by NC programming based on the balance between the dead weight of the work spindle 19 and the levitation force applied to the work spindle 19 by the spindle levitation means 23.

Next, a table rotation speed command is given to the table drive motor 5 to rotate the lap table 3 with the table rotation speed command value specified by the NC programming, and a spindle speed command is given to the spindle motor 21 to work the workpiece. The spindle 19 is rotated with a spindle speed command value specified by NC programming.

With this, while the work W is being forcibly rotated, efficient lap polishing is performed with a predetermined lap pressure.

As the lap polishing progresses, the machining allowance of the work W is reduced, and the work spindle 1 and the work W are reduced.
9 descends under its own weight. When the lap polishing by the lap polishing amount command is completed, the work spindle 19 comes to the original lower limit position. When this is detected by the output signal of the lower limit proximity switch 39, that is, the output of the lower limit proximity switch 39 When the signal changes from off to on, the rotation of the table drive motor 5 and the main shaft motor 21 is stopped to stop the lap operation. This means that the fixed amount lapping process has been performed with the predetermined lap pressure.

Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to these embodiments, and various embodiments may be made within the scope of the present invention. The possibilities will be clear to the skilled person.

[0038]

As can be understood from the above description, according to the lapping work holding apparatus according to the first aspect, the work spindle is held by the work holding section by being rotationally driven by the spindle rotation driving means. The work is forcibly driven to rotate with the spindle speed, and the lap pressure is variably set according to the balance between the self-weight of the work spindle and the floating force given to the work spindle by the spindle levitation means. It is possible to automatically set the required value of the lap pressure without performing the lap pressure, and to variably set the lap pressure by automatic control.

According to the work holding device for lapping work according to the second aspect, the work held by the work holding portion of the work spindle contacts the lap table due to the lowering of the entire housing. The work spindle is displaced upward from the housing, and the work spindle separates from the lower limit position. This is detected by the lower limit position detecting means, and the Z-axis coordinate value at which the work contacts the lap table can be measured. The housing is lowered by the lap polishing amount from the Z-axis coordinate position of the lower limit position detection. By detecting the lowering of the work spindle to the lower limit position by the lower limit position detecting means, the lap polishing amount can be quantitatively controlled, and lap finishing by numerical control becomes possible.

According to the lapping machine according to the third aspect, the servo device controls the positioning of the vertical moving body and the lapping work holding device according to the invention attached to the vertically moving body, so that the lap polishing amount can be quantitatively determined. And lapping by numerical control becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a lapping machine according to the present invention.

FIG. 2 is a sectional view showing one embodiment of a lapping work holding device according to the present invention.

FIG. 3 is a front view showing a conventional lapping machine.

FIG. 4 is a plan view showing a conventional lapping machine.

[Explanation of symbols]

 Reference Signs List 3 lap table 5 table drive motor 7 Z-axis feed screw 9 Z-axis slider (vertical moving body) 11 Z-axis servo motor 13 Lapping work holder 15 Housing 17 Work holder 19 Work spindle 21 Spindle motor 23 Spindle lifting means 27 Cylinder tube 29 Coupling housing 31 Piston 35 Air chamber 37 Annular protrusion 39 Lower limit proximity switch 41 Upper limit proximity switch 45 Plate piece 51 Rotor shaft 53 Bifurcated member 61 NC device 63 Position detector 65 Electropneumatic regulator 67 Compressed air source

Claims (3)

[Claims] A housing supported by a vertically movable body driven in a vertical direction; a work spindle supported by the housing so as to be rotatable and vertically movable by a predetermined range and having a work holding portion at a lower end; A spindle rotating drive unit that rotationally drives the spindle; and a spindle floating unit that floats the work spindle in the ascending direction with respect to the housing, wherein the work spindle has its own weight and a floating force given by the spindle floating unit. A lap processing work holding device, wherein a lap pressure is variably set according to an equilibrium relationship. 2. The lapping work holding apparatus according to claim 1, further comprising lower limit position detecting means for detecting that the main spindle of the work is located at a lower limit position. 3. A lap table rotatably provided, a rotation driving means for driving the lap table to rotate, and a vertically movable part supporting the lap processing work holding device according to claim 1 or 2. A lapping machine comprising: a vertical moving body; and a servo device for positioning and driving the vertical moving body in a vertical direction.