JPH0627060U - Polishing equipment - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To supply a polishing device that can shorten the processing time by setting the processing pressure of the workpiece arbitrarily and prevent the pressure head from falling when the operation is stopped. [Structure] An air pressure source 16, a flow means 20 for causing air supplied from the air source 16 to flow into shunt channels 17, 18, 19, an electropneumatic conversion regulator 12 and a regulator 13 for adjusting the pressure of air, a passage and a shunt channel 17. , 18, a 5-port directional switching valve 11 for switching the connection relationship with the first and second passages is connected to the air pressure introducing chamber side 4a, and the second passage is connected to the air compression chamber side 4b. Pressurizing means for pressurizing the work 6 by the pressurizing head 3, block valves 8a, 8b connected to the branch passage 19 via the air passage 23 to open and close the air pressure introducing chamber side 4a and the compression chamber side 4b, The three-port directional switching valve 14 is provided between the branch flow passage 19 and the air passage 23 and operates the block valves 8a and 8b by switching the flow direction of air.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a polishing apparatus for polishing a work by pressing a work against a surface plate by a pressure head.

[0002]

[Prior art]

 When a work such as a semiconductor wafer is polished by a polishing apparatus, the polishing rate is faster as the processing pressure of the work is higher, and thus the work is generally polished under pressure.

It is suitable that the processing pressure per unit area of the workpiece during this processing is 100 to 400 gf / cm ² .

However, if the above-mentioned processing pressure is applied to the work from the start of processing, it will cause damage to the work, and it will be more accurate if the initial polishing is performed at a low pressure. Then, it was switched to processing pressure.

Incidentally, as a polishing apparatus, one shown in FIG. 3 is known.

That is, in the figure, 1 is a machine body, and the machine body 1 is provided with a surface plate 2. A pressure head 3 is provided on the upper surface of the surface plate 2, and the pressure head 3 is moved up and down by the vertical movement of the piston 7 of the drive cylinder 4.

A mounting plate 5 for holding the work 6 is provided on the lower end surface of the pressure head 3, and the work 6 is pressed by the surface plate 2 through the mounting plate 5 to be polished. There is.

The piston 7 of the drive cylinder 4 of this polishing apparatus is driven by an air pressure circuit as shown in FIG.

That is, reference numeral 16 in the drawing denotes an air pressure source, and a flow path 15 is connected to the air pressure source 16, and an electropneumatic conversion device for outputting an air pressure proportional to an input voltage is provided in the middle of the flow path 15. A regulator 12 is provided.

The P port of the 5-port directional control valve 11 is connected to the flow path 15.

The A port of the 5-port directional control valve 11 is connected to the air pressure introducing chamber side 4a of the drive cylinder 4 via the flow paths 10a and 7a, and the speed controller 9a is connected between the flow paths 10a and 7a. Is provided.

The B port of the 5-port directional control valve 11 is connected to the air compression chamber side 4b of the drive cylinder 4 via the flow paths 10b and 7b, and the speed controller 9b is provided between the flow paths 10b and 7b. It is provided.

The 5-port directional control valve 11 is a valve for raising or lowering the piston 7 of the drive cylinder 4. When the 5-port directional control valve 11 is switched to the a side, the piston 7 of the cylinder 4 lowers, It is designed to rise when switched to the b side.

The speed controllers 9a and 9b are valves that set the speed of the piston 7 of the drive cylinder 4 when moving up and down.

When pressurizing the pressurizing head 3 for processing, air pressure is supplied from the air pressure source 16, and this air pressure is sent to the electropneumatic conversion regulator 12 via the flow path 15. After the desired pressure is set here, the 5-port directional control valve 11 is switched to the side a and is introduced into the pneumatic pressure introducing chamber 4a side of the drive cylinder 4 via the speed controller 9a. It As a result, the piston 7 is pressed and lowered, and the pressure head 3 is lowered and the work 6 is pressed by the surface plate 2 and polished.

When the processing is completed, the 5-port directional switching valve 11 is switched to the b side and the air supplied from the air pressure source 16 is supplied to the air compression chamber of the drive cylinder 4 via the speed controller 9b. It is sent to the 4b side. As a result, the piston 7 rises and the pressure head 3 rises.

By the way, in the polishing apparatus configured as described above, the work 6 is processed by the processing sequence as shown in FIG.

In FIG. 5, Pa: Machining pressure during reduced pressure machining Pa ′: Machining pressure during self-weight machining Pb: Machining pressure during high pressure machining Pc: Pressure at which cleaning is performed at the end of machining the work, t1 to t4 indicates the switching set time by the timer.

[0019]

[Problems to be solved by the device]

 However, the above-mentioned circuit configuration has a drawback in that the processing pressure cannot be arbitrarily set during the self-weight processing and the processing time becomes long.

Further, when switching from the reduced pressure processing to the self-weight processing, the 5-port directional control valve 11 must be switched, and the processing pressure becomes stepwise. Therefore, particularly when the weight of the pressure head 3 or the like is large, the work 6 may be damaged.

Further, in this method, it is necessary to provide a means for preventing the pressure head 3 from dropping due to its own weight when the processing is stopped or the operation is stopped, and there is a problem that the structure becomes complicated.

Therefore, in the present invention, the processing pressure of the material to be polished can be arbitrarily set with a simple configuration to shorten the processing time of the material to be polished, and moreover, the pressure head drops when the operation is stopped. It is an object of the present invention to provide a polishing apparatus capable of preventing the above.

[0023]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention solves the above problems by providing an air pressure supply source, a flow means for flowing the air supplied from the air pressure supply source to the first to third branch channels, and first and second flow means. First and second pressure adjusting means for adjusting the pressure of the circulating air, which is provided in the shunt channel, and first and second passages connected to the first and second shunt channels of the circulation means. A first switching passage provided between the first and second passages and the first and second branch passages for switching the connection relationship between the first and second passages and the first and second branch passages. Of the drive cylinder is connected to the first passage, and the air compression chamber side is connected to the second passage, and is introduced to the air pressure introduction chamber side of the drive cylinder. A pressure means for operating the pressure head by air pressure to pressurize the material to be polished; First and second opening / closing for opening / closing the air pressure introducing chamber side and the air compression chamber side of the drive cylinder, which are respectively provided in the first and second passages and are connected to the third branch passage via an air passage. A valve is provided between the third branch flow passage and the air passage, and the first and second on-off valves are opened and closed by opening and closing the third branch passage and the air passage. And a second switching means for opening and closing.

[0024]

[Action]

 When processing is performed by pressurizing the pressurizing head, air is supplied from the air pressure supply source, the supplied air is branched into the first and second branch channels, and the divided atmospheric pressures are respectively divided into the first and second branch channels. After the pressure is adjusted by the second pressure adjusting means, the first switching means operates the switching operation to act on the pneumatic pressure introducing chamber side of the drive cylinder through the first passage, and also through the second passage. To the air compression chamber side of the drive cylinder. Simultaneous action of air pressure on the air pressure introducing chamber side and the air compression chamber side of the drive cylinder allows stepless adjustment of the pressurizing force of the pressurizing head by adjusting the air pressure by the first pressure adjusting means.

Further, when the processing is stopped, the operation of the second switching means closes the first and second opening / closing valves of the first and second flow passages, thereby cutting off the air pressure to and from the drive cylinder. The pressure head is fixedly held to prevent the pressure head from falling.

[0026]

【Example】

 The present invention will be described below with reference to an embodiment shown in FIGS.

In the figure, reference numeral 16 is an air pressure source as an air pressure supply means, and the air pressure source 16 is connected to a circulation means 20 composed of first to third branch channels 17, 18, and 19.

An electropneumatic conversion regulator 12 serving as a first pressure adjusting means for outputting an air pressure proportional to an input voltage is provided in the first branch flow channel 17, and a constant electric current is provided in the second branch flow channel 18. A regulator 13 as a second pressure adjusting means for setting the pressure is provided, and a three-port directional switching valve 14 as a second switching means is provided in the third branch passage 19.

The first and second branch channels 17 and 18 are respectively connected to the P port and the exhaust port EB of the 5-port directional switching valve 11 as the first switching means.

The A port of the 5-port directional control valve 11 is communicated with the pneumatic pressure introducing chamber side 4a of the drive cylinder 4 via the first passages 10a and 7a, and the first passages 7a and 10a are connected to each other by a switch. A speed controller 9a and a block valve 8a as a first opening / closing valve are provided.

The B port of the 5-port directional control valve 11 is communicated with the air compression chamber side 4b of the drive cylinder 4 constituting the pressurizing means via the second passages 7b and 10b, and the second passage A speed controller 9b and a block valve 8b as a second opening / closing valve are arranged between 7b and 10b.

The 5-port directional switching valve 11 is a valve for raising or lowering the piston 7 in the drive cylinder 4, and when the 5-port directional switching valve 11 is switched to the a side, the piston 7 of the cylinder 4 is moved. Is lowered, and when it is switched to side b, it is raised.

The speed controllers 9a and 9b are valves that set the speed at which the piston 7 of the drive cylinder 4 moves up and down.

The downstream of the 3-port directional control valve 14 is connected to the pilot ports PP of the block valves 8 a and 8 b via an air passage 23.

When the 3-port directional control valve 14 is not excited, it blocks the piston 7 of the cylinder 4 to prevent the pressure head 3 from dropping due to its own weight.

When the workpieces 6 are pressed, the 5-port directional control valve 11 is switched to the a side and the 3-port directional control valve 14 is excited.

As a result, the air pressure supplied from the air pressure source 16 is pressure-fed to the first to third branch channels 17 to 19, respectively. The air pressure pumped to the first branch passage 17 is set to a predetermined pressure by the electropneumatic conversion regulator 12.

The pneumatic pressure fed to the third branch passage 19 is sent to the pilot ports PP of the block valves 8a and 8b via the 3-port directional switching valve 14 to operate the 3-port directional switching valve 14. Then, the first passages 7a and 10a are communicated with each other, and the second passages 7b and 10b are communicated with each other.

The pneumatic pressure sent to the first branch flow passage 17 and set to a predetermined pressure by the electropneumatic conversion regulator 12 is the 5-port directional switching valve 11, the speed controller 9a and the block valve 8a. The air pressure is applied to the air pressure introducing chamber side 4a of the cylinder 4 via. By this pressurization, the piston 7 is lowered and the processing head 3 presses the wafers 6 ...

As the piston 7 descends, the air on the air compression side 4b in the cylinder 4 is compressed and discharged from the drive cylinder 4, and this air is discharged through the block valve 8b and the speed controller 9b to 5 It is sent to the port direction switching valve 11.

On the other hand, the air pressure fed from the air pressure source 16 to the second branch flow passage 18 is set to a constant air pressure by the regulator 13, and then pressurized by the 5-port directional control valve 11 to drive the cylinder 4. It acts on the inner air compression side 4b.

Here, the weight of the pressure head 3 and the piston 7 of the drive cylinder 4 and the like is L, the pressure receiving area of the pneumatic pressure introducing chamber side 4a of the drive cylinder 4 is Sh, the pressurizing force is Ph, and the air compression chamber side is the same. When the pressure receiving area of 4b is Sr, the pressing force is Pr, the area per workpiece is Sw, the number of workpieces is n, and the processing pressure per unit area of the workpiece is Pw, Pw = (L + Ph) -Sh-Pr-Sr) / n-Sw.

If the pressure Pr on the air compression chamber side set by the regulator 13 is set so as to be Pr · Sr = L, Pw = Ph · Sh / n · Sw during processing and Pw during processing is It is proportional to the pressure force Ph on the air pressure introduction side.

That is, Pw at the time of processing can be set from zero to stepless by adjusting the pressure Ph of the electropneumatic conversion regulator 12.

FIG. 2 shows an example of a processing pressure sequence, where Pa is a processing pressure during low-pressure processing, Pb is a processing pressure during high-pressure processing, Pc is a pressure when cleaning the workpiece at the end of processing, t1 to t3 indicate the switching set time by the timer.

A sensor for measuring the applied pressure is attached to the mounting shaft of the pressure head 3, the measured value from this sensor is compared with the preset value input, and the control signal corresponding to the deviation is sent to the above-mentioned electric signal. By controlling the processing pressure by outputting it to the air conversion regulator 12, it is possible to always apply the same processing pressure to each pressurizing head, thereby preventing the processing pressure from being varied among a plurality of pressing heads. However, the polishing precision by them can be made uniform, which is more preferable.

[0047]

[Effect of device]

 As described above, according to the present invention, the air pressure supplied by the air pressure supply means is adjusted by the first pressure adjusting means to be introduced into the air pressure introducing chamber side of the drive cylinder, and the air pressure of the drive cylinder is changed. Since the air pressure whose pressure has been adjusted by the second pressure adjusting means is applied to the compression chamber side through the first switching means, it is driven by the drive cylinder by adjusting the pressure by the first pressure adjusting means. The pressure of the pressure head can be set steplessly.

Therefore, it is possible to easily select a processing sequence that can shorten the processing time of the material to be polished.

Further, since it is not necessary to switch the first switching means when switching the processing pressure, smooth switching is possible, and the cause such as damage to the material to be polished can be eliminated.

Further, since the opening / closing valve closes the air compression chamber side of the drive cylinder, it is possible to prevent the pressure head from falling due to its own weight when the operation is stopped.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a pneumatic circuit of a polishing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a processing sequence of the polishing apparatus shown in FIG.

FIG. 3 is a partial cross-sectional side view showing a conventional polishing apparatus.

4 is a configuration diagram showing a pneumatic circuit of the polishing apparatus of FIG.

FIG. 5 is a diagram showing an example of a conventional processing sequence.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Machine body, 2 ... Surface plate, 3 ... Pressurizing head, 4 ... Driving cylinder (pressurizing means), 5 ... Mounting plate, 6 ... Work (material to be ground), 7a, 10a ... Flow path (1st path) ), 8a, 8b ... Block valves (first and second opening / closing valves), 9a, 9b ... Speed controller, 7b,
10b ... Flow path (second passage), 11 ... 5-port directional switching valve (first switching means), 12 ... Electropneumatic conversion regulator (first pressure adjusting means), 13 ... Regulator (second pressure adjustment) Means), 14 ... 3-port directional switching valve (second switching means), 15 ... flow path, 16 ... air pressure source (air pressure supply source), 17 ... first branch flow path, 18 ... second branch flow path, 19
… Third branch channel, 20… Distribution means.

Claims (1)

[Scope of utility model registration request] 1. An air pressure supply source, circulation means for causing air supplied from this air pressure supply source to flow through the first to third branch channels, and circulation means provided in the first and second branch channels of this circulation means. First and second pressure adjusting means for adjusting the pressure of the air to be supplied, first and second passages connected to the first and second branch passages of the circulating means, and the first and second passages. First switching means provided between the passage and the first and second branch channels to switch the connection relationship between the first and second channels and the first and second branch channels; The air pressure introducing chamber side of the drive cylinder is connected to the passage, the air compression chamber side is connected to the second passage, and the pressurizing head is operated by the air pressure introduced to the air pressure introducing chamber side of the drive cylinder. Pressing means for pressurizing the material to be polished, and the first and second First and second opening / closing valves respectively provided in the passages and connected to the third branch passage via an air passage to open / close the air pressure introducing chamber side and the air compression chamber side of the drive cylinder; The third passage is provided between the branch passage and the air passage.
And a second switching means for operating the first and second opening / closing valves by opening / closing between the branch passage and the air passage.