Gas-liquid separation device and processing device

Abstract

To provide a gas-liquid separation device which prevents waste liquid suctioned by a workpiece holding surface from flowing into a suction source, and a processing apparatus.SOLUTION: A control unit (150) opens an upper tank waste liquid valve (116), closes a lower tank waste liquid valve (120), closes a take-in valve (118), makes liquid of the fluid mixture in an upper tank (111) flow down to a lower tank (112) with the self-weight of the liquid, performs gas-liquid separation so as to prevent a suction source (130) from suctioning the liquid, closes the upper tank waste liquid valve (116) when draining the liquid flowing down to the lower tank (112), opens the lower tank waste liquid valve (120), opens the take-in valve (118), and drains the liquid in the lower tank (112).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gas-liquid separation device and a processing device.

Background Art

[0002] In the manufacturing process of semiconductor wafers, the wafer, which is the workpiece, is divided into chips by a cutting device or the like, and the back surface opposite to the surface on which the device is formed is ground by a grinding device to a predetermined thickness. As a processing device capable of removing the unevenness of the ground back surface and increasing the flexural strength, a processing device capable of polishing the workpiece by a chemical mechanical polishing method, so-called CMP (Chemical Mechanical Polishing), is used.

[0003] In the processing device of Patent Document 1, a chuck table for sucking and holding the workpiece is disposed on the lower side, and grinding means and polishing means are disposed on the upper side. Then, when polishing the workpiece after grinding, while supplying slurry (polishing liquid) to the workpiece, the polishing pad is pressed against the workpiece for polishing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the case of a CMP polishing device in which a processing device supplies polishing liquid to polish a workpiece, the holding surface holding the workpiece sucks slurry from the outer periphery of the workpiece. The sucked slurry is sucked into a suction source through a communication path and drained. In order to suck the slurry in this way, there are also problems such as wear of the fins of the pump by the abrasive grains contained in the slurry and corrosion of the fins of the pump by acidic or alkaline slurry.

[0006] Furthermore, when a workpiece is held in place by suction at the holding surface, water is drawn in from the outer circumference of the workpiece. As a result, a large amount of water flows into the suction channel, reducing the suction force and making it impossible to hold the workpiece in place. Therefore, a configuration is required that prevents liquids such as wastewater from flowing into the suction source.

[0007] This invention has been made in view of the above, and aims to prevent the liquid drawn in by the workpiece holding surface from flowing into the suction source. [Means for solving the problem]

[0008] A gas-liquid separation apparatus according to one aspect of the present invention is a gas-liquid separation apparatus that sucks a mixed fluid of liquid and gas from a suction section, places the apparatus between the suction section and a suction source, and separates the sucked mixed fluid into liquid and gas, comprising: an upper tank; a lower tank placed below the upper tank; an upper tank drain valve that connects or disconnects the lower part of the upper tank and the upper part of the lower tank; a lower tank drain valve located at the lower part of the lower tank that opens and closes; an intake valve located at the upper part of the lower tank that opens and closes to allow intake of atmospheric air; and a control unit, wherein the upper tank is in communication with the suction section and also in communication with the suction source. The lower tank is equipped with an upper water level sensor at the top. The control unit opens the upper tank drain valve, closes the lower tank drain valve, closes the intake valve, and creates the same negative pressure in the upper and lower tanks, causing the liquid of the mixed fluid in the upper tank to flow down into the lower tank by its own weight, thereby separating the gas and liquid so as not to draw the liquid into the suction source. When the upper water level sensor detects the liquid that has flowed down and accumulated in the lower tank, Close the upper tank drain valve, open the lower tank drain valve, open the intake valve, and create negative pressure inside the upper tank, and the upper tank to Therefore, the system is characterized by making it possible to drain the liquid from the lower tank by bringing the pressure inside the lower tank to atmospheric pressure while keeping the mixed fluid in a state where it can be sucked out.

[0009] This invention Another The gas-liquid separation apparatus of the form is A gas-liquid separation device that draws a mixed fluid of liquid and gas from a suction unit, places the device between the suction unit and a suction source, and separates the drawn mixed fluid into liquid and gas, comprising: an upper tank; a lower tank placed below the upper tank; an upper tank drain valve that connects or disconnects the lower part of the upper tank and the upper part of the lower tank; a lower tank drain valve located at the lower part of the lower tank that opens and closes; an intake valve located at the upper part of the lower tank that opens and closes to allow intake of air; and a control unit, wherein the upper tank is in communication with the suction unit and the suction source, the lower tank is equipped with a lower water level sensor at its lower part, and the control unit opens the upper tank drain valve, closes the lower tank drain valve, closes the intake valve, and sets the upper tank and the lower tank to the same negative pressure. The system is designed to separate the liquid from the mixed fluid in the tank by its own weight, allowing the liquid to flow down into the lower tank, preventing the liquid from being drawn into the suction source; when discarding the liquid that has flowed down into the lower tank, the upper tank drain valve is closed, the lower tank drain valve is opened, the intake valve is opened, negative pressure is created in the upper tank, allowing the mixed fluid to be drawn into the upper tank, while atmospheric pressure is maintained in the lower tank, allowing the liquid in the lower tank to be discarded; and when the lower water level sensor no longer detects the liquid that has flowed down into the lower tank, the upper tank drain valve is opened, the lower tank drain valve is closed, the intake valve is closed, and the upper and lower tanks are subjected to the same negative pressure, enabling the liquid in the upper tank to flow down into the lower tank by its own weight. It is characterized by the following:

[0010] Furthermore, the aboveOne embodiment of the gas-liquid separation apparatus is characterized in that the lower tank is equipped with a lower water level sensor at its bottom, and when the lower water level sensor no longer detects the liquid that has flowed down into the lower tank, the upper tank drain valve is opened, the lower tank drain valve is closed, and the intake valve is closed, creating the same negative pressure in the upper tank and the lower tank, thereby allowing the liquid in the upper tank to flow down into the lower tank by its own weight. Furthermore, the gas-liquid separation apparatus of the other embodiment described above is characterized in that the lower tank is equipped with an upper water level sensor at its top, and when the upper water level sensor detects liquid that has flowed down into the lower tank and accumulated, the control unit closes the upper tank drain valve, opens the lower tank drain valve, and opens the intake valve.

[0011] A processing apparatus according to one aspect of the present invention is characterized by comprising the above-mentioned gas-liquid separation device, a chuck table that holds a workpiece on its holding surface, a suction source that serves as a suction source, and a liquid supply unit that supplies liquid to the workpiece. [Effects of the Invention]

[0012] The present invention provides a gas-liquid separation device and a processing device that prevent liquids such as wastewater sucked up by the workpiece holding surface from flowing into the suction source. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view showing the configuration of a gas-liquid separation device and a processing device according to an embodiment. [Figure 2] This is a schematic diagram showing the configuration of the gas-liquid separation device and suction source according to this embodiment. [Modes for carrying out the invention]

[0014] The gas-liquid separation apparatus and processing apparatus according to this embodiment will be described below with reference to the attached drawings. Figure 1 is a perspective view showing the configuration of the gas-liquid separation apparatus and processing apparatus according to this embodiment. Figure 2 is a schematic diagram showing the configuration of the gas-liquid separation apparatus and suction source according to this embodiment.

[0015] The X-axis direction, Y-axis direction, and Z-axis direction shown in each figure are perpendicular to each other. The X-axis direction and Y-axis direction are substantially horizontal directions, and the Z-axis direction is the vertical (up and down) direction. In each figure, of the double-headed arrows indicating the X-axis direction, the side with the letter X attached is taken as the left side, and the side without the letter X attached is taken as the right side. Of the double-headed arrows indicating the Y-axis direction, the side with the letter Y attached is taken as the front side, and the side without the letter Y attached is taken as the back side. Of the double-headed arrows indicating the Z-axis direction, the side with the letter Z attached is taken as the upper side, and the side without the letter Z attached is taken as the lower side.

[0016] As shown in FIG. 1, the processing apparatus 1 is configured to press the polishing pad 40 of the polishing mechanism 30 against the workpiece on the chuck table 10 and relatively rotate the chuck table 10 and the polishing pad 40 while supplying slurry as a polishing liquid. In such chemical mechanical polishing (CMP), the workpiece is etched by the chemical components of the polishing liquid, and the workpiece is mechanically polished by the abrasive grains dispersed on the polishing pad 40. The processing apparatus 1 is connected to a suction source 130 that sucks and holds the workpiece and a gas-liquid separation device 100 that separates the mixed fluid sucked during suction and holding.

[0017] The workpiece is a wafer formed in a substantially disk shape. Note that the workpiece may be any plate-shaped work to be polished, such as a semiconductor substrate such as silicon or gallium arsenide, an inorganic material substrate such as ceramic, glass, or sapphire, or even a package substrate of a semiconductor product.

[0018] The processing apparatus 1 has a base 2 in a substantially rectangular parallelepiped shape. A table support base 11 that supports the chuck table 10 is provided. The table support base 11 supports the chuck table 10 so as to be rotatable. The chuck table 10 has a disk shape and is provided so as to be rotatable about the disk center by the table support base 11. The processing apparatus 1 includes a liquid supply unit 60 that supplies slurry to the polishing mechanism 30 and the workpiece held by the chuck table 10.

[0019] The upper surface of the chuck table 10 has a holding member 13. The holding member 13 is made of, for example, a porous ceramic material. The surface of the holding member 13 is a suction portion 15 that sucks and holds the workpiece. The suction portion 15 obtains a suction force from a suction source 130.

[0020] The suction portion 15 of the chuck table 10 communicates with the suction source 130 via a first suction passage 113, a gas-liquid separation device 100, and a second suction passage 114, which will be described later. The workpiece is sucked and held by the suction portion 15 through a protective tape.

[0021] Also, when sucking and holding the workpiece, slurry (polishing liquid) supplied from a liquid supply portion 60, which will be described later, is also sucked from the outer periphery of the workpiece.

[0022] The table support base 11 of the chuck table 10 is connected to the movable plate 23 of the drive mechanism 20, and slides within an opening 3 formed on the upper surface of the base 2 by the driving force supplied from this drive mechanism 20. As a result, the chuck table 10 slides between a loading / unloading position for supplying the workpiece before processing and collecting the workpiece after processing, and a polishing position where the polishing mechanism 30 and the workpiece face each other. Note that the opening 3 is covered with a bellows-shaped dust cover 4.

[0023] The drive mechanism 20 has a pair of guide rails 22 parallel to the Y-axis direction disposed on a drive base 21, and a motor-driven movable plate 23 slidably installed on the pair of guide rails 22. A nut portion 24 is formed on the back side of the processing device 1, and a ball screw 25 is screwed into this nut portion 24. When a drive motor 26 connected to one end of the ball screw 25 is rotationally driven, the movable plate 23 is moved in the Y-axis direction along the pair of guide rails 22.

[0024] The column 31 is provided with a drive mechanism 32 for moving the polishing mechanism 30 up and down. The drive mechanism 32 has a pair of guide rails 33 arranged on the front of the column 31 and parallel to the Z-axis direction, and a motor-driven Z-axis table 34 that is slidably mounted on the pair of guide rails 33. The polishing mechanism 30 is supported on the front of the Z-axis table 34 via a housing 35. A ball screw (not shown) is screwed onto the back of the Z-axis table 34, and a drive motor 37 is connected to one end of the ball screw. The drive motor 37 rotates the ball screw, causing the polishing mechanism 30 to move along the guide rails 33 in the Z-axis direction.

[0025] A mount 39 is provided at the lower end of the spindle 38 of the polishing mechanism 30, and a polishing pad 40 is attached to the lower surface of the mount 39. The polishing surface 41 of the polishing pad 40 is located on a surface facing the chuck table 10 above.

[0026] The liquid supply unit 60 supplies liquid to the workpiece. The liquid is not particularly limited, but may be, for example, a slurry (polishing fluid) or any other liquid supplied as needed during processing. The polishing surface 41 of the polishing pad 40 is provided with a liquid discharge port (not shown) for supplying liquid to the workpiece held by the chuck table 10. The liquid is supplied from the liquid supply source 61 through the flow path 62.

[0027] The control unit 150 controls each of the above-mentioned components that make up the processing device 1, causing the processing device 1 to perform processing operations on the workpiece. The control unit 150 is mainly composed of a microprocessor equipped with, for example, a CPU, ROM, RAM, etc. The control unit 150 is connected to a display unit (not shown) that displays the status of the processing operation, and an input unit (not shown) used by the operator to register processing content information, etc.

[0028] Figure 2 is a schematic diagram showing the configuration of the gas-liquid separation device and suction source in this embodiment. Figure 2 provides a detailed explanation of the gas-liquid separation device 100 and suction source 130 shown in Figure 1, but it is assumed that any components not shown in Figure 2 that are normally present in the processing device 1 are also included.

[0029] The gas-liquid separation device 100 is positioned between the suction unit 15 and the suction source 130 and consists of a tank 110 that separates the aspirated slurry into gas and liquid and discharges the liquid. The tank 110 consists of an upper tank 111 and an upper tank 111 It consists of a lower tank 112 located below it. The gas-liquid separator 100 is connected to the drain port 140.

[0030] The upper tank 111 is in communication with the suction section 15 of the chuck table 10 via the first suction passage 113.

[0031] The first suction passage 113 is located at any position on the upper part of the upper tank 111. The mixed fluid drawn in by the suction section 15 enters the upper tank 111.

[0032] The upper tank 111 is in communication with the suction source 130 via the second suction passage 114. The second suction passage 114 is in communication with the upper tank 111 It is located at any position on the upper part.

[0033] Alternatively, a partition plate may be placed inside the upper tank 111, leaving a gap in front of the connection port of the second suction passage 114. This partition plate prevents the second suction passage 114 from directly drawing in the mixed fluid drawn from the first suction passage 113 into the upper tank 111, thereby separating the liquid and gas within the upper tank 111.

[0034] An upper tank drainage channel 115 is provided at the bottom of the upper tank 111, and it communicates with the top of the lower tank 112 via the upper tank drainage channel 115. An upper tank drainage valve 116 is also provided in the upper tank drainage channel 115, and the upper tank drainage valve 116 connects or disconnects the upper tank 111 and the lower tank 112. The upper tank drainage valve 116 is controlled by the control unit 150.

[0035] The upper tank drainage channel 115 may also be a communication port connecting the lower plate of the upper tank 111 and the upper plate of the lower tank 112. The upper tank drainage valve 116 may be placed at the communication port.

[0036] The lower tank 112 is configured such that drainage flows down from the upper tank drainage channel 115, which is connected to the upper part of the lower tank 112. An outside air intake channel 117 is provided at any position on the upper part of the lower tank 112. In addition, the outside air intake channel 117 has Tori A loading valve 118 is provided. Tori The intake valve 118 connects or disconnects the lower tank 112 from the outside (outside air). Tori The intake valve 118 is controlled by the control unit 150.

[0037] A lower tank drainage channel 119 is provided at the bottom of the lower tank 112, and it communicates with the drain port 140 via the lower tank drainage channel 119. A lower tank drainage valve 120 is also provided in the lower tank drainage channel 119, and the lower tank drainage valve 120 connects or disconnects the lower tank 112 and the drain port 140. The lower tank drainage valve 120 is controlled by the control unit 150.

[0038] The lower tank 112 is equipped with an upper water level sensor 121 and a lower water level sensor 122, which sense the water level of the liquid stored in the lower tank 112. The sensed water level is transmitted to the control unit 150, which controls the opening and closing of each valve based on the sensed water level.

[0039] The suction source 130 applies suction force to the suction section 15 of the chuck table 10 via the first suction passage 113, the upper tank 111, and the second suction passage 114. The suction source 130 is controlled by the control unit 150. The suction source 130 is also connected to the drain port 140 via the drain passage 131, and when the suction source 130 draws in liquid from the mixed fluid, it drains the liquid into the drain port 140. The suction source 130 used is not particularly limited, but it is preferable to use a vacuum pump. It is even more preferable to use a water-sealed vacuum pump.

[0040] The drain port 140 drains the liquid that flows in from the lower tank 112 and the suction source 130. The drained liquid is then sent to the drainage treatment facility 141 for treatment.

[0041] Next, using Figure 2, the operation of the gas-liquid separation device 100 according to this embodiment in separating a mixed fluid into liquid and gas will be explained.

[0042] The mixed fluid is described below. The mixed fluid is a mixture of the gas drawn in by the suction unit 15 during suction and holding, and a liquid containing slurry and solid materials (abrasive particles, machining debris). The liquid containing slurry and solid materials (abrasive particles, machining debris) is treated as wastewater.

[0043] During the polishing process of the processing apparatus 1, the suction source 130 is activated, creating negative pressure inside the upper tank 111, and generating suction force at the suction section 15 of the chuck table 10. At this point, a mixed fluid of gas and liquid is drawn into the suction section 15. The drawn-in mixed fluid flows into the upper tank 111 via the first suction passage 113. In this state, the upper tank drain valve 116 is closed, and the liquid of the mixed fluid is stored in the upper tank 111.

[0044] A second suction passage 114, connected to the suction source 130, is located at the top of the upper tank 111. Gas flows into the second suction passage 114, but liquid is stored at the bottom of the upper tank 111, making it difficult for liquid to flow into the second suction passage 114.

[0045] The control unit 150 opens the upper tank drain valve 116, closes the lower tank drain valve 120, and closes the intake valve 118.

[0046] As a result, the air pressure inside the upper tank 111 and the lower tank 112 becomes the same negative pressure. The liquid in the upper tank 111 flows down into the lower tank 112 due to its own weight. This allows for gas-liquid separation without drawing the liquid into the suction source 130.

[0047] The following describes the treatment of the wastewater that flows down into the lower tank 112. When the upper water level sensor 121 detects the liquid that has flowed down into the lower tank 112 and accumulated, the upper tank drain valve 116 is closed, the lower tank drain valve 120 is opened, and the intake valve 118 is opened.

[0048] As a result, the upper tank 111 becomes negatively pressurized, while the lower tank 112 becomes atmospheric pressure. In this state, the upper tank 111 is capable of drawing in the mixed fluid and is storing the liquid. The lower tank 112 is in a state of drainage. The liquid is drained from the lower tank drainage channel 119 to the drain port 140 of the lower tank 112.

[0049] When the lower water level sensor 122 no longer detects liquid flowing into the lower tank 112, the upper tank drain valve 116 is opened, the lower tank drain valve 120 is closed, and the intake valve 118 is closed.

[0050] As a result, the air pressure inside the upper tank 111 and the lower tank 112 becomes the same negative pressure. The liquid that enters the upper tank 111 flows down into the lower tank 112 again due to its own weight.

[0051] The gas-liquid separation device and processing device according to this embodiment, through the configuration and series of operations described above, do not allow liquids such as wastewater to be drawn into the suction source 130, thus preventing damage to the suction source from liquids such as wastewater and solid matter (abrasive particles, processing debris) contained in the liquid.

[0052] Furthermore, the valve opening and closing operations of the control unit 150 may be configured to be controlled by pre-setting the water levels detected by the upper water level sensor 121 and the lower water level sensor 122. Alternatively, the valve opening and closing operations may be pre-set to occur at pre-set times. By setting the valve opening and closing operations in this way, drainage treatment can be automated.

[0053] Although the above embodiment was applied to a polishing apparatus, the processing apparatus to which the present invention can be applied is not limited to polishing apparatuses. For example, it can be applied to all types of processing apparatus that suck up a mixed fluid of liquid and gas from a suction section, such as grinding apparatuses and cutting apparatuses. [Industrial applicability]

[0054] As described above, the gas-liquid separation device and processing device according to this embodiment prevent liquids such as wastewater drawn in by the workpiece holding surface from flowing into the suction source. This is particularly useful in the semiconductor manufacturing field, which includes a process of polishing the workpiece. [Explanation of symbols]

[0055] 1: Processing equipment 2: Base 3: Opening 4: Dust cover 10: Chuck Table 11: Table support stand 13: Holding surface 15: Suction part 20: Drive mechanism 21: Drive base 22: Guide rail 23: Movable plate 24: Nut part 25: Ball screw 26: Drive motor 30: Grinding mechanism 31: Column 32: Drive mechanism 33: Guide rail 34: Z-axis table 35: Housing 37: Drive motor 38: Spindle 39: Mount 40: Polishing pad 41: Polished surface 60:Liquid supply section 61 :Liquid supply source 62: Flow path 100: Gas-liquid separation equipment 110: Tank 111: Upper Tank 112: Lower Tank 113: 1st suction path 114:Second suction path 115: Upper tank drainage channel 116: Upper tank drain valve 117: Outside air intake channel 118: Tori Recessed valve 119: Lower tank drainage channel 120: Lower tank drain valve 121: Upper water level sensor 122: Sewer level sensor 130: Suction source 131: Drainage channel 140: Drain port 141: Wastewater treatment equipment 150: Control Unit

Claims

1. A gas-liquid separation device that draws a mixed fluid of liquid and gas from a suction unit, places it between the suction unit and a suction source, and separates the drawn mixed fluid into liquid and gas, Upper tank and A lower tank is placed below the upper tank, An upper tank drain valve that connects or disconnects the lower part of the upper tank and the upper part of the lower tank, A lower tank drain valve, which is located at the bottom of the lower tank and opens and closes, An intake valve is positioned at the top of the lower tank and opens and closes to allow air to be taken in, It comprises a control unit and, The upper tank is in communication with the suction section and also with the suction source. The lower tank is equipped with an upper water level sensor at the top. The control unit is The upper tank drain valve is opened, the lower tank drain valve is closed, the intake valve is closed, the upper tank and the lower tank are subjected to the same negative pressure, causing the liquid of the mixed fluid in the upper tank to flow down into the lower tank by its own weight, thereby separating the gas and liquid without drawing the liquid into the suction source. When the upper water level sensor detects the liquid that has flowed down and accumulated in the lower tank, A gas-liquid separation device that closes the drain valve of the upper tank, opens the drain valve of the lower tank, opens the intake valve, creates negative pressure inside the upper tank so that the mixed fluid can be drawn out by the upper tank, and brings the inside of the lower tank to atmospheric pressure so that the liquid in the lower tank can be discarded.

2. The lower tank is equipped with a lower water level sensor at the bottom, When the lower water level sensor no longer detects the liquid that has flowed into the lower tank, Open the upper tank drain valve, close the lower tank drain valve, and close the intake valve. The gas-liquid separation apparatus according to claim 1, wherein the upper tank and the lower tank are under the same negative pressure, thereby enabling the liquid in the upper tank to flow down into the lower tank by its own weight.

3. A gas-liquid separation device that draws a mixed fluid of liquid and gas from a suction unit, places it between the suction unit and a suction source, and separates the drawn mixed fluid into liquid and gas, Upper tank and A lower tank is placed below the upper tank, An upper tank drain valve that connects or disconnects the lower part of the upper tank and the upper part of the lower tank, A lower tank drain valve, which is located at the bottom of the lower tank and opens and closes, An intake valve is positioned at the top of the lower tank and opens and closes to allow air to be taken in, It comprises a control unit and, The upper tank is in communication with the suction section and also with the suction source. The lower tank is equipped with a water level sensor at the bottom. The control unit is The upper tank drain valve is opened, the lower tank drain valve is closed, the intake valve is closed, the upper tank and the lower tank are subjected to the same negative pressure, causing the liquid of the mixed fluid in the upper tank to flow down into the lower tank by its own weight, thereby separating the gas and liquid without drawing the liquid into the suction source. When disposing of the liquid that has flowed down into the lower tank, The upper tank drain valve is closed, the lower tank drain valve is opened, the intake valve is opened, negative pressure is created inside the upper tank so that the mixed fluid can be drawn out by the upper tank, the lower tank is brought to atmospheric pressure, and the liquid in the lower tank is discarded. When the lower water level sensor no longer detects the liquid that has flowed into the lower tank, Open the upper tank drain valve, close the lower tank drain valve, and close the intake valve. A gas-liquid separation device that creates the same negative pressure in the upper tank and the lower tank, thereby enabling the liquid in the upper tank to flow down into the lower tank by its own weight.

4. The lower tank is equipped with an upper water level sensor at the top, When the upper water level sensor detects liquid that has flowed down into the lower tank and accumulated, the control unit will: The gas-liquid separation apparatus according to claim 3, wherein the upper tank drain valve is closed, the lower tank drain valve is opened, and the intake valve is opened.

5. A processing apparatus comprising a gas-liquid separation device according to any one of claims 1 to 4, a chuck table for holding a workpiece with a holding surface, a vacuum pump for serving as a suction source, and a liquid supply unit for supplying liquid to a workpiece.

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