Pressure control valve

Abstract

To provide a pressure control valve capable of controlling control pressure with higher accuracy.SOLUTION: A pressure control valve (electropneumatic regulator 1) includes a primary flow path 11 on an upstream side, a secondary flow path 12 on a downstream side, a supply valve part (supply valve 26) for supplying a control fluid from the primary flow path 11 to the secondary flow path 12, an exhaust valve part (exhaust valve 27) for exhausting the control fluid in the secondary flow path 12, and a pilot chamber 35 to and from which a pilot fluid for driving the supply valve part (supply valve 26) and the exhaust valve part (exhaust valve 27) is supplied and exhausted. The air supply valve part (air supply valve 26) and the air discharge valve part (air discharge valve 27) are positioned with the primary side flow path 11 interposed therebetween, the air discharge valve part (air discharge valve 27) includes the air discharge chamber 271 communicating with the outside of the pressure control valve (electropneumatic regulator 1) in order to discharge air, and the air discharge chamber 271 is positioned on the opposite side (for example, the upper side in FIG. 2) of the air supply valve part (air supply valve 26) of the air discharge valve part (air discharge valve 27).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pressure control valve. [Background technology]

[0002] A CMP device is a device used to polish wafer surfaces by generating a polishing action using a slurry between a polishing pad and the wafer surface, resulting in a precise planarization of the wafer surface. This polishing process requires a pressure to press the wafer against the polishing pad, and this pressure is obtained by air pressure. A pressure control valve is used to adjust this air pressure (i.e., to adjust the pressure).

[0003] A known example of a pressure control valve is the electropneumatic regulator described in Patent Document 1. The electropneumatic regulator described in Patent Document 1 will now be described with reference to Fig. 11. Fig. 11 is a cross-sectional view of an electropneumatic regulator 100 according to the prior art.

[0004] (Configuration of pressure control valve according to prior art) First, we will explain the configuration of electropneumatic regulator 100. Electropneumatic regulator 100 includes a primary flow path 110 on the upstream side, a secondary flow path 120 on the downstream side, an exhaust port 150 for exhausting the secondary flow path 120, an intake valve 260 arranged between primary flow path 110 and secondary flow path 120, an exhaust valve 270 arranged between secondary flow path 120 and exhaust port 150, and a pilot chamber 350 for operating intake valve 260 and exhaust valve 270.

[0005] The primary side flow path 110 and the secondary side flow path 120 are connected via a connecting flow path 140 and a feedback chamber 130, and the electropneumatic regulator 100 is capable of controlling the pressure of the control fluid that flows in from the primary side flow path 110 and is output from the secondary side flow path 120 by operating an intake valve 260 and an exhaust valve 270.

[0006] Air intake valve 260 includes valve seat 160, valve element 411, and compression spring 230. Valve seat 160 is provided along the open end of communication flow path 140. Valve element 411 is provided integrally with movable shaft 61 and comes into contact with or separates from valve seat 160. A bottom plug 250 is threadedly attached to the underside of electropneumatic regulator 100 via an O-ring 240. Compression spring 230 is compressed between valve element 411 of movable shaft 61 and bottom plug 250, and constantly applies a biasing force to valve element 411 in the direction of valve seat 160.

[0007] A bottom rubber 220 is arranged on the inner circumferential side of the compression spring 230 so as to cover the movable shaft 61. The bottom rubber 220 is a compressible and deformable member made of NBR or the like. The bottom rubber 220 is arranged between the valve body 411 and the bottom plug 250 in a state of tight contact with the valve body 411 and the bottom plug 250, and prevents fluid from leaking from gaps between the bottom plug 250 and the movable shaft 61, etc.

[0008] The bottom plug 250 is provided with an exhaust port 150. In addition, the movable shaft 61 has a cylindrical shape with a hollow hole 610. Furthermore, the movable shaft 61 is inserted into the communication flow path 140 so that its upper end in the figure is disposed in the feedback chamber 130 and its lower end in the figure is disposed within the bottom plug 250. With the above-mentioned configuration, the feedback chamber 130 communicates with the exhaust port 150 via the hollow hole 610.

[0009] The exhaust valve 270 includes a valve seat surface 412 and a steel ball 340. The valve seat surface 412 is provided on the upper end surface of the movable shaft 61 in the figure. The steel ball 340 is a valve element that is provided so as to be able to come into contact with or separate from the valve seat surface 412. The steel ball 340 is held by a diaphragm assembly 310, which will be described later, and moves up and down in the figure in accordance with the displacement of the diaphragm 320.

[0010] The diaphragm assembly 310 includes a diaphragm 320, a relief sheet 330, and a steel ball 340. The outer edge of the diaphragm 320 is clamped and fixed, airtightly separating the feedback chamber 130 and the pilot chamber 350. The relief sheet 330 is a rigid member such as metal, and is attached integrally to the pressure-receiving surface side of the diaphragm 320 (the surface located on the lower side in the figure). The relief sheet 330 holds the steel ball 340 in a position facing the valve seat surface 412.

[0011] (Regarding the operation of pressure control valves according to the prior art) Next, the operation of the electropneumatic regulator 100 will be described.

[0012] First, the operation when increasing the pressure (control pressure) of the control fluid output from the secondary flow path 120 will be described. Increasing the control pressure means that the control pressure is lower than the target pressure (set control pressure). In this case, the electropneumatic regulator 100 supplies pilot air to the pilot chamber 350, increasing the pressure within the pilot chamber 350. When the pressure within the pilot chamber 350 becomes higher than the pressure within the feedback chamber 130 (i.e., the control pressure), the diaphragm 320 is displaced toward the feedback chamber 130 (downward in the figure). As a result, the steel ball 340 is pressed against the valve seat surface 412 in the same direction as the displacement of the diaphragm 320 (downward in the figure), and the exhaust valve 270 is closed. When the downward force acting on the valve seat surface 412 in the figure becomes greater than the spring force of the compression spring 230 and the elastic force of the bottom rubber 220, the movable shaft 61 moves downward in the figure in response to the displacement of the diaphragm 320, compressing the compression spring 230 and the bottom rubber 220. As a result, the valve element 411 provided on the movable shaft 61 moves away from the valve seat 160, and the intake valve 260 opens. As a result, the control fluid supplied to the primary-side flow path 110 is supplied to the secondary-side flow path 120 via the communication flow path 140 and the feedback chamber 130. This causes the control pressure to increase.

[0013] Next, the operation when the pressure (control pressure) of the control fluid output from the secondary-side flow path 120 is reduced will be described. Reducing the control pressure refers to when the control pressure is higher than the target pressure (set control pressure). In this case, the electropneumatic regulator 100 exhausts pilot air from the pilot chamber 350, reducing the pressure inside the pilot chamber 350. When the pressure in the pilot chamber 350 becomes lower than the pressure in the feedback chamber 130 (i.e., the control pressure), the diaphragm 320 is displaced toward the pilot chamber 350 (upward in the figure). Then, the movable shaft 61 moves upward in the figure following the diaphragm 320 due to the combined force of the spring force of the compression spring 230 and the restoring force of the bottom rubber 220. When the movable shaft 61 moves and the valve element 411 abuts against the valve seat 160, the intake valve 260 is closed. This stops the supply of control fluid from the primary-side flow path 110 to the secondary-side flow path 120.

[0014] Then, when the valve element 411 abuts against the valve seat 160, the movable shaft 61 can no longer move upward in the figure. Therefore, when the diaphragm 320 continues to displace upward in the figure, the steel ball 340 moves upward in the figure in accordance with the displacement of the diaphragm 320 and moves away from the valve seat surface 412 of the movable shaft 61. This opens the exhaust valve 270. Then, the control fluid in the secondary side flow path 120 is exhausted from the exhaust port 150 via the feedback chamber 130 and the hollow hole 610. This reduces the control pressure.

[0015] As described above, electropneumatic regulator 100 can continuously control the pressure of the fluid on the secondary side by opening and closing intake valve 260 and exhaust valve 270 relative to each other in response to the displacement of diaphragm 320. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] Japanese Patent Publication No. 2021-170219 Summary of the Invention [Problem to be solved by the invention]

[0017] The electropneumatic regulator 100 according to the prior art has the following problems.

[0018] To change air intake valve 260 from an open state to a closed state, movable shaft 61 must be pushed upward in the figure by the spring force of compression spring 230 and the elastic force of bottom rubber 220. However, since the time it takes for bottom rubber 220, which is crushed when air intake valve 260 is in the open state, to recover to its original shape is longer than that of a spring or the like, there is a risk of a delay in moving movable shaft 61 upward in the figure.

[0019] Furthermore, the bottom rubber 220 may be warped inward when crushed. If the bottom rubber 220 is warped inward, the bottom rubber 220 and the movable shaft 61 interfere with each other, preventing smooth up and down movement of the movable shaft 61 (i.e., reduced sliding properties). Such reduced sliding properties also cause a delay in the upward movement of the movable shaft 61 in the figure.

[0020] A delay in the upward movement of the movable shaft 61 in the figure (i.e., a delay in the closing operation of the air intake valve 260) leads to a delay in the opening operation of the exhaust valve 270, which may make it impossible to reduce the control pressure to the set control pressure. Such a decrease in the accuracy of the control pressure means a decrease in the accuracy of the pressing force that presses the wafer against the polishing pad in the CMP apparatus. Therefore, as semiconductors become increasingly miniaturized and stacked, there is a demand for a pressure control valve that can control the control pressure with higher precision.

[0021] The present invention has been made in view of the above problems, and has an object to provide a pressure control valve that can control the control pressure with higher accuracy. [Means for solving the problem]

[0022] In order to solve the above problems, a pressure control valve according to one aspect of the present invention has the following configuration.

[0023] (1) A pressure control valve comprising an upstream primary flow path, a downstream secondary flow path, an intake valve section for supplying control fluid from the primary flow path to the secondary flow path, an exhaust valve section for discharging the control fluid from the secondary flow path, and a pilot chamber into which pilot fluid for driving the intake valve section and the exhaust valve section is supplied and discharged, characterized in that the intake valve section and the exhaust valve section are located on opposite sides of the primary flow path, the exhaust valve section has an exhaust chamber communicating with the outside of the pressure control valve for performing the exhaust, and the exhaust chamber is located on the opposite side of the exhaust valve section from the intake valve section side.

[0024] (2) In the pressure control valve described in (1), it is preferable that the pilot chamber is located adjacent to the exhaust chamber on the side opposite to the intake valve section of the exhaust valve section, and that a first diaphragm member is provided to separate the exhaust chamber from the pilot chamber, and that the exhaust valve section is provided with an exhaust valve chamber adjacent to the exhaust chamber on the side opposite to the pilot chamber, an exhaust valve body housed in the exhaust valve chamber, a second diaphragm member located opposite to the first diaphragm member and separating the exhaust chamber from the exhaust valve chamber, and a connecting member connecting the first diaphragm member and the second diaphragm member inside the exhaust chamber, and that the connecting member is provided with an exhaust valve hole communicating the exhaust chamber with the exhaust valve chamber, and an exhaust valve seat surrounding the exhaust valve hole and abutting and separating from the exhaust valve body.

[0025] (3) In the pressure control valve described in (2), it is preferable that the intake valve section comprises an intake valve chamber communicating with the exhaust valve chamber, an intake valve hole opening in the same direction as the exhaust valve hole and communicating the primary side flow path with the intake valve chamber, an intake valve seat surrounding the intake valve hole, and an intake valve body abutting and moving away from the intake valve seat, a connecting rod bridging the intake valve chamber and the exhaust valve chamber and connecting the exhaust valve body and the intake valve body, and a guide section against which the connecting rod slides to guide the operation of the exhaust valve body and the intake valve body.

[0026] (4) In the pressure control valve described in (2) or (3), it is preferable that the exhaust valve body has a contact portion that contacts and moves away from the exhaust valve seat and has a spherical shape.

[0027] In the prior art electropneumatic regulator 100, the flow path for exhaust from the exhaust valve 270 (i.e., the hollow hole 610 communicating with the exhaust port 150) passes through the intake valve 260, requiring a bottom rubber 220 for sealing. This can cause a delay in the operation of the intake valve 260. On the other hand, the pressure control valve according to the present invention is characterized in that the exhaust chamber is located on the opposite side of the exhaust valve from the intake valve, eliminating the need for a flow path for exhaust from the exhaust valve that passes through the intake valve. This eliminates the need for the bottom rubber 220 that caused a delay in the operation of the intake valve 260, thereby eliminating the delay in the operation of the intake valve, and ultimately enabling more accurate control of the control pressure. [Effects of the Invention]

[0028] According to the pressure control valve of the present invention, it is possible to control the control pressure with higher accuracy. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 2 is a block diagram showing the configuration of an electropneumatic regulator according to the present embodiment. [Figure 2] 4 is a cross-sectional view of a booster constituting the electropneumatic regulator according to the present embodiment, showing a state in which a valve portion is in a neutral state. FIG. [Figure 3] 4 is a cross-sectional view of a booster that constitutes the electropneumatic regulator according to the present embodiment, showing a state in which an intake valve is open. FIG. [Figure 4] 4 is a cross-sectional view of a booster that constitutes the electropneumatic regulator according to the present embodiment, showing a state in which an exhaust valve is open. FIG. [Figure 5] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 6] 3 is a cross-sectional view of FIG. 2 taken along line B-B. [Figure 7] Graph (A) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to conventional technology at an operating frequency of 1 Hz, and graph (B) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to this embodiment at an operating frequency of 1 Hz. [Figure 8] Graph (A) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to conventional technology at an operating frequency of 5 Hz, and graph (B) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to this embodiment at an operating frequency of 5 Hz. [Figure 9] Graph (A) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to conventional technology at an operating frequency of 10 Hz, and graph (B) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to this embodiment at an operating frequency of 10 Hz. [Figure 10] Graph (A) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to conventional technology at an operating frequency of 15 Hz, and graph (B) is a graph showing the relationship between input pressure and control pressure for an electro-pneumatic regulator according to this embodiment at an operating frequency of 15 Hz. [Figure 11] FIG. 1 is a cross-sectional view of an electropneumatic regulator according to a conventional technique. DETAILED DESCRIPTION OF THE INVENTION

[0030] An embodiment of a pressure control valve according to the present invention will be described in detail with reference to FIGS. 1 to 6. FIG. 1 is a block diagram showing the configuration of an electropneumatic regulator 1 (an example of a pressure control valve) according to this embodiment. FIG. 2 is a cross-sectional view of a booster 20 constituting the electropneumatic regulator 1 according to this embodiment, showing a state in which the valve unit 40 is in a neutral state. FIG. 3 is a cross-sectional view of the booster 20 constituting the electropneumatic regulator 1 according to this embodiment, showing a state in which the intake valve 26 is open. FIG. 4 is a cross-sectional view of the booster 20 constituting the electropneumatic regulator 1 according to this embodiment, showing a state in which the exhaust valve 27 is open. FIG. 5 is a cross-sectional view taken along line AA in FIG. 2. FIG. 6 is a cross-sectional view taken along line BB in FIG. 2. Note that the drawings used in the description are simplified for the purpose of explanation and do not accurately represent the shape, dimensions, etc.

[0031] The electropneumatic regulator 1 is a pressure control valve used, for example, in a CMP apparatus for polishing the surface of a wafer to adjust the pressure that presses the wafer against a polishing pad. As shown in FIG. 1, the electropneumatic regulator 1 includes a booster 20 and a pilot control unit 30.

[0032] The booster 20 includes a valve unit 40, a primary flow path 11, and a secondary flow path 12. The primary flow path 11 and the secondary flow path 12 are connected to the valve unit 40. The primary flow path 11 is connected to a supply source (not shown) of a control fluid (e.g., air) and supplies the control fluid to the valve unit 40. The valve unit 40 includes an inlet valve 26 and an exhaust valve 27 (see FIG. 2 ), which will be described later. The valve unit 40 supplies air to or exhausts air from the secondary flow path 12 in response to the operation of the inlet valve 26 and the exhaust valve 27, thereby adjusting the pressure (control pressure) of the control fluid output from the secondary flow path 12. By adjusting this control pressure, the pressing force that presses the wafer against the polishing pad in the CMP apparatus is adjusted, as described above.

[0033] The pilot control unit 30 includes a connector 3 , an air intake solenoid valve 36 , an exhaust solenoid valve 37 , a control board 38 , and a pressure sensor 39 .

[0034] The connector 3 electrically connects the control board 38 and a host controller (not shown) so as to enable transmission and reception of electrical signals. Although two connectors 3 are shown in Fig. 1, a single connector may be used for both input and output of electrical signals.

[0035] The air supply solenoid valve 36 is a solenoid valve that operates in response to a pulse signal P1 output from a control board 38, and supplies a fluid supplied through a pilot flow path 42 branching from the primary flow path 11 as pilot air to a pilot chamber 35 (described later) via an internal flow path 43. The exhaust solenoid valve 37 is a solenoid valve that operates in response to a pulse signal P2 output from the control board 38, and exhausts pilot air from the pilot chamber 35 (described later) via the internal flow path 43. An exhaust flow path 41 is connected to the exhaust solenoid valve 37, and the pilot air exhausted from the pilot chamber 35 is released to the atmosphere from the exhaust flow path 41. The pressure sensor 39 measures the pressure in the secondary flow path 12 (i.e., the control pressure).

[0036] The control board 38 includes a comparison unit 51 and a control circuit 52. The control circuit 52 is a well-known microcomputer that includes a CPU and memory. A control program for controlling the operation of the electro-pneumatic regulator 1 is stored in the memory. Based on the control program, the comparison unit 51 determines the difference between the set control pressure received from the upper controller and the control pressure measured by the pressure sensor 39. Note that instead of using a microcomputer as described above, control may also be performed by an analog circuit using an operational amplifier, transistors, etc.

[0037] The control board 38 adjusts the pressure in the pilot chamber 35 by PWM controlling the opening and closing operations of the intake solenoid valve 36 and the exhaust solenoid valve 37 based on the difference between the set control pressure received from the upper controller and the control pressure measured by the pressure sensor 39. This operates the valve section 40 (intake valve 26 and exhaust valve 27) of the booster 20, and the control pressure is controlled to the set control pressure.

[0038] (Booster configuration) The booster 20 is formed by stacking a flow path block 10 and a cover body 9 one above the other (in the vertical direction in FIGS. 2 to 6).

[0039] A recess is formed in the surface of the cover body 9 on the flow path block 10 side (the lower surface in FIG. 2-6) toward the upper surface, and this recess forms a pilot chamber 35.

[0040] The flow path block 10 has a primary flow path 11 and a secondary flow path 12 formed on opposing side surfaces. The primary flow path 11 extends in a direction perpendicular to the sliding direction (hereinafter referred to as the sliding direction (up-down direction in the drawing)) of valve bodies (an intake valve body 211 and an exhaust valve body 212) described below. Furthermore, the primary flow path 11 communicates with a first communication flow path 141 extending along the sliding direction in the center of the flow path block 10, and also communicates with the secondary flow path 12 via an intake valve chamber 261 and an exhaust valve chamber 272 described below and second communication flow paths 142, 142 (see FIG. 6).

[0041] Booster 20 also includes therein an intake valve 26 and an exhaust valve 27. Intake valve 26 and exhaust valve 27 are positioned above and below with primary-side flow path 11 and first communication flow path 141 sandwiched therebetween.

[0042] The intake valve 26 is mainly composed of an intake valve chamber 261 , an intake valve hole 262 , an intake valve seat 263 , an intake valve body 211 , and a compression spring 264 .

[0043] The intake valve chamber 261 is formed on the surface of the flow path block 10 opposite to the cover body. The first communication flow path 141 opens into the intake valve chamber 261, and this opening is an intake valve hole 262. The intake valve seat 263 is provided in a protruding manner surrounding the intake valve hole 262. The intake valve element 211 is housed in the intake valve chamber 261 so as to be able to move up and down, and comes into contact with or separates from the intake valve seat 263.

[0044] The air intake valve chamber 261 is closed by a bottom plug 25 that is screwed onto the surface of the flow path block 10 opposite the cover body. An O-ring 24 is provided on the outer periphery of the bottom plug 25, and this O-ring 24 keeps the air intake valve chamber 261 airtight. A compression spring 264 is compressed between the air intake valve body 211 and the bottom plug 25. As a result, the compression spring 264 constantly applies a biasing force to the air intake valve body 211 in the direction of the air intake valve seat 263.

[0045] The exhaust valve 27 has an exhaust chamber 271, an exhaust valve chamber 272, an exhaust valve body 212, a first diaphragm member 273, a second diaphragm member 274, and a connecting member 28 as main components.

[0046] The exhaust chamber 271 is formed in the surface of the flow path block 10 facing the cover body 9. The exhaust chamber 271 is in communication with the outside of the electropneumatic regulator 1. This allows the control fluid that flows into the exhaust chamber 271 from an exhaust valve chamber 272 (described later) to be exhausted to the outside of the electropneumatic regulator 1. Furthermore, an exhaust valve chamber 272 is formed in the bottom surface of the exhaust chamber 271. The exhaust chamber 271, the exhaust valve chamber 272, the first communication flow path 141, and the intake valve chamber 261 are all cylindrical spaces and are all positioned coaxially.

[0047] An annular groove 275 is provided on the surface of the flow path block 10 facing the cover body 9 so as to surround the exhaust chamber 271. A first diaphragm member 273 is disposed in the groove 275. Furthermore, since the diameter of the exhaust chamber 271 is set larger than the diameter of the exhaust valve chamber 272, a step 278 is provided between the exhaust chamber 271 and the exhaust valve chamber 272. A second diaphragm member 274 is disposed in the step 278 so as to face the first diaphragm member.

[0048] The first diaphragm member 273 and the second diaphragm member 274 have their outer peripheral edges fixed by a fixing member 276. More specifically, the fixing member 276 is formed into a cylindrical body having an outer diameter slightly smaller than the inner diameter of the exhaust chamber 271 and an inner diameter substantially the same as the inner diameter of the exhaust valve chamber 272. Such a fixing member 276 is positioned such that one of its axial ends contacts the surface of the first diaphragm member 273 facing the exhaust chamber 271, and the other end contacts the surface of the second diaphragm member 274 facing the exhaust chamber 271. In this state, the cover body is fastened to the flow path block 10, so that the cover body and the fixing member 276 sandwich and fix the outer peripheral edge of the first diaphragm member 273, and the fixing member 276 and a step portion 278 of the flow path block 10 sandwich and fix the outer peripheral edge of the second diaphragm member 274.

[0049] The first diaphragm member 273, being fixed in the above manner, separates the pilot chamber from the exhaust chamber 271. Furthermore, the second diaphragm member 274, being fixed in the above manner, separates the exhaust chamber 271 from the exhaust valve chamber 272.

[0050] The first diaphragm member 273 and the second diaphragm member 274 are connected at their central portions by a connecting member 28 located inside the exhaust chamber 271.

[0051] The connecting member 28 includes a main body portion 281, a first fixed piece 282, and a second fixed piece 283.

[0052] The main body 281 is formed in a substantially cylindrical shape and is disposed concentrically with the exhaust chamber 271. Of both end surfaces of the main body 281 in the axial direction (the vertical direction in the figure), a female thread portion 281a is drilled on the end surface facing the first diaphragm member 273. The first fixed piece 282 is positioned opposite the main body 281, with the first diaphragm member 273 sandwiched between them, and a male screw 284 inserted through the first fixed piece 282 is screwed into the female thread portion 281a of the main body 281, whereby the main body 281 and the first fixed piece 282 sandwich the center of the first diaphragm member 273.

[0053] Furthermore, of both end surfaces of the main body portion 281 in the axial direction (the vertical direction in the figure), a recess 281b is formed in the end surface facing the second diaphragm member 274. A female screw portion 281d is provided on the inner circumferential surface of the recess 281b at the end on the second diaphragm member 274 side. The second fixed piece 283 is positioned opposite the main body portion 281, with the second diaphragm member 274 sandwiched between them, and is inserted through the second diaphragm member 274 and screwed into the female screw portion 281d. As a result, the main body portion 281 and the second fixed piece 283 sandwich the center of the second diaphragm member 274.

[0054] As described above, first diaphragm member 273 is sandwiched between main body portion 281 and first fixed piece 282, and second diaphragm member 274 is sandwiched between main body portion 281 and second fixed piece 283, thereby connecting first diaphragm member 273 and second diaphragm member 274. Connected in this manner, first diaphragm member 273, second diaphragm member 274, and connecting member 28 can be displaced up and down as a unit in response to the supply or exhaust of pilot air in the pilot chamber. In addition, the outer peripheral edges 281e, 282a of the portion of the main body 281 and the first fixed piece 282 that clamps the first diaphragm member 273, and the outer peripheral edges 281e, 281f of the portion of the main body 281 and the second fixed piece 283 that clamps the second diaphragm member 274 are R-chamfered to prevent the diaphragm members 273, 274 from coming into contact and being damaged when displaced.

[0055] The main body 281 of the connecting member 28 has a communication hole 281c that penetrates between the inner circumferential surface of the recess 281b and the outer circumferential surface of the main body 281. In addition, the second fixed piece 283 has an exhaust valve hole 283a that penetrates along the axis.

[0056] The exhaust valve chamber 272 is in communication with the exhaust chamber 271 via the exhaust valve hole 283a, the recess 281b, and the communication hole 281c. Furthermore, the exhaust chamber 271 is open to the atmosphere via the exhaust flow path 41 (see FIG. 1). Therefore, the control fluid in the secondary flow path 12 and the exhaust valve chamber 272 can be exhausted via the exhaust valve hole 283a, the recess 281b, the communication hole 281c, and the exhaust chamber 271.

[0057] Furthermore, an annular exhaust valve seat 283b is provided on the end face of the second fixed piece 283 on the exhaust valve chamber 272 side so as to surround the exhaust valve hole 283a. Therefore, as the first diaphragm member 273, the second diaphragm member 274, and the connecting member 28 are displaced up and down, the exhaust valve seat 283b comes into contact with or moves away from the exhaust valve element 212. In other words, when the exhaust valve seat 283b comes into contact with the exhaust valve element 212, the exhaust of the control fluid is stopped, and when the exhaust valve seat 283b moves away from the exhaust valve element 212, the exhaust is stopped. In addition, a compression spring 215 is provided between the exhaust valve body 212 and the connecting member 28 (second fixed piece 283), and this compression spring 215 applies an auxiliary biasing force to the connecting member 28 (second fixed piece 283) to move the exhaust valve seat 283b away from the second diaphragm member 274.

[0058] The first communication flow path 141 opens into the bottom 272a of the exhaust valve chamber 272, but the opening 141a is closed by a thin rubber member 279 arranged on the bottom 272a.

[0059] An exhaust valve element 212 is housed in the exhaust valve chamber 272. The exhaust valve element 212 is formed in a substantially disk shape, and of both axial end faces, the face on the thin film member 279 side is in contact with the thin film member 279. In addition, a steel ball 214 is provided in the center of the other face on the exhaust valve seat 283b side. This steel ball 214 is the part that comes into contact with or separates from the exhaust valve seat 283b.

[0060] The exhaust valve element 212 is connected to the air intake valve element 211 by connecting rods 213 (see FIG. 5) that extend across the air intake valve chamber 261 and the exhaust valve chamber 272. Therefore, the air intake valve element 211 and the exhaust valve element 212 move up and down as a unit. The connecting rods 213 are inserted through guide portions 101 provided between the air intake valve chamber 261 and the exhaust valve chamber 272, and the up and down movements of the air intake valve element 211 and the exhaust valve element 212 are guided by the guide portions 101.

[0061] (About operation) Next, the operation of the electropneumatic regulator 1 having the above-described configuration will be described. When the electropneumatic regulator 1 is not energized, i.e., when the electropneumatic regulator 1 is not operating, the valve unit 40 is in a neutral state (the state shown in FIG. 2). In the neutral state, the first diaphragm member 273, the second diaphragm member 274, and the connecting member 28 are not moved up and down by the pilot air, and the intake valve 26 and the exhaust valve 27 are both closed. At this time, the control fluid flowing in from the primary-side flow path 11 presses the intake valve element 211 downward in the figure (in a direction away from the intake valve seat 263) in the first communication flow path 141, and presses the exhaust valve element 212 upward in the figure (in a direction toward the exhaust valve seat 283b) via the thin film member 279. The opening area of ​​the opening 141a and the intake valve hole 262 is approximately the same, that is, the pressure-receiving area of ​​the intake valve body 211 and the exhaust valve body 212 (thin film member 279) is approximately the same, so the force of the control fluid pressing against the intake valve body 211 and the force pressing against the exhaust valve body 212 are balanced.

[0062] The operation when the control pressure (pressure in the exhaust valve chamber 272 (secondary flow path 12)) is increased, that is, when the control pressure (pressure in the exhaust valve chamber 272 (secondary flow path 12)) measured by the pressure sensor 39 is lower than the set control pressure, will be described.

[0063] First, the electropneumatic regulator 1 outputs a pulse signal P1 to the air intake solenoid valve 36 to open and close it. On the other hand, it does not output a pulse signal P2 to the exhaust solenoid valve 37, causing it to close. As a result, the fluid that has flowed from the primary flow path 11 into the pilot flow path 42 is supplied to the pilot chamber 35 via the air intake solenoid valve 36, and the pressure in the pilot chamber 35 increases. When the pressure in the pilot chamber 35 becomes higher than the control pressure in the exhaust valve chamber 272 (secondary flow path 12), the first diaphragm member 273, the second diaphragm member 274, and the connecting member 28 are displaced toward the exhaust valve body 212 (downward in the figure).

[0064] When the connecting member 28 is displaced downward in the figure, the exhaust valve seat 283b is pressed against the exhaust valve element 212 (steel ball 214). As a result, if the exhaust valve 27 was in a closed state, the closed state is maintained, and if the exhaust valve 27 was in an open state, the valve is closed. When the exhaust valve 27 is closed, the steel ball 214 abuts against the exhaust valve seat 283b, so that even if the exhaust valve element 212 is tilted with respect to the sliding direction, the steel ball 214 absorbs the tilt. More specifically, when the steel ball 214 abuts against the exhaust valve seat 283b, the tilt of the exhaust valve element 212 is corrected, and the exhaust valve seat 283b settles into a position in which the entire circumference of the exhaust valve seat 283b is in close contact with the steel ball 214.

[0065] Then, when the force pressing exhaust valve seat 283b against exhaust valve element 212 (steel ball 214) becomes greater than the resultant force of the fluid pressure acting on air intake valve element 211, the spring force of compression spring 264, and the pressure of the control fluid acting on exhaust valve element 212 via thin film member 279, exhaust valve element 212 and air intake valve element 211 move downward (in the direction in which air intake valve element 211 moves away from air intake valve seat 263) according to the amount of displacement of connecting member 28. Then, air intake valve element 211 moves away from air intake valve seat 263, and air intake valve 26 opens (the state shown in FIG. 3).

[0066] When the intake valve 26 is opened, the control fluid supplied to the primary flow path 11 flows into the intake valve chamber 261, and the control fluid that has flowed into the intake valve chamber 261 further flows into the exhaust valve chamber 272 and the secondary flow path 12 via the second communication flow paths 142, 142. This causes the control pressure to increase.

[0067] The operation when the control pressure (pressure in the exhaust valve chamber 272 (secondary flow path 12)) is lowered, that is, when the control pressure (pressure in the exhaust valve chamber 272 (secondary flow path 12)) measured by the pressure sensor 39 is higher than the set control pressure, will be described.

[0068] First, the electropneumatic regulator 1 outputs a pulse signal P2 to the exhaust solenoid valve 37 to open and close it. On the other hand, it does not output a pulse signal P1 to the air supply solenoid valve 36, causing it to close. As a result, the fluid in the pilot chamber 35 is exhausted from the exhaust flow path 41 via the exhaust solenoid valve 37, and the pressure in the pilot chamber 35 decreases. When the pressure in the pilot chamber 35 becomes lower than the control pressure in the exhaust valve chamber 272 (secondary-side flow path 12), the first diaphragm member 273, the second diaphragm member 274, and the connecting member 28 are displaced to the side opposite the exhaust valve body 212 (upward in the figure). As a result, the combined force of the fluid pressure acting on the intake valve body 211, the spring force of the compression spring 264, and the pressure of the control fluid acting on the exhaust valve body 212 via the thin film member 279 causes the exhaust valve body 212 and the intake valve body 211 to move upward in the figure (in the direction in which the intake valve body 211 abuts against the intake valve seat 263) following the connecting member 28.

[0069] Then, the intake valve element 211 abuts against the intake valve seat 263, thereby closing the intake valve 26. When the intake valve element 211 abuts against the intake valve seat 263, the exhaust valve element 212 and the intake valve element 211 cannot move further upward in the figure. When the connecting member 28 continues to displace upward in the figure after the intake valve element 211 abuts against the intake valve seat 263, the connecting member 28 (exhaust valve seat 283b) moves away from the exhaust valve element 212 (steel ball 214), and the exhaust valve 27 opens (the state shown in FIG. 4). As a result, the fluid in the exhaust valve chamber 272 (secondary-side flow path 12) is exhausted from the exhaust flow path 41 via the exhaust chamber 271. Therefore, the control pressure in the exhaust valve chamber 272 (secondary-side flow path 12) decreases.

[0070] (About the experimental results) Here, the results of an experiment comparing the operating state of an electropneumatic regulator 100 according to the prior art with the operating state of the electropneumatic regulator 1 according to this embodiment will be described with reference to FIGS. 7 and 8. FIG. 7(A) is a graph showing the relationship between the input pressure and the control pressure for the electropneumatic regulator 100 according to the prior art at an operating frequency of 1 Hz, and FIG. 7(B) is a graph showing the relationship between the input pressure and the control pressure for the electropneumatic regulator 1 according to this embodiment at an operating frequency of 1 Hz. FIG. 8(A) is a graph showing the relationship between the input pressure and the control pressure for the electropneumatic regulator 100 according to the prior art at an operating frequency of 5 Hz, and FIG. 8(B) is a graph showing the relationship between the input pressure and the control pressure for the electropneumatic regulator 1 according to this embodiment at an operating frequency of 5 Hz. FIG. 9(A) is a graph showing the relationship between the input pressure and the control pressure for the electropneumatic regulator 100 according to the prior art at an operating frequency of 10 Hz, and FIG. 9(B) is a graph showing the relationship between the input pressure and the control pressure for the electropneumatic regulator 1 according to this embodiment at an operating frequency of 10 Hz. Figure 10(A) is a graph showing the relationship between input pressure and control pressure for an electropneumatic regulator 100 according to the prior art at an operating frequency of 15 Hz, and Figure 10(B) is a graph showing the relationship between input pressure and control pressure for an electropneumatic regulator 1 according to this embodiment at an operating frequency of 15 Hz. Note that the "input pressure" in Figures 7-10 refers to the set control pressure that the electropneumatic regulator 1, 100 receives from a higher-level controller.

[0071] First, we will explain the conventional electropneumatic regulator 100. When the electropneumatic regulator 100 operates at an operating frequency of 1 Hz (i.e., when the control pressure is increased and decreased once per second), the difference in amplitude and phase shift between the waveform of the input pressure (set control pressure) and the waveform of the control pressure are small, and the control pressure fluctuates in accordance with the input pressure (set control pressure) (see FIG. 7(A)).

[0072] However, as the operating frequency increases, the control pressure becomes unable to follow the lower limit of the input pressure (set control pressure), and the amplitude of the control pressure waveform becomes smaller than the amplitude of the input pressure (set control pressure) waveform. Furthermore, the phase difference between the input pressure (set control pressure) waveform and the control pressure waveform also increases (see Figures 8(A) and 9(A)).

[0073] At an operating frequency of 15 Hz, the amplitude of the control pressure waveform is reduced to about 50% of the amplitude of the input pressure (set control pressure) waveform, as shown in Figure 10(A). Furthermore, the phase difference between the input pressure (set control pressure) waveform and the control pressure waveform expands to 180 degrees.

[0074] The increase in the difference in amplitude and the phase shift as described above, that is, the decrease in the ability of the control pressure to follow the input pressure (set control pressure), is caused by a delay in the operation of the movable shaft 61. Specifically, this is as follows.

[0075] In order to change the air intake valve 260 from an open state to a closed state, the movable shaft 61 must be pushed upward in the figure by the spring force of the compression spring 230 and the elastic force of the bottom rubber 220. However, since the time it takes for the bottom rubber 220, which is crushed when the air intake valve 260 is in the open state, to recover to its original shape is longer than that of a spring or the like, there is a delay in the movement of the movable shaft 61 upward in Figure 11.

[0076] Furthermore, the bottom rubber 220 may be warped inward when crushed. If the bottom rubber 220 is warped inward, the bottom rubber 220 and the movable shaft 61 interfere with each other, preventing smooth up and down movement of the movable shaft 61 (i.e., reduced sliding properties). Such reduced sliding properties also cause a delay in the upward movement of the movable shaft 61 in the figure.

[0077] The delay in the operation of the movable shaft 61 as described above leads to a decrease in the ability of the control pressure to follow the input pressure (set control pressure), which makes it impossible to control the control pressure with high precision.

[0078] Next, we will explain the electropneumatic regulator 1 according to this embodiment. At operating frequencies of 1 Hz and 5 Hz, the ability of the electropneumatic regulator 1 to follow the input pressure (set control pressure) is similar to that of the electropneumatic regulator 100 according to the prior art (see FIGS. 7(B) and 8(B)).

[0079] On the other hand, at operating frequencies of 10 Hz and 15 Hz, both the phase shift and amplitude difference are smaller than those of the electropneumatic regulator 100 according to the prior art, and the ability of the control pressure to follow the input pressure (set control pressure) is improved (see FIGS. 9(B) and 10(B)). More specifically, at an operating frequency of 15 Hz, the amplitude of the control pressure waveform is approximately 80% of the amplitude of the input pressure (set control pressure) waveform. Furthermore, the phase shift between the input pressure (set control pressure) waveform and the control pressure waveform is approximately 90 degrees, which is approximately half the phase shift in the prior art. As such, the ability of the control pressure to follow the input pressure (set control pressure) is improved, making it possible to control the control pressure with high precision.

[0080] (About the effects) As described above, the electropneumatic regulator 1 according to this embodiment has the following features: (1) A pressure control valve (electropneumatic regulator 1) comprising an upstream primary flow path 11, a downstream secondary flow path 12, an intake valve section (intake valve 26) for supplying control fluid from the primary flow path 11 to the secondary flow path 12, an exhaust valve section (exhaust valve 27) for exhausting the control fluid from the secondary flow path 12, and a pilot chamber 35 into and out of which pilot fluid is supplied and exhausted for driving the intake valve section (intake valve 26) and the exhaust valve section (exhaust valve 27), characterized in that the intake valve section (intake valve 26) and the exhaust valve section (exhaust valve 27) are located on opposite sides of the primary flow path 11, the exhaust valve section (exhaust valve 27) has an exhaust chamber 271 that communicates with the outside of the pressure control valve (electropneumatic regulator 1) for exhausting, and the exhaust chamber 271 is located on the opposite side of the exhaust valve section (exhaust valve 27) from the intake valve section (intake valve 26) side (for example, above in FIG. 2 ).

[0081] (2) In the pressure control valve (electropneumatic regulator 1) described in (1), the pilot chamber 35 is located adjacent to the exhaust chamber 271 on the side opposite to the intake valve section (intake valve 26) of the exhaust valve section (exhaust valve 27), and is provided with a first diaphragm member 273 that separates the exhaust chamber 271 from the pilot chamber 35. The exhaust valve section (exhaust valve 27) is provided with an exhaust valve chamber 272 adjacent to the exhaust chamber 271 on the side opposite to the pilot chamber 35, an exhaust valve element 212 accommodated in the exhaust valve chamber 272, and a first diaphragm member 273. It is preferable that the exhaust valve body 212 is provided with a second diaphragm member 274 positioned opposite the diaphragm member 273 and separating the exhaust chamber 271 and the exhaust valve chamber 272, and a connecting member 28 connecting the first diaphragm member 273 and the second diaphragm member 274 inside the exhaust chamber 271, and that the connecting member 28 is provided with an exhaust valve hole 283a that communicates between the exhaust chamber 271 and the exhaust valve chamber 272, and an exhaust valve seat 283b that is provided surrounding the exhaust valve hole 283a and abuts and is spaced from the exhaust valve body 212.

[0082] (3) In the pressure control valve (electropneumatic regulator 1) described in (2), it is preferable that the air intake valve section (air intake valve 26) comprises an air intake valve chamber 261 communicating with the exhaust valve chamber 272, an air intake valve hole 262 opening in the same direction as the exhaust valve hole 283a and communicating the primary side flow path 11 with the air intake valve chamber 261, an air intake valve seat 263 surrounding the air intake valve hole 262, and an air intake valve body 211 abutting and separating from the air intake valve seat 263, and that connecting rods 213, 213 are provided bridging the air intake valve chamber 261 and the exhaust valve chamber 272 and connecting the exhaust valve body 212 and the air intake valve body 211, and that the connecting rods 213, 213 are in sliding contact with guide sections 101, 101 for guiding the operation of the exhaust valve body and the air intake valve body.

[0083] (4) In the pressure control valve (electropneumatic regulator 1) described in (2) or (3), it is preferable that the exhaust valve body 212 has a contact portion (steel ball 214) that contacts and separates from the exhaust valve seat 283b and has a spherical shape.

[0084] In the prior art electropneumatic regulator 100, the flow path for exhaust from the exhaust valve 270 (i.e., the hollow hole 610 communicating with the exhaust port 150) passes through the intake valve 260, requiring a bottom rubber 220 for sealing. This can cause a delay in the operation of the intake valve 260. On the other hand, the pressure control valve (electropneumatic regulator 1) according to this embodiment is characterized in that the exhaust chamber 271 is located on the opposite side of the exhaust valve section (exhaust valve 27) from the intake valve section (intake valve 26) (e.g., upward in FIG. 2). This eliminates the need for the bottom rubber 220, which was a cause of a delay in the operation of the intake valve 26, thereby eliminating the delay in the operation of the intake valve and ultimately enabling more accurate control of the control pressure.

[0085] It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way. Therefore, the present invention can naturally be improved and modified in various ways without departing from the spirit and scope of the present invention. For example, in the above-described embodiment, the electropneumatic regulator 1 is described as being used in a CMP apparatus, but it may also be used as a pressure control valve in other apparatuses. [Explanation of symbols]

[0086] 1 Electro-pneumatic regulator 11 Primary flow path 12 Secondary flow path 26 Air supply valve 27 Exhaust valve 271 Exhaust chamber

Claims

1. an upstream primary flow path; a downstream secondary flow path; an intake valve portion for supplying a control fluid from the primary flow path to the secondary flow path; an exhaust valve portion for exhausting the control fluid from the secondary side flow path; a pilot chamber into which a pilot fluid for driving the intake valve portion and the exhaust valve portion is supplied and exhausted; A pressure control valve comprising: the intake valve unit and the exhaust valve unit are positioned across the primary-side flow path; the exhaust valve portion includes an exhaust chamber communicating with the outside of the pressure control valve in order to perform the exhaust; the exhaust chamber is located on the opposite side of the exhaust valve portion from the intake valve portion; A pressure control valve characterized by:

2. 2. The pressure control valve according to claim 1, the pilot chamber is located adjacent to the exhaust chamber on the side of the exhaust valve section opposite to the intake valve section; a first diaphragm member that separates the exhaust chamber from the pilot chamber; The exhaust valve portion is an exhaust valve chamber adjacent to the exhaust chamber on the opposite side to the pilot chamber; an exhaust valve body accommodated in the exhaust valve chamber; a second diaphragm member positioned opposite the first diaphragm member and separating the exhaust chamber from the exhaust valve chamber; a connecting member that connects the first diaphragm member and the second diaphragm member inside the exhaust chamber; To have The connecting member is an exhaust valve hole that communicates the exhaust chamber with the exhaust valve chamber; an exhaust valve seat that is provided to surround the exhaust valve hole and that abuts against and separates from the exhaust valve body; To have A pressure control valve characterized by:

3. 3. The pressure control valve according to claim 2, The air intake valve portion is an intake valve chamber communicating with the exhaust valve chamber; an intake valve hole that opens in the same direction as the exhaust valve hole and that connects the primary flow path and the intake valve chest; an intake valve seat provided to surround the intake valve hole; an intake valve body that comes into contact with and separates from the intake valve seat; To have a connecting rod that connects the exhaust valve body and the intake valve body across the intake valve chamber and the exhaust valve chamber; a guide portion with which the connecting rod slides to guide the operation of the exhaust valve body and the intake valve body; A pressure control valve characterized by:

4. 4. The pressure control valve according to claim 2 or 3, the exhaust valve body has a spherical contact portion that contacts and separates from the exhaust valve seat; A pressure control valve characterized by:

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