JP4437744B2 - Liquid supply apparatus, substrate processing apparatus, and liquid supply method - Google Patents

Description

  The present invention relates to a liquid supply apparatus and a liquid supply method for supplying a liquid. Preferably, the liquid supply apparatus is used in a substrate processing apparatus for processing a substrate.

  Conventionally, in the cleaning of a semiconductor substrate (hereinafter simply referred to as “substrate”), dilute hydrochloric acid (HCl) is used as a cleaning liquid instead of pure water, so that fine particles in the cleaning liquid are transferred to the substrate surface by Coulomb force. There is known a technique for preventing adhesion to the surface. Further, the substrate may be etched using dilute hydrofluoric acid (HF), or the substrate may be finally cleaned using a dilute acid solution (hydrochloric acid, hydrofluoric acid, or the like).

  In the substrate cleaning apparatus, a diluted solution obtained by diluting a stock solution of hydrochloric acid to 1/1000 or less is used. Such a diluting solution is usually manufactured by a method (so-called direct mixing method) in which a small amount of hydrochloric acid stock solution is directly injected into a pure water pipe of a cleaning device in order to simplify the apparatus configuration or reduce the size. . In the cleaning device, the flow rate of hydrochloric acid injected into the pure water is measured by a flow meter, and the flow rate of hydrochloric acid is controlled based on the output from the flow meter, so that the dilution liquid has a desired concentration.

  As such a flow meter, for example, Patent Documents 1 and 2 disclose a differential pressure type flow meter that measures a flow rate by measuring a pressure difference before and after a nozzle provided in a flow path. Patent Documents 3 and 4 disclose a differential pressure type flow meter that stably measures a minute flow rate by measuring a pressure difference between both ends of a capillary (capillary tube).

In Patent Document 5, in a flow meter (flow meter) having a float that moves up and down in accordance with the flow rate of a fluid, a rod-like body protruding above and below the float, and a pipeline that surrounds the float and the circumference of the rod-like body A technique for improving the flow rate measurement accuracy by disposing a magnet on the tube and holding the float on the central axis of the pipe to prevent minute vibrations is disclosed. In Patent Document 5, in the substrate processing apparatus to which the flow meter is applied, there is also a technique for adjusting the supply amount of the chemical liquid by controlling an air valve provided in the chemical liquid supply pipe based on an output from the flow meter. It is disclosed.
US Pat. No. 5,672,832 US Pat. No. 6,578,435 JP 2004-226142 A JP 2004-226144 A Japanese Patent Laid-Open No. 11-94608

  By the way, in the manufacture of the diluted solution, it is necessary to inject a very small amount of stock solution with high accuracy. For example, in a batch-type cleaning apparatus, the flow rate of the stock solution is usually 100 ml / min or less, and this minute flow rate must be measured and controlled with high accuracy. In the single wafer cleaning apparatus, the flow rate of the stock solution to be measured is 10 ml / min or less.

  Since the differential pressure type flowmeters of Patent Documents 1 and 2 perform measurement by generating turbulent flow in the vicinity of the nozzle, they are not suitable for measuring a minute flow rate in which there is a high possibility that the flow becomes a laminar flow. On the other hand, some liquid mass flow flowmeters used for measuring minute flow rates are covered with a resin film in order to improve durability against chemicals, but are thick to obtain durability against hydrofluoric acid and the like. A resin film is required, and it is difficult to accurately measure the flow rate.

  In the differential pressure type flowmeters of Patent Documents 3 and 4, a long capillary is used as the pressure loss part, and it is assumed that the liquid flow in the capillary is a laminar flow. Seeking the flow rate. However, when the flow is in the transition zone or is turbulent, the flow rate measurement accuracy is lowered, so it is important to obtain a stable laminar flow. In addition, although a capillary having a bent portion is actually used, the flow rate is obtained using the above-described theoretical formula regarding a straight circular tube, and thus an error in flow rate measurement becomes large.

  In the substrate processing apparatus of Patent Document 5, the flow rate of the chemical solution is adjusted by controlling the air valve provided in the chemical solution supply pipe to change the opening degree of the air valve (that is, the degree of throttling of the supply pipe). Therefore, the chemical solution can be supplied with sufficient accuracy when supplying a large flow rate, but there is a limit to improving the accuracy of the supply amount when supplying a very small flow rate. Furthermore, in the flow path through which high-concentration hydrofluoric acid or hydrochloric acid flows, the liquid contact part of a flow rate adjustment valve such as an air valve is usually formed of fluororesin, but fluororesin generally has higher processing accuracy than metal or the like. It is low and easily deformed by external force and ambient temperature. It is difficult to form a flow rate adjusting valve for adjusting an extremely small cross-sectional area of a fine channel with high accuracy using such a material having low shape stability.

  On the other hand, for example, when an attempt is made to supply a minute flow rate of liquid by pushing out with an air cylinder without using a flow rate adjusting valve such as an air valve, it is necessary to move the piston of the air cylinder at an extremely low speed. In this case, since the sliding resistance between the cylinder and the piston repeatedly fluctuates between static friction and dynamic friction, the piston vibrates or repeatedly moves at a speed higher than a predetermined speed after the piston stops. Phenomena (so-called chattering and shaving) occur and the accuracy of the supply amount decreases. When the air cylinder is driven while preventing such shackles, it is usually said that it is difficult to set the moving speed of the piston to 1 mm / sec or less.

  The present invention has been made in view of the above problems, and an object of the present invention is to supply a minute flow rate of liquid while accurately controlling the flow rate.

The invention according to claim 1 is a liquid supply apparatus for supplying a liquid, wherein a pump mechanism that sends liquid to a flow path by applying pressure to a deformable variable container to reduce its volume, and the pump mechanism A flow meter that is disposed on the downstream side of the liquid and that measures a flow rate per unit time of the liquid flowing through the flow path, and based on the flow rate of the liquid obtained by the flow meter, the liquid flowing through the flow path An electric signal for controlling the pressure applied to the variable container is supplied to the pump mechanism so that the flow rate becomes a preset flow rate set as a flow rate when the liquid is sent to the flow path by compression of the variable container. The flow meter is disposed between the circular pipe, which is a pressure loss part provided as a part of the flow path, and the pump mechanism and the circular pipe, and flows into the circular pipe. The pressure of the liquid A differential pressure type flow meter comprising a first pressure gauge to be measured and a second pressure gauge that is arranged downstream of the circular pipe and that measures the pressure of the liquid flowing out of the circular pipe. While the liquid is being delivered to the flow path by a single compression, the flow rate of the liquid is measured by the flow meter.

  The invention according to claim 2 is the liquid supply apparatus according to claim 1, wherein the variable container is made of resin.

  A third aspect of the present invention is the liquid supply apparatus according to the first or second aspect, wherein the variable container includes a bellows.

  A fourth aspect of the present invention is the liquid supply apparatus according to any one of the first to third aspects, wherein the pump mechanism includes a pressure-resistant container that houses the variable container, the pressure-resistant container, and the variable And an electropneumatic regulator for adjusting the pressure between the container and the container.

  Invention of Claim 5 is the liquid supply apparatus of Claim 1 or 2, Comprising: The said variable container is provided with the bellows, The said pump mechanism accommodates the said variable container inside, The said pressure vessel, An electropneumatic regulator that adjusts the pressure between the pressure vessel and the variable vessel is provided, and one end of the variable vessel is fixed to the pressure vessel and the other end is a free end.

  A sixth aspect of the present invention is the liquid supply apparatus according to the fifth aspect, wherein the pump mechanism further includes a displacement sensor that detects a displacement of the other end with respect to the pressure resistant container.

  A seventh aspect of the present invention is the liquid supply apparatus according to any one of the fourth to sixth aspects, wherein the pump mechanism prevents the liquid from leaking from the variable container at a bottom portion inside the pressure-resistant container. A liquid leakage sensor for detection is further provided.

  The invention according to an eighth aspect is the liquid supply apparatus according to any one of the first to third aspects, wherein the pump mechanism includes a motor whose output torque is controllable and a torque output from the motor. A pressurizing mechanism for applying pressure to the variable container.

  The invention according to claim 9 is the liquid supply apparatus according to any one of claims 1 to 8, further comprising another pump mechanism having the same structure as the pump mechanism, and controlled by the control unit, The compression of one of the variable container of the pump mechanism and the other variable container of the other pump mechanism, and the other extension in parallel with the other, are applied to the variable container and the other variable container. Alternately.

  The invention according to claim 10 is the liquid supply apparatus according to claim 9, wherein the expansion of the other of the variable container and the other variable container is stopped before the compression of one of the variable container and the other variable container is stopped. Then, the other compression is started.

An eleventh aspect of the present invention is the liquid supply apparatus according to any one of the first to tenth aspects, wherein the liquid flow having a Reynolds number of 2000 or less is formed in the circular pipe of the flow meter. The

  A twelfth aspect of the present invention is the liquid supply apparatus according to the eleventh aspect, wherein the circular tube is made of resin.

  The invention according to claim 13 is a substrate processing apparatus for processing a substrate, wherein a first flow path through which the first liquid flows, and a second flow path through which the second liquid flows and merges with the first flow path, The liquid supply device according to any one of claims 1 to 12, wherein the second liquid is supplied while being provided upstream of the second flow path, and the merging of the first flow path and the second flow path. A processing tank is provided on the downstream side of the point and stores a processing liquid that is a mixed liquid of the first liquid and the second liquid and in which the substrate is immersed.

  The invention described in claim 14 is a substrate processing apparatus for processing a substrate, wherein the substrate holding unit that holds the substrate, the first flow path through which the first liquid flows, the second liquid flows, and the first flow A liquid supply device according to any one of claims 1 to 12, wherein the second liquid is supplied while being provided upstream of the second flow path and the second flow path that merges with the path, and the first flow path. And a processing liquid supply unit that is located downstream of the confluence of the first flow path and the second flow path and supplies a processing liquid that is a mixed liquid of the first liquid and the second liquid to the substrate.

The invention according to claim 15 is a liquid supply method for supplying a liquid, wherein a) a deformable variable container is expanded in a pump mechanism to increase its volume, and liquid from a liquid supply source is supplied to the variable container. A step of storing, and b) a step of sending the liquid to the flow path by reducing the volume by applying pressure to the variable container, wherein the step b) is disposed downstream of the pump mechanism. Measuring the flow rate per unit time of the liquid flowing through the flow path with the flow meter, and b2) based on the flow rate measured in the b1) step, the flow rate of the liquid flowing through the flow path is : A step of controlling the pressure applied to the variable container so as to be a preset flow rate set as a flow rate when the liquid is sent to the flow path by compression of the variable container, and the flow meter comprises: Said A circular tube is a pressure loss portion provided as part of the road, a first pressure meter for measuring the pressure of the liquid flowing into the circular pipe is disposed between the pump mechanism and the circular tube, the A differential pressure type flow meter disposed downstream of the circular pipe and measuring a pressure of the liquid flowing out of the circular pipe, and is supplied to the flow path by one compression of the variable container. While the liquid is being delivered, the flow rate of the liquid is measured by the flow meter.

The invention described in claim 16 is the liquid supply method according to claim 15, wherein c) another variable container that can be deformed in another pump mechanism is extended to increase the volume, and the liquid supply Storing the liquid from a source in the other variable container; and d) delivering the liquid to the flow path by reducing the volume by applying pressure to the other variable container. In the d1 step, d1) a step of measuring the flow rate per unit time of the liquid flowing through the flow path by the flowmeter on the downstream side of the another pump mechanism, and d2) the d1) step based on the measured flow rate, the flow rate of the liquid flowing through the passage and a step of controlling the pressure applied to said another variable container so that the set flow rate, is carried out concurrent wherein a) Engineering And said step d), the said b) step and the step c) is carried out concurrent, are alternately performed.

  The invention according to claim 17 is the liquid supply method according to claim 16, wherein the constant time after the start of the step b) and the constant time before the end of the step b) It overlaps with a certain time before the end and a certain time after the start of the step d).

  In the present invention, it is possible to supply a liquid having a minute flow rate while accurately controlling the flow rate. In the inventions of claims 2 and 12, various kinds of liquid can be supplied.

  In the invention of claim 3, the volume of the variable container can be easily changed and the deterioration of the variable container can be suppressed. In the invention of claim 4, the pressure between the pressure vessel and the variable vessel can be controlled with high responsiveness and high accuracy. In the invention of claim 5, the flow rate of the supplied liquid can be controlled with higher accuracy.

  In the inventions of claims 6 and 7, the reliability of the operation of the apparatus can be improved. In the invention of claim 8, the configuration of the apparatus can be simplified.

  According to the ninth and sixteenth aspects of the present invention, a minute flow rate of liquid can be continuously supplied over a long period of time while accurately controlling the flow rate. According to the tenth and seventeenth aspects of the present invention, the flow rate fluctuation that occurs when the compression of the two variable containers is switched can be easily suppressed by the pressure control.

  In the invention of claim 11, the flow rate can be stably measured with high accuracy.

  In the inventions according to claims 13 and 14, the substrate can be processed with the processing liquid in which the second liquid is mixed at a desired concentration.

  FIG. 1 is a diagram showing a configuration of a liquid supply apparatus 1 according to the first embodiment of the present invention. The liquid supply apparatus 1 includes a flow path 11 through which liquid flows, a liquid supply source 12 that is connected to the upstream side of the flow path 11 and stores liquid, and is disposed on the downstream side of the liquid supply source 12. A pump mechanism 13 that stores liquid and delivers liquid to the downstream side of the flow path 11, a differential pressure type flow meter that is disposed on the downstream side of the pump mechanism 13 and measures the flow rate per unit time of the liquid flowing through the flow path 11 14 and a control unit 15 for controlling these mechanisms. On the flow path 11, a first filter 111 and a first check valve 112 are provided between the liquid supply source 12 and the pump mechanism 13, and a second check valve 113 is provided between the pump mechanism 13 and the flow meter 14. Further, a pressure adjusting tube 147 and a second filter 114 are provided downstream of the flow meter 14. In FIG. 1, the parallel oblique lines in the cross section are omitted.

  The liquid supply source 12 is a bottle whose liquid contact portion is covered with a fluororesin (for example, PTFE (polytetrafluoroethylene)), and is open to the atmosphere. Stock solutions such as hydrochloric acid and hydrofluoric acid are stored in the liquid supply source 12, and these stock solutions are supplied to the pump mechanism 13 via the flow path 11. The first filter 111 is formed of, for example, PTFE, and impurities such as particles are removed from the liquid supplied to the pump mechanism 13 by the first filter 111. Similarly, the second filter 114 is made of a fluororesin such as PTFE and has, for example, a 0.05 μm mesh. In the liquid supply device 1, impurities are removed from the liquid supplied from the liquid supply device 1 to other devices by the second filter 114.

  The first check valve 112 and the second check valve 113 are, for example, entirely made of PFA (perfluoroalkyl vinyl ether) and prevent the liquid from flowing backward from the downstream side to the upstream side of each check valve. The first check valve 112 and the second check valve 113 may have a structure in which a sapphire ball and a sapphire valve seat are provided in an outer cylindrical portion made of a fluororesin.

  The liquid contact portion of the liquid supply source 12, the first filter 111 and the second filter 114, and the first check valve 112 and the second check valve 113 are made of fluororesin or the like. On the other hand, it has high durability (mainly corrosion resistance). The pressure adjusting tube 147 will be described later together with the detailed description of the flow meter 14.

  The pump mechanism 13 includes a deformable resin variable container 131, a substantially cylindrical pressure-resistant container 132 that accommodates the substantially cylindrical variable container 131 therein, and air is supplied to or discharged from the pressure-resistant container 132. An electropneumatic regulator 133 and an ejector 134 that adjust the pressure between the container 132 and the variable container 131 are provided. The variable container 131 is connected to the flow path 11 between the first check valve 112 and the second check valve 113. In addition, the electropneumatic regulator 133 and the ejector 134 are connected to the pressure vessel 132 via air valves 1331 and 1341, respectively.

  The variable container 131 includes a bellows 1311 as a part thereof. The material of the variable container 131 includes PTFE, PFA, PEEK (polyether ether ketone), PCTFE (polychlorotrifluoroethylene), ETFE (ethylene tetrafluoroethylene), FEP (fluorinated ethylene propylene), and the like. The material of the variable container 131 is determined based on the type of liquid. In the present embodiment, the variable container 131 is formed of a fluororesin such as PFA. Since the pressure resistant container 132 does not normally come into contact with the liquid stored in the variable container 131, the pressure resistant container 132 may be formed of vinyl chloride or the like having a slightly lower durability against the liquid than the variable container 131.

  The electropneumatic regulator 133 is connected to an external compressed air supply source, an air inlet for pressurization, an outlet for pressure release, and an inside of the pressure vessel 132 and is variable from the pressure vessel 132. It has an output port for adjusting the pressure between the container 131 and matches the instructed pressure based on an electric signal given from the feedback controller 151 of the control unit 15 (for example, in proportion to the input current or the like). Thus, the pressure between the pressure vessel 132 and the variable vessel 131 is continuously and continuously controlled. When the pressure in the pressure vessel 132 is controlled by the electropneumatic regulator 133, the air valve 1331 is opened by the electromagnetic valve 1332 driven by the sequence controller 152 of the control unit 15.

  The ejector 134 is connected to an external compressed air supply source via a regulator 1343 and an air valve 1344. When the air in the pressure vessel 132 is discharged by the ejector 134, the ejector 134 is driven by the sequence controller 152. The air valves 1341 and 1344 are opened by the valves 1342 and 1345, and the air from the compressed air supply source flows out of the ejector 134 at a high speed, whereby the air in the pressure-resistant container 132 is discharged through the ejector 134. In the pump mechanism 13, electromagnetic valves may be used instead of the air valves 1331, 1341, 1344.

  2 and 3 are enlarged views showing the vicinity of the variable container 131 and the pressure container 132 of the pump mechanism 13. 2 and 3 show the variable container 131 in an expanded and compressed state, respectively. In the pump mechanism 13, the upper end portion 1312 of the variable container 131 having the bellows 1311 is fixed to the pressure resistant container 132, and the lower end portion 1313 is a free end.

  In the pump mechanism 13, the electropneumatic regulator 133 (see FIG. 1) supplies air from the bottom of the pressure-resistant container 132 (that is, the portion facing the lower end 1313 of the variable container 131) into the pressure-resistant container 132 and is variable. By applying pressure to the container 131, the variable container 131 is compressed from the state shown in FIG. 2 (hereinafter referred to as “extended state”) to the state shown in FIG. 3 (hereinafter referred to as “compressed state”). Deforms gradually. In this way, by applying pressure to the variable container 131 to reduce the volume, the liquid in the variable container 131 is sent to the flow path 11. The liquid delivered from the variable container 131 is prevented from flowing to the liquid supply source 12 side (that is, the upstream side) by the check valve 112, and flows to the flow meter 14 side (that is, the downstream side) via the check valve 113. Flowing.

  In the pump mechanism 13, the ejector 134 (see FIG. 1) discharges air in the pressure vessel 132 from the bottom of the pressure vessel 132, and the pressure vessel 132 is decompressed to a negative pressure, whereby the variable vessel 131. Gradually deforms from the compressed state shown in FIG. 3 to the expanded state shown in FIG. Thus, by expanding the variable container 131 to increase the volume, the liquid is sucked from the liquid supply source 12 via the flow path 11 and the check valve 112 and flows into the variable container 131, and is stored in the variable container 131. Is done. At this time, the check valve 113 prevents the liquid from being sucked from the downstream side of the pump mechanism 13.

  In the pump mechanism 13, the volume of the space between the variable container 131 and the pressure-resistant container 132, that is, the space subject to pressure control by the electropneumatic regulator 133 is reduced, so that the liquid supply source 12 changes to the variable container 131. It is possible to enhance the responsiveness of the suction of the liquid and the delivery of the liquid from the variable container 131.

  As shown in FIGS. 2 and 3, the pump mechanism 13 includes a displacement sensor 135 that detects the displacement of the lower end portion 1313 that is a free end of the variable container 131 with respect to the pressure resistant container 132, and the liquid from the variable container 131 should be A liquid leakage sensor 136 is provided to detect this when there is leakage.

  The displacement sensor 135 includes a light emitting unit 1351 and a light receiving unit which are opposed to each other with the variable container 131 in an expanded state shown in FIG. Two sets of 1352 are provided. As for the attachment position of the light emitting part 1351 and the light receiving part 1352 in the extension and compression directions of the bellows 1311, one set is substantially the same as the lower end part 1313 of the variable container 131 in the extended state, and the other set is shown in FIG. The pressure container 132 is slightly below the bottom end 1313 of the variable container 131 in the compressed state.

  In the pump mechanism 13, when the variable container 131 is in the extended state as shown in FIG. 2, the light from the two light emitting portions 1351 is blocked by the variable container 131, and the variable container 131 is in the extended state by the displacement sensor 135. It is judged. Further, as shown in FIG. 3, when the variable container 131 is in a compressed state, light from the two light emitting units 1351 passes through the inside of the pressure-resistant container 132 and is received by the light receiving unit 1352, and the variable sensor 131 receives the variable container 131. It is determined that 131 is in a compressed state. When the light from the light emitting unit 1351 on the bottom side of the pressure vessel 132 is received by the opposing light receiving unit 1352 and the light from the other light emitting unit 1351 does not reach the light receiving unit 1352, the displacement sensor 135 can change the variable container. It is determined that the state 131 is intermediate between the states shown in FIGS.

  The leak sensor 136 includes a pair of electrodes 1361, and the pair of electrodes 1361 is disposed at the bottom of a groove 1321 provided at the bottom inside the pressure vessel 132. In the pump mechanism 13, when liquid leaks from the variable container 131, the leaked liquid accumulates in the groove 1321 at the bottom of the pressure-resistant container 132, and the pair of electrodes 1361 are electrically connected to each other via the liquid (electrolyte) in the groove 1321. Connected. Then, the leakage of the liquid from the variable container 131 is detected by detecting the continuity between the pair of electrodes 1361 by the liquid leakage sensor 136.

  4 and 5 are a front view and a plan view showing the configuration of the flow meter 14, respectively. As shown in FIGS. 4 and 5, the flow meter 14 includes a tubular pressure loss tube 143 that is a pressure loss portion provided as a part of the flow path 11 (see FIG. 1), and a tube base 144 to which the pressure loss tube 143 is attached. The first pressure gauge 141 that is disposed between the pump mechanism 13 (see FIG. 1) and the pressure loss tube 143 (left side in FIGS. 4 and 5) and measures the pressure of the liquid flowing into the pressure loss tube 143, the pressure loss tube 2 is provided with a second pressure gauge 142 that measures the pressure of the liquid flowing out from the pressure drop tube 143, and further, as shown in FIG. 4, a storage unit 145 that stores information, and various calculations The calculating part 146 which performs is provided.

  The pressure loss tube 143 is made of resin and has high durability (mainly corrosion resistance) against various kinds of liquids. Further, the pressure loss tube 143 has flexibility, and is shaped in a coil shape on the upper side of the tube base 144 as shown in FIG. The material of the pressure loss tube 143 includes PEEK, PTFE, PCTFE, PFA, ETFE, FEP, and the like. The material of the pressure loss tube 143 is determined based on the type of liquid to be measured, the inner diameter of the pressure loss tube 143, and the like. In the present embodiment, the pressure loss tube 143 is made of PFA.

  The inner diameter of the pressure drop tube 143 is determined based on the upper limit value of the flow rate measured by the flow meter 14 so that the Reynolds number of the liquid flow in the pressure drop tube 143 is 2000 or less. The Reynolds number is a dimensionless number representing the nature of the flow (i.e., whether the flow is laminar or turbulent). When the Reynolds number is smaller than the critical Reynolds number (about 2000 to 2300), the flow is laminar. It becomes a flow. The Reynolds number Re of the tubular pressure loss tube 143 is expressed by the following equation 1 where the inner diameter of the pressure loss tube 143 is D (m).

Here, ρ and μ indicate the density (kg / m ³ ) and viscosity coefficient (N · s / m ² ) of the liquid flowing in the pressure drop tube 143, and U is the liquid in a cross section perpendicular to the longitudinal direction of the pressure drop tube 143. Mean flow velocity (m / s), Q represents the flow rate of liquid (m ³ / s).

  In the flow meter 14, the maximum value of the Reynolds number within the measurement range (that is, the Reynolds number at the upper limit of the measurement flow rate) is 2000 or less, and a laminar flow is formed in the pressure loss tube 143. Therefore, the run-up distance X (m) required until the liquid flow sufficiently develops (that is, the flow velocity distribution in the cross section of the pressure loss tube 143 is stabilized) is the Reynolds number Re and the inner diameter of the pressure loss tube 143. Using D (m), it is expressed as Equation 2 as a theoretical formula of Bousinesque.

  The length of the pressure loss tube 143 is preferably set to be 130 times or more of the inner diameter so as to be longer than the run-up distance even when the Reynolds number is 2000. The length of the pressure loss tube 143 is determined by the magnitude of the pressure loss required in the pressure loss tube 143 (that is, the differential pressure at both ends of the pressure loss tube 143), and the outer diameter of the pressure loss tube 143 is the pressure loss made of resin. In order to ensure the mechanical strength of the tube 143, the inner diameter is 1.5 times or more.

  The tube base 144 is a block made of resin (for example, made of PTFE, which is a fluororesin), and has L-shaped and inverted L-shaped flow paths inside. As shown in FIG. 4, both ends of the pressure drop tube 143 are detachably attached to the upper surface of the tube base 144 through a resin tube fitting. As the tube fitting, various small diameter fittings used for liquid chromatography and the like can be used. The flow path inside the tube base 144, the pressure drop tube 143, the flow paths inside the first pressure gauge 141 and the second pressure gauge 142, which will be described later, and the pressure receiving chambers 1411 and 1421 are provided in the flow path 11 of the liquid supply apparatus 1. There are also some.

  As shown in FIGS. 4 and 5, the first pressure gauge 141 and the second pressure gauge 142 have a substantially cylindrical shape that is easy to vent when liquid is injected because of its low height (so-called air bleedability is good). 4 and the wetted parts 1412 and 1422 provided in the pressure receiving chambers 1411 and 1421 are made of resin (for example, made of PTFE which is a fluororesin). In the first pressure gauge 141 and the second pressure gauge 142, the internal flow path and the pressure receiving chambers 1411 and 1421 are connected without branching, so that liquid retention is prevented. In addition, both ends of the flow paths inside the first pressure gauge 141 and the second pressure gauge 142 have a joint structure that can be easily connected. In the present embodiment, the measurement range of the first pressure gauge 141 and the second pressure gauge 142 is 0 to 0.2 MPa (megapascal).

  In the flow meter 14, the liquid that continuously flows into the first pressure gauge 141 from the upstream side sequentially passes through the first pressure gauge 141, the tube base 144, the pressure loss tube 143, and the second pressure gauge 142, and flows downstream. Spill into. Then, while the liquid continues to flow in the flow meter 14, the flow rate of the liquid is continuously measured. Hereinafter, the flow of liquid flow measurement by the flow meter 14 will be described.

  In the flow meter 14, while the liquid continues to flow, the pressure of the liquid flowing into the pressure drop tube 143 is measured by the first pressure gauge 141, and the pressure of the liquid flowing out of the pressure drop tube 143 is measured by the second pressure gauge 142. The Then, outputs from the first pressure gauge 141 and the second pressure gauge 142 (for example, a pressure measurement value taken as an electric signal of 4 to 20 mA (milliampere) by both pressure gauges) are supplied to a subtracter 1461 of the calculation unit 146. Then, the subtracter 1461 subtracts the output of the second pressure gauge 142 from the output of the first pressure gauge 141 to obtain the differential pressure at both ends of the pressure loss tube 143.

  FIG. 6 is a diagram showing the relationship between the differential pressure at both ends of the pressure loss tube 143 and the flow rate of the liquid flowing through the pressure loss tube 143 (hereinafter referred to as “flow rate information”). As shown in FIG. 6, in the flow meter 14, the differential pressure and the flow rate are in a substantially proportional relationship. Since the flow in the pressure loss tube 143 is a laminar flow having a Reynolds number of 2000 or less, the differential pressure and the flow rate should theoretically be directly proportional, but the reason for not being completely proportional is the vicinity of both ends of the pressure loss tube 143 This is considered to be due to the influence of the flow and the surface condition of the inner surface of the pressure loss tube 143.

  The flow rate information is obtained in advance by the following method before the flow meter 14 is attached to the liquid supply apparatus 1. First, a syringe pump is attached to the upstream side of the first pressure gauge 141, and a liquid (preferably pure water) is injected at a constant discharge amount. The injected liquid flows out through the first pressure gauge 141, the tube base 144 and the pressure drop tube 143, and the second pressure gauge 142, and the first pressure gauge 141 and the second pressure gauge 142 pass the liquid. The pressure at that time is measured to determine the differential pressure. Then, after a predetermined time has elapsed, the weight of the liquid flowing out of the flow meter 14 is measured, and a flow rate corresponding to the differential pressure is obtained. Thereafter, the flow rate information shown in FIG. 6 is obtained by changing the discharge amount of the syringe pump and repeating the measurement of the differential pressure and the flow rate. The flow rate information obtained in this way is stored in the storage unit 145 before the flow meter 14 is actually used.

  In the flow meter 14 shown in FIG. 4, the differential pressure at both ends of the pressure loss tube 143 obtained by the subtractor 1461 is sent to the linearizer 1462 as an electric signal of 0 to 5 V, for example, and stored in the storage unit 145 in advance. The flow rate information is read by the linearizer 1462. In the linearizer 1462, the flow rate per unit time of the liquid flowing through the pressure drop tube 143 is automatically obtained based on the differential pressure and flow rate information. The flow rate information stored in the storage unit 145 may be, for example, a table format or an approximate expression.

  As shown in FIG. 1, the aforementioned pressure adjusting tube 147 is provided between the flow meter 14 and the second filter 114. Similar to the pressure drop tube 143, the pressure adjusting tube 147 is made of a resin having high durability against various types of liquids, has flexibility, and is shaped into a coil shape.

  In the liquid supply device 1, the liquid flowing out of the flow meter 14 is relatively lowered by passing through the pressure adjusting tube 147 before being supplied to another device or the like via the second filter 114. I am letting. For this reason, in the second pressure gauge 142 of the flow meter 14, even when the supply pressure required for the liquid supplied from the liquid supply apparatus 1 is substantially equal to the atmospheric pressure (that is, close to atmospheric release). It is possible to avoid the measurement pressure (that is, the differential pressure from the atmospheric pressure) from being near zero where the measurement accuracy is low. As a result, the measurement accuracy of the flow rate in the flow meter 14 can be improved. From the viewpoint of improving the measurement accuracy of the flow rate, the length of the pressure adjusting tube 147 is set such that, for example, the minimum value of the pressure measured by the second pressure gauge 142 is 10 from the lower limit side of the measurement range of the second pressure gauge 142. % Is preferably determined to be in the range of 20% or more (in this embodiment, 20 kPa or more).

  Next, the flow of liquid supply by the liquid supply apparatus 1 will be described with reference to FIG. When the liquid is supplied by the liquid supply device 1, first, as a preparatory work, a liquid filling operation to the pump mechanism 13 and the flow path 11 is performed by an operator's operation. During the filling operation, the downstream end of the flow path 11 is connected to the drain.

  1, the air valve 1331 of the pump mechanism 13 is closed and the air valves 1341 and 1344 are opened by the sequence controller 152 of the control unit 15 shown in FIG. Is discharged by the ejector 134 and pressure reduction in the pressure vessel 132 is started. As a result, the variable container 131 that has been in a compressed state (see FIG. 3) is expanded, the liquid is sucked from the liquid supply source 12, supplied to the variable container 131, and stored in the variable container 131. When it is detected by the displacement sensor 135 (see FIG. 2) that the variable container 131 is in the extended state (see FIG. 2), the air valves 1341 and 1344 are closed to supply the liquid to the variable container 131. Stopped (step S11). In the present embodiment, the amount of liquid supplied to the variable container 131 by one extension is 30 ml, and the volume of the variable container 131 in the extended state is 100 ml.

  Subsequently, whether or not air remains in the variable container 131 and the flow path 11 is confirmed by the operator (step S12). If air remains, the air valve 1331 is opened by the sequence controller 152. Then, the supply of air between the variable vessel 131 and the pressure vessel 132 by the electropneumatic regulator 133 is started, and the pressure in the pressure vessel 132 (that is, the pressure around the variable vessel 131) increases. Thereby, the variable container 131 is compressed, and the air in the variable container 131 and the flow path 11 is discharged from the downstream side of the flow path 11 to the outside of the liquid supply apparatus 1.

  When the displacement sensor 135 detects that the variable container 131 is in a compressed state, the air valve 1331 is closed, and the discharge of air from the variable container 131 and the flow path 11 is stopped (step S121). Returning to S11, the supply of the liquid to the variable container 131 is performed again. In the liquid supply apparatus 1, the supply of the liquid to the variable container 131 and the supply of the air from the variable container 131 and the flow path 11 until the air is completely discharged from the variable container 131 and the flow path 11 and the liquid is filled. The discharge (steps S11 to S121) is repeated.

  When the air is completely discharged from the variable container 131 and the flow path 11 (step S12), the downstream end of the flow path 11 is connected to the supply target device and the like, and the electropneumatic regulator 133 is the same as in step S121. As a result, air is supplied to the inside of the pressure resistant container 132, pressure is applied to the variable container 131, and the expanded variable container 131 is compressed, so that the liquid stored in the variable container 131 is sent to the flow path 11. And supplied to other devices (step S13). In the liquid supply apparatus 1, while the liquid is being sent from the variable container 131 by the pump mechanism 13, the flow control shown in FIG. 8 is continuously performed. Next, the flow of flow control by the liquid supply apparatus 1 will be described.

  In the liquid supply apparatus 1, when the delivery of the liquid from the pump mechanism 13 to the flow path 11 is started, the flow meter 14 disposed on the downstream side of the pump mechanism 13 causes the liquid per unit time flowing through the flow path 11 to be per unit time. The flow rate is measured and sent to the feedback controller 151 of the control unit 15 (step S131). Subsequently, the feedback controller 151 determines whether or not the measured flow rate obtained by the flow meter 14 is equal to a set flow rate set in advance by inputting from the outside (step S132).

  When the measured flow rate is different from the set flow rate, from the feedback controller 151 to the electropneumatic regulator 133 of the pump mechanism 13 based on the measured flow rate so that the flow rate per unit time of the liquid flowing through the flow path 11 becomes the set flow rate. The pressure command value is given as an electrical signal, and the pressure applied to the variable container 131 is controlled (step S133). Further, when the measured flow rate is the same as the set flow rate, the pressure applied to the variable container 131 is maintained as it is. In the present embodiment, PID control is used as a control method by the feedback controller 151. The electric signal sent from the feedback controller 151 to the electropneumatic regulator 133 is a current of 4 to 20 mA.

  In the pump mechanism 13, as the variable container 131 is compressed, the repulsive force of the variable container 131 due to the bellows 1311 (that is, the force to push back the compression) gradually increases. The electropneumatic regulator 133 is controlled so as to gradually increase the pressure between the container 132 and the measured flow rate is made equal to the set flow rate.

  In the liquid supply apparatus 1, it is determined whether or not the liquid delivery from the pump mechanism 13 has been completed (step S 134), and the flow rate is measured while the liquid delivery from the variable container 131 is being performed. The process of controlling the pressure applied to 131 (steps S131 to S133) is repeated. As described above, in the liquid supply apparatus 1, the liquid is supplied to other apparatuses and the like while the flow rate is controlled so that the flow rate of the liquid flowing through the flow path 11 becomes the set flow rate. When the displacement sensor 135 detects that the variable container 131 is in a compressed state, the air valve 1331 is closed to finish sending the liquid from the variable container 131 to the flow path 11 (step S134). The flow rate measurement by the meter 14 and the control of the electropneumatic regulator 133 by the control unit 15 are also finished, and the supply of the liquid to other devices and the like is finished. In the present embodiment, the liquid supply amount by one compression of the variable container 131 is 30 ml.

  Although not shown in FIG. 7, when the liquid supply by the liquid supply apparatus 1 is repeated, the process returns to step S11 after step S13, and the variable container 131 is expanded again to supply the liquid from the liquid supply source 12. Aspirate. In this case, when the variable container 131 is in the extended state, air does not remain in the variable container 131 and the flow path 11 and the liquid is filled, so that air is discharged from the variable container 131 and the flow path 11. The process (steps S12 and S121) to be performed is omitted, and steps S11 and S13 are repeated.

  As described above, in the liquid supply apparatus 1, while the pressure is applied to the variable container 131 of the pump mechanism 13 and the liquid in the variable container 131 is sent to the flow path 11, the flow meter 11 causes the flow path 11 to flow. The pressure applied to the variable container 131 is controlled by the feedback controller 151 so that the flow rate per unit time of the liquid flowing through the liquid is measured and the measured flow rate becomes the set flow rate. In the liquid supply apparatus 1, by controlling the pressure applied to the variable container 131 with high accuracy, it is possible to supply a liquid with a minute flow rate while accurately controlling the flow rate.

  Further, in the liquid supply apparatus 1, the variable container 131 of the pump mechanism 13 and the pressure drop tube 143 of the flow meter 14 are made of resin having high durability against various liquids, and have various configurations that come into contact with other liquids. In addition, since it is made of a highly durable material such as a fluororesin, various types of liquid can be supplied.

  In the pump mechanism 13, since the variable container 131 includes the bellows 1311, the volume of the variable container 131 can be changed easily, that is, with a small force. Further, when the variable container 131 is compressed, the bellows 1311 is contracted as a whole, and the bending of the variable container 131 during the compression is prevented from being concentrated on a part. Therefore, the compression of the variable container 131 when the pump mechanism 13 is used. Deterioration due to repeated stretching can be suppressed.

  In the pump mechanism 13, the pressure between the pressure vessel 132 and the variable vessel 131 is adjusted with high responsiveness and high accuracy by adjusting the pressure in the pressure vessel 132 in which the variable vessel 131 is accommodated by the electropneumatic regulator 133. Can be controlled.

  In the pump mechanism 13, the lower end 1313 of the variable container 131 is a free end as shown in FIG. FIG. 9 is a diagram illustrating a part of the pump mechanism 93 whose lower end portion of the variable container is not a free end as a comparative example. In the pump mechanism 93 of the comparative example, a cylindrical cylinder portion 9322 is provided at the lower portion of the pressure vessel 932, and the inside of the cylinder portion 9322 passes through the bottom portion of the pressure vessel 932 and is connected to the lower end portion 9313 of the variable vessel 931. A piston 9323 is provided. The piston 9323 includes a disk-shaped bottom portion 9324 disposed inside the cylinder portion 9322 and a columnar shaft portion 9325 that protrudes upward from the bottom portion 9324 and is inserted into the through-hole 9326 in the bottom portion of the pressure-resistant container 932. . The space between the side surface of the bottom portion 9324 and the inner surface of the cylinder portion 9322 and the space between the outer surface of the shaft portion 9325 and the inner surface of the through hole 9326 are sealed so as not to leak air.

  In the pump mechanism 93, air is supplied between the pressure-resistant container 932 and the variable container 931 and the variable container 931 is compressed, so that the liquid in the variable container 931 is sent out. Air is supplied to the space surrounded by the bottom of the pressure vessel 932, the cylinder portion 9322, and the bottom 9324 of the piston 9323, and the bottom 9324 of the piston 9323 is relatively separated from the bottom of the pressure vessel 932, whereby the variable vessel The liquid 931 is extended and the liquid is supplied to the variable container 931.

  In the pump mechanism 93, the piston 9323 moves up and down together with the lower end portion 9313 of the variable container 931 at any time of sending and supplying the liquid from the variable container 931. When the piston 9323 is moved, the bottom portion 9324 is rubbed against the inner surface of the cylinder portion 9322 and the shaft portion 9325 is rubbed against the inner surface of the through-hole 9326 to generate sliding resistance. So-called chattering or shaving occurs in the vertical movement of the lower end portion 9313 of the 931, and the compression and extension of the variable container 931 become unstable.

  On the other hand, in the pump mechanism 13 according to the above-described results, the lower end 1313 of the variable container 131 is a free end as shown in FIG. By making the sliding resistance very small even when sliding occurs, the variable container 131 is stably compressed (that is, preventing chatter and shackles). be able to. As a result, the liquid supply apparatus 1 can control the flow rate of the supplied liquid with higher accuracy.

  In the pump mechanism 13, since the displacement sensor 135 that detects the displacement of the lower end portion 1313 of the variable container 131 is provided, the operation of the variable container 131 inside the pressure-resistant container 132 can be monitored. Reliability can be improved. Further, since the liquid leakage sensor 136 is provided at the bottom of the pressure resistant container 132, even if liquid leaks from the variable container 131, the leakage can be detected promptly. The reliability of operation can be further improved.

  In the flow meter 14, since the relationship between the differential pressure and the flow rate at both ends of the pressure loss tube 143 is almost proportional because the liquid flow is a laminar flow, the resolution of the differential pressure and the flow rate changes greatly. The flow rate measurement accuracy can be made substantially constant regardless of the magnitude of the differential pressure. Compared to other measurements that use a turbulent flow area in which the flow rate is approximately proportional to the square root of the differential pressure, the amount of change in the flow rate relative to the change in the differential pressure is large, so that not only can the measurement accuracy be improved, The range of flow rate that can be measured can be expanded. In the flow meter 14, the Reynolds number of the flow in the pressure drop tube 143 is set to 2000 or less to avoid a transition region where the flow state becomes unstable, and the flow is surely made laminar to obtain the differential pressure, thereby obtaining the liquid pressure. Even when the flow rate is very small, the flow rate can be measured stably with high accuracy. As a result, the liquid supply apparatus 1 can supply a liquid with a minute flow rate while controlling the flow rate with higher accuracy.

  In the flow meter 14, the inner diameter of the pressure loss tube 143 is extremely reduced even when measuring the flow rate of a minute flow rate liquid by gradually decreasing the liquid pressure by using the long pressure loss tube 143 as the pressure loss part. A significant differential pressure can be obtained. Therefore, the inner diameter of the pressure loss tube 143 can be made relatively large, and the flow rate of the liquid flowing through the pressure loss tube 143 does not need to be extremely increased. As a result, the pressure loss tube 143 can be prevented from being clogged with foreign matter, and the occurrence of cavitation in the vicinity of the downstream end portion of the pressure loss tube 143 can be prevented. As described above, the flow meter 14 is particularly suitable for the liquid supply apparatus 1 that requires highly accurate flow measurement of a liquid having a minute flow rate.

  FIG. 10 is a diagram showing a configuration of a liquid supply apparatus 1a according to the second embodiment of the present invention. As shown in FIG. 10, the liquid supply apparatus 1 a has the same structure as the liquid supply apparatus 1 shown in FIG. 1, and further includes another pump mechanism 13 a having the same structure as the pump mechanism 13. In the following description, in order to distinguish between the pump mechanism 13 and the pump mechanism 13a, they are referred to as “first pump mechanism 13” and “second pump mechanism 13a”, respectively. Other configurations are the same as those in FIG. 1, and the same reference numerals are given in the following description. In FIG. 10, the parallel oblique lines of the cross section are omitted.

  In the liquid supply apparatus 1a, the flow path 11 is divided into two parts between the liquid supply source 12, the first pump mechanism 13 and the second pump mechanism 13a, and the first pump mechanism 13, the second pump mechanism 13a and the flow meter are divided. The flow path 11 divided | segmented between 14 merges. In the part divided into two of the flow path 11, the first pump mechanism 13 is connected between the first check valve 112 and the second check valve 113 provided on one divided flow path, and on the other divided flow path. The second pump mechanism 13a is connected between the third check valve 112a and the fourth check valve 113a provided in the first check valve 112a. Moreover, the flow meter 14 for measuring the flow rate per unit time of the liquid flowing in the flow path 11 is provided on the downstream side of the junction of the divided flow paths.

  Similarly to the first pump mechanism 13, the second pump mechanism 13a is a deformable resin variable container 131a (hereinafter referred to as "second variable container 131a". In order to distinguish from this, the first pump mechanism 13 variable containers 131 are referred to as “first variable containers 131”), a pressure container 132a that houses the second variable container 131a, and a pressure between the pressure container 132a and the second variable container 131a. An electropneumatic regulator 133a is provided.

  Similar to the first variable container 131, the second variable container 131a includes a bellows 1311a, and the lower end of the bellows 1311a is a free end. Further, similarly to the pressure vessel 132 shown in FIG. 2, the pressure vessel 132a includes a displacement sensor for detecting the displacement of the lower end portion of the bellows 1311a with respect to the pressure vessel 132a, and liquid leakage from the second variable vessel 131a. A liquid leakage sensor is provided to detect this when there is any. Also in the second pump mechanism 13a, the displacement sensor detects whether the second variable container 131a is in a compressed state, in an expanded state, or in an intermediate state.

  The pressure vessel 132a is connected to the electropneumatic regulator 133a via the air valve 1331a, and is connected to the ejector 134 of the first pump mechanism 13 via the air valve 1341a. That is, the first pump mechanism 13 and the second pump mechanism 13a share the ejector 134. The air valves 1331a and 1341a are driven by electromagnetic valves 1332a and 1342a. In the second pump mechanism 13 a, these valves, the electropneumatic regulator 133 a and the ejector 134 are controlled by the control unit 15, so that the second variable container 131 a is compressed and expanded, and sucks liquid from the liquid supply source 12. The liquid is stored and delivered to the flow path 11.

  In the liquid supply apparatus 1a, under the control of the control unit 15, one of the first variable container 131 of the first pump mechanism 13 and the second variable container 131a of the second pump mechanism 13a is compressed, and in parallel therewith. The other expansion is alternately performed on the first variable container 131 and the second variable container 131a, so that the liquid is continuously supplied.

  11 and 12 are diagrams showing a flow of liquid supply by the liquid supply apparatus 1a. FIG. 13 is a diagram showing how the operations of the first pump mechanism 13 and the second pump mechanism 13a are switched in each step after step S23, which will be described later, and the step symbols are given to the positions corresponding to the steps. ing. Hereinafter, the operation flow of the liquid supply apparatus 1a will be described with reference to FIGS.

  When the liquid is supplied by the liquid supply device 1a, as in the first embodiment, the operator first fills the first pump mechanism 13, the second pump mechanism 13a, and the flow path 11 with the liquid. Done. First, the air between the first variable container 131 and the pressure container 132 is discharged by the ejector 134, the pressure container 132 is depressurized, and the first variable container 131 is expanded from the compressed state (see FIG. 3) (FIG. 2). The liquid is sucked from the liquid supply source 12 and stored in the first variable container 131. In parallel with this, the air between the second variable container 131a and the pressure container 132a is discharged by the ejector 134, the pressure container 132a is decompressed, and the second variable container 131a is changed from the compressed state to the expanded state. By being expanded, the liquid is sucked from the liquid supply source 12, supplied to the second variable container 131a, and stored in the extended second variable container 131a (step S21).

  When the first variable container 131 and the second variable container 131a are in the extended state, it is determined whether air remains in the first variable container 131, the second variable container 131a, and the flow path 11 (step S22). Is determined to remain, the electropneumatic regulators 133 and 133a cause air to flow between the first variable container 131 and the pressure container 132 and between the second variable container 131a and the pressure container 132a. The pressure-resistant containers 132 and 132a are supplied and pressurized, and the first variable container 131 and the second variable container 131a are compressed from the expanded state to the compressed state, and the first variable container 131, the second variable container 131a, and the flow path. 11 is discharged from the downstream side of the flow path 11 to the outside of the liquid supply apparatus 1a (step S221).

  If the 1st variable container 131 and the 2nd variable container 131a are made into a compression state, it will return to step S21 and the supply of the liquid to the 1st variable container 131 and the 2nd variable container 131a will be performed again. In the liquid supply apparatus 1a, liquid is supplied to the first variable container 131 and the second variable container 131a until the air is completely discharged from the first variable container 131, the second variable container 131a, and the flow path 11 and is filled with the liquid. And the discharge of air from the first variable container 131, the second variable container 131a and the flow path 11 (steps S21 to S221) are repeated.

  When the air is completely discharged from the first variable container 131, the second variable container 131a, and the flow path 11 (step S22), the air is supplied into the pressure-resistant container 132 by the electropneumatic regulator 133 of the first pump mechanism 13. Then, pressure is applied to the first variable container 131, and compression of the first variable container 131 in the expanded state is started. Thereby, the delivery of the liquid stored in the first variable container 131 to the flow path 11 is started, and the liquid is supplied to other devices and the like (step S23).

  In the second pump mechanism 13a, the air into the pressure-resistant container 132a by the electropneumatic regulator 133a is shortly before the compression of the first variable container 131 is stopped and the liquid delivery from the first pump mechanism 13 is stopped. Is started, and compression of the second variable container 131a in the expanded state is started. Thereby, the liquid stored in the second variable container 131a is sent to the flow path 11 in parallel with the liquid from the first variable container 131 (step S24).

  Subsequently, the compression of the first variable container 131 is stopped in the first pump mechanism 13 (step S25). In the liquid supply device 1a, the compression of the second variable container 131a is continued in the second pump mechanism 13a even after the compression of the first variable container 131 is stopped, so that the liquid is sent to the flow path 11 without interruption. The In the first pump mechanism 13, as soon as the compression of the first variable container 131 is stopped, the ejector 134 starts to discharge air from the pressure-resistant container 132, and the compressed first variable container 131 is expanded. Thus, the liquid is sucked from the liquid supply source 12 to the first variable container 131 and stored in the first variable container 131 (step S26).

  In the first pump mechanism 13, the discharge of the air from the pressure-resistant container 132 by the ejector 134 is stopped before the compression of the second variable container 131 a is stopped and the liquid delivery from the second pump mechanism 13 a is stopped. The extension of the first variable container 131 is stopped (step S27). Thereafter, shortly before the compression of the second variable container 131a is stopped, the supply of air into the pressure resistant container 132 by the electropneumatic regulator 133 is started, and the compression of the first variable container 131 in the expanded state is started. As a result, the liquid stored in the first variable container 131 is sent to the flow path 11 in parallel with the liquid from the second variable container 131a (step S31).

  Subsequently, the compression of the second variable container 131a is stopped in the second pump mechanism 13a (step S32). In the liquid supply apparatus 1a, the compression of the first variable container 131 is continued in the first pump mechanism 13 even after the compression of the second variable container 131a is stopped, so that the liquid is sent to the flow path 11 without interruption. The In the second pump mechanism 13a, as soon as the compression of the second variable container 131a is stopped, the ejector 134 starts to discharge air from the pressure-resistant container 132a, and the compressed second variable container 131a is expanded to have a volume. Increases, the liquid is sucked from the liquid supply source 12 to the second variable container 131a and stored in the second variable container 131a (step S33).

  In the second pump mechanism 13a, before the compression of the first variable container 131 is stopped and the liquid delivery from the first pump mechanism 13 is stopped, the discharge of air from the pressure-resistant container 132a by the ejector 134 is stopped. The extension of the second variable container 131a is stopped (step S34). Then, returning to step S24, shortly before the compression of the first variable container 131 is stopped, the supply of air into the pressure-resistant container 132a by the electropneumatic regulator 133a is started, and the second variable container in the expanded state is started. Pressure is applied to 131a and compression starts. Then, as the volume of the second variable container 131a decreases, the liquid stored in the second variable container 131a is sent to the flow path 11 in parallel with the liquid from the first variable container 131 (step S24). ).

  Subsequently, the compression of the first variable container 131 is stopped (step S25), and before the compression of the second variable container 131a is stopped, the first variable container 131 is expanded and the liquid is sucked (step S26). In addition, after the first variable container 131 is compressed and the delivery of the liquid is started, the compression of the second variable container 131a is stopped (steps S31 and S32). Thereafter, before the compression of the first variable container 131 is stopped, the second variable container 131a is expanded and the liquid is sucked (steps S33 and S34), and the process returns to step S24 again.

  Thus, in the liquid supply apparatus 1a, steps S24 to S34 are repeated until it is determined that the supply of the liquid is completed. In other words, the delivery of the liquid from the second variable container 131a to the flow path and the storage of the liquid to the first variable container 131 performed in parallel and the flow from the first variable container 131 performed in substantially parallel. The delivery of the liquid to the path and the storage of the liquid in the second variable container 131a are alternately repeated. As a result, in the liquid supply apparatus 1a, the liquid is continuously delivered from the first pump mechanism 13 and / or the second pump mechanism 13a. In the liquid supply apparatus 1a, the second variable container 131a may be compressed first, and then the first variable container 131 may be compressed. In addition, the liquid filling operation that is performed first when supplying the liquid is performed by alternately compressing one of the first variable container 131 and the second variable container 131a and extending the other in parallel to the two variable containers. It may be performed by repeating.

  In the liquid supply apparatus 1a, while the liquid is being delivered by the first pump mechanism 13 and the second pump mechanism 13a, that is, between step S23 shown in FIGS. 11 and 12 and repeated steps S24 to S34. The flow control shown in FIG. 14 is continuously performed. Next, the flow of flow control by the liquid supply apparatus 1a will be described.

  In the liquid supply apparatus 1a, when the delivery of the liquid from the first pump mechanism 13 to the flow path 11 is started in step S23 (see FIGS. 11 and 13), the flowmeter is the same as in the first embodiment. 14, the flow rate of the liquid flowing through the flow path 11 is measured and sent to the feedback controller 151 of the control unit 15 (step S41). Subsequently, it is determined whether or not the measured flow rate obtained by the flow meter 14 is equal to the set flow rate (step S42).

  When the measured flow rate is different from the set flow rate, the feedback controller 151 controls the electropneumatic regulator 133 of the first pump mechanism 13 to control the pressure applied to the variable container 131 so that the measured flow rate becomes the set flow rate. (Step S43). Also in the second embodiment, PID control is used as a control method by the feedback controller 151.

  In the liquid supply apparatus 1a, it is determined whether or not the delivery of the liquid from the first pump mechanism 13 and the second pump mechanism 13a is finished (step S44). If not finished, the process returns to step S41, and the flow rate is reduced. The process of measuring and controlling the pressure applied to the first variable container 131 and / or the second variable container 131a (steps S41 to S43) is repeated.

  In the liquid supply apparatus 1a, during the steps S23 to S24 shown in FIG. 13 and between the steps S32 to S24, the first pump mechanism 13 is controlled to make the measured flow rate equal to the set flow rate. In addition, during steps S25 to S31, the flow rate is measured by the flow meter 14 provided on the downstream side of the second pump mechanism 13a, and the second pump is set so that the measured flow rate becomes the set flow rate based on the measured flow rate. The electropneumatic regulator 133a of the mechanism 13a is controlled, and the pressure applied to the second variable container 131a is controlled.

In addition, during steps S24 to S25 and between steps S31 to S32, the electropneumatic regulators 133 and 133a of the first pump mechanism 13 and the second pump mechanism 13a are controlled based on the flow rate measured by the flow meter 14. The pressure applied to the first variable container 131 and the second variable container 131a is controlled in parallel. In other words, in the liquid supply apparatus 1a, the fixed time after the start of the delivery of the liquid from the first variable container 131 and the fixed time before the end of the delivery are the fixed time before the end of the delivery of the liquid from the second variable container 131a and overlaps transmission start a certain time after the respective in certain time these mutually overlapping, so that the measured flow rate by the flow meter 14 is equal to the set flow rate, equal to the first variable container 131 and the second variable chamber 131a Pressure is applied and controlled.

  FIG. 15 is a diagram showing a change in the flow rate per unit time of the liquid flowing through the flow path 11 in the liquid supply apparatus 1a. In the liquid supply device 1a, when the compression of one of the first variable container 131 and the second variable container 131a is continued and the other compression is started (that is, steps S24 and S31), the compression starts. The pressure command value given to the electropneumatic regulator to be applied to the variable container on the side to be processed is the same as the pressure applied to one of the variable containers being compressed as described above. At this time, the variable container on the side where compression is started is in an expanded state as compared with the variable container being compressed, and the repulsive force by the bellows during compression is small, so the flow rate of the liquid delivered to the flow path 11 However, it becomes slightly larger than the set flow rate during steps S24 to S25 and between steps S31 to S32 as shown in FIG.

  However, in the liquid supply device 1a, the flow rate control is performed based on the flow rate measured by the flow meter 14 as described above, and even a slight disturbance of such a flow rate can be quickly suppressed. Such a large flow rate fluctuation is prevented. Thus, the liquid supply apparatus 1a can always maintain a substantially constant flow rate.

  As described above, in the liquid supply apparatus 1a, one of the first variable container 131 of the first pump mechanism 13 and the second variable container 131a of the second pump mechanism 13a is compressed, and in parallel therewith. The other expansion is alternately performed, the flow rate of the liquid flowing through the flow path 11 is measured by the flow meter 14, and the pressure applied to the first variable container 131 and the second variable container 131a is further determined based on the measured flow rate. Controlled by a feedback controller 151. In the liquid supply apparatus 1a, the pressure applied to the first variable container 131 and the second variable container 131a is controlled with high accuracy, and a minute flow rate of liquid is continuously supplied over a long period of time while accurately controlling the flow rate. can do.

  Further, in the liquid supply apparatus 1a, before the compression of one of the first variable container 131 and the second variable container 131a is stopped, the other expansion is stopped and the compression is started. In this way, the first and second variable containers 131a and 131a are compressed by pressure control by overlapping the start and end of the liquid delivery operation by the first pump mechanism 13 and the second pump mechanism 13a. Flow rate fluctuations that occur during switching can be easily suppressed. As a result, continuous supply of a liquid with a minute flow rate can be performed stably.

  In the liquid supply device 1a, the second pump mechanism 13a has the same structure as the first pump mechanism 13, and the second variable container 131a is formed of a resin having high durability against various liquids. The liquid can be supplied. Moreover, the 2nd variable container 131a provided with the bellows 1311a can change a volume easily similarly to the 1st variable container 131, and can also suppress degradation by repetition of compression and expansion | extension.

  In the second pump mechanism 13a, since the electropneumatic regulator 133a is used to compress the second variable container 131a, the pressure between the pressure-resistant container 132a and the second variable container 131a can be controlled with high responsiveness and high accuracy. it can. In addition, since the lower end portion of the second variable container 131a is a free end, the second variable container 131a can be stably compressed, so that the flow rate of the liquid to be supplied can be controlled with higher accuracy. . Furthermore, by providing the pressure sensor 132a with a displacement sensor and a liquid leakage sensor, the reliability of the operation of the liquid supply apparatus 1 can be improved.

  In the liquid supply apparatus 1a, similarly to the first embodiment, the flow meter 14 can stably measure the flow rate with high accuracy even when the flow rate of the liquid is very small.

  Next, a liquid supply apparatus according to a third embodiment of the present invention will be described. In the liquid supply apparatus according to the third embodiment, a pump mechanism 13b shown in FIG. 16 is provided instead of the pump mechanism 13 of the liquid supply apparatus 1 shown in FIG. Other configurations are the same as those in FIG. 1, and the same reference numerals are given in the following description.

  In the pump mechanism 13b of the liquid supply apparatus according to the third embodiment, the variable container 131b is compressed and expanded by a motor that is a drive source different from the pump mechanism 13 of the liquid supply apparatus 1 shown in FIG. As shown in FIG. 16, in the pump mechanism 13b, instead of the pressure-resistant container 132, electropneumatic regulator 133, ejector 134, various air valves and electromagnetic valves of the pump mechanism 13 shown in FIG. A moving mechanism 137 that compresses or expands the variable container 131b by moving the container vertically and a motor 138 that drives the moving mechanism 137 are provided.

  The moving mechanism 137 moves the moving plate 1371 connected to the lower end of the variable container 131b, the ball screw 1372 extending in the vertical direction, the nut 1373 fixed to the moving plate 1371 and the ball screw 1372 being inserted, and the moving plate 1371 up and down. A guide 1374 for guiding in the direction and a timing belt 1375 for connecting the ball screw 1372 to the motor 138 are provided. The motor 138 can control the output torque, and a torque control amplifier 1381 is connected to the motor 138.

  In the moving mechanism 137, the ball screw 1372 is rotated by the motor 138, so that the moving plate 1371 moves smoothly along the guide 1374 in the vertical direction. When the moving plate 1371 is moved upward by the motor 138, the lower end portion of the variable container 131b is also moved upward (that is, in a direction approaching the upper end portion of the variable container 131b), and pressure is applied to the variable container 131b to change the variable container 131b. The liquid inside is sent to the flow path 11. In other words, the moving mechanism 137 serves as a pressurizing mechanism that applies pressure to the variable container 131b by torque output from the motor 138.

  Further, when the moving plate 1371 is moved downward by the motor 138, the lower end portion of the variable container 131b is separated from the upper end portion, and the variable container 131b (inside) is decompressed. Thereby, the liquid is sucked from the liquid supply source 12 (see FIG. 1), supplied to the variable container 131b, and stored in the variable container 131b.

  In the liquid supply apparatus according to the third embodiment, the variable container 131b is compressed by the pump mechanism 13b, so that the liquid in the variable container 131b is sent to the flow path 11 and the liquid flows through the flow path 11. Meanwhile, the flow rate per unit time of the liquid flowing through the flow path 11 is measured by the flow meter 14 (see FIG. 1) arranged on the downstream side of the pump mechanism 13b. Based on the measured flow rate, the feedback controller 151 (see FIG. 1) of the control unit 15 controls the output torque of the motor 138 via the torque control amplifier 1381 so that the measured flow rate becomes the set flow rate. The pressure applied to the is controlled.

  As described above, in the liquid supply device according to the third embodiment, the pump mechanism 13b can be driven without using a compressed air supply source, a vacuum source, or the like, so that the configuration of the liquid supply device is simplified. be able to.

  Next, as a fourth embodiment of the present invention, a substrate processing apparatus 2 including the liquid supply apparatus 1 shown in FIG. 1 will be described with reference to FIG. The substrate processing apparatus 2 is a so-called single wafer processing apparatus that performs etching on a single semiconductor substrate 9 (hereinafter simply referred to as “substrate 9”).

  As shown in FIG. 17, the substrate processing apparatus 2 includes a first flow path 21 through which pure water flows and a second flow path 22 through which hydrofluoric acid flows, and the first flow path 21 and the second flow path 22 are It merges on the downstream side of both flow paths. A mixing valve 241 is provided at the confluence of the first flow path 21 and the second flow path 22, and pure water from the first flow path 21 and hydrofluoric acid from the second flow path 22 are mixed to process the treatment liquid. Generated.

  The first flow path 21 is connected to an external pure water supply device via a valve 211 and a regulator 212 on the upstream side. The liquid supply apparatus 1 according to the first embodiment for supplying hydrofluoric acid is provided on the upstream side of the second flow path 22. Hereinafter, each component of the liquid supply apparatus 1 will be described with reference to the reference numerals in FIG.

  In the substrate processing apparatus 2, a third flow path 24 through which a processing liquid that is a mixed liquid of pure water and hydrofluoric acid flows is provided on the downstream side of the mixing valve 241. A substrate holding unit 26 that holds the substrate 9 is disposed on the downstream side of the junction of the first flow path 21 and the second flow path 22. In addition, above the substrate holding unit 26, a nozzle 27 that is connected to the downstream side of the third flow path 24 and that supplies a processing liquid onto the substrate 9 is provided.

  The substrate holding unit 26 includes a chuck 261 that holds the substantially disk-shaped substrate 9 from the lower side and the outer peripheral side, a rotating mechanism 262 that rotates the substrate 9, and a processing cup 263 that covers the outer periphery of the chuck 261. The rotation mechanism 262 includes a shaft 2621 connected to the lower side of the chuck 261 and a motor 2622 for rotating the shaft 2621. When the motor 2622 is driven, the substrate 9 rotates together with the shaft 2621 and the chuck 261. The processing cup 263 is disposed on the outer periphery of the chuck 261 and is provided on the substrate 9 provided on the side wall 2631 that prevents the processing liquid supplied on the substrate 9 from scattering to the periphery and the lower portion of the processing cup 263. A discharge port 2632 for discharging the treated liquid is provided.

  In the substrate processing apparatus 2, pure water is supplied from the pure water supply apparatus to the first flow path 21 by opening the valve 211. At the same time, the pump mechanism 13 (see FIG. 1) of the liquid supply apparatus 1 is driven and pressure is applied to the variable container 131 in which hydrofluoric acid is stored in advance, so that the hydrofluoric acid is transferred from the variable container 131 to the flow path 11. Is delivered and supplied to the second flow path 22. The hydrofluoric acid supplied to the second flow path 22 is mixed with the pure water supplied to the first flow path 21 in the mixing valve 241 to generate a treatment liquid that is dilute hydrofluoric acid.

  The processing liquid generated in the mixing valve 241 is supplied to the nozzle 27 through the third flow path 24 and is discharged from the nozzle 27 toward the center of the substrate 9 by a necessary amount. The substrate 9 is held and rotated by the substrate holding unit 26, and the processing liquid supplied from the nozzle 27 spreads over the entire upper surface of the substrate 9 while moving the upper surface of the substrate 9 to the outer peripheral side by centrifugal force. Etching 9 is performed. The processing liquid that has moved to the outer edge of the substrate 9 is received by the side wall 2631 of the processing cup 263 away from the substrate 9, or falls directly to the bottom of the processing cup 263 and is discharged from the discharge port 2632.

  In the liquid supply apparatus 1 of the substrate processing apparatus 2, the flow rate of hydrofluoric acid flowing at a minute flow rate is stably measured with high accuracy by the flow meter 14 (see FIG. 1), and measured by the control unit 15 (see FIG. 1). By controlling the pressure applied to the variable container 131 of the pump mechanism 13 based on the flow rate and a preset set flow rate, a very small amount of hydrofluoric acid is supplied to the second flow path 22 while accurately controlling the flow rate. can do. As described above, in the substrate processing apparatus 2, a minute supply amount of hydrofluoric acid to the mixing valve 241 is controlled with high accuracy, and a processing liquid in which hydrofluoric acid is accurately mixed at a desired concentration is generated. As a result, the substrate processing apparatus 2 can perform etching on the substrate 9 with a processing liquid in which hydrofluoric acid is accurately mixed at a desired concentration. Etching is performed with dilute hydrofluoric acid whose concentration is controlled with high accuracy, whereby the etching rate can be controlled with high accuracy and a more preferable processing result can be obtained. In addition, the etching rate can be lowered to suppress variations in processing time between the center and the outer edge side of the substrate 9, and the uniformity of the etching quality in the entire substrate 9 can be improved.

  Next, as a fifth embodiment of the present invention, a substrate processing apparatus 2a including the liquid supply apparatus 1a shown in FIG. 10 will be described with reference to FIG. The substrate processing apparatus 2a is a so-called batch type processing apparatus that performs etching on a plurality of substrates 9 simultaneously. As shown in FIG. 18, in the substrate processing apparatus 2a, the liquid supply apparatus 1a shown in FIG. 10 is provided instead of the liquid supply apparatus 1 of the substrate processing apparatus 2 shown in FIG. In place of 27, the processing liquid is stored on the downstream side of the third flow path 24 (that is, downstream of the confluence of the first flow path 21 and the second flow path 22) and the substantially disk-shaped substrate 9 is stored. Is provided with a treatment tank 25 in which a plurality of the baths are immersed in a standing posture. Other configurations are the same as those in FIG. 17, and the same reference numerals are given in the following description. Each component of the liquid supply apparatus 1a will be described with reference to the reference numerals in FIG.

  As shown in FIG. 18, the substrate processing apparatus 2 a joins the first flow path 21 through which pure water flows and hydrofluoric acid through the mixing valve 241 together with the first flow path 21, as in the fourth embodiment. The second flow path 22, the liquid supply apparatus 1 a according to the second embodiment that is provided upstream of the second flow path 22 and supplies hydrofluoric acid to the second flow path 22, and downstream of the mixing valve 241 A third flow path 24 is provided, through which a treatment liquid that is a mixed liquid of pure water and hydrofluoric acid flows.

  In the substrate processing apparatus 2a, as in the fourth embodiment, the pure water supplied to the first flow path 21 and the hydrofluoric acid supplied to the second flow path 22 are mixed in the mixing valve 241. A treatment liquid that is dilute hydrofluoric acid is produced. At this time, in the liquid supply apparatus 1a, the flow rate of hydrofluoric acid flowing at a minute flow rate is stably measured with high accuracy by the flow meter 14 (see FIG. 10), and the measured flow rate is measured by the control unit 15 (see FIG. 10). By controlling the pressure applied to the first variable container 131 and the second variable container 131a (see FIG. 10) based on the set flow rate, the second flow path 22 is controlled while the flow rate of the fine flow hydrofluoric acid is accurately controlled. Is supplied to the mixing valve 241. As a result, a treatment liquid in which hydrofluoric acid is accurately mixed at a desired concentration is generated.

  The processing liquid generated in the mixing valve 241 is supplied from the bottom to the processing tank 25 through the third flow path 24. In the processing tank 25, the plurality of substrates 9 held in the processing tank 25 are gradually immersed from below in the processing liquid supplied to and stored in the processing tank 25, thereby etching the substrate 9.

  In the substrate processing apparatus 2a as well, as in the fourth embodiment, the substrate 9 can be etched with a processing liquid in which hydrofluoric acid is accurately mixed at a desired concentration. Etching is performed with dilute hydrofluoric acid whose concentration is controlled with high accuracy, whereby the etching rate can be controlled with high accuracy and a more preferable processing result can be obtained. In addition, the etching rate can be lowered to suppress variations in processing time between the center and the outer edge side of the substrate 9, and the uniformity of the etching quality in the entire substrate 9 can be improved.

  In the substrate processing apparatus 2a, a small amount of hydrofluoric acid can be continuously supplied over a long period of time while accurately controlling the flow rate by the liquid supply apparatus 1a, so that a large amount of processing liquid is required for one process. It can be said that it is particularly suitable for batch-type etching (and other substrate processing). Further, in the liquid supply apparatus 1a, the first variable container 131 and the second variable container 131a are compressed by overlapping the start and end of the liquid delivery operation by the first pump mechanism 13 and the second pump mechanism 13a. Since the flow rate fluctuation generated at the time of switching can be easily suppressed, the processing liquid used for etching the substrate 9 can be easily maintained at a desired concentration.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  For example, the variable container provided in each pump mechanism of the liquid supply apparatus according to the above embodiment may be formed of various materials other than resin. In addition, each variable container does not necessarily need to be provided with a bellows. For example, the entire variable container may be substantially spherical. Also in this case, in the liquid supply apparatus according to the first and second embodiments, the substantially spherical variable container to which pressure is applied in the pressure resistant container is compressed, and the liquid is delivered to the flow path 11.

  In the liquid supply devices according to the first and second embodiments, when the variable container is extended and the liquid is sucked from the liquid supply source 12, it is not always necessary to reduce the pressure until the pressure inside the pressure container becomes negative. . For example, the liquid may be sucked from the liquid supply source 12 by the bellows extending due to the repulsive force of the bellows compressed by reducing the pressure around the variable container to some extent. In addition, the liquid supply source 12 may be sealed and a pressurization mechanism may be provided, and the liquid in the liquid supply source 12 may be pressurized and sent to the pump mechanism to supply the liquid to the variable container. .

  In the liquid supply apparatus 1a according to the second embodiment, two pump mechanisms 13b of the liquid supply apparatus according to the third embodiment are provided instead of the first pump mechanism 13 and the second pump mechanism 13a. Also good.

  The displacement sensor 135 and the liquid leakage sensor 136 provided in the pump mechanism 13 are not limited to the structures described in the above embodiment, and may have various structures. For example, a float type liquid leakage sensor 136 may be used, and when electricity cannot be used to detect the liquid, such as when the conductivity of the liquid in the variable container is low, it is directed toward the bottom surface of the pressure resistant container. A structure may be adopted in which reflected light of the emitted light is received, and leakage is detected by a change in optical characteristics of the reflected light.

  The pressure loss tube 143 of the flow meter 14 is not necessarily made of resin, and may be formed of other materials. In this case, the pressure loss tube 143 is preferably formed of a material having high durability against various types of liquids. Further, the storage unit 145 and the calculation unit 146 of the flow meter 14 may be integrated into the feedback controller 151 of the control unit 15.

In the substrate processing apparatus 2 according to the fourth embodiment, instead of the liquid supply apparatus 1 having one variable container 131, a liquid supply apparatus 1a having two variable containers or a motor 138 is used as a drive source. In the substrate processing apparatus 2a according to the fifth embodiment, the liquid supply apparatus 1 or the third embodiment may be used instead of the liquid supply apparatus 1a. Such a liquid supply apparatus may be provided.

  In the substrate processing apparatus according to the fourth and fifth embodiments, a liquid other than pure water and hydrofluoric acid may be mixed to generate a processing liquid, and other processing than etching may be performed on the substrate 9. (For example, a cleaning process) may be performed.

It is a figure which shows the structure of the liquid supply apparatus which concerns on 1st Embodiment. It is a figure which expands and shows the vicinity of a variable container and a pressure vessel. It is a figure which expands and shows the vicinity of a variable container and a pressure vessel. It is a front view which shows the structure of a flowmeter. It is a top view which shows the structure of a flowmeter. It is a figure which shows the relationship between a differential pressure | voltage and a flow volume. It is a figure which shows the flow of the liquid supply by a liquid supply apparatus. It is a figure which shows the flow of the flow control by a liquid supply apparatus. It is a figure which shows the pump mechanism of a comparative example. It is a figure which shows the structure of the liquid supply apparatus which concerns on 2nd Embodiment. It is a figure which shows the flow of the liquid supply by a liquid supply apparatus. It is a figure which shows the flow of the liquid supply by a liquid supply apparatus. It is a figure which shows the mode of switching of operation | movement of a 1st pump mechanism and a 2nd pump mechanism. It is a figure which shows the flow of the flow control by a liquid supply apparatus. It is a figure which shows the change of a flow volume. It is a figure which shows the pump mechanism of the liquid supply apparatus which concerns on 3rd Embodiment. It is a figure which shows the substrate processing apparatus which concerns on 4th Embodiment. It is a figure which shows the substrate processing apparatus which concerns on 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Liquid supply apparatus 2,2a Substrate processing apparatus 9 Substrate 11 Flow path 12 Liquid supply source 13 (First) pump mechanism 13a Second pump mechanism 13b Pump mechanism 14 Flow meter 15 Control unit 21 First flow path 22 Second Flow path 25 Processing tank 26 Substrate holder 27 Nozzle 131 (First) Variable container 131a Second variable container 131b Variable container 132, 132a Pressure vessel 133, 133a Electropneumatic regulator 135 Displacement sensor 136 Leak sensor 137 Moving mechanism 138 Motor 141 First pressure gauge 142 Second pressure gauge 143 Pressure loss tube 1311, 1311a Bellows 1312 Upper end 1313 Lower end S11-S13, S21-S27, S31-S34, S41-S44, S121, S131-S134, S221 Step

Claims (17)

A liquid supply device for supplying a liquid,
A pump mechanism for delivering liquid to the flow path by reducing the volume by applying pressure to the deformable variable container;
A flowmeter that is disposed downstream of the pump mechanism and measures a flow rate of the liquid flowing through the flow path per unit time; and
Based on the flow rate of the liquid obtained by the flow meter, the flow rate of the liquid flowing through the flow path is set in advance as a flow rate when the liquid is sent to the flow path by compression of the variable container . A controller that provides an electric signal to the pump mechanism for controlling the pressure applied to the variable container so as to achieve a set flow rate;
With
The flow meter is
A circular pipe which is a pressure loss part provided as a part of the flow path;
A first pressure gauge that is disposed between the pump mechanism and the circular pipe and measures the pressure of the liquid flowing into the circular pipe;
A second pressure gauge that is disposed downstream of the circular pipe and measures the pressure of the liquid flowing out of the circular pipe;
A differential pressure type flow meter comprising:
The liquid supply device is characterized in that the flow rate of the liquid is measured by the flow meter while the liquid is being delivered to the flow path by one compression of the variable container. The liquid supply apparatus according to claim 1,
The liquid supply apparatus, wherein the variable container is made of resin. The liquid supply apparatus according to claim 1 or 2,
The liquid supply apparatus, wherein the variable container includes a bellows. The liquid supply device according to any one of claims 1 to 3,
The pump mechanism is
A pressure vessel containing the variable container therein;
An electropneumatic regulator that adjusts the pressure between the pressure vessel and the variable vessel;
A liquid supply apparatus comprising: The liquid supply apparatus according to claim 1 or 2,
The variable container comprises a bellows;
The pump mechanism is
A pressure vessel containing the variable container therein;
An electropneumatic regulator that adjusts the pressure between the pressure vessel and the variable vessel;
With
One end of the variable container is fixed to the pressure-resistant container, and the other end is a free end. The liquid supply device according to claim 5,
The liquid supply apparatus, wherein the pump mechanism further includes a displacement sensor that detects a displacement of the other end with respect to the pressure resistant container. The liquid supply device according to any one of claims 4 to 6,
The liquid supply device, wherein the pump mechanism further includes a liquid leakage sensor that detects leakage of the liquid from the variable container at a bottom portion inside the pressure resistant container. The liquid supply device according to any one of claims 1 to 3,
The pump mechanism is
A motor whose output torque can be controlled;
A pressurizing mechanism for applying pressure to the variable container by torque output from the motor;
A liquid supply apparatus comprising: A liquid supply apparatus according to any one of claims 1 to 8,
And further comprising another pump mechanism having the same structure as the pump mechanism,
By the control of the control unit, the compression of one of the variable container of the pump mechanism and the other variable container of the another pump mechanism, and the other extension in parallel with the compression of the variable container and the other variable container The liquid supply apparatus is alternately performed on another variable container. The liquid supply device according to claim 9,
2. The liquid supply apparatus according to claim 1, wherein before the compression of one of the variable container and the other variable container is stopped, the expansion of the other is stopped and the compression of the other is started. The liquid supply apparatus according to any one of claims 1 to 10,
In the circular pipe of the flow meter, the liquid flow having a Reynolds number of 2000 or less is formed. The liquid supply apparatus according to claim 11,
The liquid supply apparatus, wherein the circular pipe is made of resin. A substrate processing apparatus for processing a substrate,
A first flow path through which the first liquid flows;
A second flow path where the second liquid flows and merges with the first flow path;
The liquid supply device according to any one of claims 1 to 12, wherein the liquid supply device is provided on an upstream side of the second flow path and supplies the second liquid.
A process in which a processing liquid that is a mixed liquid of the first liquid and the second liquid is stored and the substrate is immersed while being positioned downstream of the confluence of the first flow path and the second flow path A tank,
A substrate processing apparatus comprising: A substrate processing apparatus for processing a substrate,
A substrate holder for holding the substrate;
A first flow path through which the first liquid flows;
A second flow path where the second liquid flows and merges with the first flow path;
The liquid supply device according to any one of claims 1 to 12, wherein the liquid supply device is provided on an upstream side of the second flow path and supplies the second liquid.
A processing liquid supply unit that is located downstream of the confluence of the first flow path and the second flow path and supplies a processing liquid that is a mixed liquid of the first liquid and the second liquid to the substrate. When,
A substrate processing apparatus comprising: A liquid supply method for supplying a liquid, comprising:
a) expanding the deformable variable container in the pump mechanism to increase the volume, and storing the liquid from the liquid supply source in the variable container;
b) delivering the liquid to the flow path by applying pressure to the variable container to reduce the volume;
With
Step b)
b1) a step of measuring a flow rate per unit time of the liquid flowing through the flow path by a flow meter disposed on the downstream side of the pump mechanism;
b2) Based on the flow rate measured in the step b1), the flow rate of the liquid flowing through the flow path is preset as a flow rate when the liquid is sent to the flow path by compression of the variable container . Controlling the pressure applied to the variable container to a set flow rate;
With
The flow meter is
A circular pipe which is a pressure loss part provided as a part of the flow path;
A first pressure gauge that is disposed between the pump mechanism and the circular pipe and measures the pressure of the liquid flowing into the circular pipe;
A second pressure gauge that is disposed downstream of the circular pipe and measures the pressure of the liquid flowing out of the circular pipe;
A differential pressure type flow meter comprising:
The liquid supply method, wherein the flow rate of the liquid is measured by the flow meter while the liquid is being delivered to the flow path by one compression of the variable container. The liquid supply method according to claim 15, comprising:
c) expanding another variable container deformable in another pump mechanism to increase the volume and storing the liquid from the liquid source in the other variable container;
d) delivering the liquid to the flow path by applying pressure to the other variable container to reduce its volume;
With
Step d)
d1) measuring the flow rate per unit time of the liquid flowing through the flow path by the flow meter on the downstream side of the other pump mechanism;
d2) controlling the pressure applied to the other variable container based on the flow rate measured in the step d1) so that the flow rate of the liquid flowing through the flow path becomes the set flow rate;
With
The liquid supply method, wherein the step a) and the step d) performed in parallel and the step b) and the step c) performed in parallel are alternately performed. The liquid supply method according to claim 16, comprising:
The fixed time after the start of the step b) and the fixed time before the end of the step b) overlap with the fixed time before the end of the step d) and the fixed time after the start of the step d), respectively. A liquid supply method.

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