Liquid flow controller and precision dispense apparatus and system

Liquid flow controllers and precision dispensing equipment and systems

The present invention is related to the "Fluid Flow Measuring and Proportional Fluid Flow Control Device" of US Patent Application No. 60/397,162 and approved US Patent No. 6,348,098 on February 19 .19 US application No. 60/397,053 "Liquid Flow Controller and Precision Dispense Apparatus and System" claims priority.

In the manufacture of semiconductors, such as deionized water, photoresist, spin on dielectrics (spin on dielectrics), spin on glass (spin on glass), polyimide, developer, chemical mechanical polishing (CMP) slurry...etc. various fluids must be accurately distributed and deposited on the coagulated substrate. For example, in a conventional device, the wafer to be processed is placed under a suitable nozzle, and then a predetermined amount of liquid or slurry is sprayed on the wafer by the nozzle to coat or process the wafer. The predetermined amount is not only based on the absolute amount or mass of the liquid deposited on the wafer, but also depends on the number of pump cycles, pipe diameter, or other characteristics of the fluid surrounding environment. Typically, the wafer is then rotated so that the deposited liquid is completely distributed across the surface of the wafer. It is immediately clear that the distribution ratio and the amount of liquid deposited have reached the critical point, which can easily cause problems.

When the fluid flowing through the nozzle stops, for example, between two wafer processing processes, there is a pressure difference (potential) on the nozzle, so droplets are formed and drop on the wafer below the nozzle superior. At this time, if the pattern formed on the wafer is destroyed, the wafer must be reprocessed or discarded. In order to prevent the formation of harmful droplets on the nozzle, a suction or stop/suction valve is generally used. The latter valve is typically a pair of dual pneumatic control valves. One valve is used to stop the liquid flowing to the nozzle, and the other valve is used to suck back the liquid at the dispensing end or outlet of the nozzle. This method can not only help prevent the formation and dripping of liquid droplets at the nozzle mouth, but also help prevent the exposed surface of the liquid from drying out, and avoid the clogging of the nozzle and reduce the fluid content of the outlet.

There is also a problem with the coating of large wafers (for example, 300mm or more in diameter), because turbulence is generated. Traditionally, the rotational speed of the wafer is used to diffuse the coating fluid applied to its center radially outward to the edge of the wafer. However, this method will cause turbulent airflow on the entire surface of the chip, causing the coating to not be flat and uniform. Although the rotation speed of large chips can be reduced to reduce the turbulence on the surface of the chips, this creates new problems. If this speed is reduced, the flow rate of the fluid on the wafer surface will slow down, that is, it is possible that the fluid may stop or become dry before reaching the edge of the wafer.

In semiconductor manufacturing, a pump is traditionally used to apply liquid. However, the applicable pumps are extremely expensive and must be replaced frequently due to excessive wear. In addition, the footprint of this type of pump may be too large and needs to be corrected to make it suitable. Although it is not available for all, it can be used for most applications.

Liquid flow controllers containing differential pressure measurement, such as NT6500 (produced by Entegris Corp. Chaska, MN) can be used, but this type of controller cannot be applied to a wide range of different flow rates and/or different viscosities. Therefore, I hope to provide a solution that can easily adjust the pressure drop.

Therefore, Nai wants to provide a flow measurement and supply (dispense, or distribution, application, etc.) system that can accurately and repeatedly supply flow without the above-mentioned shortcomings. In addition, the present invention also provides precise control of the desired or required liquid flow rate.

Furthermore, it is even more desirable to provide a pump-less system that can be used to provide accurate and repetitive fluid supply.

In addition, Yuxi provides a pneumatic proportional flow valve, which is linear or substantially linear, has the smallest pressure drop, and has little or no hysteresis.

The present invention can solve the aforementioned problems. According to the present invention, a device and a control system are included to monitor (preferably digital) and/or control the pressure applied to a pneumatic load such as a proportional fluid control valve. The measurement input of the fluid measuring device that responds to the flow rate. With this liquid measurement input, the pressure applied to the pneumatic load can be controlled, and the pneumatic load can be increased or decreased (proportional opening or closing of the pneumatic valve) to change the flow rate of the fluid For the value of hope. In addition, the pneumatic load can also be adjusted in response to changes in fluid temperature and viscosity (proportional opening or closing of the pneumatic valve).

The embodiments of the present invention provide a fluid measurement device, which can generate a flow measurement signal based on the pressure drop caused by a friction type flow element in which the fluid communicates with a proportional fluid control valve and straddles it. The fluid pressure can be measured at or near the outlet of the friction flow element, and at or near the outlet, the measured signal can be amplified, and the resulting pressure drop can be converted into the flow output of the fluid. And can be controlled. The flow output can be sent to a controller to adjust the flow of one or more valves to the desired value.

The present invention also provides a control system applicable to various fluids, and applicable to fluids of various viscosities. And it can perform precise and repetitive flow control and supply performance in a low-cost and flexible way. Moreover, it can also quickly respond to changes in the process at any time and minimize the difficulty of operation.

The present invention also relates to a proportional fluid control valve. By using the fluid controller and motor pumping system of this valve, the linearity can be improved and the hysteresis can be reduced. This valve can make the fluid flow smoothly and steadily. The flow is essentially linear, and the fluid has very little turbulence. The valve is preferably pneumatic. This valve does not generate temperature, and the valve can be operated by any suitable device, including stepping motors, linear motors, voice coils or other force actuators.

The present invention also relates to an auxiliary input module. The upstream flow system is connected to a flow measuring device. The flow measuring device is arranged in the motor pump system and can be used to adjust the flow before entering the flow measuring device. Of fluids. This module can be filled from a pressureless source such as a barrel. This module can also be compensated by a pressure feed line (machine room feed or a pressure cylinder) for improper or excessive fluid pressure. This module can defoam the fluid used in the system.

The present invention also provides a motorless pump system, which can be applied to various fluids and feed sources. Therefore, in the manufacture of semiconductors, most liquid supply points can be standardized and consumers can be modularized. Configuration of other features, such as filtering and temperature control.

The present invention also provides a general-purpose molded valve body. Compared with mechanical valve bodies, the valve body of the present invention requires only a few components. In one embodiment, the molded valve body is specially designed for flow control, and contains two sensor housings with precisely positioned flow passages to make the most appropriate use of the space. One or more sensor housings can be formed separately and used as inserts, which can be installed in various positions. Pneumatic and mechanical components are installed in the opposite end of the valve cavity, the differential pressure of the system can be reversed, and the differential pressure upstream of the valve can be recorded to monitor the supply pressure.

An embodiment of the present invention may include a set of computer-readable instructions stored on a computer memory and executable by one or more processors, and the set of computer-readable instructions may be executed to receive an upstream pressure signal; Receive a downstream pressure signal; calculate an error signal; and calculate a valve control signal based on the upstream pressure signal, downstream pressure signal, and error signal; and other instructions.

According to another embodiment of the present invention, the device includes a set of computer-readable instructions stored on a computer-readable memory and executable by one or more processors. The set of computer-readable instructions includes An upstream pressure signal; receiving a downstream pressure signal; and determining the valve gain for a specific valve based on the valve gain curve of the corresponding valve, wherein the change of the valve gain is determined by the position of the specific valve; and based on Calculate a valve control signal with upstream pressure signal, downstream pressure signal, error signal, and valve gain; etc. commands.

In another embodiment of the present invention, the device includes a set of instructions stored on a computer-readable memory that can be executed by one or more processors, and the set of computer-readable instructions includes instructions that can be executed to receive an upstream pressure signal ; Receive a downstream pressure signal; calculate the error signal based on the ratio, integral, and derivative of the upstream pressure signal and the downstream pressure signal; add an error gain to the error signal; based on the valve gain curve of the corresponding valve Determine the valve gain for a specific valve, where the valve gain changes according to the position of the specific valve; calculate a valve control signal based on the upstream pressure signal, downstream pressure signal, error signal, and valve gain; and based on a set Adjust the valve control signal appropriately for the value of the past position; wait for instructions.

First, as shown in Figure 1, it is a block diagram of a fluid flow (quantity) controller according to a representative embodiment of the present invention. A fluid control device, such as a fluid control valve 10 operated by air pressure, a circuit 12 with a fluid inlet and a circuit 13 with a fluid outlet, for supplying liquid to use points such as substrates, wafers (not shown), etc. . The fluid outlet line 13 is in fluid communication with a friction type flow element 15, so all the fluid existing in the fluid control valve 10 can enter the friction type flow element 15. For example, the first pressure sensor 24, which is one of the pressure transducers, can be integrated with the fluid control valve 10 and is located at or near the entrance of the friction flow element 15 (for example, at or near the exit of the fluid control valve 10) , To sense a first pressure, and a second pressure sensor 25, such as a pressure transducer, is arranged at or near the outlet of the friction flow element 15 to sense a second pressure. In addition, a single pressure difference sensing device can also be used. The fluid contact part of the pressure sensor is preferably made of an inert material (depending on the fluid used), such as sapphire, or a coating material, such as Perfluoropolymer, is applied to prevent direct contact with the fluid. The details of the appropriate pressure sensor are illustrated in Figure 7. Therefore, the housing 60 has a fluid inlet 61 and a fluid outlet 62 separated from the inlet 61. Pressure and temperature sensor 64 is based on Perfluoroelastomer The O-ring is sealed in the housing 60. The end cap 65 is coupled to the housing 60 by a plurality of stainless steel bolts or tips 66 as shown, for example. The sensor 64 senses the pressure and temperature of the liquid in the fluid flow path between the inlet 61 and the outlet 62, and sends the sensed pressure and temperature signals to the controller.

Returning to Figure 1, a pneumatic proportional control valve, such as a solenoid valve, is pneumatically connected to the fluid control valve 10. Each pressure sensor 24, 25 (or a single pressure difference sensing device) is connected to, for example, a computer processor or control circuit 30 with proportional, integral, and lead (PID) feedback components. Since the sensors 24 and 25 sample the pressure and temperature of each fluid circuit, the sampled data is sent to the controller 30. The controller 30 compares the sent values, and calculates the pressure difference across the friction flow element 15, the details will be described below. A signal from the controller 30 based on the pressure drop is sent to the pneumatic proportional control valve 20 to adjust the fluid control valve 10, preferably after compensating for temperature, and/or viscosity and/or density.

Particularly, this system is best to use an appropriate fluid, such as deionized water, or isopropyl alcohol, as a fluid standard for calibration. For example, once the system is calibrated towards the standard, the characteristics of the fluid to be supplied, such as viscosity and density, can be automatically input or determined. If so, the fluid to be supplied can be compared with the standard and established between them relation. Based on this relationship, the measured pressure drop across the friction flow element (selected for calibration of temperature, viscosity, etc.) is compared to the flow rate associated with the desired or target flow rate, and the fluid control valve 10 is It is adjusted by a pneumatic proportional control valve 20.

The suction valve 21, which is one of independence, is preferably a user-programmable proportional valve that communicates with a proportional control valve such as a solenoid valve (which may be the same as or different from the pneumatic proportional control valve 10). And use a controller (or a different controller) for control. When the fluid supply is stopped or circulated, the suction valve is activated. When the fluid supply is interrupted, the droplets can be reduced or prevented from falling on the wafer, and the liquid can be sucked back from the supply nozzle. Reduce or prevent fluid exposure to the atmosphere. The rate or extent of the opening or closing of the suction valve is controlled by the controller. The suction valve 21 is preferably provided downstream of the fluid control valve 10.

By controlling the pressure applied to the fluid control valve 10 and/or the suction valve 21, the supply parameters of various fluids can be controlled. For example, when the supplied fluid is a low-viscosity liquid, the pressure can be used to precisely adjust the liquid control valve 10 to ensure a uniform supply of the liquid. Similarly, since the flow rate of the fluid discharge point is sucked back by the suction valve 31 according to a ratio, the flow rate of the fluid can be controlled. Once the pressure-volume relationship of the specific fluid control valve 10 used is characterized, the system of the present invention can obtain unrestricted flexibility. It is true that the supply pressure is a good indicator of the supply quality (such as uniformity), but for all applications, there is no "ideal" supply pressure type, and in all liquid control, this kind of ideal Sexual pressure cannot be the same before and after. In the control system of the present invention, once the characteristics of the fluid control valve are known, the process engineer can adjust the fluid supply pressure to achieve the "ideal type" used in the specific process.

Figures 8A to 8E show a one-piece fluid control valve 10 and sensor assembly according to a representative embodiment of the present invention. This valve is essentially linear, which means that when the operating pressure acting on the diaphragm increases, the flow rate of the fluid decreases. In addition, the hysteresis of this valve is very small. Preferably, the pressure (and temperature) sensors are all located in the fluid stream, and the housing 60 is preferably formed integrally with the main housing 70 of the valve (therefore, the pressure and temperature of the fluid can be sensed). This is before the inlet of the friction flow element.

Especially as shown in Figures 8B, 8C, 8D and 8E, the valve top end cap 71 contains two concentric circular ring sleeves 84, 85, between which a circular groove can be defined to accommodate one of the pneumatic rings 74. Synthetic rubber O The ring 72 is used to seal the valve pneumatic diaphragm 73 in the housing. The opposite threaded buckle 76 is used to sandwich the valve upper diaphragm 77 and the valve bottom diaphragm 78, and is biased by the spring 80. The internal assembly is held together with the threaded buckle 76 screwed on the stainless steel bolt 75, and the external assembly is held together with the valve bottom end cap 82, stainless steel pin or bolt 83, and the valve upper end cap 71 Wait to hold together. The one connected to the upper end cap 70 of the valve is a push-in connection type component, which is used to achieve a pneumatic connection with a pneumatic proportional control valve 20 with appropriate piping or the like. The flow path (between the inlet and the outlet) in the fluid control valve 10 is not in-line, so the pressure drop and the unscrewable volume can be further reduced, as illustrated in Figures 7A to 7D. The off-position flow path of the valve inlet and outlet is easy to make the thick material or other fluid flow smoothly, and can minimize the accumulation.

The fluid enters the valve inlet 12 and flows in the linear flow path 12A until it reaches the circular cavity 90 through the inlet hole 99. The fluid tends to swirl in the cavity 90, and then, in accordance with the action of the applied air pressure, the valve is opened, and the flow is flowing, passing the diaphragm 77, 78 into the narrow circular channel 92 and entering the cavity 89. A swirling fluid flow path can be created in the cavity 89 toward the outlet (via the outlet hole 85) through the linear path 13A. In order to reduce the pressure loss between the cavities 89 and 90, and to maximize the effect of the swirling effect of the fluid in the device, the sealing surface of the valve can be provided with a radiused or chamfered shoulder 93 (E.g. 0.04 inch). The fluid inlet path 12A and the fluid outlet path 13A are preferably arranged along the tangent direction of the cavities 89 and 90 (preferably more than the central axis), which contributes to the uniformity of fluid flow and reduces pressure drop and accumulation.

By controlling the pressure entering the push-and-communicating linear component 86, the amount of air pressure that deforms the valve diaphragm 73 can be controlled. The greater the pressure in the pneumatic cavity 88, the greater the deformation of the pneumatic diaphragm 73. Pushing the valve button 76 connected to the top will deform the diaphragms 77 and 78 and compress the spring 80, and the diaphragm 78 will be from the valve seat or part of it. The shoulder 93 used to define the passage 92 (Figure 8D) is removed from the position to open the valve. Especially, it is the design of the valve. The elastic force of the spring 80 and the air pressure are counted against each other. The spring 80 is used to push all the diaphragms so that the bottom diaphragm 78 is seated on the shoulder 93 to seal the main valve body. When the air pressure is introduced, the opposing spring 80 is set. Once enough air pressure is applied, the spring cannot keep the valve closed. The compression of the spring causes the diaphragms to deform in the direction of the compressed spring, and the valve can be opened. The greater the air pressure, the greater the compression of the spring 80 and the greater the opening of the valve.

In addition to the selection of suction, the closing speed of the fluid control valve can also effectively control the height of the fluid at the discharge end or outlet of the nozzle, and in any situation, a suction valve can be completely replaced. The valve is designed with two fluid diaphragms, so it is possible. When the valve is closed, the air pressure is released in the pneumatic cavity, and the spring forces the fluid diaphragm 78 (Figure 8D) at the bottom of the valve to engage the valve seat. Due to the connection of the fluid valve membrane 78, the other fluid membrane 77 is bent outward and toward the pneumatic cavity. This kind of displacement can result in a smaller suction effect.

The controller can include an inert feature that can significantly reduce the difference in response time from valve to valve. Depending on the opening pressure requirement for a given valve, the inert pressure can be adjusted so that the reaction time from unit to unit tends to be equal. When the valve is not actuated to generate fluid flow, the inert pressure is provided to the pressure of the air cavity. Therefore, if a specific valve must be opened at 40 psi and another specific valve must be opened at 30 psi, the inert air pressure can be set to 15 psi and 5 psi respectively. As a result, the amount of time is almost the same. The inertness of the valve can also enable the system to be used for system exhaust with very few set requirements. The valve can be kept open to minimize exhaust, preferably nitrogen, and vent from a pneumatic proportional control valve, so as to have a safe exhaust inside the closed system, especially when the system is equipped with electronics The component is so.

FIG. 30 is a block diagram of an embodiment of a controller 2700. This controller can generate a valve driving signal for constricting/opening the pneumatic proportional control valve 20. The controller 2700 may include a power supply 2702, a management processor 2704, a pressure circuit 2705, an auxiliary function circuit 2706, a control valve driver 2708, a suction valve driver 2709, a corresponding interface 2710, and an input/ The output circuit 2711 and a control processor 2712. The control processor 2712 may include a flash memory that can store a set of computer-readable instructions 2716, which are executed based on the pressure signal received from the pressure circuit (as illustrated in Figure 6) to generate a Valve control signal. Various components of the controller 2700 can be connected via the data bus 2718. Note here that when the computer-readable command 2716 is software in a single computer, the computer-readable command can be implemented in accordance with software, firmware, hardware commands, or other conventional appropriate programs. In addition, , Each instruction can be dispersed in multiple memories, and can be executed by multiple processors.

During operation, the power supply 2702 supplies power to various components of the controller 2700. The pressure circuit 2705 can read the pressure from the upstream and downstream pressure sensors, and provide upstream and downstream pressure signals to control the control processor 2712. The controller processor 2712 can calculate a valve control signal based on the pressure signal received from the pressure circuit 2705, and in turn, can generate a valve drive signal based on the valve control signal. The valve control signal can be generated according to the method shown in Figure 6 below. This method can be based on software, or stored in a computer-readable memory (such as RAM, ROM, FLASH, magnetic storage or other conventional computer-readable memory), and it can be used by other computers that can be accessed by the control processor 2702. Read the command to do it.

Regarding other components of the controller 2700, the managed processor 2704 can be a general-purpose processor that can perform various functions as known in the art, including connection with other devices, or any other programmable functions. An example of a general-purpose processor can be a Motorola 8051 processor. The auxiliary function circuit 2706 can be used as an interface with other devices. The suction valve driver 2709 can control a suction valve (for example, the suction valve 21 in Figure 1). The commensurate interface 2710 and input/output circuit 2711 can provide various devices for connecting data to the controller 2700. Other components may include a monitoring unit 2720, which can be used to monitor various functions of the system, such as various eeprom memories or other memories, expandable ports or other conventional computer components, etc., as is known in the art.

FIG. 31 is a block diagram of a representative example of the control logic circuit of the controller 2700. The controller can generate a valve driving signal to constrict/open the proportional control valve 20. Several components illustrated in the controller 2700 include a control processor 2712, a corresponding interface 2710, and a monitoring unit 2710. In addition, an expansion port 2802 is shown. The expansion port 2802 can be used to attach a plurality of daughter boards to expand the functions of the controller 2700.

In the embodiment of FIG. 31, the functions of the management processor 2704 are divided into three items: the processing part, the memory device part 2808, and the dual-port RAM part 2810. The memory device portion 2808 may include various types of memory, such as flash memory, RAM, EE, and other conventional computer-readable memory. If the management processor 2704 is equipped with a flash memory, its advantage is that it can easily download the latest firmware information through, for example, a commensurate interface 2710. In addition, the memory device portion 2808 may also include functions such as chip selection and address decoding. It should be noted that each of the memory unit 2808, dual-port RAM memory unit 2810, and processing unit 2806, etc., can be provided in a single processor.

The control processor 2712 may include a flash memory 2714 that can store a set of computer-readable instructions 2716, and execute the set of instructions to generate a valve control signal based on the pressure signal received from the pressure circuit, as shown in Figure 6 instruction. The control processor 2712 and the processing unit 2808 of the management processor, in one embodiment of the present invention, can share data by accessing each other to the dual-port RAM unit 2810. The control processor 2712 and the processing unit 2808 of the management processor can be driven by a single system clock 2812 (for example, a 20 MHz clock) or different system clocks.

Figure 32 shows an embodiment of the pressure control circuit 2705. The pressure control circuit 2705 may include an upstream pressure input 2902 and a downstream pressure input 2904, respectively from the upstream and downstream pressure sensors. The input upstream and downstream signals can be amplified and filtered before being converted into digital signals by A/D converters 2905 and 2906. As shown in Fig. 29, the pressure control circuit 2704 can also generate a differential pressure signal that can be converted into a digital signal using the A/D converter 2908. The pressure control circuit can be calibrated by the calibration circuit 2910. The calibration circuit can include hardware and/or software. Based on the known pressure applied to the pressure sensor, any changes in the pressure results read on the sensor can be compensated for .

In addition, the pressure control circuit 2704 can be used to receive upstream and downstream input temperature signals (for example, at the input points 2920 and 2922), and the A/D converter can convert the temperature signals into digital signals. One or two pressure sensors 24, 25 (or differential pressure sensors), each can include a temperature sensing device, which can be located at each position (for example, at or near the entrance or exit of the friction flow element) The temperature of the fluid is sensed, and the temperature signal is provided to the input points 2920 and 2922. In addition, the temperature sensor can be installed separately from the pressure sensor. The various temperatures sensed are connected to the controller, and the controller calculates an appropriate fluid flow correction value, and sends a signal to the pneumatic proportional valve 20 based on the calculation for correcting various temperature changes. Because the pressure sensor itself generates heat and is absorbed by the fluid, and can realize the flow characteristics of the fluid in the system, the above actions are indeed feasible; the regional temperature change on the surface of the sensor can change the output of the sensor. Other embodiments of the invention can correct for temperature errors based on, for example, a voltage drop across a constant current device (such as the pressure sensor itself).

Figure 4 shows another embodiment of the pressure control device 2705. As shown in the schematic diagram in Figure 4, the pressure sensors 24, 25 preferably use two instrumented amplifiers: one for upstream pressure and the other for downstream pressure. Using digital gain and offset control, each sensor can be corrected automatically or manually. These two analog signals can be converted into digital signals by an analog/digital (A/D) converter, and the differential pressure can be derived in the software only by subtracting the value. The shortcomings of this technology are the degradation of resolution and the common mode.

The analog/digital converter must convert each signal and mathematically remove the common mode. A feasible method is to increase the analytical capability of the A/D converter to obtain the required differential pressure. For example, when the downstream pressure is 15psi and the differential pressure used for this flow is 0.1psi, it is converted to 5.00Vdc (15psi=2.50Vdc), and each transducer must be capable of measuring peak pressure (30psi) or more. Since 15.1psi is 2.517Vdc, the differential pressure signal is 0.017Vdc (outside of 5.00Vdc).

When the third amplifier is electrically connected to each A/D converter, the common mode can be eliminated, so that each A/D converter only needs to analyze the maximum differential pressure. If so, the common mode is It is greatly reduced. Therefore, the total differential pressure in the above example is equal to 5psi, which is transformed into a voltage of 5.00Vdc. In this way, the resolution can be increased by 6 times (6X).

The gain of differential pressure (differential pressure) amplification can also be increased to further increase the resolution of differential pressure signals. A single differential pressure sensor can also be used, but in one embodiment, separate signals of upstream and downstream pressure cannot be detected.

Preferably, the upstream and downstream pressures also include A/D converters. Then these separate pressures can be used to monitor the upstream and downstream pressures, and can be used to determine process changes (such as replacing the filter). These pressures can also be used separately for single pressure control, which can be used for viscosity calculation.

Fig. 6 is an embodiment of a flow chart for the adjustment of the flow control valve 10 and a control algorithm. Use a controller (such as the controller 30 shown in Figure 1) to execute a set stored in a computer readable memory (such as RAM, ROM, magnetic memory device, or any other conventional computer readable memory) This kind of algorithm can be realized by the computer-readable instructions, and the algorithm can also include technology to reduce fuzzy logic and components from a matching controller. Therefore, the controller is a linear control system based on dynamic mode. If you want, you can use matching control or smart control to achieve greater accuracy. The matching control can use a non-linear optimal controller (Optimizer) to improve the overall action of the control system, and it is a known one. Figure 27 shows an embodiment of a controller.

As shown in the controller process shown in Figure 6, in step 902, the upstream and downstream pressure signals from the upstream and downstream pressure sensors via the A/D converters (such as A/D converters 2905 and 2906) can be read. At this point, the upstream and downstream signals can be voltage-sampled (ie, digitally sampled) to represent the analog voltage generated by the pressure sensor. In step 904, the controller can also read a temperature based on the reading of a temperature sensor, or calculate a temperature based on the current flowing through a sensor, and can also use any known temperature correction algorithm to correct the temperature. The upstream and downstream pressure signals of the temperature. In step 906, the controller can filter the upstream and downstream pressure signals, and in step 908, the pressure signal is converted into a pressure value, which can be stored in the memory (step 909).

In steps 910 and 911 of the controller, the integral value, derivative value and any correction value for the upstream and downstream pressure can be calculated. The calculation of integral value and derivative value can be carried out by using various methods known in the art. The controller can also calculate (step 912) and store (step 914) the differential pressure between the upstream and downstream pressures. At step 916, the controller may calculate an error (error) signal based on the derivative and integral values for the upstream and downstream pressures, and at step 918, the error value may be stored. According to an embodiment of the present invention, in step 920, an error gain can be added to an error signal, which helps to compensate for the low signal value when the pressure is low.

At step 922, the controller can read the gain of the valve. Figure 5 is a graph of the valve gain of an embodiment. This curve adjusts the gain of the signal applied to the valve to reach the current position proportionally. The gain curve achieved by software can make corrections to the changes from valve to valve in the system. In addition to correcting the changes of specific valves, the valve gain curve can also be used to compensate for overshoot and response time. In Figure 5, the valve gain curve is used for two valves, where valve A is line 500 and valve B is line 501. The curve (or valve level) used for each valve can be created based on experience and can also be stored in the memory of the controller. The curve can adjust the gain of the valve control signal based on the current valve position.

In the graph of Figure 5, the X-axis represents the valve position, and the Y-axis represents the gain. In an embodiment of the present invention, each curve is made using 4 points: maximum gain, minimum gain, tilt starting point, and tilt ending point. The maximum gain typically starts from the position where the valve is not operating and reaches the tilt starting position. The minimum gain starts at the tilt end position and ends at the 100% point of the valve stroke. The actual slope (slope) in the gain decreases linearly from the start point of the slope to the end point of the slope. The controller can read the valve gain curve for each valve and adjust the valve control signal accordingly. For example, when the valve position is between lines 502 and 504, in step 922, the controller can read the valve curve and adjust the value used for the control signal to count as a high gain. When valve A is located between lines 502 and 504, the curve can keep the gain of the valve signal at a high level to overcome the force that keeps the valve closed. At the point where the valve is actually open, the controller can adjust the control signal based on the valve gain curve and valve position to reduce the gain count. The controller can adjust the valve control signal along the valve gain curve to count the valve gain at any point. It should be noted here that the valve gain curve shown in Figure 5 is only a representative example. The controller can be based on any valve gain curve stored in any computer readable memory and accessible by the controller. To adjust the control signal of the valve.

In step 924, based on the error signal and the pressure value, a control signal can be generated and written into a digital/analog (A/D) converter (such as a control valve driver). The A/D converter can generate an analog valve drive signal to drive a valve. Embodiments of the present invention may include a valve integration step (e.g., step 926) to delay the valve control signal, and a matching adjustment step (e.g., step 928). The matching adjustment step can read the pre-defined number and the stored previous position value to adjust the current valve control signal.

In addition, the controller may also implement the monitoring step 930, which may be part of the matching adjustment. This function allows real-time editing of data such as set-point overshoot, settling time, tilt stability and percentage error. During the setting mode, the edited data is analyzed by the controller, and it can adjust the control value to the most appropriate performance (that is, the matching adjustment step 928 is performed).

It should be noted here that the controller can also adjust the valve control signal to compensate for the change in viscosity. Because the viscosity of the fluid changes the Δp test value at the same flow rate, it must be corrected. One method of calibration compares the current Δp and flow rate with the Δp and flow rate of isopropyl or water as a standard. After that, the user can enter the difference between them. Another method is to measure internal parameters and compare them with preset similar parameters, and make internal compensation. The third method is to use curves that have been created in the factory and used for various fluids. The controller can store a variety of curves, and the user can make a variety of choices.

Many different parameters covering a wide variety of applications can be set to ensure proper operation of the suction valve. For example, the "off time" of the suction valve can be used to adjust the time for the pressure change from ON to OFF. This is the time to move the valve diaphragm from its fully extended position to the suction position. If the moving speed is too fast, it may cause the streamer to pull the bubbles into the streamer or cavity. Suction valve "action time" (on time) can be used to adjust the pressure change time from OFF to ON. This is the time required to move the end of the valve diaphragm from the suction position to the fully extended position. When this kind of movement is too fast, it may cause the "bulge" of the streamer (buldge), and it is harmful to change the actual supply. There are two other settings: suction back ON and OFF pressure settings. These two adjustments determine the distance that the valve opens to achieve the desired amount of suction. The greater the difference in this pressure, the greater the amount of suction. There are two reasons for using both ON pressure and OFF pressure: to adapt to the differences of similar types but different valve parts; and to adjust the nonlinearity of different valve parts and other system configurations. This entire action can also be delayed to separate the stop action and the suction action of the control valve. In some applications, the suction valve can be used to assist the control valve to stop the fluid. The method is shown in Figure 29, which is achieved by a separate suckback position when the fluid is stopped. . This auxiliary function can also be programmed as a percentage value of the stop action loaded at the beginning of the stop action or at the end of the stop action. If it has been programmed, the normal suction position can be used for suction after the delay. Turning back to Figure 2, the housing 100 shown contains various components of the present invention. Preferably, electrical components such as the LED board 105 and the main printed circuit board 106, as well as the pneumatic proportional valve manifold 110 such as the friction flow element 15, the fluid control valve 10, etc., are isolated from the fluid. The fluid enters the main fluid control valve 10 at a fluid inlet (not shown). After that, the fluid flows through the valve and enters the friction type flow element 15. In the illustrated embodiment, the flow element 15 contains a relatively short straight portion 15B. After that, the fluid is wound in a spiral shape until it reaches another equivalent. The long straight portion 15A ends, and the longer straight portion 15A can generate a second pressure (and temperature) sensing. The friction-type flow element 15 can be a tube, a duct, or two parallel hollow fiber tubes with a wrapping space, all of which have a sufficient size, so that when fluid flows in between, it can cause a pressure drop. Other suitable friction-type flow elements include, for example, serpentine-shaped channels made in the form of bulk polymeric materials, porous membranes, sinters, and filters. It is best to avoid a 90-degree turn for friction flow elements, otherwise it will increase blockage or cause excessive turbulence due to shear force. Although the friction type flow element 15 can be a linear type, the friction type flow element 15 is preferably made of a spiral coil type to save space, and its diameter and length depend on the flow rate. Therefore, the diameter and length of the friction flow element 15 are functions of the required pressure drop, so "noise" It can be ignored. As far as the given fluid is concerned, there are no conditions regarding the length of the pipe and the system. The smaller the diameter of the pipe, the greater the pressure drop. As far as the shape of the pipe is given, the viscosity of the fluid increases and the pressure drop will also decrease. Increase. For example, when a fluid control valve 10 is used to supply deionized water, the frictional flow element 15 is a 1/4-inch tube with an outer diameter, a wall thickness of about 0.047 inches, and a tube length of about 40 inches. The flow rate is about 2 liters per minute, but it also depends on the system conditions, such as the pressure of the supplied fluid, the supplied air pressure, and the system pressure difference outside the device. Simply changing the geometric shape of the friction flow element can make the flow rate for a given supply/flow condition reach the best condition. In order to reduce or reduce the flow of fluid outside the element 15, the inner diameter of the friction flow element is preferably the same or substantially the same as the inner diameter of the downstream flow path of the pipe or other element 15. The fluid flowing through the friction flow element 15 may be laminar flow or turbulent flow. Therefore, the fluid path is: fluid enters the fluid inlet of the fluid control valve 10, the flow path valve (and passes through the pressure and temperature sensors), enters the inlet of the friction flow element 15, passes through the friction flow element 15, and is sent out at its outlet (And passing through the pressure and temperature sensors located upstream and downstream of the outlet of the friction flow element 15). The elasticity of the present invention, according to an embodiment of the present invention, is that the friction-type flow element can be easily interchangeable based on, for example, flow characteristics and/or fluid characteristics. When the tube is 047 inches long and the pipe length is about 40 inches, the maximum flow rate that can be generated is about 2 liters per minute, but it also depends on the system conditions, such as the pressure of the supplied fluid, the supplied air pressure, and the system pressure difference outside the device. Simply changing the geometry of the friction flow element can make the flow rate for a given supply/flow condition reach the best condition. In order to reduce or reduce the flow of fluid outside the element 15, the inner diameter of the friction flow element is preferably the same or substantially the same as the inner diameter of the downstream flow path of the pipe or other element 15. The fluid flowing through the friction flow element 15 may be laminar flow or turbulent flow. Therefore, the fluid path is: fluid enters the fluid inlet of the fluid control valve 10, the flow path valve (and passes through the pressure and temperature sensors), enters the inlet of the friction flow element 15, passes through the friction flow element 15, and is sent out at its outlet (And passing through the pressure and temperature sensors located upstream and downstream of the outlet of the friction flow element 15). The elasticity of the present invention, according to an embodiment of the present invention, is that the friction-type flow element can be easily interchangeable based on, for example, flow characteristics and/or fluid characteristics. When the tube is 047 inches long and the pipe length is about 40 inches, the maximum flow rate that can be generated is about 2 liters per minute, but it also depends on the system conditions, such as the pressure of the supplied fluid, the supplied air pressure, and the system pressure difference outside the device. Simply changing the geometric shape of the friction flow element can make the flow rate for a given supply/flow condition reach the best condition. In order to reduce or reduce the flow of fluid outside the element 15, the inner diameter of the friction flow element is preferably the same or substantially the same as the inner diameter of the downstream flow path of the pipe or other element 15. The fluid flowing through the friction flow element 15 may be laminar flow or turbulent flow. Therefore, the fluid path is: fluid enters the fluid inlet of the fluid control valve 10, the flow path valve (and passes through the pressure and temperature sensors), enters the inlet of the friction flow element 15, passes through the friction flow element 15, and is sent out at its outlet (And passing through the pressure and temperature sensors located upstream and downstream of the outlet of the friction flow element 15). The elasticity of the present invention, according to an embodiment of the present invention, is that the friction-type flow element can be easily interchangeable based on, for example, flow characteristics and/or fluid characteristics.

Other types of devices used to generate pressure drop may be suitable for various industrial processing applications, but will produce some undesirable marginal effects. Such negative effects include uncontrolled and excessive inlet and outlet pressure loss, and local reverse flow. Zone or vortex, and trap zones, etc. These components that cause additional pressure drop include venturi, fluid nozzle, cavities (square edge of thin plate, quadrant edge, eccentric and arcuate), centrifugal, and linear impedance.

The following example demonstrates the specifications of a set of friction flow element:

The inner diameter of the spiral coil is 0.0625 inches, the length: 20 inches, and the number of turns: 2.5 turns. At room temperature, the water flow rate is between 0.5cc/sec and 5cc/sec.

The inner diameter of the spiral coil is 0.156 inches, the length: 40 inches, and the number of turns: 5.5 turns. At room temperature, the water flow rate is between 1cc/sec and 30cc/sec.

The inner diameter of the spiral coil is 0.250 inches, the length: 20 inches, and the number of turns: 2.5 turns. At room temperature, the water flow rate is between 2.5 l/min. and 5 l/min.

The inner diameter of the spiral coil is 0.375 inches, the length: 20 inches, and the number of turns: 2.5 turns. At room temperature, the water flow rate is between 2 l/min. and 10 l/min.

In some applications, the fluid pressure entering the fluid inlet 12 (Figures 1 and 8C) may be too low or too high. In order to adjust the fluid pressure, an auxiliary input module 200 as shown in Figure 3 can be used as an upstream supply module. The auxiliary input module 200 has a body or container 90 and four normally-closed (biased by the spring 97) poppet valves 91. The four poppet valves are fixed between the module base 92 and the cover 93 . As shown in the figure, four fluid parts 94 and 94A are inherently locked on the base 92. One of the parts is the pressure port, the other part is the vacuum port, the third part (94A) is the fluid inlet, and the fourth part is the exhaust port. Four press-in connection type parts 95 are fixed on the cover 93, and nitrogen is supplied to actuate the poppet valve 91. After that, the poppet valve 91 is opened to allow fluid to flow to the ports 94 and 94A. A fluid outlet 98 is provided at the bottom of the main body 90. The liquid level sensor 96 is installed on the main body 90 with the bracket 101 to sense the fluid level in the module main body or the container. The body 90 can also be provided with a filter (not shown).

In order to fill the module 200 with a pressurized fluid source, the inlet valve and the exhaust valve can be opened substantially at the same time, and the pressurized fluid can flow into the module. After a period of time, or the liquid level sensed by the liquid level sensor has reached When the preset value is reached, the inflow of pressurized fluid is stopped. The exhaust valve can be used to equalize the pressure so that the fluid passing through the inlet valve can flow into the container 90. After that, the inlet and exhaust valves are closed, and the fluid supply pressure valve is opened. If fluid needs to flow into the system, the fluid control valve 10 can be opened at the same time.

If the pressure of the fluid from the supply source is too low, pressure can be applied along with the filling cycle to increase the supply pressure. The application of such pressure can be continuous or only when necessary. Similarly, when the pressure of the fluid supply changes irregularly, the pressure must also be applied.

If a non-pressure supply source is used, the inlet and the vacuum valve can be opened substantially at the same time. The vacuum valve is used to draw fluid from the fluid source.

The module 200 can also be used as a defoamer. In particular, as mentioned above, the filling part in the cycle is used for the pressure fluid source. Once the container 90 has been filled to the desired liquid level, the inlet and exhaust valves are closed, and vacuum is applied to the fluid for a programmable time or desired time, so that bubbles can be removed from the fluid .

In another embodiment of the present invention, it is very advanced for saving space, and the valve used is shown in Figs. 12-23. Similar to the valve in Figure 8, the upper end cap 71' of the valve in Figure 12 includes two concentric circular rings 84', 85', and a circular groove is defined between the two to accommodate the top pneumatic ring 74' synthetic rubber O-ring 72', this O-ring can seal the valve pneumatic diaphragm 73' in the housing. A plurality of opposing threaded valve buckles 76' are used to sandwich the valve upper diaphragm 77' and the valve bottom diaphragm 78', and are biased by a spring 80'. The internal assembly is held together with a threaded fastener screwed on a stainless steel screw, bolt or tip 75'. The outer assembly is held in a non-contact manner with the valve bottom end cover 82', stainless steel tip or bolt 83', and the valve upper end cover 71'. A press-in connection type component is connected to the upper end cap 71' of the valve, and the pneumatic proportional control valve 20 is pneumatically connected by appropriate piping or the like. The flow path (between the inlet and the outlet) in the fluid control valve 10 is not in-line, so the pressure drop and the unswirled volume as illustrated in Figure 27D can be further reduced. The valve's off-position inlet and outlet can make thick liquids or other liquids flow easily and minimize the accumulation.

The valve housing 70' is preferably designed as a molded type, so that the sensor housing and the valve are made integrally. Unlike the sensor housing 60 in Fig. 8, this integrated embodiment only requires a single sensor end cap 65', which can greatly reduce the number of components required and prevent catastrophic failures. Mao Xian (burr).

In the valve housing embodiment shown in Figures 12-14, the flow system enters the inlet of the valve inlet 12' and flows into the linear channel 12A' until it reaches the circular cavity 90' through which the inlet cavity 99' is passed. Once the valve is opened, the fluid tends to spiral around the cavity 90'. After that, it passes through the two diaphragms and enters the narrow annular channel and enters the second cavity. This situation is the same as the previous implementation shown in Figures 8B and 8D. The case is the same. The spiral fluid flow path is through an outlet hole (not shown), and the linear path 13A' faces the outlet 13'. This path is generated in the second hole 89'. In order to improve the pressure loss between the cavities 90' and 89', so that the pressure drop generated in the device can maximize the swirling effect of the fluid, as mentioned above, a plurality of areas or removals can be provided on the valve sealing surface. Camfers (e.g. 0.04 inches). The fluid inlet path 12A' and the fluid outlet path 13A' are preferably arranged along the tangent direction of the cavities 89' and 90' (preferably along the axial diameter direction), in addition to contributing to the uniform flow of the fluid In addition, it can improve the pressure drop. The inlet 12' and the outlet 13' can be of external screw thread type, which is convenient for connecting appropriate hoses.

Located downstream of the flow path 13A' of the first and second cavities 90' and 89' is a first sensor housing 60'. The flow system of the sensor housing 60' is in communication with the second cavity 89' and the outlet 13'. The pressure and/or temperature sensor 64' is sealed in the housing 60' with an O-ring 63' such as perfluoroelastomer (KALREZ). The end cover 65' is connected to the housing 60' by a plurality of bolts or tip pieces 66', etc. The sensor 64' is used to sense the pressure and/or temperature on the fluid path between the inlet and the outlet of the sensor housing 60', and send an indication signal of the sensed value to a controller.

This embodiment of the valve may also include a second sensor housing 160', which preferably has the same structure as the sensor housing 60'. As shown in Figure 13, the flow system of the second sensor housing 160' is connected to the inlet 112' and the outlet 113' separated from the inlet 112'.

Therefore, the valve of this embodiment, referring to Figures 14A and 14B, has the following functions. The flow system flowing to the inlet of the valve port enters the inlet 12', and flows through the passage 12A' to the first valve cavity 90' and is contained therein until the valve is opened. Once the valve is opened, fluid flows from the first valve cavity 90' to the second valve cavity 89'. The fluid is sent out from the second valve cavity 89' through an outlet hole and enters the first sensor housing 61'. The pressure and/or temperature sensor of the fluid senses the fluid in the housing 61' and records it. And/or send a message to the controller. The flow system is sent out from the valve through the outlet 13', passing through the friction flow element, which is preferably in the shape of a coil, and then re-enters the valve assembly through the inlet 112', as shown in Figure 14B. The flow system flows into the second sensor housing 160', where the pressure and/or temperature can be sensed and recorded, and/or transmitted to the controller. After the fluid flows out of the second sensor housing 60', it travels through the valve assembly via a properly arranged path to maximize the use of space, and returns to the same side of the device where the fluid enters the earliest.

In order to design the valve assembly with pneumatic characteristics on one side and mechanical characteristics on the other side, multiple valve assemblies can be used to stack them into a single unit, which can further save space and save cost. Therefore, as shown in Figure 13, the size and configuration of the sensors 60' and 160' are the same, and the sensor 60' is equidistant from the outlet 113', and the sensor housing 160' is the same as the entrance 112' separated. Therefore, if the two are stacked vertically, the valve cavity becomes vertical alignment. Figure 15 is an example of this type of stacked valve assembly. In order to accommodate the pneumatic side components and mechanical side components of the valve, the middle cover (Middle cover) 171' is designed to have an inner part of both an upper end cover 71' and a lower end cover 82'. The stacked valve assembly is particularly suitable for fluid supply with limited space and multiple points of supply. As for other advantages, only a single proportional manifold, a single LED and main PC board, a single housing and cables are required, so two sets of components are not required. In various applications, it includes chemical mixing (proportional measurement control), synchronized supply of separate fluids, independent supply of two separate supply points, integrated independent or non-independent control, and continuous supply in continuity, etc.

The convenient design of the valve assembly can achieve substantial versatility. For example, the valve assembly shown in Figure 16 has a valve and a single sensor housing. The dimensions of the various components of the valve should preferably be consistent with the valve shown in Figure 13 to maintain stackability when needed, and if necessary, it can also be used as an additional sensor housing as shown in Figure 18. . Indeed, by providing the removable sensor housing insert as shown in Figure 18 as separate components, the device can construct one or more sensor housings, in which each sensor housing system is inverted Installation (for valve cavity) helps to remove bubbles.

Various components can be pre-molded into an in-line shape. For example, the valve shown in Figure 17 does not have a sensor housing. Figure 19 has a dual sensor housing insert. The inlet 112', 212' and outlet 13', 113' of the sensor housing are made of external thread type, which is convenient for fixing the valve. The embedded parts used in the sensor housing part of the valve assembly can be in many different combinations, and can be replaced by these embedded parts to form the sensor housing upside down, acting as a valve after installation , According to the positioning of the valve to help the removal of air bubbles, as mentioned above. Similarly, the interchangeable type of pneumatic and mechanical components can also invert the bamboo port and the outlet of the molded valve, which can be used for upstream or downstream pressure control. When pneumatic and mechanical components are installed on the opposite end of the valve cavity, the differential pressure of the system can be reversed, and the differential pressure upstream of the valve can replace the downstream pressure and be recorded. This will allow the use to monitor the pressure supplied to the system unit instead of the pressure downstream close to the discharge point. Figures 23A and 23B show the upstream and downstream models, respectively. The two figures illustrate the versatility of the molded valve design, in which each pneumatic component and each mechanical component, depending on whether the valve is expected to be upstream or downstream of the pressure drop, can be located on either side of the valve. The location of the sensor can also provide monitoring of the consumer's system status, not just for the monitor of this device.

Figures 24A and 24B are an example of a molded component form that can be used on a flow controller. The controller can be equipped with a Mykrolis LHVD type through the three ports (exhaust, inlet, and outlet) at the bottom of the device. The ability of filter pairing. This design can accept a LHVD type filter device.

The present invention can also use a traditional bubble sensor. The bubble sensor sends an adjusted signal to a controller and converts the signal into a percentage of air. If this percentage exceeds the preset level, the user is notified. Applicable bubble sensor can be light-sensitive or capacitive, and has two outputs (ON and OFF). When placed in the whole time, it can count the majority of ON and OFF, and transform it into a thick substance or fluid. The percentage of air in the air.

Figures 25A and 25B are an example of a valve design in no bubble trap location. The fluid enters through the inlet of the valve and goes up in a straight line, and the bubbles rise to the top. The remaining flow path is a continuous diameter path and the sensor bag-shaped pieces located below the path, so there are no bubbles for trapping and capture (the characteristic of traditional valves is that the gas cannot escape the plural The bag shape is it). Compared with the previous embodiments, this design can also reduce 3 components, including the fluid diaphragm, valve end caps and fasteners, etc., so it can reduce assembly costs, material costs, and complexity. In addition, two important fluid sealing spaces can be reduced, including one of the diaphragm tongue and groove seal, and the interference fit between the two fluid diaphragms.

When a pressing pressure is applied between the fluid diaphragm 401 and the pneumatic diaphragm 402, when the pneumatic pressure is greater than a spring pressure that is preloaded and biased to close the valve, the valve is driven to open. Since the pneumatic diaphragm 402 is larger than the fluid diaphragm 401, and the two diaphragms are mutually restrained by the screw 403 and the fastener 404, a larger load will be caused on the pneumatic valve 402 and the valve will be opened. The pressure is supplied through a barb fitting 405 (Figure 25B) and a pipe (such as polyethylene) 406. The pneumatic cavity 410 is sealed with an O-ring 407, the tongue and groove of the pneumatic diaphragm, as shown in the figure. The sensor 411 is sealed with an O-ring 412, and a sensor end cover 413 is fixedly attached.

In another embodiment, in order to reduce 90-degree turns, the design shown in Figure 26 can be modified. The sensor hole is moved to the side of the valve. The deviated flow path can eliminate the turning of the fluid and eliminate the unscrewable area. Because there is no O-ring on the pneumatic side, and due to factors such as the design and size of the diaphragms, the hysteresis of this valve is very small. In terms of poppet design, the highest quality linearity can also be achieved. The flow rate of the fluid will change substantially and directly proportionally with the pressure applied to the valve. In the whole work process<img file="TWI294792B_D0001.tif" />NS.

Figures 28A and 28B show another embodiment of the fluid control valve, in which an O-ring is used to separate the fluid diaphragm and the pneumatic diaphragm. This way can prevent excessive loading on the two diaphragms and reduce the life of the valve. The flow path of the fluid control valve is not used for high points of air to capture the collapse (unless there is a small amount of air available for collection at the sensor seals located on one side of the fluid control valve body). The flow path of this fluid control valve is designed to have a single fluid diaphragm. There is no high point in the valve (not including the pressure sensor sealing method). In the flow path of the fluid, there is no air for trapping. The trapped air trapped in the fluid control valve will be harmful to the discharge end once the fluid control valve is closed, and the air may also be decompressed. The trapping of air traps in the fluid control valve is also not conducive to the beginning of fluid discharge. The trapping of air in the fluid control valve will also cause other air to dissolve into the flow or form fine bubbles that are harmful to the wafer.

When air pressure is applied to the pneumatic cavity 410' between the pneumatic diaphragm 402' and the pneumatic closed O-ring 415, the valve is actuated. Turn on. The pressure applied to the surface of the pneumatic diaphragm 402' causes it to deform and force the fluid diaphragm 401'. Therefore, a diaphragm 401' is compressed by the diaphragm 402' by the screw 403' and the fastener 404', so the diaphragm 401' is Was opened. The pneumatic sealing O-ring 415' can prevent any air pressure from reaching the fluid diaphragm, so it can prevent the pneumatic pressure from exerting an excessive load on the two diaphragms. The pressure is supplied through the barbed part 405' and appropriate piping. An optional sensor cavity 500 can be arranged above the valve seal. This design can prevent air from falling into the fluid cavity, the inlet channel, the outlet channel, and the channels connected to the sensor cavity and the sensor cavity. Due to the flow in the tangential direction, the unscrewable area can be prevented. Therefore, the fluid inlet channel is set tangent to the inner diameter direction of the valve fluid cavity 90'. All high points are within the fluid path, or none are higher than the fluid path. There are no sharp corners in the flow path, so the fluid flow is very smooth.

Various designs and its flexibility make it possible to combine multiple valves and sensors to form a modular assembly, and provide various configurations to construct multiple valves, sensing devices, and flow Components such as meters, flow controllers, pressure controllers and temperature controllers. Therefore, Figure 20 shows a stacked flow controller and ON/OFF valve assembly, including a first valve 300, a second valve 300', and first and second sensors 310, 310', the flow system of which is consistent with A friction flow element 15 communicates. Figure 21 shows a stack of 4 sensors 310, 310', 320, and 320'. Figure 22 shows a flow controller and flow meter assembly.

Figures 24A and 24B show another embodiment of the molded valve design. Its configuration is used for a flow controller, and it can be combined with a LHVD (Low Hold-up Volume Device) through 3 ports at the bottom of the device. )-Type filter devices are paired. Of the three ports, port 610 is the exhaust from the filter, port 612 is the inlet to the filter, and port 614 is the outlet from the filter.

According to another embodiment of the present invention, it can be used as a valve auxiliary function. It can be used in traditional valve parts that use solenoid valves, needle valves, etc. to change the pressure changes applied to each valve part. Typically, the pressure is slowly dissipated. In the stop part of the sequence control, the flow rate change applied to the suction part of the valve is reduced, and the suction valve can assist the stop valve. As shown in Figure 29 of the present invention, during the OFF time of the control valve (or stop valve), the suction valve pressure can be reduced to assist the stop. Once the OFF time of the control valve is terminated, a suction delay can be provided, and the pressure is still constant on the suction valve. After this preset delay, the pressure applied to the suction valve decreases again until the pressure of the suction valve reaches a preset level, and the suction valve returns to its normal or rest position. This sequence control helps to keep liquid droplets from dripping from the nozzle opening. In another embodiment, the suck-back auxiliary action is delayed for a period of time after the control valve is activated; or the set action can be shortened, and the suck-back valve action is only activated when the control valve stops. At first it happened. The description here is that although the aforementioned pressure is an actuated method, if any valve actuation method is used, such as a motor, it still falls within the scope of the present invention.

The first case

The system has been set up so that a known differential pressure and a fixed supply (discharge) time can be input to the controller, and the sequential excitation by a shingle computer can be used as a supply liquid. The synthetic output stream of deionized water is captured in a container and weighed with a precise gauge to determine its substance. Using the known density of each supplied substance and fluid material, the capacity of each supply can be calculated. Combine the supply capacity and the known supply time to determine the flow rate. The test viscosity ranges from about 0.92 to about 9.5 centipaise (centipaise) for the fifth fluid with different viscosities. The relationship between pressure and flow rate is shown in Figure 10.

Case 2

Three types of valves are used for the hysteresis test, including two commercially available valves and one valve shown in Figures 8A to 8D of the present invention. The operating pressure of the valve fluctuates up and down, and the pressure in the test system fluctuates in stages through the operating pressure range of the valve. The measurement result is depicted as a voltage. Specifically, the establishment of this test is the valve closing system and the downstream pressure sensor, and the valve is under constant pressure, and the valve action is the process of closing the valve to fully open and then back to close, and the pressure sensor It is the person who monitors the pressure change downstream of the valve pressure.

The results of the test are shown in Figures 9A, 9B and 9C.

In each graph, the farthest point of the curve to the right represents the data used to change the pressure from low to high, and the left part of the curve is the change of pressure from high to low. The difference between the curves is the amount of hysteresis. Therefore, the pressure changes up and down according to the steps of the actuation pressure. If there is no hysteresis, the two curves will overlap. Figure 9C shows the valve according to the present invention. In terms of hysteresis, this commercially available valve is far less.

Case 3

This example is an application example of an embodiment of the present invention, which is used for the processing of chemical mechanical planarization substrates, which can be used to measure and control the flow rate of fluids so that the fluids can be used as feeds of respective flow rates (volumes). Specifically, this example illustrates how the embodiment of the present invention can be used to measure and control liquid flow, and can supply polishing liquids of different volumes on a substrate.

In the manufacture of optical lenses, chemical mechanical polishing is used. In the manufacture of semiconductor devices, chemical mechanical planarization is used. The polishing fluid can be acidic or acidic and can contain abrasives such as silica or alumina; the fluid used for polishing silica includes silica slurry, which is in the form of an aqueous potassium hydroxide solution; used for polishing copper Metal fluids include oxides such as peroxides, inhibitors such as Benzotriazole, and aqueous solutions of organic acids such as acetic acid.

The inlet of the embodiment of the present invention is connected to a container filled with polishing fluid and fed by pressure or gravity. The outlet of the flow device is connected to the nozzle of the polishing tool. The polishing tool has a substrate to be polished, which is rotated by a rotating pad or belt for polishing. The substrate is in contact with a polishing pad, and the polishing pad can remove material from the substrate according to the chemical reaction of the fluid. The polishing flow system is sent to the substrate on the appliance through the nozzle; the flow of the polishing fluid supplied to the nozzle is controlled by the flow device and its electronic function. The electronic function of the mobile device can be connected to the controller of the appliance, so that the appliance can control the discharge timing of the polishing fluid supplied to the substrate. The device can also include a polishing end point detector, which can also be used to control the timing of the polishing fluid sent to the substrate. The electronic signal processor in the flow device can eliminate the fluctuation of the polishing fluid supply flow caused by the pressure change in the pressure vessel containing the polishing fluid. Compared with a peristalic pump, the supply of the polishing liquid of the present invention is a constant flow rate. This method of controlling the volume of the polishing fluid and the supply rate to a substrate can reduce the waste of chemical substances, and can make the substrate be polished uniformly and repeatedly.

Case 4

This example of an embodiment of the present invention is to measure and control the amount of fluid, so each volume of fluid can be sent to a vaporizer to form gas. Specifically, this embodiment illustrates how the present invention can be used to measure and control the fluid sent to a vaporizer.

The liquid used is a chemical liquid, which can be heated in a vaporizer to become a gas. The vaporized gas is then sent to a heated substrate in a reaction chamber. On the heated substrate, the gas can be further decomposed or reacted. The gas can also be used to form a metal film, a semiconductor, or form a dielectric on the substrate (chemical gas deposition or particle layer chemical gas deposition). The gas can be used to etch the surface of the substrate or to dry the substrate. piece. The liquid used can be pure liquid, such as: water, 2-propane, or tetraethyl orthosilicate, TEOS, etc. The liquid used may also contain solids such as strontium dipivaloylmethane, Sr (DPM), etc. dissolved in a tetrahydrofuran (tetrahydrofuran) solution. Some liquids used, such as copper (I) hexafluoropentanedionate vinyltrimethylsilane, (VTMS) Cu (hfac), etc., are all thermally sensitive and can be analyzed by the thermal sensor used in the flow meter. The general flow rate of the liquid used is about 0.1 to 50 grams per minute. In the coating of optical devices such as lenses and optical fibers, thin films are very important. In the manufacture of various flat panels, microprocessors, and memory devices, the engraving of films and films is also very important.

According to an embodiment of the flow device of the present invention, its inlet is connected to a pressure supply source using liquid. The outlet of the flow device is connected to a vaporizer. The valve for the flow device can be located on the upstream or downstream side of the vaporizer. The outlet of the vaporizer is connected to the processing chamber of the appliance, which contains the substrate to be treated with gas. When multiple liquids need to be used for multiple processing, multiple flow devices can be used. The electronic function of the flow device can be connected to the controller of the appliance. This allows the treatment device to remotely control the flow of the liquid in the entire process from the pressured supply source, through the flow meter and then into the heated vaporizer. Vaporizers used for chemical gas deposition include: heated metal frits, heated valves, and heated piping.

The pressure change in the container containing the used liquid will change the flow rate of the liquid sent to the vaporizer. The thermal decomposition of the liquid used in the heat flow element will also make the flow of the liquid to the vaporizer inaccurate. Because the vaporizer will be saturated, the flow of liquid to the vaporizer is not well controlled, which will result in incomplete vaporization of the liquid. Incomplete vaporization will cause the droplets to drip into the processing chamber and then onto the intended substrate, causing defects in the substrate. According to the exercise result of the embodiment of the present invention, the fluid used for the control of the heat flow element and the fluid supplied to the vaporizer are not repetitive and controlled. In addition, there is no information about the fluctuation of the upstream pressure.

Case 5

This example of an embodiment of the present invention is used to measure and control the flow of liquid, so that the liquid can be applied to a substrate for electroless plating. Specifically, this example illustrates that an embodiment of the present invention can be used to control the discharge amount of a series of chemical substances applied to a substrate to form a metal film during the plating process. This kind of treatment can eliminate the removal of chemical substances required for general immersion bath plating treatment.

Various metals and metal alloy solutions used for plating include (but not limited to): silver, copper, platinum, palladium, gold and tin, etc. Usually, a catalyst is needed to activate the plating solution on the substrate. These catalysts include: colloidal palladium, carbon, graphite, tin-palladium, colloids, and conductive polymers such as polypyrrole, etc. Some of these catalysts and metals in the plating solution are used for plating treatment At that time, due to its high price and a lot of waste, it must be austere to reduce the cost of the plating process. In addition, some metals in these solutions are toxic when they are plated, so the amount of metal discharged into the environment must be minimized, and the cost of waste disposal must be reduced.

For each chemical substance used in the plating process, the inlet of the device according to an embodiment of the present invention is connected to a pressured, pumped, or gravity-fed chemical supply source. The outlet of this embodiment of the present invention is connected to the nozzle that intends to release the chemical substances onto the substrate. Using a heat exchanger, cooler, or resistive heater element, etc., the temperature of the solution can be lowered or raised before it is delivered to the substrate. For example, in electroless processing, copper metal can be deposited (grown) on the substrate. The process is: through a first flow device, the substrate and the colloidal palladium-containing activator are brought into contact; using a second flow The device uses water to rinse the substrate; a third flow device is used to contact the catalyzed substrate with a hydrochloric acid active solution; and a fourth flow device is used to exchange the substrate with a reducing agent containing acid copper ions and similar to formaldehyde ,Compounding agent similar to EDTA, salty similar to potassium charged, etc., come in contact with a certain volume of copper solution. The substrate is washed with water in the second flow device.

The electronics (function) of each flow device can be connected to the controller of the plating equipment to adjust the timing, cycle, and sequence of liquid supply through each flow device. If so, in each processing step, each chemical substance can be quickly and accurately delivered to the substrate with the measured volume. Since only adequate chemicals are supplied on the substrate to achieve a complete reaction, improper consumption of chemicals can be reduced, thereby reducing material costs. In addition, the pollution caused by the dragging of chemical substances on the substrate can also be reduced. Furthermore, due to the rapid response of the flow element and the reduction in the cycle time of the valve, the overall throughput of the treatment is also increased.

Case 6

This example of an embodiment of the present invention is used to measure and control the flow of liquid so that the fluid supplied on a substrate can form a uniform coating. Specifically, this example illustrates how the embodiment of the present invention measures and controls the flow rate of the fluid applied to the substrate, so that the liquid material can be precisely coated on the substrate.

In the spin coating processing method, the liquid or slurry deposited on the substrate is generally used, including dielectric materials, photoresists, anti-reflection coating materials, polyimide, such as hexamethyldisilazane as a viscosity promoter , Ferroelectric materials, and sol...gel solids (sol-gel), etc. These materials are supplied on a static or slowly rotating substrate with a fixed or mobile nozzle. After the coating material is applied to the substrate, the substrate is rotated at a high speed of about 100~5000rpm, and the coating material on it will be uniformly spread and coated to form a thin film of liquid material on it. In this treatment, it is important that many of these materials are very cheap, and the amount of use is small, and the waste is small. For repetitive coating, the amount of fluid applied to the substrate must be consistent.

The inlet of this embodiment of the flow device is connected to the container which contains the coating liquid and is fed by pressure or gravity, and the outlet is connected to the nozzle on the coating device. The covering device has a substrate fixed with a rotating chuck. The coating liquid system is sent to the substrate on the appliance through the nozzle; the coating liquid system flowing to the nozzle is controlled by the flow device and its valves. The electronic function of the flow device can be connected to the controller of the appliance so that the appliance can control the timing and flow rate of the coating liquid applied to the substrate. With the connection of the electronic function and the flow device, the coating device can change the flow of the fluid according to factors such as the nozzle position and the rotation speed of the substrate to achieve the desired coating. The signal processor of the flow device can eliminate the change in the volume and flow of the coating liquid caused by the pressure change of the container containing the coating liquid. As a result, the coating liquid system is delivered to the substrate with a controlled volume. As a result, in addition to reducing the waste of chemical substances, the plurality of substrates can be uniformly and repeatedly coated.

Case 7

This example of an embodiment of the present invention is used to measure and control the flow rate of the fluid to make it react on a substrate. Specifically, this example illustrates that this embodiment of the present invention can be used to measure and control the flow rate of a reactive fluid applied to a substrate, if possible. The reactive liquids include, but are not limited to, such as positive or negative photoresist imaging agents, photoresists, strippers, acids such as hydrofluoric acid, such as ozone-type deionized water Oxidizing agent, or etchant such as peroxy acid, etc.

In the flow device of this embodiment of the present invention, the inlet is connected to the pressure or gravity-fed container containing the reaction liquid, and the outlet of the flow device is connected to the nozzle on the appliance. The reaction liquid system is sent to the substrate on the appliance through the nozzle; the flow device and its valve are used to control the reaction fluid flowing into the nozzle on the appliance. The electronic function of the flow device can be connected to the controller of the appliance, so that the appliance can control the application timing and flow rate of the reaction fluid applied to the substrate. The electronic function of the flow device can also be connected to a reaction end point detector via the controller of the appliance. When the reaction end point is approached or reached, the flow of the reaction fluid can be reduced or stopped. A representative example of the etching process is the use of peroxyacids to remove copper from the edge of the plated wafer. By applying this embodiment of the present invention, the flow rate of the reaction liquid applied to the substrate can be controlled, and the end point of the treatment can be precisely controlled.

Example 8

This example uses an embodiment of the present invention to connect a plurality of chemical substance sensors in series to measure and control the flow rate and composition (composition, or composition) of the fluid. Specifically, this example illustrates how the implementation of the present invention is connected in series with one or more chemical substance sensors to control the flow rate and fluid composition of the fluid. The application of this kind of control hope includes (but not limited) plating tanks, RCA cleaning tanks, ozone-type water tanks, and hydrofluoric acid acid tanks. An embodiment of the present invention incorporates other applications of the sensors, including maintaining the purification of a chemical substance tank. For example, the increase of pollutants in a circulating tank, such as particles, organic materials, or metal ions, may require periodic discharge of the polluting fluid in the tank and replacement with the same amount of non-polluting fluid . In addition, this tank can also be switched to a purifier or particle filter. When a constant flow rate is maintained, pollutants can be removed at the same time. Until the pollutants can be removed, the current treatment and products can be protected.

For the removal of organic materials on the surface of various substrates, deionized water with ozone dissolved in it can be used. Irregular changes in the output gas concentration in the ozone generator will cause changes in the concentration of ozone dissolved in the water. This change in the dissolved ozone concentration will result in the time required to oxidize the surface of the substrate using ozonized water, and will also cause the adverse consequences of inconsistent processing and cleaning time.

In order to maintain the concentration of dissolved ozone in an overflow cleaning tank, according to an embodiment of the present invention, the inlet is connected to the source of deionized water, and the outlet is connected to a gas contactor. The gas contactor is a substance conversion device that can dissolve various gases into liquids. This kind of device and its operation description can be seen in the products provided by WL Gore, Elkton, MD, and Mykrolis Corporation, Bedford, MA. etc. The ozone gas system generated by the ozone generator is sent to the shell side of the gas contactor, where the ozone gas is dissolved into the deionized water flowing through the gas contactor tube. The concentration of ozone dissolved in the water can be measured by an ozone dissolved concentration monitor manufactured and sold by Needham, MA, USA, and connected to the fluid outlet of the gas contactor. The signal output by the ozone dissolved concentration monitor is used as an input signal for the electronic function of the flow device of the present invention. The electronic function of the present invention can change the flow of water flowing through the gas contactor within a preset limit, so that ozone can be dissolved in the water according to the preset concentration. For example, if the ozone concentration output by the ozone generator decreases, the flow device can reduce the flow of water flowing through the gas contactor, so as to maintain a certain concentration of ozone dissolved.

In addition, the electronic function of the flow device of the present invention can be used to change the gas flow rate or power level of the ozone generator with an appropriate device, and at the same time, it can also keep the flow rate through the gas contactor constant, regardless of the flow device. The upstream water pressure. For example, if the dissolved ozone concentration exceeds a preset threshold and the flow of water is constant, the power applied to the ozone generator can be reduced to reduce the dissolved ozone concentration and restore its proper concentration.

According to the embodiment of the present invention, it is possible to control the preparation and delivery of a chemical mixture so that it is applied to a substrate with a constant composition.

Case 9

The application of this example of an embodiment of the present invention is to measure and control the flow rate of an organic liquid to make it flow at a low flow rate.

The pressure drop element used is a PFA tube with a length of 40 inches, an inner diameter of 0.058 inches, and a twist number of 14. The inlet fluid is 2 propane, the temperature is 23°C, and it comes from a container source, and the gauge pressure is 20 psi. 2 The flow rate of propane is determined by the controller set point (SO), and the action sequence of the valve is controlled by an external computer. According to an embodiment of the present invention, the amount of 2 propane sent is measured on an Ohaus Analytical Plus Balance, and the recorded amount is a function of time on a second computer using the RS232 port of Balance. Regarding the 2-propane substance is the relationship with time, draw the curve as shown in Figure 11. Figure 11 also shows the segment curve of each optimal supply. The best curve slope for each segment is the flow rate of 2 propane in grams per second. It can be seen from the result that the flow rate of fluid in the flow system can be supplied within the range of 0.0083 grams per second (0.16 grams per minute) to 0.49 grams per second (9.6 grams per minute). This kind of flow system controls the flow rate. It is suitable for various chemical gas deposition processes.

<p>10. . . Fluid control valve</p><p>12. . . Fluid inlet line</p><p>13. . . Fluid outlet line</p><p>15. . . Friction flow element</p><p>15A, 15B. . . Straight part</p><p>12'. . . Entrance</p><p>12A'. . . path</p><p>13'. . . exit</p><p>13A'. . . Linear path</p><p>20. . . Pneumatic proportional control valve</p><p>twenty one. . . Retract valve</p><p>twenty four. . . No. 1 pressure sensor</p><p>25. . . 2nd pressure sensor</p><p>30. . . Control circuit</p><p>60. . . Sensor housing</p><p>61. . . Fluid inlet</p><p>62. . . Fluid outlet</p><p>63. . . O-ring</p><p>64. . . Pressure and temperature sensor</p><p>65. . . End cap</p><p>66. . . Tip pieces</p><p>60'. . . The first sensor housing</p><p>63'. . . O-ring</p><p>64'. . . Pressure/temperature sensor</p><p>65'. . . Single sensor end cap</p><p>66'. . . Tip pieces</p><p>71. . . Valve upper end cover</p><p>72. . . O-ring</p><p>73. . . Valve pneumatic diaphragm</p><p>74. . . Pneumatic ring</p><p>75. . . Stainless steel bolt</p><p>76. . . Threaded buckle</p><p>77. . . Valve upper diaphragm</p><p>78. . . Valve bottom diaphragm</p><p>70'. . . Valve housing</p><p>71'. . . Valve upper end cover</p><p>72'. . . O-ring</p><p>73'. . . Valve pneumatic diaphragm</p><p>75'. . . Bolts/tips</p><p>76'. . . Threaded buckle</p><p>77'. . . Valve upper diaphragm</p><p>78'. . . Valve bottom diaphragm</p><p>80. . . spring</p><p>82. . . Valve bottom end cap</p><p>83. . . Stainless steel tip</p><p>84. . . Concentric circular ring</p><p>85. . . Concentric circular ring</p><p>86. . . Push-in type linear parts</p><p>88. . . Pneumatic hole</p><p>89. . . hole</p><p>82'. . . Valve bottom end cap</p><p>83'. . . bolt</p><p>84'. . . Concentric circular ring</p><p>90. . . Round hole</p><p>91. . . Poppet valve</p><p>92. . . Narrow circular channel</p><p>93. . . Shoulder</p><p>94. . . Fluid parts</p><p>95. . . Push-in parts</p><p>96. . . Level sensor</p><p>97. . . spring</p><p>98. . . Fluid outlet</p><p>99. . . Entrance cavities</p><p>90'. . . hole</p><p>99'. . . Entrance cavities</p><p>100. . . case</p><p>105. . . LED (light emitting diode) board</p><p>106. . . Main printed circuit board</p><p>110. . . Valve manifold</p><p>112'. . . Entrance</p><p>113'. . . exit</p><p>160'. . . 2nd sensor housing</p><p>200. . . Auxiliary input module</p><p>310. . . Perceptron 1</p><p>320. . . Sensing device</p><p>310'. . . Perceptron 2</p><p>320'. . . Sensing device</p><p>401. . . Fluid diaphragm</p><p>402. . . Pneumatic diaphragm</p><p>403. . . Screw (bolt)</p><p>404. . . buckle</p><p>405. . . Barbed parts</p><p>406. . . Piping</p><p>407. . . O-ring</p><p>401'. . . Fluid diaphragm</p><p>402'. . . Pneumatic diaphragm</p><p>403'. . . Screw (bolt)</p><p>404'. . . buckle</p><p>405'. . . Barbed parts</p><p>411. . . sensor</p><p>412. . . O-ring</p><p>413. . . End cap</p><p>410'. . . Pneumatic hole</p><p>415'. . . O-ring</p><p>500. . . Wire</p><p>502. . . Wire</p><p>504. . . Wire</p><p>610. . . mouth</p><p>612. . . mouth</p><p>614. . . mouth</p><p>800. . . compressed spring</p><p>902~930. . . step</p><p>924. . . step</p><p>926. . . step</p><p>2700. . . Controller</p><p>2702. . . Power supply</p><p>2704. . . Management processor</p><p>2705. . . Pressure circuit</p><p>2706. . . Auxiliary function circuit</p><p>2708. . . Control valve driver</p><p>2709. . . Suction valve actuator</p><p>2710. . . interface</p><p>2712. . . Control processor</p><p>2714. . . Flash memory</p><p>2716. . . Computer readable instructions</p><p>2802. . . Expansion port</p><p>2810. . . Dual-port RAM (random access memory) section</p><p>2902. . . Upstream pressure input</p><p>2904. . . Downstream pressure input</p><p>2905. . . Analog/digital converter</p><p>2906. . . Analog/digital converter</p><p>2908. . . Analog/digital converter</p><p>2910. . . Correction circuit</p><p>2911. . . Input/output circuit</p>

Figure 1 is a block diagram of an embodiment of the present invention.

Figure 2 is an oblique view of a housing for accommodating a pneumatic part and a fluid control part of a motorless pump or liquid supply module according to an embodiment of the present invention.

Figure 3 is an exploded view of an auxiliary input module according to an embodiment of the invention.

Figure 4 is a schematic diagram of a differential amplifier according to an embodiment of the present invention.

Figure 5 is a graph of valve gain according to an embodiment of the present invention.

Figure 6 is a flowchart of a control system according to an embodiment of the present invention.

Figure 7 is an exploded view of a pressure transducer according to an embodiment of the present invention.

Figure 8A is a partial exploded view of the proportional valve end according to an embodiment of the present invention.

Fig. 8B is a cross-sectional view along the BB direction of Fig. 8A.

Fig. 8C is a cross-sectional view of Fig. 8A in the direction of CC.

Fig. 8D is a cross-sectional view along the DD direction of Fig. 8A.

Fig. 8E is an exploded view of the proportional valve shown in Fig. 8A according to an embodiment of the present invention.

Figure 9A shows the hysteresis curve of a traditional Furon valve.

Figure 9B shows the hysteresis curve of the traditional SMC valve.

Figure 9C shows the valve shown in Figure 3 with its hysteresis curve.

Figure 10 is a graph showing the flow rate versus pressure drop in 5 different fluids.

Figure 11 is a graph showing the matter and time of 2-propane flow rate according to the ninth example.

Figure 12 is an exploded view of a valve according to another embodiment of the present invention.

Figure 13 is an oblique view of the one-piece valve and sensor in Figure 12.

Fig. 14A is a cross-sectional perspective view of the valve of Fig. 12 on the fluid inlet side.

Figure 14B is a cross-sectional perspective view of the valve of Figure 12 on the fluid outlet side.

Figure 15 is an oblique view of a stacked valve according to an embodiment of the present invention.

Figure 16 is an oblique view of a valve with a single sensor housing according to an embodiment of the present invention.

Figure 17 is an oblique view of a valve without a sensor housing according to an embodiment of the present invention.

Figure 18 is an oblique view of a single sensor housing according to an embodiment of the present invention.

Figure 19 is an oblique view of a dual sensor housing according to an embodiment of the present invention.

Figure 20 is an oblique view of a flow controller and ON/OFF valve assembly according to an embodiment of the present invention.

Figure 21 is an oblique view of a sensing device according to an embodiment of the present invention.

Figure 22 is an oblique view of a flow controller and flow meter assembly according to an embodiment of the present invention.

Figure 23A is an oblique view of a valve according to an embodiment of the present invention when the downstream pressure is differential.

Figure 23B is an oblique view of a valve according to an embodiment of the present invention when the upstream pressure is differential.

Figures 24A and 24B are perspective views of a valve according to another embodiment of the present invention.

Figures 25A and 25B are cross-sectional views of a valve according to still another embodiment of the present invention.

Figure 26 is a sectional view of a valve according to another embodiment of the present invention.

Figures 27A-C are cross-sectional views of some commercially available valves similar to the fluid control valve of the present invention, and Figure 27D is a cross-sectional view of an embodiment of the present invention.

Figures 28A and 28B are cross-sectional views of a valve according to another embodiment of the present invention when it is in a closed and partially opened position.

Figure 29 is a timing/control curve diagram when the auxiliary function is stopped according to an embodiment of the present invention.

Figure 30 is a block diagram of a controller that can generate a valve drive signal according to an embodiment of the present invention.

Figure 31 is a block diagram of an embodiment of the control logic circuit of the controller.

Figure 32 is a block diagram of an embodiment of a pressure control circuit.