Patent Document

CROSS-REFERENCE TO RELATED APPLICATION(S) 
   None. 
   BACKGROUND OF THE INVENTION 
   This invention relates to a storage and dispensing system for the storage and dispensing of liquids. In particular, the invention relates to using a radio frequency identification tag and a radio frequency antenna to assure proper association of a particular liquid to a particular process. 
   Certain manufacturing processes require the use of liquid chemicals such as acids, solvents, bases, photoresists, dopants, inorganic, organic and biological solutions, pharmaceuticals, and radioactive chemicals. Often, these processes require a specific liquid chemical for each particular process. Furthermore, each process may require a specific liquid chemical at various stages of the process. Storage and dispensing systems allow alternative containers to be used to deliver liquid chemicals to a manufacturing process at a specified time. Consequently, manufacturing personnel need to change the liquid chemical being used for the particular process at the specified time so that the system delivers the correct liquid chemical to the manufacturing process. It is critical that the proper liquid chemical be installed into the systems for the particular process. If the incorrect liquid chemical is installed for a particular process, personnel may be put at risk. Furthermore, equipment and the articles under manufacture may be severely damaged. 
   Prior art systems have attempted to utilize unique pump connectors that will only fit with a correct container. Each container has a unique configuration based on the liquid chemical contained therein. The intention is that only the correct chemical can be used in any particular manufacturing process, because the process will dictate a unique pump connection and a corresponding container with the correct chemical liquid. One example of such a system is disclosed in Osgar et al., “Liquid Chemical Dispensing System With Sensor,” U.S. Pat. No. 5,875,921. The Osgar system uses physical configurations, called key codes, to prevent accidental dispensing of an improper liquid from a container. Both the container and a connector have unique key code configurations. The connector must have the same key code configuration as the container for the connector to be properly coupled with the container. The Osgar system also employs a sensor that senses proper coupling of the connector to the container. When the sensor senses a proper coupling of the connector to the container, a pump is enabled. When the container and the connector are not properly coupled, the pump is disabled. 
   Some prior art systems, however, do allow the pump connectors to be partially connected to the incorrect chemicals such that pumping can take place even though the connection is not proper. In addition, personnel have a propensity to attach the wrong chemical to the wrong process or at the wrong time. Such incorrect connections can be dangerous to personnel and have caused millions of dollars of damage to equipment and to articles of manufacture. A system that could provide a reliable connection between the correct chemical and the correct process, and that could track incorrect connection attempts by personnel would be a useful improvement over the prior systems. 
   SUMMARY OF THE INVENTION 
   The present invention is a system for handling liquid and a method for the same. The system has a container capable of holding a liquid. A storage means is coupled with the container for electronically storing information relating to the liquid stored in the container. The system also has a communication means, for storing information to and reading information from the storage means. Finally, the system has a controller means, coupled with the communication means, for controlling processing of the liquid based on information read from the storage means by the communication means. 
   In a preferred embodiment, a cap is also coupled with the opening such that the liquid is sealed in the container. A radio frequency identification (RFID) tag is mounted on the cap which is capable of electronically storing information. The RFID tag comprises a passive RF transponder and an electrically erasable programmable read-only memory (EEPROM). A connector is coupled with the cap such that the liquid can be dispensed from the container through the connector. A radio frequency (RF) antenna is mounted on the connector which stores information to and reads information from the EEPROM on the RFID tag. A microprocessor-based controller is coupled with the RF antenna such that the controller controls processing the liquid from the container based on information read from the RFID tag by the RF antenna. 
   In another preferred embodiment, the connector further comprises a connector head and a probe extending from the connector head. The probe is insertable through a center of the cap and into the opening. The probe has a flow passage. A pump is coupled with the probe and with the flow passage for pumping liquid through the probe and the flow passage. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a system for storing, dispensing and processing liquids in accordance with the present invention. 
       FIG. 2  shows a filling system for filling a container with liquid. 
       FIG. 3  shows a preferred embodiment of a processing system for dispensing and processing liquid. 
       FIG. 4  shows a user-interface in the processing system for dispensing and processing liquid shown in FIG.  3 . 
   

   DETAILED DESCRIPTION 
     FIG. 1  shows system  10  for storing, dispensing and processing liquids in accordance with the present invention. System  10  includes filling system  12  and processing system  14 . 
   Filling system  12  includes a plurality of liquids  16  and containers  18 . In operation of filling system  12 , liquids  16  are dispensed into containers  18 . Liquids  16  are typically liquid chemicals including acids; solvents; bases; photoresists; dopants; inorganic, organic, and biological solutions; pharmaceuticals; and radioactive chemicals. Filling system  12  tracks which of liquids  16  is placed into which containers  18  so that liquids  16  in containers  18  can be identified later, as will be discussed more fully below. After filling of containers  18  has been completed, containers  18  are transported to processing system  14 . 
   Processing system  14  includes a plurality of containers  18  and processes  20 . In operation of processing system  14 , liquids  16  contained in containers  18  are used in processes  20 . For example, containers  18  may contain a liquid chemical such as photoresist for use in the manufacturing of integrated circuits. Processing system  14  reads containers  18  to determine which liquids  16  are contained within them so that the proper liquid  16  is used in the proper process  20 , as will be discussed more fully below. 
     FIG. 2  shows filling system  12  for filling a container with liquid. Filling system  12  includes microprocessor-based control unit  32 , electrically erasable programmable read-only memory (EEPROM) writer  34 , liquid reservoir  36 , cap  38 , and container  18   a . Control unit  32  is electrically connected to EEPROM writer  34  and liquid reservoir  36 . Liquid reservoir  36  is connected to container  18   a . Cap  38  includes radio frequency identification (RFID) tag  42 . RFID tag  42  includes an EEPROM and a passive radio frequency transponder. EEPROM writer  34  is capable of writing to RFID tag  42  on cap  38 . 
   In operation of filling system  12 , control unit  32  regulates dispensing of liquid from liquid reservoir  36  into container  18   a . Typically, filling system  12  includes a plurality of liquid reservoirs  36  connected to control unit  32 . That is, control unit  32  typically regulates dispensing of a plurality of liquids into a plurality of containers  18 . For ease of illustration, a single liquid reservoir  36  and a single container  18   a  are shown. To begin operation of filling system  12 , control unit  32  sends a signal to liquid reservoir  36  instructing liquid reservoir  36  to begin dispensing liquid into container  18   a . Liquid reservoir  36  continues dispensing liquid into container  18   a  until container  18   a  is filled to an appropriate level. After container  18   a  is filled, liquid reservoir  36  sends a signal to control unit  32  indicating container  18   a  is full. Control unit  32  then sends a signal to liquid reservoir  36  to stop dispensing liquid into container  18   a.    
   After container  18   a  is filled, control unit  32  sends a signal to EEPROM writer  34 . This signal contains information about liquid contained in liquid reservoir  36 . EEPROM writer  34  subsequently programs the EEPROM contained in RFID tag  42  with information received from control unit  32  in a process known to the art. Information programmed to the RFID tag  42  includes, for example, the type of liquid dispensed into container  18   a  from liquid reservoir  36 , the producer of the liquid contained in liquid reservoir  36 , the date of filling of container  18   a  with liquid from liquid reservoir  36 , the date of expiration of the liquid contained in container  18   a , and similar useful information. Once container  18   a  has been filled and RFID tag  42  has been programmed by EEPROM writer  34 , cap  38  is secured onto container opening  44  of container  18   a . In a preferred embodiment, cap  38  is threadably connected to container opening  44  of container  18 . Cap  38  may also be secured onto container opening  44  by, for example, snapping cap  38  onto container opening  44  or vacuum sealing cap  38  onto container opening  44 . The method of securing cap  38  onto container opening  44  depends on the properties of the liquid contained in container  18   a . After cap  38  has been secured onto container  18   a , container  18   a  is transported to a processing system. 
     FIG. 3  shows a preferred embodiment of processing system  14 . Processing system  14  includes cap  38 , container  18   a , connector  50 , control unit  52 , and pump  54 . Container  18   a  includes container opening  44 . Cap  38  includes RFID tag  42 , rupturable membrane  56 , and membrane scores  58 . Connector  50  includes radio frequency (RF) antenna  60 , port adaptor  62 , modular antenna line  64 , adaptor tube  66 , and probe  68 . Probe  68  includes lower probe port  70  located adjacent probe tip  72 . In a preferred embodiment, cap  38  is threadably connected to container opening  44  of container  18   a . After container  18   a  with cap  38  are transported to the desired location, probe hole  74  and vent hole  76  are exposed. Rupturable membrane  56  is exposed through probe hole  74 . Rupturable membrane  56  has membrane scores  58  in its surface. Connector  50  is configured to be interconnected with cap  38 . 
     FIG. 3  shows how the components of processing system  14  are assembled. More specifically, connector  50  is shown being interconnected with cap  38  and container  18   a . Probe tip  72  is inserted through probe hole  74  and pressed against rupturable membrane  56  proximate to membrane scores  58 . When sufficient pressure is applied on connector  50  toward rupturable membrane  56 , probe tip  72  ruptures rupturable membrane  56  along membrane scores  58  allowing probe  68  to be inserted through membrane  56 . Continued pressure on connector  50  then allows connector  50  to be moved immediately adjacent cap  38 . Probe  68  is then in communication with the interior of container  18   a . As such, connector  50  is mounted on container  18   a . Adapter tube  66  and port adapter  62  provide a liquid passage from the interior of container  18   a  to pump  54 . When processing system  14  is properly assembled, pump  54  is capable of pumping the liquid in container  18   a  through port adapter  62  and adapter tube  66  to a manufacturing process, such as the manufacturing of integrated circuits. Typically, processing system  14  includes a plurality of containers  18 , a plurality of connectors  50 , and a plurality of pumps  54  connected to control unit  52 . That is, control unit  52  typically regulates dispensing of liquid from a plurality of containers  18  to a plurality of processes via a plurality of pumps  54 . For ease of illustration, a single connector  50 , a single container  18   a , and a single pump  54  are shown. 
   The operation of pump  54  is controlled by control unit  52 . Control unit  52  may receive input from an operator relating to starting and stopping pump  54 . For example, an operator seeking to start pumping the liquid chemical in container  18   a  to a manufacturing process may input this information to control unit  52 . 
   Control unit  52 , however, is also configured to receive signals from RF antenna  60  via either modular antenna line  64  or RF transmissions. In operation of processing system  14 , control unit  52  receives input from a process indicating a liquid needed by the process. For example, in the manufacture of integrated circuits, a layer of photoresist may be needed. Control unit  52  sends a signal to RF antenna  60 . Probe  68  of connector  50  is then inserted through probe hole  74  until connector  50  is immediately adjacent to cap  38 . Connector  50  is positioned such that RF antenna  60  is located adjacent RFID tag  42 . A signal requesting the information stored in the EEPROM of RFID tag  42  is then transmitted from RF antenna  60  to RFID tag  42 . The signal is received by the passive RF transponder contained in RFID tag  42 . The signal received by the transponder activates RFID tag  42 . Subsequently, information stored on the EEPROM contained in RFID tag  42  is read from the EEPROM to the transponder. The transponder then transmits the information contained on the EEPROM to RF antenna  60 . RF antenna  60  sends the information received from RFID tag  42  to control unit  52  via modular antenna line  64  or via a RF transmission. Control unit  52  compares information received from RF antenna  60  to information about the liquid needed by the process, and controls pump  54  accordingly. That is, if container  18   a  contains an undesired or unexpected liquid, control unit  52  will disable pump  54 . Conversely, if container  18  contains an expected and desired liquid, control unit  52  will enable pump  54 . 
   Consequently, when processing system  14  is not properly assembled and an operator, believing that processing system  14  is properly assembled, inputs information to start pump  54 , pump  54  will not operate. In this way, processing system  14  prevents the accidental operation of an improperly assembled system. This will prevent delivery of an improper liquid to a process. 
     FIG. 4  shows a preferred embodiment of user-interface  80  in processing system  14  for dispensing and processing liquid shown in FIG.  3 . User interface  80  includes touch screen  82 , microprocessor-based control unit  52 , bus control unit  84 , communication bus  86 , read/write devices  88 , connector  50 , cap  38 , and container  18   a . Touch screen  82  is connected to control unit  52 . Control unit  52  is connected to bus control unit  84 , typically via an Ethernet or other serial communications cable. Control unit  52  also receives input from a process. Bus control unit  84  is connected to read/write device  88  via communication bus  86 . Read/write device  88  is connected to connector  50  via modular antenna line  90 . Read/write device  88  may also communicate with connector  50  through remote antenna  92 . Connector  50  communicates with RFID tag  42  on cap  38  via RF antenna  60  using radio frequency transmissions. 
   For simplicity of illustration,  FIG. 4  shows a single connector  50  connected to communication bus  86  through read/write device  88 . In a typical system, a plurality of read/write devices  88  are connected to communication bus  86 , each read/write device  88  connected to different connectors  50  coupled with containers  18  containing different liquids. Containers  18  are typically situated in a plurality of drawers, each drawer containing a plurality of positions. Each position is configured to hold one container  18 . In operation of user-interface  80 , each of containers  18  is graphically displayed on touch screen  82  in its corresponding drawer and position within the drawer. For example, in a system having two drawers and four positions within each drawer, container  18   a  positioned in the second position of the first drawer is graphically displayed on touch screen  82  in the second position of the first drawer. When connector  50  is matched properly with container  18   a  (as described above), the graphic representation of container  18   a  on touch screen  82  is displayed in a first color, typically green. This indicates to an operator that the liquid contained in container  18   a  is ready for dispensing to a process. Conversely, if connector  50  is matched improperly with container  18   a  (as described above), the graphic representation of container  18   a  on touch screen  82  is displayed in a second color, typically red, and a warning message appears on touch screen  82 . This indicates to the operator that the liquid contained in container  18   a  will not dispense to a process until the mismatch is corrected. 
   When container  18   a  needs to be replaced (for example, when container  18  is empty), the operator removes container  18   a  from its position. Touch screen  82  then graphically displays container  18   a , along with the drawer number and position number of container  18   a . The operator then exchanges container  18   a  for new container  18   b , and couples connector  50  with new container  18   b . If connector  50  is matched properly with new container  18   b  (as described above), all containers  18  are displayed on touch screen  82  in the first color. If connector  50  is matched improperly with new container  18   b  (as described above), new container  18   b  is displayed on touch screen  82  in the second color and a warning message appears on touch screen  82 . 
   Touch screen  82  also allows the operator to choose from a variety of operations using RFID tag  42 . Each operation is selectable from a button on touch screen  82  which corresponds to each operation. For example, an operator may view information stored on RFID tag  42  about liquid contained in containers  18 , record information to RFID tag  42  about liquid in containers  18  (such as when the liquid is installed into its proper drawer and position, the shelf life of the liquid, what process the liquid is used in, when the liquid is used in a process, how much of the liquid is used in a process, etc.), or enable probe  68  for dispensing liquid from containers  18 . The operator touches the button on touch screen  82  corresponding to a desired operation. Touch screen  82  sends the selection made by the operator to control unit  52 . Control unit  52  subsequently commands bus control unit  84  to perform the selected operation. The selected operation is performed, and the result is displayed on touch screen  82 . 
   As an example, the operator may desire to view information stored on RFID tag  42  about liquid in container  18   a . The operator first pushes the button on touch screen  82  corresponding to this operation. Touch screen  82  sends this selection to control unit  52 . Control unit  52  then commands bus control unit  84  to access RFID tag  42  on container  18   a . To access RFID tag  42 , bus control unit  84  sends a signal along communication bus  86  to the read/write device accessing RFID tag  42 : read/write device  88 . Read/write device  88  then accesses RF antenna  60 , either via modular antenna line  90  or a RF transmission via antenna  92 . In this preferred embodiment, separation  100  between antenna  92  and RF antenna  60  is typically less than five meters for successful RF communication. Next, RF antenna  60  transmits a signal to RFID tag  42 . In this preferred embodiment, separation  102  between RF antenna  60  and RFID tag  42  is typically less than ten millimeters for successful RF communication. The signal is received by the passive RF transponder contained in RFID tag  42 . The signal activates RFID tag  42  and the requested information is accessed from the EEPROM contained on RFID tag  42 . The requested information is then read from the EEPROM by the transponder, and the transponder transmits the information back to RF antenna  60 . RF antenna  60  then sends the information to read/write device  88  either via modular antenna line  90  or via RF transmissions to antenna  92 . The information is sent along communication bus  86  to bus control unit  84 , which in turn sends the information to control unit  52 . Once received by control unit  52 , information about the liquid in container  18   a  is displayed on touch screen  82 . 
   The liquid dispensing system of the present invention prevents the accidental operation of an improperly assembled system by storing liquid in a container having a cap with a radio frequency identification tag containing electrically erasable programmable read-only memory. (EEPROM). The EEPROM stores information about the liquid contained in the container. In a processing system, the information contained on the EEPROM can be accessed to prevent the accidental dispensing of an improper liquid and to maintain a database of the liquids used in a process. Also, additional information about the liquid can be written to the EEPROM in the processing system, such as when the liquid is used in a process and how much of the liquid is used in a process. Furthermore, the present invention allows for a standardization of the cap, container, and connector, since the control system now responds to information read from the cap rather than upon sensing a physical connection. This allows for a reduction in the amount of hardware that was necessary to accommodate the physical connectability safety feature of prior art systems. 
   Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, other forms of electronic storage maybe used on RFID tag  42 , such as erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), and random-access memory (RAM). Also, the components of processing system  14  which communicate using radio frequencies may be configured to communicate using other areas of the electromagnetic spectrum, such as those in the areas of cellular or infrared communications.

Technology Category: y