Patent Publication Number: US-10315814-B2

Title: Transfer cap

Description:
BACKGROUND 
     Field of Art 
     The present disclosure relates to a transfer cap for a photoresist container. 
     Description of the Related Art 
     It is often necessary to ship chemically hazardous fluids such as photoresist. These fluids are typically shipped via a bottle that includes a cap. 
     Japanese Laid-Open Patent Application 2000-142772 discloses a cap that includes a filter and a pressure release valve which releases pressure from the container if the container becomes over-pressurized. While, Japanese Laid-Open Patent Application 2008-230691 discloses a bottle cap with a tube connected to the bottle cap. Also, US Patent Publication No. 2009/0049988 discloses a container with a gas-permeable vent that has a liquid-tight gas-permeable seal. U.S. Pat. No. 4,643,825 discloses a shipping container that includes a bung with at least two openings. One of the openings of the bung includes a dip tube. Another opening of the bung includes a gas filter. Both openings of the bung are sealed with plugs during shipment of the filled container. 
     Shipping containers with one or more ports such as a vent port and/or a dispensing port experience multiple issues. For example, a shipping container may experience leaks when opening the vent port on a resist bottle. These leaks may take the form of resist bubbling out the vent port. This can cause problems for shipping hazardous materials. In addition, during transport and shipping overseas, the liquid can flow into one or more of the ports if and when the bottle gets pressurized. If the vent port is uncapped under these conditions, there is no protection against residual fluid flowing or shooting out of the newly opened port. This situation poses a safety hazard especially when handling chemically hazardous fluids. 
     US Patent Publication No. 2015/0083274 discloses a universal manifold for attaching to various different storage containers. US Patent Publication No. 2001/0013882 discloses bottles that use a puncture seal to deliver the liquid to a main reservoir. US Patent Publication No. 2006/0012659 discloses a bottle that is shipped with a solid cap. Once the bottle is received the solid cap is unscrewed and a cap with a dip tube is attached. These systems can cause problems with purity by generating particles and also allowing contaminates to enter the bottle. 
     What is needed is a system that is both safe and allows for the purity of the material to be maintained at a high level. 
     SUMMARY 
     At least a first embodiment, may be a cap that is capable of being fitted to a bottle. The cap may comprise a transfer port and a vent port. The vent port may include a membrane and a valve. 
     At least a first embodiment, may be a cap wherein the bottle is configured for storing and transporting liquid. 
     In an aspect of the first embodiment, the transfer port is a liquid transfer port for draining or filling fluid in and out of the bottle. 
     In an aspect of the first embodiment, a valve is one of a poppet valve, a check valve, and a manual vent. 
     In an aspect of the first embodiment, the cap may further comprise a drain port with a connector in the cap allowing the attachment of a drain tube onto the cap extending away from the bottle. 
     In an aspect of the first embodiment, the membrane may be made of expanded PTFE. 
     In an aspect of the first embodiment, the transfer port may comprise a dip connector and a transfer connector. The dip connector may allow the attachment of a dip tube onto the cap extending into the bottle. The transfer connector may allow the attachment of a transfer tube onto the cap extending out of the bottle. In an aspect of the first embodiment, the dip connector and the transfer connector may be compression fittings or screw fittings. 
     In an aspect of the first embodiment, a cap may further comprise an additional port. The additional port may comprise an additional dip connector allowing the attachment of an additional dip tube onto the cap extending into the bottle. In an aspect of the first embodiment, the additional port may further comprise an additional transfer connector allowing the attachment of an additional transfer tube onto the cap extending out of the bottle. In an aspect of the first embodiment, the additional transfer tube may connect the cap to at least one of a reservoir and a valve. 
     In an aspect of the first embodiment, when the valve is open the vent port may allow gas to pass through the vent port and does not substantially allow liquid to pass through the vent port. In addition, when the valve is closed the vent port may not substantially allow gas or liquid to pass through the vent port. 
     In an aspect of the first embodiment, the valve may open automatically when internal pressure on the bottle side of the cap is outside an internal pressure range. In an aspect of the first embodiment, a manual vent port may be opened if the valve that opens automatically fails. 
     In an aspect of the first embodiment, bulk material of the membrane may be made of a material that is compatible with cleaning techniques which are capable of removing ions and small molecules from throughout the membrane to a level of at least 1 ppb. 
     In an aspect of the first embodiment, the ion leaching of materials used for manufacturing of the cap may provide ion cleanliness levels &lt;1 ppb for elements: Na, Ca, Fe, K, Zn, Al, Mg, Ni, Cr, Cu, Pb, Mn, Li, Sn, Ba, Co, Sr, and Pd. 
     In an aspect of the first embodiment, materials of the membrane, the valve, a surface of the transfer port, and a surface of the vent port may be made of material that is compatible with cleaning techniques which are capable of removing ions and small molecules from their surfaces to a level of at least 1 ppb. 
     In an aspect of the first embodiment, one or more of the materials used for fabricating the cap may be selected from: polypropylene; polyethylene; and fluorinated plastics, such as polyvinylidene fluoride; and PTFE. 
     An aspect of a second embodiment, is a method of using a cap attached to a bottle. The cap may comprise: a transfer port and a vent port that includes a membrane and a valve. The method may comprise: removing one of a cap or a plug from the vent port; opening the vent port with a manual valve; removing one of a cap or a plug from the fluid port; attaching the bottle to a reservoir via a transfer tube; and activating a pump to draw liquid out of the bottle via the transfer tube and into the reservoir. 
     An aspect of a third embodiment, is a liquid transfer system. The liquid transfer system may comprise: a bottle containing a liquid; a cap attached to the bottle; a reservoir; a transfer tube connecting the reservoir to the transfer port; and a pump to draw liquid out of the bottle via the transfer tube and into the reservoir. The cap may comprise: a transfer port and a vent port that includes a membrane and a valve. 
     These and other objects, features, and advantages of the present disclosure will become apparent upon reading the following detailed description of exemplary embodiments of the present disclosure, when taken in conjunction with the appended drawings, and provided claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Further objects, features and advantages of the present disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying figures showing illustrative embodiments of the present disclosure. 
         FIGS. 1A-B  are illustrations of cross sections of transfer caps. 
         FIG. 2  includes illustrations of cross sections of valves. 
         FIG. 3  is an illustration of a cross section of a transfer cap as used in an embodiment. 
         FIG. 4  is an illustration of a cross section of a transfer cap as used in an embodiment. 
         FIGS. 5A-D  are illustrations of top down views of different embodiments of the transfer caps. 
         FIG. 6  shows a cross section of a transfer cap as used in combination with a bottle as used in an embodiment. 
         FIG. 7  shows an additional cross section of embodiment as used in combination with a bottle. 
         FIG. 8  is an illustration of a method of using the transfer cap. 
         FIG. 9  is an illustration of a system in which an embodiment might be used. 
     
    
    
     Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the subject disclosure will now be described in detail with reference to the figures, it is done so in connection with the illustrative exemplary embodiments. It is intended that changes and modifications can be made to the described exemplary embodiments without departing from the true scope and spirit of the subject disclosure as defined by the appended claims. 
     DETAILED DESCRIPTION 
     What is needed is a solution that will prevent safety hazards associated with previous caps while maintaining cleanliness requirements and also adding functional features such as a having a built in transfer port in the cap. The environment in which the transfer port is used has a very high cleanliness requirement. The transfer cap is part of a larger system which should not add more than 5 ppb worth of contamination over a year of continuous use. In order to keep defects low it is important that all components and materials used can be cleaned to a high level of cleanliness, which can then be maintained over the life of the product. 
     First Embodiment 
       FIGS. 1A-B  are illustrations of cross sections of transfer caps. Transfer cap  100  is an example of a first embodiment. The transfer cap  100  includes a transfer port  102  and a vent port  104 . The transfer cap  100  illustrated in  FIG. 1A  includes a top portion that may have a larger diameter than the bottom portion. The transfer port  102  may be a transfer port for draining, filling, and/or sampling fluid in and out of the bottle. 
     The bottom portion of the transfer cap  100  illustrated in  FIG. 1A  may include threads which interface with internal threads of a bottle (not shown). The bottom portion of the transfer cap  100  illustrated in  FIG. 1B  may include threads which interface with external threads of a bottle. In an alternative embodiment, the transfer cap  100  may not include threads but instead includes a snap fitting which interfaces with a lip on the bottle. The bottle may be configured for storing, transporting, and dispensing a fluid such as a photoresist and like liquids. 
     The transfer cap  100  may include a seat which also interfaces with the bottle. The seat of the transfer cap  100  may be capable of forming a liquid tight seal with the bottle. A gasket may also be used in conjunction with the transfer cap to form the liquid tight seal. In an alternative embodiment, the seat of the transfer cap may be capable of forming a gas tight seal and a liquid tight seal with the bottle. 
     The vent port  104  of the transfer cap  100  includes a membrane  106  and a valve  108 . Because the membrane  106  may pose a cleanliness concern, it may need to be subject to harsh chemicals so that it can meet high cleanliness specifications. The membrane  106  may be made of expanded PTFE. The valve  108  may include a vent opening  110 . The valve  108  may be threaded or unthreaded. The valve  108  may be opened by unscrewing or by being raised. The valve  108  may include instead of threads a snap fitting that interfaces with a lip in the vent port  104 . The valve  108  may form a substantially gas tight and liquid tight seal when closed. The valve  108  may control the rate at which gas and/or liquid is released when the valve  108  is in an open position. The release rate may be controlled by the size of the vent opening  110 . 
     The membrane  106  is configured to allow gas to pass while not allowing liquid to pass. The pore size of the membrane  106  may be configured to allow some low molecular weight gases (Nitrogen, Oxygen, etc,) to pass. 
     The membrane  106  may be placed in the vent port  104  as illustrated in  FIGS. 1A-B  below the valve  108 . In an alternative embodiment, a membrane  206  may be incorporated into a valve  208  as illustrated in  FIG. 2 . The valve  208  may include a hollow portion  209  that allows gas to pass towards the membrane  206  as illustrated in  FIG. 2 . 
     The transfer port  102  may be configured to accept a dip tube  312  as illustrated in  FIG. 3 . In one embodiment, the dip tube  312  may be press fitted into the cap  100 . In an alternative embodiment, the dip tube may include threads which screw into internal threads which are in the transfer port  102 . In another embodiment, the dip tube  312  may include a snap fitting that interfaces with a lip inside the transfer port  102 . In a further embodiment, the transfer port  102  extends outward from the cap  100  and into the bottle. The portion of the transfer port  102  that extends into the bottle may include external lips, threads, or other fittings which interface with the dip tube  312 . The dip tube  312  may extend the length of the bottle. In an alternative embodiment, the dip tube  312  may be threaded through the entire length of the transfer port as a single continuous tube extending to the bottom of the bottle and having a segment above the transfer cap  100  with connectors that attach to an external system such as a reservoir or a pump. 
     The transfer port  102  may be configured to accept a compression fitting  414  (or screw fitting). The compression fitting  414  may form a gas tight seal and liquid tight seal with the cap  100 . The compression fitting  414  is configured to accept a transfer tube  416  and form a gas tight seal and a liquid tight seal with the transfer tube  416 . Alternatively, the transfer tube  416  may be inserted directly into the transfer port  102 . In another alternative, the transfer tube  416  and the dip tube  312  may be combined into a single tube. 
       FIG. 5A  is a top down view of the cap  100  in which the vent  108  is shown adjacent to the transfer port  416 .  FIG. 5B  is a top down view of a cap  500   b  which is substantially similar to cap  100  except that it includes an additional vent  508 . The vent  108  may be a controlled vent port while the vent  508  may be a manual vent override. The vent  108  may include a pressure release valve which opens when the pressure differential is above a threshold such as 0.2 psi or 1 psi or when the internal pressure is outside an internal pressure range. The vent  108  may allow a gas to be released if the container becomes over-pressurized due to outgassing, temperature increases, etc. The vent  108  may also be configured to let gas in to prevent a partial vacuum from exceeding a threshold as the fluid is pumped out of the bottle.  FIG. 5C  is a top down view of a cap  500   c  which is substantially similar to cap  100  except that it includes an additional vent  508  and an additional transfer port  416   c .  FIG. 5D  is a top down view of a cap  500   d  which is substantially similar to cap  100  except that it includes an additional vent  508 , an additional transfer port  416   c , and an additional transfer port  416   d . The additional transfer ports  416   c  and  416   d  are substantially similar to the transfer port  416 . Each of the additional transfer ports  416   c - d  may have separate functions such as: a sample port for testing the liquid in the bottle; a filling port for refilling the bottle; a separate transfer port for transferring fluid to a separate location or at a higher rate. One or more of the additional transfer ports  416   c - d  may be a drain port with a connector allowing an attachment of a drain tube onto the cap extending away from the bottle. In an embodiment, a plurality of dip tubes that extend into the bottle may be connected to a plurality of ports in the cap. In an embodiment, a plurality of transfer tubes that extend from the bottle may be connected to a plurality of ports in the cap. 
       FIG. 6  is an illustration of a transfer cap  600  used in combination with a bottle  626  containing a liquid  624 . A dip tube  612  may be inserted into the transfer cap  600  forming a gas tight and a liquid tight seal with a compression fitting, screw fitting, etc. The transfer cap may include a secondary vent port in which a plug  618   a  is inserted providing a gas tight and a liquid tight seal. When removed the plug  618   a  provides a membrane free secondary vent port to allow additional venting. The transfer cap  600  may include one or both of a dip connector for connecting the dip tube and a transfer connector for connecting a transfer tube. 
     During shipment, the primary vent port  604  of the transfer cap  600  may be capped with a plug  618   b  as illustrated in  FIG. 6 . These plugs  618   a - b  or caps may be removed to expose the vent valve and flow pathway. These caps keep the flow paths and ports clean during storage and shipping. The dip tube or dip port may also include a cap or plug. The plug  618   b  may form a gas tight seal and/or a liquid tight seal with the transfer cap  600 . A membrane  106  may be included in the primary vent port  604 . The primary vent port  604  may include a manual shut off valve  622  which forms a gas tight seal and/or a liquid tight seal with the primary vent port  604  when the valve is closed. When the manual shut off valve  622  is open and plug  618   b  is removed gas may pass through the membrane  106  while liquid does not pass through the membrane  106 . The primary vent port  604  may include a pressure release valve  620  when the pressure differential is above a threshold such as 0.2 psi or 1 psi. The pressure release valve  620  may be in addition to or a replacement for the manual shut off valve  622 . In an embodiment, the manual shut off valve may be in series or in parallel to the pressure release valve  620  and may be opened if the pressure release valve  620  fails. 
     The membrane  106  may be a porous material that allows vapor to pass and prevents liquid from escaping. The membrane  106  may made of a frit or membrane material such as: glass; metal; expanded PTFE; PEEK; Polyethylene; Polypropylene, etc. The membrane material is a chemically resistant material which does not react with the material that is intended to be stored in the bottle. The membrane material may also be chemically resistant to cleaning solvents and other materials that are to be used in combination with the bottle. The membrane  106  may have pore size between 50 nm to 500 μm. In an embodiment, the membrane pore size may be between 30 μm to 70 μm. The membrane pore size impacts the desired flow rate for venting and the time required to trigger the vent valve. 
     The pressure release valve  620  may be triggered to open when there is a partial vacuum and/or over pressurization above a threshold inside the bottle and may be triggered to close at the end of the fluid transfer. The close of the pressure release valve  620  can prevent the dripping of liquid out of the transfer tube when the transfer tube is disconnected from a pump. The pressure release valve  620  may be triggered open when a pressure differential inside the bottle is greater than 0.2 psi or greater than 1 psi for controlled venting. 
     The transfer cap may include a manual gas release valve in addition to a plug  208  that is built into the transfer cap which the user can open or close to vent gas in a controlled manner. The manual gas release valve may be a captive luer plug or a needle valve. 
     This transfer cap allows the bottle  626  to vent to the atmosphere while liquid  624  is being pumped out. For example, when a critical vacuum is reached within the bottle  626 , the valve  620 , which may be a poppet valve or duckbill valve, is triggered to open. 
     Materials used for the transfer cap and the associated components may meet &lt;1 ppb ion cleanliness and are chemically resistant to material stored under the cap and in the bottle. Chemically resistant in this context is material that does not substantially get swollen, get brittle, oxidize, etc, when exposed to the material stored in the bottle and the environment in which the bottle is used. The ion leaching of materials used for manufacturing of the cap may provide ion cleanliness levels &lt;1 ppb or alternatively &lt;10 ppb for elements: Na, Ca, Fe, K, Zn, Al, Mg, Ni, Cr, Cu, Pb, Mn, Li, Sn, Ba, Co, Sr, and Pd. The materials of the membrane, the valve, a surface of the transfer port, and a surface of the vent port are made of material that is compatible with cleaning techniques which are capable of removing ions and small molecules from the membrane, the valve, a surface of the transfer port, and a surface of the vent port to a level of at least 1 ppb. The bulk material of the membrane may be made of material that is compatible with cleaning techniques which are capable of removing ions and small molecules from throughout the membrane to a level of at least 1 ppb. The materials used for fabricating the cap may be selected from: polypropylene; polyethylene; fluorinated plastics such as polyvinylidene fluoride; and PTFE. 
     In an embodiment, a transfer tube is connected to a pump pulling on liquid in the tubes and bottle. Initially, the valve  620  is closed and does not open until a target cracking pressure (like 1 psi or lower) is reached. The transfer tube is connected to the pump and continues to pump down the bottle until a low vacuum is achieved which triggers the opening of the valve  620 . Then liquid flows out of the bottle and into a reservoir. In an embodiment, a transfer tube may connect the cap to one of a reservoir, a valve, or a pump. 
     Second Embodiment 
     An alternative embodiment is a transfer cap insert  700  which is used in combination with a bottle cap  728  as illustrated in  FIG. 7 . The bottle cap may include a hole or may be modified to include a hole. The transfer cap insert  700  is fitted to make a gas tight and liquid tight seal with the hole in the bottle cap  728 . The bottle cap  728  may be a standard bottle cap which works with the bottle  626  which is modified to include a hole in which the transfer cap insert  700  is inserted into. 
     Methods 
     A preparation method of using the transfer cap may include preparing a bottle and transfer cap for shipment as illustrated in  FIG. 7 . The preparation method may include a step of inserting a valve and a membrane into a vent port of the transfer cap. The preparation method may include steps of cleaning the bottle and transfer cap and inserting a clean transfer tube into the transfer cap. The preparation method may include a step of opening a mechanical valve on the vent port if the vent port has a mechanical valve. The preparation method may include a step of attaching the clean transfer cap to the bottle. The preparation method may include a step of filling the bottle through the transfer tube. After the bottle is filled the preparation method may include a step of capping or plugging the transfer tube or transfer port. The vent valve may then be closed and the vent port may be capped or plugged. The bottle is now ready for transport. 
     The transfer cap may be used in a transfer method  830  of inserting the bottle with the transfer cap into a system in which the bottle is used as illustrated in  FIG. 8 . The transfer cap may include a membrane and a valve. The transfer method may include a step  832  of removing a cap or plug from the vent port. After the vent port is opened, the membrane may be exposed to the ambient environment. If the vent port includes a mechanical valve the mechanical valve may be opened in a step  834 , after which a cap or plug may be removed from a transfer tube or a transfer port in a step  836 . The transfer tube may then be connected to a reservoir in a step  838  or other part of the transfer system. A pump may be between the reservoir and the transfer tube. A pump may then be activated to draw liquid out of the bottle via the transfer tube and into the reservoir. An automatic valve of the vent port may open automatically when vacuum pressure inside the bottle is greater than a threshold. 
     System 
     An embodiment may be used in combination with a liquid transfer system as illustrated in  FIG. 9 . The liquid transfer system includes a bottle containing a liquid substantially similar to the bottle illustrated in  FIGS. 6-7 . A transfer cap may be attached to the bottle. The transfer cap includes at least a transfer port and a vent port. The vent port includes at least a membrane and a valve. 
     The liquid transfer system may also include a reservoir  942 , a transfer tube, and a pump  940 . The pump  940  may draw liquid out of the bottle via the transfer tube and into the reservoir  942 . The transfer tube may connect the pump or the reservoir to the transfer port. The pump may be in the reservoir, may be connected to reservoir, or may between the reservoir and the transfer port. 
     The valve of the vent port may open automatically when vacuum pressure inside the bottle is greater than a threshold. 
     In describing example embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner. 
     While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.