Substrate container valve assemblies

A substrate container includes a container portion having an open side or bottom, and a door to sealingly close the open side or bottom, one of the door and the container portion defining access structure. The substrate container additionally includes a check-valve assembly, the check-valve assembly being retained with respect to the access structure to provide fluid communication with an interior of the substrate container. The check-valve assembly includes a grommet, the grommet being formed of an elastomeric material. A valve seat is disposed within the grommet, the valve seat being integrally formed with the grommet according to one aspect, and being formed of a separate piece according to another aspect. An elastomeric valve member, specifically an elastomeric umbrella valve member according to one aspect, is disposed within the grommet and held to engage the valve seat, thereby restricting fluid flow through the check-valve assembly with respect to the interior of the substrate container.

BACKGROUND

In general, substrate containers or carriers are used for transporting and/or storing batches of silicon wafers or magnetic disks before, during and after processing of the wafers or disks. The wafers can be processed into integrated circuits and the disks can be processed into a magnetic storage disks for computers. The terms wafer, disk, and substrate are used interchangeably herein and any of these terms can refer to semiconductor wafers, magnetic disks, flat panel substrates, reticles, and other such substrates, unless otherwise indicated.

The processing of wafer disks into integrated circuit chips often involves multiple steps where the disks are processed at various processing stations, and stored and transported between processing steps. Due to the delicate nature of the disks and their susceptibility to contamination by particles or chemicals, it is vital that they are properly protected throughout this procedure. Wafer containers have been used to provide this necessary protection. Additionally, since the processing of disks is generally automated, it is necessary for disks to be precisely positioned relative to the processing equipment for the robotic removal and insertion of the wafers. Another purpose of a wafer container is to securely hold the wafer disks during transport. The terms wafer containers, carriers, cassettes, transport/storage bins, and the like, are used interchangeably herein unless otherwise indicated.

During processing of semiconductor wafers or magnetic disks, the presence of or generation of particulates presents very significant contamination problems. Contamination is accepted as the single largest cause of yield loss in the semi-conductor industry. As the size of integrated circuitry has continued to be reduced, the size of particles which can contaminate an integrated circuit has also become smaller, making minimization of contaminants all the more critical. Contaminants in the form of particles may be generated by abrasion such as the rubbing or scraping of the carrier with the wafers, with the carrier covers or enclosures, with storage racks, with other carriers or with processing equipment. Additionally, particulates such as dust can be introduced into the enclosures through the openings or joints in the covers and/or enclosures. Thus, a critical function of wafer carriers is to protect the wafers therein from such contaminants.

Containers are generally configured to axially arrange the wafers or disks in slots, and to support the wafers or disks by or near their peripheral edges. The wafers or disks are conventionally removable from the containers in a radial direction upwardly or laterally. The containers may have a shell portion with a lower opening, a door to latch into the lower opening, and a discrete carrier that rests on the door. This configuration, known as a SMIF pod, is illustrated in U.S. Pat. Nos. 4,995,430 and 4,815,912, both owned by the owner of the instant application and both incorporated herein by reference. Additionally, wafer carrier assemblies can have front openings with doors that latch onto front openings, which are known as FOUPs or FOSBs, and are described in, for example, U.S. Pat. Nos. 6,354,601, 5,788,082 and 6,010,008, all of which are incorporated by reference herein. In certain configurations, the bottom covers or doors, front doors or the container portions have been provided with openings or passageways to facilitate the introduction and/or exhaustion of gases such as nitrogen or other purified gasses, into the wafer carrier assemblies to displace ambient air that might have contaminants.

Wafer containers and reticle containers known in the art have used various connection or coupling mechanisms for fluidly interfacing the flow passageways of the wafer containers to fluid supply and pressure or vacuum sources. Such attachment and sealing requires specialized components which may be of complex configuration. Certain current designs include a check valve having a frame, a plunger, O-rings and metal spring, one or more of which can lead to wafer contamination through the generation of particulates or other contaminants. Additionally, some purge-valve designs are susceptible to compressive forces during installation, potentially deforming a frame of the check valve and leading to leakage.

SUMMARY

According to one aspect of the disclosure, a substrate container includes a container portion having an open side or bottom, and a door to sealingly close the open side or bottom, one of the door and the container portion defining access structure. The substrate container additionally includes a check-valve assembly, the check-valve assembly being retained with respect to the access structure to provide fluid communication with an interior of the substrate container. The check-valve assembly includes a grommet, the grommet being formed of an elastomeric material. A valve seat is disposed within the grommet, the valve seat being integrally formed with the grommet according to one aspect, and being formed of a separate piece according to another aspect. An elastomeric disk shaped valve member retained by a central stem to the valve seat, for example an elastomeric umbrella valve member, according to one aspect, is disposed within the grommet and held to engage the valve seat, thereby restricting fluid flow through the check-valve assembly with respect to the interior of the substrate container.

The number of parts within a check-valve assembly is substantially reduced, in some cases including only two parts: an elastomeric grommet having internal structure defining one or more valve seats, and an associated elastomeric umbrella check valve member. The elastomeric valve member optionally is reversible within the grommet to restrict fluid flow through the check-valve assembly in an opposite direction. According to another aspect, a check-valve assembly includes only three parts: an elastomeric grommet, a substantially rigid housing within the grommet, and an elastomeric umbrella valve member.

A feature and advantage of embodiments of the invention is that an elastomeric disk shaped valve member cooperates with a flat elastomeric valve seat in a valve. The utilization of elastomeric valve component assembling and functioning with another elastomeric valve component provides ease of assembly and a high level of sealing integrity. With respect to an umbrella valve with a disk portion and a stem portion, the elastomeric stem portion in inserted into an opening defined by elastomeric material and the disk seats against the elastomeric valve seat. In embodiment the disk shaped member has a convex shape facing away from the valve seat in an unactuated state and the disk inverts, when actuated by gas passing through the valve, such that the shape is concave or flat facing away from the valve seat. In other embodiments, the disk may be flat in the unactuated state and change to a concave shape facing away from the valve seat when actuated with gas passing through the valve. In other embodiments the disk may be flat and be pivotally attached to the valve seat at a periphery of the disk and operate as a flap.

According to another aspect, a check-valve assembly is disposed in a stacked configuration, end-to-end with respect to a grommet. Various housings and retention mechanisms for check-valve assemblies also are disclosed. Other check-valve assemblies, check-valve modules, and associated methods are also disclosed.

DETAILED DESCRIPTION

FIG.1illustrates an example wafer container assembly2in which embodiments of the disclosure can be implemented. Container assembly2includes wafer carrier4, bottom door6, and enclosure portion8. Bottom door6is adapted to sealably couple with enclosure portion8to define an interior space that can be isolated from ambient atmosphere10. As shown inFIG.1, wafer carrier2can comprise a plurality of elements12, such as shelves, that can hold and position a plurality of silicon wafers or other substrates within wafer carrier2. Generally, elements12hold and position the substrates such that contact between adjacent wafers is minimized, which can reduce damage to the substrates that can occur during processing and/or transportation.

FIG.2illustrates an example bottom door6in more detail. Section6comprises access structures in the form of openings14,16. According to one embodiment, opening14facilitates the introduction of gases or other fluid transfer into container assembly2. Similarly, opening16facilitates the removal of gases or other fluid transfer out of container assembly2, e.g. such that gas or fluid located within container assembly2can be vented to the ambient atmosphere. Thus, according to one embodiment, opening14is an inlet, while opening16is an outlet. AlthoughFIG.2illustrates an embodiment where bottom door6comprises two openings14,16, embodiments having four, five, six, or more access structures located in bottom door6are contemplated and are within the scope of the present disclosure. It should also be understood that embodiments of the disclosure can be implemented in a section of container assembly2, or similar container, that is a non-removable, non-openable section.

As illustrated inFIG.2, openings14,16accommodate, or are disposed in association with, valve assemblies or modules according to the embodiments of the disclosure, illustrated generally at20,22. Valve assembly20is positioned at or within opening14to seal opening14, and valve assembly22is positioned at or within opening16to seal opening16. Valve assemblies20,22each create a seal against the interior of their corresponding opening14,16, and each provide at least one bore or passageway for passage of gas or other fluids. One of ordinary skill in the art will recognize that the size, cross-sectional shape, and other features of openings14,16and valve assemblies20,22can be guided by gas flow requirements, operating pressures, and other characteristics of a particular wafer container assembly or environment. Specific embodiments of valve assemblies20,22and associated components will be described with respect toFIGS.6-25.

FIGS.3-4illustrate another configuration of a wafer container assembly23, known as a FOUP (front opening unified pod) or FOSB (front opening shipping box), in which embodiments of the disclosure can be implemented. Container assembly23generally includes door24and container portion26. Container portion26has front opening30leading into container interior32where a plurality of wafers W are retained on wafer shelves35. Door24has key access holes36and latch mechanism38partially illustrated in the interior of the door enclosure. Latch tips41engage recesses39in the container portion door frame40.

Container assembly23has purge capabilities with a pair of forward purge ports48and rearward purge ports54. Ports48,54have purge grommets50secured into access structure or grommet receiving structure51, located on bottom52of container assembly23and optionally associated with each port48,54. Check valves56according to embodiments of the disclosure are inserted into the grommets to form valve assemblies that control the direction of purging gas fluid flow. Additionally, tubular environmental control components configured as purge towers60are illustrated, which optionally receive grommets62and check valves64. Specific embodiments of valve assemblies, grommets, check valves, and associated components will be described with respect toFIGS.6-25.

FIG.5illustrates one type of access structure or receiving structure51disposed in a wall or cover of a substrate container, for example bottom52or side cover of container assembly23, according to an embodiment of the disclosure. Structure51constitutes inlet or outlet structure for fluid passage into or out of container assembly23, and is constructed to receive and/or accommodate valve assemblies and modules along central axis66. Access structures or retaining structures contemplated in this disclosure function as purging ports and optionally include retaining structures having geometry specially adapted to sealably engage grommets or valve assemblies and modules. The grommets and assemblies/modules themselves optionally include various sealing features for creating fluid-tight contact with certain interior features of associated access or retaining structures.

FIGS.6-25illustrate various valve assemblies and modules, according to aspects of the disclosure, that can be implemented in or with respect to doors, side walls, bottom walls, purge tubes, or other components of wafer carriers such as those illustrated inFIGS.1-5, or other types of carriers and containers.

FIGS.6-25additionally illustrate various types of grommets or other structures used in sealing openings or ports in substrate containers, according to embodiments of the disclosure. Generally speaking, the grommets or structures include a body having a bore located within the body, the bore extending along the major axis of the body. Additionally, embodiments of grommets of the present disclosure comprise an operation element located with the bore. The operation element can comprise a check valve that can regulate the flow of gas or other fluids through the bore, a filter, a sensor or combinations thereof. The check valves employed in the present disclosure can be oriented within the bore such that the grommets can be used to seal both inlet and outlet openings on substrate container doors and/or enclosures. Additionally, the design of the grommet body optionally can facilitate sealing of the opening without the need for additional O-rings attached to the grommet. Furthermore, embodiments of grommets of the present disclosure can combine a grommet body, check valve and/or filter into an integral cartridge or module, which can improve the overall sealing ability of the grommets and can facilitate easier construction of substrate container assemblies. In some embodiments, the grommets have an axial height from about ⅛ inch to about 1 inch, while in other embodiments the grommets can have an axial height from about ⅜ inch to about ¾ inch. Additionally, embodiments of grommets of the present disclosure can have a diameter from about ¼ inch to about 1.5 inches, while in other embodiments the grommets can have a diameter from about ½ inch to about ¾ inch. One of ordinary skill in the art will recognize that additional ranges of axial height and diameter of the grommets are contemplated and are within the scope of the present disclosure.

The check valve members as illustrated have a disk and a valve seat connection portion configured as a central stem centrally attached to the disk. In other embodiments, the valve seat connection portion may be at a periphery of the disk such that the disk operates as a flap pivoting about the connection portion.

The grommets can be distinguished from O-rings known in the art in a number of ways. For example the grommet configuration provides an elastomeric element that is generally of a cylindrical configuration with a bore extending therethrough, the bore itself having a cylindrical configuration. The bore is of sufficient length to contain totally or substantially the entire length of an operational component inserted therein. The grommet preferably has at least one planar surface arranged to be normal to the axis of the grommet. Such surface can be utilized to effectively provide a seating surface for a nipple or nozzle as part of a purging system. Volumetrically, the grommet is preferably larger that the operational component, or any associated structure, contained within the grommet. The grommet preferably has a cross sectional area taken in an axial plane whereby the cross sectional area of the grommet is greater that the cross sectional area of the opening extending axially therethrough. The grommet preferably has an axial length that is greater than the diameter of the opening or bore extending axially through the grommet. Grommets described herein optionally have a non-circular cross-section in elevation, cylindrical inner facing surfaces, cylindrical outer facing surfaces, and planar end surfaces.

Turning to specific aspects of the disclosure,FIGS.6-8illustrate a first type of check-valve assembly100. Check-valve assembly100includes grommet105having internal structure108defining valve seat110. Internal structure108and valve seat110are disposed at substantially a midpoint of grommet105along its axial length, though other positions along the axial length are also contemplated. Grommet105optionally is a purge grommet, defining a purge grommet interface adapted to sealingly connect to a purge nozzle for introducing or withdrawing gases from the interior of a substrate container.

Umbrella check valve member115is disposed and held within elastomeric grommet105to engage/disengage valve seat110and thereby restrict or allow fluid flow through check-valve assembly100. Apertures118through internal structure108of grommet105allow fluid flow along the axial length of grommet105.

As illustrated inFIG.7, for example, umbrella check valve member115is oriented such that purge gas or other fluid is allowed to flow out of the substrate container interior, as indicated by arrow125, for egress through check-valve assembly100. Umbrella check valve member115engages valve seat110to disallow fluid flow in an opposite, or ingress, direction. Umbrella check valve member has a stem portion116and a disk portion117.

Internal structure108of grommet105additionally defines second valve seat120, illustrated inFIG.7, on an opposite side of structure108relative to first valve seat110. Orienting umbrella check valve member115within grommet105to engage and disengage valve seat120, instead of valve seat110, permits fluid to flow in a direction opposite to that indicated by arrow125, e.g. for ingress through check-valve assembly100and into the substrate container interior. Umbrella check valve member115then engages valve seat120to disallow fluid flow in an opposite, or egress, direction.

According to one embodiment, stem116of umbrella check valve member115is press-fit into central bore130of grommet105, as viewed inFIG.8, for example, for flow ingress. Alternatively, umbrella check valve member115is press-fit into central bore130from a bottom side of grommet105, again as viewed inFIG.8, for flow egress. Grommet105thus is constructed to retain valve member115in a first position, illustrated inFIG.7, in which valve member115engages and disengages valve seat110to allow fluid flow only in one direction through assembly100, as indicated by arrow125(egress). Grommet105also is constructed to retain valve member115in a second position, e.g. inserted from the top side of grommet105as viewed inFIG.8, to allow fluid flow only in a second direction, opposite to arrow125(ingress). Grommet105, internal structure108, and valve seats110,120, together form a substantially “H”-shaped cross section, as shown inFIG.7.

Grommet105is manufactured by injection molding a thermoplastic elastomer, according to one embodiment, or casting a rubber-like compound such as FKM. Accordingly, grommet internal structure108and valve seats110,120are integrally formed as one-piece with grommet105. Grommet105and seats110,120are elastomeric and have associated elastomeric properties. Umbrella check valve member115is also formed by injection molding the same or similar materials, for example. According to one embodiment, a cracking pressure of umbrella check valve member115is between about 0.5 inches and about 5 inches H2O (between about 0.125 kPa and about 1.25 kPa). Other suitable manufacturing processes for grommet105and valve member115will be apparent to those of ordinary skill in the art upon reading this disclosure.

Forming one or more of umbrella valve member115and valve seats110,120out of elastomeric materials provides a number of advantages, including easy assembly, non-critical relative size, excellent sealing performance, and reduction in the number of parts needed to achieve these advantages. Check-valve assembly100, for example, is formed of just two pieces—elastomeric valve member115and elastomeric grommet105with its internal, integral, elastomeric valve seat(s). Valves and grommets are readily assembled for quick and effective installation, with minimal likelihood of error. One particular size or shape of grommet is not limited to receive one particular size or shape of valve, allowing interchangeability of parts and greater assembly flexibility. Additionally, elastomeric components are less likely to generate particulate contamination, as compared to e.g. metal springs or other components.

Returning toFIG.6, grommet105and its associated valve are sealingly received within purge body housing135. Grommet105optionally includes one or more circumferential protrusions or sealing rings140to seal against the interior surface of purge body housing135. Additionally, filter145is disposed between grommet105and an interior of purge body housing135. Embodiments of filter145and other filters disclosed throughout this patent application include particle filters of suitable technology, such as HEPA filtration or the like. Purge body housing135also optionally includes O-ring150to aid in forming a sealing connection with access structure or receiving structure155associated with a substrate container assembly. Purge body housing135is retained with respect to the substrate container assembly within structure155by retaining clips156, for example, or by other suitable retaining structure. Together, purge body135, grommet105, valve member11, and filter145form a check-valve assembly or module that is easily installable and replaceable in access structures associated with various types of substrate containers.

FIGS.9-11illustrate an additional embodiment of check-valve assembly157, in which grommet158receives housing160, formed of a substantially rigid plastic material, for example. Housing160retains umbrella check valve member162for engagement with valve seats165or170, formed on opposite sides of housing internal structure172, in a manner similar to that described with respect toFIGS.6-8. Internal structure172and valve seats165,170are disposed at a substantial midpoint of housing160along its axial length, and are disposed at a substantial midpoint of grommet158along its axial length, although placement closer to the ends of housing160and grommet158are also contemplated. Forming housing160and valve seats165,170from a substantially rigid material, instead of molding them as an integral part of elastomeric grommet158, provides additional structural resistance to external compressive forces that may act on grommet158, for example. Stem161of valve member is retained in a central aperture163of the valve seat.

Check valve member162is optionally identical to check valve member115of the previously described embodiment, or constructed of different shape or size to fit a particular housing160. As with the previous embodiment, different sizes or shapes of valve member162can be accommodated within housing160, providing greater flexibility in manufacturing and inventory, among other advantages. Housing160defines circumferential protective sidewall175to surround umbrella check valve member162. Housing160with protective sidewall175protects umbrella check valve member162from deformation or other damage that can be caused by external pressure acting upon grommet158, for example upon insertion into access structure or other structure associated with a substrate container. Check-valve assembly157is formed of only three pieces: elastomeric valve member162, housing160, and grommet158. Together, grommet158and housing160with structure172define a substantial “H”-shape in cross section, as shown inFIG.10. Grommet158with housing160and the umbrella check valve member162are together inserted into housing178to form completed check valve module180, all as shown inFIG.11. Check valve module180is readily removably installed in associated retaining or access structure of a suitable substrate container.

One aspect of the disclosure includes retrofitting or replacing an existing check-valve assembly or module with one like that shown inFIGS.6-8orFIGS.9-11. According to one example, shown inFIGS.12-13, check-valve assembly200to be replaced includes purge grommet203, frame205disposed within grommet203, frame205supporting plunger210, spring215, and O-rings220,225, all installed within tubular environmental control structure230(FIG.13) or other access or receiving structure. In the event installation forces, other forces, or normal wear have caused check-valve assembly200to be damaged or otherwise in need of replacement, aspects of the disclosure involve removing assembly200from structure230and replacing it with check-valve module180ofFIGS.9-11or the check valve module ofFIGS.6-8, for example. Alternatively, it is possible to effect repair by removing frame205and its associated components from within purge grommet203, and replacing them with housing160and associated umbrella check valve member162. Purge designs such as those shown inFIGS.12-13potentially risk substrate contamination due to the presence of spring215, in certain conditions, providing additional advantages to replacement in the manner described.

FIG.14shows an additional check-valve module240suitable for use with various substrate containers, according to an embodiment of the disclosure. Module240includes elastomeric umbrella valve member245inserted and retained within a central bore250of valve block255. Filter260and filter cap265are disposed within or at the end of elastomeric or substantially rigid valve block255. Valve block255snaps into or is otherwise retained within valve body270. Interface surface275of valve body270sealingly connects to access or other structure associated with a substrate container. As with previous embodiments, umbrella valve member245can be inserted into bore250in an opposite orientation, i.e. from within valve body255as viewed inFIG.14, to reverse the permissible direction of fluid flow.

As an additional embodiment,FIGS.15-16illustrate check-valve assembly300in unassembled and assembled states, respectively. Assembly300comprises substantially rigid valve seat305that retains elastomeric umbrella check valve member310within central bore315. O-ring320is retained within circumferential groove325of valve seat305to seal valve seat305to surrounding structure. As shown inFIGS.17-18, assembly300is combined with and stacked between purge grommet or other elastomeric interface330, and filter component335, in the form of a filter disc pack, for example, to form a module installed within tubular environmental control structure340. Filter component335abuts against internal stop342of control structure340to prevent over-insertion, according to one embodiment. As with previously described embodiments, the orientation of valve member310with respect to valve seat305, or the orientation of valve member310and valve seat305together with respect to surrounding structure, can be reversed, to reverse the direction of permissible flow through the module.

FIGS.19-24illustrate purge module350, according to another embodiment of the disclosure. Module350includes valve housing355, optionally formed of an elastomeric material and defining valve seats360,365. Elastomeric umbrella check valve member370is received within central bore375of housing355. Filter grate380and filter385are in fluid communication with check valve member370and the remaining components. Housing355and its related components are received within injection molded diaphragm interface390, which itself is received and retained within outer purge body395to form completed module350. In use, optional O-ring400is received within groove405of purge body395and sealingly engages purge body395and module300with respect to surrounding structure.

FIGS.20-21show umbrella check valve member370press-fit into bore375against valve seat360in an outlet configuration, for example, permitting fluid flow with respect to an associated substrate container only in an outward or egress direction.FIG.22shows valve member370press-fit from an opposite end of housing355into central bore375in an inlet configuration, permitting fluid flow with respect to an associated substrate container only in an inward or ingress direction, for example.FIG.23shows assembled module350with umbrella check valve member370installed in an outlet configuration, andFIG.24shows assembled module350with umbrella check valve member370installed in an inlet configuration, according to embodiments of the disclosure.

FIG.25shows module350ofFIG.24installed in forward and reverse configurations with respect to substrate container assembly420. In configuration425, module350serves as a fluid outlet, permitting fluid to flow only away from the interior of substrate container assembly420. In configuration430, module350is inserted into receiving structure of container assembly420in a direction opposite to that of configuration425, causing module350to serve as a fluid inlet and thus permit fluid flow only toward the interior of substrate container assembly420. The two modules350ofFIG.25can be identical or substantially identical in structure but reversed in relation to each other in installation, to permit fluid flow only in opposite directions relative to the substrate container.

In operation, inlet and outlet arrangements disclosed inFIG.25and elsewhere throughout this disclosure can function in concert during a purging activity in which existing air or gas within the interior of the substrate container is displaced by newly introduced air, gas, or other fluid. A vacuum source is optionally coupled to the interior volume of the container by an outlet nozzle that is adapted to interface with a contact surface of an associated valve assembly or module disclosed herein. When force is exerted by the outlet nozzle into an associated elastomeric grommet, the grommet compresses, but maintains its seal against the sealing inner surfaces of associated access or retaining structure of the container, and against the outer surface of valve assembly or module.

As vacuum is coupled with the interior volume of a substrate container, existing fluid in the volume is drawn out of the substrate container through an outlet as described herein, while, while replacement fluid is drawn in through an inlet, including through an associated filter. In a related embodiment, a replacement fluid source is coupled with the interior volume via an inlet nozzle having geometry similar to the outlet nozzle and coupled with an inlet grommet or assembly/module in the same manner in which the outlet nozzle is coupled with the outlet grommet or assembly/module. In another embodiment, no outlet nozzle is used. The inlet nozzle carries pressurized replacement fluid into the interior volume of the container, and displaced fluid simply exists through the outlet arrangement.

Check-valve assemblies and modules according to aspects of the disclosure provide a number of advantages over the prior art. The assemblies and modules are designed to be readily interchangeable, in certain cases, leading to easy repair and replacement of one module/assembly with another. Elastomeric components, as opposed to e.g. metal springs, reduce the risk of contaminants entering the interior of a substrate container. The number of parts within a check-valve assembly is substantially reduced, in some cases to just two pieces: a grommet having internal structure defining one or more valve seats, and an associated umbrella check valve member. Embodiments disclosed herein reduce the possibility of damage to components during installation, reducing the possibility leaking check valves. Embodiments of the disclosure can be used with containers accommodating multiple different substrates and sizes, for example 300 mm and 450 mm silicon wafers. Additionally, check valves according to embodiments of the disclosure are used to control ingress and egress of various gases or other fluids, for example clean dry air, nitrogen, or other suitable purge gas into and out of various microenvironments. Aspects of the disclosure also provide advantages over e.g. duckbill-type check valves disclosed in commonly assigned U.S. Pat. No. 7,201,276, which is incorporated herein by reference. As one example, umbrella valve members disclosed herein are normally or naturally closed, in a flow-obstructing position, whereas a duckbill-type valve needs to be preloaded with pressure in a closed position.

Generally, the various grommets, assemblies, and modules disclosed herein can have the same cross-sectional shape as the receiving structure in which they are disposed, or as the openings that they are designed to seal. For example, in one embodiment, grommets have a generally cylindrical shape with a generally circular cross-section. However, one of ordinary skill in the art will recognize a variety of grommet body geometries, for example tapered geometries, are within the spirit of the present disclosure. In one embodiment, inlet and outlet grommets or inlet and outlet modules disclosed herein are identical parts. Thus, various components of the present disclosure can be used to seal both inlet and outlet openings using the same component elements. In related embodiments, the umbrella check valve members disclosed throughout this application are identical parts. Grommets and modules of the present disclosure further include retaining features for securely holding filters and related components. Thus, the various modules and components described herein can be formed as pre-assembled operational subassemblies. Additional features of grommets, valve members and associates components are disclosed in U.S. Pat. Nos. 8,727,125 and 8,783,463, which are incorporated herein by reference. Additional carriers in which embodiments of the disclosure can be implemented are described in U.S. Pat. No. 6,428,729, which is hereby incorporated by reference.

The grommets, valve members, and other components of the present disclosure can be composed of any material suitable for use in semi-conductor processing applications including polymers and elastomers. In some embodiments, the grommet body and flanges can be composed of a fluoroelastomer. Examples of fluoroelastomers are sold under the trade name Viton® by Dupont Dow Elastomers. Additionally, in some embodiments, the elastomeric grommet body or grommet can have a fluoropolymer, or other inert polymer, coated onto to the surface of the grommet to isolate the elastomeric substance from the interior of the substrate container. Generally, the polymer or fluoropolymer coating should have some flexibility such that the sealing characteristics of the elastomeric grommet body are maintained.

The embodiments described above are intended to be illustrative and not limiting. Additional embodiments are within the claims. Although the present invention has been described with reference to particular embodiments, those skilled in the art will recognize that changes may be made in form and substance without departing from the spirit and scope of the invention.