Abstract:
Filters, methods, and an apparatus for filling housings and both encapsulated porous and non-porous spaces with contaminant control media for placement in electronic enclosures, such as disk drive enclosures, are disclosed. In one embodiment, a filter assembly includes a housing comprising an internal cavity configured to receive contaminant control media, a fill port in communication with the internal cavity, and an opening in communication with the internal cavity, and filter media at least partially covering the opening; and contaminant control media occupying the internal cavity. Contaminant control media is deposited within the internal cavity via the fill port by means of creating a negative pressure within the internal cavity. The application of a partial vacuum facilitates movement of the contaminant control media into the internal cavity and minimizes the contamination of the filter, housing, and work space common to other loose fill filling methods.

Description:
PRIORITY 
     This application is a continuation of U.S. patent application Ser. No. 12/172,244, filed Jul. 13, 2008, issued on Oct. 11, 2011 as U.S. Pat. No. 8,033,304, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/949,840, entitled “CONTAMINANT CONTROL FILTER WITH FILL PORT,” filed Jul. 13, 2007, the contents of which are herein incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a filter construction, an apparatus for making the filter construction, and methods for making the filter construction. 
     BACKGROUND OF THE INVENTION 
     Contaminant control and recirculation filters have a variety of uses, including uses in electronic equipment. In the computer industry, contaminant control and recirculation filters are used within enclosures for electronic devices to protect the electronic components from particulate and gaseous contaminants. For example, disk drives often include contaminant control and recirculation filters within the disk drive enclosure to protect the drive components and the disks from contaminants including water vapor, organic vapor, and out-gassing. Without such protection, these contaminants can lead to stiction, corrosion, and, in some instances, drive failure. 
     Frequently, contaminant control and recirculation filters have either a loose fill contaminant control (see U.S. Pat. No. 6,077,335) or a compression molded contaminant control of various configurations (see, e.g., U.S. Pat. No. 5,876,487 or No. 6,146,446). Each of these configurations offers distinct advantages and disadvantages. A loose fill contaminant control media is generally less expensive than one that is compression molded. However, loose fill contaminant control media is difficult to manipulate due to its granular or beaded nature, and can cause contamination of the clean room, the filter housing, and the surfaces that require welding after deposition of the loose fill contaminant control media. Compression molded contaminant controls are generally easier to handle and are cleaner to use in a clean room environment. However, they are more expensive, require tooling that adds to cost and labor time, and are much less efficient in contaminant adsorption. Clearly, a new filter design which overcomes these challenges would be desirable. 
     SUMMARY OF THE INVENTION 
     Generally, the present invention relates to adsorbent or recirculation filters for placement in an electronic enclosure, such as a hard disk drive, methods of filling these filters with a contaminant control media, and an apparatus capable of accomplishing the filling. 
     In an embodiment, the invention includes a method for filling a filter assembly with a contaminant control media comprising the steps of: providing a housing containing an internal cavity, at least one fill port formed in the housing and in communication with the internal cavity of the housing, and an opening with filter media at least partially covering the opening; providing contaminant control media; creating a negative pressure with the internal cavity by drawing a partial vacuum within the cavity; and drawing the contaminant control media into the internal cavity under partial vacuum. In addition to drawing in the adsorbent, the partial vacuum also prevents dust created during handling the adsorbent or filling the cavity from escaping and contaminating the manufacturing room. The filter media can comprise ePTFE, the contaminant control media can comprise an adsorbent material and neutralization material, and the filter assembly can be configured for insertion into an electronic enclosure. 
     In an embodiment, the invention includes a method for filling a porous filter assembly with a contaminant control media, comprising the steps of: providing a porous container at least partially formed of filter media; providing the contaminant control media; drawing a partial vacuum across the porous container; and drawing the contaminant control media into the porous container under partial vacuum. The filter media can comprise ePTFE and the contaminant control media can comprise an adsorbent material and neutralization material. The porous container can comprise a filter bag or a molded housing and the filter assembly can be configured for insertion into an electronic enclosure. 
     In an embodiment, the invention includes a filter assembly for use in an electronic enclosure including a housing comprising: an internal cavity within the housing, the internal cavity configured to receive contaminant control media, at least one fill port in communication with the internal cavity, an opening in communication with the cavity, and filter media at least partially covering the opening. Contaminant control media occupies the internal cavity. The filter media can comprise ePTFE and the contaminant control media can comprise an adsorbent material and neutralization material. The filter assembly can be configured for insertion into an electronic enclosure. 
     In an embodiment, the invention includes a delivery apparatus comprising: a holding unit configured to retain contaminant control media; an assembly configured to deposit contaminant control media into an encapsulated space; and a device capable of creating a negative pressure within the encapsulated space to facilitate movement of the contaminant control media into the encapsulated space and to prevent the escape of any dust (aerosol) created during the filling. 
     This summary of the present invention is merely an overview of some of the teachings of the present application and is not intended to describe each disclosed embodiment or every implementation of the present invention. Further embodiments will be found in the figures, detailed description, and claims. The scope of the present invention should be determined by the appended claims and their legal equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in connection with the following drawings, in which: 
         FIG. 1  is a perspective view of one embodiment of a filter assembly, according to the invention. 
         FIG. 2  is a top plan view of the filter assembly of  FIG. 1 . 
         FIG. 3  is a bottom plan view of the filter assembly of  FIG. 1 . 
         FIG. 4  is a side elevational view of the filter assembly of  FIG. 1 . 
         FIG. 5  is a schematic cross sectional view of the filter assembly along line A-A′ of  FIG. 2 . 
         FIG. 6  is an inverted cross sectional view of the housing for a filter assembly, prior to being filled with contaminant control media. 
         FIG. 7  is a schematic diagram of an apparatus for loading contaminant control media into a housing for a filter, the apparatus including a source for contaminant control media and a coupling device for applying a vacuum to a surface of the housing. 
         FIG. 8  shows the apparatus for loading contaminant control media of  FIG. 7  along with the housing for a filter assembly of  FIG. 6 , wherein the housing is mounted on the apparatus for loading but before loading the housing with contaminant control media. 
         FIG. 9  shows the apparatus for loading contaminant control media of  FIG. 7  along with the housing for a filter assembly of  FIG. 6 , wherein the housing is partially filled with contaminant control media. 
         FIG. 10  shows the apparatus for loading contaminant control media of  FIG. 7  along with the housing for a filter assembly of  FIG. 6 , wherein the housing is filled with contaminant control media. 
         FIG. 11  shows the housing for a filter assembly of  FIGS. 6 to 10 , after the housing has been removed from the apparatus for loading contaminant control media. 
         FIG. 12A  shows the housing for a filter assembly of  FIGS. 6 to 11 , after a mounting label with release liner has been added and the fill hole in the housing has been closed. 
         FIG. 12B  shows a bottom plan view of the filter assembly of  FIG. 12A . 
         FIG. 13  shows the housing for a filter assembly of  FIGS. 6-12 , wherein the filter assembly has been mounted within an electronic enclosure. 
         FIG. 14A  shows an alternative filter assembly of the invention, wherein the fill hole is configured for use as a breather hole. 
         FIG. 14B  shows a bottom plan view of the filter assembly of  FIG. 14A . 
         FIG. 15A  shows an alternative filter assembly, wherein the fill hole is sealed completely and the filter does not include a breather hole. 
         FIG. 15B  shows a bottom plan view of the filter assembly of  FIG. 15A . 
         FIG. 16A  shows an alternative filter assembly of the invention, wherein the fill hole is positioned along the side of the filter assembly. 
         FIG. 16B  shows a bottom plan view of the filter assembly of  FIG. 16A . 
         FIG. 17A  shows an alternative filter assembly of the invention, wherein filter media is placed on two sides of the filter assembly. 
         FIG. 17B  shows a top plan view of the filter assembly of  FIG. 17A . 
         FIG. 18A  shows an alternative filter assembly of the invention, wherein the filter media and fill port are positioned on the same surface of the filter assembly. 
         FIG. 18B  shows a top plan view of the filter assembly of  FIG. 18A . 
         FIG. 19A  shows an alternative filter assembly of the invention, wherein the filter media and fill port are positioned on the same surface of the filter assembly, further comprising a scrim over the breather port. 
         FIG. 19B  shows a side cross sectional view of a filter assembly including a diffusion channel. 
         FIG. 19C  shows a top plan view of the filter assembly of  FIG. 19A . 
         FIG. 20  shows a top plan view of an alternative filter assembly. 
     
    
    
     While the invention is susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example and drawings, and will be described in detail. It should be understood, however, that the invention is not limited to the particular embodiments described. On the contrary, the intention is to cover modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is applicable to filters and methods of making and using filters to filter a fluid, such as, for example, air or other gases. The filter construction can reduce contaminants within an electronic enclosure, such as a disk drive housing, by a variety of processes. One process for reducing, removing, or preventing contamination within the disk drive housing is to reduce or remove contaminants entering the disk drive housing from regions outside of the disk drive housing (or other device). The breather embodiment of the filter construction is constructed for this purpose. A second process for reducing, removing or preventing contamination from within the disk drive housing is to reduce or remove contaminants present in the disk drive housing atmosphere. The recirculation embodiment of the filter construction, can be constructed for this purpose. In addition, an adsorbent assembly can be used to remove contaminants from the inside of a drive. The adsorbent assembly contains contaminant control media, and is placed within the electronic enclosure, but does not have a recirculation function and does not communicate by a breather hole with the exterior of the enclosure. However, the adsorbent assembly still removes contaminants from the drive interior. 
     In one embodiment, the invention includes a method for filling a filter assembly with a contaminant control media under partial vacuum in a fashion such that the filter assembly is filled with minimal external contamination. In such embodiments the method comprises the steps of providing a housing containing an internal cavity, at least one fill port in communication with the internal cavity, and an opening with filter media at least partially covering said opening. An air flow through the fill hole is created by applying a partial vacuum to the outside of the porous media and this air flow helps draw in the contaminant control media and prevents dust from escaping through the fill hole. The filter media can comprise ePTFE, the contaminant control media can comprise an adsorbent material and neutralization material, and the filter assembly can be configured for insertion into an electronic enclosure. 
     The filter construction generally includes a particulate or solid removal element and a contaminant control element. Examples of particulate or solid removal elements include, but are not limited to, filter materials such as polymers, non-woven materials, fibers, paper, and the like. Examples of contaminant control elements include, but are not limited to, adsorbent material, neutralization material, and the like. Additionally or alternatively, a tortuous or extended path, such as a diffusion channel, can be used to restrict contaminant entry into the electronic enclosure when the filter construction is used as a breather filter. 
     Various aspects of the invention will now be discussed in reference to the figures. Referring to  FIGS. 1 and 2 , one embodiment of the invention includes a filter assembly  10  comprising a housing  40  having a top  20 , base  30 , sidewall  24 , and filter media  50  secured to the top  20 . Although  FIGS. 1 and 2  depict the housing  40  as generally cylindrical in shape, it will be appreciated that various embodiments can include multiple sidewalls defining various shape and sizes of the filter assembly  10 . For example, the housing  40  can be rectangular, oval, square, circular, triangular, or generally any other shape desired. 
     In many applications the housing will be constructed such that it is customized for a specific electronic enclosure, so that it fits within an appropriate portion of the enclosure without interfering with other equipment within the enclosure. For example, when placed within a disk drive assembly, the filter assembly  10  having housing  40  must avoid contact with the spinning disks and read/write head of the disk drive, while also allowing adequate clearance with these moving parts to avoid creating undesirable air turbulence. One of the benefits of the present invention is that it allows a wide variety of shapes and sizes of filter assemblies  10  to be manufactured with minimal retooling for different assembly configurations. 
     Although  FIGS. 1 and 2  depict the filter media  50  as generally a circular shape covering the majority of the top  20 , it will be appreciated that the filter media  50  can be of any shape and can cover different sizes, areas, and dimensions (including one or more sidewall(s) and the base  30 ) of the filter assembly  10 . It will be appreciated that the filter media  50  can be secured with a variety of methods including, but not limited to, mold casting, welding, adhesives, mechanical connections, and the like. 
       FIG. 3  portrays a bottom plan view of the embodiment of the filter assembly shown in  FIGS. 1 and 2 . The base  30  of the filter assembly  10  defines a fill port  60  (indicated by phantom circle). The fill port  60  is used to fill the internal cavity of the housing  40  with contaminant control media  90  (shown in  FIG. 5 ). After the internal cavity of the housing  40  is filled, the fill port  60  can be sealed. In one embodiment of the invention, the fill port  60  is sealed with an adhesive mounting label  70 . 
     The mounting label  70 , serves a dual purpose in the embodiment of the invention shown in  FIGS. 1 ,  2 ,  3 ,  4 , and  5 . The mounting label  70  both seals the fill port  60  and holds the filter assembly  10  in the electronic enclosure. The mounting label  70  can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. In such embodiments the mounting label  70  can both seal the fill port  60  during manufacture and later secure the filter assembly  10  to a mounting surface, such as the interior wall of a hard disk drive. The adhesive carrier is typically a polymer film, such as, for example, a polyethylene, polypropylene, polyester, polycarbonate, polyurethane, or polyvinyl chloride film. Suitable adhesives include, but are not limited to, epoxies, resins, pressure-sensitive adhesives, hot-melt adhesives, solvent-based adhesives, emulsion-based adhesives, and contact adhesives. One example of a suitable adhesive is 3M 502FL adhesive from 3M Co. (St. Paul, Minn.). 
     It will be appreciated that the fill port  60  can also be sealed with a variety of other methods including, but not limited to, snug fit plugs, filter media, ultrasonic welding, and the like. If a mounting label  70  is not used, an additional adhesive media may be necessary. Or, in the alternative, the filter assembly  10  can be held in the electronic enclosure by mechanical techniques, including, but not limited to, clips, frames, welding, or the like. Although  FIG. 3  depicts the fill port  60  as generally a circular shape, it will be appreciated that the fill port  60  can be any shape. 
     Referring again to  FIG. 3 , in the depicted embodiment of the invention the base  30  of the filter assembly  10  defines a breather port  80 . The breather port  80  permits the flow of fluid from the outside of the electronic enclosure into the electronic enclosure. The breather port  80  allows the flow of air to come into contact with the contaminant control media  90  disposed within the internal cavity of the filter housing  40  prior to the flow of air exiting the filter assembly  10 . Although  FIG. 3  depicts the breather port  80  as generally a circular shape, it will be appreciated that the breather port  80  can be of any shape. Also, although not depicted herein, the breather port can be connected to a diffusion channel, molded into the base  70 , formed by one or more thin films, or formed within the surface on which the filter assembly  10  is ultimately mounted (such as the interior wall of a disk drive). 
       FIG. 4  portrays a schematic side view of the embodiment of the invention shown in  FIGS. 1 ,  2 , and  3 . The mounting label  70  can be seen present on the base  30  of one embodiment of the invention. 
       FIG. 5  portrays a cross-sectional view of the embodiment of the invention shown in  FIGS. 1 to 4 , with the cross section taken along line A-A′ of  FIG. 2 . The filter media  50  is secured to the top  20 . The base  30  of the housing  40  defines the fill port  60  that has been sealed by the mounting label  70 , and the base  30  of the housing  40  in conjunction with the mounting label  70  helps further define the breather port  80 . The housing  40  also defines the internal cavity within which the contaminant control media  90  is deposited via the fill port  60 . It will be appreciated that the contaminant control media  90  is of sufficient size, shape, or composition that it is unable to escape through the breather port  60  in the embodiment depicted. Thus, for example, if the breather port is 2 mm in diameter, then it would be desirable to use contaminant control media that is 3 mm in diameter (or at least greater than 2 mm in diameter). In the alternative a scrim or other material can be placed over the interior or exterior of the breather port to prevent escape of the contaminant control media. Further detailed discussion of the contaminant control media can be found below. 
       FIG. 6  portrays an inverted cross sectional view of one embodiment of the invention, prior to filling the housing with contaminant control media. The filter assembly  110  is defined by a housing  140  having a top  120 , base  130 , sidewall  124 , and filter media  150  secured to the top  20 . The base  130  of the housing  140  defines a fill port  160  and a breather port  180 . 
       FIGS. 7-10  portray a schematic diagram, and mechanism of operation, of one embodiment of a filling apparatus capable of loading contaminant control media into the housing of a filter assembly. The filling apparatus  191  includes contaminant control media  190  placed within a loading unit  192 . The filling apparatus  191  further comprises a loading station  194  where the housing  140  for the filter assembly  110  will be placed. The loading station  194  will also be capable of drawing a vacuum across a surface of the housing  140  containing filter media  150  and therefore will further comprise a vacuum generating apparatus. The loading station  194  will further contain a coupling device  196  for attaching the housing  140  to the loading station  194  and for facilitating the creation of a seal sufficient to draw a partial vacuum across a surface of the housing  140  containing filter media  150 . 
       FIG. 8  portrays the filling apparatus  191  where the loading station  194  is occupied by a housing  140  for the filter assembly  110  found in  FIG. 6 . The loading unit  192  is engaged with the housing  140  at the fill port  160  on the base  130  and is capable of depositing the contaminant control media  190  into the internal cavity of the housing  140 . To facilitate delivery of the contaminant control media  190 , a partial vacuum will be drawn across the filter media  150 ; the vacuum generating apparatus being coupled to the loading station  194  and the seal for drawing the vacuum across filter media  150  being facilitated by the coupling device  196  located on the loading station  194 . It will be appreciated that in this embodiment the breather port  180  must be sealed in order to generate the partial vacuum and in this embodiment, the loading unit  192  is capable of sealing the breather port  180 . It will be appreciated that the breather port  180  can also be sealed with any other temporary mechanism, for example, a removable adhesive tape or label. 
       FIG. 9  portrays the loading apparatus loading contaminant control media into the internal cavity of the filter assembly from  FIG. 6 ; the task being partially completed. The application of a partial vacuum facilitates movement of the contaminant control media  190  from the loading unit  192 , through the filler port  160  on the base  130  of the housing  140 , and into the internal cavity of the housing  140  of the filter assembly  110 . A seal sufficient to create a partial vacuum is created by 1) temporarily sealing the breather port  180  and 2) the coupling device  196  of loading unit  194  creating a seal across the filter media  150  of the housing  140 . 
       FIG. 10  portrays the loading apparatus loading contaminant control media into the internal cavity of the filter assembly; the task being completed. The internal cavity of the housing  140  of the filter assembly  110  can be completely and efficiently filled with contaminant control media  190  because of the application of a partial vacuum across the filter media  150  of the housing  140  and the temporary sealing of the breather port  180 . 
     It will be appreciated that  FIGS. 7-10  only represent a single, simplified schematic of the filling apparatus  191  and that various embodiments of the filling apparatus will exist to fill various embodiments of the filter assembly. The general purpose of the filling apparatus is to provide a mechanism to fill the internal cavity of a filter housing with contaminant control media. The contaminant control media is drawn into the internal cavity of the filter housing by drawing a partial vacuum on at least a portion of one surface of the filter housing at least partially covered with secured filter media. 
       FIG. 11  portrays the housing for the filter assembly of  FIGS. 6 to 10  in an inverted position, after the filter assembly has been removed from the loading apparatus. The internal cavity of the housing  140  of filter assembly  110  is completely occupied by the contaminant control media  190  that was loaded via the fill port  160 . It will be appreciated that in this embodiment the contaminant control media  190  is of sufficient size, shape, or composition that is unable to escape the internal cavity of the housing  140  of the filter assembly  110  via the breather port  180 . 
       FIG. 12A  portrays the filter assembly  110  in an upright position after a mounting label has been attached to the base  130  of the housing  140 . The mounting label  170  closes the fill port  160 ; thereby preventing the contaminant control media  190  from escaping the internal cavity of the housing  140 . The mounting label  170  further defines the breather port  180  located on the base  130  of the housing  140  of the filter assembly  110 . The mounting label  170  can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. One adhesive surface can bind to the base  130  of the filter assembly  110  and the second adhesive surface can be protected by a release liner  174 . The release liner  174  can be removed, thereby exposing a second adhesive surface that can be used to secure the filter assembly  110  to an internal surface of an electronic enclosure. 
       FIG. 12B  portrays a bottom plan view of the filter assembly of  FIG. 12A . The base  130  of the housing  140  of the filter assembly  110  defines the breather port  180  and the fill port  160  (indicated by phantom circle). The base  130  is partially covered by a mounting label  170  that can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. The mounting label  170  seals the fill port  160 , while allowing the breather port  180  to maintain fluid communication with the external environment. The mounting label  170  further comprises a release liner  174  that protects the second adhesive surface from environmental exposure. The release liner  174  can be removed, thereby exposing the second adhesive surface that can then be use to secure the filter assembly  110  to an internal surface of an electronic enclosure. It will be appreciated that although the fill port  160  and breather port  180  are depicted as generally circular, they can be of any shape. 
       FIG. 13  portrays the filter assembly of  FIGS. 6-12  where the filter assembly is mounted within an electronic enclosure. The filter assembly  110  is secured within the electronic enclosure  105  via the mounting label  170 . The release liner  174  of  FIG. 12B  had been removed, exposing the second adhesive surface, and said surface is used to secure the filter assembly  110  to the electronic enclosure  105 . The filter assembly  110  is in fluid communication with the external environment via the breather port  180 . It will be appreciated that that contaminant control media  190  is of a sufficient size, shape, or composition that it is unable to escape via the breather port  180 . In this embodiment of the invention, the filter assembly  110  serves as an adsorbent breather filter. 
       FIG. 14A  portrays a schematic cross sectional view of another embodiment of the invention where the fill port is configured for use as the breather port. Thus, the fill port is initially used to fill the housing with contaminant control media, after which the port&#39;s diameter is typically reduced to prevent escape of the contaminant control media, but to still allow the fill port to function as a breather port. In alternative to reducing the diameter of the fill port, it is possible to place a porous media or scrim over the fill port to retain contaminant control media. The internal cavity of the housing  240  of the filter assembly  210  contains the contaminant control media  290 . The contaminant control media  290  is loaded into the internal cavity of the housing  240  via the fill port  260  found on the base  230  of the filter assembly  210 . The housing  240  further comprises a top  220  to which filter media  250  is secured. In this embodiment of the invention, a mounting label  270  is affixed to the base  230  to decrease the diameter of the fill port  260 . 
     The diameter of the fill port  260  should be decreased so that 1) the fill port  260  can be configured into the breather port and 2) the contaminant control media  290  does not escape through the fill port  260 . It will be appreciated that that contaminant control media  290  is of a sufficient size, shape, or composition, that it is unable to escape via the breather port. The mounting label  270  can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. The mounting label  270  will further allow the filter assembly  210  to be secured within an electronic enclosure. 
       FIG. 14B  portrays a bottom plan view of the filter assembly of  FIG. 14A . The base  230  of the filter assembly  210  defines a fill port  260  (indicated by phantom circle). Initially, the fill port  260  is used to fill the internal cavity of the housing  240  with contaminant control media  290 ; later the fill port  260  is configured into the breather port (indicated by the intact circle within the phantom circle that defined the fill port  260 ) by the addition of the mounting label  270 . The mounting label  270  sufficiently decreases the size of the fill port  260  so that the contaminant control media  290  cannot escape. Additionally, the mounting label  270  will allow the filter assembly  210  to be secured within an electronic enclosure. It will be appreciated that although the fill port  260  and breather port are depicted as generally circular, they can be of any shape. In this embodiment of the invention, the filter assembly  210  serves as an adsorbent breather filter. 
       FIG. 15A  portrays another embodiment of the invention where the fill port is completely sealed and there is no breather port. The internal cavity of the housing  340  of the filter assembly  310  contains the contaminant control media  390 . The contaminant control media  390  was loaded into the internal cavity of the housing  340  via the fill port  360  found on the base  330  of the filter assembly  310 . The housing  340  further comprises a top  320  to which filter media  350  is secured. The base  330  is partially covered by a mounting label  370  that can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. The mounting label  370  seals the fill port  360  after the contaminant control media  390  has been loaded into the internal cavity of the housing  340 . The mounting label  370  can further comprise a release liner that protects the second adhesive surface from environmental exposure. The release liner can be removed, thereby exposing the second adhesive surface, and the entire filter assembly  310  can be secured to an internal surface of an electronic enclosure. The assembly of  FIG. 15A  is particularly useful as an adsorbent assembly within an electronic enclosure. 
       FIG. 15B  portrays a bottom plan view of the filter assembly of  FIG. 15A . The base  330  of the filter assembly  310  defines a fill port  360  (indicated by phantom circle). This fill port  360  is used to fill the internal cavity of the housing  340  with contaminant control media  390 . The mounting label  370  is affixed to the base  330  of the filter assembly  310  to seal the fill port  360 . This embodiment of the invention lacks a breather port and therefore can be used as an adsorbent filter. 
       FIG. 16A  portrays another embodiment of the filter assembly where the fill port is positioned on a side wall of the filter assembly. The internal cavity of the housing  440  of the filter assembly  410  contains the contaminant control media  490 . The contaminant control media  490  was loaded into the internal cavity of the housing  440  via the fill port  460  found on the sidewall  424  of the filter assembly  410 . The housing  440  further comprises a top  420  to which filter media  450  is secured. 
     The base  430  is partially covered by a mounting label  470  that can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. The mounting label  470  is used to secure the filter assembly  410  to a mounting surface, such as the interior surface of an electronic enclosure. The fill port  460  can be sealed with an adhesive label  464  and can be, for example, a single sided adhesive film that includes an adhesive carrier with adhesive disposed on a single side. In an alternative embodiment, the fill port  460  can be designed so that it can be sealed with tight fitting plug. 
       FIG. 16B  portrays a bottom plan view of the filter assembly of  FIG. 16A . To the base  430  of the housing  440  of the filter assembly  410  is affixed a mounting label  470 . The mounting label  470  can further comprise a release liner that protects the second adhesive surface from environmental exposure. The release liner can be removed, thereby exposing the second adhesive surface, and the entire filter assembly  410  can be secured to an internal surface of an electronic enclosure. On the sidewall  424  of the housing  440  is the fill port  460  of  FIG. 16A  that can be sealed with an adhesive label  464 . It will be appreciated that although the filter assembly  410  in this embodiment is cubical in shape, the filter assembly  410  can be of any shape. This embodiment of the invention lacks a breather port and therefore can be used as an adsorbent filter. 
       FIG. 17A  portrays another embodiment of the invention where filter media is secured to two dimensions of the filter assembly. The internal cavity of the housing  540  of the filter assembly  510  contains the contaminant control media  590 . The contaminant control media  590  was loaded into the internal cavity of the housing  540  via the fill port  560  found on the sidewall  524  of the filter assembly  510 . The housing  540  further comprises a top  520  and base  530  to which filter media  550  is secured. It will be appreciated that the filter media  550  can be secured with a variety of methods including, but not limited to, mold casting, welding, adhesives, mechanical connections, and the like. It will be further appreciated that the filter assembly  510  can be held in the electronic enclosure by mechanical techniques, including, but not limited to, clips, frames, welding, or the like. The fill port  560  can be sealed with an adhesive label  564  that can be, for example, a single sided adhesive film that includes an adhesive carrier with adhesive disposed on a single side. In an alternative embodiment, the fill port  560  can be designed so that it can be sealed with tight fitting plug. 
       FIG. 17B  portrays a top plan view of the filter assembly of  FIG. 17A . The top  520  of the housing  540  of the filter assembly  510  partially comprises secured filter media  550 . The fill port  560  of  FIG. 17A  located on sidewall  424  is sealed with an adhesive label  464 . It will be appreciated that although the filter assembly  510  in this embodiment is cubical in shape, the filter assembly  410  can be of any shape. This embodiment of the invention lacks a breather port and therefore can be used as an adsorbent filter. 
       FIG. 18A  portrays another embodiment of the invention where the secured filter media and the fill port are located on the same surface of the filter assembly. The internal cavity of the housing  640  of the filter assembly  610  contains the contaminant control media  690 . The contaminant control media  690  was loaded into the internal cavity of the housing  640  via the fill port  660  found on the same surface upon which the secured filter media  650  is positioned. The fill port  660 , in  FIG. 18A , is shown “unsealed”. A weld horn, in conjunction with ultrasonic welding, can be used on the protrusions  664  of the fill port  660  to seal the filter assembly  610 . The housing  640  further comprises a top  620  to which filter media  650  is secured and a base  630  that defines a breather port  680 . The breather port is further defined by a mounting label  670 . The base  630  is partially covered by a mounting label  670  that can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. The mounting label  670  is used to secure the filter assembly  610  to a mounting surface, such as the interior surface of an electronic enclosure. 
       FIG. 18B  portrays a top plan view of the filter assembly of  FIG. 18A . The top  620  of the housing  640  of the filter assembly  610  partially comprises secured filter media  650 . The fill port  660  of  FIG. 18A  located on the top  620  and has been sealed with a weld horn in conjunction with ultrasonic welding. It will be appreciated that although the filter assembly  610  in this embodiment is generally oval in shape, the filter assembly  610  can be of any shape. This embodiment of the invention can be used as a breather adsorbent filter. 
       FIG. 19A  portrays another embodiment of the invention where the secured filter media and the fill port are located on the same surface of the filter assembly and a scrim that covers the breather port is located within the internal cavity of the housing. The internal cavity of the housing  740  of the filter assembly  710  contains the contaminant control media  790 . The contaminant control media  790  was loaded into the internal cavity of the housing  740  via the fill port  760  found on the same surface upon which the secured filter media  750  is positioned. The fill port  760  can be sealed with an adhesive label  764  that can be, for example, a single sided adhesive film that includes an adhesive carrier with adhesive disposed on a single side. 
     In an alternative embodiment, the fill port  760  can be designed so that it can be sealed with tight fitting plug. The housing  740  further comprises a top  720  to which filter media  750  is secured and a base  730  that defines a breather port  780 . The breather port is further defined by a mounting label  770 . The base  730  is partially covered by a mounting label  770  that can be, for example, a double-sided adhesive film that includes an adhesive carrier with adhesive disposed on both sides. The mounting label  770  is used to secure the filter assembly  710  to a mounting surface, such as the interior surface of an electronic enclosure. Within the housing  740 , adjacent to the base  730 , and above the breather port  780 , is placed a scrim  752 . This scrim  752  can be composed of similar material as the filter media  750  and the scrim  752  can function to filter the incoming fluid or prevent the contaminant control media  790  from escaping through the breather port  780 . 
     In the embodiment portrayed in  FIG. 19B , the scrim  752  defines a diffusion channel  756  and a breather port  780 . The diffusion channel  756  provides a tortuous or extended path that can be used to restrict contaminant entry into the electronic enclosure. The diffusion channel  756  can be formed as a straight or curved path. Alternatively, the diffusion channel  756  may be formed to have a more complex path, such as a winding path or a spiral path. For example, the diffusion channel can be configured as an inwardly spiraling channel, an outwardly spiraling channel, or as a maze-like configuration. The diffusion channel  756  can, in some embodiments, have two or more branches. 
     Examples of diffusion channels for use with computer disk drive systems are described in U.S. Pat. No. 4,863,499, incorporated herein by reference. Other examples of a diffusion channels defined by diffusion channel layer of film are described in U.S. Pat. No. 5,997,614, incorporated herein by reference. Fluid enters the breather port  780 , travels through diffusion channel  756 , and then enters the internal cavity of the filter housing  740 . Fluid can also travel through this pathway in the reverse direction depending on relative air pressure. 
     Referring again to  FIG. 19B , the base  730  includes a scrim  752 . The scrim  752  defines the diffusion channel  756 . The boundary layer  754  can be formed using a polymer or metallic film or a plastic layer. The boundary layer  754  is typically nonporous and has a low permeability to the fluid to be filtered, particularly, at the fluid pressures expected for operation of the filter assembly  710 . Examples of suitable polymer films for use in the boundary layer  754  include polyester (e.g., Mylar), polyethylene, polypropylene, nylon, polycarbonate, polyvinyl chloride, and polyvinyl acetate films. Preferably, the polymer films have relatively low or no out-gassing. Suitable metallic films for use in the diffusion boundary layer  754  include films formed using metals, such as, for example, copper and aluminum, and alloys, such as, for example, stainless steel. Preferred metal films do not significantly corrode or form reaction products (e.g., rust) that can be dislodged from the film under the expected operating conditions of the filter. In some embodiments, the metallic film may be deposited or otherwise formed on a base material, such as, for example, a polymer film. 
       FIG. 19C  portrays a top plan view of the filter assemblies of  FIGS. 19A and 19B . The top  720  of the housing  740  of the filter assembly  710  partially comprises secured filter media  750 . The fill port  760  can be sealed with an adhesive label  764  that can be, for example, a single sided adhesive film that includes an adhesive carrier with adhesive disposed on a single side. In an alternative embodiment, the fill port  760  can be designed so that it can be sealed with tight fitting plug. It will be appreciated that although the filter assembly  710  in this embodiment is generally oval in shape, the filter assembly  710  can be of any shape. This embodiment of the invention can be used as a breather adsorbent filter. 
       FIG. 20  portrays a top plan view of another embodiment of the invention. Arrows show fluid entering the filter assembly  810  through one secured filter media  850  and exiting the filter assembly  810  housing  840  through a second secured filter media  850 . The housing  840  further defines a top  820  upon which a fill port  860  is located; the fill port  860  being used to deposit contaminant control media within the internal cavity of the housing  840 . In alternative embodiments, the fill port  860  can be located on the base or the sidewall of the housing  840 . The fill port  860  can be sealed with an adhesive label  864  that can be, for example, a single sided adhesive film that includes an adhesive carrier with adhesive disposed on a single side. In an alternative embodiment, the fill port  860  can be designed so that it can be sealed with tight fitting plug. In this embodiment, the invention can be used as a recirculation filter. 
     In an alternative embodiment of  FIG. 20 , the invention further comprises a base that can define a breather port that is in fluid communication with both the internal cavity of the housing of the filter assembly and the external environment. In this embodiment, the invention can be used as a breather recirculation filter. In an alternative embodiment of  FIG. 20 , the invention further comprises a breather port and diffusion channel. In this embodiment, the invention can be used as a breather recirculation filter. 
     Contaminant Control Material 
     Typically, the contaminant control media is disposed within the internal cavity of the housing or within a porous or non-porous encapsulated space. The contaminant material can be any suitable material for the removal, reduction, entrapment, immobilization, adsorption, absorption, and neutralization of contaminants. 
     The contaminant control media is typically provided for the removal of chemical contaminants. The contaminant control media can remove contaminants from the air entering the enclosure atmosphere or already present within the enclosure atmosphere by adsorption, neutralization, or immobilization. As used throughout this application, the terms “adsorb,” “adsorption,” “adsorbent” and the like, are intended to also include the mechanism of absorption. Typically, the contaminant control media is selected to be stable and adsorb or neutralize contaminants within normal disk drive operating temperatures, for example, within a range of about −40° C. to 100° C. 
     The contaminant control media adsorbs or neutralizes one or more types of contaminants, including, for example, water, water vapor, acid gas, and volatile organic compounds. The contaminant control media can include adsorbent material (physisorbent or chemisorbent material), such as, for example, a desiccant (i.e., a material that adsorbs or absorbs water or water vapor) or a material that adsorbs or absorbs volatile organic compounds, acid gas, or both. Suitable adsorbent materials include, for example, activated carbon, activated alumina, molecular sieves, silica gels, potassium permanganate, calcium carbonate, potassium carbonate, sodium carbonate, calcium sulfate, or mixtures thereof. Carbon is suitable for most implementations, and carbon suitable for use with the present invention is disclosed in U.S. Pat. No. 6,077,335, incorporated herein by reference in its entirety. 
     Additionally, contaminant control media can include neutralization material. Neutralization material can include acid or base impregnated substances that can effectively neutralize the gaseous contaminants found within the housing or electronic enclosure. Neutralization material can also include enzyme or catalyst impregnated substances that increase the rate of degradation of the gaseous contaminants found with the housing or electronic enclosure. 
     Although contaminant control media can be manufactured from a single substance, mixtures of materials are also useful, for example, silica gel can be blended with carbon particles. In some embodiments, the contaminant control media includes layers or combinations of materials, so that different contaminants are selectively removed as they pass through or by the different materials. 
     It will be appreciated that, contaminant control media can undertake many forms including powdered (passes through 100 mesh), granular (passes through 28 to 200 mesh), beads, slurry, paste and any combination thereof. 
     Filter Media 
     Filter media of the present invention may contain one or more particulate filter layers to prevent particulate contaminants from entering the electronic enclosure from the filter assembly. Such particulate contaminants may originate outside of the electronic enclosure or may be shed from the contaminant control media. Filters of the present invention may also include particulate filter layers to prevent particulate contaminants from entering the filter assembly from outside of the electronic enclosure. They may be disposed on the outside of the filter assembly or disposed inside of the filter assembly. 
     The filter media may comprise a variety of porous or microporous membranes. The size of the pores in the membranes and the thickness of the membranes often determine, at least in part, the size of particles allowed through the membrane and filter. 
     Often the porous or microporous membranes are formed from polymers. Examples of suitable porous or microporous membranes include porous or microporous polyethylene, polypropylene, nylon, polycarbonate, polyester, polyvinyl chloride, polytetrafluoroethylene (PTFE), and other polymeric membranes. An especially suitable filtering layer is expanded polytetrafluoroethylene (ePTFE) because of its good filtration performance, conformability to cover adsorbent layers, and cleanliness. A preferred ePTFE membrane has a filtration efficiency of 99.99% at 0.1 micrometer diameter sized particles with a resistance to airflow of approximately 20 mm water column at an airflow of 10.5 feet per minute face velocity. ePTFE is commercially available under the registered trademark GORE-TEX by W. L. Gore &amp; Associates, Inc. 
     In one embodiment, the filter assembly is shown with a porous support layer disposed within the internal cavity of the filter housing. The contaminant control media is disposed on the porous support layer. For example, a mesh or scrim can be used as the porous support layer to hold the contaminant control media. Polyester and other suitable materials (such as polypropylene, polyethylene, nylon and PTFE) can be used as the mesh or scrim. The porous support layer can be used as a base on which the adsorbent media is disposed. 
     Typically, any porous support layer is not more than about 40% of the weight of the adsorbent material, and is generally about 10 to 20% of the total filter media weight. 
     Filter Housing 
     The filter housing may be, for example, an outer covering, a casing, or a shell. The housing is typically formed from a plastic material, such as, for example, polycarbonate, polyvinyl chloride, nylon, polyethylene, polypropylene, or polyethylene terephthalate. The housing may be a single piece or, alternatively, the housing may be formed as two or more pieces that are combined together using, for example, an adhesive, mechanical connectors, heat sealing, and ultrasonic welding to form, for example, a perimeter seal. 
     It should be noted that in the context of this invention the reference to the “reduction” or “removal” of contaminants refers to the clarification of a fluid (e.g., gas or liquid) being filtered. The fluid being clarified in a hard disk drive enclosure is typically an air stream. It should be appreciated, however, that streams of other gases or liquids could also be clarified by the filter construction of the present invention. The reduction or removal of contaminants from a liquid or gas stream by a filter construction can also be referred to as entrapment, immobilization, adsorption, absorption, neutralization, or otherwise binding (e.g., by covalent, ionic, coordinative, hydrogen, or Van der Waals bonds, or combinations thereof) of the contaminants inside or on the surface of the filter construction. 
     It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     All publications and patent applications in this specification are indicative of the level of ordinary skill in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated by reference. 
     This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.