Abstract:
A faceplate for AMC carriers is fabricated from extruded aluminum using a combination of extruded cross-sectional features and machined features to achieve the structural and functional characteristics of an AdvancedTCA faceplate. The extruded aluminum faceplate significantly improves on sheet-metal alternatives while substantially conforming to the AdvancedTCA specification.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. App. No. 60/941,237 filed on May 31, 2007, the entire content of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Enclosures are commonly used to house electronic components, devices, cards, and the like for use in larger electronic systems. The Peripheral Component Interconnect (“PCI”) Industry Manufacturing Group (“PICMG”) has ratified the PICMG 3.0 specification, also referred to as AdvancedTCA, along with a number of sub-specifications in order to standardize enclosures for applications such as high-performance telecommunications and industrial computing. Further standardization is provided by Advanced Mezzanine Card (“AMC”) specifications, a family of printed circuit board specifications targeted to requirements for the next generation of carrier grade telecommunications equipment. The AMC specifications define standards for hot-swappable, field-replaceable mezzanine cards intended for use with AdvancedTCA (“ATCA”) card carriers. Among other things, the PICMG 3.0 specification defines a faceplate for the front of these ATCA-compliant, AMC card carriers. 
         [0003]    Faceplate standardization permits vendors to independently design and manufacture conforming parts. The AdvancedTCA faceplate specifications have been specifically developed with an eye toward sheet metal in order to support low-cost, high-volume manufacturing. The specification recommends a consistent one millimeter thickness in order to maintain a uniform look and feel among manufacturers, and explicitly discourages use of any internal surfaces extending beyond a “front board attachment plane” that extends another one millimeter into the carrier interior. Thus, while AdvancedTCA does not strictly require use of sheet metal, to date the commercially-available alternatives employ some form of shaped and/or stamped sheet metal. This may be due to the relative simplicity and low cost of sheet metal fabrication. However, another significant contributor is the tight physical constraints placed on the faceplate form factor by the AdvancedTCA specification. 
         [0004]    While incremental uses of extruded material have been proposed, such as corner extrusions for an ATCA chassis, there remains a need for alternative techniques to fabricate AMC carrier faceplates for use in AdvancedTCA enclosures. 
       SUMMARY 
       [0005]    A faceplate for AMC carriers is fabricated from extruded aluminum using a combination of extruded cross-sectional features and machined features to achieve the structural and functional characteristics of an AdvancedTCA faceplate. The extruded aluminum faceplate significantly improves on sheet-metal alternatives while substantially conforming to the AdvancedTCA specification. 
         [0006]    In one aspect, an extruded faceplate described herein includes an extruded material having a length sized for use as a faceplate for an AMC carrier, the extruded material having a front side that forms an outside surface of the AMC carrier and a rear side that forms an interior surface of the AMC carrier; the extruded material having a cross-sectional shape including a channel on the front side, the channel including a depressed, substantially planar surface sized for an adhesive overlay and the channel including two raised edges that confine the adhesive overlay to the channel; and the extruded material having at least one machined feature adapted for assembly into the AMC carrier. 
         [0007]    The channel may have a depth substantially equal to a thickness of the adhesive overlay. The extruded faceplate may include at least one through-hole from the planar surface of the channel to the rear side of the extruded faceplate, the at least one through-hole shaped and sized for a light emitting diode. The extruded faceplate may include at least one through-hole from the planar surface of the channel to the rear side of the extruded faceplate, the at least one through-hole shaped and sized for at least one of a button, a switch, and a dial. The extruded faceplate may include an opening from the front side to the rear side, the opening shaped and sized to receive an ejector. The faceplate may include the adhesive overlay adhered to the channel. 
         [0008]    In another aspect, there is disclosed herein an extruded material having a length sized for use as a faceplate for an AMC carrier, the extruded material having a front side that forms an outside surface of the AMC carrier and a rear side that forms an interior surface of the AMC carrier; the extruded material having a cross-sectional shape including a channel between the front side and the rear side, the channel including a depressed, substantially planar surface sized for an adhesive strip of EMI shield material; and the extruded material having at least one machined feature adapted for assembly into the AMC carrier. 
         [0009]    The channel may be positioned to support the adhesive strip in a location where the AMC carrier physically mates with a chassis. The channel may be positioned to support the adhesive strip in a location where the AMC carrier physically mates with another faceplate. The channel may be substantially perpendicular to the front side and the rear side. The channel may include two raised edges that confine the adhesive strip to the channel. The extruded faceplate may include the adhesive strip of EMI shield material adhered to the channel. 
         [0010]    In another aspect, an extruded faceplate disclosed herein includes an extruded material having a length sized for use as a faceplate for an AMC carrier, the extruded material having a front side that forms an outside surface of the AMC carrier and a rear side that forms an interior surface of the AMC carrier; the extruded material having a cross-sectional shape including a tapered edge extending rearward from and substantially perpendicular to the rear surface; and the extruded material having at least one machined feature adapted for assembly into the AMC carrier. 
         [0011]    The tapered edge may include at least one tapered side to facilitate insertion of the AMC carrier into a chassis. The tapered edge may include a taper to facilitate attachment to a plurality of offset fingers extending from a sheet metal carrier cover. The extruded faceplate may include the sheet metal carrier cover, the sheet metal carrier cover attached to the extruded faceplate with at least two of the offset fingers on each side of the tapered edge. 
         [0012]    In another aspect, an extruded faceplate as disclosed herein includes an extruded material having a length sized for use as a faceplate for an AMC carrier, the extruded material having a front side that forms an outside surface of the AMC carrier and a rear side that forms an interior surface of the AMC carrier; the extruded material having a cross-sectional shape including at least one profile feature adapted for assembly into the AMC carrier; and the extruded material having an opening machined therein extending from the front surface to the rear surface, the opening shaped and sized to receive an AMC module and the opening including a beveled edge oriented to guide insertion of the AMC module into the opening through the front surface. 
         [0013]    The extruded faceplate may include at least one notch formed in an edge extending rearward from the rear surface, the notch providing two opposing lateral supports for a card guide positioned behind the extruded faceplate. The extruded faceplate may include an attachment leg extruded into the cross-sectional shape and extending rearward from the rear surface, the attachment leg adapted to secure a card guide strut in a position to support a carrier cover. 
         [0014]    In another aspect, a card carrier disclosed herein includes a faceplate formed of an extruded material having a length sized for use in an AMC carrier, the faceplate having a front side that forms an outside surface of the AMC carrier and a rear side that forms an interior surface of the AMC carrier, the front side and the rear side connected by a top edge and a bottom edge to form a cross-sectional shape including at least one profile feature adapted for assembly into the AMC carrier, the extruded material further including at least one machined feature adapted for assembly into the AMC carrier, the faceplate forming a front of the card carrier; a first carrier cover formed of sheet metal and removably and replaceably attached to the top edge of the faceplate, the first carrier cover forming a top of the card carrier; a second carrier cover formed of sheet metal and removably and replaceably attached to the bottom edge of the faceplate, the second carrier cover forming a bottom of the card carrier; and a plurality of card guides interconnecting the first carrier cover and the faceplate, wherein adjacent ones of the plurality of card guides provide a pair of aligned rails for receiving and supporting one or more AMC cards. 
         [0015]    The card carrier may include at least one card connecter including an edge connecter aligned with the pair of aligned rails and adapted to physically and electronically connect to the one or more AMC cards, the card connecter removably and replaceably connected to the first carrier cover and the second carrier cover. The card carrier may include an ejector positioned within a machined opening in the faceplate and positioned to permit user access from the front side of the faceplate. The card carrier may include a power connector affixed to the second carrier cover, the power connector providing an interconnect between an external power supply and one or more electronic components within the carrier. The card carrier may include a plurality of threaded inserts pressed into at least one of the first carrier cover and the second carrier cover. The card carrier may include a plurality of disposable standoffs removably positioned between the first carrier cover and the second carrier cover, the disposable standoffs maintaining a substantially fixed relationship between the first carrier cover and the second carrier cover. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0016]    The invention and the following detailed description of certain embodiments thereof may be understood by reference to the following figures: 
           [0017]      FIG. 1  is an exploded view of an AMC carrier including a faceplate. 
           [0018]      FIG. 2  is a side view of an extruded faceplate. 
           [0019]      FIG. 3  is a front view of an extruded faceplate. 
           [0020]      FIG. 4  is a rear view of an extruded faceplate. 
           [0021]      FIG. 5  is a top view of an extruded faceplate. 
           [0022]      FIG. 6  is a bottom view of an extruded faceplate. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    An extruded faceplate is described for use with AMC carriers. It while be understood that the carriers described herein may be referred to as AMC carriers in reference to the type of module carried, or as ATCA carriers in reference to the specification to which the carrier itself conforms. These carrier types are neither mutually exclusive nor mutually inclusive, and unless otherwise specified or clear from the context, general references to a carrier are intended to refer to either type of carrier or both. The principles of the invention may be suitably adapted to either type of carrier without departing from the scope and spirit of this disclosure. 
         [0024]    It will be understood that the term chassis as used herein, refers to any ATCA chassis which may include a chassis having 2 slots, 5 slots, or 14 slots, as well as a chassis in a rack mount or a stand-alone form factor, and a chassis that receives carriers vertically or horizontally. A chassis may also or instead include any other chassis or hardware designed to receive a number of card carriers and connect them to an electrical system. A wide range of ATCA chassis and other chassis are readily commercially available. 
         [0025]      FIG. 1  is an exploded view of an AMC carrier including a faceplate. In general, a carrier  100  is formed from a faceplate  102 , a top carrier cover  104 , a bottom carrier cover  106 , and a number of card guides  108  positioned to receive printed circuit boards and the like. A number of machine screws  110 , threaded inserts  112 , alignment pins, and the like may be used to secure the covers  104 ,  106 , card guides  108 , faceplate  102 , and other components together into an assembled unit. 
         [0026]    The faceplate  102  may be fashioned by extrusion of aluminum or any other suitable material or mixture of materials capable of extrusion. By way of example and not of limitation, suitable aluminum alloys include International Alloy Designation System numbers 6005-T6, 6061-T6, 6063-T5 and the like. Various features of the faceplate  102  are more specifically described below with reference to  FIGS. 2-6 . A number of specific components connected to the faceplate  102  are explained briefly here in the context of the entire carrier  100 . 
         [0027]    An adhesive overlay  116  may be affixed to the faceplate  102 . The adhesive overlay  116  may have an adhesive back surface including any type of adhesive suitable for temporarily, permanently, or semi-permanently attaching the adhesive overlay  116  to the faceplate. A front surface of the adhesive overlay  116  may contain any desired visual information including company logos, graphics, product names or descriptions, indicator light labels, and so forth. The adhesive overlay  116  may be fabricated from any suitable plastic, rubber, metal film, or other material or combination of materials. The adhesive overlay  116  may include cutouts for through-holes such as for a captive screw  117  in the faceplate  102 , notches on the edges or corners, such as for an ejector  118 , and any number of translucent or transparent regions to permit light-emitting diodes (LEDs) or the like to emit light through the adhesive overlay  116 . 
         [0028]    One or more ejectors  118  may be provided that assist in removing or “ejecting” the carrier  100  from a chassis, more generally permitting user access to the carrier  100  from a front (or exterior) side of the faceplate  102 , or more generally, from the front side of a chassis that houses the carrier  100 . A number of types of ejectors suitable for use with a card carrier are known in the art and may be used with a carrier  100  as described herein. In standards-based carriers such as ATCA carriers, the faceplate  102  may include a standards-defined opening for the ejectors  118 . The ejectors  118  may be positioned within a machined opening in the faceplate  102  as described in greater detail below. 
         [0029]    An electromagnetic interference (“EMI”) gasket  120  or other grounded shielding or the like may be coupled to the faceplate  102 , such as along a bottom edge thereof. The EMI gasket  120  may be an adhesive strip of EMI shield material having an adhesive backing for adhering to the faceplate  102  in an appropriate location. The EMI gasket may more generally be any suitable shielding material. In one embodiment, the EMI gasket  120  is formed of 4E06-AD-51K EMI shield gasket stripping commercially available from Laird Technologies. 
         [0030]    The top carrier cover  104 , also referred to in AdvancedTCA as the Carrier Side  1  or CS 1  cover, may be removably and replaceably attached to a top edge of the faceplate  102  to form a top of the carrier  100 . The top carrier cover  104  may include any number of holes  122  for mounting screws  112 , threaded inserts  112 , and so forth. Threaded inserts  112 , for example, may be pressed into the inner surface or through the outer surface of either or both of the covers  104 ,  106  to align card guides  108  and the like during assembly of the carrier  100 . A cover is typically although not necessarily fabricated from sheet metal of adequate thickness and strength for the intended use of the carrier  100 . 
         [0031]    The bottom carrier cover  106 , also referred to in AdvancedTCA as the Carrier Side  2  or CS 2  cover, may be removably and replaceably attached to a bottom edge of the faceplate  102  to form a bottom of the carrier  100 . The bottom carrier cover  106  may include any number of holes  124  for mounting screws, and so forth. In general, holes may be pre-drilled in the bottom carrier cover  106  (and the top carrier cover  104 ) in predetermined locations according to a modular architecture for cards, card guides, and the like, or in application-specific locations for a power supply, disposable standoffs  126  (described below), or any other general or specific use. In order to more securely affix the bottom carrier cover  106  to the faceplate  102 , offset fingers  128  may extend from the bottom carrier cover  106  in pairs (as shown), triplets, or other groupings. The offset fingers  128  may, for example, mate with a tapered edge (see  FIG. 2 ) of the faceplate  102  such that the offset fingers  128  rest on either side of the tapered edge. In one embodiment, the cover may include six offset fingers  128  which alternate between a top and a bottom side of the tapered edge. The offset fingers  128  may be stamped into the sheet metal of the bottom carrier cover  106 , or otherwise formed as an integral part of, or connected to, the cover. It will be understood that numerous variations to the number, position, and manufacture of offset fingers  128  are possible and are intended to fall within the scope of this description. 
         [0032]    The card guides  108  may interconnect the top carrier cover  104  and the bottom carrier cover  106 , with adjacent card guides  108  providing a pair of aligned rails for receiving and supporting a card or module such as an AMC card. In addition to aligning a card with a rear edge connector within the carrier  100 , the card guides  108  may provide grounding, shielding, as well as mechanical features such as vibration damping or a locking mechanism to secure a card in a slot. 
         [0033]    Although not depicted in  FIG. 1 , it will be understood that an assembled carrier  100  generally includes card connectors or the like for cards such as AMC cards that are inserted along the aligned rails of the card guides  108 . The connectors, which may be edge connectors or the like, are generally aligned with the rails of the card guides  108  such that a card or circuit board inserted along the rails is physically and electronically connected with the carrier  100  and thus to any electronic system coupled to the carrier  100  through a backplane or the like. Each card connector may be removably and replaceably attached to the carrier covers  104 ,  108  using screws or the like. This mechanical connection, typically toward the rear of the carrier  100 , also serves to strengthen the overall structure of the carrier  100  in combination with the faceplate  102  and other components. It will be understood that card carriers generally, and AMC or ATCA carriers in particular, may include additional components not shown in  FIG. 1 . For example, the carrier  100  may include a power connector affixed to one of the carrier covers  104 ,  108  to provide an interconnect between an external power supply and one or more electronic components within the carrier  100 , or the carrier  100  may include a cooling or ventilation system suited to any electronics intended for use within the carrier  100 . 
         [0034]    In order to preserve the structural integrity of partially assembled carriers (e.g., carriers without card connectors or other components) during shipping and handling, disposable standoffs  126  made of nylon or any other suitable material may be secured between the carrier covers  104 ,  108  in various locations such as along a rear edge of the top carrier cover  104 . In this position, the disposable standoffs  114  can maintain a substantially fixed physical relationship between the top carrier cover  104  and the bottom carrier cover  106 . 
         [0035]      FIG. 2  is a side view of an extruded faceplate. The faceplate  200 , which may be for example the faceplate  102  described above with reference to  FIG. 1 , generally has a cross-sectional shape formed along its length during an extrusion process. Thus it will be understood that an extrusion shape or profile for the faceplate  200  is generally the same as the cross-sectional shape of the faceplate  200  but for any material changes during cooling or other artifacts of a particular extrusion process. Oriented relative to an AMC carrier (or any other carrier described above) of which it may form a part, the faceplate  200  has a front side  202  that forms an outside surface of the AMC carrier and a rear side  204  that forms an inside surface of the AMC carrier. The cross-sectional shape of the faceplate  200  may include a number of extruded features that provide structural and/or functional support to use in a card carrier. 
         [0036]    The cross-sectional shape may include a channel  206  on the front side  202  of the faceplate  200  for confining an adhesive overlay (not shown) such as the adhesive overlay  116  described above in a desired location. The channel  206  may include a substantially planar surface  208  sized for the adhesive overlay. In this respect it will be understood that sized for an adhesive overlay means at least as wide from edge  210  to edge  212 ) as the overlay, and possibly wider than the overlay, with a length determined by the length at which the extrusion is cut rather than any feature of the cross-sectional shape. The channel  206  may include two raised edges  210 ,  212  that confine the adhesive overlay within the channel  206 , which may assist in placement of the overlay and serve to retain the overlay in its position during regular use. In general, the adhesive overlay may be thinner than the channel so that its outer surface lies below the outermost portion of the raised edges  210 ,  212 , or substantially equal to the thickness (i.e., depth) of the channel to provide a flush surface, or thicker than the overlay. By making the raised edges  210 ,  212  equal to or greater than the thickness of an adhesive overlay, the overlay can be advantageously protected from de-adhesion along its edges during use and handling of the faceplate  200 . 
         [0037]    The cross-sectional shape may also or instead include a channel  212  on a bottom surface of the faceplate  200 , or between the front side  202  and the rear side  204 , for confining an adhesive strip of EMI shield material (not shown) such as the EMI gasket  120  described above in a desired location. The channel  212  may be substantially perpendicular to the front side  202  and the rear side  204  as shown in  FIG. 2 . The channel  212  may include a substantially planar surface  214  sized for the adhesive strip of EMI shield material. In this respect it will be understood that sized for an adhesive strip means at least as wide (from edge  216  to edge  218 ) as the adhesive strip, and possibly wider than the adhesive strip, with a length determined by the length at which the extrusion is cut rather than any feature of the cross-sectional shape. The channel  212  may include two raised edges  216 ,  218  that confine the adhesive strip within the channel  212 , which may assist in placement of the adhesive strip and serve to retain the adhesive strip in its position during regular use. In general although not exclusively, the adhesive strip is substantially thicker than the depth of the channel so that the shielding material can come into secure contact with an edge of a chassis or the like into which the carrier is inserted. More specifically, the channel  212  may be positioned to support the adhesive strip in a location where the faceplate  200  of an AMC carrier physically mates with the chassis. For a standards-based AMC carrier, this position is below the faceplate  200  and in front of a carrier cover connected to the bottom edge of the faceplate  200 . In certain embodiments, the channel  214 , or a similar channel in the same or a different location, may be positioned to support the adhesive strip in a location where the faceplate  200  physically contacts another faceplate in a carrier. 
         [0038]    The cross-sectional shape may also or instead include a tapered edge  220  on a top side  222  of the faceplate  200 . In general, the tapered edge  220  extends rearward from and substantially perpendicular to the rear surface  204 , and facilitates insertion of the faceplate  200  (and an assembled carrier including the faceplate  200 ) into a chassis. The tapered edge  220  may be angled so that the edge does not present any substantial surfaces perpendicular to a direction of insertion of the carrier, thus generally serving to facilitate insertion of an AMC carrier or the like into a chassis by easing the carrier into position, and preventing any perimeter surface of the faceplate from catching on any substantially parallel surface on an edge of the chassis opening (or an adjacent faceplate within the chassis). 
         [0039]    The cross-sectional shape may also or instead include a tapered edge  224  on a bottom side  226  of the faceplate  200 . In general, the tapered edge  224  extends rearward from and substantially perpendicular to the rear surface  204 , and facilitates insertion of the faceplate  200  (and an assembled carrier including the faceplate  200 ) into a chassis. The tapered edge  224  may be angled so that the edge does not present any substantial surfaces perpendicular to a direction of insertion of the carrier, thus generally serving to facilitate insertion of an AMC carrier or the like into a chassis by easing the carrier into position, and preventing any perimeter surface of the faceplate from catching on any substantially parallel surface on an edge of the chassis opening or an adjacent faceplate within the chassis. The tapered edge  224  may also or instead be shaped to facilitate attachment to a plurality of offset fingers extending from the bottom carrier cover as generally described above. It will be understood that while the tapered edges  220 ,  224  may be conveniently included within the cross-sectional shape of an extruded faceplate  200 , these features may also, or instead, be readily machined into the faceplate  200  according to cost, convenience, or any other factors that might be considered in fabricating faceplates  200  as generally described herein. 
         [0040]    The cross-sectional shape may also or instead include a card support  228  extending rearward from and substantially perpendicular to the rear surface  204  between the top side  222  and the bottom side  226  of the faceplate  200 . The card support  228  may have a number of notches and/or other machined features to physically align and support card guides such as the card guides  108  described above within a carrier. The card support  228  is discussed in greater detail below. 
         [0041]    Having described a number of extruded, cross-sectional features that generally support use of the faceplate with card carriers and improve on the features of a sheet metal faceplate, a number of machined features are now described in greater detail. These machined features are in general adapted for assembly of the faceplate into a substantially standards-compliant AMC carrier or the like. 
         [0042]      FIG. 3  is a front view of an extruded faceplate. The faceplate  300  has a length (from side to side horizontally in  FIG. 3 ) sized for use as a faceplate in an AMC carrier. In a typical embodiment, a four card AMC carrier would use a 350 millimeter wide faceplate, or an extrusion 350 millimeters long. However it will be understood that shorter or longer faceplates may suitably be employed for various configurations and applications. As described above, a top edge  302  and a bottom edge  304  contain a raised edge to secure an adhesive overlay or the like along a front surface of the faceplate  300 , it being understood that terms such as “top” and “bottom” are relative, and do not by themselves require any particular orientation of a card carrier or faceplate within a chassis or elsewhere. A number of machined features of the faceplate  300  are now described in greater detail. A wide range of machining, cutting, shaping, stamping, and hole cutting techniques are known in the art and may be suitably adapted to creating the machined features described herein. 
         [0043]    An opening  306  may be machined into the faceplate  300  to receive individual cards or modules in a carrier constructed from the faceplate  300 . For AMC carriers, the size and shape of this opening is largely defined by industry standards, as are many of the other features discussed below. The opening  306  may include a beveled edge  307  oriented to guide insertion of AMC modules into the opening  306  through the front surface of the faceplate  300 . 
         [0044]    One or more openings  308  may be provided to receive ejectors, such as any of the ejectors described above. Each opening  308  may extend through the faceplate  300  from a front side to a rear side of the faceplate  300  (as shown in  FIG. 2  above) and may be shaped and sized to receive an ejector such that a mechanically operative portion of the ejector can extend through the faceplate  300  and cooperate with a chassis to releasably secure a carrier in the chassis. For hot-swappable components, the ejector may also disconnect or otherwise control power when releasing a carrier from the chassis, with a corresponding LED or the like indicating when the carrier is coupled to power within the chassis. Numerous suitable ejectors are commercially available for use with ATCA-compliant carriers and the like. 
         [0045]    One or more through-holes  310  shaped and sized for light emitting diodes may be provided. The through-holes  310  may extend from the planar surface of the channel (front side) of the faceplate  300  to the rear side of the faceplate  300 . In general, the position of these through-holes  310  may be specified by an industry standard or custom or proprietary specification, and transparent or translucent regions may be provided in complementary positions in an adhesive overlay so that LEDs positioned in the through-holes  310  are visible when illuminated. 
         [0046]    One or more other through-holes  312  may also be provided that extend from a front side of the faceplate  300  to a rear side of the faceplate  300  for other components such as buttons, switches, dials and any other controls or human user interface components. In generally, each such through-hole  312  is shaped and sized for its intended component. Other through-holes  314  may be similarly provided for mechanical components such as captive screws, locating pins, carrier handles, and so forth. 
         [0047]      FIG. 4  is a rear view of an extruded faceplate. The faceplate  400  may be any of the faceplates described above. When viewed from this perspective, a number of extruded features are visible. This includes for example a bottom edge  402 , a card support  404 , and a top edge  406 . 
         [0048]    The bottom edge  402  generally extends continuously along most of a bottom of the faceplate  400 , and rearward from the interior of the faceplate  400 . Although not visible from this perspective, the bottom edge  402  may include a number of extruded features described above such as a channel for an adhesive EMI gasket and a tapered edge for easing the faceplate and an associated card carrier into a chassis. 
         [0049]    The card support  404  may extend rearward from and substantially perpendicular to the rear surface of the faceplate  400  as described above. The card support  404  is shown and described in greater detail below, but generally includes a number of notches machined into the surface thereof to support card guides in predetermined positions within a carrier. 
         [0050]    The top edge  406  may extend rearward from and substantially perpendicular to the rear surface of the faceplate  400 . In an embodiment, this extruded feature is mostly machined away when a card opening is formed in the faceplate. However, two regions of the top edge  406  may be retained as attachment legs for securing the faceplate  400  to a card guide strut, carrier cover, or the like. 
         [0051]      FIG. 5  is a top view of an extruded faceplate. The faceplate  500  may include any of the faceplates described above. From this top perspective, a number of features machined into extruded features of the faceplate  500  are visible, such as attachment legs  502  and a card support  504 . 
         [0052]    The attachment legs  502  may include one or more through-holes, and any other mechanical features suitable for attaching to, e.g., a card guide strut in a position that supports a carrier cover such as the top carrier cover described above. Although not visible from this perspective, it will be understood that the attachment legs  502  may include a tapered edge as generally described above for easing the faceplate  500  and an associated carrier into a chassis or the like. 
         [0053]    The card support  504  may extend rearward and substantially perpendicular to a rear surface of the faceplate  500 . While a perpendicular orientation may improve overall strength of the faceplate  500  and the card support  504 , it will be appreciated that this orientation is not required by the extrusion process, and is not required for use in supporting card guides. Thus it will be understood that this orientation is illustrative only and, as with other such statements of orientation or geometry herein, provided by way of example and not of limitation. The card support  504  generally serves to physically position and stabilize a number of card guides within a carrier. For this purpose, a number of notches  506  may be formed by machining or the like in a rear edge of the card support. Each notch  506  may include two opposing lateral supports  508 ,  510  for a card guide that is positioned behind the faceplate  500 . Each pair of lateral supports  508 ,  510  may serve to position and stabilize a card guide within a carrier constructed using the faceplate  500 . 
         [0054]      FIG. 6  is a bottom view of an extruded faceplate. The faceplate  600  may be, for example, any of the faceplates described above. From this perspective a bottom edge  602  of the faceplate  600  is visible. As described above, the bottom edge  602  generally extends continuously along most of a bottom of the faceplate  600 , and rearward from the rear or interior surface of the faceplate  600 . The bottom edge  602  may be tapered as described above, and may include a channel with raised edges  604  for an adhesive EMI gasket (not shown). 
         [0055]    According to the foregoing, there is described an extruded aluminum faceplate that substantially conforms to the sheet-metal oriented AdvancedTCA specification, while providing numerous advantages impossible or impractical in a sheet metal fabrication process. It will be understood that some aspects of the AdvancedTCA specification are mandatory, while others are encouraged or optional. In certain instances, aspects of a faceplate and carrier may deviate somewhat from the requirements of the AdvancedTCA specification without departing from the scope of the invention. While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is not to be limited by the foregoing examples, but is to be understood in the broadest sense allowable by law.