Patent Application
20050068754
Computers are customarily provided with sheet metal cage structures that contains a back plane. A back plane is a circuit board (e.g., mother card) or framework that supports other circuit boards, devices, and the interconnections among devices, and provides power and data signals to supported devices. The mother card is the main circuit card in the computer which connects to the back plane of the logic board. The computer cage structure is adapted to receive and removably support at least one and preferably a plurality of options or daughter cards (blades or nodes) which when operatively installed in their associated cage structure, upgrade the operating capabilities of the computer. For example, it is known to place an assembly, including a backplane and various circuit boards, such as a processor card, an input-output card and a so-called memory riser card, within an open cage. This forms a so-called central electronic complex (CEC) of a computer system. The cage is subsequently fixed within a computer housing.
A standard containing enclosure or cage protects the individual daughter cards and facilitates the easy insertion and removal of the daughter cards from a mother card (mother board) or back plane slot. These daughter cards may be installed in the computer during the original manufacture of the computer and or subsequently installed by the computer purchaser. The cage serves to position the circuit boards within the computer housing, and acts as an EMC (electromagnetic compatible) shield. An EMC shield allows operation in an electromagnetic environment at an optimal level of efficiency, and allows static charges to be drained to a frame ground. Moreover, the cage helps to protect the components contained therein from environmental damage, for example, vibrations, which could cause the components to fail.
Additionally, the cage is typically fixed within a so-called system chassis, which is a frame that provides further support for the cage, and which is removably stacked upon other system chassises within a system rack. The chassis may contain other components and sub-systems, such as power supplies and cooling fans, for example, which are connected to the components within the cage using cables, for instance.
A daughter card may include a relatively small rectangular printed circuit having a connecter along one side edge, a 24″×24″ node weighing over a hundred pounds, or a server, for example. The mother card or system back plane slot has a socket connector. The daughter card connector plugs into a corresponding socket connector of the mother card to operatively couple the daughter card to the mother card or system back plane slot. In order to allow the circuit boards or daughter cards to be connected to the backplane, it is also typical to position the backplane at a rear of the cage, and in a vertical position. This allows the circuit boards or daughter cards to be plugged into the card slots of the backplane through the open front, for example, of the cage.
Data processing systems in general and server-class systems in particular are frequently implemented with a server chassis or cabinet having a plurality of racks. Each cabinet rack can hold a rack mounted device (e.g., a daughter card, also referred to hereinas a node, blade or server blade) on which one or more general purpose processors and/or memory devices are attached. The racks are vertically spaced within the cabinet according to an industry standard displacement (the “U”). Cabinets and racks are characterized in terms of this dimension such that, for example, a 42U cabinet is capable of receiving 42 1U rack-mounted devices, 21 2U devices, and so forth. Dense server designs are also becoming available, which allow a server chassis to be inserted into a cabinet rack, thus allowing greater densities than one server per 1U. To achieve these greater densities, the server chassis may provide shared components, such as power supplies, fans, or media access devices which can be shared among all of the blades in the server blade chassis.
However, there is a significant problem of making multiple simultaneous connections onto a single node or blade on insertion. The problem arises from divergent needs of power and signal interconnection with the node or daughter card. The power interconnect often requires high currents and thus large, rugged conductive interfaces. These interfaces are often bolted bus bars or post in holes type interconnects which cannot support high precision assemble. The signal interconnect on the other hand requires high density pin fields that are relatively fragile and require very precise plug and guidance systems. Another problem is the need for daughter card edge real estate on high density daughter cards. Often the need for I/O and power interconnects compete for the same, limited card edges for interface connectors.
In addition, when the daughter card is removed from the cage for service, typically the connections between the daughter card and the other cage components within the cage must be manually disconnected and reconnected. This is a relatively time consuming process. Thus, there is a need for an arrangement that will allow for the removal of the daughter card for servicing, for example, which does not require manually connecting and disconnecting various electrical connectors to provide signal and power interconnection therebetween while providing an easy and reliable means to align the daughter card to make such signal and power interconnections within the cage.
A multiple card enclosure including a mother card cage having a mother card enclosed therein and a daughter card removably positioned within the cage for connecting the daughter card with the mother card is disclosed. The daughter card includes a power tab extending from a first edge defining the card and a signal connector extending from a second edge perpendicular to the first edge. The signal connector is configured to connect to the mother card for signal interconnection therebetween. A guide means is configured to guide the daughter card into the mother card cage and in signal interconnection with the mother card and is configured to provide power into and out of the daughter card via connection with the power tab.
In an exemplary embodiment, a multiple card enclosure includes a mother card cage having a mother card enclosed therein and a daughter card removably positioned within the cage for connecting the daughter card with the mother card. The daughter card includes a power tab extending from a first edge defining the card and a signal connector extending from a second edge perpendicular to the first edge. The signal connector is configured to connect to the mother card for signal interconnection therebetween. At least one guide rail connects the daughter card within the enclosure as the daughter card is slidably disposed on the rail and guides the daughter card into the cage using the rail. The power tab extending from the daughter card is slidably received by the guide rail and allows the daughter card to properly register with the mother card. The guide rail includes a power receptacle disposed within the rail and is configured to operably provide power interconnection between the tab and a power supply when the card is plugged into the cage. The guide rail aligns the tab relative to the receptacle for power interconnection therebetween and guides the signal connector to the mother card for signal interconnection therebetween by guiding the tab within the rail when the card is slid into the cage.
Referring now to the exemplary drawings wherein like elements are numbered alike in the several FIGURES:
The invention will now be described in more detail by way of example with reference to the embodiments shown in the accompanying figures. It should be kept in mind that the following described embodiments are only presented by way of example and should not be construed as limiting the inventive concept to any particular physical configuration.
Further, if used and unless otherwise stated, the terms “upper”, “lower”, “front”, “back”, “over”, “under”, and similar such terms are not to be construed as limiting the invention to a particular orientation. Instead, these terms are used only on a relative basis.
As shown, the cage 12 has a box shape with a generally rectangular cross-sectional profile, and is formed of two cavities on one side of midplane 14, generally shown at 20 and 21, while three cavities are defined on an opposite side of midplane 14 with generally horizontal, spaced apart walls 22, 23, and 24 joined together by generally upright, midwall 26 extending from wall 24. Wall 22 defines a bottom floor defining cage 12. Wall 23 extends to midwall 26 defining a bus bar access area discussed more fully herein. Wall 24 defines a floor defining a cavity in which a plurality of daughter cards 16 may be disposed and interconnected with midplane 14. The walls 22, 23, and 24 define spaces within the cage 12, which contain air, power, and docking systems for a plurality of daughter cards 16 installed in the cage.
The cage 12 is dimensioned to accommodate the midplane 14 and a plurality of daughter cards 16, (four shown) as will be subsequently described. Moreover, the cage 12 is preferably comprised of sheet metal, which can be easily manipulated to form the walls 22, 23, 24, 26, although other materials, such as plastic, may also be used. However, it is preferable that the material used to form the cage 12 be conductive, so that the cage can serve as an EMC shield.
As best shown with reference to both
The stiffener panel 30 is connectable to the cage 12, for example, by fastening the stiffener panel to a flange 32 disposed on a lower bottom edge of walls 24. For example, the stiffener panel 30 can be screwed, bolted or welded to the flange 32. Other means for connecting the stiffener panel 30 to the cage 12 are within the scope of the present invention. When connected, the backplane 14 partially divides the cage 12 in two, and serves as a partial divider of the cage, with the printed circuit board 28 perpendicular thereto.
Preferably, an end distal from a backplane stiffener panel 33 has a tailstock 34 disposed thereon. As is known, a tailstock is a fixture or bezel that provides physical support for the associated electrical device (for example, the I/O card 18), and which provides for a limited amount of electromagnetic radiation shielding and is configured to be reworkable.
The tailstock 34 is provided with a plurality of apertures 36, which form ports that allow various external peripherals to be connected to the backplane 14. For example, in the exemplary illustrated embodiment, the tailstock 34 is provided with eight such ports (
The tailstock 34 is preferably tailored to allow it to be fastened to stiffener 30 (shown in
Each daughter card 16 is generally planar, rectangular structures, with lengths that are substantially the same as their heights, as illustrated, but not limited thereto. As previously mentioned, the cage 12 can then be advantageously tailored in the same manner (with a length that is about the same as its height), so as to receive the respective cards 16 therein with a minimum amount of wasted space.
When installed in the cage 12, the cards 16 are essentially parallel to each other, and essentially perpendicular to the major surfaces of the backplane 14. However, other orientations may be possible, within the scope of the present invention.
The daughter card 16 is preferably removably coupled to the backplane 14 by inserting a known corresponding plug connector, such as a dual row of full edge length very high density metricinterconnector (VHDM) 39 (not shown in detail
As illustrated in
Further, and as illustrated best in
Although the present embodiment has been described in connection with a daughter card 16 having a pair of MCMs 17, it is contemplated that the same inventive scheme can be utilized with other types of circuit boards. Moreover, it is also contemplated that the respective cards will be specifically tailored for use with the cage 12. For example, in the above-described exemplary embodiment, the plug connector of the daughter card is disposed symmetrically, that is, along a full length of the edge of the card.
As will be appreciated, since the cards 16 may be modified by the user, it is advantageous if the cards be easily accessible. As previously discussed, each card is accessed through the open front of the cage 12. Conventionally, the cages are each positioned within a respective chassis, each having an open top, with the respective chassises and cages being stacked upon each other. As such, in order to access a cage within a lower positioned chassis, it had conventionally been necessary to remove the associated chassis from a rack.
As best shown in
Preferably with reference to
In the illustrated exemplary embodiment, and as best shown in
Preferably, in order to facilitate the electrical connections between the components of the cage 12 and those disposed on card 16, the cage is provided with an autodocking feature that automatically couples the backplane 14, for example, with the dual row of VHDM 39 within the cage 12. In the illustrated exemplary embodiment, the autodocking feature includes at least one power tab 76 extending from a middle portion of card 16 (shown in
When the card 16 is fully received within the cage 12, the projecting receptacles 80 engage with the respective tabs 76 providing power interconnection therebetween, thereby coupling the backplane 14 with the other components disposed on card 16 and in signal interconnection therebetween on a separate card edge independent of edges substantially perpendicular thereto used for power interconnection. Likewise, when the card 16 is slid out of the cage 12, the projecting receptacles 80 automatically disengage with the respective tabs 76, thereby electrically uncoupling the backplane 14 from the other components disposed on card 16. This arrangement advantageously eliminates the need to manually disconnect various electrical connections between the cage and the chassis, when the cage is removed. Of course, it is contemplated that the backplane can be coupled to the other components in the chassis using other arrangements, without departing from the spirit of the invention.
Furthermore, the power guide rails 58 are configured and aligned to ensure that each card 16 is properly positioned and automatically aligned relative to signal interconnection with backplane 14 during the autodocking procedure. This arrangement allows for float and staging (such as just before end-of-travel-kick-up) for signal connector alignment at the midplane edge of card 16. Thus, the respective electrical connections (e.g., power and signal) can be coupled together automatically, reliably, and quickly.
As will be appreciated, this configuration advantageously uses gravity to help retain the cards 16 in position. That is, the weight of the respective cards 16 urges the cards in a direction toward the power guide rails 58. Thus, each card 16 is less likely to inadvertently disengage with a respective lower receptacle 80 providing power to bus bar 78 via power tab 76 avoiding power interruptions thereby. It will be recognized that such connections can be for multiple voltages and at the top edge, bottom edge, or both edges of card 16. In an exemplary embodiment, tabs 76 are preferably configured of staged width such that tabs 76 are narrower as they approach a midplane edge of card 16. In this manner, tabs 76 are easily wedged into power connection with a corresponding receptacle 80 when card 16 is slid toward backplane 14.
Although each receptacle 80 has been described as being serially aligned within each rail 58, it is also contemplated that receptacles 80 may be aligned in parallel or be concentric with respect to one another and rail 58. In addition, it is further contemplated that each receptacle may be a staged receptacle such that one side defining each power fork is at a first voltage level, while an opposite side is at a second voltage different form the first voltage. In this manner, a receptacle may provide staged power (e.g., ground and +V) to a corresponding side defining a power tab 76, wherein each side is insulated from the opposing side at a different potential. For instance, power tab 76 may be a laminated power tab.
Receptacle 80 receives power from supply 68 via a bus bar 82 connection therebetween, however, it is contemplated that a conductive wire may be employed as well. Bus bar 82 preferably extends from power supply 68 and is disposed on wall 23 before extending in electrical communication with receptacle 80 extending through guide rail 58.
In an exemplary embodiment with reference to
More specifically with reference to
Still referring to
The above described embodiments get power into and out of the daughter card, while providing for a pluggable, concurrently maintainable daughter card packaged as an extremely dense, high power (e.g., about 2000 Amperes of logic power with a low voltage drop and low impedance), air cooled, heavy node. The above configuration having two full length VHDMs 39 further provides 3120 high speed signal I/O to midplane 14 while maintaining an 18U cage. The power guide rail system disclosed herein does not interfere with midplane connector alignment, float range, and vertical kick proximate an end of node guidance to allow nominal centering on midplane guide posts.
The current embodiments shown with respect to the figures demonstrate cage 12 with one daughter card 16 disposed therein and guide rails for three more. However, in other embodiments, more or less than four daughter cards 16 are contemplated, and not limited thereto. The figures show a configuration that allows the daughter card 16 to be mounted inside cage 12, side-by-side relative to one another. The daughter cards 16 are co-planar within the CEC enclosure. Multiple technologies associated with the multiple daughter cards 16 can be interchanged with a single mother card in a logic board. The multiple card enclosure provides for serviceability and adaptability of the system while getting power into and out of the daughter card via a guide rail without affecting the associated real estate and interconnection between the midplane edge of card 16 and the midplane 14.
As computer architectures evolve into high density symmetric multi-processing (SMP) configurations built on large nodes or blades (e.g., larger daughter cards), the plugging and interconnect of these nodes/blades becomes significantly more difficult. The above described configuration discloses an integrated guide rail system configured to both guide and retain the node or blade as well as provide a high current electrical interconnect required to provide power to the node or blade. The integrated guide rail system occupies card edge real estate different from that required for the high density signal interconnects allowing for premium card edge real estate to be used for SMP signal interconnect. Further, by disposing the power interconnects proximate a middle portion of the card, the guide rail system provides enough float for the more sensitive connection between the high density signal interconnects and the system backplane. The above disclosed configuration also eliminates creation of localized high currents on the card common with traditional power interconnect system and methods.
Moreover, the above described configuration allows for multiple voltages to be distributed along a length guiding the system guide rail, however, it is contemplated that the power interconnects may be oriented in parallel or concentric instead of being serially oriented.
Lastly, the above described configuration combines a node/blade guide with one or more power interconnects thereby reducing load coupling from multiple interconnects. In addition, configuring the power tabs as staged power interconnects enhance this endeavor.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
