Abstract:
For use with a plate having a via located therethrough an electrical connector configured to transfer an electrical signal from one major surface of a plate to the other major surface, a method of manufacturing the electrical connector and a board mounted power supply utilizing the same. In one embodiment, the electrical connector comprises a dielectric layer coating a peripheral wall of the via and extending therefrom to coat portions of the opposing major surfaces of the plate adjacent the via. The electrical connector further comprises a conductive contact layer that covers a portion of the dielectric layer and extends to portions of the opposing major surfaces to form opposing contacts thereon.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention is directed, in general, to an interconnect for an active cooling system and, more specifically, to a device for providing an electrical interconnection through a plate between an electronic device and another associated device. 
     BACKGROUND OF THE INVENTION 
     Designers of electronic circuits must incorporate into their designs methods to control heat generated by electronic components in the circuit. Unless controlled, the heat build-up will cause component and circuit failure. Temperature control, therefore, is vital to circuit reliability. The preferred method to controlling temperature is to dissipate the excess heat into the ambient air surrounding the electronic circuit before temperatures rise to a level where damage can occur. 
     The traditional method to contain temperature build-up is to associate heat generating components with heat dissipation devices, such as heat sinks. The heat dissipation device absorbs heat from the component and provides for a more efficient transfer of excess heat into the surrounding ambient air. In most cases, the heat generating component will be mounted directly to the heat dissipation device to more efficiently remove the excess heat. 
     Although traditional heat sinking methods can be used successfully in most cases, the problems associated with temperature control have become more pronounced as electronic circuits have become more complex. Such circuit complexity often results in a circuit that requires a larger number of components, which frequently are more powerful and can generate even more heat. The problem is further complicated by the fact that lower profile and more compact electronic systems have become the preferred choice of customers. This means that space must be found in such low profile, compact systems for both the electronic components that make up the circuit as well as the heat dissipation devices that such components require in order to prevent heat related damage. In short, as the power density of circuits has increased, the use of classic finned heat sinks may no longer adequately address the corresponding heat dissipation requirements. 
     Some of the foregoing problems have been resolved by using active, rather than passive, systems to control temperature build up. For example, certain board mounted electronic components that generate large amounts of heat can have an active cooling device, such as a small fan, dedicated solely to the device. In those situations where a fan is used as the active device, the fan is typically mounted directly on the component and improves cooling by moving more ambient air over the component. Using a fan in this manner will provide more efficient cooling in less space than a classic finned heat sink. 
     Notwithstanding the benefits of having an active cooling device associated directly with a heat generating component, active cooling devices have certain shortcomings. One shortcoming is that such a device requires its own power source in order to operate. Prior art methods of providing this power usually involved the provision of a separate wiring path for the active device. Such a path may be provided by using separate connector pins on the substrate that are directly connected to the active device. This solution to the power problem raises additional problems, such as the added manufacturing expense of connecting the active device to an electrical power source during the assembly process. Other detrimental factors may arise when the active device must be removed for replacement or maintenance. Usually the active device must be manually disconnected and, when reinstalled, manually reconnected. This increases maintenance time and the potential for error. 
     Accordingly, what is needed in the art is a device that can provide electrical power to an active cooling device mounted on an electronic device that does not require a separately wired circuit. 
     SUMMARY OF THE INVENTION 
     To address the above-discussed deficiencies of the prior art, the present invention provides an electrical connector for use with a plate having a via located therethrough that is configured to transfer an electrical signal from one major surface of the plate to the other major surface of the plate. In one embodiment, the electrical connector is comprised of a dielectric layer coating a peripheral wall of the via and extending therefrom to coat portions of the opposing major surfaces of the plate adjacent the via. The electrical connector is further comprised of a conductive contact layer that covers a portion of the dielectric layer and extends to portions of the opposing major surfaces to form opposing contacts thereon. 
     The present invention, in broad scope, introduces an electrical connector that can be used to receive an electrical signal from an electronic device coupled to one side of a plate and transfer that electrical signal to another electronic device coupled to the other side of the plate. For example, the present invention can be used to electrically interconnect a board mounted power device and an active cooling device where the baseplate of the active cooling device is mounted on top of the power device. The electrical interconnect can be used for a number of purposes, such as furnishing operating power to the active cooling device or providing a feedback signal from the cooling device to the board mounted power device. 
     One embodiment of the invention provides for the electrical connector to have a copper layer as the conductive contact layer covering the dielectric layer. Of course, any material used as a conductive layer covering the dielectric layer will be within the scope of the present invention. 
     A particularly useful embodiment of the invention provides for the electrical connector to be located proximate a plurality of other electrical connectors that extend through other vias in the plate. This is particularly advantageous where certain connectors are used to transfer power, perhaps of different voltages, through the plate while other connectors are used to furnish other information, such as temperature or air velocity. 
     In one embodiment of the invention, the electrical connector is formed through a via of a base plate for a board mounted power supply. In another aspect of this embodiment, the board mounted power supply has an output that is electrically connected to the electrical connector. 
     In still another embodiment, the invention provides for an active cooling device that is couplable to the plate. An aspect of this embodiment provides for the active cooling device to further include a spring contact that provides electrical connectivity with the electrical connector. 
     The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
     FIG. 1A illustrates an isometric view of an embodiment of a board mounted power supply constructed in accordance with the principles of the present invention; 
     FIG. 1B illustrates another isometric view of the board mounted power supply of FIG. 1A; 
     FIG. 2 illustrates a planar side view of the board mounted power supply of FIG.  1 A and an unmounted active cooling device; and 
     FIG. 3 illustrates a cross-sectional view of an embodiment of an electrical connector constructed in accordance with the principles of the present invention. 
    
    
     DETAILED DESCRIPTION 
     Referring initially to FIGS. 1A and 1B, illustrated are isometric views of an embodiment of a board mounted power supply  100  constructed in accordance with the principles of the present invention. More specifically, FIG. 1A illustrates the board mounted power supply  100  with a top mounted integrated liquid cooling device  150  thereon. FIG. 1B illustrates another isometric view of the board mounted power supply  100  of FIG.  1 A. The board mounted power supply  100  has the integrated liquid cooling device  150  separated to reveal a top view of the board mounted power supply  100 . 
     With continuing reference to FIGS. 1A and 1B, the illustrated board mounted power supply  100  has a chassis  110  with power circuitry (not visible) located in the chassis  110 . The power circuitry, including the rectifiers, switches, transformer or combination of such devices contained in the chassis  110  will be familiar to those skilled in the pertinent art. The board mounted power module  100  has a base plate  120  located thereon that substantially covers the chassis  110 . The plate  120  has electrical connectors  130  associated with it, each of which is constructed in a via  135  through the plate  120 , as hereinafter described. The power supply circuitry in the chassis  110  has an output to which at least one of the electrical connectors  130  is coupled. 
     The present invention is particularly advantageous when used in combination with the illustrated integrated liquid cooling device  150 . The integrated liquid cooling device  150  is described in detail in U.S. patent application Ser. No. LUCT-120016, entitled INTEGRATED ACTIVE LIQUID COOLING DEVICE FOR BOARD MOUNTED ELECTRONIC COMPONENTS, to Chen, Shiaw-Jong, et. al., commonly assigned with the invention and incorporated herein by reference. 
     Located on the integrated liquid cooling device  150  are contacts  160  (not visible) that correspond to the electrical connectors  130  on the plate  120 . When the integrated liquid cooling device  150  is mounted on the board mounted power supply  100 , electrical connectivity will be established between the cooling device  150  and the electrical connectors  130 . In order to assure electrical connectivity, in one embodiment of the invention, the contacts  160  on the cooling device  150  may be spring contacts. 
     The advantages of the present invention are clearly illustrated in FIGS. 1A and 1B. The integrated liquid cooling device  150  is commonly known in the art as an active cooling device. That is, instead of relying on a heat sink to passively conduct heat from a heat generating component of the board mounted power supply  100  to a surface where it is transferred to the surrounding ambient air, the cooling device actively gathers the heat from the component and transfers it to the surrounding ambient air. 
     In the present case, the integrated liquid cooling device  150  moves a coolant through a closed-circuit circulation pipe  170  to gather heat from the board mounted power supply  100  and transfer it to the surrounding ambient air. In order to pump the coolant through the closed-circuit circulation pipe  170 , the cooling device  150  has a pump  180  that is coupled to the pipe  170 . When the pump  180  moves the coolant to a position where it can readily be dissipated into the surrounding ambient air, a fan  190  moves air across the pipe  170  and accelerates the transfer of heat. 
     It is readily apparent that both the pump  180  and the fan  190  on the integrated liquid cooling device  150  require power in order to operate. Prior art solutions to providing power to the fan  190  and pump  180  would require power cords from the fan  190  and pump  180  to be connected to a power source. The present invention, however, advantageously provides electrical power to run the fan  190  and pump  180  directly from the power supply circuitry in the chassis  110 . In the illustrated embodiment, the chassis  110  has an output to the electrical connector  130  on the chassis  110  side of the base plate  120 . When the integrated liquid cooling device  150  is mounted on the board mounted power supply  100 , the contacts  160  on the cooling device  150  complete the circuit through the connectors  130  formed through the vias  135  in the base plate  120  to provide electrical power to the pump  180  and fan  190 . 
     Although the present invention requires only one electrical connector  130 , in the illustrated embodiment, a plurality of vias  135  and connectors  130  are provided. The plurality of connectors  130  can be used for a variety of purposes, including powering more than one device or providing feedback of temperature and other useful information to the board mounted power supply  100 . 
     Turning now to FIG. 2, illustrated is a planar side view of the board mounted power supply  100  of FIG.  1 A and an unmounted active cooling device  200 . This embodiment illustrates the provision of electrical power to an active cooling device  200  that is only using a fan  210 . The power module  100  has a base plate  120  with electrical connectors  130  in vias  135  through the base plate  120 . An output of the board mounted power supply  100  is electrically connected to the electrical connectors  130 . This embodiment of the active cooling device  200  has spring contacts  220 . When the active cooling device  200  is mounted on the board mounted power supply  100 , the contacts  220  will be electrically connected to the electrical connectors  130  and provide electrical power to run the fan  210 . Other contacts  220  may be connected to other electrical connectors  130  to provide power to other devices or to provide feedback information. 
     Turning now to FIG. 3, illustrated is a cross-sectional view of an embodiment of an electrical connector  130  constructed in accordance with the principles of the present invention. The electrical connector  130  is employable with a plate  120  having a via  135  located therethrough. The via  135  has a dielectric layer  310  coating a peripheral wall of the via  135  and extending therefrom to coat a portion of an opposing major surface  315  on each side of the plate  120  adjacent to the via  135 . In the illustrated embodiment, the dielectric layer  310  may be 1 to 8 mils thick. Of course, the thickness of the dielectric layer  310  may be modified as a particular application may dictate. 
     Covering a portion of the dielectric layer  310  is a conductive contact layer  320  that covers a portion of the dielectric layer  310  and extends to portions of the opposing major surfaces  315  to form an opposing contact  330  on each of the opposing major surfaces  315 . Those skilled in the pertinent art will readily understand and recognize that an electrical power source connected to the contact  330  on one side of the plate  120  will be electrically connected to the contact  330  on the opposing side of the plate  120 . In the illustrated embodiment, the conductive contact layer  320  is a copper layer that is 2 to 6 ounces thick. Of course, the thickness of the copper layer may be modified as a particular application may dictate. Although the illustrated embodiment of the invention provides for the conductive contact layer  320  to be comprised of copper, other conductive materials, such as platinum, gold, silver, etc., can also be used as the conductive contact layer  320 . 
     Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.