Patent Abstract:
A system and method for interconnecting circuit boards is disclosed. The apparatus comprises a first circuit board, having an aperture comprising a plurality of aperture conductive surfaces disposed on an inner surface of the aperture, at least one of the conductive surfaces communicatively coupled to at least one of a plurality of first circuit board traces; a second circuit board, having a plurality of second circuit board traces; and a connector disposed at least partially through the aperture and between the first circuit board and the second circuit board, the connector having a plurality of conductive signal conductors, each having a first portion disposed at the periphery of the connector and adjacent to the aperture conductive surfaces and a second portion communicatively coupled with the second circuit board traces.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims benefit of the following U.S. Provisional Patent Applications, each of which is hereby incorporated by reference herein:  
         [0002]    Application Ser. No. 60/222,386, entitled “HIGH DENSITY CIRCULAR ‘PIN’ CONNECTOR FOR HIGH SPEED SIGNAL INTERCONNECT”, by David H. Hartke and Joseph T. DiBene II, filed Aug. 2, 2000;  
         [0003]    Application Ser. No. 60/222,407, entitled “VAPOR HEATSINK COMBINATION FOR HIGH EFFICIENCY THERMAL MANAGEMENT”, by David H. Hartke and Joseph T. DiBene II, filed Aug. 2, 2000;  
         [0004]    Application Ser. No. 60/232,971, entitled “INTEGRATED POWER DISTRIBUTION AND SEMICONDUCTOR PACKAGE,” by Joseph T. DiBene II and James J. Hjerpe, filed Sep. 14, 2000;  
         [0005]    Application Ser. No. 60/251,222, entitled “INTEGRATED POWER DELIVERY WITH FLEX CIRCUIT INTERCONNECTION FOR HIGH DENSITY POWER CIRCUITS FOR INTEGRATED CIRCUITS AND SYSTEMS,” by Joseph T. DiBene II and David H. Hartke, filed Dec. 4, 2000;  
         [0006]    Application Ser. No. 60/251,223, entitled “MICRO-I-PAK FOR POWER DELIVERY TO MICROELECTRONICS,” by Joseph T. DiBene II and Carl E. Hoge, filed Dec. 4, 2000;  
         [0007]    Application Ser. No. 60/251,184, entitled “MICROPROCESSOR INTEGRATED PACKAGING,” by Joseph T. DiBene II, filed Dec. 4, 2000;  
         [0008]    Application Ser. No. 60/266,941, entitled “MECHANICAL INTERCONNECTION TECHNOLOGIES USING FLEX CABLE INTERCONNECT FOR POWER DELIVERY IN ‘INCEP’ INTEGRATED ARCHITECTURE,” by Joseph T. DiBene II, David H. Hartke, and James M. Broder, filed Feb. 6, 2001;  
         [0009]    Application Ser. No. 60/277,369, entitled “THERMAL-MECHANICAL MEASUREMENT AND ANALYSIS OF ADVANCED THERMAL INTERFACE MATERIAL CONSTRUCTION,” by Joseph T. DiBene II, David H. Hartke and Farhad Raiszadeh, filed Mar. 19, 2001;  
         [0010]    Application Ser. No. 60/287,860, entitled “POWER TRANSMISSION DEVICE,” by Joseph T. DiBene II, David H. Hartke, Carl E. Hoge, and Edward J. Derian, filed May 1, 2001;  
         [0011]    Application Ser. No. 60/291,749, entitled “MICRO I-PAK ARCHITECTURE HAVING A FLEXIBLE CONNECTOR BETWEEN A VOLTAGE REGULATION MODULE AND SUBSTRATE,” by Joseph T. DiBene II, filed May 16, 2001;  
         [0012]    Application Ser. No. 60/291,772, entitled “I-PAK ARCHITECTURE POWERING MULTIPLE DEVICES,” by Joseph T. DiBene II, David H. Hartke, Carl E. Hoge, and Edward J. Derian, filed May 16, 2001;  
         [0013]    Application Ser. No. 60/292,125, entitled “VORTEX HEATSINK FOR LOW PRESSURE DROP HIGH PERFORMANCE THERMAL MANAGEMENT ELECTRONIC ASSEMBLY SOLUTIONS,” by Joseph T. DiBene II, Farhad Raiszadeh, filed May 18, 2001;  
         [0014]    Application Ser. No. 60/299,573, entitled “IMPROVED MICRO-I-PAK STACK-UP ARCHITECTURE,” by Joseph T. DiBene, Carl E. Hoge, and David H. Hartke, filed Jun. 19, 2001;  
         [0015]    Application Ser. No. 60/301,753, entitled “INTEGRATED POWER DELIVERY USING HIGH PERFORMANCE LINEAR REGULATORS ON PACKAGE WITH A MICROPROCESSOR,” by Joseph T. DiBene II, Carl E. Hoge, and David H. Hartke, filed Jun. 27, 2001;  
         [0016]    Application Ser. No. 60/304,929, entitled “BORREGO ARCHITECTURE,” by David H. Hartke and Joseph T. DiBene II, filed Jul. 11, 2001; and  
         [0017]    Application Ser. No. 60/304,930, entitled “MICRO-I-PAK,” by Joseph T. DiBene II, Carl E. Hoge, David H. Hartke, and Edward J. Derian, filed Jul. 11, 2001.  
         [0018]    This patent application is also a continuation-in-part of the following co-pending and commonly assigned patent applications, each of which applications are hereby incorporated by reference herein:  
         [0019]    application Ser. No. 09/353,428, entitled “INTER-CIRCUIT ENCAPSULATED PACKAGING,” by Joseph T. DiBene II and David H. Hartke, filed Jul. 15, 1999;  
         [0020]    application Ser. No. 09/432,878, entitled “INTER-CIRCUIT ENCAPSULATED PACKAGING FOR POWER DELIVERY,” by Joseph T. DiBene II and David H. Hartke, filed Nov. 2, 1999;  
         [0021]    application Ser. No. 09/727,016, entitled “EMI CONTAINMENT USING INTER-CIRCUIT ENCAPSULATED PACKAGING TECHNOLOGY” by Joseph T. DiBene II and David Hartke, filed Nov. 28, 2000;  
         [0022]    application Ser. No. 09/785,892, entitled “METHOD AND APPARATUS FOR PROVIDING POWER TO A MICROPROCESSOR WITH INTEGRATED THERMAL AND EMI MANAGEMENT,” by Joseph T. DiBene II, David H. Hartke, James J. Hjerpe Kaskade, and Carl E. Hoge, filed Feb. 16, 2001; and  
         [0023]    application Ser. No. 09/798,541, entitled “THERMAL/MECHANICAL SPRINGBEAM MECHANISM FOR HEAT TRANSFER FROM HEAT SOURCE TO HEAT DISSIPATING DEVICE,” by Joseph T. DiBene II, David H. Hartke, Wendell C. Johnson, and Edward J. Derian, filed Mar. 2, 2001;  
         [0024]    application Ser. No. 09/801,437, entitled “METHOD AND APPARATUS FOR DELIVERING POWER TO HIGH PERFORMANCE ELECTRONIC ASSEMBLIES” by Joseph T. DiBene II, David H. Hartke, Carl E. Hoge, James M. Broder, Edward J. Derian, Joseph S. Riel, and Jose B. San Andres, filed Mar. 8, 2001;  
         [0025]    application Ser. No. 09/802,329, entitled “METHOD AND APPARATUS FOR THERMAL AND MECHANICAL MANAGEMENT OF A POWER REGULATOR MODULE AND MICROPROCESSOR IN CONTACT WITH A THERMALLY CONDUCTING PLATE” by Joseph T. DiBene II and David H. Hartke, filed Mar. 8, 2001;  
         [0026]    application Ser. No. ______, entitled “HIGH PERFORMANCE THERMAL/MECHANICAL INTERFACE FOR FIXED-GAP REFERENCES FOR HIGH HEAT FLUX AND POWER SEMICONDUCTOR APPLICATIONS”, by Joseph T. DiBene, II, David H. Hartke, Wendell C. Johnson, Farhad Raiszadeh, Edward J. Darien and Jose B. San Andres, filed Jul. 20, 2001; and  
         [0027]    application Ser. No. ______, entitled “VAPOR CHAMBER WITH INTEGRATED PIN ARRAY”, by Joseph T. DiBene, II and Farhad Raiszadeh, filed on same date herewith. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0028]    1. Field of the Invention  
           [0029]    This present invention relates to systems and methods for interconnecting circuit traces and signals between circuit boards, and in particular to a signal interconnection system for transmitting very high-speed signals between devices on such circuit boards.  
           [0030]    2. Description of the Related Art  
           [0031]    In the past decade, processor and data transmission speeds have increased dramatically. As these speeds continue to increase, there is a corresponding need to provide signal interconnections between printed circuit boards that are compatible with the transmission of such high speed data. At the same time, there is a trend to increase the number of signals carried on printed circuit boards and to decrease the size of the circuit boards. Consequently, the density of signals and circuit traces that carry them is rising. Further, parasitic parameters such as impedance and cross-coupling between interconnection paths typically increase as signal speed and frequency increase.  
           [0032]    Thus, it is seen that there is a need for an interconnection system for communicatively coupling circuit traces and components carrying high-speed signals between printed circuit boards that provides high signal density while reducing noise and crosstalk at both the board level and connector level. There is also a need for an interconnection system that provides the foregoing advantages at a low manufacturing cost. The present invention satisfies that need.  
         SUMMARY OF THE INVENTION  
         [0033]    To address the requirements described above, the present invention discloses a system and method for interconnecting circuit boards. The apparatus comprises a first circuit board, having an aperture comprising a plurality of aperture conductive surfaces disposed on an inner surface of the aperture, at least one of the conductive surfaces communicatively coupled to at least one of a plurality of first circuit board traces; a second circuit board, having a plurality of second circuit board traces; and a connector disposed at least partially through the aperture in the first circuit board and between the first circuit board and the second circuit board, the connector having a plurality of conductive signal conductors, each having a first portion disposed at the periphery of the connector and adjacent to the aperture conductive surfaces and a second portion communicatively coupled with the second circuit board traces.  
           [0034]    The present invention enables very high speed signals to be transmitted between printed circuit boards (both perpendicular and parallel to each other) with low noise and in a small form factor. The construction is circular in fashion with the signal connections being on the periphery of the connector housing. One side of the signals go down into the PCB where the connector is permanently attached (soldered or press-fit as an example) into one of the two PCBs. The other side extends into a hole drilled into the PCB where multiple connections are provided on the sides of the PCB for signal connection. Because the routing to the connector is completely radial in fashion, this allows signals to funnel into a central point reducing unwanted crosstalk and noise between the signals. The signals on the ‘connector’ side PCB house spring contacts which interconnect into plated walls on the PCB while providing for radial distribution of the signals to and from devices on the PCB. The radius of the construction may be varied to increase or decrease signal interconnect quantity as needed as well as the pitch of the signal conductors. A shield may be added to the outside of the assembly for reference and noise mitigation. Multiple connectors may be joined in various arrangements for ease in manufacturing and assembly. Additionally, the construction may be designed for right angle applications. And finally, the construction may be used for cable connector arrangements where the conductors are connected to wires in a cable for connections between cables, PCBs, or other connector systems where the interconnect is the same. The interconnect is a circular construction in fashion and utilizes one of the PCBs as the actual connector.  
           [0035]    Signals from a device on PCB are transmitted through a PCB to the aforementioned connector. The conductors are arranged such that the signals traverse into the connector in a radial fashion. This lends itself to minimizing crosstalk and other PCB noise due to the radial fashion of the construction forcing signals to separate prior to entering the connector. The signals then traverse through the connector conductors to the upper PCB where they are distributed from the connector in a radial fashion. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0036]    Referring now to the drawings in which like reference numbers represent corresponding parts throughout:  
         [0037]    [0037]FIG. 1A is a diagram of one embodiment of a circuit board assembly  100 ;  
         [0038]    [0038]FIG. 1B is a diagram showing an assembled view of the structures disclosed in FIG. 1A;  
         [0039]    [0039]FIG. 2A is a diagram presenting a side view of additional detail regarding one embodiment of the connector;  
         [0040]    [0040]FIG. 2B is a diagram presenting a top view of one embodiment of the connector;  
         [0041]    [0041]FIG. 3A is a diagram illustrating a top view of one embodiment of the second circuit board, showing how signal traces can be routed to and from the connector;  
         [0042]    [0042]FIG. 3B is a diagram illustrating a top view of one embodiment of the first circuit board, showing how signal traces can be routed to and from the connector;  
         [0043]    [0043]FIG. 4 is a diagram illustrating another top view of the first circuit board and aperture;  
         [0044]    [0044]FIG. 5 is a diagram illustrating an “L” shaped connector;  
         [0045]    [0045]FIG. 6 is a diagram presenting an embodiment having a conductive shield; and  
         [0046]    [0046]FIGS. 7A and 7B are diagrams presenting an embodiment with spring contacts on both sides of the connector. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0047]    In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, several embodiments of the present invention. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.  
         [0048]    [0048]FIG. 1A is a diagram of one embodiment of a circuit board assembly  100 . The circuit board assembly  100  comprises a first circuit board  102  and a second circuit board  104 . A connector  106  is disposed between the first circuit board  102  and the second circuit board  104 . The connector  106  communicatively couples circuit traces  118 A and  118 B (alternatively collectively referred to hereinafter as circuit traces  118 ) in or on the first circuit board  102  and second circuit traces  120 A and  120 B (hereinafter alternatively collectively referred to as second circuit traces  120 ) in or on the second circuit board  104 .  
         [0049]    The first circuit board  102  includes an aperture  108 . The aperture  108  includes conducting surfaces  116 A and  116 B (hereinafter alternatively collectively referred to as conducting surfaces  116 ) communicatively coupled to the circuit traces  118 . Similarly, in the embodiment disclosed in FIG. 1A, the second circuit board  104  includes one or more second circuit board apertures  112  or through-holes which allow permanent mounting of the connector  106  to the second circuit board  104 . The second circuit board  104  also includes a through-hole  114  that permits insertion of a mechanical fastener to couple the connector  106  to the second circuit board  104  (and, if desired to the first circuit board  102 ). The second circuit board  104  also includes apertures  112 A and  112 B (hereinafter alternatively collectively referred to as apertures  112 ) such as through-holes. In one embodiment, the apertures  112  are plated with conductive material, and are communicatively coupled to circuit traces  120 A and  120 B in or on the second circuit board  104 .  
         [0050]    The connector  106  includes a substantially non-conducting housing  124  and a plurality of conductive signal conductors  126 A and  126 B (hereinafter alternatively referred to as signal conductors  126 ) disposed on a periphery of the housing  124 . In the illustrated embodiment, the signal conductors  126 A and  126 B include a first portion  128 A and  128 B, respectively and second portions  130 A and  130 B, respectively. The first portions  128 A and  128 B each include a spring structure which, when the connector  106  is placed within the aperture  108 , is urged against the conductive surfaces  116 A and  116 B, respectively on the inner surface of the aperture  108 , thus communicatively coupling the signal conductor second portions  130 A and  130 B with signal traces  118 A and  118 B. Further, when the connector  106  is communicatively coupled to the second circuit board (e.g. by communicatively coupling the signal conductor second portions  130 A and  130 B to plated apertures  112 A and  112 B, respectively), communicative coupling is established between circuit board traces  120 A and  118 A and between circuit board traces  120 B and  118 B.  
         [0051]    In one embodiment, the non-conductive housing  124  is a molded plastic material, and the signal conductors  126  are molded into the housing. The second portion  130  of the signal conductors  126  are securely held by the housing  124  for mounting to the second circuit board  104  and the first portion  128  of the signal conductors  126  are spring-loaded by the cap  132 . The cap can be a separate structure, or may be integrated with the housing  124 .  
         [0052]    In one embodiment, the connector  106  further comprises a cap  132 . The cap  132  can be inserted into the housing, thus urging the spring structure away from the housing  124  to facilitate contact with the conductive surfaces  116 A and  116 B of the first circuit board  102  when the connector  106  is inserted into the aperture  108 . The cap  132  may also include an aperture  122  disposed therethrough, to allow insertion of a screw or other fastener.  
         [0053]    [0053]FIG. 1B is a diagram showing an assembled view of the structures disclosed in FIG. 1A.  
         [0054]    [0054]FIG. 2A is a diagram presenting a side view of additional detail regarding one embodiment of the connector  106 .  
         [0055]    [0055]FIG. 2B is a diagram presenting a top view of one embodiment of the connector  106 . In this embodiment, the signal conductors  126  are radially and equidistantly disposed about the periphery of the connector  106 . FIG. 2B also shows that the cross section of the connector  106  (and the aperture  108 ) is circular. However, the connector  106  may have different cross-sectional shapes, including ovoid, elliptical, trapezoidal, rectangular, or square. Further, the signal conductors  126  can be disposed in any pattern as desired for the particular signal carried on the signal conductor  126 . Hence, any or all of the signal conductors  126  can be thicker than those illustrated. Further, the spacing between each of the signal conductors  126  can be greater or less than illustrated, and need not be constant across all angles (i.e. some signal conductors  126  may be closer together than others).  
         [0056]    [0056]FIG. 3A is a diagram illustrating a top view of one embodiment of the second circuit board  104 , showing how signal traces  120 A and  120 B can be routed to and from the connector  106 . For purposes of illustration, the signal traces  120  on the second circuit board  104  are presented. As illustrated, the circuit board  104  can be a multi-layer circuit board, with signal traces on different layers.  
         [0057]    [0057]FIG. 3B is a diagram illustrating a top view of one embodiment of the first circuit board  102 , showing how signal traces  118 A and  118 B can be routed to and from the connector  106 . In this embodiment, the aperture  108  comprises a plurality of concave portions  302  which can be formed from plated vias. These concave portions (which include aperture conductive surfaces  116 ) or partial vias or plated through-holes can be formed by drilling through holes, and cutting through the through holes to form the aperture  108 , and plating the inner surfaces of the concave remainder from the through holes to make electrical contact with the inner layers of the circuit board  102 . Alternatively, the through holes can be plated first, then cut to form the aperture  108 .  
         [0058]    [0058]FIG. 4 is another diagram illustrating a top view of one embodiment of the first circuit board and aperture.  
         [0059]    [0059]FIG. 5 is a diagram presenting another embodiment of the present invention. This embodiment comprises a right angle or “L” shaped connector  106 R disposed between the first circuit board  102  and the second circuit board  104 . This embodiment is useful in applications where electrical connection is required between circuit boards that are disposed approximately 90 degrees from one another, such as with a backplane circuit board and a component circuit board or a mother board and component boards. In this embodiment, the angle connector  106 R comprises a housing  124 R having a plurality of right angle signal conductors  126 AR and  126 BR (hereinafter alternatively collectively referred to as right angle signal conductor(s)  126 R) disposed on the periphery of the housing. Each of the signal conductors  126 R include a first portion  128 R with a spring structure and a second portion  130  for communicatively coupling to the second circuit board  104 .  
         [0060]    [0060]FIG. 6 is a diagram presenting another embodiment of the present invention. In this embodiment, a conductive shield  602  is placed between the first circuit board  102  and the second circuit board  104  and surrounding the connector  106 . The shield  602  is communicatively coupled to a conductive surface  604  on the first circuit board  102  and a conductive surface  606  on the second circuit board  104 . The conductive surfaces can be communicatively coupled to ground planes or other circuit elements in the first circuit board  102  and/or the second circuit board  104  to reduce signals and noise emanating from the connector  106  and or entering the connector  106 .  
         [0061]    [0061]FIGS. 7A and 7B are diagrams of another embodiment of the present invention. In the embodiments described above, spring members are used to contact the inner side of an aperture in the first circuit board  102  and a different contact structure is used for electrical coupling with the second circuit board  104 . FIG. 7A is a diagram of an embodiment in which the connector  106  includes spring contacts on both ends. In this embodiment, both the first circuit board  102  and the second circuit board  104  would include an aperture having conductive surfaces. The assembly can then be held in place with one or more standoffs, fasteners, or similar devices. In one embodiment, the housing  702  includes a lip  702  or similar structure which prevents the first circuit board  102  and the second circuit board  704  from coming together. Standoffs can also be placed between the first circuit board  102  and the second circuit board  104  for this purpose.  
         [0062]    Although the illustrated embodiment depict a system wherein spring structures on the connector effect contact with conductive surfaces on one of the circuit boards, the present invention can be implemented without such spring structures, or can be implemented with spring structures disposed on the circuit board, rather than the connector.  
       Conclusion  
       [0063]    This concludes the description of the preferred embodiments of the present invention. The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

Technology Classification (CPC): 7