Abstract:
A printed circuit board is disclosed. The board has a first end having a plurality of fingers in a cooperating relationship with a second end of a second adjacent circuit board. The board has a second end having a second plurality of fingers in a cooperating relationship with a first end of a first adjacent circuit board. The board has a first portion of an electrical trace on at least one of the first plurality of fingers positioned to allow an electrical connection to the second end of the second adjacent circuit board, and a second portion of the electrical trace on at least one of the second plurality of fingers positioned to allow an electrical connection to the first end of the first adjacent circuit board.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of U.S. Provisional Patent Application No. 61/385,612 entitled “DIRECT MECHANICAL/ELECTRICAL PRINTED CIRCUIT BOARD INTERFACE,” filed Sep. 23, 2010, the contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This disclosure relates to circuit boards in general and, more particularly to printed circuit board interfaces for LED lighting systems. 
       BACKGROUND OF THE INVENTION 
       [0003]    Both conventional light bulbs and light emitting diodes (LEDs) are sometimes installed along a path or line. For example, aircraft or theatre lighting may be installed along a floor mounted strip. Marker and mood lights may also be installed linearly. Lights can be wired and then attached to a retaining device or installed in a tube, or similar. 
         [0004]    In some cases, incandescent bulbs, LEDs, and other electronic devices are mounted on a printed circuit board (PCB). The various circuit boards may be electrically connected, but in the past this has required substantial additional labor for wiring of the boards. In some cases pins, sliders, or other specialty fasteners are required. 
         [0005]    What is needed is a system for addressing the above and related concerns. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention of the present disclosure, in one aspect thereof comprises a printed circuit board. The printed circuit board has a first end having a plurality of fingers in a cooperating relationship with a second end of a second adjacent circuit board. The board has a second end having a second plurality of fingers in a cooperating relationship with a first end of a first adjacent circuit board. The board also has a first portion of an electrical trace on at least one of the first plurality of fingers positioned to allow an electrical connection to the second end of the second adjacent circuit board, and a second portion of the electrical trace on at least one of the second plurality of fingers positioned to allow an electrical connection to the first end of the first adjacent circuit board. 
         [0007]    In some embodiments the first plurality of fingers cooperates with the second end of the second adjacent circuit board by a friction fit. The board may also have a top side and a bottom side, where the electrical trace runs on the top side of the circuit board. In some embodiments the trace runs on the bottom side of the printed circuit board. The electrical trace may run from the first end of the printed circuit board to the second end of the printed circuit board in a manner accessible to electrical components along the printed circuit board. The components may include at least one light emitting diode (LED). At least one heat sink may also be mounted to the printed circuit board. 
         [0008]    The invention of the present disclosure, in another aspect thereof comprises a method of providing light emitting diode (LED) illumination support. The method includes providing an elongated printed circuit board having a first end and a second end and an upper side and a lower side. A plurality of fingers are formed in the first end and a plurality of fingers are formed in the second end. The fingers of the first end are configured to interlock with a plurality of fingers on a second end of an adjacent substantially identical circuit board. The fingers of the second end are configured to interlock with a plurality of fingers on a first end of an adjacent substantially identical circuit board. The method includes forming a plurality of electrical traces along the elongated body. The method also includes forming first and second terminals for each of the respective electrical traces, the first terminal being formed on one of the plurality of fingers on the first end and the second terminal being formed on one of the plurality of fingers on the second end. Each of the terminals comprises an electrical contact surface on an upper surface of the finger and an electrical contact surface on a lower surface of the finger such that when the fingers are interlocked with adjacent substantially identical circuit boards, the respective electrical contact surfaces will lie adjacent and be accessible from both sides of the circuit board. 
         [0009]    In some embodiments, the method includes soldering at least one of the electrical contacts to the adjacent contact. The method may also include forming a plurality of heat sinks on the elongated body. A plurality of LEDs may be surface mounted on the elongated body and electrically connected to at least one of the plurality of electrical traces. The trace connected to the LEDs may be electrically powered. In one embodiment, the method includes mounting at least one LED controller to the elongated body and providing power thereto using one of the plurality of traces and providing a control signal thereto using another one of the plurality of traces. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a plan view of a printed circuit board according to the present disclosure. 
           [0011]      FIG. 2  is a view of the reverse side of the printed circuit board of  FIG. 1 . 
           [0012]      FIG. 3  is a perspective view of the connecting ends of two adjacent printed circuit boards according to the present disclosure. 
           [0013]      FIG. 4  is a perspective view of the printed circuit boards of  FIG. 3  in a connected configuration. 
           [0014]      FIG. 5  is a perspective view of reverse side of the printed circuit boards of  FIG. 4 . 
           [0015]      FIG. 6  is a plan view of a printed circuit board according to the present disclosure illustrated exemplary placement of light emitting diodes and supporting circuitry. 
           [0016]      FIG. 7  is a plan view of the reverse side of the printed circuit board of  FIG. 6 . 
           [0017]      FIG. 8  is a schematic view of a lighting system utilizing printed circuit boards of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Referring now to  FIG. 1  and  FIG. 2 , front and back plan views, respectively, of a printed circuit board according to the present disclosure is shown. The printed circuit board  100  has a generally elongated body with a front side  102  and a back side  104 . The circuit board  100  also provides a first end  106  and a second end  108 . A plurality of interlockable fingers are provided on each of the respective ends  106 ,  108 . In the present embodiment the first end  106  provides a first finger  110 , a second finger  112  and third finger  114 . The second end  108  provides a fourth finger  116  and a fifth finger  118 . 
         [0019]    Each of the fingers  110 - 118  provide a terminal at the first end  106  and the second end  108  comprising contact plates as described below. Traversing the length of the printed circuit board  100  between the ends  106 ,  108  and the associated terminals are a plurality of electrical pathways. An electrical pathway or trace  120  can be seen traversing the front side  102  between first finger  110  and a portion of fourth finger  116 . On the reverse side  104  pathway  122  can be seen proceeding between a portion of the second finger  112  and the third finger  114 . Pathway  124  can be seen proceeding from a portion of second finger  112  to fifth finger  118 . A fourth pathway  126  can be seen proceeding from third finger  114  to a portion of the fifth finger  118 . It will be appreciated that the traces or pathways  120 - 126  may provide electrical contact points for any devices that may be mounted on the front side  102  or back side  104  of the printed circuit board  100 . The pathways  120 ,  122 ,  124 ,  126  may be copper or another suitable conductive metal. 
         [0020]    In the present embodiment it can be seen that on the back or reverse side  104  of the printed circuit board  100  the pathways  120 - 126  are situated so as to define a clear area  129  to allow for mounting of various electronic devices (not shown). In a similar fashion, the front side  102  of printed circuit board  100  provides an area  128  upon which various electrical devices and components (not shown) may be mounted. 
         [0021]    As described in greater detail below, it is contemplated that a number of substantially identical printed circuit boards  100  may be constructed and interlocked together at the ends  106 ,  108 . Once connected physically, an electrical connection may be completed between adjacent circuit boards. Each of the fingers  110 - 118 , acting as a terminal for the pathways  120 - 126 , provide the ability to complete an electrical connection on either the front side  102  or the back side  104  of the printed circuit board  100 . For example, it can be seen that the first finger  110  provides a contact plate  130  on a front side of the finger  110  and another contact plate  136  on the back side of the finger  110 . Finger  112  provides two contact plates on each side since two pathways  122  and  124  are serviced by the finger  112 . In the present example on the front side of finger  112  are contact plates  138  and  146  corresponding to pathways  122  and  124 , respectively. On the reverse side of the finger  112  contact plates  144  and  152  are provided for pathways  122  and  124 , respectively. Finger  114  provides a contact plate  154  on the front side of the finger  114  servicing pathway  126  and provides another contact plate  160  on the reverse side of finger  114 . 
         [0022]    A similar configuration exists on the second end  108  of printed circuit board  100 . Fourth finger  116  services both pathway  120  and  122  of the second end  108 . The fourth finger  116  provides a contact plate  132  on the front side and a contact plate  134  on the second side to service pathway  120 . Fourth finger  116  provides a contact plate  140  on the front side and a contact plate  142  on the back side for servicing pathway  122 . In a similar manner, fifth finger  118  provides contact plates sufficient to service pathways  124  and  126 . On the front side fifth finger  118  provides a contact plate  148  and a reverse side provides contact plate  150  for servicing pathway  124 . Finally, fifth finger  118  provides contact plate  156  on a front side and contact plate  158  on a rear side for servicing pathway  126 . 
         [0023]    Continuity from the front side  128  to the back side  129  of the printed circuit board  100  may be provided. This will ensure that regardless of upon which side the connections between circuit boards are completed, the entirety of the pathways  120 - 126  will be provided with the associated voltage or signal. Accordingly, in the present embodiment, a number of vias are provided for each of the pathways  120 - 126 . In the present embodiments, pathway  120  is provided with vias  162  and  164  passing through the printed circuit board  100  near finger  110  and finger  116 , respectively. In a similar manner, pathway  122  is provided with via  168  near finger  116  and via  166  near finger  112 . Pathway  124  is provided with via  172  near finger  118  and via  170  near finger  112 . Finally, pathway  126  is provided with via  176  near finger  118  and via  174  near finger  114 . 
         [0024]    Referring now to  FIG. 3 , a perspective view of the connecting ends of two adjacent printed circuit boards is shown. In the present illustration, the two circuit boards  100  and  200  are shown are identical. Therefore, it can be appreciated that the first end  106  of the circuit board  200 , constructed as previously described, will meet with the second end  108  of circuit board  100 . From the perspective view of  FIG. 3 , it can be seen that the circuit boards  100  and  200  provide a certain thickness. This thickness between the front and back sides allow for friction surfaces  202  to be defined between various fingers  110 - 118 . When the respective friction surfaces  202  are engaged by interlocking the respective fingers  110 - 118 , the adjacent boards  100  and  200  will form a single unit with the respective pathways  120 - 126  on each of the boards  100  and  200 , being in a position to be electrically connected. 
         [0025]    Referring now also to  FIG. 4 , a perspective view of the printed circuit boards of  FIG. 3  are shown in a connected configuration. It will be appreciated that contact plates  130  and  132  lie adjacent; as do contact plates  140  and  138 ;  146  and  148 ; and  156  and  154 . In some embodiments the contact plates will be constructed such that electrical connection is made any time the fingers are interlocked as shown in the embodiment of  FIG. 4 . In other embodiments, it may be necessary to install soldering  402  between the respective connections between the contact plates. Application of the soldering  402  may also provide additional mechanical rigidity between adjacent boards. 
         [0026]    Referring now also to  FIG. 5 , the reverse side of the interlocked and connected adjacent circuit boards is shown. On the reverse side of  FIG. 5 , solder connections  402  are again provided. However, the configuration of the printed circuit boards ensure that as long the pathways  120 - 126  are completed on a single side of the printed circuit board, the vias will propagate the signal to the other side. In this way, it can be appreciated that if soldering is needed to complete the connection, it may be done from either or both sides of the printed circuit board, and will still provide a reliable electrical connection. 
         [0027]    Referring now to  FIG. 6 , a plan view of a printed circuit board according to the present disclosure, is shown with exemplary placement of light emitting diodes (LEDs) and supporting circuitry. In the present embodiment the circuit board  100  has been provided with six LEDs  602 . These may be surface-mounted LEDs, pin-mounted, or otherwise. Also on the circuit board, at or near the location of the LEDs  604 , are a number of associated heat sinks  606 . An LED controller  604  may also be provided on the circuit board  100 . 
         [0028]    Referring now also to  FIG. 7 , a plan view of the reverse side of the printed circuit board of  FIG. 6  is shown.  FIGS. 6 and 7  each illustrate how various circuitry components that may be mounted on the front or the reverse side of the printed circuit board  100  through installation of traces and vias can each have access to whatever information, power, or signals are provided on each of the pathways  120 ,  122 ,  124  and  126 . 
         [0029]    Referring now to  FIG. 8 , a schematic view of a lighting system utilizing the printed circuit boards of present disclosure is shown. Here the system  800  comprises a control unit  802 , a data and power bus  804 , and a number of printed circuit boards  100  that have been connected together as previously described. The control computer  802  may be a solid-state, purpose-built device, or some other computing device constructed of off-the-shelf components capable of providing the requisite power and data signals over the data and power bus  804  to the printed circuit boards  100 . Through the control computer  802  various voltages and signals, both analog and digital, may be provided on the data bus  804 , which will then be made available to the various components installed on the linked printed circuit boards  100  through the previously described end connections that will place each of the pathways  120 - 126  of the respective printed circuit board  100  at substantially the same power and voltage level. 
         [0030]    With reference also to previous figures, in one embodiment, pathway  120  is used for providing a DC voltage. This voltage will be available to any device on the PCB  100  that can connect to this pathway. Devices may include, but are not limited to, processors, chips, and LEDs. Pathway  122 ,  124 , and  126  may each be assigned to a specific LED color in some embodiments (for example, pathway  122  assigned to blue, pathway  124  assigned to green, and pathway  126  assigned to red). These pathways may provide an analog or digital signal path to ground, via field effect transistor (FET), for example. In this way, each PCB  100  may provide both power and multiple signal lines to each device mounted thereto. Each power and/or signal voltage may be propagated to neighboring boards via the physical and electrical interface described in the various embodiments of the present disclosure. 
         [0031]    Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.