Abstract:
A joint connector is provided to shorten the connection length of interface so as to improve the noises caused by the length. The joint connector has a plurality of slots and at least one electrical contact in each slot. When printed circuit boards are linked together, the corresponding electrical contacts of two printed circuit boards are bonded to each other to serve as a communication interface.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The present invention relates to a joint connector for a board-to-board communication interface of printed circuit boards.  
           [0003]    2. Description of Related Art  
           [0004]    As the operation speed and the pin-count of an electronic component have been increased, it is difficult to control the quality of a signal. Thus, high density interconnect (hereafter HDI) printed circuit board has been developed for high-speed electronic components.  
           [0005]    An electronic component or a normal printed circuit board can be electrically connected to another normal printed circuit board via a connector or a cable. However, a conventional connector or connection cable has a certain length for connection. FIG. 1 illustrates a conventional connection with connector and cable for board-to-board communication between printed circuit boards. At least 4 mm of connection cable  10  must be reserved for a connection interface. The longer the length of the connector or the connection cable is, the more noise the connector or the connection cable generates. Thus, there is a need to overcome the length bottleneck of the connector.  
         SUMMARY OF THE INVENTION  
         [0006]    It is therefore an objective of the present invention to provide a joint connector to shorten the connection length of interface so as to improve the noises caused by the signal through the interface.  
           [0007]    In accordance with the foregoing and other objectives of the present invention, the joint connector includes a plurality of slots and at least one electrical contact in each slot. When printed circuit boards are connected, the electrical contacts of two printed circuit boards are bonded to each other so as to serve as a communication interface.  
           [0008]    It is another objective of the present invention to provide a manufacturing method for the joint connector so as to integrate the same into normal PCB process.  
           [0009]    In accordance with the foregoing another objective of the present invention, a manufacturing method for the joint connector includes forming a plurality of slots in connecting rims of a printed circuit board. Subsequently, a conductive layer is deposited in each slot, and an insulated gap is formed to divide the conductive layer into several electrical contacts.  
           [0010]    According to one preferred embodiments of present invention, a plurality of slots of the joint connectors is formed by cutting or punching the connecting rims. A subsequent conductive layer is deposited in each slot by electroplating and is divided into more than two electrical contacts by removing a portion of the conductive layer by drilling, cutting or punching. The electrical contacts serve as a communication interface between printed circuited boards.  
           [0011]    The present invention is directed to shortening the length of a connection interface so as to reduce noise in high-speed communication. High-speed components can be integrated into a small HDI board, rather than all components being integrated into a bigger HDI board. Thus, manufacturing cost can be reduced because an HDI board with small area is used. The joint connector can also replace the conventional connector in a low pin-count system.  
           [0012]    It is to be understood that both the foregoing general description and the following detailed description are examples, and are intended to provide further explanation of the invention as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,  
         [0014]    [0014]FIG. 1 illustrates a conventional connection with connector and cable for board-to-board communication of printed circuit boards;  
         [0015]    [0015]FIG. 2 illustrates a perspective view of a joint connector according to one preferred embodiment of this invention;  
         [0016]    [0016]FIG. 3 illustrates a perspective view of 2 PCB linked with a joint connector according to one preferred embodiment of this invention;  
         [0017]    [0017]FIG. 4 illustrates a flowchart of manufacturing procedures for a joint connector according to one preferred embodiment of this invention;  
         [0018]    [0018]FIG. 5 illustrates the first step of the manufacturing procedures of joint connector according to one preferred embodiment of this invention;  
         [0019]    [0019]FIG. 6 illustrates the second step of the manufacturing procedures of joint connector according to one preferred embodiment of this invention; and  
         [0020]    [0020]FIG. 7 illustrates the third step of the manufacturing procedures of joint connector according to one preferred embodiment of this invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.  
         [0022]    In order to solve a bottleneck in prior art, the present invention provides a joint connector in connecting rims of the printed circuited boards (hereafter PCB). The joint connector consists of a plurality of slots with electrical contacts inside. When two connectors link together, the electrical contacts are employed to connect two printed circuited boards electrically. The joint connector can avoid noise caused by an impedance mismatch, a parasitic capacitance and a parasitic inductance.  
         [0023]    [0023]FIG. 2 illustrates a perspective view of a joint connector according to one preferred embodiment of this invention. FIG. 2 consists of two PCBs and joint connectors thereof. PCB  11  and PCB  13  can be normal PCBs or HDI PCBs. The electrical contact  12  is a conductive layer deposited by electroplating. Each electrical contact  12  can be electrically connected to its destination according to demand. For example, each electrical contact  12  can be electrically connected to a corresponding circuit and be insulated from each other. A slot  18  of PCB  11  can be connected to a corresponding protrusion  19  of PCB  13  as shown in FIG. 2.  
         [0024]    [0024]FIG. 3 illustrates a perspective view of  2  PCBs linked by a joint connector according to one preferred embodiment of this invention. One end of a circuit  14  printed on board is electrically connected to the electrical contact  12  while the other end is designed according to system demand.  
         [0025]    Referring to FIG. 2 and FIG. 3, a number of the electrical contacts  12  in each slot  18  or a number of the electrical contacts  12  around each protrusion  19  may vary according to system demand. The shape of each slot  18  should compensate for the shape of each corresponding protrusion  19 . The shape of the slot  18  or the protrusion  19  is not limited to a square if the slot  18  can properly connect the protrusion  19 . For instance, the shape of the slot  18  or the protrusion  19  can be a triangle and the electrical contacts  12  of the slot  18  and the protrusion  19  bond with each other.  
         [0026]    In practice, the joint connector is adapted for an interface between high-speed module and low-speed module when the speed of FSB (Font Side Bus) of the system is high, such as FSB is 800 MHz. High speed components, such as CPU, Northbridge Chipset and Graph card, are integrated into a HDI board (illustrated as PCB  11  in FIG. 3) while other components, such as Southbridge Chipset, LAN, I/O circuit and power circuit are integrated in another board (illustrated as PCB  13  in FIG. 3). The joint connector of the present invention is a high-speed interface of good quality.  
         [0027]    In addition to connection structure of two boards in the same plane illustrated in FIG. 3, two boards can be connected with any angle, such as 90 degrees (not illustrated in drawings). Moreover, two fastening devices  15  are used to secure firmly the connection between PCB  11  and PCB  13 .  
         [0028]    The manufacturing method of the joint connector is cutting or punching a connecting rim of a PCB to form a slot of a desired shape. A conductive layer is subsequently deposited in the slot by electroplating. The conductive layer is employed as an electrical contact. After depositing the conductive layer, a circuit layout is printed on a board. Moreover, the conductive layer can be divided into several separate electrical contacts by drilling, cutting or punching insulated gaps within. Thus, the slot can provide more electrical contacts for connection.  
         [0029]    [0029]FIG. 4 illustrates a flowchart of manufacturing procedures for a joint connector according to one preferred embodiment of this invention. The manufacturing procedures consist of three main steps. Step  100  is “forming slots in connecting rims”. Step  200  is “forming a conductive layer in each slot”. Step  300  is “removing a portion of the conductive layer”.  
         [0030]    [0030]FIG. 5 illustrates the first step (step  100  in FIG. 4) of the manufacturing procedures of joint connector according to one preferred embodiment of this invention. The first step is forming slots  24  in a connecting rim  23  of a desired area  22  on a PCB  20  by cutting or punching. A slot  24  can have any shape suitable for connection. In this preferred embodiment of present invention, the slot  24  is square.  
         [0031]    Referring to FIG. 5, the PCB with a joint connector (illustrated as PCB  11  or  13  in FIG. 2) is referred to the area  22  of PCB  20  in FIG. 5. The area  22  includes a finished or unfinished circuit printed on or inside.  
         [0032]    [0032]FIG. 6 illustrates the second step (step  200  in FIG. 4) of the manufacturing procedures of joint connector according to one preferred embodiment of this invention. After forming slots  24  in PCB  20 , conductive layers  26  are formed in slots  24  to connect circuits  28 . The conductive layers  26  can be metal material, such as Cu, Au, Ag, Al, deposited by electroplating.  
         [0033]    The conductive layers  26  formed in step  200  are electrically connected to the finished circuits  28  on PCB  20 . When no circuits are printed prior to step  200 , the circuits  28  need to be printed on PCB  20  to connect with the conductive layers  26 .  
         [0034]    [0034]FIG. 7 illustrates the third step (step  300  in FIG. 4) of the manufacturing procedures of joint connector according to one preferred embodiment of this invention. After forming the conductive layers  26  to connect with circuits  28 , step  300  is employed to remove a portion of the conductive layer  26  so as to increase electrical contacts. Namely, step  300  forms insulated gaps  27  between separate electrical contacts. Insulated gaps  27  are formed by cutting or punching a portion of the conductive layers  26 .  
         [0035]    After insulated gaps  27  are formed, the desired area  22  is cut off from PCB  20  (illustrated in FIG. 5) by cutting or punching. Meanwhile, insulated electrical contacts are formed in the slots  24 .  
         [0036]    Referring to FIG. 7, a distance  31  between two adjacent electrical contacts in different slots is equal to a distance  29  between two adjacent electrical contacts  34  in the same slot. In other words, a distance  31  between two adjacent slots is equal to an inner width  29  of each slot. Further, a distance  29  between two adjacent protrusions  39  is equal to an inner width  31  of a protrusion  39 . A distance  31  between adjacent slots  24  is identical to an inner width  31  of protrusions  39  while a distance  29  between adjacent protrusions  39  is identical to an inner width  29  of a slot  24 .  
         [0037]    Additionally, an interface length of the joint connector is the thickness of the conductive layer. The thickness may be, for example, 0.1 mm. Thus, the joint connector can avoid noise caused by an impedance mismatch, a parasitic capacitance a parasitic inductance.  
         [0038]    The purpose of present invention is to shorten the length of connection interface so as to reduce noise in high-speed communication. High-speed components can be integrated into a small HDI board, rather than all components being integrated into a bigger HDI board. Thus, manufacturing cost can be reduced because an HDI board with small area is used. The joint connector can replace the conventional connector in a low pin-count system.  
         [0039]    It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.