Abstract:
In a connector for use in an electronic card having a circuit board and a case containing the circuit board, a housing holds a ground connection terminal and a contact. The ground connection terminal has a press-fit portion press-fitted to and held by the housing, a contacting portion connected to the press-fit portion and adapted to be contacted with the case, and a terminal portion connected to the press-fit portion and adapted to be connected to the circuit board. The housing has a guide portion for guiding the contacting portion when the press-fit portion is press-fitted to the housing. The contacting portion is connected to the case with elastic displacement inside the guide portion.

Description:
[0001]     This application claims priority to prior Japanese patent application JP 2005-233988, the disclosure of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to a connector for use with an electronic card called a PC (Portable Computer) card or an Express card and, in particular, to a connector with electrostatic protection.  
         [0003]     An electronic card of the type is disclosed, for example, in Japanese Patent (JP-B) No. 3252257 and comprises a connector to be connected to an electronic apparatus. The connector includes a ground connection terminal as protection against electrostatic charges accumulating on the electronic card. The ground connection terminal has a contacting portion electrically connected to upper and lower covers of the electronic card and a printed board. Therefore, electrostatic charges accumulated on the electronic card are released through the ground connection terminal to a ground of the printed board.  
         [0004]     In the above-mentioned connector, the ground connection terminal is formed by press-bending. Therefore, it is impossible to achieve a sufficiently high contacting force of the contacting portion. Further, the ground connection terminal is provided with a bent portion and a spring portion in the vicinity of the contacting portion but no guide is formed around the bent portion and the spring portion. Therefore, due to variations in an assembling process of the connector or upon reception of mechanical shock, the ground connection terminal may be deformed in a direction other than a contacting direction of the contacting portion, i.e., other than a thickness direction of the card. Further, the contacting portion is formed on a flat surface of the bent portion. Therefore, if an oxide film or the like is formed on a surface of each cover, the contacting portion is contacted with the cover via the oxide film. This results in contact failure.  
         [0005]     Because of the above-mentioned problems, the connector according to the conventional technique is insufficient in contact reliability and stability of ground connection. Further, if a mounting height of the connector with respect to the printed board is changed, i.e., if a position of the connector in a thickness direction of the card is changed, it is necessary to change a press-bending process and a punching process for a SMT soldering portion of a ground member. This requires much time and labor and high cost for reconstruction.  
       SUMMARY OF THE INVENTION  
       [0006]     It is therefore an object of this invention to provide a connector improved in reliability of electrostatic protection.  
         [0007]     It is another object of this invention to provide a connector with electrostatic protection, which is flexibly adaptable to various mounting heights.  
         [0008]     It is still another object of this invention to provide an electronic card including the above-mentioned connector.  
         [0009]     Other objects of the present invention will become clear as the description proceeds.  
         [0010]     According to an aspect of the present invention, there is provided a connector for use in an electronic card comprising a circuit board and a case containing the circuit board. The connector comprises a ground connection terminal, a contact, and a housing holding the ground connection terminal and the contact, the ground connection terminal having a press-fit portion press-fitted to and held by the housing, a contacting portion connected to the press-fit portion and adapted to be contacted with the case, and a terminal portion connected to the press-fit portion and adapted to be connected to the circuit board, the housing having a guide portion for guiding the contacting portion when the press-fit portion is press-fitted to the housing, the contacting portion being connected to the case with elastic displacement inside the guide portion.  
         [0011]     According to another aspect of the present invention, there is provided an electronic card comprising a circuit board, a case containing the circuit board, and the above-mentioned connector coupled to the case. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0012]      FIG. 1  is a perspective view of an electronic card according to an embodiment of this invention in a disassembled state;  
         [0013]      FIG. 2  is an exploded perspective view of a connector in the electronic card illustrated in  FIG. 1 ;  
         [0014]      FIG. 3  is a plan view showing a characteristic part of a printed board in the electronic card illustrated in  FIG. 1 ; and  
         [0015]      FIG. 4  is a sectional view of a part of the electronic card in  FIG. 1  in an assembled state. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     Referring to  FIG. 1 , description will be made about an electronic card according to an embodiment of this invention. For convenience of description, a left side of the electronic card in  FIG. 1  will be called a front side while a right side with a connector equipped will be called a rear side.  
         [0017]     The electronic card is depicted by a reference numeral  101  and comprises a connector  10 , a metallic top cover  20 , a metallic bottom cover  30 , and a circuit board or a printed board  40 . The top cover  20  and the bottom cover  30  are fixed to each other after the connector  10  and the printed board  40  are incorporated therebetween. Thus, the electronic card  101  generally in the form of a thin plate is produced.  
         [0018]     The top cover  20  has a U-shaped section and comprises a top portion  21  and a pair of side plates  22  on opposite side of the top portion  21 . The top portion  21  of the top cover  20  has a recessed plane portion  23  formed on an outer surface thereof. The recessed plane portion  23  may be used to receive a label attached thereto.  
         [0019]     The bottom cover  30  comprises an insulating front plate  31 , a bottom portion  34 , and a pair of side plates  32  formed on opposite sides of the bottom portion  34 . The bottom portion  34  has a recessed plane portion  35  formed on an inner surface thereof. The bottom cover  30  further has a platform portion  34   a  protuberating from the bottom portion  34  to form a step and a pair of positioning members  36  disposed adjacent to the side plates  32  to position the printed board  40 . The front plate  31  has a pair of recessed portions  31   a  formed on opposite front sides thereof, respectively.  
         [0020]     Referring to  FIG. 2  in addition, the connector  10  will be described in detail.  
         [0021]     The connector  10  comprises an insulating housing  2  having a flat rear plate  1  formed outside. The housing  2  has a pair of protruding members  3  formed on opposite sides thereof. The connector  10  further comprises a plurality of signal connection terminals or contacts  4  planted in an intermediate portion on a front side (inner side) of the housing  2  and arranged in parallel to one another in a widthwise direction of the electronic card  101 , i.e., a transversal direction in  FIG. 2  and a pair of ground connection terminals (hereinafter referred to as ground lugs)  5  disposed on opposite sides of the housing  2 .  
         [0022]     Each of the contacts  4  has a soldering terminal portion  4   a.  Each of the protruding members  3  of the housing  2  has a holding groove  3   a  formed on the inner side thereof and a pair of guide grooves  3   b  formed on upper and lower sides thereof, respectively.  
         [0023]     Each ground lug  5  is formed by press-punching a metal plate. Each ground lug  5  has a press-fit portion  5   a  extending from a base portion  5   g  and a pair of spring portions  5   d  extending from the base portion  5   g  on opposite sides of the press-fit portion  5   a.  The spring portions  5   d  extend in parallel to the press-fit portion  5   a.  The spring portions  5   d  extend beyond the press-fit portion  5   a  and have contacting portions  5   b  and  5   c  formed on their ends, respectively. In other words, each of the contacting portions  5   b  and  5   c  is connected to the press-fit portion  5   a  through the base portion  5   g  and each of the spring portions  5   d.    
         [0024]     A terminal portion  5   f  extends from the base portion  5   g  in a direction opposite to the press-fit portion  5   a  and the spring portions  5   d.  In other words, the terminal portion  5   f  is connected to the press-fit portion  5   a  through the base portion  5   g.  The terminal portion  5   f  has a lower surface serving as a soldering terminal portion (mounting portion)  5   e.    
         [0025]     The ground lugs  5  are positioned on opposite sides of an array of the contacts  4 . The press-fit portions  5   a  are press-fitted into the holding grooves  3   a  of the housing  2  to be fixed to the housing  2 . The contacting portions  5   b  and  5   c  of the ground lugs  5  are located in the guide grooves  3   b  of the housing  2  and freely movable inside the guide grooves  3   b  in a vertical direction or a card thickness direction. The spring portions  5   d  of the ground lugs  5  are also guided by the guide grooves  3   b  of the housing  2  so that the spring portions  5   d  are displaceable in the vertical direction but are prevented from being deformed in the transversal direction.  
         [0026]     Referring to  FIG. 3 , the printed board  40  will be described.  
         [0027]     The printed board  40  has a plurality of signal pads  41  formed on a surface of its one end and corresponding in position and number to the contacts  4 , and a pair of ground pads  42  formed outside the signal pads  41  and corresponding in position to the ground lugs  5 . The signal pads  41  are connected by soldering to the soldering terminal portions  4   a  of the contacts  4 , respectively. On the other hand, the ground pads  42  are soldered to the soldering terminal portions  5   e  of the ground lugs  5 , respectively.  
         [0028]     Referring to  FIG. 4 , description will be made of a relationship among the ground lugs  5 , the printed board  40 , and the top and the bottom covers  20  and  30 .  
         [0029]     The soldering portions  5   e  of the ground lugs  5  are soldered to the ground pads  42  of the printed board  40 , respectively. One contacting portion  5   b  of each ground lug  5  is contacted with the top cover  20  while the other contacting portion  5   c  of each ground lug  5  is contacted with the bottom cover  30 . Under spring force of the spring portions  5   d,  these contacting portions  5   b  and  5   c  are pressed from inside to outside in the card thickness direction against the top cover  20  and the bottom cover  30 , respectively.  
         [0030]     Since the ground lugs  5  are formed by press-punching, the spring portions  5   d  have a high spring constant. Therefore, the contacting portions  5   b  and  5   c  can be brought into contact with the top and the bottom covers  20  and  30  with sufficient contacting force. Thus, reliability of contact is high.  
         [0031]     In the contacting portions  5   b  and  5   c,  those parts actually contacted with the top and the bottom covers  20  and  30  are fracture surfaces formed by press-punching and have a sharp-pointed shape. Therefore, even if an oxide film or the like is formed on a contacting portion of each of the top and the bottom covers  20  and  30 , reliable electric connection is established without being affected by the oxide film.  
         [0032]     In the soldering portion  5   e  also, a fracture surface formed by press-punching serves as a contacting surface to be contacted with the printed board  40 . Therefore, even if a mounting height in the card thickness direction is changed, a position of the contacting surface to be contacted with the pad can be changed simply by changing a press-punching pattern. Therefore, it is possible to reduce time and labor as well as a cost for reconstruction of a press die.  
         [0033]     Further, the contacting portions  5   b  and  5   c  and the spring portions  5   d  of the ground lugs  5  are prevented by the guide grooves  3   b  of the housing  2  from being deformed in the transversal direction. Therefore, even upon occurrence of variations in a card assembling process or upon reception of mechanical shock, ideal spring deformation is always assured and stable contacting force can be achieved.  
         [0034]     With the electronic card  101  mentioned above, it is possible to always reliably release electrostatic charges accumulated on the covers to a ground of the printed board without being affected by a surface condition of the covers contacted with the contacting portions  5   b  and  5   c  or variations in the production process. In the ground lug  5 , the contacting surface of the soldering portion  5   e  to be soldered to the printed board  40  is formed by a fracture surface obtained by press-punching. Therefore, even if the mounting height of the connector  10  with respect to the printed board  40  is changed, it is possible to easily meet such change simply by modifying a size of the terminal portion  5   f  in a widthwise direction (vertical direction in  FIG. 4 ) to thereby change a position of the soldering portion  5   e,  i.e., simply by changing a press-punching pattern. Therefore, time and labor as well as a cost for reconstruction can be reduced.  
         [0035]     The above-mentioned electronic card may be implemented as a PC card, an Express card known in the art, and so on for use with a notebook-type personal computer.  
         [0036]     Although this invention has been described in conjunction with a preferred embodiment thereof, this invention may be modified in various other manners within the scope of the appended claims.