Abstract:
A present invention provides a printed board connector, a contact thereof and a mating instrument that prevent deterioration of electrical conductivity and spring property of contacts resulting from solder rising and/or flux rising. A printed board connector can be mounted in a printed circuit board and constitutes a mating instrument in connection with a male connector such as an insulation displacement plug. The connector has a housing and a contact arranged in the housing. The contact includes a pair of forks opposing each other, terminals capable of being soldered to the printed circuit board, and a spacer connecting terminals and the pair of forks together. The spacer provides a predetermined distance between terminals and the pair of the forks to prevent solder and/flux from rising to the forks.

Description:
[0001]    This application is based on Patent Application No. 2000-393816 filed Dec. 25, 2000 in Japan, the content of which is incorporated hereinto by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a printed board connector capable of being mated with a male connector such as an insulation displacement plug having a cable, a contact of the printed board connector and a mating instrument. In particular, the present invention relates to improvements in the prevention of deterioration of electrical conductivity and spring property of contacts resulting from solder rising and/or flux rising which may occur when a printed board connector is mounted in a printed circuit board of electronic equipment by soldering.  
           [0004]    2. Description of the Related Art  
           [0005]    In electronic equipment such as cellular telephones, a mating instrument composed of an insulation displacement plug (male connector) and a printed board connector (female connector) is often used to connect two power cables of a speaker, a vibration motor, or the like, to a printed circuit board. In this case, the two power cables are fixed by insulation displacement to the insulation displacement plug respectively. The insulation displacement plug with the cables is mated with the printed board connector mounted in the printed circuit board.  
           [0006]    With reference to FIGS.  4  to  7 , conventional techniques for this kind of connectors will be described.  
           [0007]    [0007]FIG. 4 is a plan view of an insulation displacement plug  10 . FIG. 5 is a sectional view of a conventional printed board connector  20 . Also, FIG. 6 shows that the insulation displacement plug  10  and the printed board connector  20  are mated with each other. FIG. 7 is a conventional contact included in the printed board connector  20 .  
           [0008]    As shown in FIG. 4, the insulation displacement plug  10  includes a plug main body  11  and a pair of insulation displacement contacts  12 . The plug main body  11  is made of an insulated material and has a generally rectangular shape. The insulation displacement contacts  12  are arranged in the plug main body  11 . The insulation displacement contact  12  has a base portion  13 , a pair of side walls  14  extending from the base portion  13 , and a contact portion  15  extending substantially in parallel with the respective side walls  14 . The pair of side walls  14  have slots  16  formed therebetween. Terminals of cables  17  are pressed in the slots  16 . This press-in process removes a part of sheathing  17   a  of each cable  17  to allow a core  17   b  of the cable  17  to come into contact with the corresponding side walls  14 . Each contact portion  15  is exposed from the plug main body  11  and extends along the corresponding side wall of the plug main body  11 . The contact portion  15  is engaged with the corresponding contact of the printed board connector  20 .  
           [0009]    The printed board connector  20  is mounted at a predetermined location of the printed circuit board. As shown in FIGS. 5 and 6, the printed board connector  20  includes a housing  22  having a chamber  21 . The above described insulation displacement plug  10  is fitted into the chamber  21  of the housing  22 . Each side wall of the housing  22  has a recess  23  that receives the corresponding contact portion  15  of the insulation displacement plug  10 . Also, each side wall of the housing  22  has a contact  24  fixed thereto by press-in. The contact  24  is generally L-shaped as shown in FIG. 7. That is, the contact  24  includes a base portion  25 , a pair of forks  26  extending from the base portion  25  substantially in parallel with each other, and a terminal  27  extending from the base portion substantially perpendicular to each fork  26 . The terminal  27  is fixed to the printed circuit board by soldering. Each fork  26  has a substantially triangular projection  28  formed on a side thereof. The projections  28  are used to fix the contact  24  to the housing  22  by press-in.  
           [0010]    When the insulation displacement plug  10  is fitted in the chamber  21  of the printed board connector  20 , the contact portion  15  of the insulation displacement contact  12  is held between the pair of forks  26  of the contact  24 . The contact between the insulation displacement contact  12  and the contact  24  allows an electrical connection between the cable  17  connected to the insulation displacement plug  10  and the printed circuit board.  
           [0011]    In the case of using a mating instrument such as the one described above, a reflow soldering device is often used to mount a printed board connector in a printed circuit board. However, during reflow soldering, surface tension of the solder may cause solder and/or flux to rise from the terminals to the pair of forks.  
           [0012]    That is, if the printed board connector  20  is to be fixed to a printed circuit board, the bottom surface of the terminal  27  (FIG. 7) of the connector  20  is soldered to a predetermined location of the printed circuit board, as described above. At this time, solder (solder alloy) and/or flux supplied to the terminal  27  may rise beyond the base portion  25  and reach the forks  26 , extending substantially perpendicular to the terminal  27 . If the solder rises to the tips of the forks  26 , it may degrade the spring property of the forks  26 . Further, if the flux rises to the tips of the forks  26 , it may deteriorate an electrical conductivity between the insulation displacement contact  12  and the contact  24 .  
           [0013]    The present invention is aimed to overcome the above-described problems and provides a printed board connector, a contact thereof, and a mating instrument that can prevent solder rising and/or flux rising so as to improve the reliability of the electric conductivity between contacts and the spring property of the contacts.  
         SUMMARY OF THE INVENTION  
         [0014]    A first aspect of the present invention relates to a printed board connector capable of being mounted in a printed circuit board. This connector comprises a housing and a contact arranged in the housing. The contact includes a pair of forks opposing each other, a terminal capable of being soldered to the printed circuit board, and a spacer connecting the terminal and the pair of forks together. The spacer provides a predetermined distance between the terminal and the pair of forks to prevent solder and/or flux from rising to the forks. Accordingly, the present invention improves the reliability of the electric conductivity and the spring property of the contact.  
           [0015]    In this specification, the “solder” essentially means both conventional tin/lead solder (Sn/Pb solder) and lead-free solder such as Sn/Ag solder.  
           [0016]    Preferably, the spacer defines a predetermined interval between the terminal and the root of the pair of forks. This is achieved by providing the spacer with at least one folded portion. This configuration effectively prevents the solder rising and/or flux rising toward the forks.  
           [0017]    Preferably, the terminal extend substantially perpendicular to the pair of forks. This enables another connector to engage with the printed board connector mounted in the printed circuit board, from over the printed circuit board.  
           [0018]    Preferably, the spacer includes a base portion, a first intermediate portion, a turn-up portion and a second intermediate portion. The base portion is connected to the pair of forks. The first intermediate portion extends substantially in parallel with the forks from an end of the base portion. The end is opposite the forks. The turn-up portion is connected to the first intermediate portion. The second intermediate portion connects the turn-up portion and the terminal together. The second intermediate portion is farther from the pair of forks than the first intermediate portion. That is, the first intermediate potion is positioned between the forks and the second intermediate portion. In this configuration, solder essentially rises along a rear surface of the second intermediate portion, which is kept away from the forks. Consequently, the solder can be easily kept away from the forks.  
           [0019]    Preferably, spaces are defined between the base portion and the terminal and between the first intermediate portion and the second intermediate portion. These spaces allow solder, which is supplied-between the terminal and the printed circuit board and is likely to travel toward the forks, to be kept away from the forks.  
           [0020]    Preferably, the second intermediate portion is branched in two directions, and the contact has two terminals connected to each branched portion of the second intermediate portion respectively. In this configuration, a predetermined interval is defined between the two terminals. The intervals (areas) allow solder to be kept away from forks.  
           [0021]    Another aspect of the present invention provides a contact for a printed board connector. The contact comprises a pair of forks opposing each other, a terminal capable of being soldered to the printed circuit board, and a spacer connecting the terminal and the pair of forks. The spacer provides a predetermined distance between the terminal and the pair of forks to prevent solder and/or flux from rising to the forks.  
           [0022]    A still another aspect of the present invention provides a mating instrument comprising a male connector and a female connector. The male connector has a contact portion. The female connector has a housing with a chamber which receives the male connector, and a contact arranged in the housing. The contact of the female connector includes a pair of forks opposing each other and capable of holding the contact portion of the male connector therebetween, a terminal capable of being soldered to the printed circuit board, and a spacer connecting the terminal and the pair of forks together. The spacer provides a predetermined distance between the terminal and the pair of forks to prevent solder and/or flux from rising to the forks.  
           [0023]    The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIG. 1 is a perspective view showing an embodiment of a printed board connector according to the present invention;  
         [0025]    [0025]FIG. 2 is a perspective view showing a contact of the printed board connector of FIG. 1;  
         [0026]    [0026]FIG. 3 is a side view of the connector of FIG. 2;  
         [0027]    [0027]FIG. 4 is a plan view of an insulation displacement plug that can be mated with the printed board connector of FIG. 1;  
         [0028]    [0028]FIG. 5 is a plan view showing a conventional printed board connector;  
         [0029]    [0029]FIG. 6 is a sectional view showing the insulation displacement plug of FIG. 4 and the conventional printed board connector of FIG. 5 that are mated with each other; and  
         [0030]    [0030]FIG. 7 is a perspective view showing a contact of the conventional printed board connector. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0031]    An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.  
         [0032]    [0032]FIG. 1 shows an embodiment of a printed board connector  40  according to the present invention, and FIG. 2 shows a contact  50  included in the printed board connector  40 . FIG. 3 is a side view of the contact  50 .  
         [0033]    The printed board connector  40  of FIG. 1 is a female connector that can be mounted in a printed circuit board (not shown) built into electronic equipment such as a cellular telephone. The printed board connector  40  can be mated with, for example, the insulation displacement plug  10  shown in FIG. 4. Accordingly, the printed board connector  40  can constitute a mating instrument according to the present invention, in connection with a male connector such as the insulation displacement plug  10 . The detailed description of the insulation displacement plug  10  is omitted.  
         [0034]    The printed board connector  40  includes a housing  42  having a chamber  41  which receives the male connector. The insulation displacement plug  10  shown in FIG. 4 can be fitted within the chamber  41  of the housing  42 . The housing  42  has a bottom plate  42   a , a pair of side walls  42   b , a front and rear walls  42   c  and  42   d , and the like. The chamber  41  is defined by a bottom plate  42   a , side walls  42   b , a front and rear walls  42   c  and  42   d . Each of the front and rear walls  42   c  and  42   d  of the housing  42  has an opening  43  formed therein to prevent interference with the cables connected to the male connector (insulation displacement plug  10 ). Each of the side walls  42   b  of the housing  42  has a recess  44  formed therein. The recess  44  receives the contact portion of the male connector (contact portion  15  of the insulation displacement plug  10 ).  
         [0035]    Furthermore, contacts  50  are fixed to the respective side walls  42   b  of the housing  42  by press-in as shown in FIGS. 2. Each of the contacts  50  is integrally produced by pressing a conductive material (e.g. copper alloy) in a step-by-step manner. The contact  50  has a generally S-shaped side as shown in FIG. 3. The contact  50  includes a pair of forks  51 , two terminals  52 , and a spacer  53 . The spacer  53  connects the pair of forks  51  and the two terminals  52  together. The contact portion of a male connector such as the insulation displacement plug  10  can be held between the pair of forks  51 . Further, the two terminals  52  can be soldered to the printed circuit board.  
         [0036]    When the insulation displacement plug  10  shown in FIG. 4 is fitted in the chamber  41  of the printed board connector  40 , each contact portion  15  of the insulation displacement plug  10  is held between the pair of forks  51 . The contact between the insulation displacement contact  12  and the contact  50  allows an electrical connection between the cable  17  connected to the insulation displacement plug  10  and the printed circuit board.  
         [0037]    As shown in FIGS. 2 and 3, the spacer  53  includes a base portion  54  connected to the pair of forks  51 . The base portion  54  extends substantially perpendicular to the forks  51 . A first intermediate portion  55  extends from an end of the base portion  54 , the end being opposite the forks  51 . The first intermediate portion  55  extends substantially parallel with the forks  51 . The first intermediate portion  55  extends upward in FIG. 3 to oppose the forks  51 . The first intermediate portion  55  is connected to the turn-up portion  56 . The turn-up portion  56  has a generally semicircular side and connects the first intermediate portion  55  and a second intermediate portion  57 . In comparison with the first intermediate portion  55 , the second intermediate portion  57  is kept away from the pair of forks  51 . That is, the first intermediate portion  55  is positioned between the forks  51  and the second intermediate portion  57 . The second intermediate portion  57  extends substantially in parallel with the first intermediate portion  55  and the forks  51 , near the turn-up portion  56 . As shown in FIG. 2, the second intermediate portion  57  is branched in two directions in its middle. Each of two branched portions  57   a  of the second intermediate portion  57  are connected to the terminal  52 . The terminals  52  extend substantially in parallel with the base portion  54 . That is, the terminals  52  extend substantially perpendicular to the pair of forks  51 .  
         [0038]    As described above, the spacer  53  is bent at transition points between the base portion  54  and the first intermediate portion  55 , between the first intermediate portion  55  and the turn-up portion  56 , and between the turn-up portion  56  and the second intermediate portion  57 .  
         [0039]    Further, a root of two branched portions  57   a  of the second intermediate portion  57  is kept away from each terminal  52  by a predetermined distance in a height direction (extensional direction of forks  51 ). The two branched portions  57   a  of the second intermediate portion  57  are inclined toward the pair of forks  51 , and the terminals  52  are located closer to the pair of forks  51  (housing  41 ) than the second intermediate terminal  57 . When the contact  50  is mounted in the housing  42 , each of the terminals  52  is fitted with a hollow portion  45  (FIG. 1) formed on the bottom of the corresponding side wall  42   b  of the housing  42 . This serves to reduce the area of the printed circuit board in which the printed board connector  40  is mounted.  
         [0040]    Generally triangular projections  58  are formed on the sides of the forks  51  and sides of the first intermediate portion  55 . These projections  58  are used to fix the contact  50  to the housing  42  by press-in.  
         [0041]    If the printed board connector  40  is to be mounted in the printed circuit board, the bottom surfaces  52   a  of the terminals  52  of the contact  50  come into contact with the printed circuit board at predetermined locations. Then, solder (and flux) is supplied between the bottom surface  52   a  of each terminal  52  and the printed circuit board. As described above, the spacer  53  provides a predetermined distance between terminals  52  and forks  51 . As shown in FIG. 3, the distance is equal to the sum of the lengths of the base portion  54 , the first intermediate portion  55 , the turn-up portion  56 , and the second intermediate portion  57 . Further, the spacer  53  defines a predetermined interval h between terminals  52  and a root  51   a  of the pair of forks  51 , thereby preventing the base portion  54  and root  51   a  of the contact  50  from contacting with the printed circuit board. Thus, owing to its surface tension, the solder rises along the rear surface of the second intermediate portion  57  kept away from the forks  51 . Consequently, according to the printed board connector of the present invention, the solder can be kept away from the forks to reliably prevent the solder and/or flux from rising to the pair of forks  51  of the contact  50 .  
         [0042]    Further, as shown in FIG. 3, spaces are formed between the base portion  54  and terminals  52  and between the first intermediate portion  55  and the second intermediate portion  57 . Furthermore, a predetermined interval (space) is defined between the two terminals  52  of the contact  50 . These spaces can keep the solder away from the forks  51  even if the solder is likely to flow toward the forks  51  from between terminals  52  and the printed circuit board.  
         [0043]    Since the terminals  52  of the printed board connector  40  extend substantially perpendicular to the pair of forks  51 , a male connector such as the insulation displacement plug  10  can be mated with the printed board connector  40  mounted in the printed circuit board, from over the printed circuit board.  
         [0044]    In the above described printed board connector  40 , the spacer  53  provides a sufficiently long distance between terminals  52  and the pair of the forks  51 , thereby preventing the solder and/or flux from rising to the forks  51 . Consequently, the present invention can improve the reliability of the electrical connection between the contacts  50  and  12  and the spring property of contacts  50 .  
         [0045]    The spacer  53 , including the base portion  54 , the first intermediate portion  55 , the turn-up portion  56 , and the second intermediate portion  57 , can provide a sufficient length between terminals  52  and the pair of forks  51  without any substantial increase in the mounting area of the connector  40 .  
         [0046]    Further, the predetermined interval h (FIG. 3) between terminals  52  and the root  51   a  of the pair of the forks  51  can be obtained by providing the spacer  53  with at least one bent portion. That is, the first intermediate portion  55  and the turn-up portion  56  can be omitted, and the base portion  54  may be connected directly to the second intermediate portion  57  (branched portion  57   a ). This also prevents the solder and/flux from rising to the forks  51 .  
         [0047]    The present invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and it is the intention, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention.