Abstract:
There is disclosed a printed board connector which inhibits flux from rising in a housing by means of a capillary phenomenon, prevents contacts from being solidified and also prevents solder bridges from being generated. Stands are provided on opposite sides of an under surface of the housing to form an under space common to terminal portions of contacts between the opposite stands.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a printed board connector for making an electrical connection with a printed board. 
     2. Description of the Related Art 
     The connector has multiple terminals. A conventional terminal portion of a contact to be connected to a printed circuit on the printed board is not disposed a sufficient space apart from other members. Therefore, at the time of soldering, solder flux flows into the space and causes various problems. For example, as shown in a front view of FIG. 6 and a side view of FIG. 7, a conventional connector is provided with a rectangular parallelepiped housing  1 . In the housing  1 , female contacts  2  are provided in the front and in the rear as seen in FIG.  6 . Plural pairs of the front and rear female contacts  2  are arranged transversely in parallel. 
     In a fixed portion  3 A formed below a contact portion  3 , the female contact  2  is pressed into and fixed in a press-in hole  4 A of a terminal press-in section  4  which is provided substantially in a central portion along the height of the housing  1 . On a terminal portion  5  linearly extended from the fixed portion  3 A a terminal leg  5 A is formed which is bent orthogonally toward the outside of the housing  1  from a substantially central portion of the terminal portion  5 . 
     Numeral  7  denotes isolation walls which are formed by extended portions of front and rear side walls  1 A and extended to under end surfaces  7 A of the housing  1 . The terminal leg  5 A is drawn to the outside from a pull-out groove  8  which is formed between the isolation walls  7 . The housing  1  is set on an upper surface of a printed board P. The terminal leg  5 A of the female contact  2  is soldered to a printed circuit which is formed on the upper surface of the printed board P. 
     However, when the housing  1  is set on the printed board P, the under end surfaces  7 A of the isolation walls  7  abut on the upper surface of the printed board P. Additionally, both end faces of the terminal leg  5 A of the female contact  2  are in contact with or adjacent to both side surfaces  8 A of the pull-out groove  8 . Also, an upper surface  5 B of wind portion of the terminal leg  5 A is also in contact with or adjacent to an upper wall surface  8 B of the pull-out groove  8 . 
     Therefore, when the terminal leg  5 A is soldered to the printed circuit of the printed board P, flux enters the housing  1  via small clearances between the both side surfaces  8 A of the pull-out groove  8  and both end faces of the terminal leg  5 A and between the upper wall surface  8 B and the upper surface  5 B of the wind portion. Further, the flux rises along a contact portion between an inner wall surface  1 B of the housing  1  and the terminal portion  5  by means of capillary phenomenon. The flux climbs up to an under surface of the terminal press-in section  4  which forms an upper portion of the terminal portion  5 . 
     Also, the female contact  2  is mounted in the housing  1  by cutting the female contact  2  from its carrier and subsequently pressing the female contact  2  into the press-in hole  4 A of the terminal press-in section  4 . Further, the terminal leg  5 A is folded and bent orthogonally toward the outside by using as a guide the under end surface of the upper wall surface  8 B of the pull-out groove  8 . The terminal leg  5 A is thus drawn from the pull-out groove  8  toward the outside. In this case, dispersion arises in the folding and bending angle of the terminal leg  5 A. It is difficult to control dimensions of the terminal legs. 
     Therefore, since a condition of contact with the printed board is varied, soldering is performed non-uniformly. In some case, a connection defect is caused. 
     The terminal portion  5  of the female contact  2  has an non-plated broken section which is made by cutting the female contact  2  from the carrier. Also, the terminal leg  5 A is scratched at the time of a bending process. Therefore, the soldered condition is improper. Further, in some cases the rising flux sticks to the contact portion  3 . The movement of the contact portion  3  is restricted. An inserting/pulling force is difficult exerted at the time of engagement with male terminals and at the time of pulling male contacts. 
     Further, solder (solder paste) passes through the clearance between the under end surface  7 A of the isolation wall  7  and the upper surface of the printed board P to short-circuit the adjoining left and right terminal legs  5 A. In some cases, a so-called soldered bridge is formed. 
     Also, in the conventional connector of FIG. 6, a slope  2 A of a male contact insertion portion on a head of the female contact  2  is positioned as high as an insertion slope  1 D of the housing  1 . Therefore, a tilted tip end of the male contact abuts directly on the slope  2 A, thereby damaging the female contact  2 . When the female contact is repeatedly inserted and pulled out, the tilt is gradually changed. An engagement force of the male contact and the female contact is changed accordingly. Also, right and left holding forces of the tuning-fork shaped right and left contact portions  3  of the female contact are also changed. This easily occurs also when a center line of the slope  2 A is not positioned precisely. 
     An object of the present invention is to solve the aforementioned conventional problems caused by the sticking and rising of the flux. 
     SUMMARY OF THE INVENTION 
     To solve this and other objects, in the invention, in an under portion of a housing in which plural contacts having terminal portions extended downward to contact a printed board are held, an under space common to the terminal portions is formed by disposing stands on both side wall ends. The flux is thus prevented from sticking and rising. 
     Also, in the case that, in the under space, the terminal portions of the plural contacts are folded, bent and pulled out in a position apart from an under surface of the housing, the flux can be more effectively prevented from sticking and rising. Further, by using as a reference surface one side face of a held portion or fixed portion of the contact, the contact is pressed into and held in a press-in hole of the housing. Then, a position of a center line of a tip-end slope can be precisely maintained. 
     Also, a head slope of a female contact as a female connector having a tuning-fork shaped contact portion deviates below an insertion slope of the housing. Then, the male contact can be prevented from damaging the female contact. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a female connector and a male connector for a printed board according to an embodiment of the invention. 
     FIG. 2 is a plan view of the female connector shown in FIG.  1 . 
     FIG. 3 is a sectional view taken along line II—II of FIG.  2 . 
     FIG. 4 is a sectional view taken along line III—III of FIG.  3 . 
     FIG. 5 is a perspective view of a female contact for use in the embodiment. 
     FIG. 6 is a front view of a conventional female connector. 
     FIG. 7 is a partly cut-away side view of the female connector of FIG.  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the invention will be described in detail with reference to FIGS. 1 to  5 . In the figures, “A” denotes a female connector for a printed board according to the embodiment. A terminal press-in section  10  (FIGS. 3 and 4) is formed in an under portion of a rectangular parallelepiped housing  9 . Additionally, a pair of right and left stands  11  (FIGS. 1 to  3 ) are integrally formed on both end portions of an under surface of the housing  9 , extending in a depth direction (in a front to rear direction). 
     Therefore, when the female connector A is mounted on a printed board P via both the stands  11  of the housing  9 , between an under surface of the terminal press-in section  10  between the stands  11  and an upper surface of the printed board P, an under space  12  is formed at a height of the stand  11 . 
     Numeral  13  denotes side walls for left and right sides of the housing  9 . In upper portions of the side walls  13 , four open space portions  15  are defined at a depth to the upper surface of the terminal press-in section  10  by partition walls  14  which are parallel with the side walls  13 . Also, in the open space portions  15  inside side walls  16  for front and rear sides of the housing  9 , side wall blocks  17  are arranged parallel with the side walls  16 . Between the side wall block  17  and the opposed side wall  16 , a setting groove  18  for a female contact  22  described later is formed a little deeper than the upper surface of the terminal press-in section  10 . Additionally, the under portion of the setting groove  18  is connected to the under space  12  via an insertion hole  19  which is vertically extended through the terminal press-in section  10 . 
     Numeral  20  denotes a cutting groove which is vertically formed in a central portion between the opposed side walls  16  and between the opposed side wall blocks  17 . The cutting groove  20  has the same depth as the setting groove  18 . Opposed upper corners of the cutting groove  20  are chamfered obliquely to form insertion slopes  21  on the housing. As shown in FIG. 5, the female contact  22  is a metal plate having elasticity formed into a tuning fork shape. The female contact  22  is provided with an upper half portion of a rectangular contact portion  23 , an intermediate portion of a fixed portion  22 A and a under half portion of a thin-strip terminal portion  24 . The contact portion  23  is branched into two toward its tip end and given elasticity. As seen from FIG. 3, slopes  23 A of male contact insertion portions are formed on opposed faces of a head of the contact portion  23 . The opposed faces serve as contact portions. The slopes  23 A are deviated downward by a distance D shown in FIG. 3 from the housing insertion slopes  21 . Thereby, male contacts  27  are guided by the housing insertion slopes  21  before reaching the slopes  23 A. Therefore, the contact portions  23  avoid being damaged. 
     Also, the terminal portion  24  is bent orthogonally from an under end of the fixed portion  22 A to the contact portion  23 . 
     Here, the terminal portion  24  of the female contact  22  is bent through a tip bending process by means of a press, and then plated. Thereafter, the fixed portion  22 A of the female contact  22  is cut from the carrier. Therefore, the female contact  22  has a good bending precision. When terminals are inserted to the housing  9  as described later, floating of the housing  9  from an under end surface  9 A of the terminal press-in section  10  can be controlled. Also, no scratches are made on a bent portion  24 A of the terminal portion  24  during the bending process. Additionally, a tip-end surface of the terminal portion  24  is also plated, so soldering is performed effectively. 
     The contact portion  23  of the female contact  22  is then inserted from the under end surface  9 A of the housing  9  into the setting groove  18  of the housing  9 . The fixed portion  22 A is fixed in the insertion hole  19  of the terminal press-in section  10 . As shown in FIGS. 3 and 5, one side of the fixed portion  22 A of the female contact  22  is used as a reference surface  22 B, while an opposite surface  22 C is partially formed in an arrowhead shape. After insertion, the female contact  22  is prevented from being deviated from its center by the reference surface  22 B. The terminal portion  24  is drawn horizontally from the under space  12  of the terminal press-in section  10  to the outside. In this case, in the under space  12  the under end surface  9 A of the terminal press-in section  10  is not in contact with the upper surface  24 A of the bent portion of the terminal portion  24 . Additionally, a space is formed between the terminal portions  24  which are drawn parallel with each other from the under space  12  to the outside. 
     In FIG. 1, numeral  25  denotes a rectangular parallelepiped male connector which can be engaged with the female connector A. In an under portion of the male connector  25  an inner space portion  26  is provided for engaging with the housing  9  of the female connector A. Inside the inner space portion  26  the male contacts  27  are positioned opposite to the female contacts  22  of the female connector A. Numeral  28  denotes contact portions of the male contacts  27 . On right and left side wall rims  29 A of a housing  29  legs  29 B are formed for fixing the male connector  25  to an opposed printed board. 
     The female connector A constituted as described above is then mounted on the printed board P via the stands  11  on opposite under ends of the housing  9 . The female connector A is fixed to the printed board P with pins  11 A protruding from under surfaces of the stands  11  in the same manner as in the conventional art. At this time, the under space  12  is formed as high as the stands  11  between the under surface of the terminal press-in section  10  between the opposite stands  11  and the printed board P. 
     Subsequently, the terminal portions  24  protruding horizontally from the under space  12  to the outside are soldered to the printed circuit of the printed board P. In this case, the under end surface  9 A of the housing  9 , i.e., the under end surface  9 A of the terminal press-in section  10  does not abut on the upper surface of the bent portion  24 A of the terminal portion  24 . Additionally, the terminal press-in section  10  is formed in the under portion of the housing  9 . Therefore, the flux is inhibited from rising upward from the terminal press-in portion  10  in the housing  9 . 
     Additionally, in the female connector A, between the under end surface  9 A of the housing  9  and the upper surface of the printed board P is formed the under space  12 . Specifically, the under end surface  9 A is mounted above the upper surface of the printed board P. Therefore, the under end surface  9 A of the housing  9  does not ride on a soldered base which is printed on the printed circuit of the printed board P. The soldered bridge is reliably prevented from occurring between the terminal portions  24 . 
     Subsequently, when the inner space portion  26  of the male connector  25  is engaged with the housing  9  of the female connector A, the male contacts  27  are guided by the housing slopes  21  and the slopes  23 A of the female contacts  22 . The contact portions  28  of the male contacts  27  are inserted in the contact portions  23  of the female contacts  22  for electrical connection.