Patent Publication Number: US-6986671-B2

Title: Board mounted electrical connector assembly

Description:
FIELD OF THE INVENTION 
     This invention generally relates to the art of electrical connectors and, particularly, to an electrical connector assembly which includes a header connector mounted on one side of a printed circuit board for mating, through the board, with a second connector on an opposite side of the board. 
     BACKGROUND OF THE INVENTION 
     Electrical connectors are mounted on printed circuit boards in a wide variety of applications. In some instances, an electrical connector simply is mounted to a surface of the printed circuit board, and the connector includes a plurality of terminals having tail portions for connection, as by soldering, to appropriate circuit traces on the board. In other applications, the electrical connector not only is mounted to a surface on one side of the circuit board, but the connector mates through the board with a second connector on an opposite side of the board. Typically, with such “through mating” connector assemblies, a “blind” mating situation occurs because a user or operator can neither see nor feel one of the connectors on a side of the circuit board opposite the location of the user. In such blind mating assemblies, one of the connectors typically has a guide post insertable into a guide hole in the other connector for guiding the connectors into mating alignment to facilitate the blind mating process. 
     Various problems occur in designing blind-mating, through-board connector assemblies as described above. One problem concerns the length of the guide posts which typically are on the blind mating connector. It is highly desirable to reduce the length of the guide posts as much as possible to prevent stubbing, breakage or the like. In addition, the guide posts often extend completely through the printed circuit board and beyond a rear side of the board-mounted connector on the opposite side of the board. Conserving space behind the connector for other electronic components is critical in some miniaturized situations and, again, reducing the length of the guide posts is not only desirable but quite important. The present invention is directed to solving these various problems. 
     SUMMARY OF THE INVENTION 
     An object, therefore, of the invention is to provide a new and improved connector assembly for mating through a printed circuit board. 
     In the exemplary embodiment of the invention, an electrical connector is provided for mounting on a printed circuit board which includes a mounting surface, an opposite mating surface, a locating hole and a terminal-receiving aperture. The connector includes a dielectric housing having a front board-mounting face for mounting against the mounting surface of the printed circuit board. At least one terminal-receiving passage in the housing has a front opening in the front board-mounting face of the housing, with the front opening alignable with the terminal-receiving aperture in the printed circuit board. An alignment boss projects from the front board-mounting face of the housing and is insertable into the locating hole in the printed circuit board. The alignment boss has a guide hole for receiving a guide post from a complementary mating connector at the mating surface of the printed circuit board. A conductive terminal is mounted on the housing and includes a tail portion outside the housing for connection to an appropriate circuit trace on the printed circuit board. The terminal includes a contact portion inside the terminal-receiving passage of the housing for engaging an appropriate terminal of the complementary mating connector. 
     According to one aspect of the invention, the alignment boss projects through the locating hole in the printed circuit board from the mounting surface of the board to a location generally flush with the mating surface of the board. The guide hole of the alignment boss has a flared mouth to facilitate inserting the guide post of the complementary mating connector into the guide hole. 
     According to another aspect of the invention, the dielectric housing is elongated and includes a pair of the alignment bosses near opposite ends of the elongated housing, the bosses being insertable into a pair of spaced locating holes in the printed circuit board. A row of the terminal-receiving passages are provided in the housing, the row extending in a direction between the pair of alignment bosses. A plurality of the conductive terminals are mounted on the housing, with the terminals having contact portions in the plurality of terminal-receiving passages. The row of passages are aligned with an elongated slot in the printed circuit board. 
     A further feature of the invention includes at least one flexible latch arm on the connector housing engageable in a latch opening in the printed circuit board. 
     The invention contemplates a connector assembly which includes the electrical connector described above in combination with a printed circuit board having the mounting surface, the opposite mating surface, the locating hole and the terminal-receiving aperture therethrough. The invention also contemplates an assembly which includes the electrical connector described above, in combination with the mating connector having one or more guide posts. 
     Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
         FIG. 1  is a perspective view of an electrical connector system embodying the concepts of the invention; 
         FIG. 2  is a perspective view of the printed circuit board shown in  FIG. 1 ; 
         FIG. 3  is a perspective view of the header connector mounted to a mounting surface of the printed circuit board; 
         FIG. 4  is a perspective view of the header connector mounted to the printed circuit board, and looking at the mating surface of the board; 
         FIG. 5  is a view similar to that of  FIG. 4 , but looking at the mounting surface of the board and the rear face of the header connector; and 
         FIG. 6  is a perspective view of the second or mating connector shown in  FIG. 1  which mates with the header connector of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings in greater detail, and first to  FIG. 1 , the invention is incorporated in an electrical connector system, generally designated  10 , which includes a printed circuit board  12  which is the center of a blind-mating connector arrangement. Specifically, the printed circuit board has a mounting surface  12   a  and an opposite mating surface  12   b . A header connector, generally designated  14  (also see  FIG. 3 ), is mounted to mounting surface  12   a  of the circuit board, and a complementary mating connector, generally designated  16 , is blind mated with header connector  14  in the direction of double-headed arrow “A” Mating connector  16  is part of an overall mating connector arrangement, generally designated  18 . 
     Referring to  FIG. 2  in conjunction with  FIG. 1 , printed circuit board  12  includes a pair of spaced locating holes  20  and an elongated terminal-receiving slot  22  extending between the holes. A row of discrete tail-receiving holes  24  extend through the board, the row extending generally parallel to elongated slot  22 . A cut-out or recess  26  is formed in the outside edge of each locating hole  20 . 
     Referring to  FIG. 3 , header connector  14  includes a dielectric housing, generally designated  28 , which is elongated and which may be a one-piece structure unitarily molded of plastic material or the like. The housing has a front board-mounting face  30  for mounting against the mounting surface  12   a  of printed circuit board  12 . The housing also has a rear face  32 . The housing has a row of terminal-receiving passages  34  having front openings  34   a  in a row in the front board-mounting face  30  of the housing. When header connector  14  is mounted to mounting surface  12   a  of the printed circuit board, openings  34   a  of terminal-receiving passages  34  are aligned with the elongated terminal-receiving slot  22  ( FIG. 2 ) in the printed circuit board. 
     Still referring to  FIG. 3 , housing  28  of header connector  14  includes a pair of alignment bosses  36  which project from the front board-mounting face  30 . The bosses are insertable into locating holes  20  ( FIG. 2 ) of the printed circuit board. Each alignment boss  36  has a through guide hole  36   a  for receiving a guide post from mating connector  16 , as described hereinafter. The guide hole has a flared mouth, as at  36   b , to facilitate inserting the guide post into the guide hole. A pair of flexible latch arms  38 , having latch hooks  38   a , project from the board-mounting face of the housing outside each alignment boss  36 . When header connector  14  is mounted to mounting surface  12   a  of the printed circuit board, latch arms  38   a  project through the cut-outs or recesses  26  ( FIG. 2 ) in the printed circuit board. Finally, housing  28  of header connector  14  includes a plurality of upstanding retention teeth  40  which define a plurality of retention slots  42  therebetween, for purposes to be described hereinafter. 
     A plurality of conductive terminals, generally designated  44  ( FIG. 3 ), are mounted on housing  28  of header connector  14 . The terminals are generally U-shaped to define tail portions  44   a  and contact portions (not visible in the drawings) which are bent around rear face  32  of the housing and into passages  34  for engaging the terminals of mating connector  16  ( FIG. 1 ). As can be seen clearly in  FIG. 3 , tail portions  44   a  of the terminals are located within retention slots  42  between retention teeth  40  of the housing. The retention slots have restricted mouths  42   a  past which the tail portions are snapped and securely retained within the slots. 
       FIGS. 4 and 5  show header connector  14  mounted to mounting surface  12   a  of printed circuit board  12 . When securely mounted, the front board-mounting face  30  of connector housing  28  abuts mounting surface  12   a  of the board. Latch arms  38  project through recesses  26  in the board, and latch hooks  38   a  of the latch arms snap into latching engagement with the opposite mating surface  12   b  of the circuit board. Alignment bosses  36  project through locating holes  20  in the circuit board to a location generally flush with mating face  12   b  of the board. Front openings  34   a  of terminal-receiving passages  34  are aligned with elongated terminal-receiving slot  22  in the board. As seen in  FIG. 5 , retention teeth  40  abut against mounting surface  12   a  of the circuit board. As seen in  FIG. 4 , tail portions  44   a  of the terminals project through holes  24  in the circuit board, and the tails are connected, as by soldering, to appropriate circuit traces (not shown) on the board and/or in the holes. 
       FIG. 6  shows mating connector  16  of the overall mating connector arrangement  18  shown in  FIG. 1 . The mating connector can take a variety of configurations. However, the connector shown includes a dielectric housing  50  having a row of terminal pins  52  projecting forwardly thereof. A pair of guide posts  54  are located at opposite ends of the row of terminal pins and project generally parallel thereto. As seen in  FIG. 1 , terminal pins  52  project rearwardly in the overall mating connector arrangement  18  to a second housing or alignment body  56  which aligns a plurality of tail portions  58  of the terminal pins which may be connected, as by soldering, to circuit traces on another printed circuit board (not shown). 
     When mating connector  16  is mated with header connector  14  as represented by double-headed arrow “A” ( FIG. 1 ), terminal pins  52  are inserted through the elongated terminal-receiving slot  22  of printed circuit board  12 , and the terminal pins are inserted through openings  34   a  ( FIG. 3 ) and into terminal-receiving passages  34  of header connector  14 , whereupon the terminal pins engage the contact portions of terminals  44  within the passages. In addition, guide posts  54  of mating connector  16  are inserted into the guide holes  36   a  of alignment bosses  36  of the header connector which is mounted at the opposite side of the circuit board. 
     It should be understood that guide posts  54  must be inserted into the guide holes of the header connector before terminal pins  52  are inserted into passages  34  of the header connector, so that the posts precisely align the terminal pins with the passages to prevent the terminal pins from stubbing on the housing of the header connector. In the prior art, this means that guide posts  54  should be longer than the terminal pins so that the guide posts “mate” before the terminal pins “mate”. However, it should be noted in  FIG. 1  that guide posts  54  are substantially the same length as terminal pins  52 . By extending alignment bosses  36  through the thickness of printed circuit board  12  within locating holes  20 , according to the invention, guide posts  54  can enter guide holes  36   a  before terminal pins  52  enter passages  34 . In other words, the arrangement or system of the present invention achieves the results of the prior art while shortening the length of guide posts  54 . 
     It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.