Patent Publication Number: US-7588443-B2

Title: Board-to-board electrical connector assembly

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to electrical connectors, especially to an electrical connector assembly provided for electrically connection between two circuit boards. 
   2. Description of Related Art 
   A variety of electrical connectors have been used to make electrical connections between the circuits on different printed circuit boards. These printed circuit boards must be joined together with connectors in a manner to effectively and reliably interconnect the circuits on one circuit board to the circuits on another circuit board. This is done by a pair of mating connectors which are surface mounted connectors and may include a male or plug connector mateable with a female or receptacle connector to form a board-to-board electrical connector assembly. 
   As stated above, both connectors of the electrical connector assembly are surface mounted connectors. Both connectors typically have a low profile and have some form of mechanism to hold the connectors together. The holding mechanism preferably aligns the connectors, prevents the two connectors from wobbling and maintains the terminals of the connector in good, positive interengagement. 
   WO Publication No. 2004-10538 A1 discloses a conventional board-to-board connector assembly comprising a first connector engaged with a first PCB, a second connector engaged with the first connector and a second PCB. The first connector comprises a first housing and a plurality of first terminals received in the first housing. The second connector comprises a second housing and a plurality of second terminals received in the second housing. The first terminal is formed a single metallic sheet by stamping and curving. The first terminal comprises an integral spring portion, an inverted U-shaped retaining portion and a soldering portion. The retaining portion defines a first wall, a top portion, a second wall, a first curved portion formed between the first wall and the top portion, and a second curved portion formed between the top portion and the second wall. The second terminal is formed a single metallic sheet by crimping and has a P-shaped cross-sectional configuration. The second terminal comprises a first contacting portion defined a protrusion thereof, a second contacting portion, a top end and a tail portion. When the first and second connectors are assembled each other, the first terminal of the first connector is electrically engaged with the second terminal of the second connector. At this time, the protrusion of the second terminal fixedly locked under a bottom end of the second curved portion of the first terminal and electrically connecting with the second wall of the retaining portion so as to obtain reliable orientation between the first and second connectors. 
   However, because the first terminal is formed a single metallic sheet by stamping and curving, which make the configuration of the first terminal and manufacture of the first terminal are so complicated. Furthermore, when the first connector engages with the second connector, the orientation between the first and second connectors is only obtained by the engagement between the first and second terminals. Which is insufficient to prevent the first and second connectors from wobbling. 
   Therefore, an improved board-to-board connector assembly is desired to overcome the disadvantages of the prior arts. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a board-to-board connector assembly for effecting a connection between two circuit boards. 
   In order to achieve above-mentioned object, an board-to-board connector assembly in accordance with a preferred embodiment of the present invention comprises a first connector and a second connector engaged with the first connector. The first connector comprises a first insulative housing, a plurality of first terminals received in the housing and four first metal ears engaged with corresponding corners of the first housing. The first housing defines a first peripheral wall defining a first opposite longitudinal walls and a second opposite transverse walls connecting with the first longitudinal walls, a main body formed in a middle portion thereof around the first peripheral wall, and two engagement passages formed between the first peripheral wall and the main body. The first longitudinal wall defines a plurality of passageways therethrough, while main body defines a plurality of mounting holes therethrough and connected with the engagement passages. The first terminal comprises a first tail, a first retaining portion secured in the passageway and a first contacting portion received in the mounting hole. 
   The second connector comprises a second insulative housing, a plurality of second terminals received in the housing and a pair of second metal ears engaged with two opposite ends of the housing. The peripheral wall defines a second peripheral wall a second opposite longitudinal walls and a second opposite transverse walls connecting with the second longitudinal walls, and a receiving cavity formed between the second longitudinal and transverse walls. The second longitudinal wall defines a plurality of receiving holes therethrough. The second terminal comprises a second retaining portion, a second contacting portion, a connecting portion connecting the second retaining portion and the second contacting portion, and a second tail soldered onto a printed circuit board. The second terminal also defines a protrusion formed between the connecting portion and the second retaining portion, while the second metal ear defines a block thereof. The first peripheral wall defines a rib and a locking portion on its inner portion toward to the engagement passage, respective engaged with corresponding to the protrusion and the block of the second connector during the first and second connectors engaged each other. 
   Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded, perspective view of a first connector of the connector assembly in accordance with the preferred embodiment of the present invention; 
       FIG. 2  is an assembly view of the first connector of  FIG. 1 ; 
       FIG. 3  is an exploded, perspective view of a second connector of the connector assembly in accordance with the preferred embodiment of the present invention; 
       FIG. 4  is an assembly view of the second connector of  FIG. 3 ; 
       FIG. 5  is an assembly view of the connector assembly; 
       FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 5 ; and 
       FIG. 7  is a cross-sectional view taken along line VII-VII of  FIG. 5 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Reference will now be made to the drawing figures to describe the preferred embodiment of the present invention in detail. 
   Referring to  FIGS. 1-7 , a board-to-board electrical connector assembly provided for electrical connection between a first and second printed circuit board (PCBs) (not shown) in accordance with the preferred embodiment of the present invention comprises a first connector  100  and a second connector  200  engaged with the first connector  100 . 
   Referring to  FIGS. 1 and 2 , the first connector  100  comprises a first housing  10 , a plurality of first terminals  20  received in the first housing  10  and four first metal ears  60  engaged with the first housing  10 . The first housing  10  comprises a first peripheral wall  11 , a rectangular main body  13  formed in a middle portion thereof around the first peripheral wall  11 , and an engagement passage  14  formed between the first peripheral wall  11  and the main body  13 . The first peripheral wall  11  defines an opposite first longitudinal walls  11   a  and an opposite first transverse walls  11   b  connecting with the first longitudinal walls  11   a . The longitudinal wall  11   a  defines a plurality of passageways  113  therethrough and a rib  114  formed on an inner portion thereof toward to the engagement passage  14 . The main body  13  defines a pair of trapeziform recesses  131  at two opposite ends parallel to the first transverse wall  11   b , and a plurality of mounting holes  132  at the other two opposite ends parallel to the first longitudinal wall  11   a , corresponding to the passageway  113 . Both the trapeziform recess  131  and the mounting hole  132  are connected with the engagement passage  14 . The first transverse wall  11   b  defines a slot  115  opposite to the trapeziform recess  131  on an inner portion thereof. A locking portion  116  is formed on inner wall of the slot  115 , for fixedly engaging with the second terminal  40  of the second connector  200 . The first longitudinal wall  11   a  defines a pair of securing recesses  117  at two opposite ends thereof. The securing recess  117  defines a securing portion  118  thereof, for engaging with the first metal ear  60 . 
   Each of the first terminal  20  is formed from a metal sheet by stamping and has an F-shaped cross-sectional configuration. The first terminal  20  comprises a base portion  21  received in the engagement passage  14 , a first retaining portion  22  extending upwardly from a lateral side of the base portion  21  for be received in the passageway  113 , a first contacting portion  23  extending slantly and upwardly from one end of the base portion  21  and received in the mounting hole  132 , and a first tail  24  extending from the opposite end of the base portion  21  for soldering onto the first PCB (not shown). The first retaining portion  22  defines a barb  221  for wedging into the passageway  113 . Both the base portion  21  and the first contacting portion  23  are formed a same side of the first retaining portion  22 , a connecting point  231  is formed at a distal end of the first contacting portion  23  for engaging with the second terminal  40 . 
   Each first metal ear  60  is engaged with the corresponding securing recess  117  of the first longitudinal wall  11   a  and defines a vertical portion  61  having two fixing legs  63  formed at two opposite ends thereof and provided for engaging with the securing portion  118  of the securing recess  117 , a planar portion  62  extending from a bottom end of the vertical portion  61  for soldering the first metal ear onto the first PCB. 
   When in assembly of the first connector  100 , the first terminal  20  is firstly mounted onto the housing  10  from a bottom portion of the housing  10  via the barb  221  of the first retaining portion  22  of the terminal  20  wedging into the corresponding passageway  113  of the housing  10 , at the same time, the first tail  24  of the first terminal  20  is extended outward of the peripheral wall  11  of the housing  10 . Then the four first metal ears  60  are respectively fixed onto the housing  10  via the corresponding the fixing legs  63  interferentially engaged into corresponding securing portions  118  so as to fix the metal ears  60  into the securing recesses  117 , while the planar portion  62  of the first metal ear  60  is also extended outward of the peripheral wall  11  of the housing  10 , together with the first tail  24  of the first terminal  20 , to solder the first connector  100  onto the first PCB. Thus, electrical connection between the first connector  100  and the first PCB is obtained. 
   Referring to  FIGS. 3 and 4 , the second connector  200  comprises a second housing  30 , a plurality of second terminals  40  received in the second housing  30  and a pair of second metal ears  50  engaged with the second housing  30 . The second housing  30  defines a second peripheral wall  31 , a base plate (not shown), and a receiving cavity  33  formed between the peripheral wall  31  and the base plate. The second peripheral wall  31  defines an opposite second longitudinal walls  31   a  and an opposite second transverse walls  31   b  connecting with the second longitudinal walls  31   a . Each of the second longitudinal walls  31   a  defines a plurality of grooves  35  along a longitudinal direction thereof. The second transverse wall  31   b  defines a cutout  311  connecting with the receiving cavity  33  in its inner wall thereof. A T-shaped flange  34  extends from a middle portion of the cutout  311  toward to the receiving cavity  33  and defines a trapeziform portion  342  formed at a front end of the flange  34 . A space  341  is formed between the flange  34  and the inner wall of the cutout  311 . The second transverse wall  31   b  defines a pair of notches  312  corresponding to the cutout  311  on an out wall thereof and a channel  313  connected with the cutout  311  and the notch  312  to fix the second metal ear  50  onto the second housing  30 . 
   Each of second terminal  40  has a P-shaped cross-sectional configuration. The second terminal  40  comprises a second contacting portion  41 , a second retaining portion  42  parallel to the second contacting portion  41 , a connection portion  43  connecting the second contacting portion  41  and the second retaining portion  42 , and a second tail  44  extending parallel from an end of the second retaining portion  42 . A U-shaped configuration is formed between the second contacting portion  41  and the second retaining portion  42 . A protrusion  431  is formed on a junction connecting the second retaining portion  42  and the connection portion  43  and provided for engaging with the rib  114  of the first housing  10  to secure the first and second connectors  10 ,  30  together. 
   Each of second metal ear  50  is formed a metal sheet by stamping and comprises a solder  51 , an U-shaped portion  52  engaged onto the second transverse wall  31   b  from the cutout  311  to the notch  312 , and a pair of mounting portions  53  extending from two lateral ends of the U-shaped portion  52  and received in the cutout  311 . The U-shaped portion  52  defines a first wall  521 , a second wall  523  and a connecting wall  522  connecting the first and second walls  521 ,  523 . A projection  54  is extended outwardly from a middle portion of the first wall  521 , and a gap  55  is formed a bottom end of the second wall  523 . 
   When in assembly of the second connector  200 , the second terminal  40  is interfrentially fixed into the corresponding groove  35 , the second contacting portion  41 , the second retaining portion  42  and the connection portion  43  cooperative formed an U-shaped configuration received in the groove  35  and engaged with the second longitudinal peripheral wall  31   a  to make the second tail  44  extending outward of the longitudinal peripheral wall  31   a . At the same time, a space is formed between the protrusion  431  of the second terminal  40  and an inner face of the groove  35 . 
   Referring to  FIGS. 5-7 , when the first connector  100  is fully mated with the second connector  200  to electrically interconnect each other, the second peripheral wall  31  of the second connector  200  is received in the engagement passage  14 , and the trapeziform portion  342  of the flange  34  defined in the second connector  200  is received in the corresponding trapeziform recess  131  of the main body  13  defined in the first connector  100  to make the main body  13  received in the receiving cavity  33 . Simultaneously, the connection portion  43  of the second terminal  40  pressly engages with the contacting point  231  of the first terminal  20  at first and engages with the first contacting portion  23  of the first terminal  20  during the second connector  200  ulteriorly engaging with the first connector  100  to make the first contacting portion  23  distortion toward to the main body  13 . Thus the contacting point  231  electrically engages with the second contacting portion  41  and reliably conductivity of the first and second connectors  100 ,  200  is obtained. Furthermore, the protrusion  431  of the second terminal  40  fixedly wedges with the rib  114  of the first housing  10 , while the projection  54  of the second metal ear  50  fixedly mounts with the locking portion  116  of the slot  115  of the first housing  10 . With these configuration, the first and second connectors  100 ,  200  can reliably engagement with each other. 
   However, the disclosure is illustrative only, changes may be made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention.