Abstract:
An electrical connector ( 200 ) includes an insulative housing ( 50 ) defining a number of passageways ( 56 ) and a number of conductive terminals ( 60 ) residing in corresponding passageways ( 56 ), respectively. The conductive terminals ( 60 ) each include a securing portion ( 62 ) extending along a lengthwise direction of the passageways ( 56 ), a connecting portion ( 64 ) extending upwardly from the securing portion ( 62 ), a transitional portion ( 65 ) extending form the other end of the securing portion ( 62 ) towards the printed circuit board ( 70 ), a solder portion ( 64 ) formed on a distal end of the transitional portion ( 65 ). The securing portion ( 62 ) defines a wider securing surface ( 622 ). A partial projection of the transitional portion ( 65 ) projected on a plane defined by the securing surface ( 622 ) is separated an angle with a direction of the terminals ( 60 ) being inserted.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to the field of electrical connectors. And more particularly, one embodiment of the present invention relates to an electrical connector embedded with conductive terminals for connecting a chip module to a printed circuit board. 
     2. General Background 
     Electrical connectors are widely used in various computer systems for forming electrical connection between two separate electrical interfaces, such as an electronic component and a printed circuit board. Referring to  FIGS. 1-3 , an electrical connector  100  basically includes an insulative housing  20  defining a number of passageways  22  and a number of conductive terminals  30  residing in corresponding passageways  22 , respectively. The conductive terminal  30  includes a vertical securing section  32  received in the passageway  22  of the housing  20 , a connecting portion  36  extending from the securing portion  32 , a tail portion  34  extending from a lower end of the securing portion  32 , and a transitional portion  35  formed between the tail portion  34  and the securing portion  32 . The securing portion  32  defines a securing surface  322  and the transitional portion  35  is bent in a direction vertical to the securing surface  322 . The transitional portion  35  can provide the terminal  30  with an elastic flexibility in a direction vertical to the printed circuit board, thereby preventing the terminal  30  from breaking due to lack of the elastic flexibility required in the vertical direction to the printed circuit board. 
     However, with the development of the chip module  40  forward high density and minimized size, the arrangement of terminals  30  received in the electrical connector is more and more compact. While the terminals bear greater and more complicate force, terminals with minimized size and greater flexibility are more and more needed. In the electrical connector described in above paragraph, a centerline that the transitional portion projects on a plane defined by the securing surface is M and the direction of the terminals inserted into the housing is Y. the centerline M is parallel to the Y direction. That is to say, the transitional portion of the terminal only provides a single directional flexibility vertical to the printed circuit board, which can not meet the need of multi-directional flexibility of the terminals. 
     Therefore, there is a heretofore unaddressed need in the industry to address the aforementioned deficiencies and inadequacies. 
     SUMMARY 
     According to an embodiment of the present invention, an electrical connector includes an insulative housing defining a number of passageways and a number of conductive terminals residing in corresponding passageways, respectively. The conductive terminals each include a securing portion extending along a lengthwise direction of the passageways, a contacting portion extending upwardly from the securing portion, a transitional portion extending form the other end of the securing portion towards the printed circuit board, a solder portion formed on a distal end of the transitional portion. The securing portion defines a wider securing surface. Wherein a partial projection of the transitional portion projected on a plane defined by the securing surface is angled with respect to an insertion direction of the terminal into the housing. 
     In relative to the conventional technology, the electrical connector defines a slant transitional portion, hence improving a flaw that the terminals can only provide flexibility in one direction. Furthermore, the resistance capability and the durability of the terminals are attained, and the electrical and mechanical connection can be assured. 
     The present invention is illustrated by way of example and not limitation in the figures of the appended drawings, in which like references indicate identical elements, and in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts an exemplary cross-sectional view of a conventional electrical connector, wherein the terminals received in the electrical connector do not contact with a chip module; 
         FIG. 2  depicts an exemplary isometric view of a conductive terminal shown in  FIG. 1 ; 
         FIG. 3  depicts an exemplary projected view of the terminal shown in  FIG. 1 ; 
         FIG. 4  depicts an exemplary cross-sectional view of an electrical connector of the first embodiment in accordance with the invention, wherein the terminals received in the electrical connector do not contact with a chip module; 
         FIG. 5  depicts an exemplary isometric view of a conductive terminal shown in  FIG. 4 . 
         FIG. 6  depicts an exemplary isometric view of the conductive terminal shown in  FIG. 5 , in another perspective. 
         FIG. 7  depicts an exemplary cross-sectional view of an electrical connector of the second embodiment in accordance with the invention, wherein the terminals received in the electrical connector do not contact with a chip module; 
         FIG. 8  depicts an exemplary projected view of a terminal received in the electrical connector shown in  FIG. 7 , projected on a plane defined by the securing surface. 
         FIG. 9  depicts an exemplary cross-sectional view of an electrical connector of the third embodiment in accordance with the invention, wherein the terminals received in the electrical connector do not contact with a chip module; 
         FIG. 10  depicts an exemplary projected view of a terminal shown in  FIG. 9 , projected on the plane defined by the securing surface. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In the following description, for purpose of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the embodiments of the present invention. 
     The following description includes terms such as upper, lower, upwardly and the like, that are used for descriptive purpose only and are not to be construed as limiting. That is, these terms are terms that are relative only to a point of reference and are not meant to be interpreted as limitation but are instead, included in the following description to facilitate understanding of the various aspects of the present invention. 
     Referring to  FIGS. 4-6 , an electrical connector  200  for connecting a chip module  70  to a printed circuit  90  in accordance with a first embodiment of the present invention includes an insulative housing  50  defining a number of passageways  56  therein and a number of conductive terminals  60  residing in the corresponding passageways  56 , respectively. 
     Individual elements of the electrical connector  200  will now be described in greater detail. The housing  50  includes a supporting surface  52  to accept the chip module  70  thereon and an opposite mounting surface  54  facing to a printed circuit board  70 . A number of passageways  56  extending between the supporting surface  52  and the mounting surface  54  are arranged in the housing  50  in a predetermined matrix fashion. The passageway  56  defines a rectangular receiving channel  562  and an elongate securing channel  564  commutated with the receiving channel  562 . 
     As shown in  FIG. 5  and  FIG. 6 , a number of conductive terminals  60  made by stamping and bending are received in corresponding passageways  56 , respectively. Each conductive terminal  60  includes a vertical oriented securing section  62  having a number of interfering blocks  620  at two lateral sides thereof for inferentially contacting with inner walls of the securing channel  564 , a connecting section  66  extending upwardly from the securing portion  62 , and a tail portion  64  extending downwardly from an end of the securing portion  62 , for instance a soldering pad, to be mounted on a printed circuit board  90 . The securing portion  62  defines a securing surface  622 . A curved transitional portion  65  is defined between the tail portion  64  and the securing portion  62 . A centerline of the projection that the transitional portion  65  projects on a plane defined by the securing surface  622  is a line b. The direction of the terminals inserted into the housing is direction Z. The centerline b is angular with Z a separation angle β. Furthermore, the width of the different position of the transitional portion can be altered in accordance with resistance capability of the terminals needed. 
     The connecting portion  66  comprises an engaging portion  660  extending vertically from the securing portion  62 , and a retention portion  662  extending from a lateral side thereof, and a cantilever  664  extending arcuately and upwardly from a top end of the retention portion  662 . The cantilever  664  defines a contact portion  666  on a top end thereof for contacting with a pad attached to the chip module  70 . 
     In assembly, the terminals  60  are inserted into passageways  56  of the housing  50  from a top side of the housing. The securing portion  62  abuts against sidewalls of passageways  56  so that the interfering blocks  620  of the securing portion  62  engage interferentially with inner surfaces of the securing channel  564 , thereby the terminals  60  securing in the passageways  56 . The cantilever  664  of the terminal  60  extends beyond the supporting surface  52  of the housing  50  so the top surface of the contact portion  666  abuts against the pad attached on the chip module  70 . The tail portion  64  extends beyond the mounting surface  54  of the housing  50  for inserting into the printed circuit board  90  and being soldered thereon. The centerline of the transitional portion  65  projected on a plane defined by the securing surface  622  is a. The direction of the terminals  60  inserted into the housing  50  is Z. The centerline a is separated an angle β with the direction Z, so the transitional portion  65  not only provides a flexibility vertical to the contacting surface between the chip module  70  and the housing  50  but also a flexibility obliquely to this direction thereby improving the drawback of terminals  60  that only provide one direction flexibility and enhancing the stability of the electrical connector  200 . 
     Referring to  FIGS. 7-8 , an electrical connector  200 ′ of the second embodiment in accordance with the invention comprises a housing  50 ′ and a plurality of terminals  60  received in the housing  50 ′. 
     In this embodiment, the terminal  60 ′ comprises a securing portion  62 ′, a connecting portion  66 ′ extending form the securing portion  62 ′ and a tail portion  64  extending form a lower end of the securing portion  62 ′, and a transitional portion  65 ′ formed between the tail portion  64 ′ and the securing portion  62 ′. The securing portion  62 ′ defines a securing surface  622 ′ and the transitional portion  65 ′ is disposed as two parts comprising a first twist portion  651 ′ and a second twist portion  652 ′. The centerlines of the first twist portion  651 ′ and the second twist portion  652 ′ projected on the plane of the securing surface defined by are lines c′, d′. The inserting direction of the terminals inserted into the housing is direction Z′. The lines c′, d′ are separated angles α′, β′ with Z′. So the first twist portion  651 ′ and the second twist portion  652 ′ can improve the flexibility of the terminals  60 ′ and enhance the stability of the electrical and mechanical connection between the terminals  60 ′ and the printed circuit board  70 ′. 
     As illustrated in  FIG. 9  to  FIG. 10 , an electrical connector  200 ″ of a third embodiment in accordance with the invention comprises a housing  50 ″ and a plurality of terminals  60 ″ received in. 
     In this embodiment, the terminal  60 ″ comprises a securing portion  62 ″, a connecting portion  66 ″ extending form the securing portion  62 ″ and a tail portion  64 ″ extending form a lower end of the securing portion  62 ″, and a transitional portion  65 ″ formed between the tail portion  64 ″ and the securing portion  62 ″. The securing portion  62 ″ defines a securing surface  622 ″ and the transitional portion  65 ″ is disposed as three parts comprising a vertical buffering portion  651 ″, a horizontal buffering portion  653 ″ and a twist portion  652 ″ disposed between the vertical buffering portion  651 ″ and the horizontal buffering portion  653 ″. The centerlines of the vertical buffering portion  651 ″ and the horizontal buffering portion  653 ″ projected on a plane defined by the securing surface  622 ″ are two lines e″, f″, which are parallel to the direction of the terminals being inserted into the housing. The centerline of the twist portion  652 ″ projected on the plane defined by the securing surface is line g″, which is separated an angle α″ with the direction of the terminals  60 ″ being inserted into the housing  50 ″. The vertical buffering portion  651 ″ and the horizontal portion  652 ″ can ease the deformation of the transitional portion  653 ″ due to stress concentration and the twist portion  653 ″ can improve the problem of the one direction flexibility. 
     In connection with the preceding description, the electrical connectors in accordance with embodiments of the present invention can create multi-directional flexibility effect, which possibly optimize electrical and mechanical connection between terminals and the printed circuit board during signal transmission. 
     While the present invention has been illustrated by description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications in the spirit and scope of the present invention will readily appear to one skilled in the art. Therefore, the present invention is not limited to the specific details and illustrative examples shown and described.