Abstract:
An electrical connector includes an insulative housing and a number of first and second contacts retained therein. The insulative housing defines a first receiving cavity with a first tongue extending thereinto and a second receiving cavity with a second tongue extending thereinto. The second receiving cavity communicates with the first receiving cavity in an up to down direction. The first contacts are disposed on opposite first and second surfaces of the first tongue. Each first contact has a first contact portion protruding into the first receiving cavity and a first tail portion. The second contacts are disposed on a mounting surface of the second tongue. Each second contact has a flat second contact portion exposed to the second receiving cavity and a second tail portion. All first tail portions and second tail portions extend out of the insulative housing and are arranged in a row.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical connectors, more particularly to electrical connectors with improved contact arrangement. 
     2. Description of Related Art 
     USB 3.0 proposal was standardized by the USB Implementers Forum (USB-IF) at the end of 2008. An USB 3.0 B type connector includes an insulative housing and USB 2.0 contacts and extension contacts retained therein. Each contact has a contact portion to mate with a mating connector and a vertical tail portion extending out of the insulative housing for connecting with a circuit board. The insulative housing has two parallel tongue portions to retain the contact portions of USB 2.0 contacts and extension contacts respectively. The tail portions of all USB 2.0 contacts are arranged in two rows along an insertion direction of the mating connector, and the tail portions of all extension contacts are arranged in a row behind the tail portions of the USB 2.0 contacts. Therefore, the tail portions of the USB 3.0 B type connector are arranged in three rows along the insertion direction. As a result, the tail portions occupy a larger area of the circuit board which is inconvenient to rout wires. 
     Hence, an improved electrical connector is desired to overcome the above problems. 
     BRIEF SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, an electrical connector comprises: an insulative housing defining a first receiving cavity with a first tongue extending thereinto and a second receiving cavity with a second tongue extending thereinto, the second receiving cavity communicating with the first receiving cavity in an up to down direction and being essentially narrower than the first receiving cavity, the first tongue being parallel to the second tongue; a plurality of first contacts disposed on opposite first and second surfaces of the first tongue, each first contact having a flexible first contact portion cantileveredly protruding into the first receiving cavity and a first tail portion extending out of the insulative housing; and a plurality of second contacts disposed on a mounting surface of the second tongue, each second contact having a flat second contact portion exposed to the second receiving cavity and a second tail portion extending out of the insulative housing; wherein all first tail portions and second tail portions are arranged in a row. 
     According to another aspect of the present invention, an electrical connector comprises: an insulative housing defining a first receiving cavity with a first tongue extending thereinto and a second receiving cavity with a second tongue extending thereinto, the second receiving cavity communicating with the first receiving cavity in an up to down direction and being essentially narrower than the first receiving cavity, the first tongue being parallel to the second tongue; a plurality contacts having a plurality of first contacts disposed on opposite first and second surfaces of the first tongue and a plurality of second contacts disposed on a mounting surface of the second tongue, each first contact having a flexible first contact portion cantileveredly protruding into the first receiving cavity and a first tail portion extending out of the insulative housing; and each second contact having a flat second contact portion exposed to the second receiving cavity and a second tail portion extending out of the insulative housing; wherein the first and second contacts have a plurality of pairs of differential signal contacts and a plurality of grounding contacts, all first tail portions and second tail portions are arranged in a row along a transverse direction of the insulative housing, and there are at least a tail portion of the grounding contact located between the tail portions of adjacent two pairs of differential signal contacts. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an electrical connector with a circuit board according to the present invention; 
         FIG. 2  is a view similar to  FIG. 1 , while taken from a different aspect; 
         FIG. 3  is an exploded view of the electrical connector shown in  FIG. 1 ; 
         FIG. 4  is a view similar to  FIG. 3 , while taken from a different aspect; 
         FIG. 5  is a perspective view of a plurality of contacts of the electrical connector shown in  FIG. 1 ; and 
         FIG. 6  is a view similar to  FIG. 5 , while taken from a different aspect. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known circuits have been shown in block diagram form in order not to obscure the present invention in unnecessary detail. For the most part, details concerning timing considerations and the like have been omitted inasmuch as such details are not necessary to obtain a complete understanding of the present invention and are within the skills of persons of ordinary skill in the relevant art. 
     Reference will be made to the drawing figures to describe the present invention in detail, wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by same or similar reference numeral through the several views and same or similar terminology. 
     Referring to  FIGS. 1-5 , an electrical connector  100  for soldering to a circuit board  200  according to a first embodiment in the present invention is an USB 3.0 B type receptacle connector which can mate with a standard USB 3.0 B type plug (not shown) or a standard USB 2.0 B type plug (not shown). The electrical connector  100  comprises an insulative housing  1 , a plurality of contacts  2  attached to the insulative housing  1  and a metal shell  3  covering the insulative housing  1 . 
     The insulative housing  1  comprises a first housing  11 , a second housing  12  and a spacer  13  assembled together. The first housing  11  defines a mating port  14  for receiving the USB 3.0 or USB 2.0 B type plug. The mating port  14  has a first receiving cavity  141  and a second receiving cavity  142  located upper the first receiving cavity  141 . The second receiving cavity  142  communicates with the first receiving cavity  141  in an up to down direction and is essentially narrower than the first receiving cavity  141 . The first housing  11  has a first base portion  15  and a first tongue  16  integrally extending into the first receiving cavity  141 . The first base portion  15  defines two pairs of passageways  150  extending therethrough along an insertion direction of the plug. The first tongue  16  has a pair of opposite first and second surface  161 ,  162  each of which defines a pair of slots  163  communicating with the passageways  150  respectively, and the first and second surface  161 ,  162  are upper and lower surfaces of the first tongue  16 . The second housing  12  has a second base portion  17  and a second tongue  18  integrally extending into the second receiving cavity  142 . The first tongue  16  is much thicker than the second tongue  18 . The first base portion  15  defines a pair of grooves  152  extending forwardly from a rear and upper end thereof to retain the second housing  12 . The second base portion  17  has a pair of ribs  171  extending outwardly from two sides thereof to engage with the grooves  152  for positioning the second housing  12  to the first housing  11 . The second tongue  18  is parallel to the first tongue  16  and located upper the second tongue  18 . The second tongue  18  has a mounting surface  182  opposed to the first surface  161 . 
     The contacts  2  comprise a plurality of first contacts  21  disposed on the first and second surfaces  161 ,  162  of the first tongue  16  and a plurality of second contacts  22  disposed on the mounting surface  182  of the second tongue  18 . The first contacts  21  are same to contacts of standard USB 2.0 B type receptacle (not shown) and can mate with the standard USB 2.0 B type plug. All first and second contacts  21 ,  21  consist of contacts of USB 3.0 B type receptacle to mate with the standard USB 3.0 B type plug. 
     The first contacts  21  comprise a power contact  210 , a pair of first differential signal contacts  211  and a first grounding contact  212 . Each first contact  21  has a first retaining portion  214  retained in the passageways  150  of the first housing  11 , a flexible first contact portion  215  extending forwardly from a front end of the first retaining portion  214 , a first connecting portion  216  extending downwardly from a rear end of the first retaining portion  214 , and a first tail portion  217  extending backwardly and horizontally from a lower end of the first connecting portion  216 . The first contact portions  215  are cantileveredly received in the slots  163  of the first tongue  16  and protrude into the first receiving cavity  141 . 
     The first contact portions  215  of the power contact  210  and one of the pair of first differential signal contact  211  are disposed on the first surface  161 , and the first contact portions  215  of the first grounding contact  212  and one of the first differential signal contacts  211  are disposed on the second surface  162 . The first contact portions  215  of the pair of first differential signal contacts  211  are aligned with each other along the up to down direction. The first contact portions  215  of the power contacts  210  and the first grounding contact  212  are aligned with each other along the up to down direction. Therefore, an arrangement of the first contact portions  215  is same to that of the contacts of standard USB 2.0 B type receptacle. 
     The first tail portions  217  of the power contact  210  and one of the differential signal contacts  211  disposed on the first surface  161  are located at two sides of the first tail portions  217  of the grounding contact  212  and another differential signal contact  211 . Therefore, the first contacts  21  are arranged one after another along a transverse direction of the insulative housing  1  in the first tail portions  217  are the power contacts  210 , the first grounding contact  212  and the pair of differential signal contacts  211 . 
     The second contacts  22  are insert molded in the second housing  12  and the spacer  13  and comprise two pairs of differential signal contacts  221 ,  222  and a grounding contact  223  between the two pairs of differential signal contacts  221 . Each differential signal contact  221  has a second retaining portion  224  insert molded in the second housing  12 , a second contact portion  225  extending forwardly from the second retaining portion  224 , a second connecting portion  226  extending downwardly from a rear end of the second retaining portion  224 , and a second tail portion  228  extending backwardly and horizontally from a lower end of the second connecting portion  226 . The second grounding contact  223  has a second retaining portion  224  insert molded in the second housing  12 , a second contact portion  225  extending forwardly from the second retaining portion  224 , a pair of second connecting portions  226  extending downwardly from a rear end of the second retaining portion  224 , and a pair of second tail portions  227  extending backwardly and horizontally from a lower end of the second connecting portion  226 . The second retaining portion  224  of the second grounding contact  223  is wider than the other first and second retaining portions  214 ,  224  to assure a good grounding purpose. The second retaining portion  224  defines a hollow  2241  at a middle position thereof to prevent the connecting portion  226  from rebounding. The second connecting portions  226  of the second grounding contact  223  extend downwardly from two lower sides of the second retaining portion  224  thereof and spaced from each other along the transverse direction. 
     The second contact portions  225  of all second contacts  22  are disposed on the mounting surface  182  of the second tongue  18 . An arrangement of the first and second contact portions  215 ,  225  disposed on the first and second tongues  16 ,  18  respectively is same to that of the standard USB 3.0 B type receptacle. The second housing  12  is insert molded around all second contact portions  225  and second retaining portions  224 . The spacer  13  is insert molded around all second connecting portions  226 . Therefore, the assemble process of the second contacts  22  can be reduced. 
     All first tail portions  217  are located between the second tail portions  227  of the second grounding contact  223  along the transverse direction, thereby the second tail portions  227  are located at two sides of all first tail portions  217  along the transverse direction. The spacer  13  defines a recession  131  recessed from a front side thereof and between two second connecting portions  224  of the second grounding contact  223  to receive all first connecting portions  216  in order to assure all first connecting portions  216  and all second connecting portions  226  located at a common vertical plane, and the second connecting portions  224  are located at two sides of all first connecting portions  216 . Therefore, all connecting portions  216 ,  226  or all tail portions  217 ,  227 ,  228  are arranged one after other along the transverse direction as following: the pair of second differential signal contacts  221 , the second grounding contact  223 , the power contact  210 , the first grounding contact  212 , the pair of first differential signal contacts  211 , the second grounding contact  223  and the pair of second differential signal contacts  222 . 
     It is to see that there are two grounding contacts  223 ,  212  located between adjacent second and first differential signal contacts  221 ,  211  in the connecting portion  216  or the tail portion  217 ,  227 ,  228 , which can reduce cross talk between the adjacent differential signal contacts  221 ,  211  and improve the signal transmission thereof. Besides, all tail portions  217 ,  227 ,  228  are bended backwardly and horizontally from the lower end of all connecting portions  216 ,  226  at the same time to make all tail portions  217 ,  227 ,  228  arranged in a row along the transverse direction. Therefore, the electrical connector  100  of the present invention can be surface mounted to the circuit board  200  and the circuit board  200  need not set a plurality of through holes to position the tail portions  217 ,  227 ,  228 , which can strengthen the strength of the circuit board  200 . Besides, all tail portions  217 ,  227 ,  228  are arranged in a row which can be convenient to rout wires and occupy a small area of the circuit board  200 . 
     The metal shell  3  covers the insulative housing  1  to form said mating port  14  with the tongues  16 ,  18 . The metal shell  3  has a top wall  31 , a pair of side walls  32  bending downwardly from two sides of the top wall  31 , a mating wall  33  partially covering a front side of the mating port  14  and a rear wall  34  covering a rear side of the insulative housing  1 . Each side wall  33  has a mounting leg  320  extending downwardly from a lower end thereof to mount the electrical connector  100  to the circuit board  200 . The mating wall  33  bending downwardly from a front end of the top wall  31  and has a pair of flanges to lock with two side walls  32 . The mating wall  33  defines an opening  330  corresponding to the mating port  14 . 
     Referring to  FIG. 6 , an electrical connector  100  according to a second embodiment of the present invention is disclosed. The electrical connectors in the first and second embodiments are approximately similar to each other, and the difference is that: the first connecting portions  216 ′ or tail portions  217 ′ of the power contact  230 ′ and one of the first differential signal contacts  231 ′ disposed on the first surface  161  of the first tongue  16  are located between that of the first grounding contact  232 ′ and another first differential signal contact  231 ′. Therefore, all connecting portions  216 ′,  226 ′ or all tail portions  217 ′,  227 ′,  228 ′ are arranged one after other along the transverse direction as following: the pair of second differential signal contacts  221 ′, the second grounding contact  223 ′, the first grounding contact  212 ′, the power contact  210 ′, the pair of first differential signal contacts  211 ′, the second grounding contact  223 ′ and the pair of second differential signal contacts  222 ′. It is to see that there are two grounding contacts  223 ′,  212 ′ located between adjacent second and first differential signal contacts  221 ′,  211 ′ in the connecting portion  216 ′ or the tail portion  217 ′,  227 ′,  228 ′, which can reduce cross talk between the adjacent differential signal contacts  221 ′,  211 ′ and improve the signal transmission thereof. 
     Of course, the electrical connector  100  in an alternative embodiment of the present invention can be designed as following: the second grounding contact can be designed to has only one second tail portion; all tail portions of the first contacts and the second contacts are arranged in a row along the transverse direction also; and the first tail portion of the first grounding contact and the second tail portion of the second grounding contact are arranged at two sides of the first tail portions of the two first differential signal contacts along the transverse direction, which can assure that there are at least a tail portion of the grounding contact located between the tail portions of adjacent two pairs of differential signal contacts along the transverse direction. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.