Patent Publication Number: US-11381013-B2

Title: Electrical connector

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an electrical connector, and particularly to the electrical connector equipped with a plurality of contacts each having a primary part and a secondary part mutually discrete from while mechanically and electrically connected to each other wherein the primary part and the secondary part have optionally different conductivities and thicknesses from each other. 
     2. Description of Related Arts 
     Taiwan Patent No. TWM578031 discloses an electrical connector for use between a CPU (Central Processing Unit) ad a PCB (Printed Circuit Board). On one hand, the number of the contacts gets more and more so as to increase the mating normal force, i.e., the total reaction forces of all the contacts against the CPU. To avoid the undesired increased mating force, it tends to lower the reaction force of each contact by lessening the width and/or the thickness of each contact. On the other hand, the delivery power of the whole connector will be increased to meet the high speed transmission. To comply with the high power, it tends to increase the thickness and width of each contact for transmission consideration. Notably, such a conflict situation can not be solved by the current contact design. 
     It is desired to provide an electrical connector having the large number of the contacts for high power transmission while avoiding the undesired large reaction normal force during mating. 
     SUMMARY OF THE INVENTION 
     To achieve the above object, an electrical connector for connecting a CPU to a printed circuit board. The connector includes an insulative housing having opposite upper and lower surfaces with a plurality of passageways extending therethrough, and a plurality of contacts retained in the corresponding passageways, respectively. Each contact includes a primary part and a secondary part discrete from each other. The primary part includes a first main body with a first spring arm extend upwardly through the upper surface for mating with the CPU, and a first soldering section around the lower surface. The secondary part includes a second main body with a second spring arm contacting the first main body, and a second soldering section around the lower surface. A solder ball is attached to the first soldering section and/or the second soldering section. 
     Other advantages and novel features of the 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 DRAWING 
         FIG. 1  is a perspective view of an electrical connector according to a preferred embodiment of the invention; 
         FIG. 2  is a perspective view of the electrical connector of  FIG. 1  wherein the solder ball is removed away from the corresponding soldering sections; 
         FIG. 3  is another perspective view of the electrical connector of  FIG. 2 ; 
         FIG. 4  is an exploded perspective view of the electrical connector of  FIG. 2 ; 
         FIG. 5  is another exploded perspective view of the electrical connector of  FIG. 4 ; 
         FIG. 6  is a perspective view of the contact of the electrical connector of  FIG. 4 ; and 
         FIG. 7  is a cross-sectional view of the electrical connector of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in  FIGS. 1-7 , an electrical connector  100  for connection between a CPU  900  and a PCB  910 , includes an insulative housing  1  forming a plurality of passageways  10  (only one shown) extending through both opposite upper surface  11  and lower surface  12  of the housing  1  in the vertical direction Z. A plurality of contacts  2  (only one shown) are retained in the corresponding passageways  10 , respectively. At least one contact  2  includes a primary/mating part  21  and a secondary/soldering part  22  mutually discrete from each other while commonly received with the same corresponding passageway  10  and electrically and mechanically connected to each other. In this embodiment, the secondary part  22  has a higher conductivity than the primary part  21 , and the secondary part  22  is thicker than the primary part  21 . The primary part  21  includes a first main body  211 , a first spring arm  212  extending from an upper portion of the first main body  211  and above the upper surface  11  with the corresponding contacting section  2121  for contacting the CPU  900 , and a first soldering/mounting leg  213  extending from a lower portion of the first main body  211  around the lower surface  12 . 
     The secondary part  22  includes a second main body  221 , a second spring arm  222  extending from an upper portion of the second main body  221  toward to contact the first main body  211 , and a second soldering/mounting leg  223  extending from a lower portion of the second main body  221  around the lower surface  12 . In this embodiment, the first main body  211  and the second main body  221  are spaced from each other in the first horizontal direction X perpendicular to the vertical direction Z while the first soldering leg  213  and the second soldering leg  223  are closely disposed with each other in a second horizontal direction Y perpendicular to both the vertical direction Z and the first horizontal direction X. Understandably, the first spring arm  212  and the second spring arm  222  are partially overlapped with each other in the vertical direction. In detail, the first soldering leg  213  forms a first soldering section  2130 , the second soldering section  223  forms a second soldering section  2230 , and the first soldering section  2130  and the second soldering section  2230  are coplanar with each other for commonly forming a soldering section/platform on which the solder ball  3  is attached. 
     To enhance assembling between the primary part  21  and the secondary part  22 , the second spring arm  222  is soldered/welded to the first main body  211 . The first spring arm  212  includes a bending section  2122  and an oblique section  2123  linked between the bending section  2122  and the contacting section  2121 . The second spring arm  222  includes an oblique section  2221  and an abutting section  2222  abutting against the first main body  211 . 
     The primary part  21  is stamped and formed by first sheet metal (not shown) and originally linked to a contact carrier (removed/not shown) via the first connection section  214 . Similarly, the secondary part  22  is stamped and formed by second sheet metal (not shown) and originally to a contact carrier (removed/not shown) via the second connecting section  224 . In a top view, the passageway  10  forms a Z-shaped configuration with the first connecting section  214  and the second connecting section  224  are located at two opposite ends of the Z-shaped configuration while the first spring arm  212  and the second spring arm  222  are located at a middle region of the Z-shaped configuration. 
     In this embodiment, the contacting section  2121  may keep the desired resiliency with relatively less width and thickness thereof as used in the conventional design. Different from the conventional design, the invention uses the secondary part  22  to form an additional transmission path between the contacting section  2121  which contacts the CPU  900 , and the solder ball  3  which contacts the PCB  910 . The secondary part  22  may use material with higher conductivity and thicker/wider configuration, compared with the primary part  21  for not only high power transmission but also reinforcement of the whole contact  2  in the passageway  10 . Alternately, the first soldering leg  213  and the second soldering leg  223  may be connected to each other either vertically or sidewardly, and only one of the first soldering leg and the second soldering leg is attached with the solder ball. In brief, in the invention a first transmission path is formed between the solder ball  3  and the contacting section  2121  via the primary part  21 , and a second transmission path therebetween mainly via the secondary part  22  which has higher conductivity and/or lower resistance than the primary part  21  electrically. 
     Although the present invention has been described with reference to particular embodiments, it is not to be construed as being limited thereto. Various alterations and modifications can be made to the embodiments without in any way departing from the scope or spirit of the present invention as defined in the appended claims.