Patent Publication Number: US-8118603-B2

Title: Electrical connector

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electrical connector. In particular, the present invention relates to an electrical connector with pins that can prevent the short-circuit problem from occurring. 
     2. Description of Related Art 
     Reference is made to  FIGS. 1 and 2 . The electrical connector of the prior art includes an insulating main body (a) and a plurality of conducting pins (b). The insulating main body (a) has a plurality of receiving holes (a 1 ) that are disposed in the lengthwise direction and the lateral direction. The conducting pins (b) are respectively installed in the receiving holes (a 1 ). Each of the conducting pins (b) has a base portion (b 1 ). The base portion (b 1 ) is located in the receiving hole (a 1 ). A flexible arm (b 2 ) extends upwards from the base portion (b 1 ). A welding portion (not shown in the figure) extends downwards from the base portion (b 1 ). The flexible arm (b 2 ) further includes a bending portion (b 21 ) that extends and bends upwards from one end of the base portion (b 1 ) and part of the bending portion (b 21 ) extends outside of the receiving hole (a 1 ). A connection portion (b 22 ) slantedly bends and extends upwards from the bending portion (b 21 ). A contact portion (b 23 ) is located at the end of the connection portion (b 22 ). 
     The electrical connector is electrically connected with a chip (c) located above the electrical connector and a circuit board (not shown in the figure) located below the electrical connector. When the chip (c) is installed on the insulating main body (a), the chip (c) presses and contacts the contact portion (b 23 ) of the conducting pins (b). At this time, when the conducting pins (b) are located in the same lengthwise row and adjacent, the flexible arm (b 2 ) of one conducting pin (b) is located above the flexible arm (b 2 ) of another conducting pin (b), the contact portion (b 23 ) of one conducting pin (b) is located above the connection portion (b 22 ) of another conducting pin (b), and the bend portion (b 21 ) of another conducting pin (b) is located below the connection portion (b 22 ) of one conducting pin (b). By utilizing the conducting pin (b), the chip (c) and the circuit board perform the signal transmission well. 
     The drawbacks of the electric connector are: 
     1. When the chip is pressed to contact the conducting pins, the flexible arm of one conducting pin is located above the flexible arm of another conducting pin, the contact portion of one conducting pin is located above the connection portion of another conducting pin, the bend portion of another conducting pin is located below the connection portion of one conducting pin and there is no yield space or separating structure, the flexible arms of the conducting pins that are located in the same lengthwise row and adjacent easily contact to each other. The short circuit problem occurs. 
     2. The connection portion extends upwards from the bend portion directly. Comparing with a connection portion slants downwards a predetermined distance from the bend portion and then is curved and extended upwards, the conducting pin is easily bent when the chip is pressed to contact the contact portion of the conducting pin. 
     3. Because the connection portion extends upwards from the bend portion, the press distance of the flexible arm is larger. After the conducting pin is pressed many times, the conducting pin is easily fatigued. The contact between the chip and the contact portion will be instable. 
     SUMMARY OF THE INVENTION 
     One particular aspect of the present invention is to provide an electrical connector that has a yield space for preventing the short circuit problem from occurring and solves the pin-bend problem and the fatigued problem. 
     The electrical connector is used for connecting a chip. The electrical connector includes an insulting main body, and a plurality of pins. The insulting main body has a plurality of receiving holes, and the receiving holes are disposed in the insulting main body in at least one row. The pins are located in the receiving holes. Each pin has a base portion located in the receiving hole, a welding portion extends downwards from the base portion, a flexible arm having a first bend portion that bends and extends upwards from the base portion, a second bend portion that bends from the first bend portion, part of the second bend portion extends out of the receiving hole and above the second bend portion, there is a first yield space, a third bend portion that slantedly bends and extends upwards from the second bend portion and below the third bend portion, there is a second yield space, a contact portion located at the end of the flexible arm and corresponding to the chip. When the chip is pressed to contact the contact portion of the pins, the flexible arm of one pin is located above the flexible arm of another pin, the contact portion of one pin is located above the first yield space of another pin, and the first bend portion of another pin is located below the second yield space of one pin for the two pins that are located in the same lengthwise row and adjacent. 
     For the two pins that are located in the same lengthwise row and adjacent, the flexible arm of one pin is located above the flexible arm of another pin, the contact portion of one pin is located above the first yield space of another pin, and the first bend portion of another pin is located below the second yield space of one pin. When the chip is pressed to contact the contact portion, the contact portion of one pin is located in the first yield space of another pin and the first bend portion of another pin is located in the second yield space of one pin so that the flexible arms of the two pins will not contact each other. The short circuit problem or the interference problem is avoided. 
     Furthermore, because the flexible arm has a second bend portion bent from the first bend portion, the third bend portion slantedly bends and extends upwards from the second bend portion, and the end of the flexible arm has the contact portion, the slope of the flexible arm is smaller than the slope of the first bend portion directly bending and extending to form the contact portion. Therefore, when the pin is pressed, the flexible arm will not be easily bent. The press distance of the pin is also reduced by this structure. When the pin is pressed many times, the flexible arm will not be easily fatigued. The usage life of the pin is improved. 
     For further understanding of the present invention, reference is made to the following detailed description illustrating the embodiments and examples of the present invention. The description is for illustrative purpose only and is not intended to limit the scope of the claim. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of part of the electrical connector of the prior art; 
         FIG. 2  is a schematic diagram of part of the electrical connector being pressed by a chip of the prior art; 
         FIG. 3  is an exploded perspective view of the receiving hole and the pin of the electrical connector of the present invention; 
         FIG. 4  is a side view of the pin of the electrical connector of the present invention; 
         FIG. 5  is an assembly perspective view of the electrical connector and the pin of the present invention; 
         FIG. 6  is a cross-sectional diagram of part of the receiving hole and the pin of the electrical connector be assembled of the present invention; 
         FIG. 7  is a cross-sectional diagram of  FIG. 5 ; and 
         FIG. 8  is a cross-sectional diagram of the pins being pressed by the chip of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference is made to  FIG. 3 . The electrical connector includes an insulating main body  1 , a plurality of pins  2  located in the insulating main body  1 , and a plurality of soldering balls  3  corresponding to the pins  2 . 
     Reference is made to  FIGS. 3 and 5 . The insulating main body  1  has an upper surface  11  and a lower surface  12 , and a plurality of receiving holes  13  that pass through the upper surface  11  and the lower surface  12  (in this embodiment, the receiving holes  13  are disposed in a plurality of rows in the lengthwise direction and the lateral direction. for other embodiments, the receiving holes  13  can be disposed in slant rows or other ways). Each receiving hole  13  has a front inner wall  131  and a rear inner wall  132 , and a left inner wall  133  and a right inner wall  134 . The front inner wall  131  that is close to the middle of the lower surface  12  protrudes to faun a first positioning portion  135 . The rear inner wall  132  that is close to the lower surface  12  has a second positioning portion  136 . The middle of the left inner wall  133  and the right inner wall  134  respectively have a third positioning portion  137  and a fourth positioning portion  138  that are lengthwise-shaped. 
     Reference is made to  FIGS. 3 and 4 . Each of the pins  2  has a base portion  21 , a holding portion  22 , a flexible arm  23 , a transition portion  24 , and a welding portion  25 . The base portion  21  is located in the receiving hole  13  and matches the fourth positioning portion  138 . The holding portion  22  extends from one side of the base portion  21  and matches the third positioning portion  137 . The base portion  21  and the holding portion  22  are located in the common plane. The flexible arm  23  bends and extends upwards and forwards from the base  21 , and part of the flexible arm  23  extends outside of the receiving hole  13 . The transition portion  24  bends and extends downwards from one side of the holding portion  22  that is close to the base portion  21 , and the transition portion  24  matches the first positioning portion  135 . The welding portion  25  extends downwards from the transition portion  24 . One side of the welding portion  25  that is close to the base portion  21  has a concave trough  251 , and another side of the welding portion  25  has an inversed book  252 . The inversed hook  252  matches the second positioning portion  136 . 
     The flexible arm  23  further has a first bend portion  231 , a second bend portion  232 , a third bend portion  233 , a connection portion  234 , and a contact portion  235 . The first bend portion  231  bends and extends upwards and backwards from the base portion  21 . The second bend portion  232  bends and extends forwards from the first bend portion  231 , above the second bend portion  232 , there is a first yield space (not labeled) and the second bend portion  232  has a first bend point (not labeled). The third bend portion  233  slantedly bends and extends upwards and forwards from the second bend portion  232 , below the third bend portion  233 , there is a second yield space (not labeled), and the third bend portion  233  has a second bend point (not labeled). The connection portion  234  extends forwards from the third bend portion  233 . The contact portion  235  is located at the end of the connection portion  234 , and has a third bend point (not labeled). The first bend point and the third bend point forms a dash line (not shown in the figure). The second bend point is located above the dash line. 
     Reference is made to  FIGS. 5-8 . The electrical connector is used for electrical conducting a chip  4  and a circuit board (not shown in the figure) so that the chip  4  is electrically conducted with the circuit board well. 
     Firstly, the pins  2  are respectively installed in the corresponding receiving holes  13  of the insulating main body  1  from top to bottom. The second positioning portion  136  is located above the inversed hook  252  for blocking the pin  2  to move upwards. The first positioning portion  135  is located below the transition portion  24  for blocking the pin  2  to move downwards. The base portion  21  is wedged between the fourth positioning portion  138  and the front inner wall  131  for limiting the movement of the pin  2  in the front and back directions. The holding portion  22  is wedged between the third positioning portion  137  and the front inner wall  131  for limiting the movement of the pin  2  in the front and back directions. Part of the flexible arm  23  extends outside of the upper surface  11  of the insulating main body  1 . 
     Next, the soldering balls  3  are installed into the corresponding receiving holes  13  from the bottom up. The soldering ball  3  is adjacent to the concave trough  251  of the welding portion  25 , and is close to the lower surface  12  of the insulating main body  1 . 
     The assembled electrical connector is welded onto the circuit board. By using the soldering balls  3 , the welding portion  25  is welded on the circuit board well. 
     Finally, the chip  4  is installed on the insulting main body  1  of the electrical connector. When the chip  4  is pressed to contact the contact portion  235  of the pin, the flexible arm  23  of the pin  2  located in the rear row is located above the flexible arm  23  of the pin  2  located in the front row, the contact portion  235  of the pin  2  located in the rear row is located in the first yield space of the pin  2  located in the front row, and the first bend portion  231  of the pin  2  located in the front row is located in the second yield space of the pin  2  located in the rear row for two pins  2  that are located in the same lengthwise row and adjacent. Thereby, the pins  2  can transmit signal well between the chip  4  and the circuit board. 
     The electrical connector of the present invention has the following advantages. 
     1. Part of the flexible arm of the pin located in the rear row is located above the flexible arm of the pin located in the front row for two pins that are located in the same lengthwise row and adjacent, above the second bend portion, there is a first yield space, and below the third bend portion, there is a second yield space. When the chip is pressed to contact the contact portion, the contact portion of the pin located in the rear row is located in the first yield space of the pin located in the front row, and the first bend portion of the pin located in the front row is located in the second yield space of the pin located in the rear row. Therefore, the flexible arm of the pin located in the front row will not easily contact the flexible arm of the pin located in the rear row. The short circuit problem and the interference problem are avoided. 
     2. Because the flexible arm has a second bend portion bent from the first bend portion, the third bend portion slantedly bends and extends upwards from the second bend portion, the connection portion extends forwards from the third bend portion, and the end of the connection portion has the contact portion, the slope of the flexible arm is smaller than the slope of the first bend portion being directly bent and extended to form the contact portion. Therefore, when the pin is pressed, the flexible arm will not be easily bent. The press distance of the pin is also reduced by this structure. When the pin is pressed many times, the flexible arm will not be easily fatigued. The usage life of the pin is improved. 
     3. The welding portion has a concave trough. When the electrical connector is welded onto the circuit board, the contact area of the soldering ball and the welding portion becomes larger and the concave trough is embedded into the interior of the soldering ball to achieve the stable effect. Thereby, the electrical connector is welded with the circuit board well. 
     The description above only illustrates specific embodiments and examples of the present invention. The present invention should therefore cover various modifications and variations made to the herein-described structure and operations of the present invention, provided they fall within the scope of the present invention as defined in the following appended claims.