Patent Publication Number: US-2009239396-A1

Title: Compression Connector

Description:
FIELD OF INVENTION 
     The present invention relates broadly to a compression connector, a terminal for a compression connector and an assembly comprising a compression connector and a PCB. 
     BACKGROUND 
     Typically, electrical connection between a Printed Circuit Board (PCB) and a compression connector is achieved by receiving portions of terminals of the connector in corresponding holes or openings in the PCB. The contact portions of the terminals are dimensioned to fit into the openings in the PCB for electrical connection with contact traces of the PCB. 
     However, there is a disadvantage of low manufacturing tolerances in both the openings in the PCB and the dimensioning of the contact portions to ensure electrical connection. Thus, it requires a stringent precision manufacturing process which will add to the complexity of the PCB and the connector fabrication. 
     In addition, there is an issue of unwanted disengagement between the PCB and the connector which can result in an open circuit. An additional member such as a clamp may be used to retain the connector to the PCB to prevent unwanted disengagement between the connector and the PCB. However, this will lead to an undesirable additional step in the assembly process and the usage of an additional member. 
     Therefore, there is a need to provide a compression connector designed to address at least one of the above-mentioned problems. 
     SUMMARY 
     In accordance with a first aspect of the present invention, there is provided a compression connector comprising: a housing; one or more terminals disposed in the housing; each terminal comprising a substantially U-shaped contact portion protruding above a surface level of the housing with a close end of the substantially U-shaped contact portion facing away from the housing, the substantially U shaped contact portion comprising a first leg connected to a main body of said each terminal and a second leg having a free end, the free end being disposed substantially at or below the surface level of the housing; wherein the first and second legs are angled with respect to each other in a quiescent state and such that the first and second legs are substantially parallel to each other in a contact state where the substantially U-shaped contact portion resiliently engages a contact through-hole of a PCB. 
     The substantially U-shaped contact portion may comprise a protrusion extending outwardly from the substantially U-shaped contact portion. 
     The protrusion may be disposed on the second leg of the substantially U-shaped contact portion. 
     The protrusion may be disposed on the second leg to achieve a force distribution within the PCB for preventing deformation of the terminal when the substantially U-shaped contact portion resiliently engages the though-hole. 
     The first leg of the substantially U-shaped contact portion may extend substantially perpendicularly from the housing, and the second leg of the substantially U-shaped contact portion may be angled with respect to the first leg. 
     The terminal may further comprise a solder tail portion extending beyond the housing. 
     The terminal further may comprise a curved portion between the substantially U-shaped contact portion and the solder tail portion for resiliently supporting the substantially U-shaped contact portion. 
     A plurality of terminals may be disposed in two rows along the housing. 
     The terminals may be arranged such that the orientation of the terminals is rotated by about 180° in one row with respect to the other row. 
     The terminals are arranged such that a substantially even force distribution is achieved when the substantially U-shaped contact portions resiliently engage the through-holes of the PCB. 
     In accordance with a second aspect of the present invention, there is provided a terminal for a compression connector, the terminal comprising: a substantially U-shaped contact portion for protruding above a surface level of a housing of the connector with a close end of the substantially U-shaped contact portion facing away from the housing, the substantially U shaped contact portion comprising a first leg connected to a main body of said each terminal and a second leg having a free end, the free end being disposed substantially at or below the surface level of the housing; wherein the first and second legs are angled with respect to each other in a quiescent state and such that the first and second legs are substantially parallel to each other in a contact state where the substantially U-shaped contact portion resiliently engages a contact through-hole of a PCB. 
     The substantially U-shaped contact portion may comprise a protrusion extending outwardly from the substantially U-shaped contact portion. 
     The protrusion may be disposed on the second leg of the substantially U-shaped contact portion. 
     The protrusion may be disposed on the second leg to achieve a force distribution within the PCB for preventing deformation of the terminal when the substantially U-shaped contact portion resiliently engages the though-hole. 
     The first leg of the substantially U-shaped contact portion may extend substantially perpendicularly from the housing, and the second leg of the substantially U-shaped contact portion may be angled with respect to the first leg. 
     The terminal may further comprise a solder tail portion extending beyond the housing. 
     The terminal may further comprise a curved portion between the substantially U-shaped contact portion and the solder tail portion for resiliently supporting the substantially U-shaped contact portion. 
     In accordance with a third aspect of the present invention, there is provided an assembly comprising: a compression connector; a PCB; wherein the compression connector comprises: a housing; one or more terminals disposed in the housing; each terminal comprising a substantially U-shaped contact portion protruding above a surface level of the housing with a close end of the substantially U-shaped contact portion facing away from the housing, the substantially U shaped contact portion comprising a first leg connected to a main body of said each terminal and a second leg having a free end, the free end being disposed substantially at or below the surface level of the housing; wherein the first and second legs are angled with respect to each other in a quiescent state and such that the first and second legs are substantially parallel to each other in a contact state where the substantially U-shaped contact portion resiliently engages a contact through-hole of a PCB. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       Embodiments of the invention will be better understood and readily apparent to one of ordinary skill in the art from the following written description, by way of example only, and in conjunction with the drawings, in which: 
         FIG. 1  shows a schematic diagram of a compression connector before assembly with a PCB, the PCB shown in cross-section. 
         FIG. 2  shows a schematic cross-sectional view of an assembly of the compression connector and the PCB in a mated condition. 
         FIG. 3  shows a schematic perspective cross-sectional view of the assembly of the compression connector and the PCB in the mated condition. 
     
    
    
     DETAILED DESCRIPTION  
       FIG. 1  shows a schematic view of a compression connector  102  before assembling with a PCB  104 , the PCB  104  shown in cross-section. The compression connector  102  comprises a housing  106  and one or more terminals  108  disposed in the housing  106 . 
     The housing  106  is made of high temperature engineering plastic. Other non-conductive materials such as, but not limited to, generic engineering plastics, e.g. Liquid Crystal Polymer (LCP), may be used for manufacturing the housing  106 . It will be appreciated by a person skilled in the art that the housing  106  can be manufactured using known methods including but not limited to e.g. casting and molding. 
     The terminal  108  is made from copper alloy. Other conductive materials including, but not limited to, phosphor bronze, and/or gold or tin plated materials may be used for manufacturing the terminal  108 . It will be appreciated by the person skilled in the art that the terminal  108  can be manufactured using known methods including but not limited to e.g. cutting and press forming. 
     The terminal  108  comprises a substantially U-shaped contact portion  110  which protrudes above the housing  106  with a closed end of the contact portion  110  facing away from the housing  106 . 
     A first leg  114  of the contact portion  110  extends substantially perpendicularly from the housing  106 . A second leg  116  of the contact portion  110  having a free end  111  is angled with respect to the first leg  114  of the U-shaped contact portion  110  in a quiescent state. The first leg  114  and the second leg  116  are arranged such that a width D 1  of an open end of the contact portion  110  is greater than a width D 2  of the closed end of the contact portion  110  and a width D 3  of the through-hole  112  is equal to or larger than the width D 2  of the closed end of the contact portion  110  but is smaller than the width D 1  of the open end of the contact portion  110 . The second leg  116  terminates substantially at a surface level  117  of the housing  106 . 
     As will be appreciated by a person skilled in the art, such an arrangement of the first and second legs  114 ,  116  of the contact portion  110  advantageously provides a resilient engagement between the contact portion  110  and a through-hole  112  of the PCB  104 , when the PCB  104  and the contact portion  110  are in a mated condition. The resilient engagement can ensure electrical contact between the contact portion  110  and contact traces (not shown) of the PCB  104 . The contact traces (not shown) of the PCB  104  are plated on an inner surface of the through-hole  112  for providing electrical connection. The resilient engagement provides a clipping effect which can reduce the likelihood of unwanted disengagement from the PCB  104 . 
     The contact portion  110  further comprises a protrusion  118 , which is disposed on the second leg  116  of the contact portion  110 . The protrusion  118  extends outwardly from the second leg  116  of the contact portion  110 . It will be appreciated by the person skilled in the art that the protrusion  118  will advantageously further facilitate a resilient engagement between the contact portion  110  and the through-hole  112  of the PCB  104 . 
     The terminal  108  further comprises a solder tail portion  120  extending beyond the housing  106 . An electrical connection of the compression connector  102  with another PCB (not shown) can be achieved by soldering the solder tail portion  120  onto the PCB (not shown). The solder tail portion  120  is of the surface mount type. It will be appreciated that other solder tail portion configurations are possible. 
       FIG. 2  shows a schematic cross-sectional view of an assembly  202  of the compression connector  102  and the PCB  104 . During the assembling of the compression connector  102  and the PCB  104 , the U-shaped contact portion  110  is compressed so that the contact portion  110  can be fitted into the through-hole  112  of the PCB  104 . 
     After the contact portion  110  is inserted into the through-hole  112 , the first and second legs  114 ,  116  of the contact portion  110  are substantially parallel. With the second leg  116  terminating substantially at the surface level  117  of the housing  106 , the contact portion  110  can be manufactured with a lower height while providing a reliable electrical connection between the contact portion  110  and the PCB  104 . With the first and second legs  114 ,  116  being substantially parallel when the PCB  104  and the contact portion  110  are in a mated condition, a resilient engagement between the contact portion  110  and a through-hole  112  of the PCB  104  is advantageously provided, and the reliable electrical connection provided. 
     The protrusion  118  of the second leg  116  and the first leg  114  are contacting the through-hole  112 . The protrusion  118  advantageously achieves a force distribution within the PCB  104  which can advantageously prevent deformation of the terminal  108 . It will be appreciated by a person skilled in the art that while the protrusion  118  is shown in  FIG. 2  at a mid point along the through-hole  112 , the protrusion  118  can be disposed at any determined location along the through-hole  112 . 
       FIG. 3  shows a schematic perspective cross-sectional view of an assembly  202  of the compression connector  102  and the PCB  104 . A plurality of terminals  108  is disposed in two rows along the housing  106 . The terminals  108  are arranged such that the orientation of the terminals  108  in a first row  302  is rotated by 180° with respect to a second row  304 . As will be appreciated by the skilled person in the art, the arrangement of the terminals  108  advantageously achieves the force distribution, indicated by the arrows within the PCB  104  in  FIG. 3 , which can advantageously prevent deformation of the terminal  108  when the substantially U-shaped contact portions  110  resiliently engage the through-holes  112  of the PCB  104 . 
     As shown in  FIG. 3 , the terminal  108  further comprises a curved portion  306  between the contact portion  110  and the solder tail portion  120  for resiliently supporting the contact portion  110 . 
     The described connector and terminals provide a resilient engagement between the contact portions of the terminals and the through-holes of the PCB. Unwanted disengagement can be prevented without having to use an additional component such as a clamp to retain the connector to the PCB. A force distribution within the PCB for preventing deformation of the terminal is also achieved. 
     It will be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive. 
     It will be appreciated that modifications of the contact portions of the terminals are possible. For example, the contact portions can comprise a protrusion dimensioned so as to provide resilient engagement with an opening of a PCB. Similarly, the contact portions may comprise only one leg angled with respect to a second leg for resilient engagement without a protrusion. The leg having the free end may terminate below the surface level of the housing. 
     To provide resilient engagement, it is possible that the contact portions may comprise two angled legs and/or more than one protrusion. 
     Also, the shapes of the terminals and/or the housings are not limited. Other shapes can be used, including differently shaped contact portions, curved portions and solder tail portions. 
     Furthermore, it will be appreciated that different numbers of terminals per housing may be implemented.