Patent Document

BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to electrical connectors and more specifically, to elastomeric connectors suitable for interconnecting circuit boards and electrical devices, and a retention member for holding elastomeric connectors.  
         [0002]     An increasing complexity of electronic assemblies in smaller packages are generating a need for new connectors to interconnect electronic components. For example, liquid crystal displays, vibratory motors, speakers and microphones are now being employed in devices of smaller and smaller size, such as cellular phone products and hand held devices. As the components become smaller and the terminals to connect the components are located closer together, known connectors are proving incapable of establishing reliable electrical connections.  
         [0003]     The use of elastomeric connectors has become increasingly popular in some electronic devices because the connectors are readily adaptable in size and geometry to meet a large variety of applications. One type of elastomeric connector typically includes alternating layers of dielectric elastomer, such as silicon rubber, and an elastomer filled or doped with electrically conductive material such as silver particles, graphite particles, conductive fabrics, wires, etc. The dielectric elastomer layers are sandwiched between the conductive layers and are of sufficient thickness to insulate the conductive layers from one another and therefore prevent the formation of electrically conductive or leakage pathways between the conductive layers. The alternating dielectric and conductive layers provide a connector having a large number of conductive pathways in a small volume for closer contact spacing.  
         [0004]     Elastomeric connectors are typically used for board-to-board, flex circuit-to-board, and component-to-board applications in mobile communications, portable electronic entertainment systems, hand held instrumentation and other space constrained electronic products. The elastomeric connectors are typically positioned within a dedicated cavity of the electronic product such that the elastomeric connectors have a surface-to-surface compression connection with the various components and/or boards. However, handling the elastomeric connectors as a separate component during assembly causes issues in manufacturability and ease of assembly, thus leading to increased assembly costs.  
         [0005]     One approach that has been developed to ease assembly includes the use of a supporting boot that may be molded from an elastomeric material, such as silicone rubber, and formed around the elastomeric connector. Other approaches use a separately provided supporting boot fabricated from an elastomeric material, such as silicone rubber, that may be assembled with the elastomeric connector prior to mounting the boot/connector assembly into the intended electronic product. However, such supporting boots increase the number of components in the electronic product, increase the assembly time and the assembly cost for the electronic product, and increase the overall size of the electronic component.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0006]     In one aspect, a connector assembly is provided including an elastomeric connector and a non-elastomeric holder configured to receive and maintain the elastomeric connector therein.  
         [0007]     Multiple elastomeric connectors may be mounted to the non-elastomeric holder. Optionally, the holder includes a body extending between first and second opposing surfaces, and the body defines a recess configured to receive the elastomeric connector therein. In one embodiment, the body surrounds the recess. In another embodiment, the recess is exposed to an exterior portion of the body. Optionally, the holder may include at least one dispensing well opening to and communicating with the recess, wherein the well is configured to receive a binding agent therein for retaining the elastomeric connector within the recess. The dispensing wells may include angled side walls to define a retaining feature for the binding agent. In one embodiment, the body may define a first recess and a second recess, and the dispensing well may extend between and open to each of the first and second recesses. Optionally, the first recess may extend in a first arcuate path, and the second recess may extend in a second arcuate path that is positioned radially inward with respect to the first recess.  
         [0008]     In another aspect, a retention member is provided for supporting an elastomeric connector having a first contact interface, a second contact interface. The retention member includes a non-elastomeric body extending between first and second opposing surfaces, and a recess having a side wall extending between the first and second surfaces. The recess is configured to receive the elastomeric connector therein such that the first and second contact interfaces of the elastomeric connector are exposed on each of the first and second surfaces of the body. A dispensing well extends from the first surface along the side wall of the recess. The dispensing well opens to the recess and includes a retaining feature. The well is configured to receive a binding agent configured to bond to each of the non-elastomeric body and the elastomeric connector for retaining the elastomeric connector within the recess.  
         [0009]     In a further aspect, a connector assembly is provided including a first elastomeric connector having a plurality of alternating elastomeric conductors and elastomer insulators. The first elastomeric connector has first and second contact interfaces spaced apart from one another and extending generally perpendicular to the conductors and insulators. The connector assembly also includes a second elastomeric connector having a plurality of alternating elastomeric conductors and elastomer insulators. The second elastomeric connector has first and second contact interfaces spaced apart from one another and extending generally perpendicular to the conductors and insulators. A holder includes a body extending between first and second opposing surfaces, and the body defines a first recess housing the first elastomeric connector and a second recess housing the second elastomeric connector. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1A  is an exploded perspective view of an exemplary elastomeric connector assembly including multiple elastomeric connectors and a holder for the elastomeric connectors in accordance with the present invention.  
         [0011]      FIG. 1B  is an enlarged view of a portion of the elastomeric connector shown in  FIG. 1 .  
         [0012]      FIG. 2  is a top perspective view of the elastomeric connector assembly shown in  FIG. 1  and depicting the elastomeric connectors installed within the holder.  
         [0013]      FIG. 3  is an exploded perspective view of another exemplary elastomeric connector assembly including multiple elastomeric connectors and a holder for the elastomeric connectors in accordance with an alternative embodiment of the present invention.  
         [0014]      FIG. 4  is a top perspective view of the elastomeric connector assembly shown in  FIG. 3  and depicting the elastomeric connectors installed within the holder. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]      FIG. 1A  is an exploded perspective view of an exemplary elastomeric connector assembly  10  including multiple elastomeric elements or connectors  12  and a retention member or holder  14  for the elastomeric connectors  12 .  FIG. 1B  is an enlarged view of the elastomeric connector  12 .  FIG. 2  is a top perspective view of the elastomeric connector assembly  10  shown in  FIG. 1  and depicting the elastomeric connectors  12  installed within the holder  14 . The connector assembly  10  may be utilized in an electronic product or device (not shown) having an application such as, for example, mobile communications, portable electronic entertainment, hand held instrumentation or another space constrained electronic application. More specifically, the connector assembly  10  may be utilized for board-to-board, flex circuit-to-board, or component-to-board applications within the electronic products or devices. Additionally, the connector assembly  10  may accommodate different connection geometries or connection patterns within the circuit board, flex circuit, or other electronic components such as polar, co-planar, arrayed or multi-level geometries or patterns.  
         [0016]     The elastomeric connectors  12  include alternating non-conductive layers  20  and conductive layers  22 . The non-conductive layers  20  are fabricated from a dielectric or insulating material, such as silicone rubber, and the conductive layers  22  are fabricated from a material such as a known particle filled silicone elastomer. The non-conductive layers  20  and the conductive layers  22  extend substantially perpendicular to a longitudinal axis  24  of the connector  12 , in a face-to-face relationship to one another in a continuous strip. The alternating non-conductive and conductive layers  20  and  22  of the elastomeric connector  12  provide a large number of conductive pathways through the elastomeric connector  12  in a relatively small volume, and the non-conductive layers  20  prevent current flow from one conductive layer  22  to another within the elastomeric connector  12 .  
         [0017]     In the illustrated embodiment, the connector  12  is of a generally rectangular shape and includes a pair of outer insulation elements  26  with the non-conductive and conductive layers  20  and  22  therebetween. The elastomeric connector  12  includes opposed top and bottom surfaces  28  and  30  extending between the upper and lower edges of the outer insulation elements  26 . Each of the top and bottom surfaces  28  and  30  interface with, for example, a surface of a circuit board, a flex circuit, or another electronic component (not shown) associated with the electronic product. The conductive layers  22  in the elastomeric connector  12  therefore establish a plurality of conductive paths between each of the components, circuits, or circuit boards interfacing with the top and bottom surfaces  28  and  30  of the connector  12 .  
         [0018]     The holder  14  is provided to secure the multiple connectors  12  in a position or orientation to interface with the various components, circuits, or circuit boards when the electronic product is assembled. The holder  14  includes a frame or body  32  having a plurality of notches or recesses  34  for receiving the elastomeric connectors  12 . In the illustrated embodiment, the body  32  is generally rectangular in shape and includes an opening  36  within the interior portion of the holder  14 . The opening  36  provides a reduced product cost and weight, and provides an area to position other components of the electronic product. In an exemplary embodiment, the body  32  of the holder  14  is fabricated from a rigid or semi-rigid material such as, for example, a metal material, a polypropylene material, a polycarbonate material, a polyethylene material, a liquid crystalline plastic material, a polyamide material, a polyetherimide material, or the like. As such, a liquid binding agent used to secure the elastomeric connector  12  to the holder  14 , as will be described in detail below, is selected to facilitate bonding to each of the silicone rubber material of the elastomeric connector  12  and the metal or plastic material of the holder  14 . Optionally, the binding agent may be an adhesive. Alternatively, another binding agent may be used.  
         [0019]     The body  32  includes a first or upper surface  38  and a second or lower surface  40 . The first and second surfaces  38  and  40  are generally planar and are separated from one another by a distance  42 . The body  32  also includes first and second opposed longitudinal side walls  44  and  46 , and first and second opposed lateral side walls  48  and  50 . An outer edge  52  extends between each of the first and second surfaces  38  and  40  along the longitudinal and lateral side walls  44 ,  46 ,  48 , and  50 . Moreover, the recesses  34  extend inwardly from the outer edge  52  of the body  32  and extend entirely between the first and second surfaces  38  and  40 . In an exemplary embodiment, the holder  14  includes recesses  34  in each of the side walls  44 ,  46 ,  48 , and  50  of the body  32 . In an illustrative embodiment, the holder  14  includes one recess  34  in each of the lateral side walls  48  and  50 , and two recesses  34  in each of the longitudinal side walls  44  and  46 . However, more or less recesses  34  may be included in each of the side walls  44 ,  46 ,  48 , and  50 . In an exemplary embodiment, the recesses  34  are exposed to the exterior of the holder  14 .  
         [0020]     The recesses  34  are defined by a side wall  54  extending between the first and second surfaces  38  and  40 . In an exemplary embodiment, the recesses  34  are substantially rectangular, and the side wall  54  includes a longitudinal portion  56  and opposed lateral portions  58 . The lateral portions  58  extend perpendicular with respect to the adjacent outer edge  52  of the body  32 , and the longitudinal portion  56  extends perpendicular to the lateral portion  58 . As such, boxed out or notched out portions define the recesses  34  along the outer edge  52  of the body  32 . When assembled, as illustrated in  FIG. 2 , the elastomeric connectors  12  are positioned within the notched out recesses  34  and engage the side walls  54  of the recesses  34 .  
         [0021]     The holder  14  includes dispensing wells  60  positioned adjacent to each recess  34 . In the illustrated embodiment, two dispensing wells  60  are associated with each recess  34 . Each dispensing well  60  opens to the first or upper surface  38  of the body  32  such that the liquid binding agent may be delivered to the dispensing well  60 . Optionally, dispensing wells  60  may be provided on both the upper and lower surfaces  38  and  40 . Each dispensing well  60  opens to the adjacent recess  34  such that the liquid binding agent may bond to the elastomeric connector  12  within the recess  34 . As such, the binding agent is selected to facilitate creating a chemical bond with each of the holder and the elastomeric connector  12 . In an exemplary embodiment, the dispensing wells  60  are oriented along the longitudinal portion  56  of the recess side wall  54 . As such, the liquid binding agent is attached to a single insulation element  26  of each elastomeric connector  12 .  
         [0022]     In an exemplary embodiment, each dispensing well  60  includes a keystone or keying feature  62  to retain and secure the binding agent within the dispensing well  60 . As such, the retaining feature  62  provides additional retention properties for the elastomeric connectors  12  in addition to the chemical bond between the holder  14  and the binding agent. In one embodiment, the walls of the dispensing well  60  may be angled outward from the opening to the recess  34  to define the retaining features  62 . As such, once the binding agent cures, or is otherwise bonded to each of the elastomeric connector  12  and the holder  14 , the binding agent resists movement of the elastomeric connector  12  away from the body  32  during handling or assembly of the electronic product. Optionally, the retaining feature  62  may include a rib or flange (not shown) extending from the body  32  into the dispensing well  60  such that the binding agent at least partially surrounds the rib or flange to provide resistance to movement of the elastomeric connector  12 .  
         [0023]     The holder  14  may be provided with mounting holes, recesses or alignment pins  64  for accurately positioning the assembly  10  in a final mounting position within the electronic product or device. Moreover, it will be recognized that the shape of the holder  14  may be varied to accommodate mounting requirements in different applications. As such, the elastomeric connector assembly  10  is capable of surface mounting a plurality of elastomeric connectors  12  as a single assembly, thus reducing assembly time and cost.  
         [0024]      FIG. 3  is an exploded perspective view of an alternative elastomeric connector assembly  110  including multiple elastomeric connectors  112  and a holder  114  for the elastomeric connectors  112  in accordance with an alternative embodiment of the present invention.  FIG. 4  is a top perspective view of the elastomeric connector assembly  110  shown in  FIG. 3  and depicting the elastomeric connectors  112  installed within the holder  114 . As with the connector assembly  10 , the connector assembly  110  may be utilized in an electronic product or device (not shown) having a space constrained electronic application.  
         [0025]     The elastomeric connectors  112  are fabricated in a similar manner as the elastomeric connectors  12  described above with reference to  FIGS. 1 and 2 . However, the elastomeric connectors  112  have a generally arcuate or curved shape. Specifically, each elastomeric connector  112  is substantially semi-circular in an exemplary embodiment.  
         [0026]     The holder  114  is provided to secure the multiple connectors  112  in a position or orientation to interface with the various components, circuits, or circuit boards when the electronic product is assembled. The holder  114  includes a frame or body  116  having a plurality of openings or recesses  118  for receiving the elastomeric connectors  112 . In an illustrative embodiment, the body  116  is generally circular in shape and includes an opening  120  within the interior portion of the holder  114 . In an exemplary embodiment, the body  116  of the holder  114  is fabricated from a rigid or semi-rigid material such as, for example, a polypropylene material, a polycarbonate material, a polyethylene material, a liquid crystalline plastic material, a polyamide material, a polyetherimide material, or the like.  
         [0027]     The body  116  includes a first or upper surface  122  and a second or lower surface  124 . The first and second surfaces  122  and  124  are generally planar and are separated from one another by a distance  126 . An outer edge  128  defines the perimeter of the body  116  and extends between each of the first and second surfaces  122  and  124 . The holder  114  includes a radially extending inner ring  130 , a middle ring  132 , and a radially extending outer ring  134 . The opening  120  is defined by an interior portion of the radially extending inner ring  130 , and the outer edge  128  of the body  116  defines an exterior portion of the radially outer ring  134 . The radially extending inner and outer rings  130  and  134  are joined to the middle ring  132  by a joining wall  136 . In the illustrated embodiment, the joining walls  136  are substantially aligned with one another. Alternatively, the joining walls  136  may be offset with respect to one another. Additionally, the holder  114  may include more or less than two joining walls  136  between each of the rings  130 ,  132 , and  134 .  
         [0028]     The recesses  118  are defined by each of the rings  132 ,  134 , and  136 . In an exemplary embodiment, the holder  114  includes first and second radially extending outer recesses  140  and  142 , respectively, and first and second radially extending inner recesses  144  and  146 . The radially extending outer recesses  140  and  142  extend between the radially extending outer ring  134  and the middle ring  132 . Additionally, the radially extending outer recesses  140  and  142  are separated from one another by the joining walls  136  extending between the outer ring  134  and the middle ring  132 . Moreover, the radially extending inner recesses  144  and  146  extend between the radially extending inner ring  130  and the middle ring  132 , and the radially extending inner recesses  144  and  146  are separated from one another by the joining walls  136  extending between the inner ring  130  and the middle ring  132 . However, more or less recesses  118  may be included in the holder  114 . When assembled, and as illustrated in  FIG. 4 , the elastomeric connectors  112  are positioned within the recesses  118  and engage the side walls of the recesses  118 . Optionally, the recesses  118  may include ribs or flanges  148  extending from the side walls of the recesses  118 . The ribs or flanges  148  are sized and position the elastomeric connectors  112  within the recesses  118 .  
         [0029]     The holder  114  includes dispensing wells  150  positioned adjacent to each recess  118 . In an exemplary embodiment, each dispensing well  150  is in fluid communication with multiple recesses  118 . Optionally, each dispensing well  150  may communicate with a radially inner recess  144  or  146  and a radially outer recess  140  or  142 . Additionally, more than one dispensing well  150  may extend between each recess  118 . Each dispensing well  150  opens to the first or upper surface  122  of the body  116  such that a liquid binding agent may be delivered to the dispensing well  150 . Each dispensing well  150  also opens to the adjacent recesses  140  or  142  and  144  or  146  such that the liquid binding agent in each dispensing well  150  may bond to an inner and an outer elastomeric connector  112 .  
         [0030]     In an exemplary embodiment, each elastomeric connector  112  may function as a retaining or keying feature to secure the binding agent within the dispensing well  150 . Specifically, the inner elastomeric connector  112  functions as a retaining feature for the adjacent outer elastomeric connector  112  to resist movement of the outer elastomeric connector  112  away from the body  116  during handling or assembly of the electronic product. Similarly, the outer elastomeric connector  112  functions as a retaining feature for the adjacent inner elastomeric connector  112  to resist movement of the inner elastomeric connector  112 . Optionally, each dispensing well  150  may include a rib or flange (not shown) extending from the body  116  into the dispensing well  150  such that the binding agent at least partially surrounds the rib or flange to provide resistance to movement of the elastomeric connectors  112 .  
         [0031]     The holder  114  may be provided with mounting holes, recesses or alignment pins  152  for accurately positioning the assembly  110  in a final mounting position within the electronic product or device. Moreover, it will be recognized that the shape of the holder  114  may be varied to accommodate mounting requirements in different applications.  
         [0032]     An elastomeric connector assembly  10  or  110  is thus provided having multiple elastomeric connectors  12  or  112  mounted thereto. The connectors  12  or  112  are grafted or bonded within recesses  34  or  118  in the holder  14  or  114 . To increase the robustness of the assembly  10  or  110 , the holders  14  or  114  include retaining features to reduce the stress on the chemical bond between the binding agent and the holder  14  or  114 . As a result, the elastomeric connector assembly  10  or  110  is capable of surface mounting a plurality of elastomeric connectors  12  or  112  as a single assembly, thus reducing assembly time and cost.  
         [0033]     While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.

Technology Category: 5