Electrical connector and method of making it

Abstract

The present invention is an electrical connector in which a substrate (such as a printed circuit board or PCB) includes a plurality of apertures (or vias) and some of those apertures are filled with two materials to improve the characteristics of the electrical interconnection. The preferred process of crating the filled vias includes the steps of plating the vias with an electrically-conductive material to create an electrically-conductive path between portions of the substrate and components associated with the substrate and partially filling the apertures, then filling at least a portion of the apertures or vias with a second or different filling material to seal at least apart of the electrically conductive path through the plating. The second filling material may be chosen to provide thermal compensation for the connection.

1 .- 23 . (canceled) 
     
     
         24 . An electrical connector comprising:
 a substrate having a first surface and a second surface and carrying electrical contacts on at least one surface and a plurality of apertures extending between the first surface and the second surface, said electrical contacts including an elastic portion;   an electrically-conductive material which extends through at least one of the plurality of apertures and electrically couples the first surface and the second surface; and   an additional material in addition to the conductive material which is included within at least one of the plurality of apertures, said additional material sealing at least a portion of the electrically-conductive material from exposure to the environment outside the substrate, said additional material chosen to have a coefficient of thermal expansion approximating the coefficient of thermal expansion of at least one of the substrate and the electrically-conductive material.   
     
     
         25 . An electrical connector of the type described in  claim 24  wherein the additional material is chosen to have a coefficient of thermal expansion between the coefficient of thermal expansion of the substrate and the coefficient of the electrically conductive material. 
     
     
         26 . An electrical connector of the type described in  claim 24  wherein the additional material includes a thermosetting epoxy material. 
     
     
         27 . An electrical connector of the type described in  claim 24  wherein the additional material is filled with silica particles. 
     
     
         28 . An electrical connector of the type described in  claim 24  wherein the additional material is filled with a material with high thermal conductivity. 
     
     
         29 . An electrical connector of the type described in  claim 24  wherein the additional material includes a fusible metal. 
     
     
         30 . A method of making an electrical connector comprising the steps of:
 providing a connector substrate with a plurality of apertures;   defining a plurality of electrically-conductive contacts on a flat sheet of conductive material, forming the flat sheet into a three-dimensional form with a plurality of elastic electrical contacts, attaching the three-dimensional conductive sheet with a plurality of electrical contacts to the substrate and singulating the electrical contacts;   providing an electrically-conductive path through at least one of the apertures and attaching at least one of the electrical contacts to the electrically-conductive path through the substrate;   choosing an additional material which has a coefficient of thermal expansion approximating the coefficient of thermal expansion of at least one of the substrate, the electrical contact and the electrically-conductive path; and   inserting the chosen additional material into the aperture to protect the electrically-conductive path by providing a sealing of at least part of the electrically-conductive path.   
     
     
         31 . A method including the steps of  claim 30  wherein the step of filling includes the step of choosing a fill material with a characteristic based on at least one characteristic of the substrate. 
     
     
         32 . A method including the steps of  claim 30  wherein the step of filling includes the step of choosing a fill material with a characteristic based on at least one characteristic of the electrically conductive path. 
     
     
         33 . A method including the steps of  claim 30  wherein the step of filling includes the step of choosing a fill material with a characteristic based on at least one characteristic of at least one of the substrate, the electrical contact and the electrically conductive path through the substrate. 
     
     
         34 . A method including the steps of  claim 30  wherein the step of choosing a fill material includes the step of choosing a material with a suitable amount of silica included therein to provide the desired coefficient of thermal expansion. 
     
     
         35 . An electrical connector comprising:
 a substrate including an insulating body, at least one mounting surface and a plurality of apertures extending at least partially through the substrate;   a set of electrical contacts carried on the mounting surface of the substrate and at least some of the electrical contacts being proximate at least some of the apertures, the electrical contacts including at least one elastic spring contact;   a first conductive material within at least some of the apertures and in contact with at least one of the electrical contacts providing an electrical path coupling the one electrical contact with a second surface of the substrate, said first conductive material only partially filling the apertures into which the first conductive material is within; and   a second material in the same aperture in which the first conductive material has been inserted, said second material covering at least part of the first conductive material and filling at least part of the aperture, said second material having a coefficient of thermal expansion which approximates the coefficient of thermal expansion of at least one of the substrate and the first conductive material.   
     
     
         36 . An electrical connector of the type described in  claim 35  wherein the substrate has a second mounting surface comprising mounting pads for at least one chosen from solderballs and surface mount attachments, where at least one of the mounting pads is electrically connected to at least one of the electrical contacts. 
     
     
         37 . An electrical connector of the type described in  claim 35  wherein the second material comprises a thermosetting epoxy. 
     
     
         38 . An electrical connector of the type described in  claim 35  wherein the second material has a coefficient of thermal expansion which has been chosen based on the coefficient of thermal expansion of the first material. 
     
     
         39 . An electrical connector comprising:
 a substrate having a first surface and a second surface and carrying electrical contacts on both surfaces and a plurality of apertures extending between the first surface and the second surface, said electrical contacts including an elastic portion;   an electrically-conductive material which extends through at least one of the plurality of apertures and electrically couples the first surface and the second surface; and   an additional material in addition to the conductive material which is included within each of the plurality of apertures, said additional material sealing the apertures to prevent ingress of fluid materials through the apertures;   a sealing mechanism around the perimeter of at least the connector first surface, said sealing mechanism comprising a compliant material, said sealing mechanism providing a fluid ingress-inhibiting seal around the perimeter of the connector area containing the electrical contacts when compressed against a mating surface of an electrical component, such as a printed circuit board.   
     
     
         40 . An electrical connector of the type described in  claim 39  wherein the sealing mechanism comprises an O-ring. 
     
     
         41 . An electrical connector of the type described in  claim 39  wherein the sealing mechanism results from the use of a compliant coverlay material on the connector surface. 
     
     
         42 . An electrical connector of the type described in  claim 41  wherein the compliant coverlay material is comprised of an elastomer. 
     
     
         43 . An electrical connector of the type described in  claim 41  wherein the compliant coverlay material is comprised of a closed cell foam. 
     
     
         44 . An electrical connector of the type described in  claim 41  wherein the compliant coverlay material is comprised of an open cell foam which deters ingress of liquid when sufficiently compressed. 
     
     
         45 . An electrical connector of the type described in  claim 39  wherein a sealing mechanism is included on both surfaces of the connector. 
     
     
         46 . An electrical connector comprising:
 a substrate including an insulating body, at least one mounting surface and a plurality of apertures extending at least partially through the substrate;   a set of electrical contacts carried on the mounting surface of the substrate and at least some of the electrical contacts being adjacent to or on top of at least some of the apertures, the electrical contacts including at least one elastic spring contact;   a first conductive material within at least some of the apertures and in contact with at least one of the electrical contacts providing an electrical path coupling the one electrical contact with a second surface of the substrate, said first conductive material only partially filling the apertures into which the first conductive material is within; and   a second material in the same aperture in which the first conductive material has been inserted, said second material covering completely filling the apertures; and   a sealing mechanism around at least the perimeter of at least the connector first surface, said sealing mechanism comprising a compliant material, said sealing mechanism providing a seal which inhibits the ingress of liquids from around the perimeter of the connector area containing the electrical contacts when compressed against a mating surface of an electrical component, such as a printed circuit board.