Method of mounting a circuit component and joint structure therefor

Abstract

A joint structure and method for bonding together two components, such as when attaching an electrical circuit element to a conductor on a substrate. The joint structure comprises a mesh infiltrated by a solder material, in which the mesh is preferably formed of a material having a higher thermal conductivity than the solder material. The joint structure is able to offer improvements in thermal conductivity, electrical conductivity, reflow processing, and stress distribution between the structures it connects. Each of these attributes of the joint structure can be tailored to some degree by the choices of materials for the mesh and the solder material.

1 . A semiconductor assembly comprising a heat-generating integrated circuit chip that is attached to a heatsink on a substrate with an electrically-conductive joint structure located between and contacting a surface of the integrated circuit chip and a surface of the heatsink, the joint structure comprising an electrically-conductive flexible mesh infiltrated by a solder material that bonds together the integrated circuit chip, the heat sink and the mesh, a solder-free portion of the mesh extending outside of the joint structure and from between the integrated circuit chip and the heatsink to define a flexible jumper to the integrated circuit chip, the mesh being formed of woven strands of copper or copper alloy wire, the mesh substantially establishing the thickness of the joint structure.  
     
     
         2 . (canceled)  
     
     
         3 . (canceled)  
     
     
         4 . (canceled)  
     
     
         5 . The semiconductor assembly according to  claim 4   1 , further comprising an interconnect strap contacting a second surface of the integrated circuit chip and a third component on the substrate, the interconnect strap comprising an electrically-conductive flexible mesh having first and second portions at the second surface of the integrated circuit chip and the third component, respectively, and an intermediate portion therebetween, the first and second portions of the mesh being infiltrated by a solder material that bonds the mesh to the second surface of the integrated circuit chip and to the third component while the intermediate portion is substantially free of a solder material so as to remain flexible.  
     
     
         6 . The semiconductor assembly according to  claim 5 , wherein the solder material of the interconnect strap has a lower melting temperature than the solder material of the joint structure.