Microelectronic packages having an array of resilient leads
A connection component including a flexible substrate having a top surface and a bottom surface, a layer of a compliant, dielectric material overlying the top surface of the substrate, the compliant material layer having a top surface remote from the substrate, an array of flexible, conductive leads having first ends attached to terminals accessible at the bottom surface of the substrate and second ends adjacent the top surface of the compliant layer, wherein each lead comprises a core of a first conductive material surrounded by a layer of a second conductive material, the second conductive material having a greater yield strength than the first conductive material.
1. A connection component comprising:
a flexible substrate having a top surface and a bottom surface;
a layer of a compliant, dielectric material overlying the top surface of said substrate, said compliant material layer having a top surface remote from the substrate;
an array of flexible, conductive leads having first ends attached to terminals accessible at the bottom surface of said substrate and second ends adjacent the top surface of said compliant layer, wherein each said lead comprises a core of a first conductive material surrounded by a layer of a second conductive material, the second conductive material having a greater yield strength than the first conductive material.
2. The connection component as claimed in claim 1 , further comprising contacts attached to the second ends of said leads, wherein said contacts are accessible at the top surface of said compliant layer.
3. The connection component as claimed in claim 1 , wherein said flexible substrate is a flexible dielectric sheet made of a polymeric material.
4. The connection component as claimed in claim 1 , wherein the core of said first conductive material is selected from the group consisting of aluminum, gold, copper, tin, and their alloys, and combinations thereof.
5. The connection component as claimed in claim 1 , wherein the second conductive material surrounding the first conductive material is selected from the group consisting of nickel, copper, cobalt, iron, gold, silver, platinum, noble metals, semi-noble metals, tungsten, molybdenum, tin, leads, bismuth, indium and their alloys.
6. The connection component as claimed in claim 1 , wherein the second conductive material surrounding the first conductive material is selected from the group consisting of nickel, and alloys thereof.
7. The connection component as claimed in claim 2 , further comprising:
a sacrificial layer covering the top surface of said compliant layer and said contacts accessible at the top surface of said compliant layer, wherein said sacrificial layer is removable for exposing said contacts for electrically connecting said connection component with an electronic element.