Patent ID: 9125333
Filing Date: 2015-09-01
Classification: H01L,H05K

Abstract:
1. A conductive pad adapted to create an electrical connection, comprising: a conductive substrate having a surface; a variable-composition nickel alloy layer disposed above the conductive substrate and having a thickness of no more than 800 nm in a direction extending away from the surface; and a conductive layer disposed above the variable-composition nickel alloy layer, wherein the variable-composition nickel alloy layer has a variable nickel concentration which varies within the nickel alloy layer in the direction of the thickness, wherein the variable-composition nickel alloy layer comprises a minor constituent selected from the group consisting of boron, carbon, phosphorus, and tungsten, wherein the concentration of the minor constituent adjacent the surface is at least 1 percent by weight, and wherein the concentration of the minor constituent adjacent the conductive layer is at least 1 percent by weight; wherein at least over a portion of the surface, the concentration of the minor constituent varies in the direction of the thickness throughout the variable-composition nickel alloy layer; wherein at least over said portion of the surface, the variable-composition nickel alloy layer has a variable boron concentration within the nickel alloy layer; wherein the boron concentration varies between about 0% and about 5% by weight within the nickel alloy layer; wherein the variable composition nickel-alloy layer has first and second surfaces, the first surface being closer to the substrate than the second surface, and wherein the concentration of boron is higher at the first surface than the boron concentration at the second surface.