Patent ID: 7465651

Claim:
A method comprising: forming a substrate having an upper surface upon which an integrated circuit having a lower surface is to be mounted at a distance, wherein the integrated circuit comprises a dielectric layer of a dielectric material of dielectric constant less than 3.6, wherein the integrated circuit comprises a plurality of relatively low yield strength, reflowable, lead-free solder contacts, wherein the solder contacts have a melting point in the range of 150-270 degrees Centigrade, wherein the substrate comprises a plurality of conductors; and forming a plurality of relatively high yield strength, substantially cylindrical, conductive, copper, columns projecting from the upper surface and coupled to selected ones of the plurality of conductors, wherein the columns are formed of material having a melting temperature more than 100 degrees Centigrade higher than that of the solder contacts, the columns to physically connect to corresponding solder contacts of the integrated circuit through an operation in which the solder contacts are melted without melting the columns, wherein the columns have a height that is greater than 60% of the distance, wherein the substrate comprises at least one dielectric layer of organic material and at least one conductive layer containing the selected ones of the plurality of conductors, and wherein the fracture toughness of the integrated circuit dielectric layer is less than that of the substrate dielectric layer.