Patent ID: 7547577

Claim:
A method of making a circuitized substrate assembly comprising: providing first and second circuitized substrate subassemblies, each of said circuitized substrate subassemblies including at least one dielectric layer and at least one conductive layer including a plurality of metallic conductor pads as part thereof; aligning said first and second circuitized substrate subassemblies relative to one another such that each of said plurality of metallic conductor pads of said first circuitized substrate subassembly are aligned with a corresponding metallic conductor pad of said plurality of metallic conductor pads of said second circuitized substrate subassembly in a facing manner; positioning a flowable dielectric layer between said first and second circuitized substrate subassemblies, said dielectric layer including a plurality of openings therein, each of said openings aligning with a respective pair of aligned and facing metallic conductor pads of said first and second circuitized substrate subassemblies; depositing a quantity of metallic solder paste on one of said metallic conductor pads of each of said pairs of said aligned and facing metallic conductor pads of said first and second circuitized substrate subassemblies; depositing a quantity of organometallic solder paste by screen or stencil printing on the remaining one of said metallic conductor pads of each of said pairs of said conductive pads, said organometallic solder paste having a composition different from the composition of said metallic paste; and bonding said first and second circuitized substrate subassemblies together using heat and pressure in such a manner that the metallurgies of said metallic and organometallic solder paste and said metallic conductor pads in said pairs of said aligned and facing metallic conductor pads of said first and second circuitized substrate subassemblies are combined to form an electrical connection therebetween and the material of said flowable dielectric layer will flow into said openings to substantially fill said openings and physically contact and surround said electrical connections without adversely affecting said electrical connections.