A precision vertical interconnect technology

An interconnection technology that utilizes excimer laser drilled vias and computer-controlled plating to provide vertical (Z-axis) electrical connections in high-performance flexible circuits is described. Specifically, solid vias and hemispherical microcontacts are created with a 1-μm nearest-neighbor height precision for the microcontacts. A novel structural architecture that simplifies the ground plane connections for impedance controlled flex circuits is used. The technology is particularly suitable in the DC to 2-GHz frequency range, where large numbers of parallel connections and or multiple make-and-break connections are desirable. This technology was implemented with a polyimide substrate and nickel contacts, although the technology is applicable to other substrate and contact metallurgies