Method for electrically interconnecting large contact arrays using eutectic alloy bumping

1. Field of the Invention Methods of forming arrays of electrical interconnects between substrates are provided. These methods allow the use of large interconnect bump arrays to physically and electrically connect substrates without the need to use excess pressure on the substrates to form the interconnects, thus reducing damage to the substrates. To form the interconnects, an array of bumps is formed on a first substrate from a material that forms a eutectic composition with a second material. An array of bumps composed of the second material is formed on the second substrate. The arrays are aligned and the bumps contacted at a temperature above the eutectic temperature of the eutectic composition. Each of the bumps on the first substrate melts and diffuises into the corresponding bumps on the second substrate to form the interconnects.