Method of manufacturing an interconnect device having coplanar contact bumps

A method for forming an electrical interconnect device having contact bumps, including the steps of:

• establishing a mold in which a plurality of flat topped contact bumps are to be formed, said mold including a relatively thin and flat layer of first material and a relatively thick layer of a second material, said second layer being selectively removable;
• defining sites in said second material at which the contact bumps are to be formed;
• selectively removing said second material at each of said sites to expose a flat area of said first material at each site to form a hole of predetermined size and shape in said second material intersecting said first material at said flat area;
• forming an electrically conductive contact element in each of said holes conforming to the shape of said hole;
• each of said electrically conductive contact elements having a flat surface coplanar with the flat surface of each of the other of said conductive elements;
• forming a plurality of electrical circuit lines on said second material, each of said circuit lines including at least one of said contact elements;
• bonding to said circuit lines a laminate of a layer of dielectric material and a layer of conductive material, said dielectric material being bonded to said circuit lines and separating said circuit lines from said layer of conductive material;
• forming at least one via hole through said laminate to at least one of said circuit lines;
• forming a via connection from said layer of conductive material to said at least one circuit line through said via hole;
• and
• removing said contact elements from said mold to define an interconnect device having a plurality of circuit lines with at least one contact bump in each circuit line, the contact bumps all being coplanar, and a conductive layer connected by said at least one via to said at least one circuit line, said conductive layer constituting a voltage plane.