| abstract |
An integrated circuit (IC) package substrate has a dielectric layer and a micro filled via formed substantially in the center of a hole in the dielectric layer. The IC package substrate has at least one chip bonding pad and one ball attach pad that are electrically coupled to each other by the micro filled via. The micro filled via is formed of a material called a "micro filled via material" that includes a binding material and optionally includes a number of particles (between 0%-90% by volume) dispersed in the binding material. The binding material can be any material, such as a polymer that is either conductive or nonconductive. The particles can be formed of any conductive material, such as a conductive polymer or a conductive metal (e.g. copper or gold). An electrical conductor can be originally formed simply by contact between conductive particles located adjacent to each other. In an optional step, the micro filled via is subjected to a programming current (in a step called "programming") to lower the resistance of an originally formed electrical conductor, or to originally form an electrical conductor by break down of a dielectric material. The IC package substrate can be formed in either a cavity up or a cavity down configuration. |