Robust FBEOL and UBM structure of C4 interconnects
View Patent ↗A microcircuit article of manufacture comprises an electrical conductor electrically connected to both a first microcircuit element at a site comprising a first connector site having a first connector site axis and a second microcircuit element at a site comprising a second connector site having a second connector site axis. The first microcircuit element and the second microcircuit element are separated by and operatively associated with a layer comprising a first electrical insulator, whereas the conductor and the first microcircuit element are separated by and operatively associated with a layer comprising a second electrical insulator. At least one of the first electrical insulator layer and the second electrical insulator layer comprise a polymeric electrical insulator. In another embodiment, both electrical insulator layers comprise polymeric insulator layers. The microcircuit includes a UBM and solder connection to a FBEOL via opening. Sufficiently separating the first connector site axis and the second connector site axis so they are not concentric decouples the UBM and solder connection to the FBEOL via opening to substantially eliminate or minimize inter alia, electromigration and the white bump problem typical of lead free solders employed in C4 systems. A process comprises manufacturing this type of microcircuit article.
1. A microcircuit article of manufacture comprising an electrical conductor electrically connected to both a first microcircuit element at a site comprising a first connector site having a first connector site axis and a second microcircuit element at a site comprising a second connector site having a second connector site axis, said first microcircuit element and said second microcircuit element being separated by and operatively associated with a layer comprising a first electrical insulator, said electrical conductor and said first microcircuit element being separated by and operatively associated with a layer comprising a second electrical insulator, said first connector site axis and said second connector site axis are not concentric, at least one of said first electrical insulator and said second electrical insulator comprise a polymeric electrical insulator, and one of said connector sites is operatively associated with a conductor comprising a copper column.
2. A microcircuit article of manufacture comprising an electrical conductor electrically connected to both a first microcircuit element at a site comprising a first connector site having a first connector site axis and a second microcircuit element at a site comprising a second connector site having a second connector site axis, said first microcircuit element and said second microcircuit element being separated by and operatively associated with a layer comprising a first electrical insulator, said electrical conductor and said first microcircuit element being separated by and operatively associated with a layer comprising a second electrical insulator, where said first connector site axis and said second connector site axis are not concentric, at least one of said first electrical insulator and said second electrical insulator comprise a polymeric electrical insulator, said first connector site is positioned in said first insulator layer and said second connector site is positioned in said second insulator layer.
3. A process of making a microcircuit article of manufacture comprising in any order, electrically connecting an electrical conductor to both a first microcircuit element at a site comprising a first connector site having a first connector site axis and a second microcircuit element at a site comprising a second connector site having a second connector site axis, separating said first microcircuit element and said second microcircuit element by a layer comprising a first electrical insulator, separating said conductor and said first microcircuit element by a layer comprising a second insulator, and aligning said first connector site axis and said second connector site axis so they are not concentric, wherein at least one of said first electrical insulator and said second electrical insulator comprise a polymeric electrical insulator, and operatively associating one of said connector sites with a connector comprising a copper column.
4. A process of making a microcircuit article of manufacture comprising in any order, electrically connecting an electrical conductor to both a first microcircuit element at a site comprising a first connector site having a first connector site axis and a second microcircuit element at a site comprising a second connector site having a second connector site axis, separating said first microcircuit element and said second microcircuit element by a layer comprising a first electrical insulator, separating said conductor and said first microcircuit element by a layer comprising a second insulator, and aligning said first connector site axis and said second connector site axis so they are not concentric, wherein at least one of said first electrical insulator and said second electrical insulator comprise a polymeric electrical insulator, said first connector site and said second connector site comprise via openings in said insulators, and said first connector site is positioned in said first insulator layer and said second connector site is positioned in said second insulator layer.