Aerosol Jet® Printer as an Alternative to Wire Bond and TSV Technology for 3D Interconnect Applications

Abstract

Aerosol Jet deposition systems provide an evolutionary alternative to both wire bond and TSV technology. As part of the Vertical Interconnect Pillar (ViP™) process, the Aerosol Jet system prints high density three-dimensional (3D) interconnects enabling multi-function integrated circuits to be stacked and vertically interconnected in high performance System-in-Packages (SiP). The stacks can include two or more die, with a total height of ∼ 2 millimeters. The non-contact printing system has a working distance of several millimeters above the substrate allowing 3D interconnects to be printed with no Z-height adjustments. The Aerosol Jet printhead is configured with multiple nozzles and a closely coupled atomizer to achieve production throughput of greater than 19,000 interconnects per hour. The Aerosol Jet printer deposits silver fine particle ink to form connections on staggered die stacks. High aspect ratio interconnects, less than 30-microns wide and greater than 6-microns tall, are printed at sub 60-micron pitch. After isothermal sintering at 150° C to 200° C for 30 minutes, highly conductive interconnects near bulk resistivity are produced. Pre-production yields exceeding 80% have been realized. This paper will provide further details on the 3D printed interconnect process, current and planned production throughput levels, and process yield and device reliability status.