Flip-Chip Bonding Using Aerosol Jet Printed Silver Nanoparticles for RF Applications
Year: 2025
Type: article
Abstract: This work demonstrates a new approach to flip-chip bonding of RF chips using aerosol jet printed silver nanoparticle (NP) microbumps for advanced packaging and heterogeneous integration. Here, chips with gold pads are flip-chip mounted on silver printed microbumps on an alumina substrate at low temperature and pressure. This process is similar to cold-welding in that it joins nanostructures without intense heating or other external forces. While silver NPs have been explored extensively for power electronics bonding, only large bonding pad sizes ($\gt 1 \mathrm {mm} ^{2}$) were possible due to manual application of the NPs, limiting their usefulness for RF structures. We demonstrate miniaturized bonding pad sizes using aerosol jet printing (AJP) to precisely control the application of the NPs. The same printed material is used for both transmission line conductors and the microbump bonds. Thermal cycling (between room temperature and$125~^{\circ }$C) over 500 cycles was carried out to demonstrate the first-order reliability of the bonding process. RF performance is presented using a broadband microwave nonlinear transmission line (NLTL).
Institution: Michigan State University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,645
OpenAlex ID: W7076052525