La soutenance de thèse de Caio César DE OLIVEIRA MENDES intitulée : « Amélioration de l’interconnexion des dispositifs de puissance par des nanofils de cuivre pour l’intégration dans les circuits imprimés« , aura lieu le mardi 19 novembre 2024 à 09 h 30 Amphithéâtre Concorde, Université Paul Sabatier Bat U4.
Ecole doctorale : GEETS – Génie Electrique Electronique,Télécommunications et Santé : du système au nanosystème
Composition du Jury :
Directeur de thèse : Jean-pascal CAMBRONNE
Rapporteurs :
– M. Cyril BUTTAY (Directeur de Recherche, INSA Lyon)
The rapid evolution of power electronics, particularly with the adoption of wide bandgap devices, has intensified the demand for advanced packaging solutions capable of handling high power densities, elevated temperatures, and high-speed switching. Traditional packaging methods, while reliable, often fall short of these requirements, underscoring the need for innovative interconnection technologies. This thesis explores the development and integration of copper nanowire-based interconnects as a promising solution for embedding power devices in printed circuit boards.
The research begins by addressing the limitations of conventional interconnection technologies and proposes nanowires as a viable alternative. Nanowires offer enhanced mechanical properties and compatibility with the small feature sizes of WBG devices. The manufacturing process of these interconnects, focusing on direct electrodeposition onto PCB substrates, marks a significant advancement over existing methods. Critical to this process is the use of an organized membranes, such as the InRedox, which allows for precise control over nanowire morphology and copper content.
Extensive morphological and electrical characterizations of the nanowire interconnects were conducted. The findings demonstrate that nanowires grown using the InRedox membrane exhibit superior quality, with higher copper density (60%) and lower resistance compared to traditional soldering and silver sintering technologies. This increased density is achieved even within thick copper layers, a capability that microvias lack. Additionally, the nanowire interconnects show promising electrical performance, with area-specific resistance values well within the range suitable for WBG applications. Thermal characterization further reveals that while nanowires offer improved performance over traditional soldering, microvias still excel in heat extraction due to the nature of pressed contacts present in the proposed nanowire interconnect.
