Controlled Synthesis of 3D Silver Fractal Flowers for High-Performance Conductive Adhesives.

Abstract

Silver-based electrically conductive adhesives (ECAs) are widely used in the connection, conduction, and packaging of electronic components. However, commercial ECAs typically contain more than 90 wt % Ag fillers, creating an urgent demand for low-Ag-content alternatives that maintain excellent performance. To address this issue, Ag with 3D structures has significant low-content and structural advantages in efficiently constructing 3D conductive networks in the ECAs system. Herein, three types of Ag-based fractal flowers with 3D branched structures (Ag FW-I, Ag FW-II, and Ag FW-III) were successfully synthesized using a novel, facile, and efficient chemical reduction method. The Ag FW-II particles served as the primary conductive framework, while Ag FW-I and Ag FW-III acted as auxiliary fillers, bridging gaps and connecting isolated regions. When the Ag FW-I, Ag FW-II, and Ag FW-III contents were optimized to 17.5, 50, and 12.5 wt %, respectively, the resulting ternary ECAs can deliver the lowest bulk resistivity of 1.15 × 10-4 Ω·cm and a high adhesion strength of 12.88 MPa. These Ag FWs-based ECAs demonstrate the best balance of conductivity and adhesion strength, offering a promising solution for the electronic packaging industry.