Electrically conductive adhesives based on thermoplastic polyurethane filled with silver flakes and carbon nanotubes

Flexible conductive adhesive could be used in flexible device electronic packaging. In this study, carbon nanotubes (CNTs) were used as one-dimensional conductive scaffolds to construct effective electrical networks among the silver flakes in electrically conductive adhesives (ECAs) for saving noble metal fillers and reducing the cost because CNTs used as conductivity fillers could bridge the neighboring silver flakes to accelerate the electron transport. The electrical, mechanical, and thermal properties have been enhanced after adding CNTs. The electrical conductivity increased 85.6% after 4.5 wt% CNT added into the 50 wt% Ag TPU adhesives. In addition, after the Ag flakes modified by succinic acid (SA), the electrical conductivity has also been improved. The development of highly conductive, flexible, and low cost ECAs will allow them to be widely used in flexible electronic devices packaging in the future.