In situ hydrothermal synthesis of silver nanoparticle based on graphene and their application for electrically conductive adhesive

Electrically conductive adhesive based on epoxy and conductive materials, which have been considered as the new promising material for electronic packaging because of the advantages of low processing temperature, fine pitch interconnect and environmentally friendly. The silver nanoparticle based on graphene have been used in the electrically conductive adhesive as a result of the excellent electrical material. The number of effective conductive paths were improved after doping silver nanoparticle based on graphene into epoxy. So silver nanoparticle based on graphene was prepared in situ hydrothermal method via silver-ammonia solution and graphene oxide as initial solution without other supported reagents. Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction and Raman spectroscopy were applied to analyze the morphologies and structures of silver nanoparticle based on graphene. Then electrically conductive adhesive was prepared by mixing silver nanoparticle based on graphene, silver flakes and epoxy together. The electrical properties of electrically conductive adhesive were tested by four-point probe method after cured at 150 °C for 2 h. The result shows that silver nanoparticles were dispersed on the surface of graphene layers uniformly and the average diameter of nanosilver particles is 80 nm. The electrical properties of electrically conductive adhesive was 7.0×10-4 Ω·cm when the nanosilver based on graphene reached 0.2 %, which compared with electrically conductive adhesive (1.1×10-3 Ω·cm) without nanosilver based on graphene was improved.