Mariko Hatamura

Ink-jet Printing of Nano Materials and Processes for Electronics Applications

Ag metallic particles from nano-scale to submicron-scale are combined with organic solvent to provide fine circuits and interconnection. Ag nanoparticle pastes have been successfully adopted to ink-jet wiring and the multilayered circuit layers in a SiP structure. Ink-jet printing with Ag nano particle pastes demonstrated the potentials of the new printed electronics technology. Lowering process temperature for Ag nanoparticle pastes finally reached room temperature wiring in air atmosphere.

Low-Temperature Wiring with Ag Nanoinks [Nanopackaging]

In this article, the mechanisms of these low-temperature curable inks are briefly reviewed. The dispersant removal by washing in alcohols for the nanoparticle ink and the decomposition behavior of the β-ketocarboxylate ink were clarified by thermal and microstructural analyses. The sintering and growth behaviors were also examined.

Novel Room Temperature Wiring Process of Ag Nanoparticle Paste

Ag nanoparticles protected by dodecylamine were formed into paste and successfully sintered at room temperature in air atmosphere. In order to remove the dodecylamine dispersant, Ag nanoparticles printed as lines on glass substrates were dipped in methanol for 10 s to 7200 s. As a result, the sintered wires possess excellent low resistivity, 7.3times10-7 Omegam after 7200 s dipping. From in-situ electrical resistance measurement, the electrical resistance of Ag nanoparticles becomes smaller as sintering time increases. Microstructural observation on room temperature sintering revealed that, as dipping time increases, Ag nanoparticles agglomerate to be coarsened, and connection among particles becomes clearer. Thus, a novel room temperature wiring method for Ag nanoparticles has been successfully developed in air atmosphere.