NIMS Researcher Visits NTU

日本北海道大學-米澤徹教授

Tetsu Yonezawa

Birth: 1965/08/14 Kobe, JAPAN

 

1992       Exchange PhD Student, Swiss Federal Institute of Technology, Lausanne

1994       Dr. Eng. from Univ. Tokyo (Applied Chemistry)

1994      JSPS Postdoctral fellow

1994       Postdoctral fellow in IRC (Institute for Research on Catalysis)

1996       Assistant Professor of Kyushu Univ. (Organic Synthesis Lab.)

2001       Associate Professor of Nagoya Univ. (Nanoparticles, Ceramics)

2002       Associate Professor of Univ. Tokyo (Metal Complex, Nanoparticles)

2009       Full Professor of Hokkaido Univ.

 

Awards:

2002       Carrier Award, Colloid and Interface Div., Chemical Soc. Jpn.

2005       Young Scientist Lectureship Award, Kansai Div., SPSJ (Society for Polymer Science, Japan)

2009       Hot Article Award, Analytical Sciences

2011       SPSJ (Society for Polymer Science, Japan) Hitachi Chemical Award

 

Title 

New Copper Fine Particle Systems for Low Temperature Sintering

 

Abstract:

A conductive paste was prepared with submicrometer-sized copper fine particles of 130 nm. After drying, an oxidation-reduction two-step sintering process was proposed for these submicrometer-sized copper fine particles to obtain low-resistivity layers at a very low temperature as 200 or 150 C. The optimized conditions gave a low resistivity of 8.2 × 10^-6 Ω cm, even when the particles were covered by a common polymer. Our results suggest that the formation of the small copper oxide prominences on the surface of the copper fine particles could be reduced at low temperatures, forming connected submicrometer-sized metallic copper particles. Recently, we have further succeeded to establish a novel low cost sintering process of copper fine particles to copper conductive layer at as low as 100 °C without reductive gas flow. Sintering of a mixture of copper particles and copper-based metal-organic-decomposition (MOD) ink, gave a copper film with high packing density and low resistivity (9 × 10^-6 Ω m). This novel process may open a new strategy in the field of printed electronics.