Effect of compression pressure on strength of low-temperature sinter bonding produced using silver formate

ABSTRACT

Novel pressure-assisted sinter bonding at 200°C using silver (Ag) formate particles was performed in air using an Ag-finished die and substrate to achieve a reliable Ag bondline even at high temperatures. The Ag formate particles, prepared by immersing Ag₂O particles for 3 min in a formic acid solution, indicated a pyrolysis reaction near 130°C, forming pure Ag and gases (carbon dioxide and hydrogen). With a paste prepared by mixing the Ag formate particles with α-terpineol, the bonding under 10 MPa exhibited an adequate shear strength of 270 MPa after 3 min. Moreover, a near-full-density structure was observed in the formed bondline after 10 min. Consequently, the compression pressure of 10 MPa resulted in significantly enhanced bondability with reduced void fraction in the formed Ag bondline.

KEYWORDS:

• Sinter bonding
• Ag formate
• compression pressure
• pyrolysis
• shear strength

Acknowledgements

This work was supported by the Materials & Components Technology Development Program (10080187) funded by the Ministry of Trade, Industry & Energy (MI, Korea).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Materials & Components Technology Development Program (10080187) funded by the Ministry of Trade, Industry & Energy (MI, Korea).

Notes on contributors

Yun-Ju Lee

Yun-Ju Lee received the bachelor's degree in materials science & engineering from Seoul National University of Science and Technology, Seoul, Korea, in 2000. Her current research interests are in the areas of wet synthesis of various particles and die bonding using a paste containing the particles.

Jong-Hyun Lee

Jong-Hyun Lee received the PhD in metallurgy and materials science from Hongik University, Seoul, Korea, in 2001. From 2001 to 2005, he was with ETRI, Daejeon, Korea, where he was involved in developing optoelectronic packages. In 2005, he was with the Memory Device Division, Samsung Electronics Corporation, Onyang, Korea. From 2006 to 2008, he was a senior researcher of Korea Institute of Industrial Technology (KITECH), Incheon, Korea, where he worked on electronic packaging materials and processes. Since 2008, he has been working as an assistant professor at the Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul, Korea. His current research interests are in the areas of electronic packaging materials and interconnection technologies.