Investigation of Materials and Processes for High Temperature Interconnection in Electronics
Professor Hiroshi NISHIKAWA
Joining and Welding Research Institute
Date & Time
Thursday, 29 June 2023
Room 7-34 and 7-35
Haking Wong Building, HKU
As a recent trend, the silicon carbide (SiC) is of particular interest for semiconductor device. The SiCpower device provides the possibility to develop the next-generation power conversion circuit with high efficiency and high power density. Compared with the conventional silicon (Si) device, the SiC device can operate with significant lower power loss and higher operating temperature, which contributes to miniaturization and higher performance of power modules. To assemble these power devices, the high-temperature bonding process as a die bonding process is a key technology. The EU RoHS directive currently exempts the use of high-lead-containing solders such as Pb-5Sn and Pb-10Sn solders in electronic packaging. However, there is no guarantee that the exemption will last. A strong drive thus exists to find lead-free alternatives for the next-generation power devices. We have proposed a solid-state bonding process without solvents using a metal sheet with nanostructured surface. A feasibility study has been conducted to determine whether the metal sheet with nanostructured surface can be used as a die bonding material for power devices. In this talk, I will introduce new approach on die bonding materials and processes using the metal sheet with nanostructured surface. I will introduce a manufacturing process of nanoporous sheets in dealloying  and a pressure-assisted nanoporous bonding (NPB) for die bonding process. Basic experimental test results such as joint strength and interfacial behavior with a substrate will be also explained.
 J. Erlebacher, M.J. Aziz, A. Karma, N. Dimitrov, K. Sieradzki: Evolution of nanoporosity in dealloying, Nature, 410 (2001), 450-453.
Hiroshi Nishikawa has received his MS degree in 1999 and Dr. of Engineering in 2002 from Osaka University, Japan. He joined at Collaborative Research Center for Advanced Science and Technology, Osaka University in 2002 as Assistant Professor. From 2005 he has been working at Joining and Welding Research Institute, Osaka University and now is Professor. He focuses his study on micro-joining process and interconnections for electronics packaging for more than 20 years. And the recent research objectives of his research group are for electronics packaging to develop advanced joint materials, to establish advanced micro joining processes, and to enhance the highly reliable joints based on the control of interfacial structure and performance.