EECS Seminar: Anisotropic Conductive Films (ACF) Interconnection Technology for Wearable Electronics Applications

Kyung W. Paik
McDonnell Douglas Engineering Auditorium (MDEA)

Kyung W. Paik, Ph.D.
Department of Materials Science and Engineering
Nano-Packaging & Interconnect Laboratory
Korea Advanced Institute of Science and Technology (KAIST)

Abstract: Due to the increasing demand for higher performance, greater flexibility, smaller size and lighter weight in mobile electronic products, there is a growing need for wearable electronic products. Wearable watches, glasses, wrist bands, shoes and clothes have been recently introduced in the market.

To realize wearable electronic products, there should be four core electronic hardware technologies - (1) flexible semiconductor, (2) flexible display, (3) flexible battery and (4) flexible packaging & interconnection technologies. In the flexible semiconductor devices, ICs are thinned down to nanometer thickness and then transferred to a polymer film. However, much more development is needed for the real applications of flexible semiconductors in the near future. In contrast, flexible displays are already available by introducing OLED (organic LED) realized on polymer base films. And flexible batteries are also demonstrated by several companies by adapting solid electrolytes. However, there has been little development on flexible packaging & interconnection areas. As one of the promising flexible packaging and interconnection technologies, flexible printed circuits (FPCs) substrates and ACF materials-based packaging and interconnection methods will provide the solution for realizing wearable electronic products. In the electronic packaging technology for wearable electronics, flexible IC packaging structures such as COF(Chip On Flex)/CIF(Chip In Flex) can provide an immediate technical solution for semiconductor IC package flexibility. In addition, FOF(Flex On Flex) and FOF(Flex On Fabric) technologies using FPC substrates and ACF interconnection materials become very important, because ACF interconnection provides excellent electrical flexibility compared with conventional solder- or socket-based interconnection methods, which have a limitation of bending and flexing. This  will show how the ACF technology can be successfully used for the COF/CIF flexible chip packaging and FOF interconnection and assembly methods for wearable electronics applications.

Biography: Kyung W. Paik received a Ph.D. from Cornell University Department of Materials Science and Engineering in 1989. After earning his doctorate, he worked as senior technical staff at General Electric Corporate Research and Development, where he was involved with the research and development of materials and processes of GE High Density Interconnect (HDI) multichip module technology and power I/C packaging. in 1995, he joined the Korea Advanced Institute of Science and Technology (KAIST) as a professor in the Department of Materials Science and Engineering, and served as dean of student affairs from 2008 - 2010 and vice president of research from 2011 - 2013. In his Nano-Packaging and Interconnect Laboratory (NPIL), he has been working in the areas of Anisotropic Conductive Adhesives (ACA) materials and processing, 3-D TSV interconnect materials, solders and MEMS & display packaging technologies, and he has published more than 160 SCI journal papers and has more than 40 issued and pending US patents. Paik has been a member of the IEEE-CPMT, IMAPS, and SEMI. And he also has been actively involved in numerous international electronic packaging conferences such as ECTC, IMPACT, EMAP, EPTC, and so on as an organizer, technical committee, international liaison, session chair and invited speaker.