title: Self-Patterning of Silica/Epoxy Nanocomposite Underfill by Tailored Hydrophilic-Superhydrophobic Surfaces for 3D Integrated Circuit (IC) Stacking.
abstract: As microelectronics are trending toward smaller packages and integrated circuit (IC) stacks nowadays, underfill, the polymer composite filled in between the IC chip and the substrate, becomes increasingly important for interconnection reliability. However, traditional underfills cannot meet the requirements for low-profile and fine pitch in high density IC stacking packages. Post-applied underfills have difficulties in flowing into the small gaps between the chip and the substrate, while pre-applied underfills face filler entrapment at bond pads. In this report, we present a self-patterning underfilling technology that uses selective wetting of underfill on Cu bond pads and Si3N4passivation via surface energy engineering. This novel process, fully compatible with the conventional underfilling process, eliminates the issue of filler entrapment in typical pre-applied underfilling process, enabling high density and fine pitch IC die bonding.
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.
authors.forename: Chia-Chi
authors.initials: CC
authors.lastname: Tuan
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.
authors.forename: Nathan Pataki
authors.initials: NP
authors.lastname: James
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.
authors.forename: Ziyin
authors.initials: Z
authors.lastname: Lin
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.|School of Electromechanical Engineering and Key Laboratory of Mechanical Equipment Manufacturing & Control Technology of Ministry of Education, Guangdong University of Technology , Guangzhou 510006, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.
authors.forename: Kyoung-Sik
authors.initials: KS
authors.lastname: Moon
authors.affiliation: Department of Materials Science, Fudan University , 220 Handan Road, Shanghai 200433, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.|Department of Electronic Engineering, The Chinese University of Hong Kong , Shatin, Hong Kong.
authors.forename: C P
authors.initials: CP
authors.lastname: Wong
keywords: 3D packaging; dewetting; self-patterning; superhydrophobic; underfill