Synthesis and Characterization of Nanowire-Based Anisotropic Conductors

Abstract

We investigated the potential of commercially available porous templates to be used for the fabrication of functional anisotropic conductors. A galvanostatic deposition technique was used to fabricate arrays consisting of 200 nm diameter nanowires inside the pores of polycarbonate membranes. A tape lift-off procedure allowed the complete removal of any residual metal from both sides of the polymer membrane to form an anisotropic conductive film. The 10 microm thick film has roughly 3 x 10(8) nanowires per cm2, and it showed near zero electrical resistance perpendicular to the surface while appearing completely open to circuits between any points on the surface. The preparation of the film, characterization using SEM, AFM, and resistance measurements are presented. The 1D conductivity of these membranes may have many potential applications for microelectronic interconnects for packaging technologies.

Investigation of Process Parameters and Characterization of Nanowire Anisotropic Conductive Film for Interconnection Applications

“…Whereas track-etch polymer membranes, made of flexible polycarbonate, can be used to directly fabricate such composite film for both electrical [16], [17] and thermally [18] conductive purposes. The characterization of such a film as an anisotropic conductor was first proposed in [16]. The main challenge with track-etch membranes is the porosity (5%-20%) and quality of the pores.…”

Ion track enabled multiple wire microvia interconnects in printed circuit boards

“…Furthermore, the metallized foils can be seen as analogous to the anisotropically conductive films (ACF) that are commonly used for flipchip and other packaging applications. A proof-of-principle of metallized ion track membranes as ACFs was demonstrated in [39] using polycarbonate foils. By developing the process in polyimide as is presented in this paper, the metallized foils can be further structured using lithography, allowing for more complex packaging structures and wiring lines.…”