Self-generated local heating induced nanojoining for room temperature pressureless flexible electronic packaging

Peng Peng; Anming Hu; Adrian P Gerlich; Yangai Liu; Y Norman Zhou

doi:10.1038/srep09282

Self-generated local heating induced nanojoining for room temperature pressureless flexible electronic packaging

Sci Rep. 2015 Mar 19:5:9282. doi: 10.1038/srep09282.

Authors

Peng Peng¹, Anming Hu², Adrian P Gerlich³, Yangai Liu⁴, Y Norman Zhou¹

Affiliations

¹ 1] Centre for Advanced Materials Joining, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada [2] Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
² 1] Centre for Advanced Materials Joining, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada [2] Mechanical, Aerospace and Biomedical Engineering Department, University of Tennessee, 1512 Middle Drive, Knoxville, TN 37996-2210, US.
³ Centre for Advanced Materials Joining, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
⁴ School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083, China.

Abstract

Metallic bonding at an interface is determined by the application of heat and/or pressure. The means by which these are applied are the most critical for joining nanoscale structures. The present study considers the feasibility of room-temperature pressureless joining of copper wires using water-based silver nanowire paste. A novel mechanism of self-generated local heating within the silver nanowire paste and copper substrate system promotes the joining of silver-to-silver and silver-to-copper without any external energy input. The localized heat energy was delivered in-situ to the interfaces to promote atomic diffusion and metallic bond formation with the bulk component temperature stays near room-temperature. This local heating effect has been detected experimentally and confirmed by calculation. The joints formed at room-temperature without pressure achieve a tensile strength of 5.7 MPa and exhibit ultra-low resistivity in the range of 101.3 nOhm · m. The good conductivity of the joint is attributed to the removal of organic compounds in the paste and metallic bonding of silver-to-copper and silver-to-silver. The water-based silver nanowire paste filler material is successfully applied to various flexible substrates for room temperature bonding. The use of chemically generated local heating may become a potential method for energy in-situ delivery at micro/nanoscale.

Publication types

Research Support, Non-U.S. Gov't