Development and Electrical Performance of Low Temperature Cu-Sn/In Bonding for 3D Flexible Substate Integration

Abstract

An innovative bonding approach applied to flexible substrate bonding is proposed in this research. Thin-film metal pad is fabricated as bonding medium to provide vertical stacking. As compared to other bonding methods, such as anisotropic conductive film (ACF) or non-conductive paste (NCP), thin-film metal pad bonding approach provides the most attractive advantage of fine-pitch. The bonding condition at low temperature exhibits good electrical performance, proving its great potential in the applications of flexible substrate stacking.