Contact Resistance Comparison of Flip-Chip Joints Produced with Anisotropic Conductive Adhesive and Nonconductive Adhesive for Smart Textile Applications

Abstract

For applications in smart textiles, flip-chip bonding was applied with either an anisotropic conductive adhesive (ACA) or a nonconductive adhesive (NCA) to a heat-resistant fabric and a Si substrate as a reference. The average contact resistances of the flip-chip joints produced with each adhesive on each substrate were evaluated with varying the Cu and Sn thicknesses inversely over the range of 0–15 µm to maintain a total thickness of 15 µm of the Cu/Sn bump. The contact resistances of the flip-chip joints produced with ACA on Si, NCA on Si, ACA on fabric, and NCA on fabric were 6.5–12.2 mΩ, 15.6–26.5 mΩ, 5.3–10.2 mΩ, and 5.5–10.1 mΩ, respectively.