Low Temperature Flex-on-Flex Assembly Using Polyvinylidene Fluoride Nanofiber Incorporated Sn58Bi Solder Anisotropic Conductive Films and Vertical Ultrasonic Bonding

Table 1

The material composition of conventional Ni ACFs, conventional Sn58Bi solder ACFs, and PVDF nanofiber/Sn58Bi solder ACFs.

ACF type	Conventional ACF	Solder ACF	Nanofiber solder ACF
Conductive particle content (wt.%)	30 wt.% Ni ball	20 wt.% Sn58Bi solder ball	15 wt.% Sn58Bi solder ball
Conductive particle size (𝜇m)	8 𝜇m	5∼15 𝜇m	5∼15 𝜇m
Nanofiber material	—	—	PVDF
Resin type	Epoxy	Epoxy	Epoxy