A new anisotropic conductive film with arrayed conductive particles

A new anisotropic conductive film (ACF) incorporating arrayed metal conductors in an adhesive polymer film is proposed. A photoresist pattern with a number of round holes arrayed in triangular arrangement is formed on a stainless steel substrate. The holes are then electroplated to form metal bumps, using the substrate as a cathode. After removal of the photoresist, the substrate is laminated with a solid adhesive film. Finally, the ACF of arrayed metal bumps is obtained when the adhesive film is peeled off and the metal bumps are transferred from the substrate to the adhesive film. The superior interconnection properties of the proposed ACF, compared with conventional ACFs that rely on randomly distributed conductive particles, are attributed to the arrayed, uniformly sized particles in the adhesive film.