Development of an anisotropic conductive adhesive film (ACAF) from epoxy resins

A thermoset type anisotropic conductive adhesive film (ACAF), which electrically connects an ITO glass and a flex circuit both having conducting pattersn of less than 100 μm in pitch, has been developed. In this development, bisphenol A and bisphenol F epoxy resins were tested to formulate an ACAF with easy‐to‐handle tackiness, flexibility, and strenght. A curing agent that gives fast cure and long shelf‐life properties to the epoxy resin was also selected. The tensile stress–strain responses of obtained adhesive films were successfully used for determining the formulation. Good aftercure physical properties (electrical and mechanical) were obtained. Durability against high temperature and high humidity were also tested to confirm long‐term stability of the conduction of this ACAF. © 1995 John Wiley & Sons, Inc.