Low-Temperature Curable Photo-Active Anisotropic Conductive Films (PA-ACFs)

Abstract

Photo-active anisotropic conductive films (PA-ACFs) with curing temperatures below 120A degrees C were introduced using photo-active curing agents. The PA-ACFs showed no curing before UV activation, and the crosslinking systems of the PA-ACFs were not activated under fluorescent light exposure. However, after UV activation, the PA-ACFs were completely cured at 120A degrees C within 10 s. Flex-on-board (FOB) assembly using PA-ACFs had adhesion strength and joint resistances similar to those of the FOB assemblies using conventional epoxy-based ACFs. This study demonstrates that PA-ACFs provide reliable interconnection and minimal thermal deformation among all the commercially available ACFs, especially for low T (g) substrate applications.