Anisotropic alignment of nickel particles in a magnetic field for electronically conductive adhesives applications

Anisotropically conductive adhesives were developed by magnetic alignment of conductive nickel particles in a non-conductive epoxy matrix. Conductivity occurs in the direction of the magnetic field applied to the adhesive film. The effects of magnetic and conducting nickel filler type (i.e. powders, filaments, flakes, and fibers), resin viscosity, and the magnitude of aligning magnetic field on the electrical properties of the resulting anisotropic adhesive were investigated. The electrical resistance of the anisotropic adhesive was measured using the four-point probe method. The resistance of the filled adhesive decreased with increasing viscosity and the intensity of the magnetic field.