Disclosed herein are anisotropic conductive particles contained in
anisotropic conductive adhesive films, which can be used in circuit board
mounting applications. The conductive particles can exhibit superior
electrical reliability. Further disclosed are polymer particles having
good compressive deformability and recoverability from deformation
without being ruptured when an adhesive film containing conductive
particles including the polymer particles as a component is interposed
and compressed between connection substrates, thereby achieving a
sufficient contact area between the particles and the connection
substrates. Because the polymer particles have a spherical shape, a
uniform particle diameter, and a narrow particle diameter distribution,
the particles can exhibit enhanced conducting properties.