A signal transfer film includes a base film, a lead line formed on the
base film and a passivation layer protecting the lead line. The
passivation layer includes a nonlinear edge portion formed at a boundary
region between the lead line and the passivation layer. The nonlinear
edge portion of the passivation layer disperses a stress concentrated to
the boundary region in various directions when the base film is bent.
Thus, the signal transfer film may prevent breaking of the lead line,
thereby enhancing yield thereof.