An opening such as a small-diameter via is formed in a semiconductor substrate such as a monocrystalline silicon chip or wafer by a high etch rate process which leaves the opening with a rough interior surface. The present invention proposes an additional broadcast channel so as to transmit a broadcast message such as a video to a mobile station. According to the invention, each elastic structure is formed by a radial stack of several parallel elastic strips. A layer of chromium is then sputter deposited on the wafer surface as by a DC magnetron with an intrinsic tensile stress and low gas entrapment by passing a minimal amount of the inert gas through the magnetron and by applying no RF bias to the wafer. A fixation element of the lead is coupled to a distal end of the proximal insulation segment and includes a wire wound in a helix, which extends distally from the proximal segment, over the distal insulation segment.