A method of manufacturing an electrically driven L.E.D. lamp assembly (20) comprises disposing an electrically insulative coating (24) on a thermally conductive substrate (22). A plurality of light emitting diodes (26) is secured to the coating (24). A coupling agent is disposed on a tape portion (48) of a foil tape (46), and the foil tape (46) is secured to the coating (24) with the coupling agent in predetermined spaced lengths (42) along the coating (24) to establish discrete and electrically conductive spaced lengths (42) with the light emitting diodes (26) disposed between the spaced lengths (42). Each light emitting diode (26) includes a pair of electrical leads (32) which are secured to the spaced lengths (42) to electrically interconnect the light emitting diodes (26).