OPTICAL PRINTING HEAD AND MANUFACTURE THEREOF

摘要

PURPOSE:To enhance the productivity and reliability of an optical printing head by a method wherein wire bonding is eliminated in a process for arranging and packaging a light-emitting diode array chip on a light transmittable board. CONSTITUTION:A plurality of electroconductor film 22 for circuit are arranged on the surface of a light transmittable board 21. On the light emitting surface side of a light emitting diode array chip 23, which is formed by integrating a plurality of light emitting diodes 24 in tandem, the metallic bumps 26 for the electrode terminals of the light-emitting diode are arranged. The light emitting diode array chip 23 is die-bonded onto the board 21 by turning facedown or under the condition that its light-emitting surface faces to the surface of the board and the metallic bumps 26 come into contact with the metal plating layer 27 of conductor film 22. The metallic bump 26 has the Young's modulus, which is higher than that of the metal plating layer 27. In addition, the film thickness of the metal plating layer 27 is larger than the fluctuating dimension of the height of the metallic bump 26.