TRANSMISSION TYPE PHOTOCOUPLER AND ITS MANUFACTURE

PURPOSE:To realize a transmission type photocoupler capable of improving use efficiency of light, by forming a parabolic surface in a light shielding body. CONSTITUTION:A light shielding body 19 is formed by using liquid crystal polymer or the like similar to a resin substrate 11. A primary molded body of transparent sealing resin 18 is subjected to secondary molding. The lower surface facing a light emitting element 12 is constituted as a parabolic surface having a focal point at the position of a light emitting element 12, in the manner which a light radiated from the light emitting element 12 has directivity of the lateral direction to a transmission trench 21 side. The lower surface of the light shielding body 19 which surface faces a photodetector 14 is constituted as a parabolic surface having a focal point at the position of the photodetector 14 in the manner in which the lateral direction light from the transmission trench 21 is converged on the photodetector 14. Hence, at the time of application, a light can be effectively converged on the photodetector 14 by constituting the parabolic surface in the light shielding body 19, and a surface mount transmission type photocoupler of high sensitivity can be realized.