| 摘要 |
PURPOSE:To avoid the damage of a reflection preventing film during the process of assembly by a method wherein a protection film having less photo absorption is formed on the reflection preventing film. CONSTITUTION:In a photo trigger thyristor element, the reflection preventing film 5 is formed on the photo receiving surface 4 thereof in adjacency, and thereafter an Si dioxide protection film 8 is formed on the film 5 in adjacency. Thereby, it is the film 8 that received damages during the process of beveling the periphery and the process of surface treatment, and the film 5 is not damaged. The photo trigger thyristor element thus completed is assembled along with a light guide and a matching agent 6 under the condition of attachment of the film 8. The use of Si dioxide having a photo refractive index nearly equal to that of the matching agent for the film 8 allows little reflection loss at the boundary surface between the film 8 and the matching agent, because of the nearly equal photo refractive index, and, even when the film 8 is subject to damages in a later process, they do not impart adverse influences to the photo transmittance. |
