| 摘要 |
PURPOSE:To inhibit the generation of flare by preventing light reflection inside the casing by a method wherein light reflection preventing films are formed on the inner surface of a metal frame and/or the inner surface of the casing body. CONSTITUTION:A metal layer 6 is provided with an optical window plate 9 via metal frame 7 and ceramic layer 8 so as to seal a chip 3 e.g. by electric welding. Further, the inner surface of the metal frame 7 is provided with a light reflection preventing film 11 by being coated with a black paint or the like of small reflectance, and, in the casing body 1, a light reflection preventing film 13 is similarly provided in the element mount periphery of the mount surface where the chip 3 is mounted. Incident light passing through the optical window plate 9 forms an image on the surface of the chip 3, and the incident light comes to irradiation also in the periphery of the chip 3; however, the reflection is blocked because of the light reflection preventing film 12 in the periphery. On the other hand, part of the reflected light on the surface of the chip 3 comes to irradiatio of the inner surfaces of the plate 9 and the metal frame 7; however, the reflection is blocked because the inner surface of the metal frame 7 is coated with the film 11. |
