Abstract: A pressure sensor has a stem in which a pressure introduction hole into which a pressure medium is introduced and a diaphragm deformable according to the pressure of the pressure medium are formed, and a strain detecting element which is arranged on the diaphragm via an insulating film and being configured to output a detection signal according to the deformation of the diaphragm. The strain detecting element is configured to have a portion made of polysilicon. A low doping layer having a higher electrical resistivity than polysilicon and a higher crystallinity than the insulating film is arranged between the insulating film and the strain detecting element.

Abstract: An electronic element mounting substrate includes a substrate including, on a first upper surface, a mounting region in which an electronic element is mounted, a frame body located on the first upper surface of the substrate and surrounding the mounting region, a channel extending through the frame body outward from an inner wall of the frame body, and an electrode pad located on the first upper surface of the substrate or an inner surface of the frame body. The channel is located above or below the electrode pad.

Abstract: The invention relates to an optical semiconductor device housing package comprising a base having a mounting portion on an upper surface of which an optical semiconductor device is mounted; a frame attached to the base so as to encircle the mounting portion, the frame having a through-hole in one side thereof; a cylindrically shaped fixing member into which an optical fiber is inserted, the cylindrically shaped fixing member being fixed to the through-hole of the frame; a light-transmitting member attached to one end portion of the fixing member; and a lid member mounted on an upper face of the frame, for hermetically sealing the optical semiconductor device, wherein the light-transmitting member is formed of amorphous glass.