Patent ID: 7165899

Claim:
A package for housing an optical semiconductor element comprising: a base body made of a platy metal having a through bore drilled all the way through from an upper principal surface to a lower principal surface thereof; a lid body formed in a cylindrical shape and made of a metal, the lid body including an upper end face having a through hole formed therein and a lower end which is left opened and joined to an outer periphery of the upper principal surface of the base body; a light-transmitting member bonded around an opening of the through hole of the lid body; and an input/output terminal joined to the upper principal surface of the base body so as to cover the through bore, the input/output terminal including: a first plate portion formed of a dielectric substance, which is disposed uprightly on the upper principal surface of the base body so as to lie across the through bore; a line conductor formed on one principal surface of the first plate portion so as to extend from one base body-side edge to another edge opposite thereto of the one principal surface; a second plate portion formed of a dielectric substance, which is stacked on the one principal surface of the first plate portion, with its one base body-side end face made flush with the first plate portion; a metal plate formed so as to be made higher than the first plate portion, which is stacked on another principal surface of the first plate portion, with its one base body-side end face made flush with the first plate portion; and a lead terminal attached to a part of a lower surface of the input/output terminal which lies inside the through bore, the lead terminal being electrically connected to the line conductor.