Patent ID: 7821347

Claim:
A surface-mount crystal oscillator, comprising: a crystal blank; an IC chip on which an oscillating circuit using said crystal blank is integrated, and which has an IC terminal on at least each of four corner portions, said IC chip being in a substantially rectangular shape; a housing body having a substantially rectangular recess housing said IC chip; a plurality of circuit terminals which are provided on an inner bottom surface of said recess, and to which said IC terminals are fixed via bumps; and external terminals respectively provided at four corner portions of an opening end surface surrounding said recess in said housing body, and electrically connected to said circuit terminals, wherein in each of at least three vertices out of vertices of the inner bottom surface of said recess, said external terminal corresponding to the vertex is formed on said opening end surface to be in contact with a longer side and a shorter side of an outer perimeter of said recess with said vertex as an inflection point, an exposed part in which the inner bottom surface of said recess is exposed is formed between the circuit terminal which is the closest to the vertex and the external terminal corresponding to said vertex such that the inner bottom surface is exposed at least at said vertex, and a boundary between said opening end surface and the inner bottom surface of said recess can be discriminated by difference of color of said external terminal and color of said exposed part thereby enabling discrimination of a position of said vertex by image recognition.