A method for producing a lead frame includes press-punching a metal sheet to form the lead frame such that a radius of curvature at a corner of a lower face of each of electrodes is larger than a radius of curvature at a corner of an upper face of each of the electrodes while a radius of curvature at a corner of a lower face of each of hanger leads is smaller than a radius of curvature at a corner of an upper face of each of the hanger leads. The lead frame includes the electrodes, the hanger leads spaced apart from the electrodes, and an outer frame attached to the electrodes and the hanger leads. The lead frame partially defines a box-shaped package that defines a first recess having an opening defining by the support member and a bottom face at least partially formed by the electrodes.