A lead frame has a pair of side frames each having a plurality of positioning holes and spaced apart from each other in a width direction of the lead frame. At least one section bar extends between the pair of side frames. First lead sections extend from the section bar and are arranged at predetermined intervals along the width direction of the lead frame. Second lead sections extend from the section bar along the width direction of the lead frame and are disposed in confronting and spaced-apart relation to the respective first lead sections in a longitudinal direction of the lead frame to define a frame area extending between the pair of side frames. Each of the second lead sections has a pair of separate and independent protruding portions disposed adjacent one another.