Lead frame

摘要

In a lead frame having a number of square dimples arranged on the rear side of a bed portion in a lattice form of a pitch t, each side of the square dimples is disposed to form a predetermined angle relative to either of X-Y axes of the lattice extending in lateral and longitudinal directions of the bed portion. The square dimples may be provided at entire intersecting points between two sets of lines extending in parallel with the X and Y axes, or every other intersecting points of the same, so that an equal pitch of t or 2t is maintained between the dimples arranged in X and Y directions.