Patent attributes
A semiconductor device includes a lead frame; a semiconductor chip mounted on the lead frame; and an encapsulation resin, wherein a convexo-concave portion including a plurality of concave portions is provided at a covered portion of the lead frame that is covered by the encapsulation resin, wherein the planer shape of each of the concave portions is a circle, the diameter of which is greater than or equal to 0.020 mm and less than or equal to 0.060 mm, or a polygon, the diameter of whose circumcircle is greater than or equal to 0.020 mm and less than or equal to 0.060 mm, and wherein a ratio S/S0 is greater than or equal to 1.7 where “S” is a surface area of the convexo-concave portion that is formed at a flat surface whose surface area is “S0”.
