Electronic package with concave lead end faces

1 . An electronic package comprising:

an electronic component including terminals;

a plurality of leads, at least some of the leads being electrically coupled to the terminals within the electronic package; and

a mold compound covering the electronic component and partially covering the leads,

wherein each of the leads include an exposed bottom face coplanar with a bottom surface of the mold compound and an exposed end face coplanar with one of a plurality of side surfaces of the mold compound, and

wherein for at least some of the leads, the exposed end face includes an hourglass shape including a concave recess over a rectangular portion of a base metal of the plurality of leads.

2 . The electronic package of claim 1 , wherein for each of the leads with the concave recess, the concave recess includes the mold compound.

3 . The electronic package of claim 1 , wherein for at least one of the leads with the concave recess, the concave recess includes a metal smear extending from the one of the leads with the concave recess.

4 . The electronic package of claim 1 ,

wherein for each of the leads with the concave recess, the exposed end face defines a first width adjacent to the bottom surface of the mold compound, a second width at the narrow portion, the second width further from the bottom surface than the first width, and a third width further from the bottom surface than the second width, each of the first width, the second width, and the third width being measured parallel to the bottom surface along the one of the plurality of side surfaces of the mold compound, and

wherein the second width is smaller than both the first width and the third width.

5 . The electronic package of claim 1 , wherein for each of the leads with the concave recess, the exposed end face includes a rectangular base portion adjacent to the bottom surface with the concave recess being further from the bottom surface than the rectangular base portion.

6 . The electronic package of claim 5 ,

wherein for each of the leads with the concave recess, the lead primarily includes a base metal extending to include the rectangular base portion of the exposed end face, but not the narrow portion of the exposed end face, and

wherein for each of the leads with the concave recess, the lead includes a seam between the rectangular base portion and the narrow portion.

7 . The electronic package of claim 6 , wherein the seam represents an interface between a metal grain structure of the base metal, and a metal grain structure of the narrow portion.

8 . The electronic package of claim 6 , wherein the seam represents an interface between a first metal composition the base metal, and a second metal composition of the narrow portion.

9 . The electronic package of claim 1 , wherein for each of the leads with the concave recess, a maximum width of the lead at the exposed end face is less than a maximum width of the lead along the exposed bottom face.

10 . The electronic package of claim 1 , further comprising wire bonds electrically coupling the terminals of the electronic component to the leads, the mold compound covering the wire bonds.

11 . The electronic package of claim 1 , wherein the electronic component includes a semiconductor die.

12 . A leadframe strip for an array of electronic packages comprising:

a patterned base metal forming leads for each of the array of electronic packages; and

a premold material filling a first partial etch of a first side of the base metal,

wherein the patterned base metal forms rectangular base portions of the base metal at lead ends of the leads on a second side of the base metal,

wherein each of the lead ends includes a second metal over the rectangular base portion of the lead end on the second side of the base metal, the second metal forming a narrow portion forming a concave recess on the rectangular base portion.

13 . The leadframe strip of claim 12 ,

wherein for each of the lead ends, the narrow portion defines a first width adjacent to the first side of the base metal, a second width at the narrow portion, the second width further from first side of the base metal than the first width, and a third width further from first side of the base metal than the second width, each of the first width, the second width, and the third width being measured parallel to the first side of the base metal, and

wherein the second width is smaller than both the first width and the third width.

14 . The leadframe strip of claim 12 , wherein for each of the leads, the lead includes a seam between the rectangular base portion and the narrow portion.

15 . The leadframe strip of claim 14 , wherein the seam represents an interface between a metal grain structure of the base metal, and a metal grain structure of the narrow portion.

16 . The leadframe strip of claim 14 , wherein the seam represents an interface between a first metal composition the base metal, and a second metal composition of the narrow portion.

17 . The leadframe strip of claim 12 , wherein for each of the leads, a maximum width of the lead at the lead end is less than a maximum width of the lead along the first side of the base metal.