Lead-frame forming for improved thermal performance
AssigneeSTMicroelectronics S.r.l.
InventorsMichael J. Hundt, Tiao Zhou
Life of this patent
Estimating the term…
Abstract
A lead frame of a plastic integrated circuit package is fabricated in two steps. First, from a rectangular sheet of metal, lead fingers of the lead frame are formed. Second, the die pad of the lead frame is clamped and is simultaneously separated and downset from the lead fingers of the lead frame by shearing the lead frame with a mated punch die pair. Performing the separation and downset of the die pad from the lead fingers results in essentially no horizontal gap between the lead fingers and the die pad. The downset of the die pad with respect to the lead fingers results in a vertical separation between the die pad and the lead fingers.
Claims6
A lead frame of an integrated circuit device package, comprising:
- a die pad having a first side, a second side, a third side, and a fourth side;
- and
- a plurality of lead fingers with a plurality of first quadrant lead fingers arranged about the first and second sides of the die pad in a first quadrant, a plurality of second quadrant lead fingers arranged about the second and third sides of the die pad in a second quadrant, a plurality of third quadrant lead fingers arranged about the third and fourth sides of the die pad in a third quadrant, and a plurality of fourth quadrant lead fingers arranged about the fourth and first sides of the die pad in a fourth quadrant, wherein the die pad is separated from the plurality of lead fingers with essentially no horizontal gap and essentially no horizontal overlap between the first and second sides of the die pad and the plurality of first quadrant lead fingers, the second and third sides of the die pad and the plurality of second quadrant lead fingers, the third and fourth sides of the die pad and the plurality of third quadrant lead fingers, and the fourth and first sides of the die pad and the plurality of fourth quadrant lead fingers.
Dependencies are inferred from the claim text.