Leadframe based multi terminal IC package
A semiconductor package comprises a die attach pad and a support member at least partially circumscribing it. Several sets of contact pads are attached to the support member. The support member is able to be etched away thereby electrically isolating the contact pads. A method for making a leadframe and subsequently a semiconductor package comprises partially etching desired features into a copper substrate, and then through etching the substrate to form the support member and several sets of contact pads. Die attach, wirebonding and molding follow. The support member is etched away, electrically isolating the contact pads and leaving a groove in the bottom of the package. The groove is able to be filled with epoxy or mold compound.
1. A semiconductor package comprising:
a. a die attach pad;
b. at least one semiconductor die coupled with the die attach pad;
c. a first set of contact pads surrounding the die attach pad;
d. a groove at least partially circumscribing the first set of contact pads;
e. a second set of contact pads surrounding the groove;
f. a third set of contact pads between the first set of contact pads and the die attach pad, wherein each contact pad of the third set of contact pads includes a portion of an anchor bar abutting the groove;
g. a plurality of bondwires for electrically coupling the die to at least one contact pad;
h. an encapsulant encasing the at least one semiconductor die and the plurality of bondwires; and
i. a filler substance separate from the encapsulant, the filler substance disposed within the groove.
2. The semiconductor package of claim 1 , wherein a bottom surface of the semiconductor package is substantially planar except for the groove.
3. The semiconductor package of claim 1 , wherein a bottom surface of the die attach pad and bottom surfaces of the contact pads define the substantially planar bottom surface of the package.
4. The semiconductor package of claim 1 , wherein the groove comprises an epoxy filler.
5. The semiconductor package of claim 1 , wherein the second set of contact pads does not contact an edge of the groove.
6. The semiconductor package of claim 1 , wherein the first set of contact pads does not contact an edge of the groove.
7. The semiconductor package of claim 1 , further comprising a fourth set of contact pads surrounding the second set of contact pads.
8. The semiconductor package of claim 1 , wherein the first set of contact pads and the second set of contact pads are staggered.
9. The semiconductor package of claim 1 , wherein each contact pad of the first set of contact pads includes a first member extending away from the die attach pad, and wherein the each contact pad of the second set of contact pads includes a second member extending towards the die attach pad.
10. The semiconductor package of claim 1 , wherein the filler substance disposed within the groove is flush with a bottom surface of the encapsulant.
11. The semiconductor package of claim 7 , wherein each contact pad of the fourth set of contact pads includes a portion of an anchor bar abutting the groove.