Auxiliary leadframe member for stabilizing the bond wire process
A semiconductor package comprises a die attach pad and an auxiliary support member at least partially circumscribing the die attach pad. A set of contact leads is formed extending outward from the die attach pad. A first set of contact pads is formed on the bottom surface of the distal ends of the contact leads. An optional second set of contact pads is formed at the bottom surface of the proximal end. The auxiliary support member prevents damage to the contact leads and prevents the leads from bending during the manufacturing process.
1. A semiconductor package comprising:
a. a die attach pad;
b. at least one semiconductor die coupled with the die attach pad;
c. a groove grooved ring at least partially circumscribing the die attach pad and an encapsulant;
d. a set of contact leads extending outwards from the die attach pad, each contact lead having a proximal end to the die attach pad and a distal end, wherein the proximal end is positioned over and exposed by the groove; and
e. a plurality of bond wires for electrically coupling the die to at least one contact pad.
2. The semiconductor package of claim 1 wherein each contact lead comprises a full thickness portion at the distal end.
3. The semiconductor package of claim 1 wherein each contact lead comprises a partial thickness portion at the proximal end.
4. The semiconductor package of claim 1 wherein each contact lead comprises a contact pad on a bottom surface of the distal end.
5. The semiconductor package of claim 4 wherein each contact lead comprises a contact pad on a bottom surface of the proximal end.
6. The semiconductor package of claim 1 wherein a bottom surface of the semiconductor package is substantially planar.
7. The semiconductor package of claim 6 wherein a bottom surface of the die attach pad and bottom surfaces of the contact leads define the substantially planar bottom surface of the package.
8. The semiconductor package of claim 1 wherein the grooved ring is filled by a discrete epoxy filler.
9. The semiconductor package of claim 1 further comprising a mold compound at least partially encasing the at least one semiconductor die, the set of contact leads and the plurality of bond wires, wherein the groove is formed in the mold compound and is positioned outside a perimeter of the die attach pad.
10. A method of making a semiconductor package comprising:
a. etching a through pattern in a metal substrate, thereby forming a die attach pad, a set of contact leads having a first set of contact pads surrounding the die attach pad and an auxiliary support member at least partially circumscribing the die attach pad, wherein each contact lead has a protruding portion at a proximal end to the die attach pad, the protruding portion having a first contact pad, and a distal end of the contact lead having a second contact pad, further wherein the protruding portion of each contact lead is positioned over and supported by the auxiliary support member;
b. mounting at least one semiconductor die on the die attach pad;
c. mounting bond wires for electrically coupling the at least one semiconductor die to at least one first contact pad;
d. at least partially encasing the semiconductor die, bond wires, auxiliary support member and contact leads in a mold compound while leaving one surface of the metal substrate exposed;
e. etching away at least a portion of the auxiliary support member thereby electrically isolating the contact leads from each other.
11. The method of claim 10 wherein forming the set of contact leads comprises forming a full thickness portion at the distal end such that the distal end is self-supporting.
12. The method of claim 10 wherein etching away at least the portion of the auxiliary support member comprises removing a portion of the auxiliary support member positioned between adjacent contact leads while leaving intact a portion of the auxiliary support member positioned underneath the proximal end of each contact lead.
13. The method of claim 12 wherein etching away at least the portion of the auxiliary support member forms a second set of contact pads such that the portion of the auxiliary support member positioned underneath the proximal end of each contact lead has a third contact pad.
14. The method of claim 10 further comprising filling the etched portion of the auxiliary support member with an epoxy.
15. The method of claim 14 wherein filling the etched portion of the auxiliary support member with epoxy comprises a stencil step.
16. The method of claim 14 wherein filling the etched portion of the auxiliary support member with epoxy comprises a nozzle filling step.
17. The method of claim 10 wherein etching away at least the portion of the auxiliary support member forms a groove at least partially circumscribing the die attach pad.