Granted Patent B2

US 9,287,200 · App. 13/928,876 · Granted Mar 15, 2016

Abstract

Claims (30)

1. A packaged semiconductor device, comprising:

a lead frame having a plurality of leads;

a semiconductor die mounted onto the lead frame;

an encapsulant surrounding the semiconductor die, wherein at least a portion of each of the leads is surrounded by the encapsulant, wherein, each lead comprises a knee region of the lead extending external to the encapsulant that is a thin portion and a first thick portion that is surrounded partially by and extends external to the encapsulant and a second thick portion that is a foot portion of the lead, wherein the thin portion is thinner than the first and second thick portions and the thin portion is between the first and second thick portions; and

a bend in a heel/ankle region of the second thick portion adjacent to the foot portion.

2. The packaged semiconductor device of claim 1 , wherein for each lead, the thin portion extends an entire length of the knee region.

3. The packaged semiconductor device of claim 1 , wherein for each lead, a thickness of the thin portion is approximately 50% of a thickness of the first and second thick portions.

4. The packaged semiconductor device of claim 1 , wherein, for each lead, a thickness of the thin portion is in a range of 50-90% of a thickness of the first and second thick portions.

5. A method for forming a packaged semiconductor device, comprising:

attaching a semiconductor die to a lead frame having a plurality of leads to form a lead frame assembly;

encapsulating the lead frame assembly with an encapsulant, wherein the encapsulant surrounds the semiconductor die and at least a portion of each lead of the plurality of leads, wherein each of the plurality of leads comprises a thin portion external to the encapsulant, a first thick portion at one end of the lead that is surrounded partially by and extends from the encapsulant, and a second thick portion at an opposite end of the lead that forms a foot portion, wherein the thin portion is thinner than the first and second thick portions and is between the first and second thick portions; and

forming a bend in a heel/ankle region of the second thick portion, wherein the bend is greater than zero and less than 90 degrees with respect to vertical.

6. The method of claim 5 , further comprising:

after the step of encapsulating, forming the leads.

7. The method of claim 5 , further comprising:

singulating the encapsulated semiconductor die.

8. The method of claim 5 , further comprising:

etching the plurality of leads to form the thin portion of each lead.

9. The method of claim 5 , further comprising:

stamping the lead frame to form the thin portion of each lead.

10. The method of claim 5 , wherein, for each lead, a knee region extends external to the encapsulant, wherein the knee region comprises the thin portion of the lead.

11. The method of claim 10 , wherein, for each lead, the thin portion extends an entire length of the knee region.

12. The method of claim 5 , wherein, for each lead, a thickness of the thin portion is approximately 50% of a thickness of the first and second thick portions.

13. The method of claim 5 , wherein, for each lead, a thickness of the thin portion is in a range of 50 to 90% of a thickness of the first and second thick portions.

14. The method of claim 5 , further comprising:

plating the lead frame prior to attaching the semiconductor die.

15. The method of claim 5 , wherein attaching the semiconductor die comprises:

forming wire bond connections between the semiconductor die and the lead frame.

16. The method of claim 5 , wherein attaching the semiconductor die comprises

forming solder bump connections between the semiconductor die and the lead frame.

Assignments (21)