Lead frame having a flag with in-plane and out-of-plane mold locking features
View Patent ↗A semiconductor device lead frame having enhanced mold locking features is provided. The lead frame has a flag with bendable edge features along the edge of the flag. Each edge feature is shaped to resist movement against encapsulating mold material in a plane of the edge feature. By bending a portion of the edge feature, improved mold locking of the flag is provided in multiple planes.
1. A packaged electronic device comprising:
a lead frame comprising a flag lying in a first plane defined by a body of the flag, wherein
the flag comprises a plurality of flag edge features located along a perimeter of the flag,
a first flag edge feature is bent near a connection with the flag such that a majority of the first flag edge feature lies in a second plane other than the first plane, and
a second flag edge feature is bent near a connection with the flag such that the majority of the second flag edge feature lies in a third plane other than the first and second planes; and
a cured mold compound encapsulating at least a portion of the flag and the first flag edge feature, wherein
each flag edge feature comprises corresponding first and second ends,
the first end of each flag edge feature is attached to the flag, and
the second end of each flag edge feature is formed to resist movement of the mold compound in a direction of the plane of the flag edge feature where the mold compound comes in contact with the flag edge feature.
2. The packaged electronic device of claim 1 wherein the second end of the first flag edge feature is formed to resist movement of the mold compound by virtue of being wider than the first end of the first flag edge feature.
3. The packaged electronic device of claim 2 wherein the second end of the first flag edge feature is approximately twice as wide as the first edge of the first flag edge feature.
4. The packaged electronic device of claim 1 wherein the lead frame further comprises:
one or more leads arranged around the flag; and
a die, adhesively coupled to a first major surface of the flag along a major surface of the die, and comprising one or more connection pads, wherein
a connection pad of the one or more connection pads is conductively coupled to a lead of the one or more leads.
5. A packaged electronic device comprising:
a lead frame comprising a flag lying in a first plane defined by a body of the flag, wherein
the flag comprises a plurality of flag edge features located along a perimeter of the flag,
a first flag edge feature is bent near a connection with the flag such that a majority of the first flag edge feature lies in a second plane other than the first plane, and
alternating flag edge features of the plurality of flag edge features are bent; and
a cured mold compound encapsulating at least a portion of the flag and the first flag edge feature, wherein
each flag edge feature comprises corresponding first and second ends,
the first end of each flag edge feature is attached to the flag, and
the second end of each flag edge feature is formed to resist movement of the mold compound in a direction of the plane of the flag edge feature where the mold compound comes in contact with the flag edge feature.
6. The packaged electronic device of claim 5 wherein each of the bent flag edge features are bent from the first plane at a same angle.
7. The packaged electronic device of claim 6 wherein the same angle is 90 degrees from the first plane.
8. The packaged electronic device of claim 5 , wherein
a first subset of the bent flag edge features are bent from the first plane at a first angle,
a second subset of the bent flag edge features are bent from the first plane at a second angle, and
the first and second angles are different.
9. The packaged electronic device of claim 1 , wherein
the flag exhibits a first thickness, and
each flag edge feature exhibits a second thickness, wherein the second thickness is less than the first thickness.
10. The packaged electronic device of claim 9 , wherein the first flag edge feature exhibits a length from the first end to the second end that is greater than the first thickness.
11. The packaged electronic device of claim 10 wherein the length of the first flag edge feature is about twice the first thickness.
12. A lead frame for a packaged electronic device, the lead frame comprising:
a flag comprising a plurality of flag edge features located along a perimeter of the flag, wherein
the flag lies in a plane defined by a body of the flag, and
a first flag edge feature of the plurality of flag edge features is bent near a connection with the flag such that a majority of the first flag edge feature lies in a second plane other than the first plane, and
a second flag edge feature of the plurality of flag edge features lies in the plane of the flag; and
leads arranged around the flag.
13. The lead frame of claim 12 wherein the first flag edge feature comprises:
a first end attached to the flag; and
a second end formed to resist movement of a cured mold compound in a direction along the second plane.
14. The lead frame of claim 13 wherein the second end of the first flag edge feature is formed to resist movement of the cured mold compound by virtue of being wider than the first end of the first flag edge feature.
15. The lead frame of claim 14 wherein the second end of the first flag edge feature is approximately twice as wide as the first end of the first flag edge feature.