Lead frame having increased stability due to reinforced die pads and packaging method using such lead frame
View Patent ↗There is provided a lead frame and a packaging method. The lead frame comprises a first plurality of die pads, a second plurality of leads extending from the first plurality of die pads, and a third plurality of tie elements, each of which connects one of the first plurality of die pads to another.
1. A lead frame, comprising:
a first plurality of die pads;
a second plurality of leads extending from the first plurality of die pads;
a third plurality of tie elements, each of which connects one die pad of the first plurality of die pads to another die pad of the first plurality of die pads; and
a strip element connected to the second plurality of leads;
wherein each of the first plurality of die pads comprises a tab portion at an end opposite the second plurality of leads;
wherein each of the third plurality of tie elements connects one die pad to another at respective tab portions.
2. The lead frame of claim 1 , wherein each of the third plurality of tie elements connects two adjacent die pads.
3. The lead frame of claim 1 , wherein each of the third plurality of tie elements is integral with the two die pads connected thereto.
4. A lead frame for discrete package, comprising the lead frame of any of claim 1 .
5. The lead frame of claim 1 , wherein at least one tie element of the third plurality of tie elements is shaped as a strip.
6. The lead frame of claim 1 , wherein at least one tie element of the third plurality of tie elements is shaped as a polygon.
7. The lead frame of claim 1 , wherein the first plurality of die pads, the second plurality of leads and the third plurality of tie elements are integrally formed.
8. A method, comprising:
forming a lead frame having:
a first plurality of die pads,
a second plurality of leads extending from the first plurality of die pads,
a third plurality of tie elements, each of which connects one of the first plurality of die pads to another, and
a strip element connected to the second plurality of leads;
attaching a first plurality of dice to the first plurality of die pads respectively;
attaching at least a wire bond between each of the first plurality of dice and the corresponding die pad respectively;
molding the first plurality of dice; and
cutting off the third plurality of tie elements;
wherein each of the first plurality of die pads comprises a tab portion at an end opposite the second plurality of leads;
wherein each of the third plurality of tie elements connects a die pad from the first plurality of die pads to another die pad from the first plurality of die pads at respective tab portions.
9. The method of claim 8 , wherein the first plurality of dice are molded with encapsulation material.
10. The method of claim 8 , wherein the encapsulation material comprises resin or plastic.
11. The method of claim 8 , wherein the strip element facilitates performing operations on the lead frame.
12. A lead frame, comprising:
a plurality of die pads;
a plurality of leads extending from the first plurality of die pads;
a plurality of tie elements, wherein at least one tie element of the plurality of tie elements connects a die pad of the plurality of die pads to another die pad of the plurality of die pads; and
a strip element connected to the plurality of leads;
wherein each of the plurality of die pads comprises a tab portion at an end opposite the plurality of leads;
wherein each of the plurality of tie elements connects a die pad from the plurality of die pads to another die pad from the plurality of die pads at respective tab portions.