Method of making an integrated circuit package
View Patent ↗A method of making a package includes providing a metal leadframe having a die pad in a rectangular frame. Tabs extend from the frame toward the die pad. The die pad and tabs have side surfaces with reentrant portions and asperities. A die is attached to the die pad. The die is electrically connected to the tabs. An encapsulant is applied to the upper and side surfaces of the leadframe. Finally, the leadframe is cut in situ so that the die pad and tabs are severed from the frame, the sides of the package are formed, and the package is severed from the leadframe.
1. A method of making an integrated circuit chip package, comprising the steps of:
a) providing a leadframe which includes:
a frame;
a die pad connected to the frame and defining opposed first and second die pad surfaces, and at least one die pad side surface extending between the first and second die pad surfaces;
a plurality of tabs connected to the frame and extending toward the die pad in spaced relation thereto, each of the tabs defining opposed first and second tab surfaces and at one tab side surface extending between the first and second tab surfaces; and
a reentrant portion disposed within at least a portion of the die pad and within each of the tabs;
b) placing an integrated circuit die upon the first die pad surface of the die pad;
c) electrically connecting the integrated circuit die to the first tab surface of at least some of the tabs;
d) applying an encapsulant material to the integrated circuit die, the first die pad surface of the die pad, the first tab surface of each of the tabs, and into the reentrant portions of the die pad and tab side surfaces, without covering the second surface of each of the tabs;
e) hardening the encapsulant material; and
f) plating the second tab surface of each of the tabs.
2. The method of claim 1 further comprising the step of:
g) severing the frame from the die pad and the tabs.
3. The method of claim 1 wherein step (d) comprises applying the encapsulant material such that the second die pad surface of the die pad is not covered by the encapsulant material.
4. The method of claim 3 wherein step (f) further comprises plating the second die pad surface of the die pad.
5. The method of claim 4 wherein step (a) further comprises providing a leadframe having plating applied to the first tab surface of each of the tabs.
6. The method of claim 1 wherein step (a) further comprises providing a leadframe having plating applied to the first tab surface of each of the tabs.
7. The method of claim 6 wherein step (c) comprises electrically connecting the integrated circuit die to the first tab surface of at least some of the tabs through the use of bond wires.
8. The method of claim 1 wherein step (a) comprises providing a leadframe wherein the die pad defines at least four die pad side surfaces, and a reentrant portion is disposed within each of the at least four die pad side surfaces of the die pad.
9. The method of claim 8 wherein step (a) comprises providing a leadframe wherein each of the reentrant portions comprises a peak which extends from a respective one of the die pad and tab side surfaces.
10. The method of claim 8 wherein step (a) comprises providing a leadframe wherein each of the reentrant portions comprises a depression within a respective one of the die pad and tab side surfaces.
11. The method of claim 8 wherein step (a) comprises providing a leadframe wherein each of the reentrant portions comprises a protruding lip which extends along a respective one of the die pad and tab side surfaces.
12. A method of making an integrated circuit chip package, comprising the steps of:
a) providing a leadframe which includes:
a die pad defining opposed first and second die pad surfaces, and at least one die pad side surface extending between the first and second die pad surfaces;
a plurality of tabs extending toward the die pad in spaced relation thereto, each of the tabs defining opposed first and second tab surfaces and at least one tab side surface extending between the first and second tab surfaces;
a locking portion disposed within at least a portion of the die pad and within each of the tabs; and
plating the first tab surface of each of the tabs;
b) placing an integrated circuit die upon the first die pad surface of the die pad;
c) electrically connecting the integrated circuit die to the first tab surface of at least some of the tabs;
d) applying an encapsulant material to the integrated circuit die, the first die pad surface of the die pad, the first tab surface of each of the tabs, and into the locking portions of the die pad and tabs, without covering the second surface of each of the tabs; and
e) hardening the encapsulant material.
13. The method of claim 12 further comprising the step of:
f) plating the second tab surface of each of the tabs.
14. The method of claim 13 further comprising the step of:
g) severing the frame from the die pad and the tabs.
15. The method of claim 13 wherein step (d) comprises applying the encapsulant material such that the second die pad surface of the die pad is not covered by the encapsulant material.
16. The method of claim 15 wherein step (f) further comprises plating the second die pad surface of the die pad.
17. The method of claim 12 wherein step (d) comprises applying the encapsulant material such that the second die pad surface of the die pad is not covered by the encapsulant material.
18. The method of claim 12 wherein step (c) comprises electrically connecting the integrated circuit die to the first tab surface of at least some of the tabs through the use of bond wires.
19. The method of claim 12 wherein step (a) comprises providing a leadframe wherein the die pad defines at least four die pad side surfaces, and a locking portion is disposed within each of the at least four die pad side surfaces of the die pad.
20. A method of making a leadframe for an integrated circuit chip package, comprising the steps of:
a) etching the leadframe form:
a frame;
a die pad connected to the frame and defining opposed first and second die pad surfaces, and at least one die pad side surface extending between the first and second die pad surfaces;
a plurality of tabs connected to the frame and extending toward the die pad in spaced relation thereto, each of the tabs defining opposed first and second tab surfaces and at least one tab side surface extending between the first and second tab surfaces; and
a locking portion disposed within at least a portion of the die pad and within each of the tabs;
b) plating the first tab surface of each of the tabs.