Leadframe based flash memory cards
View Patent ↗A leadframe design for forming leadframe-based semiconductor packages having curvilinear shapes is disclosed. The leadframes may each include one or more curvilinear slots corresponding to curvilinear edges in the finished and singulated semiconductor package. After encapsulation, the integrated circuit packages on the panel may be singulated by cutting the integrated circuits from the leadframe panel into a plurality of individual integrated circuit packages. The slots in the leadframe advantageously allow each leadframe to be singulated using a saw blade making only straight cuts.
1. A leadframe for a semiconductor package, the leadframe formed from a leadframe panel including a plurality of leadframes, the leadframe comprising:
one or more curvilinear slots formed in the leadframe, the curvilinear slot of the one or more curvilinear slots having a first end lying on a first reference line corresponding to a straight edge along which the leadframe is to be cut upon singulation from the leadframe panel, and the slot having a second end lying on a second reference line corresponding to a straight edge along which the leadframe is to be cut upon singulation from the leadframe panel.
2. A leadframe as recited in claim 1 , wherein the first reference line and the second reference line correspond to the same straight edge along which the leadframe is to be cut upon singulation from the leadframe panel.
3. A leadframe as recited in claim 1 , wherein the first reference line and the second reference line correspond to different straight edges along which the leadframe is to be cut upon singulation from the leadframe panel.
4. A leadframe as recited in claim 1 , wherein the first reference line, the slot and the second reference line together define contiguous edges of the semiconductor package.
5. A leadframe as recited in claim 1 , wherein the slot defines a corner of the semiconductor package.
6. A leadframe as recited in claim 1 , wherein the first reference line is at least substantially orthogonal to the second reference line and the slot defines a rounded corner of the semiconductor package between the first and second reference lines.
7. A leadframe as recited in claim 1 , wherein the slot defines a notch within the outer edge of the semiconductor package.
8. A leadframe as recited in claim 1 , wherein the slot defines recessed portion within the outer edge of the semiconductor package.
9. A leadframe as recited in claim 1 , wherein the leadframe is capable of use in a Transflash flash memory device and the one or more slots define curvilinear edges of the device.
10. A semiconductor package, comprising:
a leadframe including one or more curvilinear slots; and
a semiconductor die affixed to the leadframe;
the semiconductor package formed by the method of:
(a) forming a plurality of leadframes with a plurality of curvilinear slots on a panel;
(b) affixing semiconductor die to the panel;
(c) encapsulating at least portions of the panel in molding compound;
(d) making a plurality of straight line cuts to singulate the semiconductor package, the straight line cuts connecting with the curvilinear slots such that the straight line cuts and the slots define the shape of the outer edges of a singulated semiconductor package.
11. A semiconductor package as recited in claim 10 , wherein the semiconductor package is configured for use as a Transflash flash memory device.
12. A semiconductor package as recited in claim 10 , wherein the semiconductor package is configured for use as a secure digital flash memory device.
13. A semiconductor package as recited in claim 10 further comprising the step of deburring the semiconductor package after the semiconductor package is singulated from the leadframe.