Etched surface mount islands in a leadframe package
AssigneeSanDisk Technologies LLC
InventorsSuresh Upadhyayula, Bonnie Ming-Yan Chan, Shih-Ping Fan-chiang, Hem Takiar
Life of this patent
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Abstract
A method of fabricating a leadframe-based semiconductor package, and a semiconductor package formed thereby, are disclosed. The semiconductor package includes a leadframe and one or more semiconductor die affixed to a die paddle of the leadframe. The leadframe is formed with a plurality of electrical terminals that get surface mounted to a host PCB. The leadframe further includes one or more extended leads, at least one of which includes an electrically conductive island which gets surface mounted to the host PCB with the electrical terminals. The islands effectively increase the number terminals within the package without adding footprint to the package.
Claims28
A method of fabricating a leadframe package including a leadframe and a semiconductor die, the leadframe including a die paddle supporting the semiconductor die and the semiconductor die including die bond pads along at least two sides, the method comprising the steps of:
- (a) defining a plurality of electrical terminals around a periphery of the leadframe, the electrical terminals being exposed at a bottom surface of the leadframe package for connection to a host printed circuit board;
- (b) defining one or more electrically conductive islands on the leadframe at least in part between the electrical terminals and the die paddle and formed at least in part by half-etching an area adjacent the islands on the leadframe, the islands being exposed at the bottom surface of the leadframe package for connection to the host printed circuit board, and one island of the one or more electrically conductive islands connected to at least one other terminal of the plurality of electrical terminals or another island of the one or more electrically conductive islands;
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- (c) wirebonding the die bond pads to the electrical terminals defined in said step (a) and the one or more electrically conductive islands defined in said step (b).
A method of fabricating a leadframe package including a leadframe and a semiconductor die, the leadframe including a die paddle supporting the semiconductor die and the semiconductor die including die bond pads along at least two sides, the method comprising the steps of:
- (d) defining a plurality of electrical terminals around a periphery of the leadframe, the electrical terminals being exposed at a bottom surface of the leadframe package for connection to a host printed circuit board;
- (e) defining an electrical lead extending into a space between the electrical terminals and the die paddle;
- (f) defining a plurality of electrically conductive islands on the electrical lead at least in part by half-etching an area on the electrical lead, the islands being exposed at the bottom surface of the leadframe package for connection to the host printed circuit board;
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- (g) wirebonding the die bond pads to the electrical terminals defined in said step (a) and the one or more electrically conductive islands defined in said step (c).
A method of fabricating a leadframe package including a leadframe and a semiconductor die, the leadframe including a die paddle supporting the semiconductor die, the die paddle having a pair of tie bars at first and third diametrically opposed corners for supporting the die paddle in the leadframe, and the semiconductor die including die bond pads along at least two sides, the method comprising the steps of:
- (h) defining a plurality of electrical terminals around a periphery of the leadframe, the electrical terminals being exposed at a bottom surface of the leadframe package for connection to a host printed circuit board;
- (i) defining a first electrical lead coupled to a first electrical terminal of the plurality of electrical terminals, the first electrical lead extending into a space between the electrical terminals and the die paddle;
- (j) defining a first electrically conductive island along the first electrical lead at least in part by half-etching the first electrical lead, the first island being exposed at the bottom surface of the leadframe package for connection to the host printed circuit board;
- (k) defining a second electrical lead extending from one of the second and fourth corners of the leadframe, the second electrical lead extending into a space between the electrical terminals and the die paddle;
- and
- (e) defining a second electrically conductive island along the second electrical lead at least in part by half-etching the second electrical lead, the second island being exposed at the bottom surface of the leadframe package for connection to the host printed circuit board;
- (f) wirebonding the die bond pads to the electrical terminals defined in said step (a) and the first and second electrically conductive islands defined in said steps (c) and (e).
Dependencies are inferred from the claim text.