Semiconductor leadframes plated with thick nickel, minimum palladium, and pure tin
AssigneeTexas Instruments Incorporated
InventorsDonald C. Abbott, Douglas W. Romm
Life of this patent
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Abstract
A leadframe for use with integrated circuit chips comprising a base metal having a plated layer of nickel fully covering the base metal; a plated layer of pure tin on the nickel layer, selectively covering areas of the leadframe intended for attachment to other parts; and a plated layer of palladium on said nickel layer, selectively covering areas of said Leadframe intended for bonding wire attachment.
Claims8
A method for forming a leadframe for use in the assembly of integrated circuit devices, comprising:
- providing a base metal structure;
- forming a nickel layer on the metal structure;
- forming a matte, coarse grain, tin solder layer on the nickel layer selectively, covering an area of said leadframe for attaching a integrated circuit chip;
- and
- forming a palladium or silver layer selectively, covering an area of said leadframe suitable for attaching a bonding wire.
A method for forming a leadframe for use with integrated circuit chips comprising:
- providing a base metal structure having a plated layer of nickel fully covering said base metal;
- forming a layer of matte, coarse grain, pure tin on said nickel layer selectively, covering
- an area of said leadframe suitable for attaching a circuit chip;
- and
- forming a layer of palladium or silver on said nickel layer selectively, covering an area of said leadframe suitable for attaching a bonding wire.
A method for forming a semiconductor device comprising:
- providing a leadframe including a chip-mount pad and a lead segment having a first end
- near said mount pad and a second end remote from said mount pad;
- forming a nickel layer over said leadframe;
- forming a layer of palladium on said nickel layer selectively, covering said first end of said lead segment;
- attaching an integrated circuit chip to said mount pad;
- and
- applying a layer of matte, coarse grain, pure tin solder selectively, covering said second end of said lead segment.
Dependencies are inferred from the claim text.