Rough leadframe with a nanolayer of silver
AssigneeSTMicroelectronics SDN BHD
InventorYh Heng
Life of this patent
Estimating the term…
Abstract
One or more embodiments are directed to leadframes and leadframe semiconductor packages. One embodiment is directed to copper leadframes with one or more die pads and one more leads with a roughened surface. Covering the roughened surface of the die pad of the leadframe is nanolayer of Silver (Ag). The thickness of the nanolayer preferably has a thickness that corresponds to the roughened surface of the copper leadframe. For instance, in one embodiment, the copper leadframe is roughened to have peaks and valleys that approximately average 10 nanometers and the thickness of the nanolayer is 10 nanometers. Covering a portion of the nanolayer of Ag is a microlayer of Ag, which provides a suitable bonding surface for coupling a semiconductor die to the die pad by an adhesive material.
Claims20
A leadframe semiconductor package comprising:
- a die pad having a roughened surface, a nanolayer of Ag on at least a portion of the roughened surface of the die pad, and a microlayer of Ag on at least a portion of the nanolayer of Ag;
- solder material on the microlayer of Ag;
- a semiconductor chip coupled to the microlayer of Ag by the solder material;
- at least one lead;
- and
- a conductive wire having a first end coupled to a bond pad of the semiconductor chip and a second end coupled to the at least one lead.
A method comprising:
- forming a nanolayer of Ag on a roughened surface of a die pad;
- forming a microlayer of Ag on the nanolayer of Ag;
- and
- using solder material to couple a semiconductor chip to the die pad.
A leadframe semiconductor package comprising:
- a die pad having a roughened surface, a nanolayer of Ag located on the roughened surface;
- solder material on the die pad;
- a semiconductor chip coupled to the die pad by the solder material;
- a plurality of leads having roughened surfaces;
- and
- conductive wires having first ends coupled to bond pads of the semiconductor chip and second ends coupled to the plurality of leads.
Dependencies are inferred from the claim text.