A semiconductor package includes a pad and leads, the pad and leads including a base metal predominantly including copper, a first plated metal layer predominantly including nickel in contact with the base metal, and a second plated metal layer predominantly including silver in contact with the first plated metal layer. The first plated metal layer has a first plated metal layer thickness of 0.1 to 5 microns, and the second plated metal layer has a second plated metal layer thickness of 0.2 to 5 microns. The semiconductor package further includes an adhesion promotion coating predominantly including silver oxide in contact with the second plated metal layer opposite the first plated metal layer, a semiconductor die mounted on the pad, a wire bond extending between the semiconductor die and a lead of the leads, and a mold compound covering the semiconductor die and the wire bond.

A semiconductor package includes a pad and leads, the pad and leads including a base metal predominantly including copper, a first plated metal layer predominantly including nickel in contact with the base metal, and a second plated metal layer predominantly including silver in contact with the first plated metal layer. The first plated metal layer has a first plated metal layer thickness of 0.1 to 5 microns, and the second plated metal layer has a second plated metal layer thickness of 0.2 to 5 microns. The semiconductor package further includes an adhesion promotion coating predominantly including silver oxide in contact with the second plated metal layer opposite the first plated metal layer, a semiconductor die mounted on the pad, a wire bond extending between the semiconductor die and a lead of the leads, and a mold compound covering the semiconductor die and the wire bond.

There is provided a metal-coated Al bonding wire which can provide a sufficient bonding reliability of bonded parts of the bonding wire under a high temperature state where a semiconductor device using the metal-coated Al bonding wire is operated. The bonding wire includes a core wire of Al or Al alloy, and a coating layer of Ag, Au or an alloy containing them formed on the outer periphery of the core wire, and the bonding wire is characterized in that when measuring crystal orientations on a cross-section of the core wire in a direction perpendicular to a wire axis of the bonding wire, a crystal orientation <111> angled at 15 degrees or less to a wire longitudinal direction has a proportion of 30 to 90% among crystal orientations in the wire longitudinal direction. Preferably, the surface roughness of the wire is 2 μm or less in terms of Rz.

There is provided a metal-coated Al bonding wire which can provide a sufficient bonding reliability of bonded parts of the bonding wire under a high temperature state where a semiconductor device using the metal-coated Al bonding wire is operated. The bonding wire includes a core wire of Al or Al alloy, and a coating layer of Ag, Au or an alloy containing them formed on the outer periphery of the core wire, and the bonding wire is characterized in that when measuring crystal orientations on a cross-section of the core wire in a direction perpendicular to a wire axis of the bonding wire, a crystal orientation <111> angled at 15 degrees or less to a wire longitudinal direction has a proportion of 30 to 90% among crystal orientations in the wire longitudinal direction. Preferably, the surface roughness of the wire is 2 μm or less in terms of Rz.

Embodiments include semiconductor packages and methods of forming such packages. A semiconductor package includes a die on a package substrate, an integrated heat spreader (IHS) on the package substrate and above the die, and a solder thermal interface material (STIM) coupling the die to the IHS. The semiconductor package includes a low-temperature solder (LTS) paste comprising an alloy of tin and bismuth (Bi), and the LTS paste on a bottom surface of the package substrate having a ball grid array. The LTS paste may have a weight percentage of Bi greater than 35% and a melting point less than or equal to a melting point of the STIM, where the STIM includes indium. The weight percentage of Bi may be between approximately 35% to 58%. The semiconductor package may include a solder ball coupling the LTS paste on the package substrate to the LTS paste on a second package substrate.

Embodiments include semiconductor packages and methods of forming such packages. A semiconductor package includes a die on a package substrate, an integrated heat spreader (IHS) on the package substrate and above the die, and a solder thermal interface material (STIM) coupling the die to the IHS. The semiconductor package includes a low-temperature solder (LTS) paste comprising an alloy of tin and bismuth (Bi), and the LTS paste on a bottom surface of the package substrate having a ball grid array. The LTS paste may have a weight percentage of Bi greater than 35% and a melting point less than or equal to a melting point of the STIM, where the STIM includes indium. The weight percentage of Bi may be between approximately 35% to 58%. The semiconductor package may include a solder ball coupling the LTS paste on the package substrate to the LTS paste on a second package substrate.

A method for manufacturing a bonding wire includes: putting a surface layer metal of a bonding wire in a crucible having a die cooler provided at the lower part thereof and melting the same; putting a main component metal core of the bonding wire in a core guide located at the upper part of the die cooler of the crucible and heating the core guide to the melting point or below of the metal core; transferring the metal core toward the die cooler so as to allow the molten surface layer metal to be injected to the surface of the metal core; and manufacturing a 50 μm to 350 μm bonding wire from the cast wire precursor by using a drawing die.

A method for manufacturing a bonding wire includes: putting a surface layer metal of a bonding wire in a crucible having a die cooler provided at the lower part thereof and melting the same; putting a main component metal core of the bonding wire in a core guide located at the upper part of the die cooler of the crucible and heating the core guide to the melting point or below of the metal core; transferring the metal core toward the die cooler so as to allow the molten surface layer metal to be injected to the surface of the metal core; and manufacturing a 50 μm to 350 μm bonding wire from the cast wire precursor by using a drawing die.

A process to fabricate ultra-fine grain metal wire, comprising: inserting a plurality of metal strands into a flexible elastic polyurethane sheath having an accommodating slot for each of the strands of metal to form a sheathed strand assembly; equal channel angular pressing (ECAP pressing) the sheathed strand assembly through an ECAP die having a plurality of die channels corresponding to the plurality of metal strands. The process is designed to improve electric conductance and mechanical properties of elongated metal parts and is especially applicable to optimize the conductance and tensile strength of copper cables, wires, strings, and rods.

A process to fabricate ultra-fine grain metal wire, comprising: inserting a plurality of metal strands into a flexible elastic polyurethane sheath having an accommodating slot for each of the strands of metal to form a sheathed strand assembly; equal channel angular pressing (ECAP pressing) the sheathed strand assembly through an ECAP die having a plurality of die channels corresponding to the plurality of metal strands. The process is designed to improve electric conductance and mechanical properties of elongated metal parts and is especially applicable to optimize the conductance and tensile strength of copper cables, wires, strings, and rods.