Abstract: A connection formed by a copper wire (112) alloyed with a noble metal in a first concentration bonded to a terminal pad (101) of a semiconductor chip; the end of the wire being covered with a zone (302) including an alloy of copper and the noble metal in a second concentration higher than the first concentration. When the noble metal is gold, the first concentration may range from about 0.5 to 2.0 weight %, and the second concentration from about 1.0 to 5.0 weight %. The zone of the alloy of the second concentration may have a thickness from about 20 to 50 nm.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a contact pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a copper pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a copper pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a copper pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A metal interconnection for two workplaces such as a semiconductor chip and an insulating substrate. The first workpiece (101) has a first contact pad (201) with a gold stud (110); the second workplace (103) is covered with an insulating layer (213) and a window in the layer to a second contact pad (211). The interconnection between the second pad and the gold stud is a 278° C. eutectic structure (111) with about 80 weight percent gold and about 20 weight percent tin. The eutectic structure has a Young's modulus of 59.2 GPa and a lamellar micro-structure of the phases Au5Sn and AuSn. There is substantially no metallic tin at the second contact pad.