There is provided a bonding wire for a semiconductor device including a coating layer having Pd as a main component on a surface of a Cu alloy core material and a skin alloy layer containing Au and Pd on a surface of the coating layer, the bonding wire further improving 2nd bondability on a Pd-plated lead frame and achieving excellent ball bondability even in a high-humidity heating condition. The bonding wire for a semiconductor device including the coating layer having Pd as a main component on the surface of the Cu alloy core material and the skin alloy layer containing Au and Pd on the surface of the coating layer has a Cu concentration of 1 to 10 at % at an outermost surface thereof and has the core material containing either or both of Pd and Pt in a total amount of 0.1 to 3.0% by mass, thereby achieving improvement in the 2nd bondability and excellent ball bondability in the high-humidity heating condition. Furthermore, a maximum concentration of Au in the skin alloy layer is preferably 15 at % to 75 at %.

A micro-coaxial wire has an overall diameter in a range of 0.1 m-550 m, a conductive core of the wire has a cross-sectional diameter in a range of 0.05 m-304 m, an insulator is disposed on the conductive core with thickness in a range of 0.005 m-180 m, and a conductive shield layer is disposed on the insulator with thickness in a range of 0.009 m-99 m.

A wire comprising a wire core with a surface, the wire core having a coating layer superimposed on its surface, wherein the wire core itself is a silver-based wire core, wherein the coating layer is a double-layer comprised of a 1 to 100 nm thick inner layer of nickel or palladium and an adjacent 1 to 250 nm thick outer layer of gold, characterized in that the wire exhibits a total carbon content of 40 wt.-ppm.

There is provided a novel Cu bonding wire that achieves a favorable FAB shape and achieve a favorable bond reliability of the 2nd bonding part even in a rigorous high-temperature environment. The bonding wire for semiconductor devices includes a core material of Cu or Cu alloy, and a coating layer having a total concentration of Pd and Ni of 90 atomic % or more formed on a surface of the core material. The bonding wire is characterized in that: in a concentration profile in a depth direction of the wire obtained by performing measurement using Auger electron spectroscopy (AES) so that the number of measurement points in the depth direction is 50 or more for the coating layer, a thickness of the coating layer is 10 nm or more and 130 nm or less, an average value X is 0.2 or more and 35.0 or less where X is defined as an average value of a ratio of a Pd concentration C.sub.Pd (atomic %) to an Ni concentration C.sub.Ni (atomic %), C.sub.Pd/C.sub.Ni, for all measurement points in the coating layer, the total number of measurement points in the coating layer whose absolute deviation from the average value X is 0.3X or less is 50% or more relative to the total number of measurement points in the coating layer, and the bonding wire satisfies at least one of following conditions (i) and (ii): (i) a concentration of In relative to the entire wire is 1 ppm by mass or more and 100 ppm by mass or less; and (ii) a concentration of Ag relative to the entire wire is 1 ppm by mass or more and 500 ppm by mass or less.

There is provided a bonding wire for a semiconductor device including a coating layer having Pd as a main component on a surface of a Cu alloy core material and a skin alloy layer containing Au and Pd on a surface of the coating layer, the bonding wire further improving 2nd bondability on a Pd-plated lead frame and achieving excellent ball bondability even in a high-humidity heating condition. The bonding wire for a semiconductor device including the coating layer having Pd as a main component on the surface of the Cu alloy core material and the skin alloy layer containing Au and Pd on the surface of the coating layer has a Cu concentration of 1 to 10 at % at an outermost surface thereof and has the core material containing either or both of Pd and Pt in a total amount of 0.1 to 3.0% by mass, thereby achieving improvement in the 2nd bondability and excellent ball bondability in the high-humidity heating condition. Furthermore, a maximum concentration of Au in the skin alloy layer is preferably 15 at % to 75 at %.

A light-emitting device includes a light emitting element having a pad electrode, and a metal member connected to the pad electrode via a wire. The wire has a layered structure including at least a core material containing copper as a main component, an intermediate layer containing palladium as a main component, and a surface layer containing silver as a main component. The intermediate layer is art raged between the core material and the surface layer.

A semiconductor device 10 includes a pair of electrodes 16 and a conductive connection member 21 electrically bonded to the pair of electrodes 16. At least a portion of a perimeter of a bonding surface 24 of at least one of the pair of electrodes 16 and the conductive connection member 21 includes an electromigration reducing area 22.

A wire comprising a wire core with a surface, the wire core having a coating layer superimposed on its surface, wherein the wire core includes: (a) pure silver consisting of silver and further components; or (b) doped silver consisting of silver, at least one doping element, and further components; or (c) a silver alloy consisting of silver, palladium and further components; or (d) a silver alloy consisting of silver, palladium, gold, and further components; or (e) a doped silver alloy consisting of silver, palladium, gold, at least one doping element, and further components, wherein the individual amount of any further component is less than 30 wt.-ppm and the individual amount of any doping element is at least 30 wt.-ppm, and the coating layer is a single-layer of gold or palladium or a double-layer comprised of an inner layer of nickel or palladium and an adjacent outer layer of gold.

A bonding wire includes a Cu alloy core material, and a Pd coating layer formed on the Cu alloy core material. The bonding wire contains at least one element selected from Ni, Zn, Rh, In, Ir, and Pt. A concentration of the elements in total relative to the entire wire is 0.03% by mass or more and 2% by mass or less. When measuring crystal orientations on a cross-section of the core material in a direction perpendicular to a wire axis of the bonding wire, a crystal orientation <100> angled at 15 degrees or less to a wire axis direction has a proportion of 50% or more among crystal orientations in the wire axis direction. An average crystal grain size in the cross-section of the core material in the direction perpendicular to the wire axis of the bonding wire is 0.9 m or more and 1.3 m or less.

The present invention provides a ball forming method for forming a ball portion at a tip of a bonding wire which includes a core material mainly composed of Cu, and a coating layer mainly composed of Pd and formed over a surface of the core material, wherein the ball portion is formed in non-oxidizing atmosphere gas including hydrocarbon which is gas at room temperature and atmospheric pressure, the method being capable of improving Pd coverage on a ball surface in forming a ball at a tip of the Pd-coated Cu bonding wire.