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 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.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer on a surface of the Cu alloy core material, and contains Ga and Ge of 0.011 to 1.2% by mass in total, which is able to increase bonding longevity of the ball bonded part in the high-temperature, high-humidity environment, and thus to improve the bonding reliability. The thickness of the Pd coating layer is preferably 0.015 to 0.150 m. When the bonding wire further contains one or more elements of Ni, Ir, and Pt in an amount, for each element, of 0.011 to 1.2% by mass, it is able to improve the reliability of the ball bonded part in a high-temperature environment at 175 C. or more. When an alloy skin layer containing Au and Pd is further formed on a surface of the Pd coating layer, wedge bondability improves.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer on a surface of the Cu alloy core material, and contains Ga and Ge of 0.011 to 1.2% by mass in total, which is able to increase bonding longevity of the ball bonded part in the high-temperature, high-humidity environment, and thus to improve the bonding reliability. The thickness of the Pd coating layer is preferably 0.015 to 0.150 m. When the bonding wire further contains one or more elements of Ni, Ir, and Pt in an amount, for each element, of 0.011 to 1.2% by mass, it is able to improve the reliability of the ball bonded part in a high-temperature environment at 175 C. or more. When an alloy skin layer containing Au and Pd is further formed on a surface of the Pd coating layer, wedge bondability improves.

A bonding wire for a semiconductor device including a coating layer having Pd as a main component on the surface of a Cu alloy core material and a 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 a metallic element of Group 10 of the Periodic Table of Elements in a total amount of 0.1 to 3.0% by mass, thereby achieving improvement in 2nd bondability and excellent ball bondability in a high-humidity heating condition. Furthermore, a maximum concentration of Au in the skin alloy layer is preferably 15 at % to 75 at %.

The present invention provides a bonding wire which can satisfy bonding reliability, spring performance, and chip damage performance required in high-density packaging. A bonding wire contains one or more of In, Ga, and Cd for a total of 0.05 to 5 at %, and a balance being made up of Ag and incidental impurities.

Bonding wire for semiconductor device use where both leaning failures and spring failures are suppressed by (1) in a cross-section containing the wire center and parallel to the wire longitudinal direction (wire center cross-section), there are no crystal grains with a ratio a/b of a long axis a and a short axis b of 10 or more and with an area of 15 m.sup.2 or more (fiber texture), (2) when measuring a crystal direction in the wire longitudinal direction in the wire center cross-section, the ratio of crystal direction <100> with an angle difference with respect to the wire longitudinal direction of 15 or less is, by area ratio, 10% to less than 50%, and (3) when measuring a crystal direction in the wire longitudinal direction at the wire surface, the ratio of crystal direction <100> with an angle difference with respect to the wire longitudinal direction of 15 or less is, by area ratio, 70% or more. During the drawing step, a drawing operation with a rate of reduction of area of 15.5% or more is performed at least once. The final heat treatment temperature and the pre-final heat treatment temperature are made predetermined ranges.