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.

Produced is a metal ball which suppresses an emitted dose. Contained are the steps of melting a pure metal by heating the pure metal at a temperature which is higher than a boiling point of an impurity to be removed, higher than a melting point of the pure metal, and lower than a boiling point of the pure metal, the pure metal containing a U content of 5 ppb or less, a Th content of 5 ppb or less, purity of 99.9% or more and 99.995% or less, and a Pb or Bi content or a total content of Pb and Bi of 1 ppm or more, and the pure metal having the boiling point higher than the boiling point at atmospheric pressure of the impurity to be removed; and sphering the molten pure metal in a ball.

Produced is a metal ball which suppresses an emitted dose. Contained are the steps of melting a pure metal by heating the pure metal at a temperature which is higher than a boiling point of an impurity to be removed, higher than a melting point of the pure metal, and lower than a boiling point of the pure metal, the pure metal containing a U content of 5 ppb or less, a Th content of 5 ppb or less, purity of 99.9% or more and 99.995% or less, and a Pb or Bi content or a total content of Pb and Bi of 1 ppm or more, and the pure metal having the boiling point higher than the boiling point at atmospheric pressure of the impurity to be removed; and sphering the molten pure metal in a ball.

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 %.

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 %.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer formed on a surface thereof, and the boding wire contains one or more elements of As, Te, Sn, Sb, Bi and Se in a total amount of 0.1 to 100 ppm by mass. The bonding longevity of a ball bonded part can increase in a high-temperature and high-humidity environment, improving the bonding reliability. When the Cu alloy core material further contains one or more of Ni, Zn, Rh, In, Ir, Pt, Ga and Ge in an amount, for each, of 0.011 to 1.2% by mass, it is able to increase the reliability of a ball bonded part in a high-temperature environment of 170 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 formed on a surface thereof, and the boding wire contains one or more elements of As, Te, Sn, Sb, Bi and Se in a total amount of 0.1 to 100 ppm by mass. The bonding longevity of a ball bonded part can increase in a high-temperature and high-humidity environment, improving the bonding reliability. When the Cu alloy core material further contains one or more of Ni, Zn, Rh, In, Ir, Pt, Ga and Ge in an amount, for each, of 0.011 to 1.2% by mass, it is able to increase the reliability of a ball bonded part in a high-temperature environment of 170 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.

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.