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.

A palladium coated copper wire for ball bonding includes a core formed of pure copper or copper alloy having a purity of 98% by mass or more, and a palladium draw coated layer coated on the core. The copper wire has a diameter of 10 to 25 m, and the palladium drawn layer contains sulfur, phosphorus, boron or carbon.

A palladium coated copper wire for ball bonding includes a core formed of pure copper or copper alloy having a purity of 98% by mass or more, and a palladium draw coated layer coated on the core. The copper wire has a diameter of 10 to 25 m, and the palladium drawn layer contains sulfur, phosphorus, boron or carbon.

A precious metal paste which does not cause contamination of a member, which can be uniformly coated to a member to be bonded, and which is in good condition after bonding is provided. The present invention relates to a precious metal paste for bonding a semiconductor element, of the paste including a precious metal powder and an organic solvent, in which the precious metal powder has a purity of 99.9 mass % or more and an average particle diameter of 0.1 to 0.5 m, the organic solvent has a boiling point of 200 to 350 C., and a thixotropy index (TI) value calculated from a measurement value of a viscosity at a shear rate of 4/s with respect to a viscosity at a shear rate of 40/s at 23 C. by means of a rotational viscometer is 6.0 or more.

A precious metal paste which does not cause contamination of a member, which can be uniformly coated to a member to be bonded, and which is in good condition after bonding is provided. The present invention relates to a precious metal paste for bonding a semiconductor element, of the paste including a precious metal powder and an organic solvent, in which the precious metal powder has a purity of 99.9 mass % or more and an average particle diameter of 0.1 to 0.5 m, the organic solvent has a boiling point of 200 to 350 C., and a thixotropy index (TI) value calculated from a measurement value of a viscosity at a shear rate of 4/s with respect to a viscosity at a shear rate of 40/s at 23 C. by means of a rotational viscometer is 6.0 or more.

There is provided a copper bonding wire having an improved storage life in the atmosphere. There is specifically provided a copper bonding wire for semiconductor devices characterized in that a density of crystal grain boundary on a surface of the wire is 0.6 (m/m.sup.2) or more and 1.6 (m/m.sup.2) or less.