A stack package and a method of manufacturing the stack package are provided. The method includes: attaching a first semiconductor device onto a first surface of a first package substrate; attaching a molding resin material layer onto a first surface of a second package substrate; arranging the first surface of the first package substrate and the first surface of the second package substrate to face each other; compressing the first package substrate and the second package substrate while reflowing the molding resin material layer; and hardening the reflowed molding resin material layer.

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.