Welding alloys, solder paste, solder balls, and welds.

Abstract

The invention relates to a solder alloy, solder paste, solder balls, and solder joints with a low melting point, superior ductility, shear strength, and thermal cycle resistance, further preventing the occurrence of open defects, and in addition, reducing residual voids even at the time of joining in large areas. This solder alloy shall have an alloy composition consisting of, by mass percentage, Bi: 35.0 to 68.0%, Sb: 0.1 to 2.0%, Ni: 0.010 to 0.050%, Ge: 0.007 to 0.090%, with the remainder being Sn. Preferably, the alloy composition shall contain, by mass percentage, at least one of the following elements: Co, Ti, Al, Mn, As, Fe, Pd, Zn, Zr, Pb, In, Ce, P, and Ga: with a total amount less than or equal to 0.1%. Furthermore, this solder alloy can be appropriately used for solder paste, solder balls, and solder joints.

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