Provided are a Cu ball, an OSP-treated Cu ball, a Cu core ball, a solder joint, solder paste, and formed solder, which realize high sphericity and low hardness and in which discoloration is suppressed. An electronic component is configured by joining a solder bump of a semiconductor chip and an electrode of a printed circuit board with solder pastes The solder bump formed by joining a Cu ball to an electrode of the semiconductor chip. The Cu ball has a purity of 99.995% by mass or more and 99.9995% by mass or less, a total content of at least one element selected from Fe, Ag, and Ni of 5.0 ppm by mass or more and 50.0 ppm by mass or less, a content of S of 1.0 ppm by mass or less, and a content of P of less than 3.0 ppm by mass.
展开▼
