| 摘要 |
PROBLEM TO BE SOLVED: To obtain small gold balls for bump which have such good deformability and sufficient joining strength that can cope with a reduction in pitch, by constituting the gold balls containing one or more kinds of metals selected from among Cu, Pd, and Pt at specific percents by weight and inevitable impurities. SOLUTION: A gold alloy ingot is obtained by mixing 0.03-5 wt.% of one or more kinds of metals selected from among Cu, Pd, and Pt in electrolytic gold with purity of about 99.999% containing inevitable impurities by the high- frequency vacuum melting method and rolled to a ribbon-like shape. A metallic foil thus obtained is cut into small pieces, and small gold balls 1 are formed by melting and solidifying the small pieces by letting the pieces fall in a heated furnace. The balls 1 are used as bumps and sucked to a substrate 4 for arranging bumps by vacuum. Then, the A1 electrodes 2 of a semiconductor chip 3 are placed aligned on the balls 1 and joined to the balls 1 by pressing the electrodes 2 against the balls 1 by means of a bonding tool. |
