Minute copper balls and a method for their manufacture
AssigneeSenju Metal Industry Co., Ltd.
InventorsRyoichi Kurata, Hoshiro Takahashi
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Abstract
Minute copper balls having a high sphericity which are suitable for use as the cores of copper core solder balls are manufactured by heating small pieces comprising an alloy of 0.5-40 wt % of Zn and a remainder of Cu to at least the melting point of Cu without the pieces contacting each other to give them a spherical shape and cooling the resulting spheres to form solid balls. The minute copper balls which are obtained comprises 0.01-0.5 wt % of Zn and a remainder of Cu and have a spherical shape with a diameter in the range of 50-1000 μm.
Claims11
Minute copper balls having a composition consisting essentially of 0.01-0.5 wt % of Zn and a remainder of Cu and having a spherical shape with a diameter in the range of 50-1000 μm.
A method of manufacturing minute copper balls comprising heating small pieces comprising a Cu—Zn alloy consisting essentially of 0.5-40 wt % of Zn and a remainder of Cu to a temperature which is at least the melting point of copper without contacting the pieces with each other to form the pieces into spheres with a Zn content of 0.01-0.5 wt %, and then cooling the spheres to form solid balls.
Dependencies are inferred from the claim text.