Patent ID: 8408448
Filing Date: 2013-04-02
Classification: B23K

Abstract:
1. A method for forming spherical metal balls comprising: filling cavities in a mold with molten metal; cooling said molten metal to a solid in said cavities in said mold; selecting a plate having cavities having openings facing openings of said cavities in said mold; said cavities in said plate larger than said corresponding facing cavities in said mold; filling said cavities in said plate with a liquid for removing metal oxides; placing said cavity openings of said mold facing downwards and above said corresponding cavity openings facing upwards in said plate; heating said mold and plate above a metal melting temperature to reflow said metal whereby said metal is released from said cavity in said mold and passes into said liquid in said corresponding facing cavity in said plate, said metal being unconstrained in said liquid forming spherical metal balls due to metal surface tension; and cooling said spherical metal balls below said melting temperature to form solid spherical metal balls.