Abstract: A lead-free solder composition includes: 3 wt % to 5 wt % of Ag, 0.2 wt % to 0.8 wt % of Cu, 1 wt % to 7 wt % of Bi, 0.005 wt % to 0.06 wt % of Ni, 0.005 wt % to 0.02 wt % of Ge, and the balance being Sn based on 100 wt % of the lead-free solder composition.

Abstract: A silver-free and lead-free solder composition includes: 2 wt % to 8 wt % of Bi, 0.1 wt % to 1.0 wt % of Cu, 0.01 wt % to 0.2 wt % of at least one of Ni, Fe, and Co, and the balance of Sn based on 100 wt % of the silver-free and lead-free solder composition.

Abstract: A method of forming metal spheres includes ejecting a precisely measured droplet of molten metal from a molten metal mass, buffering the molten metal droplet to reduce the internal kinetic energy of the droplet without solidifying the droplet and cooling the buffered droplet until the droplet solidifies in the form of a metal sphere. An apparatus for fabricating metal spheres includes a droplet generator that generates a droplet from a molten metal mass, a buffering chamber that receives the droplet from the droplet generator, and diminishes internal kinetic energy of the droplet without solidifying the droplet, and a cooling drum that receives the droplet from the buffering chamber, and cools the droplet to the extent that the droplet solidifies into a metal sphere. The apparatus may further include a collector arrangement that receives the metal spheres from the cooling drum and makes the metal sphere available for collection.

Abstract: A method of forming metal spheres includes ejecting a precisely measured droplet of molten metal from a molten metal mass, buffering the molten metal droplet to reduce the internal kinetic energy of the droplet without solidifying the droplet and cooling the buffered droplet until the droplet solidifies in the form of a metal sphere. An apparatus for fabricating metal spheres includes a droplet generator that generates a droplet from a molten metal mass, a buffering chamber that receives the droplet from the droplet generator, and diminishes internal kinetic energy of the droplet without solidifying the droplet, and a cooling drum that receives the droplet from the buffering chamber, and cools the droplet to the extent that the droplet solidifies into a metal sphere. The apparatus may further include a collector arrangement that receives the metal spheres from the cooling drum and makes the metal sphere available for collection.

Abstract: A method of forming metal spheres includes ejecting a precisely measured droplet of molten metal from a molten metal mass, buffering the molten metal droplet to reduce the internal kinetic energy of the droplet without solidifying the droplet and cooling the buffered droplet until the droplet solidifies in the form of a metal sphere. An apparatus for fabricating metal spheres includes a droplet generator that generates a droplet from a molten metal mass, a buffering chamber that receives the droplet from the droplet generator, and diminishes internal kinetic energy of the droplet without solidifying the droplet, and a cooling drum that receives the droplet from the buffering chamber, and cools the droplet to the extent that the droplet solidifies into a metal sphere. The apparatus may further include a collector arrangement that receives the metal spheres from the cooling drum and makes the metal sphere available for collection.

Abstract: An apparatus for forming metal spheres includes a droplet generator, a buffering chamber, and a cooling drum. The droplet generator generates a droplet from a molten metal mass. The buffering chamber receives the droplet from the droplet generator, and diminishes internal kinetic energy of the droplet without solidifying the droplet. The cooling drum receives the droplet from the buffering chamber, and cools the droplet to the extent that the droplet solidifies into a metal sphere. The apparatus can further include a collector arrangement that receives the metal spheres from the cooling drum and makes the metal spheres available for collection.