The present invention provides a ball forming method for forming a ball portion at a tip of a bonding wire which includes a core material mainly composed of Cu, and a coating layer mainly composed of Pd and formed over a surface of the core material, wherein the ball portion is formed in non-oxidizing atmosphere gas including hydrocarbon which is gas at room temperature and atmospheric pressure, the method being capable of improving Pd coverage on a ball surface in forming a ball at a tip of the Pd-coated Cu bonding wire.

The present invention provides a ball forming method for forming a ball portion at a tip of a bonding wire which includes a core material mainly composed of Cu, and a coating layer mainly composed of Pd and formed over a surface of the core material, wherein the ball portion is formed in non-oxidizing atmosphere gas including hydrocarbon which is gas at room temperature and atmospheric pressure, the method being capable of improving Pd coverage on a ball surface in forming a ball at a tip of the Pd-coated Cu bonding wire.

A wire bond system. Implementations may include: a bond wire including copper (Cu), a bond pad including aluminum (Al) and a sacrificial anode electrically coupled with the bond pad, where the sacrificial anode includes one or more elements having a standard electrode potential below a standard electrode potential of Al.

A wire bond system. Implementations may include: a bond wire including copper (Cu), a bond pad including aluminum (Al) and a sacrificial anode electrically coupled with the bond pad, where the sacrificial anode includes one or more elements having a standard electrode potential below a standard electrode potential of Al.

Wafers and methods of forming solder balls include etching a hole in a final redistribution layer over a terminal contact pad on a wafer to expose the terminal contact pad. Solder is injected into the hole using an injection nozzle that is in direct contact with the final redistribution layer. The final redistribution layer is etched back. The injected solder is reflowed to form a solder ball.

Wafers and methods of forming solder balls include etching a hole in a final redistribution layer over a terminal contact pad on a wafer to expose the terminal contact pad. Solder is injected into the hole using an injection nozzle that is in direct contact with the final redistribution layer. The final redistribution layer is etched back. The injected solder is reflowed to form a solder ball.

Wafers include multiple bulk redistribution layers. A contact pad is formed on a surface of one of the bulk redistribution layers. A final redistribution layer is formed on the surface and in contact with the contact pad. Solder is formed on the contact pad. The solder includes a pedestal portion formed to a same height as the final redistribution layer and a ball portion above the pedestal portion.

Wafers include multiple bulk redistribution layers. A contact pad is formed on a surface of one of the bulk redistribution layers. A final redistribution layer is formed on the surface and in contact with the contact pad. Solder is formed on the contact pad. The solder includes a pedestal portion formed to a same height as the final redistribution layer and a ball portion above the pedestal portion.

A method includes performing a first strike process to strike a metal bump of a first package component against a metal pad of a second package component. A first one of the metal bump and the metal pad includes copper. A second one of the metal bump and the metal pad includes aluminum. The method further includes performing a second strike process to strike the metal bump against the metal pad. An annealing is performed to bond the metal bump on the metal pad.

A method includes performing a first strike process to strike a metal bump of a first package component against a metal pad of a second package component. A first one of the metal bump and the metal pad includes copper. A second one of the metal bump and the metal pad includes aluminum. The method further includes performing a second strike process to strike the metal bump against the metal pad. An annealing is performed to bond the metal bump on the metal pad.