Electrode assembly for the removal of surface oxides by electron attachment

An apparatus for removing metal oxides from a surface of a substrate comprising a plurality of solder bumps wherein the substrate resides within a target area, the apparatus comprising:

• an at least one energy source;
• at least one gas supply source of a gas mixture comprising a reducing gas;
• and
• an electrode assembly in electrical communication with the at least one energy source and in fluid communication with the at least one gas supply source, comprising:
• a housing that is at least partially comprised of an insulating material and having an internal volume and at least one fluid inlet that is in fluid communication with the internal volume and the at least one gas supply source;
• a conductive base which resides at the bottom of the housing and is connected to the housing comprising a plurality of conductive acicular tips that extend therefrom into the target area and a plurality of perforations that extend through the conductive base and are in fluid communication with the internal volume to allow for a passage of the gas mixture;
• and
• a base electrode proximal to the substrate wherein the substrate is located between the electrode assembly and the base electrode.