Apparatus and method for semiconductor wafer bumping via injection molded solder

A method for forming solder bumps onto semiconductor structures comprising:

• filling patterned mold cavities formed on a first surface of a mold structure with solder;
• positioning and aligning a patterned first surface of a semiconductor structure directly opposite to said solder filled patterned mold cavities of the mold structure;
• providing a fixture tool for holding and transferring said aligned mold and semiconductor structures together wherein said fixture tool comprises a frame having a central aperture dimensioned to support a substrate and wherein a second surface opposite to said patterned first surface of said semiconductor structure is brought in contact with a first surface of said substrate;
• inserting said fixture tool with the aligned mold and semiconductor structures into solder transfer equipment and transferring the solder from said aligned patterned mold cavities to said aligned patterned semiconductor first surface, wherein said solder transfer equipment comprises:
• a wafer heater stack configured to heat said semiconductor structure;
• a mold heater stack configured to heat said mold structure to a process temperature slightly above said solder's melting point;
• wherein said fixture tool with said aligned mold and semiconductor structures is inserted between said wafer heater stack and said mold heater stack so that a second surface opposite to said first surface of said substrate is in contact with said wafer heater stack and a second surface opposite to said first surface of said mold structure is in contact with said mold heater stack;
• and
• forming a deposition chamber between said wafer heater stack and said mold heater stack by sealing said wafer heater stack and said mold heater stack against said frame.