Solder bumps are provided on round wafers through the use of injection molded solder. Copper pillars or ball limiting metallurgy are formed over I/O pads within the channels of a patterned mask layer. Solder is injected over the pillars or BLM, filling the channels. Molten solder can be injected in cavities formed in round wafers without leakage using a carrier assembly that accommodates wafers that have been previously subjected to mask layer deposition and patterning. One such carrier assembly includes an elastomeric body portion having a round recess, the walls of the recess forming a tight seal with the round wafer. Other carrier assemblies employ adhesives applied around the peripheral edges of the wafers to ensure sealing between the carrier assemblies and wafers.