Condenser fin structures facilitating vapor condensation cooling of coolant

A cooling apparatus comprising:

• a housing configured to at least partially surround and form a sealed compartment about an electronic device to be cooled;
• a dielectric fluid disposed within the sealed compartment, wherein the electronic device to be cooled is at least partially immersed within the dielectric fluid;
• and
• a vapor condenser, the vapor condenser comprising a thermally conductive base structure and a plurality of thermally conductive condenser fins extending from the thermally conductive base structure into the sealed compartment in an upper portion of the sealed compartment, the plurality of thermally conductive condenser fins facilitating cooling of dielectric fluid vapor rising to the upper portion of the sealed compartment, and wherein at least one thermally conductive condenser fin of the plurality of thermally conductive condenser fins has a varying transverse cross-sectional perimeter along at least a portion of its length, the transverse cross-sectional perimeter of the at least one thermally conductive condenser fin increasing in a direction of condensate travel along the at least a portion of the at least one thermally conductive condenser fin, the increasing transverse cross-sectional perimeter being pre-configured to reduce a thickness of dielectric fluid condensate film forming on the at least one thermally conductive condenser fin.