System and method for operating an electric power converter

A heat removal system for at least one semiconductor device, the semiconductor device including a substrate defining a plurality of heat transfer surfaces thereon and at least one semiconductor die coupled to the substrate, said heat removal system comprising:

• at least one immersion structure defining at least one immersion cavity therein;
• a vapor channel conduit positioned within said immersion cavity;
• a liquid return conduit positioned within said immersion cavtity;
• and,
• an immersion cavity exit conduit coupled in flow communication to said vapor channel conduit and said liquid return conduit;
• and,
• a liquid at least partially filling said immersion cavity such that the semiconductor die is fully immersed in and in direct contact with said liquid and at least a portion of both sides of the heat transfer surfaces on the substrate are immersed in and in direct contact with said liquid, wherein heat generated in said semiconductor device induces a phase change in said liquid to a vapor to induce a natural, unforced circulation flow of said vapor, wherein said vapor conduit channel configured to channel said vapor to said immersion cavity exit conduit, said immersion cavity exit conduit configured to induce another phase change of the vapor back to said liquid, and said liquid return conduit configured to channel said liquid to said immersion cavity.

A method of operating a heat removal system for an electric power converter including at least one semiconductor device and at least one immersion structure defining at least one immersion cavity therein, the semiconductor device positioned within the immersion cavity, the semiconductor device includes a substrate and at least one semiconductor die coupled to a first side of the substrate and a second side of the substrate, the immersion cavity is at least partially filled with a liquid such that the semiconductor die is fully immersed in and in direct contact with the liquid and at least a portion of both sides of the substrate are immersed in and in direct contact with the liquid, said method comprising:

• energizing the semiconductor device;
• generating heat in the semiconductor die and transferring at least a portion of the heat to the first side and the second side of the substrate;
• and,
• removing heat from the semiconductor die and at least a portion of the first side and second side of the substrate comprising inducing a phase change in the liquid to a vapor;
• inducing a natural, unforced circulation flow of the vapor within a vapor channeling conduit;
• removing heat from the vapor comprising inducing another phase change in the vapor back to the liquid;
• and
• channeling the liquid through a liquid return conduit and into the immersion cavity.