Patent ID: 8123109

Claim:
A method of constructing a heat exchanger comprising: providing a plurality of metal walls having a boiling side, a cooling side and at least one bonding surface; applying thermally conductive particles, including particles of a first metal having a first melting temperature mixed with particles of a second metal having a second melting temperature below the first melting temperature, to a boiling side of a plurality of metal components; heating said metal walls with applied thermally conductive particles to a first temperature above the second melting temperature and below the first melting temperature to integrally bond said thermally conductive particles together, to alloy the particles of the second metal with the particles of the first metal, and to metallurgically bond at least the second metal particles of the thermally conductive particles to said boiling side by brazing to form a porous, enhanced boiling surface; assembling said plurality of metal walls with a spacing member so that said boiling sides of said plurality of metal walls define a boiling passage and said cooling sides of said plurality of metal walls define a cooling passage and providing layers of metal between said bonding surfaces of said metal walls and adjacent surfaces of the spacing member; and heating the assembly to a second temperature that is less than said first temperature to bond the layers of metal to at least one of the adjacent surfaces of the spacing member and the bonding surfaces of the metal walls while retaining the porosity of the enhanced boiling surface.