Vapor heat spreader

A circuit module is provided that includes a system for reducing thermal variation and cooling the circuit module. The module includes a thermally-conductive rigid substrate having first and second lateral sides and an edge. Flex circuitry populated with a plurality of ICs and exhibiting a connective facility that comprises plural contacts for use with an edge connector is wrapped about the edge of the thermally-conductive substrate. Heat from the plurality of ICs is thermally-conducted by the thermally-conductive substrate. The module also includes one or more heat pipes. Each heat pipe is sealed water-tight and includes a wick and a vaporizable fluid.