A more efficient cooling system for densely packed electronic components for use in an out-of-doors equipment enclosure. An array of cooling assemblies are placed on heat generating components mounted to printed circuit boards mounted in enclosure racks. Each board has a manifold for intake and exhaust of refrigerant, and larger rack manifolds are substituted for rails and are attached to a backplane. A hybrid package including a ceramic hybrid power module and an attached array of cooling assemblies provide even more density of components and improved cooling.