Abstract: A ceramic card assembly which provides high density three dimensional semiconductor device packaging and overcomes the power distribution and thermal management problems that have impaired prior ceramic cards. The ceramic card assembly combines ceramic cards with flexible power distribution structures which provide low inductance and low resistance power distribution, making ceramic cards available for high performance VLSI systems. Each ceramic card assembly comprises a ceramic card having a plurality of chip sites and power contacts thereon, and at least one flexible power distribution structure having alternating insulation (i.e. polyimide) layers and conductor (i.e., copper) layers, the flexible power distribution structures are mounted adjacent to the ceramic cards so that conductive layers of the ceramic cards are selectively exposed to the power contacts. The ceramic card assemblies are preferably combined into a field replaceable unit that includes cold plates between ceramic cards.