Abstract: Embodiments include a base for an electrostatic chuck (ESC) assembly for supporting a workpiece during a manufacturing operation in a processing chamber, such as a plasma etch, clean, deposition system, or the like. Inner and outer fluid conduits are disposed in the base to conduct a heat transfer fluid. In embodiments, a counter-flow conduit configuration provides improved temperature uniformity. The conduit segments in each zone are interlaced so that fluid flows are in opposite directions in radially adjacent segments. In embodiments, each separate fluid conduit formed in the base comprises a channel formed in the base with a cap e-beam welded to a recessed lip of the channel to make a sealed conduit. To further improve the thermal uniformity, a compact, tri-fold channel segment is employed in each of the outer fluid loops. In further embodiments, the base includes a multi-contact fitting RF and DC connection, and thermal breaks.