High performance Cold Plate has been developed by Friction Stir Welding Porcess; The Copper pipe was embedded in the machined groove of aluminum base plate by using Friction Stir Welding , thermal performance of the Cold Plate are approximately 30% higher than that of the conventional Cold Plate fixed by bolts. Strong bonding between copper and aluminum was established by optimizing the  Friction Stir Welding conditions. Lori Quality Engineering was used to seek optimum robust conditions of Friction Stir Welding. Eight control factors were selected from Friction Stir Welding conditions and dimensions of the parts, and noise factors were determined by the gap between the copper pipe and groove of the aluminum base plate. SN ratios of eighteen welded specimens were calculated by thermal performances of specimens. The factorial effects graph was considered from the data of the SN ratios of 18 combinations, the optimum condition was determined by choosing the control factors that had the highest SN ratio. Stable and higher thermal performance was obtained because the Cold Plate was produced under optimum robust condition, even if there were large gaps between copper pipe and aluminum groove before Friction Stir Welding. The Quality Engineering is very effective to seek robust production conditions, many variety of high performance Liquid Cold Plates have been manufactured in short preparation period based on this technique in our company.