Experimental and Numerical Investigation of Direct Liquid Jet Impinging Cooling using 3D Printed Manifolds on Lidded and Lidless Packages for 2.5D Integrated Systems

Abstract Package level bare die jet impingement cooling on the chip backside has been previously demonstrated as a highly efficient jet cooling solution for high power devices, by eliminating the thermal interface material. However, bare die jet impingement cooling is a disruptive cooling technology requiring direct access to the backside of the semiconductor device. A less disruptive cooling implementation in which the impingement cooling is applied on the lid is now investigated as an intermediate step. In this work, the first comparison of the cooling performance with the liquid micro-jet array impingement cooling on lidded and bare die package is conducted and experimentally characterized for polymer coolers fabricated by additive manufacturing. The thermal characterization is performed on a 2.5D integrated system that contains two advanced thermal test dies. In addition, besides the reference cooler with vertical coolant supply channel, an improved design of 3D printed fluid delivery manifold with lateral inlet/outlet channels is introduced and benchmarked. The experimental and numerical comparison show that the cooler with the lateral feeding manifold requires 60% less pumping power with respect to the vertical feeding manifold for the same high thermal performance while reducing the overall thickness of the cooling solution by a factor of 2.