Design and Development of Manifolds for Parallel Flow and Counter Flow in Two-Phase Cooling of 3D ICs

3D ICs provide a promising technique to circumvent the scaling limit of semiconductor process technology. However, heat dissipation can be a great challenge and requires high-efficient cooling solutions. This study developed manifolds for embedded micro-pin fin heat sinks (MPFHSs) in two-phase liquid cooling of 3D ICs and built a cooling loop for experimental characterization. The targeted heat flux is 600 W/cm ² for each layer of 3D ICs. The manifold is fabricated by 3D printing using stainless steel. To compare and improve the cooling effect, two flow paths, i.e., parallel flow and counter flow, are designed. The flow distribution and pressure drop of manifolds are numerically simulated and analyzed using ANSYS Fluent software. The results show that the parallel flow provides a more uniform flow distribution and smaller pressure drop compared to the counter flow, which is reasonable since the channel of parallel flow is wider. The counter flow provides larger fluid velocity, hence, stronger heat transfer. In addition, further reducing the manifold size can lead to worse flow distribution and higher pressure drop.