Numerical Analysis of Flow Uniformity in Fan-Out Wafer-Level Packaging Chambers Considering Inlet Shape and Baffle Configuration

Fan-out wafer-level packaging (FOWLP) is an advanced packaging technology that supports high integration and miniaturization of semiconductor devices. In thermal processes, such as soft bake, chamber-internal flow behavior strongly influences wafer temperature uniformity and process reliability. While most previous studies have focused on material properties and thermal stress, quantitative evaluations of flow characteristics inside chambers are limited. This study conducted steady-state computational fluid dynamics (CFD) simulations using ANSYS Fluent^® to investigate the effects of inlet geometry (hole or slit) and the presence or absence of a baffle structure on the internal flow. Velocity and pressure distributions across the wafer surface were analyzed to assess flow uniformity. The results demonstrate that baffle placement and chamber geometry significantly affect flow stability and distribution. Thus, this work provides fundamental insights into optimizing chamber designs, by identifying key flow variables essential for achieving uniform thermal processing in wafer-level manufacturing systems.