US Patent 11004831 Stack packages including a fan-out sub-package

A stack package includes a package substrate and a fan-out sub-package mounted on the package substrate using first and second connection bumps. The fan-out sub-package includes a first semiconductor die and redistributed line (RDL) patterns. Second semiconductor dies are stacked on the package substrate to provide a first step structure, and third semiconductor dies are stacked on the second semiconductor dies to provide a second step structure. The second and third semiconductor dies are connected to the package substrate by bonding wires.