Package-on-package (PoP) modules are provided. The PoP module includes a lower package and an upper package disposed over the lower package. The lower package includes a lower substrate and a lower chip disposed over a top surface of the lower substrate. The upper package includes an upper substrate, a plurality of upper chips disposed over a top surface of the upper substrate, and an upper molding member disposed over the plurality of upper chips. The upper molding member is divided into at least two parts which are separated from each other by a trench. Related memory cards and related electronic systems are also provided.