A package on package structure is provided. The package on package structure may include a first substrate having a first center region and a first C-shaped edge region at a first end of the first center region. In example embodiments, the first C-shaped edge region may faun a first space. The package structure may further include at least two first connection pads on an inner surface of the first C-shaped edge region and the at least two first connection pads may be arranged to face one another. In example embodiments, at least one first solder ball may be arranged in the first space and the at least one first solder ball may be connected to the at least two first connection pads.