Referring to FIGS. 2 to 5, the memory module 110 may include a module board BDH, a memory connector MCN provided on at least one end of the module board BDH, and an electronic element CHP placed on at least one face of the module board BDH.

The module board BDH may include one or more insulating layers and wiring layers. The module board BDH may include a printed circuit board.

The module board BDH may have a plate-like shape. The module board BDH may be placed approximately on the XY plane. The overall planar shape of the module board BDH may be similar to the planar shape of the memory device 100. For example, if the memory device 100 has a rectangular or similar appearance in a plan view, the module board BDH may also have a rectangular or similar appearance.

The size of the module board BDH in the plan view is smaller than the size of the memory device 100, but it may be approximated to the size of the memory device 100. For example, in the area occupied by the memory device 100, the area occupied by the module board BDH may be in the range of 50% to 99%.

The module board BDH occupies the central part of the memory device 100 in the plan view, and each side of the module board BDH may be located on the inside from each corresponding side of the memory device 100 (i.e., each side of the module board BDH is spaced inwardly from the corresponding sides of the memory device 100). Except for some sections, the enclosure assembly 120 is placed outside the module board BDH in the space between each side of the module board BDH and each side of the memory device 100 to prevent exposure of the module board BDH to the outside.