A motherboard may have contact pads arranged along a peripheral region on one or both surfaces thereof. A memory module may have unit packages fixed to an upper plate and a lower plate of a module frame. The unit packages may be spaced apart from each other. The upper and the lower unit packages may have contact terminals facing each other. The contact terminals may be elastically bendable, and/or the unit packages may be mounted on the plates via elastic members. The peripheral region of the motherboard may be inserted into the memory module, so the contact terminals of the memory module may elastically contact with and be electrically coupled to the contact pads of the motherboard.