Expansion card device

An expansion card device, having a first height, comprising:

• a housing, comprising two plates and a base, wherein the base comprises two assembly portions and a partition portion, the two assembly portions respectively connect to two opposite sides of the partition portion, and the two assembly portions protrude in opposite directions of the partition portion, the two assembly portions respectively fix to the two plates to define two accommodation spaces between the two plates;
• and
• two expansion card assemblies, each having a second height and comprising:
• a mounting bracket;
• and
• an expansion card, comprising a circuit board assembly and a bracket, wherein the circuit board assembly comprises a mounting surface and an abutment surface adjacent to each other, the bracket dispose on the mounting surface of the circuit board assembly, and the bracket comprises a coupling portion, and a part of the coupling portion sticks out of the abutment surface and assembled to the mounting bracket;
• wherein the two expansion card assemblies are respectively located in the two accommodation spaces, the two abutment surfaces of the two expansion card assemblies both face the base, and the two coupling portions of the two brackets are respectively adjacent to the two plates and are staggered from each other, forming an overlapping region of a third height in a height direction.