Board unit and electronic device

A board unit comprising:

• a board to have an object to be cooled, the object being implemented on the board, the board configured to be capable of being oriented in first and second orientations;
• a baffle plate rotatably coupled to the board and to be displaced to a first rotary position when the board is in the first orientation, to guide a first cooling air, to flow in a first direction with respect to the board, to the object to be cooled and a second rotary position when the board is in the second orientation, to guide a second cooling air, to flow in a second direction with respect to the board, to the object to be cooled;
• and
• an arm to be movably attached to the board and also to be rotatably coupled to a rotary end of the baffle plate to displace the baffle plate to the first rotary position and the second rotary position with movement of the arm.