Electronic device comprising thermal diffusion member

An electronic device comprising:

• a first housing comprising a first side surface, a second side surface, and a third side surface;
• a second housing comprising a fourth side surface, a fifth side surface, and a sixth side surface, the second housing being configured to be slidable into and out of the first housing;
• a sliding plate comprising a first end coupled to the first housing, and a second end configured to be at least partially slid within the second housing;
• a flexible display supported by the first housing and the second housing and comprising a display area that varies as the second housing slides into and out of the first housing;
• a printed circuit board disposed in an inner space of the first housing;
• at least one electronic component mounted on a side of the printed circuit board;
• a first shaft comprising a first end coupled to the fourth side surface of the second housing, and a second end coupled to the sixth side surface of the second housing;
• and
• a thermal diffusion member comprising a first end disposed on the at least one electronic component and a second end coupled to the first shaft, the thermal diffusion member being configured to be partially wound around and unwound from the first shaft,
• wherein the thermal diffusion member is configured such that at least a portion of the thermal diffusion member spreads out in an inner space of the second housing as a sliding-out operation is performed by the second housing with respect to the first housing.