Cooling device and electronic device

1. An electronic device comprising: a housing; a cooling device in the housing; and a printed circuit board in the housing and comprising a heat generating part, a first surface facing the cooling device, a second surface on an opposite side to the first surface, and an opening portion, wherein the cooling device further comprising: a heat diffusion plate comprising a third surface facing the printed circuit board, a heat receiving portion on the heat diffusion plate and thermally connected to the heat generating part, a heat sink on the heat diffusion plate, that releases, heat from the heat receiving portion to outside, a heat pipe comprising a first end portion to be connected to the heat receiving portion and a second end portion on an opposite side to the first end portion and to be connected to the heat sink, and a fan unit that promotes heat radiation of the heat sink on the heat diffusion plate, the fan unit being arranged within a height defined by the second surface and the third surface and a part of the fan unit is in the interior of the opening portion.

2. The electronic device according to claim 1 , further comprising a connecting mechanism in the housing, which fixes the cooling device to a stud, wherein the printed circuit board comprises the stud for installing the cooling device, the heat diffusion plate comprises a step portion which is bent to form a recess; the cooling device is arranged between the printed circuit board and the connecting mechanism, and the connecting mechanism is opposed to the heat diffusion plate in the recess.