A notebook personal computer (hereinafter abbreviated as “note PC”) includes a main unit having a keyboard on its upper surface and heat-generating electronic components such as a CPU inside. The main unit is devised in various ways to radiate heat, including providing therein a fan to radiate heat from the heat-generating electronic components.
When a structure, which includes a fan on a second surface of a circuit board having a heat-generating electronic component mounted on a first surface, needs to be employed in consideration of component arrangements, a problem arises how heat from the heat-generating electronic component is efficiently radiated.
Herein, Japanese Laid-open Patent Publication No. 2001-142574 discloses a structure in which a radiation plate is provided on a back surface of a keyboard and the radiation plate is brought into contact with a heat-generating electronic component. In the above-described publication, a fan is further provided to exhaust air in the inside to outside. However, the fan exhausts air which flows along a second surface of the circuit board to the outside. The second surface is a backside of a first surface on which a heat-generating electronic component is mounted. Therefore, there is a problem that radiation efficiency is poor even though the fan is provided.
Moreover, Japanese Laid-open Patent Publication No. 11-307969 discloses a structure in which heat-generating electronic components are mounted on a chassis for heat radiation in place of being mounted on a circuit board. However, when the heat-generating electronic components are provided separately from the circuit board, wiring is very troublesome and assembly becomes very complicated.
Further, Japanese Laid-open Patent Publication No. 2008-28193 discloses a structure in which a hole is formed in a circuit board and air, which is heated by a heat-generating electronic component mounted on a first surface of the circuit board, is passed through the hole, and is guided to a second surface side to be exhausted by a fan. According to this structure, the air heated on the first surface side can be guided to the second surface side and efficiency of heat radiation by the fan can be improved to some degree. However, a problem arises how the air is made to smoothly flow in the hole.
Furthermore, Japanese Laid-open Patent Publication No. 2003-283159 discloses a structure in which a cable is wired by using a groove formed in a chassis, but this has no relation to heat radiation of heat-generating electronic components.