COOLING STRUCTURE OF PRINTED WIRING BOARD UNIT

PURPOSE:To improve cooling efficiency for a mounted heating part by providing a wind guide plate having an inlet side inclination, for converging a feed air flow toward the heating part, and an outlet side inclination, for diverging an exhaust air flow, and further provided with a projection in contact with the head of the heating part in the plane are between inclined parts. CONSTITUTION:A heating part 1b, such as a semiconductor device, is mounted on a printed wiring board 1a, and a connector and an earthing through hole, through which a fixing screw 4 is inserted to a fixed position on a spacer rod 3, are provided at one end part thereof. the wind guide plate 2 has an inlet side inclined part 2a for converging and guiding a feed air flow 8 for cooling a semiconductor device 1b toward the semiconductor device 1b, and an outlet side inclined part 2b for diverging an exhaust air flow 9 after cooling, and projection 2d, in contact with the flat head surface of the semiconductor device 1b, is provided in the plane area between the both inclined parts 2a, 2b, and mounting holes are provided in the side edges of the both inclined parts 2a, 2b for fixing them to the spacer rod 3. Thus, the speed of the wind passing the heating part 1b can be made larger, and the wind guide plate 2 is used as an auxiliary radiator having a large radiating area via a the projection 2d to largely improve the cooling efficiency.