| 摘要 |
PROBLEM TO BE SOLVED: To provide a control board capable of reducing the intra-board heating value by cooling only the heat sink fin part where semiconductor elements are mounted, directly with the external air. SOLUTION: A horizontal wind duct 95 is formed with side face walls consisting of sub-unit plate 21 whose rear surface is put in tight attachment to an opening 5C in a partitioning plate and front surface in tight attachment with an opening 6B in a front door and which is furnished with a heat sink 56 where a semiconductor element 52 is installed, and in this airflow duct 95, a heat sink fin part 56B is installed in exposure, and the inside of the duct 95 is air cooled forcedly by an outside air introducing fan 43. |
