<div class="htmlview paragraph">The hybrid vehicle market is growing rapidly recently, while carmakers are planning to expand their lineup of hybrid vehicles from the compact to the full-size. To make this rapid development possible, the Power Control Unit (PCU) that controls traction motors of hybrid vehicles is required both to be smaller in size for the ease of packaging, and higher in output power to fulfill the need for full-size vehicles.</div> <div class="htmlview paragraph">To achieve both of these targets, we have developed a PCU for the Lexus LS600h with higher output power per volume through significantly improved cooling design for power semiconductor chips by dissipating heat from both sides of them. The following is an overview of the developed technology.</div>