The proper placement of elements to ensure optimal reliability and desirable levels of temperature coupling for high-power hybrid (HPH) device is proposed by Maly and Piotrowski [8]. Placements for both reliability and wirability considerations are presented for convectively cooled printed circuits boards (PCB) [9]. For other thermal placement methods, it can be referred to the Refs. [10–12]. It should be noted that the thermal resistances defined in these studies are considered as pre-assumed constant