Multimesa versus annular construction for high average power in semiconductor devices

The thermal resistance performance of and total material area required for various arrangements of three or more active devices in regular patterns are compared to the equivalent quantities for single mesa devices and annular devices of varying ratios of thickness to diameter. Triangular (trimesa), square (quadrimesa), centered-square (pentamesa), and arrays of mesas are considered. A closed-form solution for the temperature distribution both inside and outside the periphery of each mesa allows consideration of thermal interaction among mesas. Results are presented in the form of plots useful for design.