“…The waveform of Z th ( t ) characterizes the ability of the considered semiconductor device to dissipate heat generated in it (Górecki and Ptak, 2020; Górecki et al , 2019a; Deng et al , 2017; Avenas et al , 2012). This ability depends on construction of the device case, a manner of assembly of this device and on properties of other components of the heat flow path from the semiconductor structure to the surrounding (Lan and Moo, 2007; Poppe, 2015; Su et al , 2012; Poppe and Szalai, 2014). Some essential elements of this path are the printed circuit board (PCB) and soldering pads to which the LED is soldered (Dziurdzia and Mikołajek, 2017).…”