3D IC AlGaN-GaN HEMT BCI-DCTM BGA CFD CoB LEDs DVFS Delphi4LED History of engineering & technology Industry 4.0 Joint Electron Device Engineering Council (JEDEC) metrics LED LED lifetime modelling LED multi-domain modelling LM-80 Light-emitting diodes OpenFOAM ROM SPICE Spice-like modelling of LEDs TDTR TM-21 VO2 accuracy repeatability and reproducibility of thermal measurements beyond CMOS compact thermal model computation time detailed thermal model digital luminaire design digital twin