TY - JOUR A1 - Liu, E A1 - Conti, Fosca A1 - Bhogaraju, Sri Krishna A1 - Signorini, Raffaella A1 - Pedron, Danilo A1 - Wunderle, Bernhard A1 - Elger, Gordon T1 - Thermomechanical stress in GaN-LEDs soldered onto Cu substrates studied using finite element method and Raman spectroscopy JF - Journal of Raman Spectroscopy N2 - Local thermomechanical stress can cause failures in semiconductor packages during long-time operation under harsh environmental conditions. This study helps to explain the packaging-induced stress in blue GaN-LEDs soldered onto copper substrates using AuSn alloy as lead-free interconnect material. Based on the finite element method, a virtual prototype is developed to simulate the thermomechanical behavior and stress in the LED and in the complete LED/AuSn/Cu assembly considering plastic and viscoplastic strain. The investigations were performed by varying the temperature between −50°C and 180°C. To validate the model, the simulation results are compared to experimental data collected with Raman spectroscopy. Studies of the urn:x-wiley:03770486:media:jrs5947:jrs5947-math-0003 phonon mode of GaN semiconductor are elaborated to understand the induced thermomechanical stress. The model enables evaluation of the stress in the interfaces of the assembly, which otherwise cannot be accessed by measurements. It serves to predict how assemblies would perform, before committing resources to build a physical prototype. UR - https://doi.org/10.1002/jrs.5947 KW - finite element method KW - gallium nitride (GaN) KW - LED KW - semiconductor KW - thermomechanical stress Y1 - 2020 UR - https://doi.org/10.1002/jrs.5947 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-9438 SN - 1097-4555 VL - 51 IS - 10 SP - 2083 EP - 2094 PB - Wiley CY - Chichester ER - TY - CHAP A1 - Pascucci, Jacopo A1 - Conti, Fosca A1 - Bhogaraju, Sri Krishna A1 - Signorini, Raffaella A1 - Liu, E A1 - Pedron, Danilo A1 - Elger, Gordon ED - Cheben, Pavel ED - Čtyroký, Jiří ED - Molina-Fernández, Iñigo T1 - Micro-Raman to detect stress phenomena in Si-chips bonded onto Cu substrates T2 - Integrated Optics: Design, Devices, Systems and Applications VI UR - https://doi.org/10.1117/12.2576414 Y1 - 2021 UR - https://doi.org/10.1117/12.2576414 SN - 978-1-5106-4385-7 N1 - Poster + Paper PB - SPIE CY - Bellingham ER - TY - CHAP A1 - Signorini, Raffaella A1 - Conti, Fosca A1 - Brugnolotto, Enrico A1 - Pedron, Danilo A1 - Liu, E A1 - Bhogaraju, Sri Krishna A1 - Elger, Gordon ED - Cheben, Pavel ED - Čtyroký, Jiří ED - Molina-Fernández, Iñigo T1 - Thermomechanical local stress in assembled GaN LEDs investigated by Raman optical spectroscopy T2 - Integrated Optics: Design, Devices, Systems, and Applications V UR - https://doi.org/10.1117/12.2520992 Y1 - 2019 UR - https://doi.org/10.1117/12.2520992 SN - 978-1-5106-2729-1 N1 - Presentation + Paper PB - SPIE CY - Bellingham ER - TY - CHAP A1 - Brugnolotto, Enrico A1 - Bhogaraju, Sri Krishna A1 - Liu, E A1 - Conti, Fosca A1 - Pedron, Danilo A1 - Signorini, Raffaella A1 - Elger, Gordon T1 - Investigation of thermomechanical local stress induced in assembled GaN LEDs T2 - 2019 25th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC) UR - https://doi.org/10.1109/THERMINIC.2019.8923629 Y1 - 2019 UR - https://doi.org/10.1109/THERMINIC.2019.8923629 SN - 978-1-7281-2078-2 PB - IEEE CY - Piscataway ER - TY - CHAP A1 - Signorini, Raffaella A1 - Pedron, Danilo A1 - Conti, Fosca A1 - Hanss, Alexander A1 - Bhogaraju, Sri Krishna A1 - Elger, Gordon T1 - Thermomechanical Stress in GaN LED Soldered on Copper Substrate Evaluated by Raman Measurements and Computer Modelling T2 - 2018 24rd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC) UR - https://doi.org/10.1109/THERMINIC.2018.8593304 KW - Stress KW - Light emitting diodes KW - Gallium nitride KW - Phonons KW - Substrates KW - Temperature measurement KW - Silicon Y1 - 2018 UR - https://doi.org/10.1109/THERMINIC.2018.8593304 SN - 978-1-5386-6759-0 PB - IEEE CY - Piscataway ER -