@article{LiuContiBhogarajuetal.2020, author = {Liu, E and Conti, Fosca and Bhogaraju, Sri Krishna and Signorini, Raffaella and Pedron, Danilo and Wunderle, Bernhard and Elger, Gordon}, title = {Thermomechanical stress in GaN-LEDs soldered onto Cu substrates studied using finite element method and Raman spectroscopy}, volume = {51}, journal = {Journal of Raman Spectroscopy}, number = {10}, publisher = {Wiley}, address = {Chichester}, issn = {1097-4555}, doi = {https://doi.org/10.1002/jrs.5947}, pages = {2083 -- 2094}, year = {2020}, abstract = {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.}, language = {en} } @inproceedings{LiuContiBhogarajuetal.2021, author = {Liu, E and Conti, Fosca and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Simulations and experiments to analyze stress phenomena in soldered and sintered interconnections between silicon nitride chips and copper substrates}, booktitle = {2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-1373-2}, doi = {https://doi.org/10.1109/EuroSimE52062.2021.9410869}, year = {2021}, language = {en} } @article{SchmidBhogarajuLiuetal.2020, author = {Schmid, Maximilian and Bhogaraju, Sri Krishna and Liu, E and Elger, Gordon}, title = {Comparison of Nondestructive Testing Methods for Solder, Sinter, and Adhesive Interconnects in Power and Opto-Electronics}, volume = {10}, pages = {8516}, journal = {Applied Sciences}, number = {23}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {https://doi.org/10.3390/app10238516}, year = {2020}, abstract = {Reliability is one of the major requirements for power and opto-electronic devices across all segments. High operation temperature and/or high thermomechanical stress cause defects and degradation of materials and interconnects, which may lead to malfunctions with costly or even life-threatening consequences. To avoid or at least reduce failures, nondestructive testing (NDT) methods are common within development and production of power and opto-electronics. Currently, the dominating NDT methods are X-ray, scanning acoustic microscopy (SAM), and transient thermal analysis (TTA). However, they have different strengths and weaknesses with respect to materials and mechanical designs. This paper compares these NDT methods for different interconnect technologies, i.e., reflow soldering, adhesive, and sintered interconnection. While X-ray provided adequate results for soldered interfaces, inspection of adhesives and sintered interconnects was not possible. With SAM, evaluation of adhesives and sintered interconnects was also feasible, but quality depended strongly on the sample under test. TTA enabled sufficiently detailed results for all the interconnect applications. Automated TTA equipment, as the in-house developed tester used within this investigation, enabled measurement times compatible with SAM and X-ray. In the investigations, all methods revealed their pros and cons, and their selection has to depend on the sample under tests and the required analysis depth and data details. In the paper, guidelines are formulated for an appropriate decision on the NDT method depending on sample and requirements.}, language = {en} } @inproceedings{PascucciContiBhogarajuetal.2021, author = {Pascucci, Jacopo and Conti, Fosca and Bhogaraju, Sri Krishna and Signorini, Raffaella and Liu, E and Pedron, Danilo and Elger, Gordon}, title = {Micro-Raman to detect stress phenomena in Si-chips bonded onto Cu substrates}, booktitle = {Integrated Optics: Design, Devices, Systems and Applications VI}, editor = {Cheben, Pavel and Čtyrok{\´y}, Jiř{\´i} and Molina-Fern{\´a}ndez, I{\~n}igo}, publisher = {SPIE}, address = {Bellingham}, isbn = {978-1-5106-4385-7}, doi = {https://doi.org/10.1117/12.2576414}, year = {2021}, language = {en} } @inproceedings{BhogarajuSchmidHufnageletal.2021, author = {Bhogaraju, Sri Krishna and Schmid, Maximilian and Hufnagel, Elias and Conti, Fosca and Kotadia, Hiren R. and Elger, Gordon}, title = {Low temperature and low pressure die-attach bonding of high power light emitting diodes with self reducing copper complex paste}, booktitle = {IEEE 71st Electronic Components and Technology Conference ECTC 2021, Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-4097-4}, doi = {https://doi.org/10.1109/ECTC32696.2021.00094}, pages = {526 -- 531}, year = {2021}, language = {en} } @inproceedings{SchmidBhogarajuElger2021, author = {Schmid, Maximilian and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Characterization of copper sintered interconnects by transient thermal analysis}, booktitle = {2021 International Conference on Electronics Packaging (ICEP 2021)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-4-9911-9111-4}, doi = {https://doi.org/10.23919/ICEP51988.2021.9451966}, pages = {71 -- 72}, year = {2021}, language = {en} } @inproceedings{ContiLiuBhogarajuetal.2020, author = {Conti, Fosca and Liu, E and Bhogaraju, Sri Krishna and Wunderle, Bernhard and Elger, Gordon}, title = {Finite Element simulations and Raman measurements to investigate thermomechanical stress in GaN-LEDs}, booktitle = {2020 IEEE 8th Electronics System-Integration Technology Conference (ESTC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-6293-5}, doi = {https://doi.org/10.1109/ESTC48849.2020.9229843}, year = {2020}, language = {en} } @inproceedings{BhogarajuContiElger2020, author = {Bhogaraju, Sri Krishna and Conti, Fosca and Elger, Gordon}, title = {Copper die bonding using copper formate based pastes with α-terpineol, amino-2-propanol and hexylamine as binders}, booktitle = {2020 IEEE 8th Electronics System-Integration Technology Conference (ESTC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-6293-5}, doi = {https://doi.org/10.1109/ESTC48849.2020.9229801}, year = {2020}, language = {en} } @inproceedings{ContiLiuBhogarajuetal.2021, author = {Conti, Fosca and Liu, E and Bhogaraju, Sri Krishna and Lenz, Christoph and Seitz, Roland and Elger, Gordon}, title = {Stress evaluations of silicon nitride chips bonded onto copper substrates via SAC soldering, AuSn soldering, and copper sintering}, booktitle = {2020 26th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-7643-7}, doi = {https://doi.org/10.1109/THERMINIC49743.2020.9420523}, pages = {204 -- 208}, year = {2021}, language = {en} } @inproceedings{SchmidBhogarajuRiedeletal.2021, author = {Schmid, Maximilian and Bhogaraju, Sri Krishna and Riedel, Andreas and Elger, Gordon}, title = {Development of an in-line capable transient thermal analysis equipment for a power module with five half bridges}, booktitle = {2020 26th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-7643-7}, doi = {https://doi.org/10.1109/THERMINIC49743.2020.9420493}, pages = {268 -- 273}, year = {2021}, language = {en} } @inproceedings{LiuSchmidBhogarajuetal.2021, author = {Liu, E and Schmid, Maximilian and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Advanced location resolved transient thermal analysis}, booktitle = {2020 26th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-7643-7}, doi = {https://doi.org/10.1109/THERMINIC49743.2020.9420538}, pages = {191 -- 196}, year = {2021}, language = {en} } @article{MokhtariContiSacconetal.2021, author = {Mokhtari, Omid and Conti, Fosca and Saccon, Rodolfo and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Formic acid and formate salts for chemical vapor deposition of copper on glass substrates at atmospheric pressure}, volume = {45}, journal = {New Journal of Chemistry}, number = {43}, publisher = {RSC}, address = {London}, issn = {1369-9261}, doi = {https://doi.org/10.1039/D1NJ02476K}, pages = {20133 -- 20139}, year = {2021}, language = {en} } @article{BhogarajuKotadiaContietal.2021, author = {Bhogaraju, Sri Krishna and Kotadia, Hiren R. and Conti, Fosca and Mauser, Armin and Rubenbauer, Thomas and Bruetting, Robert and Schneider-Ramelow, Martin and Elger, Gordon}, title = {Die-attach bonding with etched micro brass metal pigment flakes for high-power electronics packaging}, volume = {3}, journal = {ACS Applied Electronic Materials}, number = {10}, publisher = {ACS Publications}, address = {Washington}, issn = {2637-6113}, doi = {https://doi.org/10.1021/acsaelm.1c00721}, pages = {4587 -- 4603}, year = {2021}, language = {en} } @article{SchmidBhogarajuHanssetal.2021, author = {Schmid, Maximilian and Bhogaraju, Sri Krishna and Hanss, Alexander and Elger, Gordon}, title = {A new noise-suppression algorithm for transient thermal analysis in semiconductors over pulse superposition}, volume = {70}, pages = {6500409}, journal = {IEEE Transactions on Instrumentation and Measurement}, publisher = {IEEE}, address = {New York}, issn = {0018-9456}, doi = {https://doi.org/10.1109/TIM.2020.3011818}, year = {2021}, language = {en} } @article{BhogarajuMokhtariContietal.2020, author = {Bhogaraju, Sri Krishna and Mokhtari, Omid and Conti, Fosca and Elger, Gordon}, title = {Die-attach bonding for high temperature applications using thermal decomposition of copper(II) formate with polyethylene glycol}, volume = {2020}, journal = {Scripta Materialia}, number = {182}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1359-6462}, doi = {https://doi.org/10.1016/j.scriptamat.2020.02.045}, pages = {74 -- 80}, year = {2020}, language = {en} } @article{BhogarajuContiKotadiaetal.2020, author = {Bhogaraju, Sri Krishna and Conti, Fosca and Kotadia, Hiren R. and Keim, Simon and Tetzlaff, Ulrich and Elger, Gordon}, title = {Novel approach to copper sintering using surface enhanced brass micro flakes for microelectronics packaging}, volume = {2020}, pages = {156043}, journal = {Journal of Alloys and Compounds}, number = {844}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4669}, doi = {https://doi.org/10.1016/j.jallcom.2020.156043}, year = {2020}, language = {en} } @article{MokhtariContiBhogarajuetal.2019, author = {Mokhtari, Omid and Conti, Fosca and Bhogaraju, Sri Krishna and Meier, Markus and Schweigart, Helmut and Tetzlaff, Ulrich and Elger, Gordon}, title = {Characterization of tin-oxides and tin-formate crystals obtained from SnAgCu solder alloy under formic acid vapor}, volume = {43}, journal = {New Journal of Chemistry}, number = {26}, publisher = {RSC}, address = {London}, issn = {1369-9261}, doi = {https://doi.org/10.1039/C9NJ02135C}, pages = {10227 -- 10231}, year = {2019}, language = {en} } @inproceedings{BhogarajuContiSchmidetal.2020, author = {Bhogaraju, Sri Krishna and Conti, Fosca and Schmid, Maximilian and Meier, Markus and Schweigart, Helmut and Elger, Gordon}, title = {Development of sinter paste with surface modified copper alloy particles for die-attach bonding}, booktitle = {ETG-Fachbericht 161, CIPS 2020, 11th International Conference on Integrated Power Electronics Systems}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-5226-3}, url = {https://www.vde-verlag.de/proceedings-de/455225100.html}, pages = {582 -- 587}, year = {2020}, language = {en} } @inproceedings{ElgerLiuContietal.2019, author = {Elger, Gordon and Liu, E and Conti, Fosca and Signorini, Raffaella and Brugnolotto, Enrico and Bhogaraju, Sri Krishna}, title = {Modelling Thermo-Mechanical Stress in GaN-LEDs Soldered on Copper Substrate with Simulations Validated by Raman Experiments}, booktitle = {2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-8040-7}, doi = {https://doi.org/10.1109/EuroSimE.2019.8724533}, year = {2019}, language = {en} } @inproceedings{ElgerMokhtariBhogarajuetal.2020, author = {Elger, Gordon and Mokhtari, Omid and Bhogaraju, Sri Krishna and Conti, Fosca and Meier, Markus and Schweigart, Helmut}, title = {Analyse der Reaktionsprodukte von Metall-Formiaten im r{\"u}ckstandfreien L{\"o}tprozess}, booktitle = {GMM-Fb. 94: EBL 2020 - Elektronische Baugruppen und Leiterplatten}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-5185-3}, doi = {https://www.vde-verlag.de/proceedings-de/455185053.html}, year = {2020}, language = {de} } @inproceedings{BhogarajuMokhtariPascuccietal.2019, author = {Bhogaraju, Sri Krishna and Mokhtari, Omid and Pascucci, Jacopo and Conti, Fosca and Kotadia, Hiren R. and Elger, Gordon}, title = {A multi-pronged approach to low-pressure Cu sintering using surface-modified particles, substrate and chip metallization}, volume = {2019}, booktitle = {International Symposium on Microelectronics}, number = {1}, publisher = {IMAPS}, address = {Pittsburgh}, issn = {2380-4505}, doi = {https://doi.org/10.4071/2380-4505-2019.1.000387}, pages = {387 -- 392}, year = {2019}, language = {en} } @inproceedings{BhogarajuMokhtariPascuccietal.2019, author = {Bhogaraju, Sri Krishna and Mokhtari, Omid and Pascucci, Jacopo and Conti, Fosca and Elger, Gordon}, title = {Improved sinterability of particles to substrates by surface modifications on substrate metallization}, volume = {2019}, booktitle = {Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT)}, number = {HiTen}, publisher = {IMAPS}, address = {Pittsburgh (PA)}, issn = {2380-4491}, doi = {https://doi.org/10.4071/2380-4491.2019.HiTen.000066}, pages = {66 -- 70}, year = {2019}, language = {en} } @inproceedings{SignoriniContiBrugnolottoetal.2019, author = {Signorini, Raffaella and Conti, Fosca and Brugnolotto, Enrico and Pedron, Danilo and Liu, E and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Thermomechanical local stress in assembled GaN LEDs investigated by Raman optical spectroscopy}, booktitle = {Integrated Optics: Design, Devices, Systems, and Applications V}, editor = {Cheben, Pavel and Čtyrok{\´y}, Jiř{\´i} and Molina-Fern{\´a}ndez, I{\~n}igo}, publisher = {SPIE}, address = {Bellingham}, isbn = {978-1-5106-2729-1}, doi = {https://doi.org/10.1117/12.2520992}, year = {2019}, language = {en} } @inproceedings{SchmidHanssBhogarajuetal.2019, author = {Schmid, Maximilian and Hanss, Alexander and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Time saving averaging algorithm for transient thermal analyses over deterministic pulse superposition}, booktitle = {2019 25th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2078-2}, doi = {https://doi.org/10.1109/THERMINIC.2019.8923548}, year = {2019}, language = {en} } @inproceedings{BrugnolottoBhogarajuLiuetal.2019, author = {Brugnolotto, Enrico and Bhogaraju, Sri Krishna and Liu, E and Conti, Fosca and Pedron, Danilo and Signorini, Raffaella and Elger, Gordon}, title = {Investigation of thermomechanical local stress induced in assembled GaN LEDs}, booktitle = {2019 25th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2078-2}, doi = {https://doi.org/10.1109/THERMINIC.2019.8923629}, year = {2019}, language = {en} } @inproceedings{SchmidBhogarajuElger2019, author = {Schmid, Maximilian and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Automatic transient thermal impedance tester for quality inspection of soldered and sintered power electronic devices on panel and tile level}, booktitle = {2019 IEEE 69th Electronic Components and Technology Conference (ECTC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-1499-6}, doi = {https://doi.org/10.1109/ECTC.2019.00320}, pages = {2324 -- 2330}, year = {2019}, language = {en} } @inproceedings{SchmidHermannBhogarajuetal.2022, author = {Schmid, Maximilian and Hermann, Joseph and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Reliability of SAC Solders under Low and High Stress Conditions}, booktitle = {2022 IEEE 9th Electronics System-Integration Technology Conference (ESTC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-8947-8}, doi = {https://doi.org/10.1109/ESTC55720.2022.9939394}, pages = {553 -- 559}, year = {2022}, language = {en} } @inproceedings{LiuBhogarajuLuxetal.2022, author = {Liu, E and Bhogaraju, Sri Krishna and Lux, Kerstin and Elger, Gordon and Mou, Rokeya Mumtahana}, title = {Investigation Of Stress Generated By Interconnection Processes With Micro-Raman Spectroscopy (μRS)}, booktitle = {Proceedings IEEE 72nd Electronic Components and Technology Conference: ECTC 2022}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-7943-1}, doi = {https://doi.org/10.1109/ECTC51906.2022.00123}, pages = {739 -- 745}, year = {2022}, language = {en} } @inproceedings{SacconBeninBhogarajuetal.2022, author = {Saccon, Rodolfo and Benin, Alice and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Effect of binders on the performance of copper sintering pastes}, booktitle = {2022 International Conference on Electronics Packaging (ICEP 2022)}, publisher = {IEEE}, address = {Piscataway (NJ)}, isbn = {978-4-9911911-3-8}, doi = {https://doi.org/10.23919/ICEP55381.2022.9795555}, pages = {71 -- 72}, year = {2022}, language = {en} } @inproceedings{HanssSchmidBhogarajuetal.2018, author = {Hanss, Alexander and Schmid, Maximilian and Bhogaraju, Sri Krishna and Conti, Fosca and Elger, Gordon}, title = {Reliability of sintered and soldered high power chip size packages and flip chip LEDs}, booktitle = {ECTC - The 2018 IEEE 68th Electronic Components and Technology Conference: Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-5000-4}, doi = {https://doi.org/10.1109/ECTC.2018.00312}, pages = {2080 -- 2088}, year = {2018}, language = {en} } @inproceedings{BhogarajuMokhtariPascuccietal.2020, author = {Bhogaraju, Sri Krishna and Mokhtari, Omid and Pascucci, Jacopo and Hanss, Alexander and Schmid, Maximilian and Conti, Fosca and Elger, Gordon}, title = {Hybrid Cu particle paste with surface-modified particles for high temperature electronics packaging}, booktitle = {Proceedings 22nd European Microelectronics and Packaging Conference, EMPC}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-6291-1}, doi = {https://doi.org/10.23919/EMPC44848.2019.8951887}, year = {2020}, language = {en} } @inproceedings{HanssSchmidBhogarajuetal.2018, author = {Hanss, Alexander and Schmid, Maximilian and Bhogaraju, Sri Krishna and Conti, Fosca and Elger, Gordon}, title = {Process development and reliability of sintered high power chip size packages and flip chip LEDs}, booktitle = {2018 International Conference on Electronics Packaging and iMAPS All Asia Conference (ICEP-IAAC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-4-9902-1885-0}, doi = {https://doi.org/10.23919/ICEP.2018.8374351}, pages = {479 -- 484}, year = {2018}, language = {en} } @inproceedings{BhogarajuHanssSchmidetal.2018, author = {Bhogaraju, Sri Krishna and Hanss, Alexander and Schmid, Maximilian and Elger, Gordon and Conti, Fosca}, title = {Evaluation of silver and copper sintering of first level interconnects for high power LEDs}, booktitle = {2018 7th Electronic System-Integration Technology Conference (ESTC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6814-6}, doi = {https://doi.org/10.1109/ESTC.2018.8546499}, year = {2018}, language = {en} } @article{ContiHanssMokhtarietal.2018, author = {Conti, Fosca and Hanss, Alexander and Mokhtari, Omid and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Formation of tin-based crystals from a SnAgCu alloy under formic acid vapor}, volume = {42}, journal = {New Journal of Chemistry}, number = {23}, publisher = {RSC}, address = {London}, issn = {1369-9261}, doi = {https://doi.org/10.1039/C8NJ04173C}, pages = {19232 -- 19236}, year = {2018}, language = {en} } @inproceedings{BhogarajuSchmidLiuetal.2022, author = {Bhogaraju, Sri Krishna and Schmid, Maximilian and Liu, E and Saccon, Rodolfo and Elger, Gordon and Klassen, Holger and M{\"u}ller, Klaus and Pirzer, Georg}, title = {Low cost copper based sintered interconnect material for optoelectronics packaging}, booktitle = {2022 IEEE 72nd Electronic Components and Technology Conference (ECTC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-7943-1}, doi = {https://doi.org/10.1109/ECTC51906.2022.00270}, pages = {1720 -- 1725}, year = {2022}, language = {en} } @inproceedings{SignoriniPedronContietal.2018, author = {Signorini, Raffaella and Pedron, Danilo and Conti, Fosca and Hanss, Alexander and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Thermomechanical Stress in GaN LED Soldered on Copper Substrate Evaluated by Raman Measurements and Computer Modelling}, booktitle = {2018 24rd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6759-0}, doi = {https://doi.org/10.1109/THERMINIC.2018.8593304}, year = {2018}, language = {en} } @article{LiuBhogarajuWunderleetal.2022, author = {Liu, E and Bhogaraju, Sri Krishna and Wunderle, Bernhard and Elger, Gordon}, title = {Investigation of stress relaxation in SAC305 with micro-Raman spectroscopy}, volume = {2022}, pages = {114664}, journal = {Microelectronics Reliability}, number = {138}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0026-2714}, doi = {https://doi.org/10.1016/j.microrel.2022.114664}, year = {2022}, language = {en} } @inproceedings{MohanBhogarajuLysienetal.2021, author = {Mohan, Nihesh and Bhogaraju, Sri Krishna and Lysien, Mateusz and Schneider, Ludovic and Granek, Filip and Lux, Kerstin and Elger, Gordon}, title = {Drop feature optimization for fine trace inkjet printing}, booktitle = {2021 23rd European Microelectronics and Packaging Conference \& Exhibition (EMPC): Technical Papers}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-0-9568086-7-7}, doi = {https://doi.org/10.23919/EMPC53418.2021.9585004}, year = {2021}, language = {en} } @inproceedings{BhogarajuSchmidKotadiaetal.2021, author = {Bhogaraju, Sri Krishna and Schmid, Maximilian and Kotadia, Hiren R. and Conti, Fosca and Elger, Gordon}, title = {Highly reliable die-attach bonding with etched brass flakes}, booktitle = {2021 23rd European Microelectronics and Packaging Conference \& Exhibition (EMPC): Technical Papers}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-0-9568086-7-7}, doi = {https://doi.org/10.23919/EMPC53418.2021.9584967}, year = {2021}, language = {en} } @inproceedings{SteinbergerBhogarajuElger2023, author = {Steinberger, Fabian and Bhogaraju, Sri Krishna and Elger, Gordon}, title = {Correlation between the characteristics of printed sinter paste and the quality of sintered interconnects through non-destructive analysis techniques}, booktitle = {NordPac 2023 Annual Microelectronics and Packaging Conference and Exhibition: Reviewed Papers}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-91-89821-06-4}, doi = {https://doi.org/10.23919/NordPac58023.2023.10186250}, year = {2023}, language = {en} } @article{MohanAhuirTorresBhogarajuetal.2024, author = {Mohan, Nihesh and Ahuir-Torres, Juan Ignacio and Bhogaraju, Sri Krishna and Webler, Ralf and Kotadia, Hiren R. and Erdogan, H{\"u}seyin and Elger, Gordon}, title = {Decomposition mechanism and morphological evolution of in situ realized Cu nanoparticles in Cu complex inks}, volume = {48}, journal = {New Journal of Chemistry}, number = {15}, publisher = {RSC}, address = {London}, issn = {1369-9261}, doi = {https://doi.org/10.1039/D3NJ05185D}, pages = {6796 -- 6808}, year = {2024}, language = {en} } @inproceedings{MohanAhuirTorresBhogarajuetal.2024, author = {Mohan, Nihesh and Ahuir-Torres, Juan Ignacio and Bhogaraju, Sri Krishna and Kotadia, Hiren R. and Elger, Gordon}, title = {Rapid Sintering of Inkjet Printed Cu Complex Inks Using Laser in Air}, booktitle = {2023 24th European Microelectronics and Packaging Conference \& Exhibition (EMPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-0-9568086-9-1}, doi = {https://doi.org/10.23919/EMPC55870.2023.10418323}, year = {2024}, language = {en} } @inproceedings{BhogarajuUgoliniBelponeretal.2024, author = {Bhogaraju, Sri Krishna and Ugolini, Francesco and Belponer, Federico and Greci, Alessio and Elger, Gordon}, title = {Reliability of Copper Sintered Interconnects Under Extreme Thermal Shock Conditions}, booktitle = {2023 24th European Microelectronics and Packaging Conference \& Exhibition (EMPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-0-9568086-9-1}, doi = {https://doi.org/10.23919/EMPC55870.2023.10418348}, year = {2024}, language = {en} } @inproceedings{BhogarajuMohanSteinbergeretal.2024, author = {Bhogaraju, Sri Krishna and Mohan, Nihesh and Steinberger, Fabian and Erdogan, H{\"u}seyin and Hadrava, Philipp and Elger, Gordon}, title = {Novel Low Temperature and Low Pressure Sintering of ADAS Radar Sensor Antenna Stack}, booktitle = {2023 24th European Microelectronics and Packaging Conference \& Exhibition (EMPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-0-9568086-9-1}, doi = {https://doi.org/10.23919/EMPC55870.2023.10418277}, year = {2024}, language = {en} } @inproceedings{AhuirTorresBhogarajuWestetal.2024, author = {Ahuir-Torres, Juan Ignacio and Bhogaraju, Sri Krishna and West, Geoff and Elger, Gordon and Kotadia, Hiren R.}, title = {Understanding Cu Sintering and Its Role on Corrosion Behaviour for High-Temperature Microelectronic Application}, booktitle = {2023 24th European Microelectronics and Packaging Conference \& Exhibition (EMPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-0-9568086-9-1}, doi = {https://doi.org/10.23919/EMPC55870.2023.10418365}, year = {2024}, language = {en} } @article{ElgerBhogarajuSchneiderRamelow2024, author = {Elger, Gordon and Bhogaraju, Sri Krishna and Schneider-Ramelow, Martin}, title = {Hybrid Cu sinter paste for low temperature bonding of bare semiconductors}, volume = {2024}, pages = {136973}, journal = {Materials Letters}, number = {372}, publisher = {Elsevier}, address = {New York}, issn = {1873-4979}, doi = {https://doi.org/10.1016/j.matlet.2024.136973}, year = {2024}, abstract = {A novel hybrid copper paste was developed for low temperature sintering of bare semiconductors. Cu(II) formate (Cu(for)) is complexed in amino-2-propanol (A2P) and added to a paste of etched brass micro flakes. A two-step sintering process is applied: The paste is printed and dried at 120 °C under formic acid (FA) enriched N2 atmosphere (FAN2) for 5 min. Afterwards, bare semiconductors are placed and sintered at 250 °C for 5 min applying a bonding pressure of 20 MPa/10 MPa. By the thermal decomposition of the Cu(for) atomic Cu is released and forms in-situ Cu-nanoparticles. An interconnect is realized with shear strength >100 MPa.}, language = {en} } @inproceedings{ParetBhogarajuBusseetal.2024, author = {Paret, Paul and Bhogaraju, Sri Krishna and Busse, Dirk and Dahlb{\"u}dding, Alexander and Elger, Gordon and Narumanchi, Sreekant}, title = {Thermomechanical Degradation of Sintered Copper under High-Temperature Thermal Shock}, booktitle = {Proceedings: IEEE 74th Electronic Components and Technology Conference, ECTC 2024}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3503-7598-5}, doi = {https://doi.org/10.1109/ECTC51529.2024.00196}, pages = {1219 -- 1224}, year = {2024}, language = {en} } @inproceedings{ContiLuxBhogarajuetal.2021, author = {Conti, Fosca and Lux, Kerstin and Bhogaraju, Sri Krishna and Liu, E and Lenz, Christoph and Seitz, Roland and Elger, Gordon}, title = {Raman spectroscopy to investigate gallium nitride light emitting diodes after assembling onto copper substrates}, booktitle = {Optical Sensors 2021}, editor = {Baldini, Francesco and Homola, Jiri and Lieberman, Robert A.}, publisher = {SPIE}, address = {Bellingham}, isbn = {978-1-5106-4379-6}, doi = {https://doi.org/10.1117/12.2591947}, year = {2021}, language = {en} } @inproceedings{PandeyBhogarajuLuxetal.2022, author = {Pandey, Amit and Bhogaraju, Sri Krishna and Lux, Kerstin and Elger, Gordon}, title = {Analysis of stress in spherically bent thinned image sensors}, booktitle = {2022 23rd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-6654-5836-8}, doi = {https://doi.org/10.1109/EuroSimE54907.2022.9758847}, year = {2022}, language = {en} }