@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{StenzelSchmidKoelleetal.2024, author = {Stenzel, Gerhard and Schmid, Kyrill and K{\"o}lle, Michael and Altmann, Philipp and Lingsch-Rosenfeld, Marian and Zorn, Maximilian and B{\"u}cher, Tim and Gabor, Thomas and Wirsing, Martin and Belzner, Lenz}, title = {SEGym: Optimizing Large Language Model Assisted Software Engineering Agents with Reinforcement Learning}, booktitle = {Bridging the Gap Between AI and Reality, Second International Conference, AISoLA 2024, Crete, Greece, October 30 - November 3, 2024, Proceedings}, editor = {Steffen, Bernhard}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-75434-0}, doi = {https://doi.org/10.1007/978-3-031-75434-0_8}, pages = {107 -- 124}, year = {2024}, 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{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{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} } @inproceedings{ZippeliusHanssLiuetal.2020, author = {Zippelius, Andreas and Hanss, Alexander and Liu, E and Schmid, Maximilian and P{\´e}rez-Vel{\´a}zquez, Judith and Elger, Gordon}, title = {Comparing prediction methods for LED failure measured with Transient Thermal Analysis}, booktitle = {2020 21st International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-6049-8}, doi = {https://doi.org/10.1109/EuroSimE48426.2020.9152657}, year = {2020}, 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{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{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{SchmidHermannLiuetal.2022, author = {Schmid, Maximilian and Hermann, Joseph and Liu, E and Elger, Gordon}, title = {Correlation of Scanning Acoustic Microscopy and Transient Thermal Analysis to Identify Crack Growth in Solder Joints}, booktitle = {Proceedings of the Twenty First InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems: ITherm 2022}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-8503-6}, doi = {https://doi.org/10.1109/iTherm54085.2022.9899664}, year = {2022}, language = {en} } @inproceedings{ZippeliusStroblSchmidetal.2022, author = {Zippelius, Andreas and Strobl, Tobias and Schmid, Maximilian and Hermann, Joseph and Hoffmann, Alwin and Elger, Gordon}, title = {Predicting thermal resistance of solder joints based on Scanning Acoustic Microscopy using Artificial Neural Networks}, 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/ESTC55720.2022.9939465}, pages = {566 -- 575}, year = {2022}, 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} } @article{ZippeliusHanssSchmidetal.2022, author = {Zippelius, Andreas and Hanss, Alexander and Schmid, Maximilian and P{\´e}rez-Vel{\´a}zquez, Judith and Elger, Gordon}, title = {Reliability analysis and condition monitoring of SAC+ solder joints under high thermomechanical stress conditions using neuronal networks}, volume = {2022}, pages = {114461}, journal = {Microelectronics Reliability}, number = {129}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0026-2714}, doi = {https://doi.org/10.1016/j.microrel.2021.114461}, year = {2022}, abstract = {The thermo-mechanical fatigue of different SAC+ solders is investigated using transient thermal analysis (TTA) and predicted using artificial neural networks (ANN). TTA measures the thermal impedance and allows detection of solder cracks and delamination of material interfaces. LEDs soldered to printed circuit boards using seven different solders were aged within passive air-to-air temperature shock tests with TTA measurements every 50 cycles with the increase of the thermal resistance as failure criterium. A SnAgCuSb solder showed the best performance improvement over the SAC305 reference under the test conditions. In addition to standard evaluation by the cumulative failure-curve and Weibull plot, new approaches for reliability assessment are investigated to assess the reliability of the solder joint of the individual LEDs. A hybrid approach to predict failures in the solder joints of the individual LEDs during accelerated stress testing is set-up which processes the TTA data using artificial neural networks with memory, specifically LSTM, where the memory allows full use of the measurement history. Two ANN approaches, regression and classification, are used. Both approaches are shown to be quite accurate. The greater information gained from the regression approach requires more processing using external knowledge of the problem requirements, whereas the categorical approach can be more directly implemented. The results demonstrate the advantages of integrated approaches for assessment of the remaining useful life of solder joints.}, 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} } @article{HanssSchmidLiuetal.2015, author = {Hanss, Alexander and Schmid, Maximilian and Liu, E and Elger, Gordon}, title = {Transient thermal analysis as measurement method for IC package structural integrity}, volume = {24}, pages = {068105}, journal = {Chinese Physics B}, number = {6}, publisher = {IOP Publishing}, address = {Bristol}, issn = {2058-3834}, doi = {https://doi.org/10.1088/1674-1056/24/6/068105}, year = {2015}, 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} }