@inproceedings{MTMT:36355274,
	title = {Improved Thermal Transient Testing of GaN Devices Manufactured with Various Construction Principles},
	url = {https://m2.mtmt.hu/api/publication/36355274},
	author = {Ress, Sándor László and Farkas, Gábor and Darwish, Mahmoud Ibrahim Azmi and Kerecsen Istvánné Rencz, Márta and Sárkány, Zoltán},
	booktitle = {2025 31st International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)},
	doi = {10.1109/THERMINIC65879.2025.11216958},
	unique-id = {36355274},
	abstract = {Thermal transient tests are indispensable for characterizing electronic systems such as packaged devices, modules or subassemblies. They have two related targets, one is yielding peak system temperatures at various powering, the other is to provide partial thermal resistances and structural details near to the active devices. The latter became more difficult with advanced switching devices of extreme low ON resistance, such as GaN HEMTs. The paper first presents what are the temperature sensitive structures and heaters in GaN devices. Then it is explained how thermal impedances and structure functions are influenced by the series resistances in HEMT packages and the hosting printed boards. In order to eliminate from the calculations of thermal descriptors those external resistances that distort the test results; an analytical methodology has been developed. The method is verified and evaluated by measurements on actual samples, and the restoring of true thermal properties is demonstrated. © 2025 IEEE.},
	year = {2025},
	orcid-numbers = {Ress, Sándor László/0000-0003-4611-0718; Kerecsen Istvánné Rencz, Márta/0000-0003-4183-3853}
}

@article{MTMT:35133146,
	title = {Analytical Prediction of the Thermal Behavior of Semiconductor Power Devices from Room-Temperature I–V Measurements},
	url = {https://m2.mtmt.hu/api/publication/35133146},
	author = {Ress, Sándor László and Farkas, Gabor and Kerecsen Istvánné Rencz, Márta},
	doi = {10.3390/en17122931},
	journal-iso = {ENERGIES},
	journal = {ENERGIES},
	volume = {17},
	unique-id = {35133146},
	issn = {1996-1073},
	abstract = {The thermal characterization of power devices is an inevitable task in the industry. Thermal transient testing is one of the major tools for this characterization, as it is not only capable of giving information about the actual thermal parameters but may also reveal the root cause of potential device failures. The testing may occur on single packages or modules on a dedicated standard test bench, or “in situ”, in an actual assembly. The testing process itself is very fast in both cases, on the order of seconds, but the transient measurement needs to be preceded by a calibration step to determine the temperature dependence of a temperature-sensitive parameter (TSP) of the semiconductor device. This may require a long time, as the device has to be measured at many stabilized temperatures, which in the case of power devices may take hours. It also has to be considered that, especially in “in situ” measurements, reaching the highest device temperatures of power devices may even damage other parts of the surrounding electronics. Moreover, the temperature distribution inside a module will be different at calibration time than during operation with the same junction temperature, as bond wires and copper traces do not reach the chip temperature in the latter case. This paper presents a methodology that can be used to replace the lengthy measurement of one parameter at many temperatures with a fast single I–V characteristics measurement at room temperature. Physics-based calculations assign a unique temperature-sensitive parameter to each item of interest in the system. After the presentation of the theoretical background, the usability of the method is demonstrated by verifying measurements on silicon power devices. © 2024 by the authors.},
	keywords = {CALIBRATION; parameter estimation; room temperature; Temperature distribution; Transient analysis; Sensitive parameter; Semiconductor junctions; Analytical predictions; Thermal transient measurements; Thermal transient measurement; P-n junction; power semiconductor devices; Thermal behaviours; temperature sensitive; Power devices; pn junction; forward voltage; forward voltage; temperature sensitive parameters; Temperature sensitive parameter; temperature-to-voltage mapping; temperature-to-voltage mapping},
	year = {2024},
	eissn = {1996-1073},
	orcid-numbers = {Ress, Sándor László/0000-0003-4611-0718; Kerecsen Istvánné Rencz, Márta/0000-0003-4183-3853}
}

@inproceedings{MTMT:34448273,
	title = {Thermal Transient Tests with Programmed Powering on Wide Bandgap Power Devices of Non-Monotonous and Time-Variant Characteristics},
	url = {https://m2.mtmt.hu/api/publication/34448273},
	author = {Ress, Sándor László and Sárkány, Zoltán and Kerecsen Istvánné Rencz, Márta and Farkas, Gábor},
	booktitle = {Proceedings of the 29th International Workshop on THERMal INvestigation of ICs and Systems (THERMINIC'23)},
	doi = {10.1109/THERMINIC60375.2023.10325869},
	unique-id = {34448273},
	abstract = {Thermal transient testing of semiconductor devices needs a well-defined power level for heating and proper data acquisition for recording the change of a thermally sensitive device parameter. While the latter is fully solved by up-to-date thermal testers, power level setting is typically limited to forcing varying current levels on two pin devices, such as diodes. Other proposed methods need trials for setting the power and have poor stability.The paper presents a methodology for applying power in various test arrangements, on devices with three pins such as MOSFETs, IGBTs, BJTs and HEMTs. A simple analog circuitry is proposed which ensures thermally and electrically stable powering and an exact operating voltage and current.Several simulation and measurement experiments prove that a novel solution based on fast drain-source voltage change at constant current ensures optimal powering in reliability tests and short electric distortion in transient tests. © 2023 IEEE.},
	keywords = {wide band gap semiconductors; high electron mobility transistors; Data acquisition; Energy gap; MOSFETS; Transient analysis; Thermal transient testing; Thermal transient testing; Reliability testing; Reliability testing; well testing; MOSFET; High power; High power; Wide-band-gap semiconductors; Drain current; Power levels; Power MOSFET; MOS-FET; Wide-band-gap semiconductor; Thermal transients; Transient tests},
	year = {2023},
	orcid-numbers = {Ress, Sándor László/0000-0003-4611-0718; Kerecsen Istvánné Rencz, Márta/0000-0003-4183-3853}
}

@inproceedings{MTMT:33698131,
	title = {Accelerating the Thermal Transient Testing by a Novel Temperature Sensitive Parameter Calibration Method based on I-V Characteristic Measurement},
	url = {https://m2.mtmt.hu/api/publication/33698131},
	author = {Ress, Sándor László and Sarkany, Zoltan and Farkas, Gabor and Kerecsen Istvánné Rencz, Márta},
	booktitle = {Proceedings of the 28th International Workshop on THERMal INvestigation of ICs and Systems (THERMINIC'22)},
	doi = {10.1109/THERMINIC57263.2022.9950658},
	unique-id = {33698131},
	abstract = {Thermal characterisation of each large power module or assembly is inevitable in the industry. Thermal transient testing provides not only generic thermal parameters but also the root causes of potential failures. The major bottleneck in this process is the long time needed for the calibration of a thermally sensitive parameter of the semiconductor devices, opposed to the actual measurement time which is a few tens of seconds. The article presents a methodology which replaces the lengthy measurement of a parameter at many temperatures by a complete current-voltage sweep fulfilled below a second and some calculations based on semiconductor physics. The method also may predict the high temperature behaviour of wide band gap semiconductor components, needed for lifetime estimation.},
	keywords = {THERMODYNAMICS; wide band gap semiconductors; In situ testing; Thermal transient testing; Engineering, Electrical & Electronic},
	year = {2022},
	pages = {1-4},
	orcid-numbers = {Ress, Sándor László/0000-0003-4611-0718; Kerecsen Istvánné Rencz, Márta/0000-0003-4183-3853}
}

@inproceedings{MTMT:32801699,
	title = {On the Correction of the Effects of Electrical Transients in the Measured Thermal Transients},
	url = {https://m2.mtmt.hu/api/publication/32801699},
	author = {Ress, Sándor László and Sárkány, Zoltán and Farkas, G. and Kerecsen Istvánné Rencz, Márta},
	booktitle = {2021 IEEE 23rd Electronics Packaging Technology Conference (EPTC)},
	doi = {10.1109/EPTC53413.2021.9663887},
	unique-id = {32801699},
	abstract = {Thermal transient testing is a principal methodology for the structural analysis of power assemblies and for the estimation of peak temperatures in the system which influence lifetime. For both purposes the key parameter is the starting temperature of the transient, the measurement of which is hindered by several electric effects that distort the early section of the measured thermal transients. These effects can be physically shortened and partly diminished with proper test planning. On the other hand, the distorted section can be reconstructed by physical considerations, using appropriate extrapolation or a simulation based on the well-known physical structure of the semiconductor chip and its attachment.This article deals with the physical and procedural correction of these electrical effects in case of different devices.},
	year = {2021},
	pages = {399-404},
	orcid-numbers = {Ress, Sándor László/0000-0003-4611-0718; Kerecsen Istvánné Rencz, Márta/0000-0003-4183-3853}
}

@inproceedings{MTMT:3378564,
	title = {LED Characterization within the Delphi4LED Project},
	url = {https://m2.mtmt.hu/api/publication/3378564},
	author = {Farkas, Gábor and Lajos, Gaál and Bein, Márton and Poppe, András and Ress, Sándor László and Kerecsen Istvánné Rencz, Márta},
	booktitle = {Proceedings of The 17th Intersociety Conference on Thermomechanical Phenomena in Electronic Systems (ITHERM'18)},
	doi = {10.1109/ITHERM.2018.8419602},
	unique-id = {3378564},
	abstract = {The European Delphi4LED consortium intensively works on measurement, modeling and simulation techniques to cope with the lack of standardized methodologies to describe the strongly temperature and current dependent characteristics of  LEDs. The paper presents some of the efforts and results in 
		 making the lighting design of luminaires an automated, model based process; similarly to the design practice in electronics. To achieve this target, validated and standardized multiphysics LED models are needed. 
		
		In this paper results in comparing standard LED measurement methods and the realized upgraded testing and modeling procedures are shown, as the authors see it after one and half year of intensive collaboration in the subject.},
	year = {2018},
	pages = {262-271},
	orcid-numbers = {Poppe, András/0000-0002-9381-6716; Ress, Sándor László/0000-0003-4611-0718; Kerecsen Istvánné Rencz, Márta/0000-0003-4183-3853}
}

@inproceedings{MTMT:3285479,
	title = {Measurement issues in LED characterization for Delphi4LED style combined electrical-optical-thermal LED modeling},
	url = {https://m2.mtmt.hu/api/publication/3285479},
	author = {Hantos, Gusztáv and Hegedüs, János and Bein, Márton and L, Gaál and Farkas, Gábor and Sárkány, Zoltán and Ress, Sándor László and Poppe, András and Kerecsen Istvánné Rencz, Márta},
	booktitle = {2017 IEEE 19th Electronics Packaging Technology Conference (EPTC)},
	doi = {10.1109/EPTC.2017.8277493},
	unique-id = {3285479},
	abstract = {Traditionally incandescent and fluorescent light sources were 
		mostly used in a single operation point and their relevant 
		characteristics was described by a few parameters in a 
		datasheet. The emitted light of LED products depends on 
		current and temperature heavily and the behavior of LEDs in 
		actual use can be predicted only by complex models of 
		physical roots. The paper summarizes the targets and 
		methodology of the European Delphi4LED project aiming the 
		elaboration of relevant measurements for identifying 
		parameters of electrical-optical-thermal LED models. 
		Measurement examples of high power LEDs are shown and the 
		state-of-art of the modeling efforts is demonstrated in case 
		studies. 
		
		The two-diode Spice-like electro-thermal-optical model of 
		LEDs is proposed to be extended with a serial resistor in the 
		branch describing the light emission.},
	year = {2017},
	orcid-numbers = {Hantos, Gusztáv/0000-0002-0401-2098; Hegedüs, János/0000-0003-4792-6225; Ress, Sándor László/0000-0003-4611-0718; Poppe, András/0000-0002-9381-6716; Kerecsen Istvánné Rencz, Márta/0000-0003-4183-3853}
}

@article{MTMT:3030623,
	title = {On the application of the vibrating Kelvin probe method for quality control of Cu(In,Ga)(Se,S)2 thin-film solar modules},
	url = {https://m2.mtmt.hu/api/publication/3030623},
	author = {T, Lavrennko and K, Marzinzig and T, Walter and Plesz, Balázs and Ress, Sándor László},
	doi = {10.1002/pip.2746},
	journal-iso = {PROG PHOTOVOLTAICS},
	journal = {PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS},
	volume = {24},
	unique-id = {3030623},
	issn = {1062-7995},
	year = {2016},
	eissn = {1099-159X},
	pages = {1554-1565},
	orcid-numbers = {Ress, Sándor László/0000-0003-4611-0718}
}

@inproceedings{MTMT:2966156,
	title = {Possibilities and Challenges of Thermal Transient Testing as a Characterization Method for Photovoltaic Devices},
	url = {https://m2.mtmt.hu/api/publication/2966156},
	author = {Plesz, Balázs and Szabó, Péter Gábor and D., Dudola and Hantos, Gusztáv and Ress, Sándor László},
	booktitle = {31st European Photovoltaic Solar Energy Conference and Exhibition},
	doi = {10.4229/EUPVSEC20152015-5AV.6.31},
	unique-id = {2966156},
	abstract = {The thermal behaviour of mass production terrestrial solar modules is a somehow neglected but very important issue of photovoltaics. Despite its significant influence on the power generation, the thermal properties of solar modules are mostly not taken into account in daily applications. In recent literature thermal transient testing was suggested as a possible solution to proper thermal characterization of photovoltaic devices. In this paper we give a short overview on the known issues of the thermal transient testing of photovoltaic devices and address the issue of the variation of the structure function at different heating currents as well as the influence of the initial degradation of amorphous solar cells on the measurement results. It is shown that for small current densities the increasing forward driving current (i.e. the heating current) can have a strong influence on the size of the active area that on the other hand determines the volume of the heat path. Due to this an increasing heating current results in the decrease of the junction to ambient thermal resistance, with the thermal resistance converging to a minimum value at high heating currents. The phenomenon was also investigated by Kelvin probe potential mapping. In addition it was investigated how the initial degradation of amorphous silicon solar cells effect the results of the thermal transient measurement.},
	year = {2015},
	pages = {2031-2034},
	orcid-numbers = {Szabó, Péter Gábor/0000-0001-7601-743X; Hantos, Gusztáv/0000-0002-0401-2098; Ress, Sándor László/0000-0003-4611-0718}
}

@inproceedings{MTMT:2767104,
	title = {Issues of Thermal Transient Testing on Photovoltaic Modules},
	url = {https://m2.mtmt.hu/api/publication/2767104},
	author = {Plesz, Balázs and Ress, Sándor László and Szabó, Péter Gábor and Hantos, Gusztáv and D., Dudola},
	booktitle = {20th International Workshop on THERMal INvestigation of ICs and Systems (THERMINIC'14)},
	doi = {10.1109/THERMINIC.2014.6972511},
	unique-id = {2767104},
	keywords = {SOLAR-CELL},
	year = {2014},
	pages = {1-4},
	orcid-numbers = {Ress, Sándor László/0000-0003-4611-0718; Szabó, Péter Gábor/0000-0001-7601-743X; Hantos, Gusztáv/0000-0002-0401-2098}
}