TRUMPF (Poland)

Impedance matching circuits are used in plasma processing systems to adjust a complex impedance of plasma chamber to standardized value $- 50 \Omega$. However, this unusual application introduces several challenges for impedance matching circuit, like: wide changes of load impedance related to plasma ignition or changes of load impedance in accordance to power delivered to the vacuum chamber. On top of that, there is a distinct drive to reduce time required to reach nominal VSWR to lowest possible value. Thus, to address this issue a proposal of Iterative Learning Control (ILC) algorithm for impedance matching circuit was introduced.

Peu après le meurtre de George Floyd, la publication d’une tribune appelant à l’armée dans les pages opinions du New York Times entraîne une vive réaction d’une partie de la rédaction du journal qui s’étend à l’ensemble de la presse mainstream américaine. Elle provoqua la démission du directeur éditorial et de plusieurs de ses collègues ainsi que la remise en question par son directeur général de la politique éditoriale traditionnelle du journal, marquée jusque-là par l’ouverture au débat et à la controverse. Elle appelle à une évolution des normes journalistiques dans un paysage de guerres culturelles à l’heure de la cancel culture.

The main drawback of any Design for Reliability methodology is lack of easy accessible reliability models, prepared individually for each critical component. In this paper, a reliability model for SiC power MOSFET in SOT – 227 B housing, subjected to power cycling, is presented. Discussion covers preparation of Accelerated Lifetime Test required to develop such reliability model, analysis of semiconductor degradation progress, samples post-failure analysis and identification of reliability model parameters. Such model may be further used for failure prognostics or useful lifetime estimation of High Performance Power Supplies.

Nowadays, end users of power electronic converters require not only the best quality, excellent performance and high efficiency, but also, as the most important parameter, reliability [1]. In the case of power semiconductors, a very essential element of each power converter, the main stressor is junction temperature (maximum value and amplitude of temperature swing), since it greatly accelerates degradation mechanisms, which significantly reduces device lifetime [2]. These facts lead to the obvious conclusion that the temperature of power semiconductors should be measured during start-up and qualification testing of newly developed power supplies, to assess stress levels to which these critical components are subjected. In the case of power supplies operating at high power levels (30 - 120 kW) and high frequencies (4 - 13.56 MHz) even simple temperature measurement becomes a challenge [3]. This paper presents the design process of a robust data logging system, immune to the presence of a heavily distorted electromagnetic field, and its performance in comparison to commercial solutions.

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