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[IEEE 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) - Berlin, Germany (2019.6.23-2019.6.27)] 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) - Manipulation of Biomolecules Into Nanogap by Plasmonic Optical Excitation for Highly Sensitive Biosensing
摘要： This paper presents an apparatus and methodology for an advanced accelerated power cycling test of insulated-gate bipolar transistor (IGBT) modules. In this test, the accelerated power cycling test can be performed under more realistic electrical operating conditions with online wear-out monitoring of tested power IGBT module. The various realistic electrical operating conditions close to real three-phase converter applications can be achieved by the simple control method. Further, by the proposed concept of applying the temperature stress, it is possible to apply various magnitudes of temperature swing in a short cycle period and to change the temperature cycle period easily. Thanks to a short temperature cycle period, test results can be obtained in a reasonable test time. A detailed explanation of apparatus such as configuration and control methods for the different functions of accelerated power cycling test setup is given. Then, an improved in situ junction temperature estimation method using on-state collector–emitter voltage VC E O N and load current is proposed. In addition, a procedure of advanced accelerated power cycling test and test results with 600 V, 30 A transfer molded IGBT modules are presented in order to verify the validity and effectiveness of the proposed apparatus and methodology. Finally, physics-of-failure analysis of tested IGBT modules is provided.
关键词： insulated-gate bipolar transistor module,physics-of-failure,power cycling test,lifetime model,Failure mechanism,reliability
更新于2025-09-23 15:19:57
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The roles of stress in the thermal shock failure of YSZ TBCs before and after laser remelting
摘要： In order to reveal the roles of stress in the thermal shock failure of thermal barrier coatings (TBCs), yttria-stabilised zirconia (YSZ) TBCs were prepared via atmospheric plasma spraying and then remelted by a laser remelting process. Subsequently, thermal cycling tests of the as-sprayed YSZ TBCs and remelted YSZ TBCs were carried out at 1100 °C. The thermal shock failure mechanism of the two TBCs was investigated comparatively from the perspective of stress, i.e., phase transformation stress of ceramic coating, growth stress and thermal mismatch stress generated by thermally grown oxide (TGO). The results showed that, compared with the as-sprayed YSZ TBCs, there was no m-ZrO2 in the remelted YSZ TBCs, which avoided the ceramic coating phase transformation stress produced by the transformation between m-ZrO2 and t-ZrO2 during thermal cycling. Therefore, the thermal shock failure mode of the as-sprayed YSZ TBCs was severe buckling driving delamination, while that of the remelted YSZ TBCs was slight edge delamination. In addition, the TGO growth stress and the thermal mismatch stress between the TGO and the bonding coating were reduced by the laser remelting treatment, leading to the spallation tendency of YSZ TBCs was decreased. Consequently, the remelted YSZ TBCs exhibited superior thermal shock resistance to the as-sprayed YSZ TBCs. Therefore, the phase transformation stress, growth stress and thermal mismatch stress determined the thermal shock failure mode and thermal shock life of these two YSZ TBCs.
关键词： Stress,Laser remelting,TGO,Thermal shock failure mechanism,TBCs
更新于2025-09-23 15:19:57
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[IEEE 2019 International Conference on Electrical, Electronics and Computer Engineering (UPCON) - ALIGARH, India (2019.11.8-2019.11.10)] 2019 International Conference on Electrical, Electronics and Computer Engineering (UPCON) - A Study on the Influence of Open Circuit Voltage (Voc) and Short Circuit Current (Isc) on Maximum Power Generated in a Photovoltaic Module/Array
摘要： A technique is described, to efficiently evaluate the reliability of an RF semiconductor device when several different mechanisms contribute simultaneously to its wearout. This is of interest for present-day GaN HEMT devices because symptoms of several simultaneous degradation mechanisms have been reported widely. The technique involves first finding DC parameters that are “signatures” of each mechanism. Then, separate DC-stress lifetests are performed to find the degradation rates for the signature parameters, at several temperatures, and the corresponding Arrhenius curves. Next, an RF-stress lifetest (with only one stress condition) is performed, while monitoring all of the signature parameters and the RF performance. This is utilized to determine the “scaling factors” between the rates of change in the DC lifetests and the rates of change in the RF application. Applying these scaling factors to the original Arrhenius curves gives an “overall” Arrhenius plot for the RF application with several different lines, for the different degradation mechanisms. The technique can be extended to further degradation mechanisms, by conducting further DC and RF lifetests while monitoring appropriate signature parameters.
关键词： semiconductor device reliability,lifetesting,gallium nitride,HEMTs,Failure analysis
更新于2025-09-23 15:19:57
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Cuff Failure of Spiral-Filled Polyvinyl Chloride Endotracheal Tube Immediately after Tracheal Intubation Using a Channeled Videolaryngoscope (Pentax Airway Scope)
摘要： We report on a case of mechanical damage to the spiral-?lled polyvinyl chloride endotracheal tube that occurred shortly after tracheal intubation using a channeled videolaryngoscope (Pentax airway scope). We also found this problem in two other cases among 350 neurosurgery patients over the past 5 years. Prior to intubation, we did not observe any defect in the cu?. However, the cu? could not be ?lled with air immediately after the intubation. Anesthesiologists should be aware that, during tracheal intubation using an airway scope, friction between the endotracheal tube and inner surface of the introducer might result in sudden rupture of the cu?.
关键词： videolaryngoscope,endotracheal tube,tracheal intubation,cuff failure,mechanical damage
更新于2025-09-23 15:19:57
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Dynamic Response-Based LEDs Health and Temperature Monitoring
摘要： this paper presents a number of novel methods to measure the junction temperature and to estimate the health of gallium nitride light-emitting diodes (LEDs). The methods are based on measurements of the dynamic impedance and optical output. Our experimental analysis reveals temperature sensitive parameters of the electrical and optical responses. Moreover, a correlation between the non-radiative current characterizing the defects in the active region and the small-signal impedance is demonstrated. The demonstrated methods can be applied to enhance existing techniques. The temperature-monitoring derived dependencies also build a foundation for advanced in-field monitoring health of the LEDs and for prediction of imminent failures using the infrastructure of visible light communication systems. Such models are valuable for predictive maintenance.
关键词： smart driver,failure modes,temperature,impedance,OWC,electrical response,optical response,defects,LED,reliability
更新于2025-09-23 15:19:57
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P1757Laser lead extraction in patients with venous stenosis or occlusion
摘要： Mechanical characteristics of the left ventricle (LV) may be encoded in cardiac acoustic signatures within low frequency ranges. We aimed to characterise i) acoustic features in the frequency domain in subjects with normal LV function (Group 1) and patients with heart failure with reduced ejection fraction (HFREF) indicated for cardiac resynchronisation therapy (CRT, Group 2) and ii) their relationship with aortic velocity time integral (VTI) with respect to signal to noise ratio (SNR) during atrio-ventricular (AV) optimisation of CRT. 15-seconds segments of heart sounds obtained from electronic (e-) stethoscope recordings of subjects in Group 1 (N?21), Group 2 (N?28), and 4 subjects undergoing AV optimization of CRT were subjected to a novel signal processing method to detect S1 and S2 sounds envelopes and extract frequency-domain acoustic features from the detected envelopes. During AV optimization of CRT (pacing at 90bpm), aortic VTI and EA duration were measured with Doppler on echocardiography from a range of paced AV delays (PAVD). The optimal PAVD was found at the highest aortic VTI with the best EA duration and pattern for LV ?lling. The SNR of the acoustic features were calculated by dividing the range of signals across all the tested PAVD by the average size of the standard error of mean (SEM) (the noise) at each PAVD. Results: 1) Two frequency-domain features extracted from the S1 envelopes (AV_S1_B and AV_S1_C) were higher in Group 1 compared to Group 2 (?g. 1). No difference was found in the same features extracted from the S2 envelopes (AV_S2_B and AV_S2_C) between the 2 groups. 2) During AV optimization of CRT, AV_S1_C correlated with aortic VTI in subjects with high SNR (e.g. SNR?7.8: N?10, r?0.67, p?0.03, 2-tailed) but not in those with low SNR (e.g. SNR?3.9: N?7, r?-0.322, p?0.48). 3) In the subject with the highest SNR (7.8), the PAVD at the highest value of AV_S1_C coincides with the optimal PAVD derived from echocardiography (?g. 2). Conclusion: e-Cardiac acoustics offer a potential novel method to diagnose HFREF and optimize AVD in CRT. Future studies to con?rm the current ?ndings and improve the SNR of this method are needed for clinical utility.
关键词： heart failure,cardiac resynchronisation therapy,signal to noise ratio,cardiac acoustics,aortic velocity time integral
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE International Ultrasonics Symposium (IUS) - Glasgow, United Kingdom (2019.10.6-2019.10.9)] 2019 IEEE International Ultrasonics Symposium (IUS) - Tiled Large Element 1.75D Aperture with Dual Array Modules by Adjacent Integration of PIN-PMN-PT Transducers and Custom High Voltage Switching ASICs
摘要： A technique is described, to efficiently evaluate the reliability of an RF semiconductor device when several different mechanisms contribute simultaneously to its wearout. This is of interest for present-day GaN HEMT devices because symptoms of several simultaneous degradation mechanisms have been reported widely. The technique involves first finding DC parameters that are “signatures” of each mechanism. Then, separate DC-stress lifetests are performed to find the degradation rates for the signature parameters, at several temperatures, and the corresponding Arrhenius curves. Next, an RF-stress lifetest (with only one stress condition) is performed, while monitoring all of the signature parameters and the RF performance. This is utilized to determine the “scaling factors” between the rates of change in the DC lifetests and the rates of change in the RF application. Applying these scaling factors to the original Arrhenius curves gives an “overall” Arrhenius plot for the RF application with several different lines, for the different degradation mechanisms. The technique can be extended to further degradation mechanisms, by conducting further DC and RF lifetests while monitoring appropriate signature parameters.
关键词： lifetesting,semiconductor device reliability,gallium nitride,Failure analysis,HEMTs
更新于2025-09-23 15:19:57
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Monitoring ammonia through cavity-enhanced absorption spectroscopy
摘要： We present the design of a dual failure protected elastic optical network (EON) for different sharing capabilities of protection lightpaths. Routing and spectrum assignment (RSA) is considered for such a network so as to minimize the maximum number of frequency slots (FSs) used. The key principles for protection resource sharing among the first and the second protection lightpaths are identified for dedicated 1:1:1, mixed 1:1:1, 1+1:1, and 1+1+1 protection. Both integer linear programming (ILP) models and spectrum window plane (SWP)-based heuristic algorithms are proposed for RSA in dual failure protected EONs. Simulation results indicate that, apart from being efficient, the proposed SWP-based heuristic algorithm not only performs close to the ILP model but also does much better than a benchmark adaptive routing algorithm. We find that 1:1:1 protection technique performs better in terms of the maximum number of FSs used and the spare capacity redundancy than both the 1+1:1 and 1+1+1 techniques. In addition, the mixed 1:1:1 case outperforms the dedicated 1:1:1 case both in minimizing the maximum number of link FSs used and its spare capacity redundancy.
关键词： dual failure,1+1+1,Elastic optical network (EON),ILP model,spectrum window plane (SWP),dedicated 1:1:1,1+1:1,mixed 1:1:1
更新于2025-09-23 15:19:57
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Fatigue behavior improvements of laser-induction hybrid welded S690QL steel plates
摘要： In this paper, the improvements of fatigue performances of S690QL steel welded by laser-induction hybrid welding (LIHW) method were performed, mainly through the infrared imaging device to obtain the weld thermal cycle, fatigue machine to test the fatigue strength and scanning electron microscope to observe the fracture morphology. In fatigue tests, tension-tension fatigue loading and stress ratio R = 0.1 was selected. The LIHW fitted S-N curves were derived. It was found that the cracks with symmetrical grooves were initiated at the weld center (WC), while the single-laser welding (SLW) fatigue samples were fractured at the WC. However, the LIHW samples were finally fractured near heat-affected zone (HAZ). The fracture morphology of fatigue samples with stress amplitude of 108 MPa and 144 MPa were further selected to analysis. Due to different degree of defects or stress concentration, and different welding heat input absorption ability and cooling rate, in sudden fracture region, SLW fatigue samples mainly contained the brittle transient failure mode, LIHW fatigue samples mainly showed a ductile failure mode. It can thus be concluded that the LIHW method could improve the fatigue performance of S690QL steel joints.
关键词： Transient failure mode,Single-laser welding,Cracks,Laser-induction hybrid welding,Fatigue strength
更新于2025-09-23 15:19:57
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Robust crystalline silicon photovoltaic module (c-Si PVM) for the tropical climate: future facing the technology
摘要： A critical impediment to the adoption and sustained deployment of crystalline silicon photovoltaic modules (c-Si PVMs) in the tropical climate is the accelerated degradation of their interconnections. At 40.7% c-Si PVM interconnect failure rate worldwide and significantly higher in the tropics. A review of impact of elevated ambient temperature operations on accelerated interconnection degradation is critical to achieving the system’s sustainability and reliability up to the 25-year design lifespan. This study reviews critical module’s operational parameters to advise on the future facing creation of robust module for the tropical region. Key areas reviewed include manufacturing process, solar cell efficiency, interconnection technology and R&D parameters. The review discusses the state-of-the-art in c-Si PVM interconnection technologies and propose back-junction-back-contact (BJ-BC) cell technology for adoption in the manufacture of the next generation of robust c-Si PVM for the tropics. The review findings provide insight into the future facing the robust c-Si PVM technology that is useful to the module design engineers.
关键词： Crystalline silicon photovoltaic module,elevated ambient temperature,interconnection failure,module life span
更新于2025-09-23 15:19:57