• Title/Summary/Keyword: junction temperature

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Thermal Stress at the Junction of Skirt to Head in Hot Pressure Vessel (고온 수직형 압력용기 Skirt 부의 열응력에 관한 연구)

  • 한명수;한종만;조용관
    • Journal of Welding and Joining
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    • v.16 no.2
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    • pp.111-121
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    • 1998
  • It is well recognized that a excessive temperature gradient from the junction of head to skirt in axial direction in a hot pressure vessel can cause unpredicted high thermal stress at the junction and/or in axial direction of a skirt. this thermal stress resulting from axial thermal gradient may be a major cause of unsoundness of structural integrity. In case of cyclic operation of hot pressure vessels, the thermal stress becomes one of the primary design consideration because of the possibility of fracture as a result of cyclic thermal fatigue and progressively incremental plastic deformation. To perform thermal stress analysis of the junction and cylindrical skirt of a vessel, or, at least, to inspect quantitatively the magnitude and effect of thermal stress, the temperature profile of the vessel and skirt must be known. This paper demonstrated the temperature distribution and thermal stress analysis for the junction of skirt to head using F.E. analysis. Effect of air pocket in crotch space was quantitatively investigated to minimize the temperature gradient causing the thermal stress in axial direction. Effect of the skirt height on thermal stresses was also studied. Analysis results were compared with theoretical formulas to verify th applicability to the strength calculation in design field.

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Junction Temperature Prediction of IGBT Power Module Based on BP Neural Network

  • Wu, Junke;Zhou, Luowei;Du, Xiong;Sun, Pengju
    • Journal of Electrical Engineering and Technology
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    • v.9 no.3
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    • pp.970-977
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    • 2014
  • In this paper, the artificial neural network is used to predict the junction temperature of the IGBT power module, by measuring the temperature sensitive electrical parameters (TSEP) of the module. An experiment circuit is built to measure saturation voltage drop and collector current under different temperature. In order to solve the nonlinear problem of TSEP approach as a junction temperature evaluation method, a Back Propagation (BP) neural network prediction model is established by using the Matlab. With the advantages of non-contact, high sensitivity, and without package open, the proposed method is also potentially promising for on-line junction temperature measurement. The Matlab simulation results show that BP neural network gives a more accuracy results, compared with the method of polynomial fitting.

Effect of the Epoxy Mold on the Thermal Dissipation Behavior of LED Package (LED 패키지에서 에폭시 몰드가 방열특성에 미치는 영향)

  • Bang, Young-Tae;Moon, Cheol-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.2
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    • pp.1-7
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    • 2012
  • LED package with 4[mm]-height mold was manufactured and the surface temperature was measured directly using both thermocouple and thermal infrared (IR) camera. FVM simulation was conducted to estimate the surface temperature of the same LED package under the same condition, by which the accuracy of the simulation was secured. Then, the effects of the height and thermal conductivity of the mold on the junction temperature of the LED package were investigated by FVM simulation. The results showed that the junction temperature decreased by 10[$^{\circ}C$] when the mold height was 3~5[mm], but the thermal conductivity of the mold didn't affect the junction temperature significantly.

Study on junction temperature characteristics of TO-CAN laser diode for optimized screening tests (접합 온도를 고려한 TO-CAN 레이저 다이오드의 Screening 조건 연구)

  • 이동수
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.6
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    • pp.126-129
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    • 2002
  • To extract exact screening conditions of TO-CAN laser diode, junction temperature during screening was investigated. Temperature increase due to thermal resistance was measured and compared with theoretical calculation. Injection current dependence of injection temperature was derived with good agreement with experimental data and used to obtain accurate screening conditions.

Generation Efficiency and Thermal Performance of a Thermoelectric Generator with a High Power Electronic Component (고전력 전자소자에서 열전생성기의 생성효율과 열적성능)

  • Kim, Kyoung-Joon
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.1
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    • pp.51-56
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    • 2012
  • This paper reports the generation efficiency and the thermal performance of a thermoelectric generator (TEG) harvesting energy from the waste heat of high power electronic components. A thermoelectric (TE) model containing thermal boundary resistances is used to predict generation efficiency and junction temperature of a high power electronic component. The predicted results are verified with measured values, and the discrepancy between prediction and measurement is seen to be moderate. The verified TE model predicts generation efficiencies, junction temperatures of the component, and temperature differences across a TEG at various source heat flows associated with various electrical load resistances. This study explores effects of the load resistance on the generation efficiency, the temperature difference across a TEG, and the junction temperature.

Progressive Inelastic Deformation Characteristics of Cylindrical Structure with Plate-to-Shell Junction Under Moving Temperature Front

  • Lee, Hyeong-Yeon;Kim, Jong-Bum
    • Journal of Mechanical Science and Technology
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    • v.17 no.3
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    • pp.400-408
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    • 2003
  • A study on the progressive inelastic deformation behavior of the 316 L stainless steel cylindrical structure with plate-to-shell junction under moving temperature front was carried out by structural test and analysis. The structural test intends to simulate the thermal ratcheting behavior occurring at the reactor baffle of the liquid metal reactor as free surface of hot sodium pool moves up and down under plant transients. The thermal ratchet load that heats the specimen up to 550$^{\circ}C$ was applied repeatedly and residual deformation was measured. The thermal ratcheting test was carried out with two types of cylindrical structures, one with plate to-shell junction and the other without the junction to investigate the effects of the geometric discontinuities on the global ratcheting deformation. The temperature distributions of the test specimens were measured and were used for the ratcheting analysis. The ratchet deformations were analyzed with the constitutive equation of the non-linear combined hardening model. The analysis results were in good agreement with those of the structural tests.

Junction Temperature of Quantum Dot Laser Diodes Depending on the Mesa Depth (양자점 레이저 다이오드의 식각 깊이에 따른 접합온도 측정)

  • Jeong, Jung-Hwa;Han, Il-Ki;Lee, Jung-Il
    • Journal of the Korean Vacuum Society
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    • v.17 no.6
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    • pp.555-559
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    • 2008
  • Junction temperature of quantum dot laser diodes is investigated by utilizing forward voltage-temperature method. In the case of ridge type laser diodes with deep mesa the increasing rate of junction temperature to current is about 0.05 K/mA, while in the case of shallow mesa the increasing rate is about 0.07 K/mA. It is explained that the relatively low increasing rate in the deep mesa results from the heat expansion to the lateral direction of mesa.

Multi-junction thermocouple for temperature gradient measurements (온도구배 측정용 다중접점 열전대)

  • Kim, Yong-Gyoo;Gam, Kee-Sool
    • Journal of Sensor Science and Technology
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    • v.4 no.2
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    • pp.3-6
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    • 1995
  • Type K thermocouples having multi-junction for measuring the temperature gradient of the furnace were fabricated. The obtained results on the temperature gradient of the electric furnace maintained at $800^{\circ}C$ were consistent with those for the reference grade type S thermocouple, which was carefully calibrated, within the permitted error limit of the type K thermocouple. It was suggested that noble metal multi-junction thermocouples be suitable for more accurate temperature gradient measurements.

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Electron Tunneling Characteristics of PtSi-nSi Junctions according to Temperature Variations (온도변화에 따른 백금 실리사이드-엔 실리콘 접합의 전자 터널링 특성)

  • 장창덕;이정석;이광우;이용재
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.87-91
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    • 1998
  • In this paper, We analyzed the current-voltage characteristics with n-type silicon substrates concentration and temperature variations (Room temperature, 50$^{\circ}C$, 75$^{\circ}C$) in platinum silicide and silicon junction. The electrical parameters of measurement are turn-on voltage, saturation current, ideality factor, barrier height, dynamic resistance in forward bias and reverse breakdown voltage according to variations of junction concentration of substrates and measurement temperature variations. As a result, the forward turn-on voltage, reverse breakdown voltage, barrier height and dynamic resistance were decreased but saturation currents and ideality factor were increased by substrates increased concentration variations in platinum silicide and n-silicon junction. In increased measurement temperature (RT, 50$^{\circ}C$, 75$^{\circ}C$), the extracted electrical parameter values of characteristics were rises by increased temperature variations according to the forward and reverse bias.

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Design of Super-junction TMOSFET with Embedded Temperature Sensor

  • Lho, Young Hwan
    • Journal of IKEEE
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    • v.19 no.2
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    • pp.232-236
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    • 2015
  • Super-junction trench MOSFET (SJ TMOSFET) devices are well known for lower specific on-resistance and high breakdown voltage (BV). For a conventional power MOSFET (metal-oxide semiconductor field-effect transistor) such as trench double-diffused MOSFET (TDMOSFET), there is a tradeoff relationship between specific on-state resistance and breakdown voltage. In order to overcome the tradeoff relationship, a SJ TMOSFET structure is suggested, but sensing the temperature distribution of TMOSFET is very important in the application since heat is generated in the junction area affecting TMOSFET. In this paper, analyzing the temperature characteristics for different number bonding for SJ TMOSFET with an embedded temperature sensor is carried out after designing the diode temperature sensor at the surface of SJ TMOSFET for the class of 100 V and 100 A for a BLDC motor.