• Title/Summary/Keyword: Thermal Cycling Test

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Measurement of CTE Change in a Composite Laminate with Aging under Space Environment using Fiber Optic Sensors (광섬유센서를 이용한 우주환경하에서 복합재료 적층시편의 노화에 따른 열팽창계수변화 측정)

  • Gang,Sang-Guk;Gang,Dong-Hun;Kim,Cheon-Gon;Hong,Chang-Seon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.10
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    • pp.21-26
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    • 2003
  • In this research, the change of coefficient of thermal expansion (CTE) of graphite/epoxy composite laminate under space environment was measured using fiber optic sensors. Two fiber Bragg grating (FBG) sensors have been adopted for the simultaneous measurement of thermal strain and temperature. Low Earth Orbit (LEO) conditions with high vacuum, ultraviolet and thermal cycling environments were simulated in a thermal vacuum chamber. As a pre-test, a FBG temperature sensor was calibrated and a FBG strain sensor was verified through the comparison with the electric strain gauge (ESG) attached on an aluminun specimen at high and low temperature respectively. The change of the CTE in a composite laminate exposed to space environment was measured for intervals of aging cycles in real time. As a whole, there was no abrupt change of the CTE after 1000 aging cycles. After aging, however, the CTE decreased a Little all over the test temperature range. These changes are caused by outgassing, moisture desorption, matrix cracking etc.

A Study on Optimized Thermal Analysis Modeling for Thermal Design Verification of a Geostationary Satellite Electronic Equipment (정지궤도위성 전장품의 열설계 검증을 위한 최적 열해석 모델링 연구)

  • Jun Hyoung Yoll;Yang Koon-Ho;Kim Jung-Hoon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.4 s.235
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    • pp.526-536
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    • 2005
  • A heat dissipation modeling method of EEE parts, or semi-empirical heat dissipation method, is developed for thermal design and analysis an electronic equipment of geostationary satellite. The power consumption measurement value of each functional breadboard is used for the heat dissipation modeling method. For the purpose of conduction heat transfer modeling of EEE parts, surface heat model using very thin ignorable thermal plates is developed instead of conventional lumped capacity nodes. The thermal plates are projected to the printed circuit board and can be modeled and modified easily by numerically preprocessing programs according to design changes. These modeling methods are applied to the thermal design and analysis of CTU (Command and Telemetry Unit) and verified by thermal cycling and vacuum tests.

Reliability Characteristics of a Package-on-Package with Temperature/Humidity Test, Temperature Cycling Test, and High Temperature Storage Test (온도/습도 시험, 온도 싸이클링 시험 및 고온유지 시험에 따른 Package-on-Package의 신뢰성)

  • Park, Donghyun;Oh, Tae Sung
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.3
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    • pp.43-49
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    • 2016
  • Reliability characteristics of thin package-on-packages were evaluated using T/H (temperature/humidity) test at $85^{\circ}C/85%$ for 500 hours, TC (temperature cycling) test at $-40{\sim}100^{\circ}C$ for 1,000 cycles, and HTS (high temperature storage) test at $155^{\circ}C$ for 1,000 hours. The average resistance of the solder-bump circuitry between the top and bottom packages of 24 package-on-package (PoP) samples, which were processed using polyimide thermal tape, was $0.56{\pm}0.05{\Omega}$ and quite similar for all 24 samples. Open failure of solder joints did not occur after T/H test for 500 hours, TC test for 1,000 cycles, and HTS test for 1,000 hours, respectively.

Validation of sequence test method of Pb-free solder joint for automotive electronics (자동차 전장품용 무연솔더 접합부의 시리즈 시험 유효성)

  • Kim, A Young;Oh, Chul Min;Hong, Won Sik
    • Journal of Welding and Joining
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    • v.33 no.3
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    • pp.25-31
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    • 2015
  • Due to environmental regulations (RoHS, WEEE and ELV) of the European Union, electronics and automotive electronics have to eliminate toxic substance from electronic devices and system. Specifically, reliability issue of lead-free solder joint have an increasing demand for the car electronics caused by ELV banning. The authors prepared engine control unit and cabin electronics soldered with Sn-3.0Ag-0.5Cu (SAC305). To compare with the degradation characteristics of solder joint strength, thermal cycling test (TC), power-thermal cycling test (PTC) and series tests were conducted. Series tests were conducted for TC and PTC combined stress test using the same sample in sequence and continuously. TC test was performed at $-40{\sim}125^{\circ}C$ and soak time 10 min for 1000 cycles. PTC test was applied by pulse power and full function conditions during 100 cycles. Combined stress test was tested in accordance with automotive company standard. Solder joint degradation was observed by optical microscopy and environment scanning electron microscopy (ESEM). In addition, to compare with deterioration of bond strength of quad flat package (QFP) and chip components, we have measured lead pull and shear strength. Based on the series test results, consequently, we have validated of series test method for lifetime and reliability of Pb-free solder joint in automotive electronics.

An Analysis and Experimental Study for Thermal Design Verification of Satellite Electronic Equipment (인공위성 전장품의 열설계 검증을 위한 해석 및 실험적 연구)

  • Kim Jung-Hoon;Jun Hyoung Yoll;Yang Koon-Ho
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.91-95
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    • 2005
  • A heat dissipation modeling method of EEE parts is developed for thermal design and analysis of an satellite electronic equipment. The power consumption measurement value of each functional breadboard is used for the heat dissipation modeling method. For the purpose of conduction heat transfer modeling of EEE parts, surface heat model using very thin ignorable thermal plates is developed instead of conventional lumped capacity nodes. The thermal plates are projected to the printed circuit board and can be modeled and modified easily by numerically preprocessing programs according to design changes. These modeling methods are applied to the thermal design and analysis of CTU and verified by thermal cycling and vacuum tests.

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A Study on the Cyclic Oxidation Properties of Aluminum Diffusion Coated Materials (알루미늄 확산코팅재료의 주기산화 특성에 관한 연구)

  • 강석철;민경만;김길무
    • Journal of the Korean institute of surface engineering
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    • v.32 no.1
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    • pp.49-60
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    • 1999
  • The protective oxide scales and coatings formed on high temperature materials must be preserved in high temperature atmosphere. And the thermal stresses induced by thermal cycling and the growth stresses by the formation of oxide scales can cause the loss of adherence and spalling of the oxide scales and coated layers. Among the coating processes Al diffusion coating is favored due to thermochemical stability and superior adherence in an hostile atmosphere. In this study, protective oxide forming element, Al was coated on Ni, Inconel 600 and 690 by diffusion coating process varying coating temperature and time. And the surface stability and adherence of oxide scales formed on those Al diffusion coated materials were evaluated by thermal cycling test. Al diffusion coated specimens showed superior cyclic oxidation resistance compared to bare ones and specimens coated for longer period had better cyclic oxidation resistance, due to the abundant amount of Al in the coated layer. Meanwhile Al diffusion coated Inconel 600 and 690 showed improved cyclic oxidation resistance by the effect of Al in the coated layer and Cr in the substrate. Comparing both Al diffusion coated Inconel 600 and 690, Al diffusion coated Inconel 690 maintained better adhesion between coated layer and substrate by virtue of the bridging effect resulting from the segregation of Cr in the interdiffusion zone.

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The Reliability Test of Sealing Glass Frit in AC PDP

  • Jeon, Young-Hwan;Hwang, Jong-Hee;Lim, Tae-Young;Kim, Hyung-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1538-1541
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    • 2005
  • For reliability evaluation of AC-PDP, one of the most important factor is sealing property. In this paper, the reliability evaluation test method of the commercialized sealing glass frit in AC-PDP was studied. 6 inch AC-PDP panels were tested for evaluation of sealing glass frit by vibration shock test, thermal shock test, non -destructive X-ray inspection, residual stress inspection and residual gas detection. These test methods are proposed as a standard for testing the reliability of sealing glass frit. The main failure mode of sealing glass frit in AC-PDP seems to be the crack propagation from thermal cycling rather than mechanical factor.

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A SATELLITE ELECTRONIC EQUIPMENT THERMAL ANALYSIS USING SEMI-EMPERICAL HEAT DISSIPATION METHOD (반실험적 열소산 방법을 이용한 위성용 전장품 열해석)

  • Kim Jung-Hoon;Jun Hyung-Yoll;Yang Koon-Ho
    • Journal of computational fluids engineering
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    • v.11 no.2 s.33
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    • pp.32-39
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    • 2006
  • A heat dissipation modeling method of EEE parts is developed for thermal design and analysis of an satellite electronic equipment. The power consumption measurement value of each functional breadboard is used for the heat dissipation modeling method. For the purpose of conduction heat transfer modeling of EEE parts, surface heat model using very thin ignorable thermal plates is considered instead of conventional lumped capacity nodes. These modeling methods are applied to the thermal design and analysis of CTU EM and EQM and verified by thermal cycling and vacuum tests.

EFFICIENT THERMAL MODELING IN DEVELOPMENT OF A SPACEBORNE ELECTRONIC EQUIPMENT

  • Kim Jung-Hoon;Koo Ja-Chun
    • Bulletin of the Korean Space Science Society
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    • 2004.10b
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    • pp.270-273
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    • 2004
  • The initial thermal analysis needs to be fast and efficient to reduce the feedback time for the optimal electronic equipment designing. In this study, a thermal model is developed by using power consumption measurement values of each functional breadboard, that is, semi-empirical power dissipation method. In modeling heat dissipated EEE parts, power dissipation is imposed evenly on the EEE part footprint area which is projected to the printed circuit board, and is called surface heat model. The application of these methods is performed in the development of a command and telemetry unit (CTU) for a geostationary satellite. Finally, the thermal cycling test is performed to verify the applied thermal analysis methods.

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Improvement of Reliability of COG Bonding Using In, Sn Bumps and NCA (NCA 물성에 따른 극미세 피치 COG (Chip on Glass) In, Sn 접합부의 신뢰성 특성평가)

  • Chung Seung-Min;Kim Young-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.13 no.2 s.39
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    • pp.21-26
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    • 2006
  • We developed a bonding at low temperature using fine pitch Sn and In bumps, and studied the reliability of the fine pitch In-Sn solder joints. The $30{\mu}m$ pitch Sn and In bumps were joined together at $120^{\circ}C$. A non conductive adhesive (NCA) was applied during solder joining. Thermal cycling test ($0^{\circ}C-100^{\circ}C$, 2 cycles/h) of up to 2000 cycles was carried out to evaluate the reliability of the solder joints. The bondability was evaluated by measuring the contact resistance (Rc) of the joints through the four point probe method. As the content of filler increased, the reliability improved in the solder joints during thermal cycling test because the contact resistance increased little. The filler redistributed the stress and strains from the thermal shock over the entire joint area.

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