A Numerical Study of Radiator Performance under a Transient Thermal Cycle

2017 ◽  
Author(s):  
Zun Wang ◽  
Yi Zhang ◽  
Christophe lenormand ◽  
Mohammed Ansari ◽  
Manuel Henner
Keyword(s):  
Thermal Cycle ◽  
Numerical Study ◽  
Transient Thermal

Identification of thermo-mechanical fatigue fracture location by transient thermal analysis for high-temperature operating SiC power module assembled with ZnAl eutectic solder

2018 ◽  
Vol 2018 (HiTEC) ◽  
pp. 000028-000031 ◽  
Author(s):  
Fumiki Kato ◽  
Hiroki Takahashi ◽  
Hidekazu Tanisawa ◽  
Kenichi Koui ◽  
Shinji Sato ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Thermal Resistance ◽  
Thermal Cycle ◽  
Base Plate ◽  
Test Machine ◽  
Power Module ◽  
Eutectic Solder ◽  
Transient Thermal Analysis ◽  
The Individual ◽  
Transient Thermal

Abstract In this paper, we demonstrate that the structural degradation of a silicon carbide (SiC) power module corresponding to thermal cycles can be detected and tracked non-destructively by transient thermal analysis method. The purpose of this evaluation is to analyze the distribution of the thermal resistance in the power module and to identify the structure deterioration part. The power module with SiC-MOSFET were assembled using ZnAl eutectic solder as device under test. The individual thermal resistance of each part such as the SiC-die, the die-attachment, the AMCs, and the baseplate was successfully evaluated by analyzing the structure function graph. A series of thermal cycle test between −40 and 250°C was conducted, and the power modules were evaluated their thermal resistance taken out from thermal cycle test machine at 100, 200, 500 and 1000 cycles. We confirmed the increase in thermal resistance between AMCs and base plate in each thermal cycle. The portion where the thermal resistance increased is in good agreement with the location of the structural defect observed by scanning acoustic tomography (SAT) observation.

Evaluating Thermal Cycling Fatigue Resistance for LED Chip-on-Board Applications

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 000706-000737
Author(s):  
Ravi M. Bhatkal ◽  
Ranjit Pandher ◽  
Anna Lifton ◽  
Paul Koep ◽  
Hafez Raeisi Fard
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Cycle ◽  
Metal Core ◽  
Creep Fatigue ◽  
Cte Mismatch ◽  
Thermal Cycling Fatigue ◽  
Transient Thermal ◽  
The Impact

LED chip-on-board applications typically involve assembling an LED die stack directly on to a high thermal conductivity substrate such as a Metal Core PCB. If solder is used for die-substrate attach for such chip-on-board applications, one needs to consider the CTE mismatch between the die stack and the MCPCB and its impact on thermal cycle-induced creep fatigue of the solder material. This paper presents a methodology to compare relative performance of different solder materials with varying thermo-mechanical properties, and compare the impact of CTE mismatch and temperature swings on transient thermal properties and relative reliability of the solder attach materials. Implications for LED chip-on-board applications are discussed.

FE Modeling of Stress Distribution in MAO Coating on TC4 Substrate under Thermal Shock Cyclic Loading

2014 ◽  
Vol 941-944 ◽  
pp. 1629-1632 ◽  
Author(s):  
Ye Sheng Zhong ◽  
Li Ping Shi ◽  
Ming Wei Li ◽  
Jia Yu ◽  
Jian Han Liang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Adhesive Strength ◽  
Thermal Cycle ◽  
Radial Stress ◽  
Numerical Study ◽  
Element Analysis ◽  
Solid Element ◽  
Cycle Loading

A numerical study using finite element analysis (FEA) was performed to investigate the thermal, shear and radial stresses developed in MAO coating on substrate of TC4 under thermal cycle loading. The four-node quadrilateral thermal solid element PLANE55 and four-node quadrilateral structural solid element PLANE42 with axisymmetric option was used to model the temperature distribution and thermal stress field of the MAO coating on TC4 substrates. The thermal stress, radial stress and shear stress along the thickness in film/substrate system are analyzed systematically under different thermal cycle loading. It is found that the thermal stress of MAO coating exhibits a linear relationship with thickness of substrate, but it exhibit a parabolic relationship with the thickness of the coating. The radial stress and shear stress distribution of the coating–substrate combination are also calculated. It is observed that high tensile shear stress of MAO coating on TC4 substrate reduces its adhesive strength but high-compressive shear stress improves its adhesive strength.

scholarly journals Numerical Study Of Thermal Behavior Of Anisotropic Medium In Bidirectional Cylindrical Geometry

2019 ◽  
Vol 286 ◽  
pp. 08009
Author(s):  
Rabiâ Idmoussa ◽  
Nisrine Hanchi ◽  
Hamza Hamza ◽  
Jawad Lahjomri ◽  
Abdelaziz Oubarra
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Thermal Behavior ◽  
Anisotropic Medium ◽  
Numerical Study ◽  
Heat Conduction Problem ◽  
Inverse Transformation ◽  
Complicated Geometry ◽  
Alternating Directions Method ◽  
Transient Thermal

In this work, we investigate the transient thermal analysis of two-dimensional cylindrical anisotropic medium subjected to a prescribed temperature at the two end sections and to a heat flux over the whole lateral surface. Due to the complexity of analytically solving the anisotropic heat conduction equation, a numerical solution has been developed. It is based on a coordinate transformation that reduces the anisotropic cylinder heat conduction problem to an equivalent isotropic one, without complicating the boundary conditions but with a more complicated geometry. The equation of heat conduction for this virtual medium is solved by the alternating directions method. The inverse transformation makes it possible to determine the thermal behavior of the anisotropic medium as a function of study parameters: diagonal and cross thermal conductivities, heat flux.

System-Level Transient Thermal Analysis for Performance Optimization of High Power Microelectronics

2003 ◽  
Author(s):  
Victor Adrian Chiriac ◽  
Tien-Yu Tom Lee ◽  
H. S. Chen
Keyword(s):  
Thermal Performance ◽  
Performance Optimization ◽  
Numerical Study ◽  
Optimal Operation ◽  
System Level ◽  
Main Concern ◽  
Efficient Operation ◽  
Normal Test ◽  
Transient Thermal ◽  
Short Time

The increasing trend in power levels and densities leads to the need of design thermal optimization, at either module or system level. A numerical study using finite-volume software was conducted to model the transient thermal behavior of a system including a package dissipating large amounts of power over short time durations. The system is evaluated by choosing the appropriate heat sink for the efficient operation of the device under 100W of constant powering, also to enhance the thermal performance of the enclosure/box containing the test stack-up. The intent of the study is to provide a meaningful understanding and prediction of the high transient powering scenarios. The study focuses on several powering and system design scenarios, identifying the main issues encountered during a normal device operation. The power source dissipates 100W for 2 seconds then is cooled for another 2 seconds. This thermal cycle is likely to occur several times during a normal test-up, and it is the main concern of the manufacturers not to exceed a limit temperature during the device testing operation. The transient trend is further extrapolated analytically to extract the steady state peak temperature values, in order to maintain the device peak temperatures below 120°C. The benefit of the study is related to the possibility to extract the maximum/minimum temperatures for a real test involving a large number of heating-cooling cycles, yet maintaining the initial and peak temperatures within a certain range, for the optimal operation of the device. The flow and heat transfer fields are thoroughly investigated. By using a combination of numerical and analytical study, the thermal performance of the device undergoing infinity of periodic thermal cycles is further predicted.

Transient Thermal Investigation for a SmartMOS Based Airbag Circuit Driver

2002 ◽  
Author(s):  
Victor Adrian Chiriac ◽  
Tien-Yu Tom Lee ◽  
Paul Bennett
Keyword(s):  
Numerical Study ◽  
Junction Temperature ◽  
Wafer Level ◽  
Fixed Temperature ◽  
Point Temperature ◽  
Thermal Investigation ◽  
High Side ◽  
Temperature Ranges ◽  
The Right ◽  
Transient Thermal

A numerical study was conducted to model the transient thermal behavior of an airbag squib driver using commercially available software. The squib driver is part of an airbag deployment IC. The simulations were primarily used to predict the thermal gradient across the die for determining the optimal sensor location for thermal shutdown that would protect the device from destruction. The temperature sensor should be placed such that it gets hot enough for any electrical pulses that heat up the device close to the destruction point. The overall purpose is to provide a thermal detection circuit for disabling current prior to reaching a thermally destructive level. A preliminary wafer level study correlates the simulated and measured values and indicates that the junction temperature is lower for the case with thicker die and adiabatic boundary conditions; an opposite trend is observed for the cases with fixed temperature boundary condition attached to the domain bottom side. The study of the high IC side dissipating 80W for 5 ms indicates that the bottom and top center monitor points reach temperatures of 188.2°C and 130.5°C at the end of the 5 ms timeframe, corresponding to a peak source temperature of 294.6°C. A similar study with 30W uniform dissipation for 20 ms indicates that the peak junction temperature is lower than before (220°C vs. 294°C). The study of the low IC side reveals higher peak temperatures compared to the high side, due to the larger power density for these cases. The peak temperatures are 368.7°C for 50W/5 ms, and 301.8°C for 25W/20 ms. The left monitor point temperature ranges between 210°C–260°C while the right monitor point temperature ranges between 140°C–160°C. The thermal investigation of the package after the thermal shutdown predicted the time needed for the FETs to reach predetermined temperatures for different scenarios. The temperatures of the low side FETs drop by almost 50% within the 30 ms following the 20 ms of constant powering at 50W. When the high-side FETs are powered at 80W for 5 ms then cooled, the temperature rises then decays within 0.1 s.

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