The Experts below are selected from a list of 3813 Experts worldwide ranked by ideXlab platform
Mingxiang Chen - One of the best experts on this subject based on the ideXlab platform.
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fluid solid coupling thermo mechanical analysis of high power Led Package during thermal shock testing
Microelectronics Reliability, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Kai Wang, Mingxiang ChenAbstract:Abstract The virtual design by numerical simulation to model various accelerated reliability testing conditions is adopted to validate and improve the reliability of the high power Led Package. In this study, the reliability of the high power Led Package during thermal shock testing is investigated by fluid–solid coupling thermo-mechanical modeling by considering nonlinear time and temperature dependent material properties. Through fluid–solid coupling transient thermal transfer analysis, it is found that the maximum thermal gradient exceeds 75 K during the rapid cooling process and 91 K during the rapid heating process of the thermal shock testing which is ignored in the traditional isothermal assumption. The calculation results indicate that the equivalent plastic strain range of the bonding wire within the Led Package with consideration of the temperature gradient is much higher than that with the isothermal assumption. The assumption of the isothermal condition is not appropriate which will lead to overestimation of the predicted lifetime. The viscoelastic behaviors of the silicone have significant influences on the lifetime prediction of the bonding wire and silicone with low elastic modulus and coefficient of thermal expansion (CTE) can significantly enhance the reliability of the bonding wire under the thermal shock loading. The results in this study could provide a guideline on design for reliability in the high power Led packaging.
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study on the reliability of application specific Led Package by thermal shock testing failure analysis and fluid solid coupling thermo mechanical simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Study on the Reliability of Application-Specific Led Package by Thermal Shock Testing, Failure Analysis, and Fluid–Solid Coupling Thermo-Mechanical Simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Comparison of Led Package reliability under thermal cycling and thermal shock conditions by experimental testing and finite element simulation
2011 IEEE 61st Electronic Components and Technology Conference (ECTC), 2011Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Mingxiang ChenAbstract:High power light emitting diodes (Leds) have begun to play an important role in many illumination applications due to their excellent performance in terms of high efficiency, low power consumption, high reliability and long life. With the rapid development of the Led industry, the reliability is becoming essential for the large scale applications of Led devices, modules and systems. Generally the thermal cycling and thermal shock test are conducted for validation the reliability performance and exposure the potential design problems during the new packaging development. In this paper, the reliability performance of the typically Led Package is evaluated by the accelerated stress test under thermal cycling and thermal shock conditions. The optical degradation and electrical parameters variation of the Led Package are monitored during the experiments. The thermo-mechanical responses of the Led Package under thermal cycling and thermal shock loadings are investigated by sequential coupling thermo-mechanical finite element modeling interoperated with nonlinear time and temperature dependence materials properties. The stress and strain behavior of the Led Package especially of the gold wire is examined. The effects of thermal gradient in the Led Package during the thermal cycling and thermal shock tests and the time and temperature dependent materials property of the silicone on the reliability performance of the Led Package are investigated. The physical mechanisms of failure of Led Package samples are analyzed by decapulation and optical microscopic detection method. These efforts are helpful for design of reliability for the high power Led packaging development.
Zhaohui Chen - One of the best experts on this subject based on the ideXlab platform.
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fluid solid coupling thermo mechanical analysis of high power Led Package during thermal shock testing
Microelectronics Reliability, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Kai Wang, Mingxiang ChenAbstract:Abstract The virtual design by numerical simulation to model various accelerated reliability testing conditions is adopted to validate and improve the reliability of the high power Led Package. In this study, the reliability of the high power Led Package during thermal shock testing is investigated by fluid–solid coupling thermo-mechanical modeling by considering nonlinear time and temperature dependent material properties. Through fluid–solid coupling transient thermal transfer analysis, it is found that the maximum thermal gradient exceeds 75 K during the rapid cooling process and 91 K during the rapid heating process of the thermal shock testing which is ignored in the traditional isothermal assumption. The calculation results indicate that the equivalent plastic strain range of the bonding wire within the Led Package with consideration of the temperature gradient is much higher than that with the isothermal assumption. The assumption of the isothermal condition is not appropriate which will lead to overestimation of the predicted lifetime. The viscoelastic behaviors of the silicone have significant influences on the lifetime prediction of the bonding wire and silicone with low elastic modulus and coefficient of thermal expansion (CTE) can significantly enhance the reliability of the bonding wire under the thermal shock loading. The results in this study could provide a guideline on design for reliability in the high power Led packaging.
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study on the reliability of application specific Led Package by thermal shock testing failure analysis and fluid solid coupling thermo mechanical simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Study on the Reliability of Application-Specific Led Package by Thermal Shock Testing, Failure Analysis, and Fluid–Solid Coupling Thermo-Mechanical Simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Comparison of Led Package reliability under thermal cycling and thermal shock conditions by experimental testing and finite element simulation
2011 IEEE 61st Electronic Components and Technology Conference (ECTC), 2011Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Mingxiang ChenAbstract:High power light emitting diodes (Leds) have begun to play an important role in many illumination applications due to their excellent performance in terms of high efficiency, low power consumption, high reliability and long life. With the rapid development of the Led industry, the reliability is becoming essential for the large scale applications of Led devices, modules and systems. Generally the thermal cycling and thermal shock test are conducted for validation the reliability performance and exposure the potential design problems during the new packaging development. In this paper, the reliability performance of the typically Led Package is evaluated by the accelerated stress test under thermal cycling and thermal shock conditions. The optical degradation and electrical parameters variation of the Led Package are monitored during the experiments. The thermo-mechanical responses of the Led Package under thermal cycling and thermal shock loadings are investigated by sequential coupling thermo-mechanical finite element modeling interoperated with nonlinear time and temperature dependence materials properties. The stress and strain behavior of the Led Package especially of the gold wire is examined. The effects of thermal gradient in the Led Package during the thermal cycling and thermal shock tests and the time and temperature dependent materials property of the silicone on the reliability performance of the Led Package are investigated. The physical mechanisms of failure of Led Package samples are analyzed by decapulation and optical microscopic detection method. These efforts are helpful for design of reliability for the high power Led packaging development.
Qin Zhang - One of the best experts on this subject based on the ideXlab platform.
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fluid solid coupling thermo mechanical analysis of high power Led Package during thermal shock testing
Microelectronics Reliability, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Kai Wang, Mingxiang ChenAbstract:Abstract The virtual design by numerical simulation to model various accelerated reliability testing conditions is adopted to validate and improve the reliability of the high power Led Package. In this study, the reliability of the high power Led Package during thermal shock testing is investigated by fluid–solid coupling thermo-mechanical modeling by considering nonlinear time and temperature dependent material properties. Through fluid–solid coupling transient thermal transfer analysis, it is found that the maximum thermal gradient exceeds 75 K during the rapid cooling process and 91 K during the rapid heating process of the thermal shock testing which is ignored in the traditional isothermal assumption. The calculation results indicate that the equivalent plastic strain range of the bonding wire within the Led Package with consideration of the temperature gradient is much higher than that with the isothermal assumption. The assumption of the isothermal condition is not appropriate which will lead to overestimation of the predicted lifetime. The viscoelastic behaviors of the silicone have significant influences on the lifetime prediction of the bonding wire and silicone with low elastic modulus and coefficient of thermal expansion (CTE) can significantly enhance the reliability of the bonding wire under the thermal shock loading. The results in this study could provide a guideline on design for reliability in the high power Led packaging.
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study on the reliability of application specific Led Package by thermal shock testing failure analysis and fluid solid coupling thermo mechanical simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Study on the Reliability of Application-Specific Led Package by Thermal Shock Testing, Failure Analysis, and Fluid–Solid Coupling Thermo-Mechanical Simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Comparison of Led Package reliability under thermal cycling and thermal shock conditions by experimental testing and finite element simulation
2011 IEEE 61st Electronic Components and Technology Conference (ECTC), 2011Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Mingxiang ChenAbstract:High power light emitting diodes (Leds) have begun to play an important role in many illumination applications due to their excellent performance in terms of high efficiency, low power consumption, high reliability and long life. With the rapid development of the Led industry, the reliability is becoming essential for the large scale applications of Led devices, modules and systems. Generally the thermal cycling and thermal shock test are conducted for validation the reliability performance and exposure the potential design problems during the new packaging development. In this paper, the reliability performance of the typically Led Package is evaluated by the accelerated stress test under thermal cycling and thermal shock conditions. The optical degradation and electrical parameters variation of the Led Package are monitored during the experiments. The thermo-mechanical responses of the Led Package under thermal cycling and thermal shock loadings are investigated by sequential coupling thermo-mechanical finite element modeling interoperated with nonlinear time and temperature dependence materials properties. The stress and strain behavior of the Led Package especially of the gold wire is examined. The effects of thermal gradient in the Led Package during the thermal cycling and thermal shock tests and the time and temperature dependent materials property of the silicone on the reliability performance of the Led Package are investigated. The physical mechanisms of failure of Led Package samples are analyzed by decapulation and optical microscopic detection method. These efforts are helpful for design of reliability for the high power Led packaging development.
Seung-boo Jung - One of the best experts on this subject based on the ideXlab platform.
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Thermal Characteristic of Sn-MWCNT Nanocomposite Solder in Led Package
Proceedings - Electronic Components and Technology Conference, 2017Co-Authors: Choong-jae Lee, Jae Jung Moon, Kwang-ho Jung, Seung-boo JungAbstract:Thermal property is very important in Led lighting and junction temperature due to Led life time and luminous efficiency. An attractive approach to improve the thermal property of the solder joint is application of Multi-wall Carbon Nanotube (MWCNT) due to their outstanding mechanical, electrical and thermal property. However, MWCNTs need process of depositing metal such as Ag, Cu, Pt, Sn and Ni nanoparticle to combine MWCNT with solder. In these materials, Sn is considerable candidate because the predominant composition of lead-free solder alloys is Sn. Various approaches were employed to deposit Sn onto MWCNT. The Polyol method is a synthetic technique with simple, convenient and less energy and material consuming property. However, Sn-MWCNT nanocomposite material has difficulty to fabricate with only using polyol method due to low reduction potential of Sn. Additional process is needed to form well Sn-MWCNT nanocomposite to apply Sn based solder. We investigated Sn-MWCNT composite solder with various content of Sn-MWCNT nanocomposite to application Led Package. The MWCNT were reduced with Sn solution using polyol method to form Sn nanoparticle on surface of MWCNT. Subsequently, reducing agent solution were added under magnetic stirring. We investigated effect of additional reducing agent on MWCNT reducing process with various method. The Sn-58Bi solder pastes with various Sn-MWCNT nanocomposite contents were printed on the metal printed circuit boards (MPCBs), followed by bonding with flip-chip bonder. The temperature of Led chip with 0.1 wt.% Sn-MWCNT nanocomposite solder decreased about 3% compared to Sn-58Bi solder.
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Effects of Ag content on the reliability of Led Package component with Sn–Bi–Ag solder
Journal of Materials Science: Materials in Electronics, 2015Co-Authors: Woo Ram Myung, Min-Kwan Ko, Yongil Kim, Seung-boo JungAbstract:The effects of Ag content on the mechanical and electrical properties of the Sn–58Bi solder joints in light emitting diode (Led) Package were studied. The Sn– 58Bi, Sn–57.6Bi–0.4Ag and Sn–57Bi–1Ag solder were used as solder joints. The Led Package was bonded on the printed circuit board (PCB) with the organic solderability preservative (OSP) surface finish, and then it was aged at 85 °C for 100, 300, 500 and 1000 h, respectively. In order to evaluate the mechanical and electrical properties, the shear test was conducted and the change of current versus voltage was measured. The shear strength and electrical conductivity of solder joints decreased with an increasing aging time. With an addition of 1.0 wt% Ag, the shear strength was improved and higher than those of other solder joints. The microstructure and composition of the solder joints were investigated with a scanning electron microscope, an energy dispersive spectrometer and an electron probe micro analyzer. The Cu 6 Sn 5 intermetallic compounds (IMCs) formed between solder and OSP sur-face finished Cu pad of PCB. The thickness of the IMCs increased with an increasing aging time. By an addition of 0.4 wt% Ag, fine Ag 3 Sn particles were dispersed inside the solder matrix and large-sized primary Ag 3 Sn IMCs were formed with 1.0 wt% Ag addition.
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Fabrication of Ag-MWNT nanocomposite paste for high-power Led Package
Current Applied Physics, 2015Co-Authors: Kwang Seok Kim, Hyo Soo Lee, Bum Geun Park, Hongsik Kim, Seung-boo JungAbstract:Abstract A silver-multi-walLed carbon nanotube (Ag-MWNT) nanocomposite was utilized as a thermal interface material for a high-power light-emitting diode (Led) Package. The nanocomposite was fabricated by screen printing and sintering of a nanocomposite paste comprising Ag-decorated MWNTs mixed with Ag nanoparticles dispersed in an organic solvent. The Ag-MWNT nanocomposite sintered at 300°C for 30 min with 3 wt.% MWNT exhibited the highest thermal conductivity of 21.1 W/mK at room temperature and the lowest thermal resistance of ∼6.6 K/W. Percolation networks of Ag-decorated MWNTs between Ag nanoparticles Led to improved thermal conduction, resulting in excellent heat dissipation and luminous efficiency of the high-power Led Package. The Led Package fabricated with an Ag nanocomposite paste containing 3 wt.% MWNT exhibited a 7% decrease in operating temperature of Led chips compared with that of the basic structure of a metal printed circuit board.
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Effect of Multiple Reflows on the Mechanical Reliability of Solder Joint in Led Package
Korean Journal of Metals and Materials, 2010Co-Authors: Jeong-won Yoon, Min-Kwan Ko, Seung-boo JungAbstract:The research efforts on GaN-based light-emitting diodes (Leds) keep increasing due to their significant impact on the illumination industry. Surface mount technology (SMT) is widely used to mount the Led Packages for practical application. In surface mount soldering both the device body and leads are intentionally heated by a reflow process. We studied on the effects of multiple reflows on microstructural variation and joint strength of the solder joints between the Led Package and the substrate. In this study, Pb-free Sn-3.0Ag-0.5Cu solder and a finished pad with organic solderability preservatives (OSP) were employed. A Cu6Sn5 intermetallic compound (IMC) layer was formed during the multiple reflows, and the thickness of the IMC layerincreased with an increasing number of reflows. The shear force decreased after three reflows. From the observation of the fracture surface after a shear test, partially brittle fractures were observed after five reflows. (Received May 20, 2010)
Feng Jiao - One of the best experts on this subject based on the ideXlab platform.
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study on the reliability of application specific Led Package by thermal shock testing failure analysis and fluid solid coupling thermo mechanical simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Study on the Reliability of Application-Specific Led Package by Thermal Shock Testing, Failure Analysis, and Fluid–Solid Coupling Thermo-Mechanical Simulation
IEEE Transactions on Components Packaging and Manufacturing Technology, 2012Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Kai Wang, Mingxiang ChenAbstract:Reliability is essential for large-scale applications of high-power light-emitting diode (Led) devices, modules, and systems for general illumination. In this paper, the reliability of a novel application-specific Led Package (ASLP) is investigated by thermal shock testing, failure analysis, and fluid-solid coupling thermo-mechanical simulation. The reliability of the ASLP modules was validated with a dual-bath liquid thermal shock testing from 233 to 398 K. The non-destructive failure analysis was conducted to the catastrophic failure ASLP samples by fluorescent penetrant inspection. The delaminations at the interfaces within the ASLP module were detected. The failure mechanisms were identified by digital optical microscopy and field emission scanning electron microscope inspection after the decapsulation. The experimental results show that fracture failure occurs at the wedge joint of the bonding wire, which leads to the catastrophic failure of the ASLP module. The stress and strain behaviors of the ASLP module, especially the bonding wire under thermal shock loading, were analyzed through thermo-mechanical modeling with the nonlinear time- and temperature-dependent material properties. Significant thermal gradient within the ASLP module during the thermal shock testing was taken into consideration by the fluid-solid coupling transient thermal transfer analysis. The effects of the delaminations detected by the fluorescent penetrant inspection on the reliability of the bonding wire were also examined. It is found the delaminations existing at the interfaces within the ASLP module induce significant plastic strain to the wedge joint and results in fracture failure. The results from the numerical simulation can make a good prediction of the failure mechanism of the ASLP modules under thermal shock loading.
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Comparison of Led Package reliability under thermal cycling and thermal shock conditions by experimental testing and finite element simulation
2011 IEEE 61st Electronic Components and Technology Conference (ECTC), 2011Co-Authors: Zhaohui Chen, Qin Zhang, Run Chen, Feng Jiao, Mingxiang ChenAbstract:High power light emitting diodes (Leds) have begun to play an important role in many illumination applications due to their excellent performance in terms of high efficiency, low power consumption, high reliability and long life. With the rapid development of the Led industry, the reliability is becoming essential for the large scale applications of Led devices, modules and systems. Generally the thermal cycling and thermal shock test are conducted for validation the reliability performance and exposure the potential design problems during the new packaging development. In this paper, the reliability performance of the typically Led Package is evaluated by the accelerated stress test under thermal cycling and thermal shock conditions. The optical degradation and electrical parameters variation of the Led Package are monitored during the experiments. The thermo-mechanical responses of the Led Package under thermal cycling and thermal shock loadings are investigated by sequential coupling thermo-mechanical finite element modeling interoperated with nonlinear time and temperature dependence materials properties. The stress and strain behavior of the Led Package especially of the gold wire is examined. The effects of thermal gradient in the Led Package during the thermal cycling and thermal shock tests and the time and temperature dependent materials property of the silicone on the reliability performance of the Led Package are investigated. The physical mechanisms of failure of Led Package samples are analyzed by decapulation and optical microscopic detection method. These efforts are helpful for design of reliability for the high power Led packaging development.