The Experts below are selected from a list of 5034 Experts worldwide ranked by ideXlab platform
Fu Guo - One of the best experts on this subject based on the ideXlab platform.
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Joule Heating Effect on oxide whisker growth induced by current stressing in Cu/Sn-58Bi/Cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
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Joule Heating Effect on oxide whisker growth induced by current stressing in cu sn 58bi cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
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Effects of Joule Heating on the impact behavior of lead-free Sn-based solder joints
2010 11th International Conference on Electronic Packaging Technology & High Density Packaging, 2010Co-Authors: Sihan Liu, Fang Liu, Fu GuoAbstract:Charpy impact behaviors of eutectic SnBi solder joints with and without presence of Joule Heating Effect were investigated by employing a pendulum-type impact tester. The temperature rise induced by Joule Heating Effect at joined region can reach to 6.2 °C and 1.7 °C when the applied electric current was 10 A and 5 A, respectively. In addition, the temperature distribution of solder joints during the steady-state heat conduction was more uninform due to the sufficient mass of Cu substrates at two sides. Most important, the impact absorbed energies were the same regardless of how much of electric current was applied. The microstructure observation confirmed that the fracture mechanism was the same between the solder joints with and without presence of Joule Heating Effect. The ultimate results suggested that the weakness of solder joint was located at the interfacial layer where stress concentration possibly arose due to the interfacial reaction and the appearance of the Cu6Sn5 and Bi brittle phases.
Liqiang Cao - One of the best experts on this subject based on the ideXlab platform.
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Joule Heating Effect on oxide whisker growth induced by current stressing in Cu/Sn-58Bi/Cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
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Joule Heating Effect on oxide whisker growth induced by current stressing in cu sn 58bi cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
Chih Chen - One of the best experts on this subject based on the ideXlab platform.
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Effect of Al-Trace Width on the Electromigration Failure Time of Flip-Chip Solder Joints
Journal of Electronic Materials, 2010Co-Authors: S W Liang, Hsiang Yao Hsiao, Chih ChenAbstract:The Effect of Al-trace width on electromigration (EM) in flip-chip solder joints was investigated experimentally. EM tests were performed on eutectic Sn-Ag solders with 40-μm- and 100-μm-wide Al traces. Under the same stressing conditions (0.5 A at 165°C), the failure time was 44.1 h for solder joints with 40-μm-wide traces and 250.1 h for solder joints with 100-μm-wide traces. The Al-trace width influenced both the current crowding and the Joule Heating Effects. Thus, both Effects are responsible for the significant difference in failure time. Finite-element analysis was used to examine the current crowding Effect in solder bumps with Al traces of the two different widths. The results showed that the current crowding Effect was slightly higher in joints with 40-μm-wide traces. In addition, the temperature coefficient was used to measure the real temperatures in the solder bumps during EM. The results indicated that the width of the Al traces had a substantial influence on the Joule Heating Effect. The measured temperature in the solder bump was 218.2°C and 172.2°C for the bump with 40-μm- and 100-μm-wide Al traces, respectively. This difference in the Joule Heating Effect plays a crucial role in causing the difference in the failure time of solder joints with the two different widths.
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Investigation of Joule Heating Effect in Various Stages of Electromigration in Flip-chip Solder Joints by Infrared Microscopy
MRS Proceedings, 2010Co-Authors: Hsiang Yao Hsiao, Chih Chen, D J YaoAbstract:The Joule Heating Effect at various stages under electromigration of flip-chip Sn3.5Ag solder joints was investigated under a current of 0.5 A at 100°C. During various stages of electromigration, voids may form and propagate and Joule Heating Effect may vary at different void sizes. To verify the void nucleation and propagation on Joule Heating Effect during electromigration process, the solder bump was stressed for different lengths of time and then examined by Kelvin bump probes and infrared microscopy. We found that voids started to form at approximately 1.2 times of the initial bump resistance. Then the voids propagated when the bump resistance increased. In addition, the temperature of the solder joints increased with the bump resistance and the increase of current stressing time. It increased very slowly in initial stages. In the last stage, the temperature of the solder bump increased rapidly due to the increase of the bump resistance and the local Joule Heating Effect.
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Effect of al trace degradation on Joule Heating during electromigration in flip chip solder joints
Applied Physics Letters, 2007Co-Authors: S W Liang, S H Chiu, Chih ChenAbstract:This study investigates the mechanism for the abrupt increase in temperature at later stages of electromigration in flip-chip solder joints. It is found that electromigration also occurs in Al traces when stressed by 0.6A at 100°C. Three-dimensional thermoelectrical simulation by finite element analysis was carried out to simulate the temperature distribution in solder joints with and without degradation of the Al trace. It is found that the degradation of the Al trace has substantial Effect on the Joule Heating of solder joints. This model can explain the serious Joule Heating Effect in the later stages of electromigration.
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Three-Dimensional Thermoelectrical Simulation in Flip-Chip Solder Joints with Thick Underbump Metallizations during Accelerated Electromigration Testing
Journal of Electronic Materials, 2007Co-Authors: S W Liang, Y.w. Chang, Chih ChenAbstract:In flip-chip solder joints, thick Cu and Ni films have been used as under bump metallization (UBM) for Pb-free solders. In addition, electromigration has become a crucial reliability concern for fine-pitch flip-chip solder joints. In this paper, the three-dimensional (3-D) finite element method was employed to simulate the current-density and temperature distributions for the eutectic SnPb solder joints with 5-μm Cu, 10-μm Cu, 25-μm Cu, and 25-μm Ni UBMs. It was found that the thicker the UBM is the lower the maximum current density inside the solder. The maximum current density is 4.37 × 104 A/cm2, 1.69 × 104 A/cm2, 7.54 × 103 A/cm2, and 1.34 × 104 A/cm2, respectively, when the solder joints with the above four UBMs are stressed by 0.567 A. The solder joints with thick UBMs can Effectively relieve the current crowding Effect inside the solder. In addition, the joint with the thicker Cu UBM has a lower Joule Heating Effect in the solder. The joint with the 25-μm Ni UBM has the highest Joule Heating Effect among the four models.
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Joule Heating Effect under accelerated electromigration in flip chip solder joints
Electronic Components and Technology Conference, 2006Co-Authors: S H Chiu, S W Liang, Chih Chen, D J Yao, Y C Liu, K H Chen, S H LinAbstract:This study employs three-dimensional simulation to investigate the Joule Heating Effect under accelerated electromigration tests in flip-chip solder joints. It was found that the Joule Heating Effect was very serious during high current stressing, and a hot spot exists in the solder bump. The hot spot may play important role in the void formation and thermomigration in solder bumps during electromigration.
Lixi Wan - One of the best experts on this subject based on the ideXlab platform.
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Joule Heating Effect on oxide whisker growth induced by current stressing in Cu/Sn-58Bi/Cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
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Joule Heating Effect on oxide whisker growth induced by current stressing in cu sn 58bi cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
Haiyan Zhao - One of the best experts on this subject based on the ideXlab platform.
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Joule Heating Effect on oxide whisker growth induced by current stressing in Cu/Sn-58Bi/Cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
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Joule Heating Effect on oxide whisker growth induced by current stressing in cu sn 58bi cu solder joint
Electronic Materials Letters, 2012Co-Authors: Liqiang Cao, Lixi Wan, Haiyan Zhao, Fu GuoAbstract:The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule Heating Effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.
