The Experts below are selected from a list of 112935 Experts worldwide ranked by ideXlab platform
Ruyu Tian - One of the best experts on this subject based on the ideXlab platform.
-
brittle fracture of sn 37pb solder joints induced by enhanced intermetallic compound growth under Extreme Temperature changes
Journal of Materials Processing Technology, 2019Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong TianAbstract:Abstract A continuous layer of Ni3Sn4 compounds was formed at the Sn-37Pb solder/Ni interface in ball grid array solder joints after reflowing. Au0.5Ni0.5Sn4 compounds were formed between Sn-37Pb solder and Ni3Sn4 layer during thermal shock between -196 °C and 150 °C, and the solder/Ni interface exhibited a duplex structure of Au0.5Ni0.5Sn4 and Ni3Sn4 layers only after 300 cycles. The growth of Ni3Sn4 and Au0.5Ni0.5Sn4 under thermal shock was significantly enhanced by high thermal stresses generated from the thermal expansion mismatch between Sn-37Pb solder and Ni, and the Extreme Temperature change (ΔT = 346 °C). The fast growth and high stiffness of Ni3Sn4 and Au0.5Ni0.5Sn4, as well as the thermal expansion mismatch between Ni3Sn4 and Au0.5Ni0.5Sn4, and the Extreme Temperature change resulted in the brittle fracture of Sn-37Pb solder joints at the Ni3Sn4/Au0.5Ni0.5Sn4 interface under Extreme Temperature changes.
-
brittle fracture induced by phase transformation of ni cu sn intermetallic compounds in sn 3ag 0 5cu ni solder joints under Extreme Temperature environment
Journal of Alloys and Compounds, 2019Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong Tian, Jiayun FengAbstract:Abstract Electronic assemblies without thermal protection have to be subjected to Extreme Temperature environments during deep space exploration. In this study, Extreme Temperature thermal shock test from 77 K to 423 K was conducted to investigate the phase transformation and growth behavior of interfacial Ni-Cu-Sn intermetallic compounds (IMCs) in Sn-3Ag-0.5Cu (SAC305)/Ni solder joints, as well as their effect on solder joint reliability of Plastic Ball Grid Array (PBGA) assemblies under Extreme Temperature environment. Double layers of (Ni, Cu)3Sn2 and (Cu, Ni)6Sn5 IMCs were formed at the SAC305 solder/Ni interface after reflowing. (Cu, Ni)6Sn5 IMCs were found to gradually transform into (Ni, Cu)3Sn2 IMCs during Extreme Temperature thermal shock by transmission electron microscopy (TEM). After 300 cycles, (Cu, Ni)6Sn5 IMCs at the (Ni, Cu)3Sn2/Ni interface completely disappeared, while a new (Cu, Ni)6Sn5 IMC layer was formed on the top surface of SAC305 solder ball. The growth of interfacial Ni-Cu-Sn IMCs was significantly accelerated by the high thermal stress induced by the thermal expansion mismatch between SAC305 solder and Ni, and the large Temperature variation (ΔT = 346 K). The transformation of (Cu, Ni)6Sn5 to (Ni, Cu)3Sn2 and the fast growth of brittle (Ni, Cu)3Sn2 IMCs led to the initiation and propagation of cracks within the (Ni, Cu)3Sn2 IMC layer under high thermal stress after 300 cycles, which finally caused the brittle fracture of SAC305 PBGA solder joints after 350 cycles.
-
growth behavior of intermetallic compounds and early formation of cracks in sn 3ag 0 5cu solder joints under Extreme Temperature thermal shock
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2018Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong Tian, Liyou ZhaoAbstract:Abstract The microstructure evolution and growth mechanism of interfacial intermetallic compounds (IMCs) as well as the mechanism for early formation of cracks in Sn-3Ag-0.5Cu solder joints of quad flat packages (QFPs) during Extreme Temperature thermal shock between 77 K and 423 K were investigated. The Cu-Sn IMC layer at the Cu lead/solder interface and the Ni-Cu-Sn IMC layer at the solder/ENIG pad interface gradually thickened as well as the IMCs morphologies changed during Extreme Temperature thermal shock. Scallop-like Cu-Sn IMC layer and needle-like Ni-Cu-Sn IMC layer both transformed to plane-like IMCs. New Cu3Sn phase was formed at the interface between Cu lead and Cu6Sn5 IMC layer after 250 cycles. The (Ni, Cu)3Sn4 IMC layer was completely converted into (Cu, Ni)6Sn5 IMC layer after 150 cycles resulting from the diffusion of Cu atoms from Cu lead and Sn-3Ag-0.5Cu solder to the solder/pad interface. The time exponent (n) values of Cu-Sn and Ni-Cu-Sn IMC layers were 0.66 and 0.34, respectively, indicating that the controlling mechanisms for Cu-Sn and Ni-Cu-Sn IMC growth were bulk diffusion and grain-boundary diffusion, respectively. Cracks were formed both at the solder/Cu-Sn layer interface and at the solder/Ni-Cu-Sn layer interface after 250 cycles, due to the CTE difference between the solder and IMC, and to the thickened and flattened IMC layer. The great stress concentration resulting from the large Temperature variation (∆T = 346 K) led to the early formation of cracks. With the increase of thermal shock cycles, the pull strength of Sn-3Ag-0.5Cu solder joints decreased and the fracture location changed from within the solder to partly in Cu-Sn IMC layer and partly along the solder/Ni-Cu-Sn layer interface, which indicated that the fracture mechanism transformed from ductile fracture mode to brittle fracture mode.
Yanhong Tian - One of the best experts on this subject based on the ideXlab platform.
-
brittle fracture of sn 37pb solder joints induced by enhanced intermetallic compound growth under Extreme Temperature changes
Journal of Materials Processing Technology, 2019Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong TianAbstract:Abstract A continuous layer of Ni3Sn4 compounds was formed at the Sn-37Pb solder/Ni interface in ball grid array solder joints after reflowing. Au0.5Ni0.5Sn4 compounds were formed between Sn-37Pb solder and Ni3Sn4 layer during thermal shock between -196 °C and 150 °C, and the solder/Ni interface exhibited a duplex structure of Au0.5Ni0.5Sn4 and Ni3Sn4 layers only after 300 cycles. The growth of Ni3Sn4 and Au0.5Ni0.5Sn4 under thermal shock was significantly enhanced by high thermal stresses generated from the thermal expansion mismatch between Sn-37Pb solder and Ni, and the Extreme Temperature change (ΔT = 346 °C). The fast growth and high stiffness of Ni3Sn4 and Au0.5Ni0.5Sn4, as well as the thermal expansion mismatch between Ni3Sn4 and Au0.5Ni0.5Sn4, and the Extreme Temperature change resulted in the brittle fracture of Sn-37Pb solder joints at the Ni3Sn4/Au0.5Ni0.5Sn4 interface under Extreme Temperature changes.
-
brittle fracture induced by phase transformation of ni cu sn intermetallic compounds in sn 3ag 0 5cu ni solder joints under Extreme Temperature environment
Journal of Alloys and Compounds, 2019Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong Tian, Jiayun FengAbstract:Abstract Electronic assemblies without thermal protection have to be subjected to Extreme Temperature environments during deep space exploration. In this study, Extreme Temperature thermal shock test from 77 K to 423 K was conducted to investigate the phase transformation and growth behavior of interfacial Ni-Cu-Sn intermetallic compounds (IMCs) in Sn-3Ag-0.5Cu (SAC305)/Ni solder joints, as well as their effect on solder joint reliability of Plastic Ball Grid Array (PBGA) assemblies under Extreme Temperature environment. Double layers of (Ni, Cu)3Sn2 and (Cu, Ni)6Sn5 IMCs were formed at the SAC305 solder/Ni interface after reflowing. (Cu, Ni)6Sn5 IMCs were found to gradually transform into (Ni, Cu)3Sn2 IMCs during Extreme Temperature thermal shock by transmission electron microscopy (TEM). After 300 cycles, (Cu, Ni)6Sn5 IMCs at the (Ni, Cu)3Sn2/Ni interface completely disappeared, while a new (Cu, Ni)6Sn5 IMC layer was formed on the top surface of SAC305 solder ball. The growth of interfacial Ni-Cu-Sn IMCs was significantly accelerated by the high thermal stress induced by the thermal expansion mismatch between SAC305 solder and Ni, and the large Temperature variation (ΔT = 346 K). The transformation of (Cu, Ni)6Sn5 to (Ni, Cu)3Sn2 and the fast growth of brittle (Ni, Cu)3Sn2 IMCs led to the initiation and propagation of cracks within the (Ni, Cu)3Sn2 IMC layer under high thermal stress after 300 cycles, which finally caused the brittle fracture of SAC305 PBGA solder joints after 350 cycles.
-
growth behavior of intermetallic compounds and early formation of cracks in sn 3ag 0 5cu solder joints under Extreme Temperature thermal shock
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2018Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong Tian, Liyou ZhaoAbstract:Abstract The microstructure evolution and growth mechanism of interfacial intermetallic compounds (IMCs) as well as the mechanism for early formation of cracks in Sn-3Ag-0.5Cu solder joints of quad flat packages (QFPs) during Extreme Temperature thermal shock between 77 K and 423 K were investigated. The Cu-Sn IMC layer at the Cu lead/solder interface and the Ni-Cu-Sn IMC layer at the solder/ENIG pad interface gradually thickened as well as the IMCs morphologies changed during Extreme Temperature thermal shock. Scallop-like Cu-Sn IMC layer and needle-like Ni-Cu-Sn IMC layer both transformed to plane-like IMCs. New Cu3Sn phase was formed at the interface between Cu lead and Cu6Sn5 IMC layer after 250 cycles. The (Ni, Cu)3Sn4 IMC layer was completely converted into (Cu, Ni)6Sn5 IMC layer after 150 cycles resulting from the diffusion of Cu atoms from Cu lead and Sn-3Ag-0.5Cu solder to the solder/pad interface. The time exponent (n) values of Cu-Sn and Ni-Cu-Sn IMC layers were 0.66 and 0.34, respectively, indicating that the controlling mechanisms for Cu-Sn and Ni-Cu-Sn IMC growth were bulk diffusion and grain-boundary diffusion, respectively. Cracks were formed both at the solder/Cu-Sn layer interface and at the solder/Ni-Cu-Sn layer interface after 250 cycles, due to the CTE difference between the solder and IMC, and to the thickened and flattened IMC layer. The great stress concentration resulting from the large Temperature variation (∆T = 346 K) led to the early formation of cracks. With the increase of thermal shock cycles, the pull strength of Sn-3Ag-0.5Cu solder joints decreased and the fracture location changed from within the solder to partly in Cu-Sn IMC layer and partly along the solder/Ni-Cu-Sn layer interface, which indicated that the fracture mechanism transformed from ductile fracture mode to brittle fracture mode.
Chunjin Hang - One of the best experts on this subject based on the ideXlab platform.
-
brittle fracture of sn 37pb solder joints induced by enhanced intermetallic compound growth under Extreme Temperature changes
Journal of Materials Processing Technology, 2019Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong TianAbstract:Abstract A continuous layer of Ni3Sn4 compounds was formed at the Sn-37Pb solder/Ni interface in ball grid array solder joints after reflowing. Au0.5Ni0.5Sn4 compounds were formed between Sn-37Pb solder and Ni3Sn4 layer during thermal shock between -196 °C and 150 °C, and the solder/Ni interface exhibited a duplex structure of Au0.5Ni0.5Sn4 and Ni3Sn4 layers only after 300 cycles. The growth of Ni3Sn4 and Au0.5Ni0.5Sn4 under thermal shock was significantly enhanced by high thermal stresses generated from the thermal expansion mismatch between Sn-37Pb solder and Ni, and the Extreme Temperature change (ΔT = 346 °C). The fast growth and high stiffness of Ni3Sn4 and Au0.5Ni0.5Sn4, as well as the thermal expansion mismatch between Ni3Sn4 and Au0.5Ni0.5Sn4, and the Extreme Temperature change resulted in the brittle fracture of Sn-37Pb solder joints at the Ni3Sn4/Au0.5Ni0.5Sn4 interface under Extreme Temperature changes.
-
brittle fracture induced by phase transformation of ni cu sn intermetallic compounds in sn 3ag 0 5cu ni solder joints under Extreme Temperature environment
Journal of Alloys and Compounds, 2019Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong Tian, Jiayun FengAbstract:Abstract Electronic assemblies without thermal protection have to be subjected to Extreme Temperature environments during deep space exploration. In this study, Extreme Temperature thermal shock test from 77 K to 423 K was conducted to investigate the phase transformation and growth behavior of interfacial Ni-Cu-Sn intermetallic compounds (IMCs) in Sn-3Ag-0.5Cu (SAC305)/Ni solder joints, as well as their effect on solder joint reliability of Plastic Ball Grid Array (PBGA) assemblies under Extreme Temperature environment. Double layers of (Ni, Cu)3Sn2 and (Cu, Ni)6Sn5 IMCs were formed at the SAC305 solder/Ni interface after reflowing. (Cu, Ni)6Sn5 IMCs were found to gradually transform into (Ni, Cu)3Sn2 IMCs during Extreme Temperature thermal shock by transmission electron microscopy (TEM). After 300 cycles, (Cu, Ni)6Sn5 IMCs at the (Ni, Cu)3Sn2/Ni interface completely disappeared, while a new (Cu, Ni)6Sn5 IMC layer was formed on the top surface of SAC305 solder ball. The growth of interfacial Ni-Cu-Sn IMCs was significantly accelerated by the high thermal stress induced by the thermal expansion mismatch between SAC305 solder and Ni, and the large Temperature variation (ΔT = 346 K). The transformation of (Cu, Ni)6Sn5 to (Ni, Cu)3Sn2 and the fast growth of brittle (Ni, Cu)3Sn2 IMCs led to the initiation and propagation of cracks within the (Ni, Cu)3Sn2 IMC layer under high thermal stress after 300 cycles, which finally caused the brittle fracture of SAC305 PBGA solder joints after 350 cycles.
-
growth behavior of intermetallic compounds and early formation of cracks in sn 3ag 0 5cu solder joints under Extreme Temperature thermal shock
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2018Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong Tian, Liyou ZhaoAbstract:Abstract The microstructure evolution and growth mechanism of interfacial intermetallic compounds (IMCs) as well as the mechanism for early formation of cracks in Sn-3Ag-0.5Cu solder joints of quad flat packages (QFPs) during Extreme Temperature thermal shock between 77 K and 423 K were investigated. The Cu-Sn IMC layer at the Cu lead/solder interface and the Ni-Cu-Sn IMC layer at the solder/ENIG pad interface gradually thickened as well as the IMCs morphologies changed during Extreme Temperature thermal shock. Scallop-like Cu-Sn IMC layer and needle-like Ni-Cu-Sn IMC layer both transformed to plane-like IMCs. New Cu3Sn phase was formed at the interface between Cu lead and Cu6Sn5 IMC layer after 250 cycles. The (Ni, Cu)3Sn4 IMC layer was completely converted into (Cu, Ni)6Sn5 IMC layer after 150 cycles resulting from the diffusion of Cu atoms from Cu lead and Sn-3Ag-0.5Cu solder to the solder/pad interface. The time exponent (n) values of Cu-Sn and Ni-Cu-Sn IMC layers were 0.66 and 0.34, respectively, indicating that the controlling mechanisms for Cu-Sn and Ni-Cu-Sn IMC growth were bulk diffusion and grain-boundary diffusion, respectively. Cracks were formed both at the solder/Cu-Sn layer interface and at the solder/Ni-Cu-Sn layer interface after 250 cycles, due to the CTE difference between the solder and IMC, and to the thickened and flattened IMC layer. The great stress concentration resulting from the large Temperature variation (∆T = 346 K) led to the early formation of cracks. With the increase of thermal shock cycles, the pull strength of Sn-3Ag-0.5Cu solder joints decreased and the fracture location changed from within the solder to partly in Cu-Sn IMC layer and partly along the solder/Ni-Cu-Sn layer interface, which indicated that the fracture mechanism transformed from ductile fracture mode to brittle fracture mode.
Liyou Zhao - One of the best experts on this subject based on the ideXlab platform.
-
growth behavior of intermetallic compounds and early formation of cracks in sn 3ag 0 5cu solder joints under Extreme Temperature thermal shock
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2018Co-Authors: Ruyu Tian, Chunjin Hang, Yanhong Tian, Liyou ZhaoAbstract:Abstract The microstructure evolution and growth mechanism of interfacial intermetallic compounds (IMCs) as well as the mechanism for early formation of cracks in Sn-3Ag-0.5Cu solder joints of quad flat packages (QFPs) during Extreme Temperature thermal shock between 77 K and 423 K were investigated. The Cu-Sn IMC layer at the Cu lead/solder interface and the Ni-Cu-Sn IMC layer at the solder/ENIG pad interface gradually thickened as well as the IMCs morphologies changed during Extreme Temperature thermal shock. Scallop-like Cu-Sn IMC layer and needle-like Ni-Cu-Sn IMC layer both transformed to plane-like IMCs. New Cu3Sn phase was formed at the interface between Cu lead and Cu6Sn5 IMC layer after 250 cycles. The (Ni, Cu)3Sn4 IMC layer was completely converted into (Cu, Ni)6Sn5 IMC layer after 150 cycles resulting from the diffusion of Cu atoms from Cu lead and Sn-3Ag-0.5Cu solder to the solder/pad interface. The time exponent (n) values of Cu-Sn and Ni-Cu-Sn IMC layers were 0.66 and 0.34, respectively, indicating that the controlling mechanisms for Cu-Sn and Ni-Cu-Sn IMC growth were bulk diffusion and grain-boundary diffusion, respectively. Cracks were formed both at the solder/Cu-Sn layer interface and at the solder/Ni-Cu-Sn layer interface after 250 cycles, due to the CTE difference between the solder and IMC, and to the thickened and flattened IMC layer. The great stress concentration resulting from the large Temperature variation (∆T = 346 K) led to the early formation of cracks. With the increase of thermal shock cycles, the pull strength of Sn-3Ag-0.5Cu solder joints decreased and the fracture location changed from within the solder to partly in Cu-Sn IMC layer and partly along the solder/Ni-Cu-Sn layer interface, which indicated that the fracture mechanism transformed from ductile fracture mode to brittle fracture mode.
Sourabh Khandelwal - One of the best experts on this subject based on the ideXlab platform.
-
Extreme Temperature modeling of algan gan hemts
IEEE Transactions on Electron Devices, 2020Co-Authors: Sayed Ali Albahrani, Dhawal Mahajan, Saleh Kargarrazi, Dirk Schwantuschke, Thomas Gneiting, Debbie G. Senesky, Sourabh KhandelwalAbstract:The industry standard advanced SPICE model (ASM)-GaN compact model has been enhanced to model the GaN high electron mobility transistors (HEMTs) at Extreme Temperature conditions. In particular, the Temperature dependence of the trapping behavior has been considered and a simplifying approximation in the Temperature modeling of the saturation voltage in the ASM-GaN model has been relaxed. The enhanced model has been validated by comparing the simulation results of the model with the dc ${I}$ – ${V}$ measurement results of a GaN HEMT measured with chuck Temperatures ranging from 22 °C to 500 °C. A detailed description of the modeling approach is presented. The new formulation of the ASM-GaN compact model can be used to simulate the circuits designed for Extreme Temperature environments.
-
Extreme Temperature Modeling of AlGaN/GaN HEMTs
IEEE Transactions on Electron Devices, 2020Co-Authors: Sayed Ali Albahrani, Dhawal Mahajan, Saleh Kargarrazi, Dirk Schwantuschke, Thomas Gneiting, Debbie G. Senesky, Sourabh KhandelwalAbstract:The industry standard advanced SPICE model (ASM)-GaN compact model has been enhanced to model the GaN high electron mobility transistors (HEMTs) at Extreme Temperature conditions. In particular, the Temperature dependence of the trapping behavior has been considered and a simplifying approximation in the Temperature modeling of the saturation voltage in the ASM-GaN model has been relaxed. The enhanced model has been validated by comparing the simulation results of the model with the dc ${I}$ – ${V}$ measurement results of a GaN HEMT measured with chuck Temperatures ranging from 22 °C to 500 °C. A detailed description of the modeling approach is presented. The new formulation of the ASM-GaN compact model can be used to simulate the circuits designed for Extreme Temperature environments.
