Pub Date : 2021-12-02DOI: 10.1108/ssmt-08-2021-0058
Guangsen Chen, Yaofeng Wu
Purpose The purpose of this paper is to investigate the effect of titanium nitride (TiN) on microstructure and composition of 96.5Sn3Ag0.5Cu (SAC305) lead-free solder joints under a large temperature gradient. Design/methodology/approach In this paper, SAC305 lead-free composite solder containing 0.05 Wt.% TiN was prepared by powder metallurgy method. A temperature gradient generator was designed and the corresponding samples were also prepared. The microstructural evolution, internal structure and elemental content of SAC305 and SAC305/TiN solder joints before and after thermal loading were comparatively studied. Findings The experimental results show that the addition of the TiN reinforcing phase can effectively inhibit the diffusion and migration of copper atoms and, therefore, affect the distribution of newly formed Cu-Sn IMC in solder joints under the condition of thermal migration (TM). Compared with the SAC305 solder joint, the interconnection interface and internal structure of the composite solder joint after 600 h of TM are also relatively complete. Originality/value The TiN reinforcing phase is proven effective to mitigate the TM behavior in solder joints under thermal stressing. Specifically, based on the observation and analysis results of microstructure and internal structure of composite solder joint, the TiN particle can change the temperature gradient distribution of the solder joint, so as to suppress the diffusion and migration of Sn and Cu atoms. In addition, the results of Micro-CT and compositional analysis also indicate that the addition of TiN reinforcement is very helpful to maintain the structural integrity and the compositional stability of the solder joint. Different from other ceramic reinforcements, TiN has good thermo- and electro-conductivity and the thermal-electrical performance of composite solder will not be significantly affected by this reinforcement, which is also the main advantage of selecting TiN as the reinforcing phase to prepare composite solder. This study can not only provide preliminary experimental support for the preparation of high reliability lead-free composite solder but also provide a theoretical basis for the subsequent study (such as electro-thermo distribution in solder joints), which has important application significance.
{"title":"Microstructural and compositional evolution of SAC305/TiN composite solder under thermal stressing","authors":"Guangsen Chen, Yaofeng Wu","doi":"10.1108/ssmt-08-2021-0058","DOIUrl":"https://doi.org/10.1108/ssmt-08-2021-0058","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to investigate the effect of titanium nitride (TiN) on microstructure and composition of 96.5Sn3Ag0.5Cu (SAC305) lead-free solder joints under a large temperature gradient.\u0000\u0000\u0000Design/methodology/approach\u0000In this paper, SAC305 lead-free composite solder containing 0.05 Wt.% TiN was prepared by powder metallurgy method. A temperature gradient generator was designed and the corresponding samples were also prepared. The microstructural evolution, internal structure and elemental content of SAC305 and SAC305/TiN solder joints before and after thermal loading were comparatively studied.\u0000\u0000\u0000Findings\u0000The experimental results show that the addition of the TiN reinforcing phase can effectively inhibit the diffusion and migration of copper atoms and, therefore, affect the distribution of newly formed Cu-Sn IMC in solder joints under the condition of thermal migration (TM). Compared with the SAC305 solder joint, the interconnection interface and internal structure of the composite solder joint after 600 h of TM are also relatively complete.\u0000\u0000\u0000Originality/value\u0000The TiN reinforcing phase is proven effective to mitigate the TM behavior in solder joints under thermal stressing. Specifically, based on the observation and analysis results of microstructure and internal structure of composite solder joint, the TiN particle can change the temperature gradient distribution of the solder joint, so as to suppress the diffusion and migration of Sn and Cu atoms. In addition, the results of Micro-CT and compositional analysis also indicate that the addition of TiN reinforcement is very helpful to maintain the structural integrity and the compositional stability of the solder joint. Different from other ceramic reinforcements, TiN has good thermo- and electro-conductivity and the thermal-electrical performance of composite solder will not be significantly affected by this reinforcement, which is also the main advantage of selecting TiN as the reinforcing phase to prepare composite solder. This study can not only provide preliminary experimental support for the preparation of high reliability lead-free composite solder but also provide a theoretical basis for the subsequent study (such as electro-thermo distribution in solder joints), which has important application significance.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47168459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-09DOI: 10.1108/ssmt-09-2021-0062
Xinmeng Zhai, Yue Chen, Yue-Rong Li
Purpose The purpose of this paper is to develop a new composite solder to improve the reliability of composite solder joints. Nano-particles modified multi-walled carbon nanotubes (Ni-MWCNTs) can indeed improve the microstructure of composite solder joints and improve the reliability of solder joints. Although many people have conducted in-depth research on the composite solder of Ni-MWCNTs. However, no one has studied the performance of Ni-MWCNTs composite solder under different aging conditions. In this article, Ni-MWCNTs was added to Sn-Ag-Cu (SAC) solder, and the physical properties of composite solder, the microstructure and mechanical properties were evaluated. Design/methodology/approach In this study, the effect of different aging conditions on the intermetallic compound (IMC) layer growth and shear strength of Ni-modified MWCNTs reinforced SAC composite solder was studied. Compared with SAC307 solder alloy, the influence of Ni-MWCNTs with different contents (0, 0.1 and 0.2 Wt.%) on composite solder was examined. To study the aging characteristics of composite solder joints, the solder joints were aged at 80°C, 120°C and 150°C. Findings The experimental results show that the content of Ni-MWCNTs affects the morphology and growth of the IMC layer at the interface. The microhardness of the solder increases and the wetting angle decreases. After aging at moderate (120°C) and high temperature (150°C), the morphology of the Cu6Sn5 IMC layer changed from scallop to lamellar and the grain size became coarser. The following two different phase compositions were observed in the solder joints with Ni-MWCNTs reinforcement: Cu3Sn and (Cu, Ni)6Sn5. The fracture surface of the solder joints all appeared ductile dents, and the size of the pits increased significantly with the increase of the aging temperature. Through growth kinetic analysis, Ni-modified MWCNTs in composite solder joints can effectively inhibit the diffusion of atoms in solder joints. In short, when the addition amount of Ni-MWCNTs is 0.1 Wt.%, the solder joints exhibit the best wettability and the highest shear strength. Originality/value In this study, the effects of aging conditions on the growth and shear strength of the IMC layer of Ni modified MWCNTs reinforced SAC307 composite solder were studied. The effects of Ni MWCNTs with different contents (0, 0.1 and 0.2 Wt.%) on the composite solder were examined.
{"title":"Impact of different aging conditions on the IMC layer growth and shear strength of Ni-modified MWCNTs reinforced Sn-Ag-Cu composite solder","authors":"Xinmeng Zhai, Yue Chen, Yue-Rong Li","doi":"10.1108/ssmt-09-2021-0062","DOIUrl":"https://doi.org/10.1108/ssmt-09-2021-0062","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to develop a new composite solder to improve the reliability of composite solder joints. Nano-particles modified multi-walled carbon nanotubes (Ni-MWCNTs) can indeed improve the microstructure of composite solder joints and improve the reliability of solder joints. Although many people have conducted in-depth research on the composite solder of Ni-MWCNTs. However, no one has studied the performance of Ni-MWCNTs composite solder under different aging conditions. In this article, Ni-MWCNTs was added to Sn-Ag-Cu (SAC) solder, and the physical properties of composite solder, the microstructure and mechanical properties were evaluated.\u0000\u0000\u0000Design/methodology/approach\u0000In this study, the effect of different aging conditions on the intermetallic compound (IMC) layer growth and shear strength of Ni-modified MWCNTs reinforced SAC composite solder was studied. Compared with SAC307 solder alloy, the influence of Ni-MWCNTs with different contents (0, 0.1 and 0.2 Wt.%) on composite solder was examined. To study the aging characteristics of composite solder joints, the solder joints were aged at 80°C, 120°C and 150°C.\u0000\u0000\u0000Findings\u0000The experimental results show that the content of Ni-MWCNTs affects the morphology and growth of the IMC layer at the interface. The microhardness of the solder increases and the wetting angle decreases. After aging at moderate (120°C) and high temperature (150°C), the morphology of the Cu6Sn5 IMC layer changed from scallop to lamellar and the grain size became coarser. The following two different phase compositions were observed in the solder joints with Ni-MWCNTs reinforcement: Cu3Sn and (Cu, Ni)6Sn5. The fracture surface of the solder joints all appeared ductile dents, and the size of the pits increased significantly with the increase of the aging temperature. Through growth kinetic analysis, Ni-modified MWCNTs in composite solder joints can effectively inhibit the diffusion of atoms in solder joints. In short, when the addition amount of Ni-MWCNTs is 0.1 Wt.%, the solder joints exhibit the best wettability and the highest shear strength.\u0000\u0000\u0000Originality/value\u0000In this study, the effects of aging conditions on the growth and shear strength of the IMC layer of Ni modified MWCNTs reinforced SAC307 composite solder were studied. The effects of Ni MWCNTs with different contents (0, 0.1 and 0.2 Wt.%) on the composite solder were examined.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42049676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-01DOI: 10.1108/ssmt-08-2021-0052
Yang Liu, Yuxiong Xue, Min Zhou, Rongxing Cao, Xiaoliang Zeng, Hongxia Li, S. Zheng, Shuang Zhang
Purpose The purpose of this paper is to investigate the effects of Sn-Ag-x leveling layers on the mechanical properties of SnBi solder joints. Four Sn-Ag-x (Sn-3.0Ag-0.5Cu, Sn-0.3Ag-0.7Cu, Sn-0.3Ag-0.7Cu-0.5 Bi-0.05Ni and Sn-3.0Ag-3.0 Bi-3.0In) leveling layers were coated on Cu pads to prepare SnBi/Sn-Ag-x/Cu solder joints. The microstructure, hardness, shear strength and fracture morphology of solder joints before and after aging were studied. Design/methodology/approach The interfacial brittleness of the SnBi low-temperature solder joint is a key problem affecting its reliability. The purpose of this study is to improve the mechanical properties of the SnBi solder joint. Findings Owing to the addition of the leveling layers, the grain size of the ß-Sn phase in the SnBi/Sn-Ag-x/Cu solder joint is significantly larger than that in the SnBi/Cu eutectic solder joint. Meanwhile, the hardness of the solder bulk in the SnBi/Cu solder joint shows a decrease trend because of the addition of the leveling layers. The SnBi/Cu solder joint shows obvious strength drop and interfacial brittle fracture after aging. Through the addition of the Sn-Ag-x layers, the brittle failure caused by aging is effectively suppressed. In addition, the Sn-Ag-x leveling layers improve the shear strength of the SnBi/Cu solder joint after aging. Among them, the SnBi/SACBN/Cu solder joint shows the highest shear strength. Originality/value This work suppresses the interfacial brittleness of the SnBi/Cu solder joint after isothermal aging by adding Sn-Ag-x leveling layers on the Cu pads. It provides a way to improve the mechanical performances of the SnBi solder joint.
{"title":"Effects of Sn-Ag-x leveling layers on the microstructure and mechanical properties of SnBi low-temperature solder joints","authors":"Yang Liu, Yuxiong Xue, Min Zhou, Rongxing Cao, Xiaoliang Zeng, Hongxia Li, S. Zheng, Shuang Zhang","doi":"10.1108/ssmt-08-2021-0052","DOIUrl":"https://doi.org/10.1108/ssmt-08-2021-0052","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to investigate the effects of Sn-Ag-x leveling layers on the mechanical properties of SnBi solder joints. Four Sn-Ag-x (Sn-3.0Ag-0.5Cu, Sn-0.3Ag-0.7Cu, Sn-0.3Ag-0.7Cu-0.5 Bi-0.05Ni and Sn-3.0Ag-3.0 Bi-3.0In) leveling layers were coated on Cu pads to prepare SnBi/Sn-Ag-x/Cu solder joints. The microstructure, hardness, shear strength and fracture morphology of solder joints before and after aging were studied.\u0000\u0000\u0000Design/methodology/approach\u0000The interfacial brittleness of the SnBi low-temperature solder joint is a key problem affecting its reliability. The purpose of this study is to improve the mechanical properties of the SnBi solder joint.\u0000\u0000\u0000Findings\u0000Owing to the addition of the leveling layers, the grain size of the ß-Sn phase in the SnBi/Sn-Ag-x/Cu solder joint is significantly larger than that in the SnBi/Cu eutectic solder joint. Meanwhile, the hardness of the solder bulk in the SnBi/Cu solder joint shows a decrease trend because of the addition of the leveling layers. The SnBi/Cu solder joint shows obvious strength drop and interfacial brittle fracture after aging. Through the addition of the Sn-Ag-x layers, the brittle failure caused by aging is effectively suppressed. In addition, the Sn-Ag-x leveling layers improve the shear strength of the SnBi/Cu solder joint after aging. Among them, the SnBi/SACBN/Cu solder joint shows the highest shear strength.\u0000\u0000\u0000Originality/value\u0000This work suppresses the interfacial brittleness of the SnBi/Cu solder joint after isothermal aging by adding Sn-Ag-x leveling layers on the Cu pads. It provides a way to improve the mechanical performances of the SnBi solder joint.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44520767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose The purpose of this study is to investigate the effect of electrical and thermal stresses on the void formation of the Sn3.0Ag0.5Cu (SAC305) lead-free ball grid array (BGA) solder joints and to propose a modified mean-time-to-failure (MTTF) equation when joints are subjected to coupling stress. Design/methodology/approach The samples of the BGA package were subjected to a migration test at different currents and temperatures. Voltage variation was recorded for analysis. Scanning electron microscope and electron back-scattered diffraction were applied to achieve the micromorphological observations. Additionally, the experimental and simulation results were combined to fit the modified model parameters. Findings Voids appeared at the corner of the cathode. The resistance of the daisy chain increased. Two stages of resistance variation were confirmed. The crystal lattice orientation rotated and became consistent and ordered. Electrical and thermal stresses had an impact on the void formation. As the current density and temperature increased, the void increased. The lifetime of the solder joint decreased as the electrical and thermal stresses increased. A modified MTTF model was proposed and its parameters were confirmed by theoretical derivation and test data fitting. Originality/value This study focuses on the effects of coupling stress on the void formation of the SAC305 BGA solder joint. The microstructure and macroscopic performance were studied to identify the effects of different stresses with the use of a variety of analytical methods. The modified MTTF model was constructed for application to SAC305 BGA solder joints. It was found suitable for larger current densities and larger influences of Joule heating and for the welding ball structure with current crowding.
{"title":"A study on the effects of electrical and thermal stresses on void formation and migration lifetime of Sn3.0Ag0.5Cu solder joints","authors":"Yanruoyue Li, Guicui Fu, B. Wan, Zhaoxi Wu, Xiaojun Yan, Weifang Zhang","doi":"10.1108/ssmt-04-2021-0012","DOIUrl":"https://doi.org/10.1108/ssmt-04-2021-0012","url":null,"abstract":"\u0000Purpose\u0000The purpose of this study is to investigate the effect of electrical and thermal stresses on the void formation of the Sn3.0Ag0.5Cu (SAC305) lead-free ball grid array (BGA) solder joints and to propose a modified mean-time-to-failure (MTTF) equation when joints are subjected to coupling stress.\u0000\u0000\u0000Design/methodology/approach\u0000The samples of the BGA package were subjected to a migration test at different currents and temperatures. Voltage variation was recorded for analysis. Scanning electron microscope and electron back-scattered diffraction were applied to achieve the micromorphological observations. Additionally, the experimental and simulation results were combined to fit the modified model parameters.\u0000\u0000\u0000Findings\u0000Voids appeared at the corner of the cathode. The resistance of the daisy chain increased. Two stages of resistance variation were confirmed. The crystal lattice orientation rotated and became consistent and ordered. Electrical and thermal stresses had an impact on the void formation. As the current density and temperature increased, the void increased. The lifetime of the solder joint decreased as the electrical and thermal stresses increased. A modified MTTF model was proposed and its parameters were confirmed by theoretical derivation and test data fitting.\u0000\u0000\u0000Originality/value\u0000This study focuses on the effects of coupling stress on the void formation of the SAC305 BGA solder joint. The microstructure and macroscopic performance were studied to identify the effects of different stresses with the use of a variety of analytical methods. The modified MTTF model was constructed for application to SAC305 BGA solder joints. It was found suitable for larger current densities and larger influences of Joule heating and for the welding ball structure with current crowding.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44013731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-14DOI: 10.1108/ssmt-06-2021-0037
Chien-Yi Huang, Christopher Greene, Chao-Chieh Chan, Pingshan Wang
Purpose This study aims to focus on the passive components of System in Package SiP modules and discusses the geometric pad designs for 01005-sized passive components, the front end design of the hole size and shape of the stencil and the parameters of the stencil sidewall coating, to determine the optimum parameter combination. Design/methodology/approach This study plans and conducts experiments, where a L8(27) inner orthogonal array is built to consider the control factors, including a L4(23) outer orthogonal array to consider the noise factor, and the experimental data are analyzed by using the technique for order preference by similarity to ideal solution multi-quality analysis method. Findings The results show that the optimum design parameter level combination is that the solder mask opening pad has no solder mask in the lower part of the component, the pad width is 1.1 times that of the component width, the pad length is 1.75 times that of the electrode tip length, the pad spacing is 5 mil, the stencil open area is 90% of the pad area, the stencil opening corner has a 3 mil chamfer angle, and the stencil sidewall is free of nano-coating. Originality/value The parameter design and multi-quality analysis method, as proposed in this study, can effectively develop the layout of passive components on a high-density SiP module substrate, to stabilize the process and increase the production yield.
本研究以System in Package SiP模块的无源器件为研究对象，对01005尺寸无源器件的几何衬垫设计、前端模板孔尺寸和形状的设计以及模板侧壁涂层的参数进行了探讨，确定了最优的参数组合。设计/方法学/方法本研究计划并进行实验，构建L8(27)内正交阵列考虑控制因素，构建L4(23)外正交阵列考虑噪声因素，采用与理想解多质量分析法相似度排序偏好技术对实验数据进行分析。FindingsThe结果表明,优化设计参数水平组合焊接掩模口垫没有焊接掩模的下部组件,组件的垫宽度是1.1倍,宽度,垫的长度是1.75倍的电极头长度、板间距5毫升,打开模板面积板面积的90%,模板打开角落里有3 mil倒角和nano-coating模板侧壁是免费的。本研究提出的参数设计和多质量分析方法，可以有效地开发高密度SiP模块基板上无源元件的布局，稳定工艺，提高产量。
{"title":"Design criteria for pad and stencil with high pick-and-Place yield","authors":"Chien-Yi Huang, Christopher Greene, Chao-Chieh Chan, Pingshan Wang","doi":"10.1108/ssmt-06-2021-0037","DOIUrl":"https://doi.org/10.1108/ssmt-06-2021-0037","url":null,"abstract":"\u0000Purpose\u0000This study aims to focus on the passive components of System in Package SiP modules and discusses the geometric pad designs for 01005-sized passive components, the front end design of the hole size and shape of the stencil and the parameters of the stencil sidewall coating, to determine the optimum parameter combination.\u0000\u0000\u0000Design/methodology/approach\u0000This study plans and conducts experiments, where a L8(27) inner orthogonal array is built to consider the control factors, including a L4(23) outer orthogonal array to consider the noise factor, and the experimental data are analyzed by using the technique for order preference by similarity to ideal solution multi-quality analysis method.\u0000\u0000\u0000Findings\u0000The results show that the optimum design parameter level combination is that the solder mask opening pad has no solder mask in the lower part of the component, the pad width is 1.1 times that of the component width, the pad length is 1.75 times that of the electrode tip length, the pad spacing is 5 mil, the stencil open area is 90% of the pad area, the stencil opening corner has a 3 mil chamfer angle, and the stencil sidewall is free of nano-coating.\u0000\u0000\u0000Originality/value\u0000The parameter design and multi-quality analysis method, as proposed in this study, can effectively develop the layout of passive components on a high-density SiP module substrate, to stabilize the process and increase the production yield.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42193807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-04DOI: 10.1108/ssmt-07-2021-0047
Zhenya Pan, F. Sun
Purpose The purpose of this paper is to design a novel die-attach composite joint for high-temperature die-attach applications based on transient liquid phase bonding. Moreover, the microstructure, shear strength, electrical property, thermal conductivity and aging property of the composite joint were investigated. Design/methodology/approach The composite joint was made of microporous copper and Cu3Sn. Microporous copper was immersed into liquid Sn to achieve Sn-microporous copper composite structure for die attachment. By the thermo-compression bonding, the Cu3Sn-microporous copper composite joint with a thickness of 100 µm was successfully obtained after bonding at 350 °C for 5 min under a low pressure of 0.6 MPa. Findings After thermo-compression bonding, the resulting interconnection could withstand a high temperature of at most 676 °C, with the entire Sn transforming into Cu3Sn with high remelting temperatures. A large shear strength could be achieved with the Cu3Sn-microporous copper in the interconnections. The formed bondlines demonstrated a good electrical and thermal conductivity owing to the large existing amount of copper in the interconnections. Furthermore, the interconnection also exhibited excellent reliability under high temperature aging at 300 °C. Originality/value This die-attach composite joint was suitable for power devices operating under high temperatures or other harsh environments.
{"title":"Cu3Sn-microporous copper composite joint for high-temperature die-attach applications","authors":"Zhenya Pan, F. Sun","doi":"10.1108/ssmt-07-2021-0047","DOIUrl":"https://doi.org/10.1108/ssmt-07-2021-0047","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to design a novel die-attach composite joint for high-temperature die-attach applications based on transient liquid phase bonding. Moreover, the microstructure, shear strength, electrical property, thermal conductivity and aging property of the composite joint were investigated.\u0000\u0000\u0000Design/methodology/approach\u0000The composite joint was made of microporous copper and Cu3Sn. Microporous copper was immersed into liquid Sn to achieve Sn-microporous copper composite structure for die attachment. By the thermo-compression bonding, the Cu3Sn-microporous copper composite joint with a thickness of 100 µm was successfully obtained after bonding at 350 °C for 5 min under a low pressure of 0.6 MPa.\u0000\u0000\u0000Findings\u0000After thermo-compression bonding, the resulting interconnection could withstand a high temperature of at most 676 °C, with the entire Sn transforming into Cu3Sn with high remelting temperatures. A large shear strength could be achieved with the Cu3Sn-microporous copper in the interconnections. The formed bondlines demonstrated a good electrical and thermal conductivity owing to the large existing amount of copper in the interconnections. Furthermore, the interconnection also exhibited excellent reliability under high temperature aging at 300 °C.\u0000\u0000\u0000Originality/value\u0000This die-attach composite joint was suitable for power devices operating under high temperatures or other harsh environments.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43367811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose The purpose of this article is the effect of doping minor Ni on the microstructure evolution of a Sn-xNi (x = 0, 0.05 and 0.1 wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment. Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of interfacial layer was different due to the different mechanism of element diffusion of the two substrates. The PC Ni substrate mainly provided Ni atoms through grain boundary diffusion. The Ni3Sn4 phase of the Sn0.05Ni/PC Ni joint was finer, and the diffusion flux of Sn and Ni elements increased, so the Ni3Sn4 layer of this joint was the thickest. The SC Ni substrate mainly provided Ni atoms through the lattice diffusion. The Sn0.1Ni/SC Ni joint increases the number of Ni atoms at the interface due to the doping of 0.1Ni (wt.%) elements, so the joint had the thickest NiSn4 layer. Design/methodology/approach The effects of doping minor Ni on the microstructure evolution of an Sn-xNi (x = 0, 0.05 and 0.1 Wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment was investigated in this study. Findings Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of the interfacial layer was different due to the different mechanisms of element diffusion of the two substrates. Originality/value In this study, the effect of doping Ni on the growth and formation mechanism of IMCs of the Sn-xNi/Ni (single-crystal) solder joints (x = 0, 0.05 and 0.1 Wt.%) was investigated.
{"title":"Effects of doping trace Ni element on interfacial behavior of Sn/Ni (polycrystal/single-crystal) joints","authors":"Jianing Wang, Jieshi Chen, Zhiyuan Zhang, Pei-lei Zhang, Zhishui Yu, Shuye Zhang","doi":"10.1108/ssmt-08-2021-0053","DOIUrl":"https://doi.org/10.1108/ssmt-08-2021-0053","url":null,"abstract":"\u0000Purpose\u0000The purpose of this article is the effect of doping minor Ni on the microstructure evolution of a Sn-xNi (x = 0, 0.05 and 0.1 wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment. Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of interfacial layer was different due to the different mechanism of element diffusion of the two substrates. The PC Ni substrate mainly provided Ni atoms through grain boundary diffusion. The Ni3Sn4 phase of the Sn0.05Ni/PC Ni joint was finer, and the diffusion flux of Sn and Ni elements increased, so the Ni3Sn4 layer of this joint was the thickest. The SC Ni substrate mainly provided Ni atoms through the lattice diffusion. The Sn0.1Ni/SC Ni joint increases the number of Ni atoms at the interface due to the doping of 0.1Ni (wt.%) elements, so the joint had the thickest NiSn4 layer.\u0000\u0000\u0000Design/methodology/approach\u0000The effects of doping minor Ni on the microstructure evolution of an Sn-xNi (x = 0, 0.05 and 0.1 Wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment was investigated in this study.\u0000\u0000\u0000Findings\u0000Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of the interfacial layer was different due to the different mechanisms of element diffusion of the two substrates.\u0000\u0000\u0000Originality/value\u0000In this study, the effect of doping Ni on the growth and formation mechanism of IMCs of the Sn-xNi/Ni (single-crystal) solder joints (x = 0, 0.05 and 0.1 Wt.%) was investigated.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45301994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-16DOI: 10.1108/ssmt-07-2021-0049
Jianhua Wang, Hongbo Xu, Li Zhou, Ximing Liu, Hongyun Zhao
Purpose This paper aims to investigate the mechanism of Ni particles distribution in the liquid Sn3.5Ag melt under the external static magnetic field. The control steps of Ni particles and the Sn3.5Ag melt metallurgical process were studied. After aging, the microhardness of pure Sn3.5Ag, Sn3.5Ag containing randomly distributed Ni particles and Sn3.5Ag containing columnar Ni particles were compared. Design/methodology/approach Place the sample in a crucible for heating. After the sample melts, place a magnet directly above and below the sample to provide a magnetic field. Sn3.5Ag with the different morphological distribution of Ni particles was obtained by holding for different times under different magnetic field intensities. Finally, pure Sn3.5Ag, Sn3.5Ag with random distributed Ni particles and Sn3.5Ag with columnar Ni particles were aged and their microhardness was tested after aging. Findings The experimental results show that with the increase of magnetic field strength, the time for Ni particle distribution in Sn3.5Ag melt to reach equilibrium is shortened. After aging, the microhardness of Sn3.5Ag containing columnar nickel particles is higher than that of pure Sn3.5Ag and Sn3.5Ag containing randomly distributed nickel particles. A chemical reaction is the control step in the metallurgical process of nickel particles and molten Sn3.5Ag. Originality/value Under the action of the magnetic field, Ni particles in Sn3.5Ag melt will be arranged into columns. With the increase of magnetic field strength, the shorter the time for Ni particles in Sn3.5Ag melt to arrange in a column. With the extension of the service time of the solder joint, if Sn3.5Ag with columnar nickel particles is used as the solder joint material, its microhardness is better than Sn3.5Ag with arbitrarily distributed nickel particles and pure Sn3.5Ag.
{"title":"Effect of external static magnetic field on the particle distribution, the metallurgical process and the microhardness of Sn3.5Ag solder with magnetic Ni particles","authors":"Jianhua Wang, Hongbo Xu, Li Zhou, Ximing Liu, Hongyun Zhao","doi":"10.1108/ssmt-07-2021-0049","DOIUrl":"https://doi.org/10.1108/ssmt-07-2021-0049","url":null,"abstract":"\u0000Purpose\u0000This paper aims to investigate the mechanism of Ni particles distribution in the liquid Sn3.5Ag melt under the external static magnetic field. The control steps of Ni particles and the Sn3.5Ag melt metallurgical process were studied. After aging, the microhardness of pure Sn3.5Ag, Sn3.5Ag containing randomly distributed Ni particles and Sn3.5Ag containing columnar Ni particles were compared.\u0000\u0000\u0000Design/methodology/approach\u0000Place the sample in a crucible for heating. After the sample melts, place a magnet directly above and below the sample to provide a magnetic field. Sn3.5Ag with the different morphological distribution of Ni particles was obtained by holding for different times under different magnetic field intensities. Finally, pure Sn3.5Ag, Sn3.5Ag with random distributed Ni particles and Sn3.5Ag with columnar Ni particles were aged and their microhardness was tested after aging.\u0000\u0000\u0000Findings\u0000The experimental results show that with the increase of magnetic field strength, the time for Ni particle distribution in Sn3.5Ag melt to reach equilibrium is shortened. After aging, the microhardness of Sn3.5Ag containing columnar nickel particles is higher than that of pure Sn3.5Ag and Sn3.5Ag containing randomly distributed nickel particles. A chemical reaction is the control step in the metallurgical process of nickel particles and molten Sn3.5Ag.\u0000\u0000\u0000Originality/value\u0000Under the action of the magnetic field, Ni particles in Sn3.5Ag melt will be arranged into columns. With the increase of magnetic field strength, the shorter the time for Ni particles in Sn3.5Ag melt to arrange in a column. With the extension of the service time of the solder joint, if Sn3.5Ag with columnar nickel particles is used as the solder joint material, its microhardness is better than Sn3.5Ag with arbitrarily distributed nickel particles and pure Sn3.5Ag.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43428450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-28DOI: 10.1108/ssmt-03-2021-0010
Zhao Wang, Yuefeng Li, Zou Jun, Yang Bobo, Shi Mingming
Purpose The purpose of this paper is to investigate the effect of different soldering temperatures on the performance of chip-on-board (COB) light sources during vacuum reflow soldering. Design/methodology/approach First, the influence of the void ratio of the COB light source on the steady-state voltage, luminous flux, luminous efficiency and junction temperature has been explored at soldering temperatures of 250°C, 260°C, 270°C, 280°C and 290°C. The COB chip has also been tested for practical application and aging. Findings The results show that when the soldering temperature is 270°C, the void ratio of the soldering layer is only 5.1%, the junction temperature of the chip is only 76.52°C, and the luminous flux and luminous efficiency are the highest, and it has been observed that the luminous efficiency and average junction temperature of the chip are 107 lm/W and 72.3°C, respectively, which meets the requirements of street lights. After aging for 1,080 h, the light attenuation is 84.64% of the initial value, which indicates that it has higher reliability and longer life. Originality/value It can provide reference data for readers and people in this field and can be directly applied to practical engineering.
{"title":"Effect of different soldering temperatures on the properties of COB light source","authors":"Zhao Wang, Yuefeng Li, Zou Jun, Yang Bobo, Shi Mingming","doi":"10.1108/ssmt-03-2021-0010","DOIUrl":"https://doi.org/10.1108/ssmt-03-2021-0010","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to investigate the effect of different soldering temperatures on the performance of chip-on-board (COB) light sources during vacuum reflow soldering.\u0000\u0000\u0000Design/methodology/approach\u0000First, the influence of the void ratio of the COB light source on the steady-state voltage, luminous flux, luminous efficiency and junction temperature has been explored at soldering temperatures of 250°C, 260°C, 270°C, 280°C and 290°C. The COB chip has also been tested for practical application and aging.\u0000\u0000\u0000Findings\u0000The results show that when the soldering temperature is 270°C, the void ratio of the soldering layer is only 5.1%, the junction temperature of the chip is only 76.52°C, and the luminous flux and luminous efficiency are the highest, and it has been observed that the luminous efficiency and average junction temperature of the chip are 107 lm/W and 72.3°C, respectively, which meets the requirements of street lights. After aging for 1,080 h, the light attenuation is 84.64% of the initial value, which indicates that it has higher reliability and longer life.\u0000\u0000\u0000Originality/value\u0000It can provide reference data for readers and people in this field and can be directly applied to practical engineering.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45076281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-26DOI: 10.1108/ssmt-04-2021-0015
Elwin Heng, M. Z. Abdullah
Purpose This paper focuses on the fluid-structure interaction (FSI) analysis of moisture induced stress for the flip chip ball grid array (FCBGA) package with hydrophobic and hydrophilic materials during the reflow soldering process. The purpose of this paper is to analyze the influence of moisture concentration and FCBGA with hydrophobic material on induced pressure and stress in the package at varies times. Design/methodology/approach The present study analyzed the warpage deformation during the reflow process via visual inspection machine (complied to Joint Electron Device Engineering Council standard) and FSI simulation by using ANSYS/FLUENT package. The direct concentration approach is used to model moisture diffusion and ANSYS is used to predict the Von-Misses stress. Models of Test Vehicle 1 (similar to Xie et al., 2009b) and Test Vehicle 2 (FCBGA package) with the combination of hydrophobic and hydrophilic materials are performed. The simulation for different moisture concentrations with reflows process time has been conducted. Findings The results from the mechanical reliability study indicate that the FSI analysis is found to be in good agreement with the published study and acceptable agreement with the experimental result. The maximum Von-Misses stress induced by the moisture significantly increased on FCBGA with hydrophobic material compared to FCBGA with a hydrophilic material. The presence of hydrophobic material that hinders the moisture desorption process. The analysis also illustrated the moisture could very possibly reside in electronic packaging and developed beyond saturated vapor into superheated vapor or compressed liquid, which exposed electronic packaging to higher stresses. Practical implications The findings provide valuable guidelines and references to engineers and packaging designers during the reflow soldering process in the microelectronics industry. Originality/value Studies on the influence of moisture concentration and hydrophobic material are still limited and studies on FCBGA package warpage under reflow process involving the effect of hydrophobic and hydrophilic materials are rarely reported. Thus, this study is important to effectively bridge the research gap and yield appropriate guidelines in the microelectronics industry.
{"title":"Influence of moisture concentration and hydrophobic material on induced stress in FCBGA package under reflow","authors":"Elwin Heng, M. Z. Abdullah","doi":"10.1108/ssmt-04-2021-0015","DOIUrl":"https://doi.org/10.1108/ssmt-04-2021-0015","url":null,"abstract":"\u0000Purpose\u0000This paper focuses on the fluid-structure interaction (FSI) analysis of moisture induced stress for the flip chip ball grid array (FCBGA) package with hydrophobic and hydrophilic materials during the reflow soldering process. The purpose of this paper is to analyze the influence of moisture concentration and FCBGA with hydrophobic material on induced pressure and stress in the package at varies times.\u0000\u0000\u0000Design/methodology/approach\u0000The present study analyzed the warpage deformation during the reflow process via visual inspection machine (complied to Joint Electron Device Engineering Council standard) and FSI simulation by using ANSYS/FLUENT package. The direct concentration approach is used to model moisture diffusion and ANSYS is used to predict the Von-Misses stress. Models of Test Vehicle 1 (similar to Xie et al., 2009b) and Test Vehicle 2 (FCBGA package) with the combination of hydrophobic and hydrophilic materials are performed. The simulation for different moisture concentrations with reflows process time has been conducted.\u0000\u0000\u0000Findings\u0000The results from the mechanical reliability study indicate that the FSI analysis is found to be in good agreement with the published study and acceptable agreement with the experimental result. The maximum Von-Misses stress induced by the moisture significantly increased on FCBGA with hydrophobic material compared to FCBGA with a hydrophilic material. The presence of hydrophobic material that hinders the moisture desorption process. The analysis also illustrated the moisture could very possibly reside in electronic packaging and developed beyond saturated vapor into superheated vapor or compressed liquid, which exposed electronic packaging to higher stresses.\u0000\u0000\u0000Practical implications\u0000The findings provide valuable guidelines and references to engineers and packaging designers during the reflow soldering process in the microelectronics industry.\u0000\u0000\u0000Originality/value\u0000Studies on the influence of moisture concentration and hydrophobic material are still limited and studies on FCBGA package warpage under reflow process involving the effect of hydrophobic and hydrophilic materials are rarely reported. Thus, this study is important to effectively bridge the research gap and yield appropriate guidelines in the microelectronics industry.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42884007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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