Investigation on fatigue behavior of single SnAgCu/SnPb solder joint by rapid thermal cycling

2015 ◽  
Vol 27 (2) ◽  
pp. 76-83 ◽  
Author(s):  
Jibing Chen ◽  
Yanfang Yin ◽  
Jianping Ye ◽  
Yiping Wu
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Solder Bump ◽  
Fatigue Behavior ◽  
Interfacial Microstructure ◽  
Content Type ◽  
X Ray ◽  
Snpb Solder ◽  
Rapid Thermal Cycling

Purpose – The purpose of this paper is to investigate the thermal fatigue behavior of a single Sn-3.0Ag-0.5Cu (SAC) lead-free and 63Sn-37Pb (SnPb) solder joint treated by rapidly alternating heating and cooling cycles. Design/methodology/approach – With the application of electromagnetic-induced heating, the specimen was heated and cooled, controlled with a system that uses a fuzzy logic algorithm. The microstructure and morphology of the interface between the solder ball and Cu substrate was observed using scanning electron microscopy. The intermetallic compounds and the solder bump surface were analyzed by energy-dispersive X-ray spectroscopy and X-ray diffraction, respectively. Findings – The experimental results showed that rapid thermal cycling had an evident influence on the surface and interfacial microstructure of a single solder joint. The experiment revealed that microcracks originate and propagate on the superficial oxide of the solder bump after rapid thermal cycling. Originality/value – Analysis, based on finite element modeling and metal thermal fatigue mechanism, determined that the rimous cracks can be explained by the heat deformation theory and the function of temperature distribution in materials physics.

Assessment of Relative Thermal Fatigue Life of SAC Lead-Free and Tin-Lead Solders With Custom-Made BGA Assemblies Creating Various Stress Ranges

2009 ◽  
Author(s):  
Y. S. Chan ◽  
C. Yang ◽  
S. W. Ricky Lee
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Relative Magnitude ◽  
Lead Free ◽  
Thermal Fatigue Life ◽  
Snpb Solder ◽  
Custom Made ◽  
Sac Solder

The present study evaluates the relative thermal fatigue life of tin-silver-copper (SnAgCu or SAC) lead-free and tin-lead (SnPb) solders with custom-made BGA assembly configurations generating various stress ranges under thermal cyclic loading. Although the SAC solder bears a lower creep strain rate compared with the SnPb solder in common thermal cycling conditions, it is found that there exits conditions at which the SnPb solder joint maintain a longer life than the SAC solder joint. The determination lies on the maximum normalized equivalent stress levels (σ/E) experienced by the two kinds of solder joint during the temperature cycles. Even under the same straining and thermal cycling condition, it is observed that the maximum σ/E induced in the two kinds of solder joint are normally different, as a result of their different rate of stress relaxation. The analysis shows that both the absolute and relative magnitude of σ/E experienced by the two kinds of solder joint affect the relative life. In general, the SAC solder joint sustain a longer life at low σ/E levels, while the SnPb solder joint outperform the SAC solder joint at high σ/E levels. There exists a critical σ/E level at which both solder joints acquire similar performance. However, this margin shifts with the relative magnitude of σ/E the two kinds of solder joint suffered. Having studied the variation of σ/E for the two kinds of solder joint under various loading conditions, this study uncovers the rationale for the difference in the relative thermal fatigue life of the two kinds of solder joint.

Predicting Thermal Fatigue Lifetimes for SMT Solder Joints

1992 ◽  
Vol 114 (4) ◽  
pp. 472-476 ◽  
Author(s):  
J. Sauber ◽  
J. Seyyedi
Keyword(s):  
Finite Element ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Solder Joints ◽  
Finite Element Models ◽  
Creep Tests ◽  
Creep Equation ◽  
Joint Behavior ◽  
Creep Strains

A power-law type creep equation has been added to finite element models to calculate solder joint response to time, temperature, and stress level. The ability of the models to predict solder joint behavior was verified by running a series of creep tests. The models were then solved to determine the solder joint creep strains which occur during thermal cycling. These creep strains were used to predict the degradation of pull strength resulting from thermal cycling. More than 8,600 solder joints were thermally cycled and then individually pull tested to verify the accuracy of the method.

Analysis of the Interfacial Reaction Between Sn-3.5Ag and Electroplating Interlayers

2005 ◽  
Vol 863 ◽  
Author(s):  
S.M. Yang ◽  
Y.Y. Chang ◽  
Weite Wu
Keyword(s):  
Diffusion Barrier ◽  
Interfacial Microstructure ◽  
X Ray ◽  
Soldering Process ◽  
Free Process ◽  
Snpb Solder ◽  
Microstructure Examination ◽  
Free Solder ◽  
Electroplating Process ◽  
Morphology Characterization

AbstractAt present, Pb-free process is imperative in the electronic packaging industry. Many reports focus on Pb-free solder to improve the solderability, it seems not obtain wettability as good as SnPb solder. In this study, an alloy interlayer with different content was deposited on Cu to balance wettability and diffusion barrier in the interface of joint by electroplating process. There are three types of interlayers including Cu, Ni, and SnNi alloy. The interlayer may react with Sn-3.5Ag solder during reflow process. Sn-Ni alloy plating layer is selected to improve wettability and provide diffusion barrier at the same time in soldering process. For interfacial microstructure examination, morphology characterization can be obtained by using scanning electron microscope (SEM) and energy-dispersive x-ray analysis (EDX). The structure of IMC is identified by x-ray diffraction (XRD).

SAC–xTiO2 nano-reinforced lead-free solder joint characterizations in ultra-fine package assembly

2018 ◽  
Vol 30 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Fakhrozi Che Ani ◽  
Azman Jalar ◽  
Abdullah Aziz Saad ◽  
Chu Yee Khor ◽  
Roslina Ismail ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Solder Joint ◽  
Solder Joints ◽  
Ion Beam ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Paste ◽  
Content Type ◽  
X Ray ◽  
Free Solder

Purpose This paper aims to investigate the characteristics of ultra-fine lead-free solder joints reinforced with TiO2 nanoparticles in an electronic assembly. Design/methodology/approach This study focused on the microstructure and quality of solder joints. Various percentages of TiO2 nanoparticles were mixed with a lead-free Sn-3.5Ag-0.7Cu solder paste. This new form of nano-reinforced lead-free solder paste was used to assemble a miniature package consisting of an ultra-fine capacitor on a printed circuit board by means of a reflow soldering process. The microstructure and the fillet height were investigated using a focused ion beam, a high-resolution transmission electron microscope system equipped with an energy dispersive X-ray spectrometer (EDS), and a field emission scanning electron microscope coupled with an EDS and X-ray diffraction machine. Findings The experimental results revealed that the intermetallic compound with the lowest thickness was produced by the nano-reinforced solder with a TiO2 content of 0.05 Wt.%. Increasing the TiO2 content to 0.15 Wt.% led to an improvement in the fillet height. The characteristics of the solder joint fulfilled the reliability requirements of the IPC standards. Practical implications This study provides engineers with a profound understanding of the characteristics of ultra-fine nano-reinforced solder joint packages in the microelectronics industry. Originality/value The findings are expected to provide proper guidelines and references with regard to the manufacture of miniaturized electronic packages. This study also explored the effects of TiO2 on the microstructure and the fillet height of ultra-fine capacitors.

Reliability Evaluation of BGA Solder Joints by Using Thermal Fatigue Models

2005 ◽  
Author(s):  
Ouk Sub Lee ◽  
No Hoon Myoung ◽  
Dong Hyeok Kim
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Failure Probability ◽  
Solder Joints ◽  
State Function ◽  
Mechanical Loads ◽  
First Order ◽  
Reliability Method ◽  
Fatigue Model

The use of Ball Grid Array (BGA) interconnects utilizing the BGA solder joint has grown rapidly because of its small volume and diversity of its application. Therefore, the continuous quantification and refinement of BGA solder joint in terms of its reliability are required. The creep and cyclically applied mechanical loads generally cause metal fatigue on the BGA solder joint which inevitably leads to an electrical discontinuity. In the field application, the BGA solder joints are known to experience mechanical loads during temperature changes caused by power up/down events as the result of the Coefficient of Thermal Expansion (CTE) mismatch between the substrate and the Si die. In this paper, extremely small resistance changes in the lead free joints corresponding to the through-cracks generated by the thermal fatigue were measured and the failure was defined in terms of anomalous changes in the joint resistance. Furthermore, the reliability of BGA solder joints under thermal cycling was evaluated by using a criterion that may define and distinguish a failure in the solder joint. Any changes in circuit resistance according to the accumulated damage induced by the thermal cycling in the joint were recorded and evaluated by the First Order Reliability Method (FORM) procedure in order to quantify the reliability of solder joint. The first order Taylor series expansion of the limit state function incorporating with thermal fatigue models is used in order to estimate the failure probability of solder joints under heated condition. Various thermal fatigue models are utilized in this study. Models based on various plastic-strain rates such as Coffin-Manson fatigue model, total strain fatigue model and Solomon fatigue model are utilized in this study. The effects of random variables such as the CTE, the pitch of solder joint, the diameter of solder joint, and the CTE difference solder joints on the failure probability of the solder joint are systematically investigated by using a failure probability model with the FORM.

The size effect on intermetallic microstructure evolution of critical solder joints for flip chip assemblies

2015 ◽  
Vol 27 (4) ◽  
pp. 178-184 ◽  
Author(s):  
Ye Tian ◽  
Justin Chow ◽  
Xi Liu ◽  
Suresh K. Sitaraman
Keyword(s):  
Solder Joint ◽  
Design Methodology ◽  
Growth Process ◽  
Flip Chip ◽  
Solder Bump ◽  
Solder Joints ◽  
Solder Matrix ◽  
Industrial Practice ◽  
Content Type ◽  
Flip Chips

Purpose – The purpose of this paper is to study the intermetallic compound (IMC) thickness, composition and morphology in 100-μm pitch and 200-μm pitch Sn–Ag–Cu (SAC305) flip-chip assemblies after bump reflow and assembly reflow. In particular, emphasis is placed on the effect of solder joint size on the interfacial IMCs between metal pads and solder matrix. Design/methodology/approach – This work uses 100-μm pitch and 200-μm pitch silicon flip chips with nickel (Ni) pads and stand-off height of approximately 45 and 90 μm, respectively, assembled on substrates with copper (Cu) pads. The IMCs evolution in solder joints was investigated during reflow by using 100- and 200-μm pitch flip-chip assemblies. Findings – After bump reflow, the joints size controls the IMC composition and dominant IMC type as well as IMC thickness and also influences the dominant IMC morphology. After assembly reflow, the cross-reaction of the pad metallurgies promotes the dominant IMC transformation and shape coarsened on the Ni pad interface for smaller joints and promotes a great number of new dominate IMC growth on the Ni pad interface in larger joints. On the Cu pad interface, many small voids formed in the IMC in larger joints, but were not observed in smaller joints, combined with the drawing of the IMC growth process. Originality/value – With continued advances in microelectronics, it is anticipated that next-generation microelectronic assemblies will require a reduction of the flip-chip solder bump pitch to 100 μm or less from the current industrial practice of 130 to150 μm. This work shows that as the packaging size reduced with the solder joint interconnection, the solder size becomes an important factor in the intermetallic composition as well as morphology and thickness after reflow.

scholarly journals Thermal Fatigue Model of Aluminium Alloy Die Casting H-13 Dies under Thermo-Mechanical Cycle

Mechanika ◽  
2021 ◽  
Vol 27 (5) ◽  
pp. 385-391
Author(s):  
Ghusoon Ridha Mohammed Ali ◽  
Ethar Mohammed Mubarak ◽  
Basim Hussein Abbas
Keyword(s):  
Thermal Cycling ◽  
Fatigue Resistance ◽  
Thermal Fatigue ◽  
Fatigue Behavior ◽  
Die Casting ◽  
Thermal Conditions ◽  
Thermal Fatigue Resistance ◽  
Heating And Cooling ◽  
Mechanical Cycling ◽  
Fatigue Model

In industrial fields, thermal fatigue behavior has recently acquired an important role which is mainly related to the interaction between mechanical and thermal conditions. This paper proposes a thermal fatigue model of H13 tool steel under thermos-mechanical cycles. A test apparatus was used to assess the thermal fatigue resistance of materials to estimate surface crack area when specimens are subjected to thermal cycling. Thermal cycling up to 700°C was used, and crack patterns were examined after 1850, 3000, and 5000 cycles. Temperature distributions were measured at different locations in the test specimens. A model was developed to establish a relationship between mechanical cycling and thermal analysis. From the results, the thermal fatigue resistance was significantly improved over the control parameter after heating and cooling during thermomechanical cycles. The model was applied to determine the best performance and in-service life of die casting tools.

scholarly journals Establishment of new design criteria for GlidCop® X-ray absorbers

2017 ◽  
Vol 24 (2) ◽  
pp. 402-412
Author(s):  
Jeff T. Collins ◽  
Jeremy Nudell ◽  
Gary Navrotski ◽  
Zunping Liu ◽  
Patric Den Hartog
Keyword(s):  
Thermal Fatigue ◽  
Research Program ◽  
Thermal Loading ◽  
Fatigue Behavior ◽  
Parametric Models ◽  
Beam Power ◽  
Design Criteria ◽  
Element Analysis ◽  
X Ray ◽  
Fatigue Model

An engineering research program has been conducted at the Advanced Photon Source (APS) in order to determine the thermomechanical conditions that lead to crack formation in GlidCop®, a material commonly used to fabricate X-ray absorbers at X-ray synchrotron facilities. This dispersion-strengthened copper alloy is a proprietary material and detailed technical data of interest to the synchrotron community is limited. The results from the research program have allowed new design criteria to be established for GlidCop® X-ray absorbers based upon the thermomechanically induced fatigue behavior of the material. X-ray power from APS insertion devices was used to expose 30 GlidCop® samples to 10000 thermal loading cycles each under various beam power conditions, and all of the samples were metallurgically examined for crack presence/geometry. In addition, an independent testing facility was hired to measure temperature-dependent mechanical data and uniaxial mechanical fatigue data for numerous GlidCop® samples. Data from these studies support finite element analysis (FEA) simulation and parametric models, allowing the development of a thermal fatigue model and the establishment of new design criteria so that the thermomechanically induced fatigue life of X-ray absorbers may be predicted. It is also demonstrated how the thermal fatigue model can be used as a tool to geometrically optimize X-ray absorber designs.

Thermal Cycling Analysis of BGA Solder Joint Reliability

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 000542-000553
Author(s):  
Betty H. Yeung ◽  
Torsten Hauck ◽  
Brett Wilkerson ◽  
Thomas Koschmieder
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
High Reliability ◽  
Fatigue Behavior ◽  
Temperature Cycling ◽  
Fractional Factorial ◽  
Sphere Diameter ◽  
Surface Evolver ◽  
Solder Joint Reliability ◽  
Joint Reliability

The solder joint reliability of semiconductor package interconnects is critical to product durability. A dominant failure mode is solder fatigue due to the CTE mismatch between BGA component and PCB at thermal cycling. It is well known that besides thermal expansion mismatch of component and board, the solder joint geometry has a great impact on fatigue behavior and time to failure. In this study, a combination of Surface Evolver and finite element analysis are use to predict the solder joint shapes for the assembly of medium pin count BGA's and to estimate the reliability at accelerated temperature cycling conditions. Results of Surface Evolver are compared with the assumption of a truncated sphere. The solder shape predictions are applied for a subsequent thermo-mechanical analysis of the BGA assembly. Inelastic creep deformation is evaluated for critical solder balls, and the Coffin-Manson relation is used to estimate the solder joint lifetime. The entire simulation procedure will be demonstrated for a product design study for high reliability automotive BGA's. A fractional factorial design is defined that considers solder sphere diameter and solder pad sizes on BGA substrate and on PCB side. Resulting creep values and lifetime estimates will be compared.

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