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.

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.

Reliability Simulations for Solder Joints Using Stochastic Finite Element and Artificial Neural Network Models

1996 ◽  
Vol 118 (3) ◽  
pp. 148-156 ◽  
Author(s):  
G. Subbarayan ◽  
Y. Li ◽  
R. L. Mahajan
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Finite Element ◽  
Solder Joint ◽  
Six Sigma ◽  
Manufacturing Process ◽  
Solder Joints ◽  
Finite Element Models ◽  
Process Tolerance ◽  
Reliability Of Solder Joints

The field reliability of solder joints depends on the manufacturing process tolerance of design parameters and on the capability of manufacturing processes to achieve the tolerance. This process capability is usually expressed through measures such as “six-sigma.” In this paper, a systematic procedure to estimate the reliability of solder joints due to manufacturing process induced variations on the design is presented. The reliability is calculated using the stochastic finite element method and is most naturally expressed in terms of a mean life and a standard deviation in life. An integrated finite element solution procedure for predicting solder joint profile (during reflow) and life is also presented in the paper. A physico-neural approach in which the finite element models are used to build an artificial neural network model is next developed to combine the accuracy of the finite element models with the computational efficiency of neural networks. This physico-neural approach is shown to reduce the computational time required per design evaluation by four orders of magnitude without significant loss of accuracy. The developed procedures are applied to the 72 I/O OMPAC BGA package from Motorola, Inc. It is shown that a ±10 percent process tolerance on solder joint height, volume and pad sizes with a “six-sigma” process capability on these variables will result in solder joint with over ±20 percent variations in life about the mean life at ±6σ level. It is also shown that variations in life of BGA solder joints are most sensitive to variations in solder joint height. Variations in PWB pad size, solder volume, and substrate pad size are relatively less important, but in the order listed.

Strategies for Improving Reliability of Solder Joints on Power Semiconductor Devices

2003 ◽  
Author(s):  
Guo-Quan Lu ◽  
Xingsheng Liu ◽  
Sihua Wen ◽  
Jesus Noel Calata ◽  
John G. Bai
Keyword(s):  
Finite Element ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Flip Chip ◽  
Solder Joints ◽  
Mechanical Stresses ◽  
Flexible Substrates ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
Reliability Of Solder Joints

There has been a significant research effort on area-array flip-chip solder joint technology in order to reduce package footprint, enhance current handling capability, and improve heat dissipation. However, there is a lingering concern over cyclic fatigue of solder alloys by thermo-mechanical stresses arising from mismatched thermal expansion coefficients of expansion among the various components of the package. In this paper, some strategies taken to improve the reliability of solder joints on power devices in single-device and multi-chip packages are presented. A strategy for improving solder joint reliability by adjusting solder joint geometry, underfilling and utilization of flexible substrates is discussed with emphasis on triple-stacked solder joints that resemble the shape of an hourglass. The hourglass shape relocates the highest inelastic strain away from the weaker interface with the chip to the bulk region of the joint while the underfill provides a load transfer from the joints. Flexible substrates can deform to relieve thermo-mechanical stresses. Thermal cycling data show significant improvements in reliability when these techniques are used. The design, testing, and finite-element analyses of an interconnection structure, termed the Dimple-Array Interconnect (DAI), for improving the solder joint reliability is also presented. In the DAI structure, a solder is used to join arrays of dimples pre-formed on a metal sheet onto the bonding pads of a device. Finite-element thermo-mechanical analyses and thermal cycling data show that the dimple-array solder joints are more fatigue-resistant than the conventional barrel-shaped solder joints in flip-chip IC packages.

Application of Finite Element Method in Optimal Design of Flip-Chip Package

2011 ◽  
Vol 264-265 ◽  
pp. 1660-1665
Author(s):  
Yong Cheng Lin ◽  
Yu Chi Xia
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Fatigue ◽  
Flip Chip ◽  
Solder Joints ◽  
Temperature Cycling ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder

More and more solder joints in circuit boards and electronic products are changing to lead free solder, placing an emphasis on lead free solder joint reliability. Solder joint fatigue failure is a serious reliability concern in area array technologies. In this study, the effects of substrate materials on the solder joint thermal fatigue life were investigated by finite element model. Accelerated temperature cycling loading was imposed to evaluate the reliability of solder joints. The thermal strain/stress in solder joints of flip chip assemblies with different substrates was compared, and the fatigue life of solder joints were evaluated by Darveaux’s crack initiation and growth model. The results show the mechanisms of substrate flexibility on improving solder joint thermal fatigue.

A Finite Element Study of Factors Affecting Fatigue Life of Solder Joints

1994 ◽  
Vol 116 (4) ◽  
pp. 265-273 ◽  
Author(s):  
N. Paydar ◽  
Y. Tong ◽  
H. U. Akay
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Hold Time ◽  
Strain Range ◽  
Cycle Life ◽  
Finite Element Program ◽  
Factors Affecting

The elastic-plastic-creep characteristics of solder joints are implemented in a nonlinear finite element program ABAQUS by developing user defined material subroutines. An eutectic Pb-Sn solder joint of a resistor carrier under thermal cycling between 125°C and −55°C is modeled, and the effect of various parameters on the solder joint cycle life is evaluated. The strain range of the solder joint under thermal cycling loads is calculated, which is then converted into solder joint cycle life through a fatigue-life relationship proposed by Engelmaier (1983). The parameters studied include: ramp time, hold time, grain size, initial temperature, constitutive equations, material properties for solder alloys, and mesh refinement. The effects of these variations on the fatigue life of solder joints are illustrated. The described method can serve as a tool in the design and manufacturing of surface-mount (SMT) assemblies.

scholarly journals Study on the Reliability of Sn–Bi Composite Solder Pastes with Thermosetting Epoxy under Thermal Cycling and Humidity Treatment

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 733
Author(s):  
Lu Liu ◽  
Songbai Xue ◽  
Ruiyang Ni ◽  
Peng Zhang ◽  
Jie Wu
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Composite Solder ◽  
Solder Joints ◽  
Solder Paste ◽  
Epoxy System ◽  
Mechanical Reinforcement ◽  
Microstructure Observation ◽  
Temperature And Humidity ◽  
Thermosetting Epoxy

In this study, a Sn–Bi composite solder paste with thermosetting epoxy (TSEP Sn–Bi) was prepared by mixing Sn–Bi solder powder, flux, and epoxy system. The melting characteristics of the Sn–Bi solder alloy and the curing reaction of the epoxy system were measured by differential scanning calorimeter (DSC). A reflow profile was optimized based on the Sn–Bi reflow profile, and the Organic Solderability Preservative (OSP) Cu pad mounted 0603 chip resistor was chosen to reflow soldering and to prepare samples of the corresponding joint. The high temperature and humidity reliability of the solder joints at 85 °C/85% RH (Relative Humidity) for 1000 h and the thermal cycle reliability of the solder joints from −40 °C to 125 °C for 1000 cycles were investigated. Compared to the Sn–Bi solder joint, the TSEP Sn–Bi solder joints had increased reliability. The microstructure observation shows that the epoxy resin curing process did not affect the transformation of the microstructure. The shear force of the TSEP Sn–Bi solder joints after 1000 cycles of thermal cycling test was 1.23–1.35 times higher than the Sn–Bi solder joint and after 1000 h of temperature and humidity tests was 1.14–1.27 times higher than the Sn–Bi solder joint. The fracture analysis indicated that the cured cover layer could still have a mechanical reinforcement to the TSEP Sn–Bi solder joints after these reliability tests.

scholarly journals Prediction of Thermal Fatigue Life of Lead-Free BGA Solder Joints by Finite Element Analysis

2001 ◽  
Vol 42 (5) ◽  
pp. 809-813 ◽  
Author(s):  
Young-Eui Shin ◽  
Kyung-Woo Lee ◽  
Kyong-Ho Chang ◽  
Seung-Boo Jung ◽  
Jae Pil Jung
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Thermal Fatigue ◽  
Solder Joints ◽  
Lead Free ◽  
Element Analysis ◽  
Thermal Fatigue Life

Accurate composition dependent thermo mechanical lifetime estimation of hour glass type solder joint in electronic assemblies

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Leonid Anatolevich Olenev ◽  
Rafina Rafkatovna Zakieva ◽  
Nina Nikolaevna Smirnova ◽  
Rustem Adamovich Shichiyakh ◽  
Kirill Aleksandrovich Ershov ◽  
...  
Keyword(s):  
Finite Element ◽  
Chemical Composition ◽  
Solder Joint ◽  
Design Methodology ◽  
Lifetime Estimation ◽  
Creep Tests ◽  
Content Type ◽  
Element Simulation ◽  
Glass Type ◽  
Electronic Assemblies

Purpose This study aims to present a more accurate lifetime prediction model considering solder chemical composition. Design/methodology/approach Thermal cycling and standard creep tests as well as finite element simulation were used. Findings The study found lower error in the solder joint lifetime evaluation. The higher the Ag content is, the higher the lifetime is achieved. Originality/value It is confirmed.

scholarly journals Prediction of mechanical properties and fatigue life of nano silver paste in chip interconnection

2020 ◽  
Author(s):  
Hui YANG ◽  
Jihui Wu
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Stress And Strain ◽  
Nano Silver ◽  
Finite Element Software ◽  
Flip Chips ◽  
Empirical Correction ◽  
Prediction Of Mechanical Properties

Abstract The simulation of nano-silver solder joints in flip-chips is performed by the finite element software ANSYS, and the stress-strain distribution results of the solder joints are displayed. In this simulation, the solder joints use Anand viscoplastic constitutive model, which can reasonably simulate the stress and strain of solder joints under thermal cycling load. At the same time this model has been embedded in ANSYS software, so it is more convenient to use. The final simulation results show that the areas where the maximum stresses and strains occur at the solder joints are mostly distributed in the contact areas between the solder joints and the copper pillars and at the solder joints. During the entire thermal cycling load process, the area where the maximum change in stress and strain occurs is always at the solder joint, and when the temperature changes, the temperature at the solder joint changes significantly. Based on comprehensive analysis, the relevant empirical correction calculation equation is used to calculate and predict the thermal fatigue life of nano-silver solder joints. The analysis results provide a reference for the application of nano-silver solder in the electronic packaging industry.

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