A Systems Approach to Solder Joint Fatigue in Spacecraft Electronic Packaging

1991 ◽  
Vol 113 (2) ◽  
pp. 121-128 ◽  
Author(s):  
R. G. Ross
Keyword(s):  
Solder Joint ◽  
Electronic Packaging ◽  
Thermal Cycle ◽  
Systems Approach ◽  
High Reliability ◽  
Temperature Cycling ◽  
Failure Behavior ◽  
Acceptance Test ◽  
Solder Fatigue ◽  
Solder Joint Fatigue

Differential expansion induced fatigue resulting from temperature cycling is a leading cause of solder joint failures in spacecraft. Achieving high reliability flight hardware requires that each element of the fatigue issue be addressed carefully. This includes defining the complete thermal-cycle environment to be experienced by the hardware, developing electronic packaging concepts that are consistent with the defined environments, and validating the completed designs with a thorough qualification and acceptance test program. This paper describes a useful systems approach to solder fatigue based principally on the fundamental log-strain versus log-cycles-to-failure behavior of fatigue. This fundamental behavior has been useful to integrate diverse ground test and flight operational thermal-cycle environments into a unified electronics design approach. Each element of the approach reflects both the mechanism physics that control solder fatigue, as well as the practical realities of the hardware build, test, delivery, and application cycle.

DIC Based Investigation Into the Effect of Mean Temperature of Thermal Cycle on the Strain State in SnAgCu Solder Joint

2015 ◽  
Author(s):  
Pradeep Lall ◽  
Kazi Mirza ◽  
Jeff Suhling
Keyword(s):  
Solder Joint ◽  
Thermal Fatigue ◽  
Thermal Cycle ◽  
Strain State ◽  
High Reliability ◽  
Image Correlation ◽  
Harsh Environment ◽  
Fatigue Reliability ◽  
Mean Temperature ◽  
Solder Joint Fatigue

Electronics in high reliability applications may be subjected to cyclic thermo-mechanical loads after being deployed for extended periods of time in harsh environment. Cyclic thermal excursion may result in solder joint fatigue leading to failure. Previous researchers have shown that exposure to high temperature for extended periods of time results in evolution of the mechanical properties of SnAgCu alloys. Deployment of leadfree electronics in harsh environment applications may result in exposure to a multitude of thermal cycles. The effect of cyclic thermal range and thermal aging on the thermal fatigue reliability has been widely documented; however the effect of the mean temperature on the thermal fatigue reliability and the strain evolution of during cyclic exposure has not been studied. In this paper, an experimental investigation has been undertaken using digital image correlation to quantify the evolution in the strain state under different mean temperatures and cyclic thermal intervals. Three different test vehicles, BGA 144, 256 and 324 were used in this study under three different test conditions 50–150°C, 0–100°C and −50–50°C. A framework to evaluate the effect of mean temperature of thermal cycle has been developed.

The Effect of Intermetallic Compound in Solder Joint Fatigue Life Prediction Using Finite Element Modeling

2003 ◽  
Author(s):  
Mohammad Masum Hossain ◽  
Dereje Agonafer ◽  
Puligandla Viswanadham ◽  
Tommi Reinikainen
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Finite Element Modeling ◽  
Life Prediction ◽  
Temperature Cycling ◽  
Fatigue Life Prediction ◽  
Element Modeling ◽  
Solder Joint Fatigue

The life-prediction modeling of an electronic package requires a sequence of critical assumptions concerning the finite element models. The solder structures accommodate the bulk of the plastic strain that is generated during accelerated temperature cycling due to the thermal expansion mismatch between the various materials that constitute the package. Finite element analysis is extensively used for simulating the effect of accelerated temperature cycling on electronic packages. There are a number of issues that need to be addressed to improve the current FEM models. One of the limitations inherent to the presently available models is the accuracy in property values of eutectic 63Sn/37Pb solder or other solder materials (i.e. 62Sn/36Pb/2Ag). Life prediction methodologies for high temperature solders (90Pb/10Sn, 95Pb/5Sn, etc.) or lead-free based inter-connects materials, are almost non-existent due to their low volume use or relative infancy. [1] Another major limitation for the models presently available is excluding the effect of intermetallic compound (Cu6Sn5, Cu3Sn) formation and growth between solder joint and Cu pad due to the reflow processes, rework and during the thermal aging. The mechanical reliability of these intermetallic compounds clearly influences the mechanical integrity of the interconnection. The brittle failures of solder balls have been identified with the growth of a number of intermetallic compounds both at the interfaces between metallic layers and in the bulk solder balls. In this paper, the effect of intermetallic compound in fatigue life prediction using finite element modeling is described. A Chip Scale Package 3D Quarter model is chosen to do the FE analysis. Accelerated temperature cycling is performed to obtain the plastic work due to thermal expansion mismatch between the various materials. Solder joint fatigue life prediction methodologies were incorporated so that finite element simulation results were translated into estimated cycles to failure. The results are compared with conventional models that do not include intermetallic effects. Conventionally available material properties are assumed for the eutectic 63Sn/37Pb solder and the intermetallic material properties. The importance of including intermetallic effect in finite element modeling will be discussed.

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.

scholarly journals Probabilistic methodology for reliability assessment of electronic packages

2019 ◽  
Vol 286 ◽  
pp. 02002
Author(s):  
H. Hamdani ◽  
B. Radi ◽  
A. El Hami
Keyword(s):  
Solder Joint ◽  
Reliability Assessment ◽  
Temperature Cycling ◽  
Time Dependent ◽  
Electronic Packages ◽  
Finite Element Analyses ◽  
Material Parameters ◽  
Joint Reliability ◽  
Design Variables ◽  
Solder Joint Fatigue

In the mechatronic devices, the finite element analyses are the most used method to determine time-dependent solder joint fatigue response under accelerated temperature cycling conditions, the deterministic analyses are the most used methods. However, the design variables show variability and randomness which will affect the lifetime prediction quality. This paper focuses on solder joint reliability in tape-based chip-scale packages(CSP) with the consideration of uncertainties in material parameters.

Solders Fatigue Prediction Using Interfacial Boundary Volume Criterion

2003 ◽  
Vol 125 (4) ◽  
pp. 582-588 ◽  
Author(s):  
X. J. Zhao ◽  
G. Q. Zhang ◽  
J. F. J. M. Caers ◽  
L. J. Ernst
Keyword(s):  
Solder Joint ◽  
Wafer Level ◽  
Plastic Strain Range ◽  
Damage Criterion ◽  
Component Size ◽  
Model Based ◽  
Fatigue Model ◽  
Interfacial Boundary ◽  
Solder Fatigue ◽  
Solder Joint Fatigue

In this paper, an “interfacial boundary volume” based damage criterion was proposed in combination with the modified Coffin-Manson model to predict solder fatigue. This criterion assumes that mainly, the behavior of the thin solder layer at chip pad interface contributes to the solder fatigue, not the whole solder joint or the averaged strains from randomly selected elements. The damage parameter was thus calculated by averaging the visco-plastic strain range over the interfacial boundary layer volume in the solder and later related to the corresponding fatigue life of experimental test through least-squares curves fitting to determine the empirical coefficients in the Coffin-Manson equation. As a demonstrator, the solder joint fatigue in wafer level chip scale packaging under thermal shock loading was analyzed. An appropriate constitutive relation from Darveaux was used to model the inelastic deformation of the solder alloy, and the different stress-strain responses resulting from different designs were calculated. The analysis results were used to develop the empirical fatigue model based on the interfacial boundary volume damage criterion and then this fatigue model was used for prediction. The fatigue lives of chip scale packaging with variable solder land size and component size were analyzed using this model. The prediction results match well with those from experimental tests. For this demonstrator, it was also shown that the empirical model based on the interfacial boundary volume criterion was more accurate than the models obtained from other strain averaging methods.

A Comparative Study of the Solder Joint Reliability in Flip Chip Assemblies with Compliant and Rigid Substrates

2007 ◽  
Vol 353-358 ◽  
pp. 2932-2935
Author(s):  
Yong Cheng Lin ◽  
Xu Chen ◽  
Xing Shen Liu ◽  
Guo Quan Lu
Keyword(s):  
Solder Joint ◽  
Fatigue Failure ◽  
Flip Chip ◽  
Solder Joints ◽  
Temperature Cycling ◽  
Failure Behavior ◽  
Stress Strain ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
Failure Life

The reliability of solder joints in flip chip assemblies with both compliant (flex) and rigid (PCB) substrates was studied by accelerated temperature cycling tests and finite element modeling (FEM). In-process electrical resistance measurements and nondestructive evaluations were conducted to monitor solder joint failure behavior, hence the fatigue failure life. Meanwhile, the predicted fatigue failure life of solder joints was obtained by Darveaux’s crack initiation and growth models. It can be concluded that the solder joints in flip chip on flex assembly (FCOF) have longer fatigue life than those in flip chip on rigid board assembly (FCOB); the maximum von Mises stress/strain and the maximum shear stress/strain of FCOB solder joints are much higher than those of FCOF solder joints; the thermal strain and stress in solder joints is reduced by flex buckling or bending and flex substrate could dissipate energy that otherwise would be absorbed by solder joint. Therefore, the substrate flexibility has a great effect on solder joint reliability and the reliability improvement was attributed to flex buckling or bending during temperature cycling.

A Modeling Study of the Effect of Underfill Materials on Solder Joint Thermal Fatigue of Ball Grid Array Package

2014 ◽  
Author(s):  
Wei Wang ◽  
Tung Nguyen
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Young’S Modulus ◽  
Material Properties ◽  
Young's Modulus ◽  
Ball Grid Array ◽  
Temperature Cycling ◽  
Solder Joint Fatigue ◽  
Underfill Material

Flip Chip Ball Grid Array packages (FCBGA) have been widely used in microelectronic industry in integrated circuit (IC) packages. Due to the intrinsic mismatch of the coefficient of thermal expansion (CTE) between silicon chip and Printed Circuit Board (PCB) material, solder joint fatigue failure due to thermal cycling becomes the most important concern for this technology. Underfill materials have been widely used as a solution to improving solder joint fatigue life. It is of importance to understand the effect of underfill material properties on the solder joint fatigue life. In this study, finite element method (FEM) was employed to study the effect of underfill materials on solder joint low cycle fatigue life in thermal cycling. ANSYS code was used to calculate the inelastic energy density generated in temperature cycling. The viscoplastic model was used for the solder to consider the inelastic and time dependent behavior under thermal cycling. By using the FEM model, the underfill material properties, the Young’s modulus and CTE were examined to study their effects on the solder joint fatigue life. It was found that the improvement of solder fatigue life could be achieved only when the CTE was low. This improvement could be strengthened by large Young’s modulus to increase the solder strength. In contrast, a large CTE underfill material could deepen the solder joint fatigue damage. This worsening effect became more significant as the Young’s modulus became larger. This study could serve as a foundation for understanding the mechanism of solder joint fatigue in the presence of underfill materials and provide guidance to choose appropriate underfill materials to improve BGA solder joint thermal fatigue in temperature cycling.

Heat Sink Induced Thermo-Mechanical Joint Strain in QFN Devices

2013 ◽  
Vol 2013 (1) ◽  
pp. 000467-000472
Author(s):  
Gerard McVicker ◽  
Vijay Khanna ◽  
Sri M. Sri-Jayantha
Keyword(s):  
Solder Joint ◽  
Heat Sink ◽  
Power Distribution ◽  
Strain Energy ◽  
Heat Dissipation ◽  
Coefficient Of Thermal Expansion ◽  
Inelastic Strain ◽  
Temperature Cycling ◽  
Image Correlation ◽  
Solder Joint Fatigue

A Blade Server System (BSS) utilizes Voltage Regulator Modules (VRM), in the form of Quad Flat No-Lead (QFN) devices, to provide power distribution to various components on the system board. Depending on the power requirements of the circuit, these VRM's can be mounted as single devices or banked together. In addition, the power density of the VRM can be high enough to warrant heat dissipation through the use of a heat sink. Typically, during field conditions (FC) the BSS are powered on and off up to four times per day, with their ambient temperature cycling between 25°C and 80°C. This cyclical temperature gradient drives inelastic strain in the solder joints due to the coefficient of thermal expansion (CTE) mismatch between the QFN and the circuit card. In addition, the heat sink, coupled to the QFN and the circuit card, can induce additional inelastic solder joint strain, resulting in early solder joint fatigue failure. To understand the effect of the heat sink mounting, a FEM (Finite Element Model) of four QFN's mounted to a BSS circuit card was developed. The model was exercised to calculate the maximum strain energy in a critical joint, due to the cyclical straining, and the results were compared for a QFN with and without a heat sink. It was determined that the presence of the heat sink did contribute to higher strain energy and therefore could lead to earlier joint failure. While the presence of the heat sink is required, careful design of the mounting should be employed to provide lateral slip, essentially decoupling the heat sink from the QFN joint strain. Details of the modeling and results, along with DIC (Digital Image Correlation) measurements of heat sink lateral slip, are presented.

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