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Proceedings ArticleDOI

Thermal fatigue reliability enhancement of plastic ball grid array (PBGA) packages

28 May 1996-pp 1211-1216
TL;DR: In this article, a combined design of experiment and numerical analysis approach is used to determine the effect of four design parameters on the thermal fatigue life of solder joints, including substrate thickness, array configuration, ball pitch, acid pad size.
Abstract: A combined design of experiment and numerical analysis approach is used to determine the effect of four design parameters on the thermal fatigue life of solder joints. The four parameters considered were: substrate thickness, array configuration, ball pitch, acid pad size. A full factorial experiment was designed which was conducted numerically. A validated life prediction model was then used to determine the fatigue lives for each combination. Up to a factor of five improvement in fatigue life is predicted when these parameters were changed from one level to another.
Citations
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Journal ArticleDOI
TL;DR: A review of fourteen solder joint fatigue models is presented in this article with an emphasis on summarizing the features and applications of each fatigue model, and two fatigue model application scenarios are discussed.

487 citations


Cites background from "Thermal fatigue reliability enhance..."

  • ...The very nature of solder lends itself to creep deformation and so must be accounted for....

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Journal ArticleDOI
TL;DR: In this article, the reliability of fine-pitch plastic ball grid array (PBGA) packages has been evaluated in the automotive underhood environment, and the results showed that the CBGAs are more likely to fail at high T/sub g/ substrates with glass transition temperatures much higher than the 125/spl deg/C high temperature limit.
Abstract: Fine-pitch ball grid array (BGA) and underfills have been used in benign office environments and wireless applications for a number of years, however their reliability in automotive underhood environment is not well understood. In this work, the reliability of fine-pitch plastic ball grid array (PBGA) packages has been evaluated in the automotive underhood environment. Experimental studies indicate that the coefficient of thermal expansion (CTE) as measured by thermomechanical analyzer (TMA) typically starts to change at 10-15/spl deg/C lower temperature than the T/sub g/ specified by differential scanning calorimetry (DSC) potentially extending the change in CTE well into the accelerated test envelope in the neighborhood of 125/spl deg/C. High T/sub g/ substrates with glass-transition temperatures much higher than the 125/spl deg/C high temperature limit, are therefore not subject to the effect of high coefficient of thermal expansion close to the high temperature of the accelerated test. Darveaux's damage relationships were derived on ceramic ball grid array (CBGA) assemblies, with predominantly solder mask defined (SMD) pads and 62Sn36Pb2Ag solder. In addition to significant differences in the crack propagation paths for the two pad constructions, SMD pads fail significantly faster than the non solder mask defined (NSMD) pads in thermal fatigue. The thermal mismatch on CBGAs is much larger than PBGA assemblies. Crack propagation in CBGAs is often observed predominantly on the package side as opposed to both package and board side for PBGAs. In the present study, crack propagation data has been acquired on assemblies with 15, 17, and 23mm size plastic BGAs with NSMD pads and 63Sn37Pb on high-T/sub g/ printed circuit boards. The data has been benchmarked against Darveaux's data on CBGA assemblies. Experimental matrix also encompasses the effect of bis-maleimide triazine (BT) substrate thickness on reliability. Damage constants have been developed and compared against existing Darveaux Constants. Prediction error has been quantified for both sets of constants.

138 citations


Cites background or methods from "Thermal fatigue reliability enhance..."

  • ...Syed [5] tested 23 mm components, and examined several parameters including BT substrate thickness, solder pad...

    [...]

  • ...However, 40 to 125 C thermal cycling tests performed recently by several investigators [5]–[7] have demonstrated that properly designed larger BGAs (e....

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Journal Article
TL;DR: In this article, the effect of die size, die thickness, solder joint geometry and underfill properties on predicted solder fatigue has been investigated for flip-chip assemblies with and without underfill, with no significant difference seen between fatigue lives of underfilled ceramic and organic assembled devices.
Abstract: A solder fatigue model for the 63Sn/Pb solder alloy has been previously introduced which characterizes the creep fatigue phenomena of the solder by combining nonlinear finite element modelling with experimental thermal fatigue lives of various flip chip assemblies The model correlates the amount of creep strain energy dissipated per thermal cycle with the characteristic Weibull life of the critical flip chip solder joint The model has been validated for various die sizes, bump geometries, board materials and thermal profiles Furthermore, the model has accurately predicted fatigue life for flip chip assemblies with and without underfill The solder fatigue model has been previously employed to study the effect of design parameters on the reliability of flip chip on ceramic assemblies subjected to thermal cycling (ie, Part I) In particular, the parametric study showed the effect of die size, die thickness, solder joint geometry and underfill properties on predicted solder fatigue lives A similar study has now been performed for flip chips assembled to organic printed circuit boards (Part II) This study investigates the parameters listed above, as well as specific solder joint parameters such as conductor thickness, total stand-off and net solder joint height (stand-off minus conductor thickness) A comparison of fatigue lives for ceramic and organic assembled flip chips is also made Results show that the coefficient of thermal expansion of the underfill is the most significant parameter affecting fatigue life, with no significant difference seen between fatigue lives of underfilled ceramic and organic assembled devices The effect of solder joint geometry is shown to be solely dependent on the ratio of net solder joint height to chip stand-off

65 citations

Journal ArticleDOI
Pradeep Lall1, M.N. Islam1, John L. Evans1, Jeffrey C. Suhling1, T. Shete1 
TL;DR: In this paper, the effect of metal-backed boards on the interconnect reliability has been evaluated and three adhesives have been investigated for metal backing including arlon, pressure sensitive adhesive, and pre-preg.
Abstract: Increased use of sensors and controls in automotive applications has resulted in significant emphasis on the deployment of electronics directly mounted on the engine and transmission. Increased shock, vibration, and higher temperatures necessitate the fundamental understanding of damage mechanisms which will be active in these environments. Electronics typical of office benign environments use FR-4 printed circuit boards (PCBs). Automotive applications typically use high glass-transition temperature laminates such as FR4-06 glass/epoxy laminate material (T/sub g/=164.9/spl deg/C). In automotive underhood application environments, metal-backing of PCBs is being targeted for thermal dissipation, mechanical stability, and interconnections reliability. In this study, the effect of metal-backed boards on the interconnect reliability has been evaluated. Previous studies on electronic reliability for automotive environments have addressed the damage mechanics of solder joints in plastic ball-grid arrays (BGAs) on nonmetal backed substrates and ceramic BGAs on nonmetal backed substrates. Other failure mechanisms investigated include delamination of PCB from metal backing. The test vehicle is a metal backed FR4-06 laminate. Metal backings investigated include aluminum and beryllium copper. Three adhesives have been investigated for metal backing including arlon, pressure sensitive adhesive, and pre-preg. The use of conformal coating for reliability improvement has also been investigated. Component architectures tested include plastic BGA devices, C2BGA devices, quad flat no-lead (QFN), and discrete resistors. Reliability of the component architectures has been evaluated for hot air solder level and electroless Ni/Au finishes. Crack propagation and intermetallic thickness data has been acquired as a function of cycle count. Reliability data has been acquired on all these architectures. Material constitutive behavior of arlon and pressure sensitive adhesive has been measured using uni-axial test samples. The measured material constitutive behavior has been incorporated into nonlinear finite element simulations. Predictive models have been developed for the dominant failure mechanisms for all the component architectures tested.

47 citations

Proceedings ArticleDOI
13 Oct 1997
TL;DR: In this article, a model for 63Sn/Pb solder was developed by combining nonlinear finite element modeling with thermal fatigue data of assorted flip chip assemblies, which was validated for various die sizes, bump geometries, board materials and thermal profiles.
Abstract: A solder fatigue model for 63Sn/Pb solder has been developed by combining nonlinear finite element modelling with thermal fatigue data of assorted flip chip assemblies. The model characterizes the creep fatigue phenomena of the solder alloy by correlating the amount of creep strain energy dissipated per thermal cycle with the characteristic Weibull life of the critical solder joint. It has been validated for various die sizes, bump geometries, board materials and thermal profiles. Furthermore, the model has accurately predicted fatigue lives for flip chip assemblies with and without underfill. The solder fatigue model has been utilized to investigate the reliability of flip chip joints subjected to thermal cycling. In particular, a parametric study had been performed which shows how various flip chip design parameters will affect solder joint fatigue. Finite element models have been developed to analyze the effect of die size, die thickness, solder joint height, cap diameter and underfill properties on solder fatigue. For this investigation, all analyses have been carried out for parts on ceramic substrates. The results for underfilled parts show that while die size does not influence solder joint reliability, the effects of underfill CTE are very important. Non-underfilled parts are significantly influenced by die size, cap size and joint height.

44 citations

References
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Book
07 Nov 1980
TL;DR: In this article, the authors present practical guides for Natural Convection and Radiation Cooling for Electronic Components. But they do not consider the effects of thermal stresses in lead wires, Solder Joints and Plated Throughholes.
Abstract: Evaluating the Cooling Requirements. Designing the Electronic Chassis. Conduction Cooling for Chassis and Circuit Boards. Mounting and Cooling Techniques for Electronic Components. Practical Guides for Natural Convection and Radiation Cooling. Forced--Air Cooling for Electronics. Thermal Stresses in Lead Wires, Solder Joints, and Plated Throughholes. Predicting the Fatigue Life in Thermal Cycling and Vibration Environment. Transient Cooling for Electronic Systems. Special Applications for Tough Cooling Jobs. Effective Cooling for Large Racks and Cabinets. Finite Element Methods for Mathematical Modeling. Environmental Stress Screening Techniques. References. Index.

185 citations

Journal ArticleDOI
TL;DR: In this paper, an analytical framework to predict failure of solders under creep conditions is proposed, based on both micromechanics and fracture mechanics, and the general agreement between the model predictions and reported creep-rupture data in the literature for lead/tin eutectic solder indicates that the mode and mechanisms proposed in the model may control the solder creeprupture process.
Abstract: An analytical framework to predict failure of solders under creep conditions is proposed. A creep-rupture model for two-phase eutectic solders, based on both micromechanics and fracture mechanics, has been developed. The general agreement between the model predictions and reported creep-rupture data in the literature for lead/tin eutectic solder indicates that the mode and mechanisms proposed in the model may control the solder creep-rupture process. >

100 citations

Book ChapterDOI
TL;DR: In this paper, a 16-I/O surface-mounted solder joint array undergoing isothermal cyclic fatigue in torsion shear under fixed plastic strain range showed a strong correlation with creep fatigue and a creepcracking mechanism.
Abstract: Lifetime studies of a 16 I/O surface-mounted solder joint array undergoing isothermal cyclic fatigue in torsion shear under fixed plastic strain range show a strong correlation with creep fatigue and a creep-cracking mechanism. Experimental lifetime data follow an inverse dependence on matrix creep. Experimental measurement of the steady-state shear creep rate versus shear stress defines the creep characteristic that is sensitive to changes in metallurgical structure. The amounts of grain boundary and matrix creep taking place during a fatigue cycle are derived from experimental creep data combined with stress-strain hysteresis data obtained in steady-state cycling. Initially, thicker solder joints have a larger grain size than thinner solder joints, giving more matrix creep during fatigue and a faster failure rate. Fatigue increases the mean grain size of the solder joint as determined by the creep-rate-versus-stress characteristic and microstructure. Effects of grain size and joint thickness on lifetime are discussed. A maximum in the creep fatigue rate occurs at 333 K (60°C).

78 citations

Journal ArticleDOI
Ahmer R. Syed1
TL;DR: In this paper, a model is developed which predicts the creep damage accumulation in solder joints during temperature cycling, and the model relates the crack growth rate to the rate of creep energy density dissipated using the C* parameter of nonlinear fracture mechanics for extensive creep damage.
Abstract: A model is developed which predicts the creep damage accumulation in solder joints during temperature cycling. The model relates the crack growth rate to the rate of creep energy density dissipated using the C* parameter of nonlinear fracture mechanics for extensive creep damage. For a eutectic tin-lead solder joint, the damage due to both grain boundary sliding and matrix creep is considered. The validity of the model is proved by correlating the predicted fatigue life of solder joints for 84 I/O leadless ceramic chip carriers with the published measured data for a number of test conditions. The published experimental conditions are simulated in a three dimensional, nonlinear, time and temperature dependent finite element analysis. For each test condition, both components of creep energy density, i.e., energy densities because of grain boundary sliding and matrix creep, are determined separately in the finite element analysis. The values are then used to determine the crack growth parameters and predict the crack growth rate in the solder joint using the crack growth model. The predicted results are found to have good correlation with the measured fatigue life for each test condition.

44 citations