Effect of high-frequency PCB laminate on thermal cycling behavior of electronic packaging structures

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lijuan Huang ◽  
Zhenghu Zhu ◽  
Hiarui Wu ◽  
Xu Long
Keyword(s):  
Fatigue Life ◽  
Thermal Cycling ◽  
Electronic Packaging ◽  
High Frequency ◽  
Solder Joints ◽  
Fatigue Cracks ◽  
Cyclic Stress ◽  
Content Type ◽  
Stress States ◽  
Packaging Structure

PurposeAs the solution to improve fatigue life and mechanical reliability of packaging structure, the material selection in PCB stack-up and partitioning design on PCB to eliminate the electromagnetic interference by keeping all circuit functions separate are suggested to be optimized from the mechanical stress point of view.Design/methodology/approachThe present paper investigated the effect of RO4350B and RT5880 printed circuit board (PCB) laminates on fatigue life of the QFN (quad flat no-lead) packaging structure for high-frequency applications. During accelerated thermal cycling between −50 °C and 100 °C, the mismatched coefficients of thermal expansion (CTE) between packaging and PCB materials, initial PCB warping deformation and locally concentrated stress states significantly affected the fatigue life of the packaging structure. The intermetallics layer and mechanical strength of solder joints were examined to ensure the satisfactorily soldering quality prior to the thermal cycling process. The failure mechanism was investigated by the metallographic observations using a scanning electron microscope.FindingsTypical fatigue behavior was revealed by grain coarsening due to cyclic stress, while at critical locations of packaging structures, the crack propagations were confirmed to be accompanied with coarsened grains by dye penetration tests. It is confirmed that the cyclic stress induced fatigue deformation is dominant in the deformation history of both PCB laminates. Due to the greater CTE differences in the RT5880 PCB laminate with those of the packaging materials, the thermally induced strains among different layered materials were more mismatched and led to the initiation and propagation of fatigue cracks in solder joints subjected to more severe stress states.Originality/valueIn addition to the electrical insulation and thermal dissipation, electronic packaging structures play a key role in mechanical connections between IC chips and PCB.

Thermal performance and fatigue life prediction of POP stacked chip assembly under thermal cycling load

2020 ◽  
Vol 37 (4) ◽  
pp. 165-171
Author(s):  
Dongbo Li ◽  
Jianpei Wang ◽  
Bing Yang ◽  
Yongle Hu ◽  
Ping Yang
Keyword(s):  
Fatigue Life ◽  
Thermal Cycling ◽  
Life Prediction ◽  
Solder Joints ◽  
Fatigue Life Prediction ◽  
Load Spectrum ◽  
Thermal Reliability ◽  
Joint Stress ◽  
Content Type ◽  
Fatigue Characteristics

Purpose This paper aims to perform experimental test on fatigue characteristics of package on package (POP) stacked chip assembly under thermal cycling load. Some suggestions for design to prolong fatigue life of POP stacked chip assembly are provided. Design/methodology/approach The POP stacked chip assembly which contains different package structure mode and chip position was manufactured. The fatigue characteristics of POP stacked chip assembly under thermal cycling load were tested. The fatigue load spectrum of POP stacked chip assembly under thermal cycling load was given. The fatigue life of chips can be estimated by using the creep–fatigue life prediction model based on different stress conditions. Findings The solder joint stress of top package is significantly less than that of bottom solder joints, and the maximum value occurs in the middle part of the solder joints inner ring. Originality/value This paper fulfils useful information about the thermal reliability of POP stacked chip assembly with different structure characteristics and materials parameters.

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.

Reliability of Underfill-Encapsulated Flip-Chips With Heat Spreaders

1998 ◽  
Vol 120 (4) ◽  
pp. 322-327 ◽  
Author(s):  
H. Doi ◽  
K. Kawano ◽  
A. Yasukawa ◽  
T. Sato
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Thermal Cycling ◽  
Failure Mode ◽  
Flip Chip ◽  
Solder Joints ◽  
Alumina Substrate ◽  
Heat Spreader ◽  
Flip Chips ◽  
Heat Spreaders

The effect of a heat spreader on the life of the solder joints for underfill-encapsulated, flip-chip packages is investigated through stress analyses and thermal cycling tests. An underfill with suitable mechanical properties is found to be able to prolong the fatigue life of the solder joints even in a package with a heat spreader and an alumina substrate. The delamination of the underfill from the chip is revealed as another critical failure mode for which the shape of the underfill fillet has a large effect.

Morphology transformation on Cu3Sn grains during the formation of full Cu3Sn solder joints in electronic packaging

2018 ◽  
Vol 30 (1) ◽  
pp. 14-25 ◽  
Author(s):  
Peng Yao ◽  
Xiaoyan Li ◽  
Fengyang Jin ◽  
Yang Li
Keyword(s):  
Electronic Packaging ◽  
Design Methodology ◽  
Solder Joints ◽  
Critical Size ◽  
Content Type ◽  
Detailed Mechanism ◽  
Ripening Process ◽  
Research Gap ◽  
Equivalent Method ◽  
First Time

Purpose This paper aims to analyze the morphology transformation on the Cu3Sn grains during the formation of full Cu3Sn solder joints in electronic packaging. Design/methodology/approach Because of the infeasibility of analyzing the morphology transformation intuitively, a novel equivalent method is used. The morphology transformation on the Cu3Sn grains, during the formation of full Cu3Sn solder joints, is regarded as equivalent to the morphology transformation on the Cu3Sn grains derived from the Cu/Sn structures with different Sn thickness. Findings During soldering, the Cu3Sn grains first grew in the fine equiaxial shape in a ripening process until the critical size. Under the critical size, the Cu3Sn grains were changed from the equiaxial shape to the columnar shape. Moreover, the columnar Cu3Sn grains could be divided into different clusters with different growth directions. With the proceeding of soldering, the columnar Cu3Sn grains continued to grow in a feather of the width growing at a greater extent than the length. With the growth of the columnar Cu3Sn grains, adjacent Cu3Sn grains, within each cluster, merged with each other. Next, the merged columnar Cu3Sn grains, within each cluster, continued to merge with each other. Finally, the columnar Cu3Sn grains, within each cluster, merged into one coarse columnar Cu3Sn grain with the formation of full Cu3Sn solder joints. The detailed mechanism, for the very interesting morphology transformation, has been proposed. Originality/value Few researchers focused on the morphology transformation of interfacial phases during the formation of full intermetallic compounds joints. To bridge the research gap, the morphology transformation on the Cu3Sn grains during the formation of full Cu3Sn solder joints has been studied for the first time.

Critical Accumulated Strain Energy (Case) Failure Criterion for Thermal Cycling Fatigue of Solder Joints

1994 ◽  
Vol 116 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Tsung-Yu Pan
Keyword(s):  
Fatigue Life ◽  
Energy Density ◽  
Thermal Cycling ◽  
Creep Strain ◽  
Failure Criterion ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Solder Joints ◽  
Field Service ◽  
Accumulated Strain

In the automotive and computer industries, a perennial challenge has been to design an adequate and efficient accelerated thermal cycling test which would correspond to field service conditions. Failures, induced in both thermal cycle testing and field service, are characterized by thermal fatigue behavior. Several fatigue models have been proposed, none of these models take into account all of the many parameters of the test or service environment. In thermal cycling, for example, the temperature range, ramp rate, hold time, and stepped heating and cooling are known to influence the number of cycles to failure. In this study, a critical accumulated strain energy (CASE) failure criterion is proposed to correlate the fatigue life to both the plastic and creep strain energies, which accumulate in solder joints during the thermal cycling. This criterion suggests that solder joints fail as the strain energy accumulates and reaches a critical value. By using finite element analysis with a “ladder” procedure, both time-independent plastic strain energy and time-dependent creep strain energy are quantified. These are related to fatigue life by the equation: C = N*f (Ep + 0.13Ec), where C is the critical strain energy density, Nf is the fatigue life, Ep and Ec are plastic and creep strain energy density accumulation per cycle, respectively, for the eutectic Sn-Pb solders. By analyzing Hall and Sherry’s thermal cycling data (Hall and Sherry, 1986), it is found that creep is the predominant factor in deciding fatigue life. Creep accounts for 51 to 97 percent of the total accumulated strain energy, depending on the cycling profiles. This criterion is used to simulate crack propagation in a solder joint by analyzing the strain energy in small “domains” within the joint.

The Behavior of Salem Limestone in Cyclic Loading

1974 ◽  
Vol 14 (01) ◽  
pp. 19-24 ◽  
Author(s):  
S.S. Peng ◽  
E.R. Podnieks ◽  
P.J. Cain
Keyword(s):  
Fatigue Life ◽  
Cyclic Loading ◽  
Material Properties ◽  
High Frequency ◽  
Low Frequency ◽  
Tensile Loading ◽  
Cyclic Stress ◽  
Time Dependent ◽  
Mean Stress ◽  
Frequency Range

Abstract Specimens of Salem limestone were loaded cyclically at a frequency of 2 cycles/sec in uniaxial cyclic compression, tension, and compression-tension. The number of cycles to failure, maximum deformation for each cycle, and load-deformation hysteresis loops were recorded. The fatigue life and fatigue limit values under cyclic compressive loading are comparable with those under cyclic tensile loading, whereas under cyclic compressive-tensile loading they are considerably lower. Introduction The study of rock behavior in cyclic loading has been relatively ignored in the past, even though certain problems in rock mechanics are closely related to cyclic loading. These problems include the effects of percussive drilling and the vibrations generated by blasting. An understanding of the mechanisms of fatigue failure in rock can be expected to help improve drilling efficiency and prevent vibration damage caused by blasting. Because of the lack of bask information on rock behavior under cyclic loading, the Federal Bureau of Mines, Twin Cities Mining Research Center began in 1968 an extensive program for studying cyclic loading effects. This program included the investigation of the behavior of rock loaded cyclically at different frequencies under varying test geometries, loading configurations, and environments. In the high-frequency range, sonic power transducers are being used to apply cyclic loading at a frequency of 10,000 Hz, and an electromagnetic shaker is being used at frequencies from 100 to 1,000 Hz. In the low-frequency range, cyclic loading of 2 to 10 Hz is applied by a closed-loop servocontrolled electrohydraulic testing machine. In each frequency range, experiments are conducted to provide the following information: fatigue limits, fatigue life, energy dissipation, temperature induced in the specimen, and the time history of load and deformation. This paper presents the first phase of be results obtained on specimens of Salem limestone loaded in the low-frequency range. The early findings on the high-frequency effects were reported separately. Recently, the effect of cyclic loading on rock behavior has been receiving more attention and considerable information is being generated. General Loading Concept in Cyclic Loading In conventional strength tests the monotonic loading program is specified by the loading rate and control mode. For cyclic loading, where the load is a periodic function of time, the problem is more complex. To evaluate such material properties as fatigue life, the load must be described systematically and concisely in terms of physically significant parameters. parameters. For a general case, one approach is to divide the cyclic stress into time-independent and time-dependent components. The time-independent component (or mean stress) is the time average of the stress. A cyclic stress with an amplitude A and zero mean can be superimposed on this loading. For the usual case of cyclic loading with steady loading conditions, the stress can be described as follows.(1)= + (t), where f(t) is a periodic function of time, t, and can be represented by a sine or sawtooth wave. Other ways of describing the stress are available such as using the maximum and minimum stresses, which are related to the mean and amplitude:(2)max = . and(3)min = . The key issue is to describe the loading in terms that will correlate with the material properties of interest. The use of amplitude and mean stress to describe cyclic loading separates the time-dependent bona the time-independent portion of the stress because the effect of each portion of the loading should be investigated separately. In analyzing the effect of cyclic loading on rock, another significant factor is the large difference between the tensile strength and the compressive strength. P. 19

Extending the fatigue life of Pb-free SAC solder joints under thermal cycling

2013 ◽  
Vol 53 (5) ◽  
pp. 741-747 ◽  
Author(s):  
Shoho Ishikawa ◽  
Hironori Tohmyoh ◽  
Satoshi Watanabe ◽  
Tomonori Nishimura ◽  
Yoshikatsu Nakano
Keyword(s):  
Fatigue Life ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Sac Solder

The Creep-Fatigue Interaction in Solders and Solder Joints

1990 ◽  
Vol 112 (2) ◽  
pp. 100-103 ◽  
Author(s):  
D. S. Stone
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Solder Joints ◽  
Fatigue Cracks ◽  
Solution Concentration ◽  
Grain Boundary Sliding ◽  
Cycle Frequency ◽  
Low Frequencies ◽  
Creep Fatigue ◽  
Failure Life

Two models are proposed for relating the metallurgy of the solder to the growth of fatigue cracks through solder joints. These models illustrate how different aspects of the creep behavior can contribute to the so-called “creep-fatigue interaction”. The first model treats fatigue crack growth through the solder, far from the interface between solder and substrate. Either an intragranular or intergranular path may be taken depending upon conditions of loading. Intragranular fatigue dominates when the cycle frequency is high, in which case failure life is governed by the Coffin-Manson law. Intergranular failure occurs at low frequencies because grain boundary sliding at low frequencies allows the grain boundaries to become exposed to the atmosphere, which in turn causes oxidation. This model predicts the effects of frequency, strain amplitude, and grain size on fatigue life. In the second model, the fatigue crack travels within the interface region between solder and substrate. Here, the strain introduced in the solder joint during fatigue is not relevant; instead, the stress transferred to the interface is more important. The second model considers the effect of solid solution concentration on fatigue life. The predictions of both models agree reasonably well with published fatigue data from solders and solder joints.

Experimental Damage Mechanics of Microelectronic Solder Joints Under Fatigue Loading

2002 ◽  
Author(s):  
Cemal Basaran ◽  
Hong Tang ◽  
Shihua Nie
Keyword(s):  
Elastic Modulus ◽  
Fatigue Life ◽  
Thermal Cycling ◽  
Fatigue Damage ◽  
Solder Joints ◽  
Fatigue Loading ◽  
Damage Mechanism ◽  
Load Drop ◽  
Material Degradation ◽  
Elastic Modulus Degradation

Fatigue damage is a progressive process of material degradation. The objective of this study is to experimentally qualify the damage mechanism in solder joints in electronic packaging under thermal fatigue loading. Another objective of this paper is to show that damage mechanism under thermal cycling and mechanical cycling is very different. Elastic modulus degradation under thermal cycling, which is considered as a physically detectable quantity of material degradation, was measured by Nano-indenter. It was compared with tendency of inelastic strain accumulation of solder joints in Ball Grid Array (BGA) package under thermal cycling, which was measured by Moire´ interferometry. Fatigue damage evolution in solder joints with traditional load-drop criterion was also investigated by shear-strain hysteresis loops from strain-controlled cyclic shear testing of thin layer solder joints. Load-drop behavior was compared with elastic modulus degradation of solder joints under thermal cycling. Following conventional Coffin-Manson approach, S-N curve was obtained from isothermal fatigue testing with load-drop criterion. Coffin-Manson curves obtained from strain controlled mechanical tests were used to predict fatigue life of solder joints. In this paper it is shown that this approach underestimates the fatigue life by an order of magnitude. Results obtained in this project indicate that thermal fatigue and isothermal mechanical fatigue are completely different damage mechanism for microstructurally evolving materials.

scholarly journals Experimental Study on the Reliability of PBGA Electronic Packaging under Shock Loading

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 279 ◽  
Author(s):  
Jiang Shao ◽  
Hongjian Zhang ◽  
Bo Chen
Keyword(s):  
Fatigue Life ◽  
Electronic Packaging ◽  
Failure Modes ◽  
Solder Joints ◽  
Optical Microscope ◽  
Micro Cracks ◽  
Plastic Ball ◽  
Plastic Ball Grid Array ◽  
Aeronautical Industry ◽  
The Relationship

Plastic Ball Grid Array (PBGA) one of the most important electronic packaging methods, is widely used in aeronautical industry field. According to the JEDEC standard, shock tests of PBGA assemblies are conducted under different loading conditions. Several important parameters, such as the fatigue life of PBGA assemblies, the relationship between solder joint positions and fatigue life, the relationship between strain energy density and fatigue life, are analyzed based on experiment results. The failure modes of PBGA assemblies are studied by optical microscope (OM). The results show that during the shock tests, the strains of the solder joints near the center of the specimen are larger than other positions, and these solder joints are prone to form micro cracks. With the increase of the shock times, these micro cracks extend rapidly which will eventually cause the failure of the PBGA electronic packaging.

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