This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
Reliability Assessment of Solder Joints in Electronic Devices under
Extreme Thermal Fluctuations
A. Surendar1*, M. Kavitha2, M. Arun3, V. Panwar4
1
Research Scholar, Anna University, India
R&D Head, Advanced Scientific research, India
3
School of Electronics Engineering (SENSE), VIT University, Vellore, India
4
Research Scholar, VTU - RRC, Belagavi, Karnataka, India
*
Corresponding Author, Email: asurendar688@gmail.com
2
However, they have also suffered from external loads. The
previous investigations accurately analyzed and simulated the
fundamentals of damage evolution under the operation. However,
all these studies focused on the civil electronic products usually
worked in a certain temperature range. On the other side, with the
accelerated growth of aerospace industry it is critical to evaluate
the reliability of electronic systems when they are exposed to the
specific cryogenic environment. The travelling of on-orbit
satellites, including manifold electronic systems, into the deep
space may lead to the thermal shocks to all the components [11].
Hence, it is required to evaluate the thermo-mechanical fatigue
life of electronic structures using mechanics-based acceleration
methods [12]. Under this condition, the increase in thermal
cycling frequency, the rise in upper-bound temperature of thermal
cycle and mechanics-based acceleration for mechanical failure of
solder interconnections are the main aspects leading to an
accelerated process. In the meanwhile, it is also suggested that the
induced-stress during the shocking thermal situations may be
similar to the mechanics-based loading condition accelerating the
mechanical degradation of solder interconnections with more
controllable deformation [12]. There are few works evaluating the
vulnerability of Sn-based solder joints under thermal shocks. For
instance, Vries et al [13] showed that the extreme temperature
gradient in the thermal shock loading significantly declines the
reliability of solder ball grid arrays. With a proper design of
simulation parameters, they found a meaningful relation between
costume thermal cycling and thermal shock events. Lupinacci et
al [14] the solder ductility of electronic packages used in the
aerospace industry. It was revealed that the Sn-based solder joints
experienced a ductile to brittle transition at very low temperatures
causing catastrophic crack propagation and accelerated damage
in electronic components of spacecraft payloads. In a series of
works done by Tian et al [15]–[17], it was figured out that with
the enhancement of cryogenic storage time, the thickness of
intermetallic compounds gradually rises in the solder joints.
Wang et al [11] performed extreme thermal shocking test from 77
Abstract - In this work, the effects of extreme thermal
fluctuations on the reliability of solder joints were investigated. For
this purpose, the solder joints in IGBT devices were exposed to the
conventional thermal cycling and the thermal shock cycling tests.
The FEM simulation results indicated that the accumulated creep
energy in solder layer is much higher under the thermal shock
cycling process. Moreover, the stress triaxiality, as the indicator of
damage initiation, is more concentrated in the thermal shock cycling
exposed sample. It is believed that the higher heating and cooling
rates along with the higher peak temperatures lead to the damage
susceptibility of solder joints under thermal shock cycling process.
The experimental results confirm that the void formation and
growth significantly increases in the thermal shock cycling exposed
sample which is consistent with the simulation outcomes. Moreover,
the shear test reveals that the ultimate strength of sample under the
thermal shocking severely decreases which is due to the void growth
and the intensified elemental heterogeneity.
Keywords, Thermal Shock, Reliability, Microstructure, FEM
Simulation, Fatigue.
1-
Introduction
The rapid growth of power semiconductor devices has been
one of the main challenges of researchers to improve the
efficiency of electronic systems [1], [2]. With a complex
structure, these devices include several components assembled
with each other using a specific solder process [3]. In the past
decades, numerous works have been done showing the severe
vulnerability of solder joints when external loadings are applied
to the electronic systems [4], [5]. The thermal and power cycling
loads along with the random vibration are the examples of
destructive sources causing failure in the solder interconnections
[6], [7]. Fabrication of electronic components may enhance by
using recent novel materials such as sintered silver particles [8],
[9]. Integrated sintered silver nanoparticles with SiC
microparticles are one of the most recent and promising
packaging materials for high power semiconductors [10].
1
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
to 423 K and reported that the thermal shocking leads to the
significant growth of Cu6Sn5 intermetallic compounds and also
changes the shape of intermetallic growth from columnar to plane
shape. It was shown that the growth of this intermetallic was
considerably affect the thermomechanical behavior of solder
joint. No consideration process induced voids as well as triaxiality
factor in the lifetime estimation of this solder joint were the two
main gaps which are stilling lacking in the recent studies.
As aforementioned, the concentration of studies on cryogenic
thermal shocks was on the materials characterization and its
relation to the mechanical properties. In the mentioned works,
many realistic parameters in the damage evolution of solder joints
were ignored and consequently it is yet required to evaluate the
solder joint reliability under the extreme thermal situations and
the harsh environments. The primary embedded voids in the
solder joint were one the main factors affecting the solder
reliability under the thermal cycling [18], [19]. However, there is
no work to show their catastrophic effects under the thermal
shock loadings. In our work, we experimentally and theoretically
aim to indicate that how these voids accelerate the failure
evolution in the solder joints of electronic systems exposed to the
extreme thermal cycling.
2-
Fig. 1. Power component. a) Physical structure, b) FEM meshed model.
performance of IGBT module, especially solder joint, under
conventional and shock thermal cycling, several FEM simulations
were fulfilled in ABAQUS environment under coupled
temperature-displacement modeling step analysis in the transient
mode. A FEM model was totally including 14384 and 28326
elements and nodes, respectively. ABAQUS mesh optimization
tool was also used for optimizing the result accuracy and
simulation time. Since solder joints were extensively reported as
the weakest part in the power devices owing two induced electro
thermomechanical stresses [21], [22], solder joints are the center
of interest of this study. Therefore, the solder joint has to be
analyzed under different thermal cycling loads as the main root
cause of thermomechanical failure in the solder joint. The
characteristics of the considered solder joint is listed in Table. 1.
As shown in Table 1, a large CTE mismatch among the diverse
parts in the IGBT module sparked off creep phenomena as one of
the most critical thermo mechanical failure mechanism in the
solder joint. Thus, the process of creep failure in common was
within the active play to fiercely determine the damage evolution
of ball solder joint. There are several constitutive models for
explaining the viscoplastic (creep) behavior of the solder joints,
like Anand and Garofalo-Arrhenius [23]–[26]. Both specific
models typically share the same fate in solder material for
determining creep strain. Because of its inclusion in the
ABAQUS package, it was preferred to adopt Garofalo-Arrhenius
model in this study [27]. A hyperbolic sine model is presented in
this equation to express the creep behavior in the solder joints.
The steady state creep strain rate is defined as follows:
FEM Simulation
In this study a power IGBT was under study. Fig. 1
demonstrates its structure and FEM model in ABAQUS package.
It consists of various layer including Cu clip, front solder, chip,
back solder and Cu baseplate. Global length and width of IGBT
module are limited to 12mm and 6.3mm, respectively. Main
layers from bottom to top are Cu baseplate, back solder joint,
power chip, front solder joint and Cu clip, respectively. Solder
joint thickness is considered 40um. It worth mentioning that
signal bond wires were neglected due to the simplicity without
losing accuracy. One can find that diverse materials with different
coefficients of thermal expansion (CTEs) are joined via soldering
which ignite thermomechanical stresses through the bodies
especially in solder joint as the weakest part of power IGBT [20].
Thermal, electrical and mechanical connections are all achieved
via soldering. A common lead-free solder, namely 95.5Sn-3.8Ag0.7Cu, was employed in this study. For scrutinizing the
 cr  C1  sinh  C2   exp  C4 T 
C3
(1)
Table. 1. Material properties of different sections in the IGBT module
Young Module
CTE
Poisson’s
Density
Thermal Conductivity
Sections
(GPa)
(10-6/oC)
Ratio
(*10-6kg/mm3)
(w/mK)
20
43
95.5Sn-3.8Ag-0.7Cu 100
36
23.2
0.30
7.37
all
57
200
22
20
131
20oC
168
Si Chip
100
128.7
3.5
0.22
2.33
100oC
112
200
127.3
200oC
82
20
129
20oC
401
Cu pad
100
127.9
17
0.34
8.69
100oC
391
200
126.3
200oC
389
2
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
έcr is the creep strain rate and C1, C2, C3 and C4 are constant
values for SAC solder [25], [28], [29]. σ is the applied stresses
induced by temperature variations (thermal cycling). The constant
values were considered as 2.73*105 (1/s), 0.023 (MPa)-1, 6.3 and
6480.3 for C1, C2, C3 and C4, respectively.
thermal cycling. In order to evaluate the mechanical properties of
solder joints, a micro-tensile test equipment was employed to
measure the shear strength of interconnections. The cross-head
speed of 0.25 mm/min was considered for the shear test. To have
a standard sample for shear test, the package was ground
somehow to produce a cube with the dimension of 0.5 cm. Under
this condition, the solder layer have to be located at the center of
final cubic sample. The cubic specimen was then located in a
fixture with two separated parts. The tensile test machine applies
the force in the direction of solder layer and the fixture interface
(see Fig. 3).
One of the crucial problems for solder joint fatigue is
unavoidable existence of voids, which in general determines the
reliability of the IGBT module. The voids may be divided into
three separate categories: i) Kirkendall voids, ii) nucleated small
voids under thermal cycling fatigue and iii) large process induced
voids which are created during manufacturing [30]. The presence
of process induced voids comes from the outgassing of stored flux
during the reflow cycle. Employing tomography images, Chan et
al. [31] reveals that the volume of these voids will be a huge
portion the total volume of the solder joint. Since, the process
induced voids in the solder joint are the main factors affecting the
solder reliability under the thermal cycling [18], [19], several
random voids were considered in the FEM simulations. Monte
Carlo Representative Volume Element Generator method is used
to create the distribution of the voids within the solder sheet. In
order to attain the accurate results in FEM simulation, pre-voids
were employed in the solder layer under a random distribution.
Based on the literature [32], the volume fraction of voids were
considered 25% so that they were kept in the solder layer in a
blind mode, which leads to the preparation of real situations for
the simulation. It should be noted that the spherical and oval
shapes of micro-voids will show that how the induced stress will
generate in the solder layer. It is also worth-mentioning that the
size and shapes of designed micro-voids were extracted from the
previous works [32]. Regarding thermal load specifications, the
FEM simulations categorized into two different parts, namely for
conventional thermal cycling (CTC) and thermal shock cycling
(TSC) loading. Thermal cycling loads are shown in Fig. 2. Based
on this figure two different thermal loads with the same dwelling
time were investigated. Both thermal cycles had the same cold
and hot dwelling time (60 min). In TSC the cold temperature
reached -170oC while in CTC the minimum temperature was
limited to -40oC. Heating and cooling ramp rates were similar to
each other in CTC thermal load and were +/- 3.5oC/min. While,
heating and cooling rates were sudden in the TSC case.
3-
4-
Results and Discussion
The characterization of solder degradation in the solder joint
strongly depends on the understanding of strain energy evolution
in the assembly. Hence, the first step to predict the fatigue life
time of solder interconnections is to evaluate the accumulated
creep strain in the joint zone. Fig. 4 shows the distribution of
accumulated creep strain energy across the layer of solder joint
when the system was exposed to CTC and TSC. The previous
studies, done by many researchers, indicated that the accumulated
energy concentration is mostly located at the edges of solder layer
so that it is easily estimated that the crack initiation and
propagation would be happened at the corner sides of solder joint
[18], [33]. At first glance, Fig. 4 indicates that the accumulated
energy distribution is significantly different when the pre voids
come into play. The detailed layer-by-layer image of solder joints
showed that the voids faze the energy distribution along the solder
thickness. Moreover, one can see that mean value of strain energy
is higher at the proximity of surface, where the solder sticks to the
Si chip. However the mean strain energy value decreases towards
the depth of solder layer. It is believed the considerable
distinction between the CTE of the Si chip and solder leads to the
creation of higher strain energy at the interface of solder. It is also
Experimental Procedure
In order to application of CTC and TSC processes, a furnace
setup with the potential of temperature changing from -180 0C up
to 300 0C was employed. The cryogenic temperature in the setup
was attained using a liquid nitrogen cryogenic system. The
thermal cycling procedure, including CTC and TSC processes,
was similar to the FEM simulation input. Three samples for each
situation were tested to obtain reliable experimental results. After
thermal cycling, the samples were perpendicularly sectioned and
polished for subsequent observations. Scanning electron
microscopy (SEM) along with the energy dispersive spectroscopy
(EDS) was used to study the microstructure of joint zone after
Fig. 2. Thermal cycling loads in different conditions.
Fig. 3: schematic of shear test fixture.
3
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
Fig. 4: distribution of accumulated creep strain energy in the solder joints layered-by- layered under a) CTC, b) TSC.
Fig. 5: layer-by-layer hydrostatic stress distribution along the solder joint exposed to the TSC process. a) Maximum and b) minimum temperatures.
worth-mentioning that the boundaries of voids are potential sites
for energy intensification in the solder layer. Furthermore it is
observed that the intensification of accumulated strain energy
increases at the sites where the voids density rises. It is suggested
that the higher density of voids in a certain bulk of solder leads
to the trapping of strain energy and the creation of highly
affected region in the interconnection. The mentioned events are
general for both solder samples exposed to the CTC and TSC.
However, the accurate evaluation of energy distribution in the
same place of solder joints showed that strain energy generation
of TSC sample is 1.6 times higher than the CTC sample. This
result clearly determines that the TSC process is a critical event
decreasing the reliability of solder joints in IGBTs. One of the
main reasons is associated with the higher strain rate induced by
the TSC process. In fact, under the extreme situations the solder
interconnection experiences sharper strain rates [34]. Although,
the coupled effects of creep and fatigue lead to the solder
deterioration, the dominant mechanism strongly relies on the
parameters like the strain rate. With higher strain rates at the
TSC process, the sharp cyclic event, which mainly correlated to
the stress changes, is the bolder failure mechanism so that the
major stored energy in the solder layer may be led by the higher
strain rate. While, the CTC process provides lower strain rate
leading to a slight stress relaxation in the solder joint under the
thermal cycling. Hence, this event causes a lower stored energy
under the CTC process.
To further analysis, the stress characteristics in the solder layer
should be evaluated. Fig. 5 shows the layer-by-layer hydrostatic
stress distribution along the solder joint exposed to the TSC. It
is seen that the hydrostatic stress includes two negative and
4
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
Table 1. EDS analysis of zones in solder joints (wt. %)
Zones
Tin
Copper
Silver
Others
1
2
3
4
5
6
82.1
69.4
81.1
66.2
72.8
60.3
17.6
30.6
18.4
33.1
26.3
39.4
0.1
0.2
0.3
0.5
0.7
0.1
0.2
0.2
0.2
0.2
0.2
0.2
The magnified image of embedded voids is given in Fig. 7. It
can be seen that the void boundaries are source of triaxial
stresses in the solder joint, however the void shape alters the
triaxiality intensification. The voids with oval configuration are
more sensitive to the triaxiality, while the sphere-shape ones
faces lower triaxial stresses. This event mostly depends on the
void shape, where the oval void with the sharper boundaries,
especially at their apex, induces more triaxiality in the solder
material compared with the other ones.
Fig. 8 shows the correlation between the TSC process and the
mean triaxiality at the critical regions of solder interconnection.
In general, the material is exposed to the accelerated degradation
when the TF is more than 1 [18]. Considering this fact, the solder
joint is susceptible to the damage evolution at the temperatures
higher than 50oC, when the tension mode is dominant in the joint
zone. It is also concluded that the tension mode includes the high
peak temperature along with the critical parts of cooling and
heating stages near the high peak temperature. This result
indicates that the CTE mismatch between components at the
higher temperature shows its crucial effects on the degradation
of solder joints. On the other side, the creep event comes into
play at high peak temperature and facilitates the viscoplastic
flow and subsequent void growth and coalescence in the material
resulting in the accelerated damage evolution at the interface.
The Fig.8 also shows that the shear mode (0<TF<1) is adapted
with the huge part of heating and cooling stages during a single
cycle. The shear mode is not as catastrophic as the tension mode;
however it can be responsible for the void growth and their
reorientation [18]. Nevertheless, it should be noticed that the
cooling and heating stage rates are very sharp in the TSC and
consequently one cycle does not responsible for the mentioned
events. The void growth and coalescence, the viscoplastic flow
and the defect reorientations appear in the system when the
significant number of thermal cycles was exposed.
Fig. 6: hydrostatic stress at the edges of solder layers under a) CTC and b)
TSC.
Fig. 7: The appearance of stress triaxiality at the void boundaries.
positive modes defining the compression and tension situations,
respectively. The results reveal that the void boundaries are
critical regions with the high concentrated hydrostatic stress at
both of low and high peak temperatures. It is also detected that
the hydrostatic tension mode at minimum peak temperature 170oC tends to the central part of solder especially where the
voids are arranged close together, while the high peak
temperature leads to the intensification of tension hydrostatic
stress at the edges. This outcome determines that at the heating
stage of TSC process, the severe CTE mismatch between the
IGBT components makes the intensification of tension mode at
the edges, while the stress mode changes to the compression at
the cooling stage [18]. As a whole it is found that the CTE
mismatch between the components along with the void
population and distribution in the solder thickness plays an
impotent role in the hydrostatic stress fluctuations. The
compression mode keeps the solder joint resistant to the failure,
while the tension parts are susceptible to the crack initiation in
the interconnection. With a magnification at the edges of solder
layer, one can see that the intensification of tension mode at the
peak temperature of TSC process is much higher than the CTC
sample (see Fig. 6). This result confirms that how the rate of
heating stage, as the inducer of stresses, affects the value of
tensile hydrostatic components in the interconnection. In other
words, the sharper heating rate in TSC process, intensifies the
influence of CTE mismatch in the assembly and rises the tension
stresses in the solder layer. Hence, the tensile hydrostatic tension
is intensified and consequently the triaxiality event, as a failure
indicator, increases at the edges or in the neighborhood of microvoids. While the lower heating rate in CTC process leads to the
smaller hydrostatic tension and stress triaxiality.
Fig. 8: relation between stress triaxiality and TSC process
5
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
Fig. 9: SEM micrographs of solder joints for a) as-received, b) CTC and c) TSC samples.
As a complementary study, the experimental works were done
to justify the FEM simulation outcomes. Fig. 9 illustrates the
SEM images of solder joints in the IGBTs. As observed, three
main regions can be detected in all the solder joints. The dark
ones introduce the micro voids in the microstructure, while the
bright and grey zones are two metallic phases with different
chemical compositions. According to the EDS results (Table 1),
the grey zones contain a considerable amount of Cu element
while the bright ones are rich in tin. The detailed observation
indicated that the elemental distribution in as-received solder
joint is more uniform than the CTC and TSC samples. In other
words, it is detected that the thermal-exposed samples show a
more heterogeneous microstructure in the joint zones. It is
believed that the frequent thermal cycling of samples provides
driving force for elemental diffusion at the interface and
facilitates the intermetallic formation in the interconnection. The
exposure at the high peak temperature along with the residual
stresses, induced during heating and cooling stages, is
responsible for diffusion of Sn and Cu across the joint zone and
leads to the increase of intermetallic compounds [27]. The
simulation results, in Fig. 4, showed that the creep strain energy
in the TSC sample is much higher than the CTC one.
Considering EDS analysis, one can see that the increase in creep
energy relates to the elemental distribution of elements under
thermal cycling so that the elemental heterogeneity intensified
when the creep energy increased in the solder joint. Hence, it is
suggested that the higher energy accumulated during the TSC
process induces more elemental heterogeneity and intermetallic
formation in the solder layer. The void concentration is another
point should be mentioned. The detailed image analyzing of
solder joints were carried out to investigate the void distribution
in the joint zone. Several SEM images were considered for each
situation to obtain a reliable result. It is measured that the void
concentration in the as-received, CTC and TSC samples is 7, 17
and 26%, respectively. The void percentage for the as-received
sample is due to the soldering process and its inevitable void
formation in the microstructure. However, the meaningful
increase of void percentage after the thermal cycling indicates
that the strain energy also induces void formation and growth in
the microstructure. In general, the void formation and growth is
a fundamental theory of fatigue-creep event describing the
balance of accumulated energy in the material, i.e. the
accumulated strain energy intensifies the migration of vacancies
and their coalescence in the microstructure which leads to the
rise in number of voids and their size. Fig. 10 illustrates the shear
stress-strain curves of the as-received, CTC and TSC solder
joints. The findings show that when the interconnection is
subjected to the TSC cycle the overall strength of the solder joint
dramatically decreases. The high percentage of void coupled
with the extreme elemental heterogeneity encourages crack
forming under shear loading operation. On the other side, the
decrease in population of voids leads to the limitation of defects
propagation in the material. Hence, compared to the TSC joint,
the CTC sample has the higher shear strength indicating the
higher reliability in the interconnection of electronic system. To
accurately investigate the microstructural evolution in the solder
joints, XRD test was done from the surface of fractured solder
joints. Considering Fig. 11, it is found that some intermetallic
compounds are formed in the joint zone which are similar for all
the samples. In general, the solder layer consists of Sn-based
solid solution as a matrix along with some island-shape
intermetallic compounds distributed along the interface.
However, the XRD spectra show that the thermal cycling
changes the intermetallic formation rate in the joint zone. Using
normalized intensity ratio (NIR) method as a peak evaluation
technique in the XRD test [35], one can conclude that the
thermal cycling intensified the intermetallic peaks in XRD
results indicating the excessive formation of intermetallic
compounds at the interface. On the other side, the solid solution
Fig. 10: The shear stress-strain curves of solder joints.
6
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
References
[1]
[2]
[3]
[4]
[5]
[6]
Fig. 11: XRD spectrum of different samples. From top to bottom: As received,
CTC, TSC.
[7]
phase significantly decreases in the interconnection. It is
believed that the thermal cycling provides driving force for
elemental diffusion and microstructural heterogeneity in the
solder layer which subsequently leads to the formation of
intermetallic compounds. Moreover, it is seen that the TSC
process with an extreme cycling procedure causes more thermomechanical effect and subsequent more intermetallic formation
in the joint zone. As a result, the consideration of both FEM
simulation and experimental outcomes indicates the significant
decrease in the reliability of TSC solder joint compared with the
CTC one.
[8]
[9]
[10]
[11]
5- Conclusions
The purpose of this work was to demonstrate how severe
thermal variations reduce the strength of solder joints. The
simulation results revealed that the TSC cycle greatly improved
the energy in the solder joint from the creep pressure. Moreover,
TSC cycle also leads the increased tension triaxiality at the edges
and the void boundaries. On the other hand, the experimental
results showed that the thermal shocking contributed to a
substantial increase in the solder layer of void formation and
production. In addition, the TSC cycle more induces elementary
heterogeneity at interconnection compared with the CTC case.
The mechanical properties of the solder joint then dramatically
weaken such that the overall shear strength for the TSC-exposed
sample falls by more than 40 per cent.
[12]
[13]
[14]
[15]
[16]
M. A. Eleffendi and C. M. Johnson, “In-Service Diagnostics
for Wire-Bond Lift-off and Solder Fatigue of Power
Semiconductor Packages,” IEEE Trans. Power Electron., vol.
32, no. 9, pp. 7187–7198, 2017.
V. Samavatian, H. Iman-Eini, Y. Avenas, and S. Shemehsavar,
“Reciprocal and Self-Aging Effects of Power Components on
Reliability of DC-DC Boost Converter with Coupled and
Decoupled Thermal Structures,” IEEE Trans. Components,
Packag. Manuf. Technol., p. 1, 2019.
S. Roy and F. Khan, “Live condition monitoring of switching
devices using SSTDR embedded PWM sequence: A platform
for intelligent gate-driver architecture,” in 2017 IEEE Energy
Conversion Congress and Exposition (ECCE), 2017, pp.
3502–3507.
V. Samavatian, A. Masoumian, M. Mafi, M. Lakzaei, and D.
Ghaderi, “Influence of Directional Random Vibration on the
Fatigue Life of Solder Joints in a Power Module,” IEEE Trans.
Components, Packag. Manuf. Technol., pp. 1–7, 2018.
L. Wu, X. Han, C. Shao, F. Yao, and W. Yang, “Thermal
Fatigue Modelling and Simulation of Flip Chip Component
Solder Joints under Cyclic Thermal Loading,” Energies , vol.
12, no. 12. 2019.
M. Samavatian, L. K. Ilyashenko, A. Surendar, A. Maseleno,
and V. Samavatian, “Effects of System Design on Fatigue Life
of Solder Joints in BGA Packages Under Vibration at Random
Frequencies,” J. Electron. Mater., vol. 47, no. 11, pp. 6781–
6790, Nov. 2018.
U. Choi, S. Jørgensen, and F. Blaabjerg, “Advanced
Accelerated Power Cycling Test for Reliability Investigation
of Power Device Modules,” IEEE Trans. Power Electron., vol.
31, no. 12, pp. 8371–8386, 2016.
X. Long, Q. P. Jia, Z. Li, and S. X. Wen, “Reverse analysis of
constitutive properties of sintered silver particles from
nanoindentations,” Int. J. Solids Struct., vol. 191–192, pp.
351–362, 2020.
X. Long, B. Hu, Y. Feng, C. Chang, and M. Li, “Correlation
of microstructure and constitutive behaviour of sintered silver
particles via nanoindentation,” Int. J. Mech. Sci., vol. 161–162,
p. 105020, 2019.
X. Long et al., “Mechanical behaviour of sintered silver
nanoparticles reinforced by SiC microparticles,” Mater. Sci.
Eng. A, vol. 744, pp. 406–414, 2019.
J. Wang, S. Xue, P. Zhang, P. Zhai, and Y. Tao, “The reliability
of lead-free solder joint subjected to special environment: a
review,” J. Mater. Sci. Mater. Electron., vol. 30, no. 10, pp.
9065–9086, 2019.
W. Wang, Z. Chen, S. Wang, and X. Long, “Mechanics-based
acceleration for estimating thermal fatigue life of electronic
packaging structure,” Microelectron. Reliab., vol. 107, p.
113616, 2020.
J. W. C. de Vries, M. Y. Jansen, and W. D. van Driel, “On the
difference between thermal cycling and thermal shock testing
for board level reliability of soldered interconnections,”
Microelectron. Reliab., vol. 47, no. 2, pp. 444–449, 2007.
A. Lupinacci, A. A. Shapiro, J. O. Suh, and A. M. Minor, “A
study of solder alloy ductility for cryogenic applications,” in
2013 IEEE International Symposium on Advanced Packaging
Materials, 2013, pp. 82–88.
R. Tian, C. Hang, Y. Tian, and L. Zhao, “Growth behavior of
intermetallic compounds and early formation of cracks in Sn3Ag-0.5Cu solder joints under extreme temperature thermal
shock,” Mater. Sci. Eng. A, vol. 709, pp. 125–133, 2018.
R. Tian, C. Hang, Y. Tian, and J. Xu, “Brittle fracture of Sn37Pb solder joints induced by enhanced intermetallic
7
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TCPMT.2020.3005215, IEEE
Transactions on Components, Packaging and Manufacturing Technology
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
compound growth under extreme temperature changes,” J.
Mater. Process. Technol., vol. 268, pp. 1–9, 2019.
R. Tian, C. Hang, Y. Tian, B. Wu, Y. Liu, and J. Zhao,
“Interfacial intermetallic compound growth in Sn-3Ag0.5Cu/Cu solder joints induced by stress gradient at cryogenic
temperatures,” J. Alloys Compd., vol. 800, pp. 180–190, 2019.
M. Samavatian, V. Samavatian, M. Moayeri, and H. Babaei,
“Effect of stress triaxiality on damage evolution of porous
solder joints in IGBT Discretes,” J. Manuf. Process., vol. 32,
pp. 57–64, Apr. 2018.
J. Fan, J. Wu, C. Jiang, H. Zhang, M. Ibrahim, and L. Deng,
“Random Voids Generation and Effect of Thermal Shock Load
on Mechanical Reliability of Light-Emitting Diode Flip Chip
Solder Joints,” Materials , vol. 13, no. 1. 2019.
V. Samavatian, H. Imaneini, and Y. Avenas, “Reliability
Assessment of Multistate Degraded Systems: An Application
to Power Electronic Systems,” IEEE Trans. Power Electron.,
p. 1, 2019.
E. H. Wong and Y.-W. Mai, “A unified equation for creepfatigue,” Int. J. Fatigue, vol. 68, pp. 186–194, 2014.
B. Talebanpour, U. Sahaym, and I. Dutta, “Effect of
Composition and Thermal–Mechanical History on the Creep
Behavior of Sn–Ag–Cu Solders—Part II: Model,” IEEE Trans.
Device Mater. Reliab., vol. 16, no. 3, pp. 326–335, 2016.
V. Ramachandran and K. Chiang, “Feasibility Evaluation of
Creep Model for Failure Assessment of Solder Joint Reliability
of Wafer-Level Packaging,” IEEE Trans. Device Mater.
Reliab., vol. 17, no. 4, pp. 672–677, 2017.
E. H. Amalu and N. N. Ekere, “Modelling evaluation of
Garofalo-Arrhenius creep relation for lead-free solder joints in
surface mount electronic component assemblies,” J. Manuf.
Syst., vol. 39, pp. 9–23, Apr. 2016.
M. T. Zarmai, N. N. Ekere, C. F. Oduoza, and E. H. Amalu,
“Evaluation of thermo-mechanical damage and fatigue life of
solar cell solder interconnections,” Robot. Comput. Integr.
Manuf., vol. 47, pp. 37–43, Oct. 2017.
A. Syed, “Accumulated creep strain and energy density based
thermal fatigue life prediction models for SnAgCu solder
joints,” in 2004 Proceedings. 54th Electronic Components and
Technology Conference (IEEE Cat. No.04CH37546), 2004,
vol. 1, pp. 737-746 Vol.1.
A. Surendar, V. Samavatian, A. Maseleno, A. Z. Ibatova, and
M. Samavatian, “Effect of solder layer thickness on thermomechanical reliability of a power electronic system,” J. Mater.
Sci. Mater. Electron., vol. 29, no. 17, pp. 15249–15258, Sep.
2018.
X. Long, Z. Chen, W. Wang, Y. Fu, and Y. Wu,
“Parameterized Anand constitutive model under a wide range
of temperature and strain rate: experimental and theoretical
studies,” J. Mater. Sci., vol. 55, no. 24, pp. 10811–10823,
2020.
W. J. Wang, X. Long, C. Y. Du, Y. H. Fu, Y. Yao, and Y. P.
Wu, “Enhancement of the Unified Constitutive Model for
Viscoplastic Solders in Wide Strain Rate and Temperature
Ranges,” Strength Mater., vol. 51, no. 6, pp. 917–925, 2019.
V. N. Le, L. Benabou, V. Etgens, and Q. B. Tao, “Finite
element analysis of the effect of process-induced voids on the
fatigue lifetime of a lead-free solder joint under thermal
cycling,” Microelectron. Reliab., vol. 65, pp. 243–254, Oct.
2016.
Y. C. Chan, D. J. Xie, and J. K. L. Lai, “Experimental studies
of pore formation in surface mount solder joints,” Mater. Sci.
Eng. B, vol. 38, no. 1, pp. 53–61, 1996.
M. Samavatian, V. Samavatian, M. Moayeri, and H. Babaei,
“Effect of stress triaxiality on damage evolution of porous
solder joints in IGBT Discretes,” J. Manuf. Process., vol. 32,
[33]
[34]
[35]
pp. 57–64, Apr. 2018.
M. T. Zarmai, N. N. Ekere, C. F. Oduoza, and E. H. Amalu,
“Optimization of thermo-mechanical reliability of solder joints
in crystalline silicon solar cell assembly,” Microelectron.
Reliab., vol. 59, pp. 117–125, 2016.
X. Long, X. He, and Y. Yao, “An improved unified creepplasticity model for SnAgCu solder under a wide range of
strain rates,” J. Mater. Sci., vol. 52, no. 10, pp. 6120–6137,
2017.
M. S. Srinath, A. K. Sharma, and P. Kumar, “A new approach
to joining of bulk copper using microwave energy,” Mater.
Des., vol. 32, no. 5, pp. 2685–2694, 2011.
8
2156-3950 (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Authorized licensed use limited to: University College London. Downloaded on July 04,2020 at 09:36:38 UTC from IEEE Xplore. Restrictions apply.