Effect of viscoelasticity of ethylene vinyl acetate encapsulants on photovoltaic module solder joint degradation due to thermomechanical fatigue
Open accessAbstract
Abstract The solder joint degradation due to thermomechanical fatigue is investigated in this paper for photovoltaic (PV) mini-modules with ethylene vinyl acetate (EVA) of different viscoelastic properties. The mini-modules were laminated at different curing temperatures in order to obtain EVA encapsulation with different viscoelastic properties. The influence of viscoelasticity of EVA on the thermomechanical fatigue generated on solder joint is analyzed based on a two-dimensional (2D) finite-element model. Based on simulation of thermomechanical stresses accumulation, mini-modules with EVA cured at lower temperatures accumulated approximately 40% more stresses during the thermal cycle testing than mini-modules with optimal cured EVA. The tested mini-modules with EVA cured at lower temperature showed greater power degradation than the optimal cured mini-modules. An apparent increase in equivalent series resistance is the primary factor the power loss. A good correlation between the accumulated thermomechanical fatigue and the increase in equivalent series resistance is demonstrated with the tested samples.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
0 of 9 cited sources checked · 0 supported · 0 flagged
- Findingown data
A good correlation exists between accumulated thermomechanical fatigue and increase in equivalent series resistance in the tested samples.
“A good correlation between the accumulated thermomechanical fatigue and the increase in equivalent series resistance is demonstrated with the tested samples.”
- Also stated in: § 3.2 Correlation of thermomechanical fatigue accumulation and series resistance degradation Simulations of thermomechanical fatigue accumulation on solder bonds are carried out for L125, L135, L145 and L150 samples.Figure 4 shows both the accumulated damage and cycling temperature for L125 samples.It can be identified that the thermomechanical fatigue accumulated largely during ramping periods.This is characteristic of the behavior of the solder that is explained by the hyperbolic sine term in Anand's model.The damage accumulation is faster when temperature ramps up from 50 to 85°C, as 1) the solder resistance to deformation is smaller at higher temperature; 32) and 2) the loss factor tanδ increases with the increasing temperature, which leads to higher energy dissipation and increased displacement.The loss factor decreases, when temperature ramps down.As temperature ramps down below 0°C and approaches the lower dwell temperature at -40°C, EVA material passes through the glass transition and the loss factor becomes higher again and therefore increasing the strain imposed on solder bonds.This simulation can be applied to all samples including L125, L135, L145 and L150.With EVA of different viscoelastic properties as indicated by the loss factor shown in Fig. 2, according to simulations, the L125 samples see about 40% more accumulated damage than the L150 samples do.correlation between the equivalent series resistance and the estimated fatiguing can be established.Changes in slopes of I-V curves are evident from the I-V measurements as plotted in Fig. 5 for L125 and L150 samples, respectively.Clear changes in slopes at V OC can be observed for the L125 sample, but no changes for the L150 sample.With the comparison analysis of extracted diode model parameters presented in Ref. 3), the equivalent series resistances for all mini-modules over TC test are evaluated.The averaged values and standard deviations of the equivalent series resistance for L125, L135, L145 and L150 samples are plotted in Fig. 6 against TC testing cycles.The L125 samples saw early increases in equivalent R S , which is followed by the L135 and L145 samples.The equivalent R S of L150 samples remained stable after 1400 cycles.The degradation of equivalent R S for L125, L135 and L145 samples tend to stabilize after a fast increase.This could be due to the ageing of EVA and other components of the module and their properties, therefore, can change over the course of ageing. The increase of equivalent R S is observed over time as a result of solder bond degradation and a correlation between the changes in R S and the thermomechanical fatigue is established and plotted in Fig. 7 for the L125, L135, L145 and L150 samples, respectively.Considering the nonlinear behaviour of solder joints degradation and change of equivalent R S , which are basically determined by material properties, the damage of thermomechanical stresses on solder joints is estimated by a Coffin-Manson type equation, 34) as , with S the generated thermomechanical stress, A and m are the constants found through least square regression represent the nonlinear degradation behaviours.Three stages of the degradation can be identified: 1) Initial thermomechanical fatigue accumulation before the increase in R S .This means there is an induction or initiation phase before rapid degradation takes place on solder bonds.This can be the initiation of crack on solder bonds.2) Thermomechanical fatigue led deformation of solder joints results in fast increase in R S .This can be the crack growth.3) Stabilization of R S .The stabilization of R S is not clearly understood and further investigation is required.But it could be explained by the fact that material's resistance to deformation increases with deformation.32) Another factor may be the PV material ages during the test, which minimizes the influences of thermomechanical fatigue on solder joints as well.V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L125 V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L150 · plain
“a correlation between the changes in R S and the thermomechanical fatigue is established and plotted in Fig. 7 for the L125, L135, L145 and L150 samples, respectively.”
- Also stated in: § 4. Conclusions · boosted
“the correlation between the accumulation of thermomechanical fatigue and the increase in the equivalent series resistance shows good agreement.”
Quote in the paperSubstantial claim - Also stated in: § 3.2 Correlation of thermomechanical fatigue accumulation and series resistance degradation Simulations of thermomechanical fatigue accumulation on solder bonds are carried out for L125, L135, L145 and L150 samples.Figure 4 shows both the accumulated damage and cycling temperature for L125 samples.It can be identified that the thermomechanical fatigue accumulated largely during ramping periods.This is characteristic of the behavior of the solder that is explained by the hyperbolic sine term in Anand's model.The damage accumulation is faster when temperature ramps up from 50 to 85°C, as 1) the solder resistance to deformation is smaller at higher temperature; 32) and 2) the loss factor tanδ increases with the increasing temperature, which leads to higher energy dissipation and increased displacement.The loss factor decreases, when temperature ramps down.As temperature ramps down below 0°C and approaches the lower dwell temperature at -40°C, EVA material passes through the glass transition and the loss factor becomes higher again and therefore increasing the strain imposed on solder bonds.This simulation can be applied to all samples including L125, L135, L145 and L150.With EVA of different viscoelastic properties as indicated by the loss factor shown in Fig. 2, according to simulations, the L125 samples see about 40% more accumulated damage than the L150 samples do.correlation between the equivalent series resistance and the estimated fatiguing can be established.Changes in slopes of I-V curves are evident from the I-V measurements as plotted in Fig. 5 for L125 and L150 samples, respectively.Clear changes in slopes at V OC can be observed for the L125 sample, but no changes for the L150 sample.With the comparison analysis of extracted diode model parameters presented in Ref. 3), the equivalent series resistances for all mini-modules over TC test are evaluated.The averaged values and standard deviations of the equivalent series resistance for L125, L135, L145 and L150 samples are plotted in Fig. 6 against TC testing cycles.The L125 samples saw early increases in equivalent R S , which is followed by the L135 and L145 samples.The equivalent R S of L150 samples remained stable after 1400 cycles.The degradation of equivalent R S for L125, L135 and L145 samples tend to stabilize after a fast increase.This could be due to the ageing of EVA and other components of the module and their properties, therefore, can change over the course of ageing. The increase of equivalent R S is observed over time as a result of solder bond degradation and a correlation between the changes in R S and the thermomechanical fatigue is established and plotted in Fig. 7 for the L125, L135, L145 and L150 samples, respectively.Considering the nonlinear behaviour of solder joints degradation and change of equivalent R S , which are basically determined by material properties, the damage of thermomechanical stresses on solder joints is estimated by a Coffin-Manson type equation, 34) as , with S the generated thermomechanical stress, A and m are the constants found through least square regression represent the nonlinear degradation behaviours.Three stages of the degradation can be identified: 1) Initial thermomechanical fatigue accumulation before the increase in R S .This means there is an induction or initiation phase before rapid degradation takes place on solder bonds.This can be the initiation of crack on solder bonds.2) Thermomechanical fatigue led deformation of solder joints results in fast increase in R S .This can be the crack growth.3) Stabilization of R S .The stabilization of R S is not clearly understood and further investigation is required.But it could be explained by the fact that material's resistance to deformation increases with deformation.32) Another factor may be the PV material ages during the test, which minimizes the influences of thermomechanical fatigue on solder joints as well.V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L125 V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L150 · plain
- Findingreasoning
Displacement of cells and interconnect ribbons can introduce significantly different stresses on module solder joints, as observed in this work.
“These cause displacement of cells and interconnect ribbons, which can introduce significantly different stresses on module solder joints as observed in this work.”
Quote in the paperSubstantial claim - Findingown data
Mini-modules with EVA cured at lower temperatures accumulated approximately 40% more thermomechanical stresses/damage during thermal cycle testing than mini-modules with optimally cured EVA.
“Based on simulation of thermomechanical stresses accumulation, mini-modules with EVA cured at lower temperatures accumulated approximately 40% more stresses during the thermal cycle testing than mini-modules with optimal cured EVA.”
- Also stated in: § 3.2 Correlation of thermomechanical fatigue accumulation and series resistance degradation Simulations of thermomechanical fatigue accumulation on solder bonds are carried out for L125, L135, L145 and L150 samples.Figure 4 shows both the accumulated damage and cycling temperature for L125 samples.It can be identified that the thermomechanical fatigue accumulated largely during ramping periods.This is characteristic of the behavior of the solder that is explained by the hyperbolic sine term in Anand's model.The damage accumulation is faster when temperature ramps up from 50 to 85°C, as 1) the solder resistance to deformation is smaller at higher temperature; 32) and 2) the loss factor tanδ increases with the increasing temperature, which leads to higher energy dissipation and increased displacement.The loss factor decreases, when temperature ramps down.As temperature ramps down below 0°C and approaches the lower dwell temperature at -40°C, EVA material passes through the glass transition and the loss factor becomes higher again and therefore increasing the strain imposed on solder bonds.This simulation can be applied to all samples including L125, L135, L145 and L150.With EVA of different viscoelastic properties as indicated by the loss factor shown in Fig. 2, according to simulations, the L125 samples see about 40% more accumulated damage than the L150 samples do.correlation between the equivalent series resistance and the estimated fatiguing can be established.Changes in slopes of I-V curves are evident from the I-V measurements as plotted in Fig. 5 for L125 and L150 samples, respectively.Clear changes in slopes at V OC can be observed for the L125 sample, but no changes for the L150 sample.With the comparison analysis of extracted diode model parameters presented in Ref. 3), the equivalent series resistances for all mini-modules over TC test are evaluated.The averaged values and standard deviations of the equivalent series resistance for L125, L135, L145 and L150 samples are plotted in Fig. 6 against TC testing cycles.The L125 samples saw early increases in equivalent R S , which is followed by the L135 and L145 samples.The equivalent R S of L150 samples remained stable after 1400 cycles.The degradation of equivalent R S for L125, L135 and L145 samples tend to stabilize after a fast increase.This could be due to the ageing of EVA and other components of the module and their properties, therefore, can change over the course of ageing. The increase of equivalent R S is observed over time as a result of solder bond degradation and a correlation between the changes in R S and the thermomechanical fatigue is established and plotted in Fig. 7 for the L125, L135, L145 and L150 samples, respectively.Considering the nonlinear behaviour of solder joints degradation and change of equivalent R S , which are basically determined by material properties, the damage of thermomechanical stresses on solder joints is estimated by a Coffin-Manson type equation, 34) as , with S the generated thermomechanical stress, A and m are the constants found through least square regression represent the nonlinear degradation behaviours.Three stages of the degradation can be identified: 1) Initial thermomechanical fatigue accumulation before the increase in R S .This means there is an induction or initiation phase before rapid degradation takes place on solder bonds.This can be the initiation of crack on solder bonds.2) Thermomechanical fatigue led deformation of solder joints results in fast increase in R S .This can be the crack growth.3) Stabilization of R S .The stabilization of R S is not clearly understood and further investigation is required.But it could be explained by the fact that material's resistance to deformation increases with deformation.32) Another factor may be the PV material ages during the test, which minimizes the influences of thermomechanical fatigue on solder joints as well.V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L125 V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L150 · hedged
“according to simulations, the L125 samples see about 40% more accumulated damage than the L150 samples do.”
Quote in the paperSubstantial claim - Also stated in: § 3.2 Correlation of thermomechanical fatigue accumulation and series resistance degradation Simulations of thermomechanical fatigue accumulation on solder bonds are carried out for L125, L135, L145 and L150 samples.Figure 4 shows both the accumulated damage and cycling temperature for L125 samples.It can be identified that the thermomechanical fatigue accumulated largely during ramping periods.This is characteristic of the behavior of the solder that is explained by the hyperbolic sine term in Anand's model.The damage accumulation is faster when temperature ramps up from 50 to 85°C, as 1) the solder resistance to deformation is smaller at higher temperature; 32) and 2) the loss factor tanδ increases with the increasing temperature, which leads to higher energy dissipation and increased displacement.The loss factor decreases, when temperature ramps down.As temperature ramps down below 0°C and approaches the lower dwell temperature at -40°C, EVA material passes through the glass transition and the loss factor becomes higher again and therefore increasing the strain imposed on solder bonds.This simulation can be applied to all samples including L125, L135, L145 and L150.With EVA of different viscoelastic properties as indicated by the loss factor shown in Fig. 2, according to simulations, the L125 samples see about 40% more accumulated damage than the L150 samples do.correlation between the equivalent series resistance and the estimated fatiguing can be established.Changes in slopes of I-V curves are evident from the I-V measurements as plotted in Fig. 5 for L125 and L150 samples, respectively.Clear changes in slopes at V OC can be observed for the L125 sample, but no changes for the L150 sample.With the comparison analysis of extracted diode model parameters presented in Ref. 3), the equivalent series resistances for all mini-modules over TC test are evaluated.The averaged values and standard deviations of the equivalent series resistance for L125, L135, L145 and L150 samples are plotted in Fig. 6 against TC testing cycles.The L125 samples saw early increases in equivalent R S , which is followed by the L135 and L145 samples.The equivalent R S of L150 samples remained stable after 1400 cycles.The degradation of equivalent R S for L125, L135 and L145 samples tend to stabilize after a fast increase.This could be due to the ageing of EVA and other components of the module and their properties, therefore, can change over the course of ageing. The increase of equivalent R S is observed over time as a result of solder bond degradation and a correlation between the changes in R S and the thermomechanical fatigue is established and plotted in Fig. 7 for the L125, L135, L145 and L150 samples, respectively.Considering the nonlinear behaviour of solder joints degradation and change of equivalent R S , which are basically determined by material properties, the damage of thermomechanical stresses on solder joints is estimated by a Coffin-Manson type equation, 34) as , with S the generated thermomechanical stress, A and m are the constants found through least square regression represent the nonlinear degradation behaviours.Three stages of the degradation can be identified: 1) Initial thermomechanical fatigue accumulation before the increase in R S .This means there is an induction or initiation phase before rapid degradation takes place on solder bonds.This can be the initiation of crack on solder bonds.2) Thermomechanical fatigue led deformation of solder joints results in fast increase in R S .This can be the crack growth.3) Stabilization of R S .The stabilization of R S is not clearly understood and further investigation is required.But it could be explained by the fact that material's resistance to deformation increases with deformation.32) Another factor may be the PV material ages during the test, which minimizes the influences of thermomechanical fatigue on solder joints as well.V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L125 V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 I (A) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 L150 · hedged
- Findingown data
Tested mini-modules with EVA cured at lower temperature showed greater power degradation than optimally cured mini-modules.
“The tested mini-modules with EVA cured at lower temperature showed greater power degradation than the optimal cured mini-modules.”
- Also stated in: § 3.1 Degradation of performance parameters · plain
“The mini-modules with EVA of high tanδ values, which would exhibit more significant displacement during TC test, showed greater degradation.”
Quote in the paperSubstantial claim - Also stated in: § 3.1 Degradation of performance parameters · plain
- Findingnone given
Different curing temperatures result in different viscoelastic behaviour of EVA.
“Different curing temperatures result in different viscoelastic behaviour of EVA.”
Quote in the paperSubstantial claim
- Findingown data
The L125 samples saw early increases in equivalent series resistance, followed by the L135 and L145 samples.
“The L125 samples saw early increases in equivalent R S , which is followed by the L135 and L145 samples.”
Quote in the paperSubstantial claim - Findingown data
The equivalent series resistance of L150 samples remained stable after 1400 cycles.
“The equivalent R S of L150 samples remained stable after 1400 cycles.”
Quote in the paperSubstantial claim - Findingreasoning
Mini-modules with EVA of high tanδ values showed greater degradation.
“The mini-modules with EVA of high tanδ values, which would exhibit more significant displacement during TC test, showed greater degradation.”
Quote in the paperSubstantial claim - Findingown data
The viscoelastic properties of EVA have a significant impact on the imposed strains of the solder bonds.
“The viscoelastic properties of the EVA have been shown to have a significant impact on the imposed strains of the solder bonds.”
Quote in the paperSubstantial claim - Findingreasoning
Damage accumulation is faster when temperature ramps up from 50 to 85°C.
“The damage accumulation is faster when temperature ramps up from 50 to 85°C”
Quote in the paperSubstantial claim - Findingown data
At temperatures above 50°C, the differences in tanδ between EVAs cured at the four conditions become bigger.
“At temperatures above 50°C, the differences become bigger.”
Quote in the paperSubstantial claim - Findingreasoning
The degradation of equivalent series resistance for L125, L135 and L145 samples tends to stabilize after a fast increase.
“The degradation of equivalent R S for L125, L135 and L145 samples tend to stabilize after a fast increase.”
Quote in the paperSubstantial claim - Findingreasoning
There is an initial thermomechanical fatigue accumulation before the increase in equivalent series resistance.
“1) Initial thermomechanical fatigue accumulation before the increase in R S .”
Quote in the paperSubstantial claim - Interpretationown data
An apparent increase in equivalent series resistance is the primary factor in the power loss.
“An apparent increase in equivalent series resistance is the primary factor the power loss.”
Quote in the paperSubstantial claim- The authors state this as an assumption: Thermomechanical fatigue generated during thermal cycle testing leads to ageing of solder bonds, which increases the equivalent series resistance.
- Premisereasoning
EVA bulk material of different viscoelastic properties responds to stresses differently under the same thermal condition.
“EVA bulk material of different viscoelastic properties responses to stresses differently under the same thermal condition.”
Quote in the paperSubstantial claim - Premisereasoning
PV laminates with EVA of different viscoelastic properties may exhibit different levels of strain during cyclic thermal conditions, leading to expansion or contraction of the laminate assembly.
“Additionally, PV laminates with EVA of different viscoelastic properties may exhibit different level of strain during cyclic thermal conditions, which lead to expansion or contraction of the laminate assembly.”
Quote in the paperSubstantial claim - Interpretationreasoning
Thermomechanical fatigue led deformation of solder joints results in fast increase in equivalent series resistance.
“2) Thermomechanical fatigue led deformation of solder joints results in fast increase in R S .”
Quote in the paperSubstantial claim- The authors state this as an assumption: Thermomechanical fatigue generated during thermal cycle testing leads to ageing of solder bonds, which increases the equivalent series resistance.
- Interpretationown data
There is an induction or initiation phase before rapid degradation takes place on solder bonds.
“This means there is an induction or initiation phase before rapid degradation takes place on solder bonds.”
Quote in the paperSubstantial claim
- Borderline: one of the tests for a substantial claim is unclear. 1
- May combine two claims. 9
- Classified as probably not a substantial claim. 5
Borderline on S1 (asserted), S3 (load-bearing), S4 (based): unclear from the text.
Findingnone givenThermomechanical fatigue accumulated largely during ramping periods.
“It can be identified that the thermomechanical fatigue accumulated largely during ramping periods.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataClear changes in slopes at VOC can be observed for the L125 sample, but no changes for the L150 sample.
“Clear changes in slopes at V OC can be observed for the L125 sample, but no changes for the L150 sample.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataThe L145 and L150 samples experienced less than 3% degradation after 400 cycles and degraded 13% and 6%, respectively, after 1400 cycles.
“The L145 and L150 samples showed good performance and experienced less than 3% degradation after 400 cycles and degraded 13% and 6%, respectively, after 1400 cycles.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataThe L135 samples experienced around 8% degradation after 400 cycles and about 30% power loss after 1400 cycles.
“This is followed by the L135 samples, which experienced around 8% degradation after 400 cycles and then degraded faster afterwards and saw power losses about 30% after 1400 cycles.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataThe L125 samples saw the largest PMPP degradation of more than 20% after 400 cycles and about 30% after 1400 cycles.
“The mini-modules with EVA cured at 125°C (referred to in the following as L125 samples, the same as for L135, L145 and L150 samples) saw the largest P MPP degradation of more than 20% after 400 cycles and about 30% after 1400 cycles.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim.
PremisecitationThe rate of solder fatiguing in different environments is not fully understood because it depends on factors such as thermomechanical properties of materials, stress levels, and material response.
“The rate of solder fatiguing in different environments is not fully understood as it depends on a variety of factors, such as thermomechanical properties of the various materials in a PV module as well as the detailed stress levels and the material response to these particular stress levels.[25][26][27][28]”
Quote in the paperSubstantial claim0 of 3 sources checkedClassified as probably not a substantial claim.
PremisecitationA study on the influence of different types of encapsulants on PV module solder joints demonstrates distinct difference in thermomechanical behavior for different encapsulants.
“However, a study on the influence of different types of encapsulants on PV module solder joints is carried out in Ref. 30), which demonstrates distinct difference in thermomechanical behavior for different encapsulants.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [30] Owen-Bellini, 2018, IEEE J. Photovoltaics source
Classified as probably not a substantial claim. May combine two claims.
PremisecitationThe encapsulant's role in thermomechanical fatigue generation is not clear, and its contribution to damage on solder bonds is rarely reported.
“It is, however, not clear its role in thermomechanical fatigue generation.Its contribution to damage on the solder bonds is rarely reported as its influence is not as critical as other components'.29)”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [29] Bosco, 2016, IEEE J. Photovoltaics source
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationPV module solder joint failure is a common failure mechanism widely observed in the field.
“PV module solder joint failure is a common failure mechanism that is widely observed in the field.[18][19][20][21][22][23][24]”
Quote in the paperNot a substantial claim0 of 3 sources checkedProbably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationThe material parameters for 60Sn40Pb solder alloy are well-defined in the literature.
“These material parameters for 60Sn40Pb solder alloy are well-defined in the literature 33) and are given in Table I below.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [33] Cheng, 2000, Soldering Surf. Mount Technol. source
May combine two claims.
Interpretationown dataThe degradation of power of different mini-modules appears to be due to FF losses, and shows similar curved pattern as the increase in series resistance.
“The degradation of power of different mini-modules appears to be due to FF losses, and shows similar curved pattern as the increase in series resistance.”
Quote in the paperSubstantial claimMay combine two claims.
InterpretationreasoningThe loss factor tanδ increases with increasing temperature, leading to higher energy dissipation and increased displacement.
“the loss factor tanδ increases with the increasing temperature, which leads to higher energy dissipation and increased displacement.”
Quote in the paperSubstantial claimMay combine two claims.
InterpretationreasoningAs temperature ramps down below 0°C and approaches -40°C, EVA passes through the glass transition and the loss factor becomes higher again, increasing the strain imposed on solder bonds.
“As temperature ramps down below 0°C and approaches the lower dwell temperature at -40°C, EVA material passes through the glass transition and the loss factor becomes higher again and therefore increasing the strain imposed on solder bonds.”
Quote in the paperSubstantial claimMay combine two claims.
InterpretationreasoningSamples cured at 125°C exhibit more significant displacement within the module assembly than the other samples, i.e. they are more elastic.
“This indicates that samples cured at 125°C exhibit more significant displacement within the module assembly than the other samples, i.e. they are more elastic.”
Quote in the paperSubstantial claim
The authors state this as an assumption.
Thermomechanical fatigue generated during thermal cycle testing leads to ageing of solder bonds, which increases the equivalent series resistance.
“The thermomechanical fatigue generated during TC test leads to ageing of solder bonds, which increases the equivalent series resistance (R S ).Based on this assumption, a”
“Based on this assumption of thermomechanical fatiguing leading to series resistance degradation, the correlation between the accumulation of thermomechanical fatigue and the increase in the equivalent series resistance shows good agreement.”
Cites
Constitutive equations for hot-working of metals
Anand, L. (1985) · International Journal of Plasticity · doi:10.1016/0749-6419(85)90004-x · Cited by 612 · see citing works
Compendium of photovoltaic degradation rates
Jordan, D. C., Kurtz, S. R., VanSant, K., & Newmiller, J. (2016) · Progress in Photovoltaics: Research and Applications · doi:10.1002/pip.2744 · Cited by 556 · see citing works
Photovoltaic failure and degradation modes
Jordan, D. C., Silverman, T. J., Wohlgemuth, J. H., Kurtz, S. R., & VanSant, K. T. (2017) · Progress in Photovoltaics: Research and Applications · doi:10.1002/pip.2866 · Cited by 375 · see citing works
Long Term Reliability of Photovoltaic Modules
Wohlgemuth, J., Cunningham, D., Monus, P., Miller, J., & Nguyen, A. (2006) · 2006 IEEE 4th World Conference on Photovoltaic Energy Conference · doi:10.1109/wcpec.2006.279905 · Cited by 148 · see citing works
Viscoplastic Anand model for solder alloys and its application
Cheng, Z. N., Wang, G. Z., Chen, L., Wilde, J., & Becker, K. (2000) · Soldering & Surface Mount Technology · doi:10.1108/09540910010331428 · Cited by 132 · see citing works
Performance Degradation of Various PV Module Technologies in Tropical Singapore
Ye, J. Y., Reindl, T., Aberle, A. G., et al. (2014) · IEEE Journal of Photovoltaics · doi:10.1109/jphotov.2014.2338051 · Cited by 120 · see citing works
Performance analysis of field exposed single crystalline silicon modules
Sastry, O. S., Saurabh, S., Shil, S. K., et al. (2010) · Solar Energy Materials and Solar Cells · doi:10.1016/j.solmat.2010.03.035 · Cited by 90 · see citing works
Changes of solar cell parameters during damp-heat exposure
Zhu, J., Koehl, M., Hoffmann, S., et al. (2016) · Progress in Photovoltaics Research and Applications · doi:10.1002/pip.2793 · Cited by 83 · see citing works
Self-citationPerformance and Aging of a 20-Year-Old Silicon PV System
Jordan, D. C., Sekulic, B., Marion, B., et al. (2015) · IEEE Journal of Photovoltaics · doi:10.1109/jphotov.2015.2396360 · Cited by 78 · see citing works
Wu, D., Zhu, J., Betts, T. R., et al. (2014) · Progress in Photovoltaics Research and Applications · doi:10.1002/pip.2460 · Cited by 57 · see citing works
Self-citationBerman, D., Biryukov, S., & Faiman, D. (1995) · Solar Energy Materials and Solar Cells · doi:10.1016/0927-0248(94)00198-7 · Cited by 45 · see citing works
The Influence of PV Module Materials and Design on Solder Joint Thermal Fatigue Durability
Bosco, N., Silverman, T. J., & Kurtz, S. (2016) · IEEE Journal of Photovoltaics · doi:10.1109/jphotov.2016.2598255 · Cited by 42 · see citing works
Herrmann, W., Bogdanski, N., Reil, F., Köhl, M., Weiss, K.-A., Assmus, M., & Heck, M. (2010) · SPIE Proceedings · doi:10.1117/12.859809 · Cited by 35 · see citing works
Singh, J., Belmont, J., & TamizhMani, G. (2013) · Conference record of the IEEE Photovoltaic Specialists Conference · doi:10.1109/pvsc.2013.6745149 · Cited by 34 · see citing works
Grid‐connected photovoltaic systems: the Brazilian experience and the performance of an installation
de Oliveira, S. H. F., & Zilles, R. (2001) · Progress in Photovoltaics Research and Applications · doi:10.1002/pip.384 · Cited by 18 · see citing works
Bending cyclic load test for crystalline silicon photovoltaic modules
Suzuki, S., Doi, T., Masuda, A., & Tanahashi, T. (2018) · Japanese Journal of Applied Physics · doi:10.7567/jjap.57.02ce05 · Cited by 13 · see citing works
Bogdanski, N., Herrmann, W., Reil, F., et al. (2010) · EU PVSEC · doi:10.4229/25theupvsec2010-4av.3.110 · Cited by 12 · see citing works
Owen-Bellini, M., Montiel-Chicharro, D., Zhu, J., Betts, T. R., & Gottschalg, R. (2018) · IEEE Journal of Photovoltaics · doi:10.1109/jphotov.2017.2762583 · Cited by 12 · see citing works
Self-citationPerformance of Thirty Years Stand Alone Photovoltaic System
Saleh, I. M., Abouhdima, I., & Gantrari, M. B. (2009) · EU PVSEC · doi:10.4229/24theupvsec2009-5do.7.6 · Cited by 8 · see citing works
Long-Term Performance Degradation of c-Si Photovoltaic Modules and Strings
Abenante, L., Lia, F. D., & Castello, S. (2010) · EU PVSEC · doi:10.4229/25theupvsec2010-4av.3.19 · Cited by 7 · see citing works
Long term performance analysis of PV module in the Gobi Desert of Mongolia
Adiyabat, A., Otani, K., Enebish, N., et al. (2010) · Conference record of the IEEE Photovoltaic Specialists Conference · doi:10.1109/pvsc.2010.5617116 · Cited by 7 · see citing works
TISO 10 kW: 30 Years Experience with a PV Plant
Friesen, T., Chianese, D., Realini, A., et al. (2012) · EU PVSEC · doi:10.4229/27theupvsec2012-4do.5.2 · Cited by 6 · see citing works
Analysis of the Degradation of 735 Commercial Crystalline Silicon Modules after First Operation Year
Coello, J., Cornacchia, F., & Muñoz, J. (2010) · EU PVSEC · doi:10.4229/25theupvsec2010-4av.3.18 · Cited by 3 · see citing works
Performance of c-Si Solar Cells After 25 Years of Operation
Messaoudi, A., & Bouazzi, A. S. (2008) · EU PVSEC · doi:10.4229/23rdeupvsec2008-5bv.3.1 · Cited by 3 · see citing works
(2014) · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · doi:10.1117/12.2176643 · Cited by 2 · see citing works
Towards modelling realistic ageing rates of amorphous silicon devices in operational environment
Zhu, J., Bliss, M., Betts, T. R., et al. (2015) · Japanese Journal of Applied Physics · doi:10.7567/jjap.54.08kg03 · Cited by 1 · see citing works
Self-citationPV Degradation Curves: Non-Linearities and Failure Modes
Jordan, D. C., Silverman, T. J., Sekulic, B., & Kurtz, S. R. (2016) · WIP · doi:10.4229/eupvsec20162016-5do.10.1 · Cited by 1 · see citing works
Flagged first, then by citations
Research works printed but not linked: 1
- Coffin, 1954, Trans. ASME, 76, 931
Cited by
Sorted by citations
Bosco, N., Springer, M., & He, X. (2020) · IEEE Journal of Photovoltaics · doi:10.1109/jphotov.2020.3005086 · Cited by 35 · see citing works
Chen, X., Karin, T., & Jain, A. (2024) · Applied Energy · doi:10.1016/j.apenergy.2024.124462 · Cited by 19 · see citing works
“Zhu et al. [14] fabricated different mini-modules and did a simulation to investigate the effect of viscoelasticity of encapsulant materials on the solder joint fatigue.”
BackgroundMansour, D. E., Herzog, C., Christöfl, P., et al. (2021) · Polymers · doi:10.3390/polym13193328 · Cited by 9 · see citing works
“It is also observed that the level of power degradation depends on the degree of EVA crosslinking [14,15].”
BackgroundOtnes, G., Lindholm, D., Fjær, H. G., et al. (2023) · Solar Energy Materials and Solar Cells · doi:10.1016/j.solmat.2023.112559 · Cited by 3 · see citing works
Investigation of Potting Compounds on Thermal-Fatigue properties of Solder Interconnects
Du, L., Zhao, X., Watté, P., et al. (2022) · Proceedings of the Annual Conference of the IEEE Industrial Electronics Society · doi:10.1109/iecon49645.2022.9968578 · Cited by 1 · see citing works
“Loss modulus, E’’, is a measure of the energy which is dissipated as heat during displacement and represents the viscous portion [11].”
BackgroundHealth Monitoring Fatigue Properties of Solder Interconnects in LED Drivers
Du, L., Zhao, X., Poelma, R. H., et al. (2024) · Springer eBooks · doi:10.1007/978-3-031-59361-1_13
- Authors
- Zhu, J., Owen-Bellini, M., Montiel-Chicharro, D., Betts, T. R., & Gottschalg, R.
- Affiliations
- Loughborough University (GB)
- Corresponding author
- Zhu, Jiang
- Venue
- Japanese Journal of Applied Physics
- Publisher
- IOP Publishing
- Published
- 2018-07-03
- Volume
- 57
- Issue
- 8S3
- Pages
- 08RG03
- ISSN
- 0021-4922 (ISSN-L)
- 1347-4065
- OpenAlex
- W2810021027
- Cited by
- 7
- References
- 27
- Citations by year
- 2024: 2 · 2023: 1 · 2022: 2 · 2021: 1 · 2020: 1
- FWCI
- 0.19
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- Locations
- Japanese Journal of Applied Physics (publishedVersion)
- Loughborough University Institutional Repository (Loughborough University) (submittedVersion, cc-by-nc-nd)
- Topics
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Electronic Packaging and Soldering Technologies
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Silicon and Solar Cell Technologies
- Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Solar Thermal and Photovoltaic Systems
- Keywords
- ethylene vinyl acetate, EVA encapsulation, solder joint degradation, thermomechanical fatigue, viscoelasticity, curing temperature, equivalent series resistance, power degradation, finite element analysis
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.
Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
