Slow Cycle Fatigue Creep Performance of Pb-Free (LF) Solders

Vasudevan, Vasu; Fan, Xuejun; Liu, Tao; Young, D.

doi:10.1109/ectc.2007.373785

Cited by 12 publications

(9 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, temperature, and cycle time still have significant impact on the thermal fatigue life of SAC solder joints, as shown from the test data above. The impact of the extended cycle time on solder joint reliability for both Sn/Pb and SAC 405 has been characterized by Vasudevan et al [1] and showed no cross-over for both Sn/Pb and LF even after 8 hrs cycle time. Both Sn/Pb and LF solder showed decrease in fatigue performance with the increase in dwell time.…”

Section: Acceleration Modelmentioning

confidence: 95%

“…Both SAC105 and SAC405 data are shown in Table 1 and the temp behavior is similar for both alloys. The experimental test procedures were provided in our previous paper [1]. An Air to air temperature cycle test was used.…”

Section: Experimental Data Collectionmentioning

confidence: 99%

“…Finite Element Analysis (FEA) has been utilized extensively to calculate the plastic strain range or plastic strain density range [1][2][3][4][5][16][17][18][19]. Finite element models can take into consideration the interaction among components in an assembly with little or no geometric simplification.…”

Section: Review: Lifetime Prediction Models For Solder Joint Fatiguementioning

confidence: 99%

“…Numerous studies have been published regarding the thermal cycling reliability of SnAgCu solder joints under accelerated test conditions [e.g., [1][2][3][4][5]. The acceleration factor (AF) models for LF are of particular interests to the electronics industry for the simple reason that the solder joint reliability in field power cycling conditions can be predicted in a simple yet accurate manner.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

An acceleration model for lead-free (SAC) solder joint reliability under thermal cycling

Vasudevan

Fan

2008

2008 58th Electronic Components and Technology Conference

Self Cite

View full text Add to dashboard Cite

The electronics industry has successfully transitioned from Sn/Pb to Pb free (LF) solder for computing and consumer electronics applications. However, there is no industry-wide standardized LF solder joint reliability model (neither empirical nor FEA-based) available for solder fatigue reliability assessment. A LF solder fatigue model has been proposed in this paper based on a 3-parameter modified Coffin-Manson approach. The proposed model showed best fit to the experimental data (17 pairs of temperature cycle test data) from different sources for multiple package types and sizes including various test conditions. The model fit to the experimental data was excellent and the error was less than 6%. This analysis showed that the LF acceleration factor (AF) model is not significantly different from the Sn/Pb model and proposed model provides best fit to experimental results. IntroductionWhile the electronics industry has successfully completed the transition to Pb-free (LF) technology for computing and consumer electronics applications, there is still no standardized LF solder joint reliability model (neither empirical nor FEA-based) available for solder fatigue. Numerous studies have been published regarding the thermal cycling reliability of SnAgCu solder joints under accelerated test conditions [e.g., 1-5]. The acceleration factor (AF) models for LF are of particular interests to the electronics industry for the simple reason that the solder joint reliability in field power cycling conditions can be predicted in a simple yet accurate manner. Pan et al [6] first attempted to obtain an acceleration factor model using several thermal cycle profiles, in which the temperature range, maximum temperature and the cycle time or frequency were systematically varied. However, it has been shown in several studies [7,8] that this model prediction is not well correlated with experimental results. Studies by Salmela [8], and Zhang and Clech [7] evaluated several different types of AF models. Those AF models also include models based on the compact strain energy analysis and the finite element analysis. It showed that the FEA based models have limited success in predicting the AF factors, especially when test conditions and package types vary dramatically.In this paper, a LF acceleration factor model is proposed based on the Norris-Landzberg equation. A total of 17 pairs of experimental data suitable for acceleration factor computations, taken from Intel and industry published test data, were used to calibrate and support the model. These data

show abstract

Section: Acceleration Modelmentioning

confidence: 95%

Section: Experimental Data Collectionmentioning

confidence: 99%

Section: Review: Lifetime Prediction Models For Solder Joint Fatiguementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

An acceleration model for lead-free (SAC) solder joint reliability under thermal cycling

Vasudevan

Fan

2008

2008 58th Electronic Components and Technology Conference

Self Cite

View full text Add to dashboard Cite

show abstract

“…The per-cycle inelastic strain (or creep strain) or inelastic strain energy density is used as damage metrics to evaluate solder joint reliability [20][21][22][23][24][25][26]. For example, the volume averaged inelastic energy density over the 10 µm thin disk is defined as follows,…”

Section: Finite Element Modelsmentioning

confidence: 99%

Reliability enhancement of wafer level packages with nano-column-like hollow solder ball structures

Varia

Fan

2011

2011 IEEE 61st Electronic Components and Technology Conference (ECTC)

Self Cite

View full text Add to dashboard Cite

In this paper, hollowed solder ball structures in wafer level packages are investigated. Detailed 3-D finite element modelling is conducted for stress and accumulated inelastic strain energy density or creep strain analysis. Three cases are studied in this paper: a regular solder ball, a solder ball with a polymer core of sphere shape, and a hollowed solder ball. Two different creep models are applied: 1) anand model; and 2) hyperbolic sine creep model. Testing data of polymer-cored solder ball WLP are used for verification. Hollowed ball WLP appears to have further improved thermal-cycling performance. When anand model is used, some unexpected results are obtained: 1) maximum inelastic strain energy density and von Mises stress occur in the balls of the middle of the diagonal row; and 2) von Mises stress is almost equally distributed among all balls. However, when hyperbolic sine creep model is used, the obtained results are consistent with the observations in conventional solder ball WLP. Nevertheless, both creep models predict the significant reduction in solder ball stress and accumulated creep strain or inelastic strain energy density for hollow ball WLP. Existing experimental results of polymer-cored WLP from literature can indirectly validate the benefit from hollowed balls.

show abstract

Thermal Stresses in Wafer-Level Packaging

Fan

2014

Encyclopedia of Thermal Stresses

View full text Add to dashboard Cite

Slow Cycle Fatigue Creep Performance of Pb-Free (LF) Solders

Cited by 12 publications

References 7 publications

An acceleration model for lead-free (SAC) solder joint reliability under thermal cycling

An acceleration model for lead-free (SAC) solder joint reliability under thermal cycling

Reliability enhancement of wafer level packages with nano-column-like hollow solder ball structures

Thermal Stresses in Wafer-Level Packaging

Contact Info

Product

Resources

About