چکیده:
In this research, analysis of the reliability of lead-free soldering was investigated and a
qualitative analysis was discussed about fracture modes of lead-free solder under different
tensional tests such as: releasing test, bending test, thermal test and vibration test. Cracks
caused by fatigue is the main reason of lead-free soldering`s fracture ؛primary cracking
speed can change according to the different test conditions and different soldering materials.
A quantitative analysis was also carried out on the behavior of lead-free soldering`s fatigue
SAC (copper and silver) under preheating conditions. This dissertation presents a method
for predicting the fracture lifetime of soldering alloys by creating the Weibull regression
model. The lifetime of solder fracture is supposed on orbital board which was been
distributed in the form of Weibull. Different test materials and conditions can affect
distribution following changes of formation parameters and Weibull distribution scale. The
method used in this thesis is modeling regression of parameters under different test
conditions as a predictor based on Bayesian inference concepts. In the process of creating
regression models, former distributions are done according to previous studies and the
Monte Carlo Markov Chain (MCMC) has been used under the WinBUGS environment. The
results showed that in general, lead-free solder alloy shows a good fracture lifetime. The
alloy with a low mercury had a higher fracture lifetime While the alloy with a high mercury
value had a longer fracture lifetime under the thermal precondition process.
خلاصه ماشینی:
"When the applied load is below 37 N, the SAC405 has a longer lifetime failure rate, while at a load above Sn37Pb, N37 shows better reliability than lead-free alloy.
Cycle Thermal Test - Longer lifetimes of SAC alloys than lead-based alloys in thermal cyclic tests Finite element modeling is a suitable method for simulating stress and strain distribution on solder joints.
UCT Journal of Research in Science, Engineering and Technology (به تصویر صفحه مراجعه شود) Figure 2-1 Diagnostic Diagram - Gelman-Rubin Initial Run with 10,000 Repetition and 1000 Burn-in Repeats In addition, the correlation diagrams β0 and β4 in Figs.
(به تصویر صفحه مراجعه شود) Figure 2-4 Revised Gelman-Rubin Diagram Diagrams As in Fig. 3, diagrams (a) and (c) of the records of the parameters are β0 and β4, the path of the records of these two parameters is strongly correlated with the repetitions, and two chains are separated from each other, which is UCT Journal of Research in Science, Engineering and Technology based on a poor sampling of The model implies, however, after modifying the model with 100,000 repetitions and 20 (به تصویر صفحه مراجعه شود) intervals, the charts seem to have improved.
2. The Weibull regression model in the WinBUGS environment using Bayesian inference, along with Meta data analysis from previous studies, was conducted to investigate the non-lead soldered bond failure test under a heat test."