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To verify the reliability of a typical Pb-free circuit board applied for space exploration, five circuits were put into low temperature and shock test. However, after the test, memories on all five circuits were out of function. To investigate the cause of the failure, a series of methods for failure analysis was carried out, including X-ray detect...
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... Another important requirement for the LFS application is their reliability in a wide range of operating temperatures, in particular at low temperatures, because for, e.g., application in aerospace conditions, it is important to know the characteristics of the mechanical properties behavior of components during operation in extreme thermodynamic conditions (Wu et al. 2021;Li et al. 2020;Lupinacci et al. 2013;Li et al. 2017). The use of such solders in microelectronic devices at cryogenic temperatures may not be suitable, as Sn-based solders can become brittle due to the allotropic phase transformation of tin, known as "tin pest". ...
An influence of carbon nanotubes and carbon nanospheres coated by Au–Pd and Pt on the microstructure of solder/copper joints at room temperature and after aging at sub-zero temperature. The carbon nanosized admixtures were mixed with ternary Sn3.0Ag0.5Cu matrix to prepare a composite solder. The microstructure of the solder joints between the nanocomposite solders and a copper substrate was studied by scanning electron microscopy. It was found that minor (0.05 wt. %) admixtures of both the carbon nanospheres and nanotubes increase the shear strength of the solder joints and reduce the growth rate of the intermetallic Cu 6 Sn 5 layer, formed at the interface between solder and copper. This effect may be related to the adsorption of nanoinclusions on the grain surface during the solidification process. Comparative analysis suggests that exposure for 2 months at 253 K does not lead to deterioration of such an important mechanical characteristic of the solder joint as shear strength, indicating the possibility of using these nanocomposite solders in microelectronic equipment even at temperatures below 0 ℃.
... Li et al. [42] investigated the failure mechanism of SAC305 BGA solder joints under − 100 ℃. At − 100 ℃, the fracture characteristic of SAC305 solder joints was brittleness, which was different from ductile fracture under room temperature (RT). ...
The spacecraft for deep space exploration missions will face extreme environments, including cryogenic temperature, intense radiation, wide-range temperature variations and even the combination of conditions mentioned above. Harsh environments will lead to solder joints degradation or even failure, resulting in damage to onboard electronics. The research activities on high reliability solder joints using in extreme environments can not only reduce the use of onboard protection devices, but effectively improve the overall reliability of spacecraft, which is of great significance to the aviation industry. In this paper, we review the reliability research on SnPb solder alloys, Sn-based lead-free solder alloys and In-based solder alloys in extreme environments, and try to provide some suggestions for the follow-up studies, which focus on solder joint reliability under extreme environments.
... Nie znaczy to jednak, że problem został definitywnie rozwiązany, gdyż po kilku latach użytkowania połączenie rdzenia układu z obudową ulegają degradacji. Nie jest to jednak okres tak krótki jak w pierwszych czterech latach po wejściu RoHS I [5][6][7]. ...
The paper discusses the concept of soldering profile and its phases and examines the influence of ambient temperature on its workability. The author carried out an experiment on two identical PCBs at different room temperatures, observing the temperature waveforms for individual soldering phases.
... In a deep space environment, the exploration equipment with complex electric systems suffers from extreme thermal shocks, inducing material performance degradation and further leading to the failure of electronic packaging. The reasons could be clarified by the research on the reliability of Sn/Pb and SnAgCu solder packaging which shows vulnerability to thermal shocks of Pb-free solders and Sn/Pb solders [1,2]. Therefore, finding alternative green bonding materials to adapt to the space environment has become an urgent research hotspot. ...
With excellent economy and properties, pressureless sintered micron silver has been regarded as an environmentally friendly interconnection material. In order to promote its reliable application in deep space exploration considering the porous microstructural evolution and its effect on macroscopic performance, simulation analysis based on the reconstruction of pressureless sintered micron silver joints was carried out. In this paper, the deep space environment was achieved by a test of 250 extreme thermal shocks of −170 °C~125 °C, and the microstructural evolution was observed by using SEM. Taking advantage of the morphology autocorrelation function, three-dimensional models of the random-distribution medium consistent with SEM images were reconstructed, and utilized in further Finite Element Analysis (FEA) of material effective elastic modulus through a transfer procedure. Compared with test results and two analytical models, the good consistency of the prediction results proves that the proposed method is reliable. Through analyzing the change in autocorrelation functions, the microstructural evolution with increasing shocks was quantitively characterized. Mechanical response characteristics in FEA were discussed. Moreover, the elasticity degradation was noticed and the mechanism in this special environment was clarified.
This paper presents a framework for failure mechanism-based reliability assessment, starting from collecting failed field samples. The framework includes failure analysis for identifying the failure mechanism and accelerated life tests (ALTs) for reproducing the failure mechanism. We consider that relevant information, such as warranty data and qualification test results, enables to be utilized in the framework. The proposed framework is validated by using it to identify the failure mechanism and estimate the lifetime of an automotive component under normal use conditions. The case study shows that the framework enables to quantitatively assess reliability based on the failure mechanism.
