scholarly journals Critical Review of Size Effects on Microstructure and Mechanical Properties of Solder Joints for Electronic Packaging

2019 ◽  
Vol 9 (2) ◽  
pp. 227 ◽  
Author(s):  
Shaobin Wang ◽  
Yao Yao ◽  
Xu Long

With the miniaturization of electronic packaging and devices, the size of solder joints in electronics is also decreasing from bulk solder joints to micro-bumps. Both the microstructure and mechanical properties of the solder joints are also evolving with the decreasing size, which brings great concern for the reliability of different sizes of solder interconnections. In this paper, the effect of solder size on the microstructure (i.e., interfacial intermetallic compound (IMC) growth, precipitation in the solder matrix, dendrite arms, and undercooling) and mechanical properties (i.e., tensile property, shear and compression strength, fracture toughness, and creep deformation) are reviewed from the mechanical point of view. In addition, some areas for further researches about size effects on solder joints are discussed.

2017 ◽  
Vol 13 ◽  
pp. 9-14
Author(s):  
Alexander I. Tyurin ◽  
Andrey O. Zhigachev ◽  
Alexey V. Umrikhin ◽  
Vyacheslav V. Rodaev ◽  
Tatyana S. Pirozhkova

For the first time nanostructured engineering ceramics were prepared from natural zirconia mineral (baddeleyite) with CaO as a tetragonal phase stabilizer. The effect of synthesis conditions on microstructure and mechanical properties of the baddeleyite-based ceramics is reported, furthermore, the effect of calcia content on hardness and fracture toughness is studied. Optimal calcia concentration and synthesis conditions are found, corresponding hardness and fracture toughness values are 10,8 GPa and 13,3 MPa×m1/2. The reported mechanical properties are comparable to those typically reported for yttria-stabilized engineering zirconia ceramics, prepared from chemically synthesized zirconia.


2010 ◽  
Vol 105-106 ◽  
pp. 27-30 ◽  
Author(s):  
Wei Ru Zhang ◽  
Feng Sun ◽  
Ting Yan Tian ◽  
Xiang Hong Teng ◽  
Min Chao Ru ◽  
...  

Silicon nitride ceramics were prepared by gas pressure sintering (GPS) with different sintering additives, including La2O3, Sm2O3 and Al2O3. Effect of sintering additives on the phase-transformation, microstructure and mechanical properties of porous silicon nitride ceramics was investigated. The results show that the reaction of sintering additives each other and with SiO2 had key effects on the phase-transformation, grain growing and grain boundaries. With 9MPa N2 atmosphere pressure, holding 1h at 1850°C, adding 10wt% one of the La2O3, Sm2O3, Al2O3, porous silicon nitride was prepared and the relative density was 78%, 72%, 85% respectively. The flexural strength was less than 500MPa, and the fracture toughness was less than 4.8MPam1/2. Dropping compounds sintering additives, such as La2O3+Al2O3, Sm2O3+Al2O3 effectively improves the sintering and mechanical properties. The relative density was 99.2% and 98.7% with 10wt% compounds sintering additives. The grain ratio of length to diameter was up to 1:8. The flexural strength was more than 900MPa, and the fracture toughness was more than 8.9MPam1/2.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2224 ◽  
Author(s):  
Minai Zhang ◽  
Zhun Cheng ◽  
Jingmao Li ◽  
Shengguan Qu ◽  
Xiaoqiang Li

In this paper, WC-10Ni3Al cemented carbides were prepared by the powder metallurgy method, and the effects of ball-milling powders with two different organic solvents on the microstructure and mechanical properties of cemented carbides were studied. We show that the oxygen in the organic solvent can be absorbed into the mixed powders by ball-milling when ethanol (CH3CH2OH) is used as a ball-milling suspension. This oxygen leads to the formation of α-Al2O3 during sintering, which improves the fracture toughness, due to crack deflection and bridging, while the formation of η-phase (Ni3W3C) inhibits the grain growth and increases the hardness. Alternatively, samples milled using cyclohexane (C6H12) showed grain growth during processing, which led to a decrease in hardness. Therefore, the increase of oxygen content from using organic solvents during milling improves the properties of WC-Ni3Al composites. The growth of WC grains can be inhibited and the hardness can be improved without loss of toughness by self-generating α-Al2O3 and η-phase (Ni3W3C).


2020 ◽  
Vol 10 (13) ◽  
pp. 4435
Author(s):  
Qi Li ◽  
Guangchun Xiao ◽  
Zhaoqiang Chen ◽  
Runxin Guo ◽  
Mingdong Yi ◽  
...  

The Al2O3/Ti(C,N) ceramic material added micron ZrO2 whisker and nano coated CaF2@Al(OH)3 powder was fabricated. The micron ZrO2 whisker was for the toughening and reinforcing phase and the nano coated CaF2@Al(OH)3 powder was the lubricant. For obtaining a ceramic material with optimal comprehensive mechanical properties and friction properties, the influences of different compositions of the ZrO2 whisker and nano coated CaF2@Al(OH)3 powder on the microstructure and mechanical properties were analyzed, respectively. The result demonstrated that as the addition of the ZrO2 whisker was 6 vol% and the addition of the nano coated CaF2@Al(OH)3 powder was 10 vol%, the optimal self-lubricating ceramic material had optimal mechanical properties. The hardness of the ceramic material was 16.72 GPa, the flexural strength was 520 MPa and the fracture toughness reached 7.16 MPa·m1/2. The formation of the intragranular structure, whisker toughening and the phase transition of ZrO2 were the main mechanisms.


2008 ◽  
Vol 368-372 ◽  
pp. 1730-1732 ◽  
Author(s):  
Ping Hu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Song He Meng ◽  
Bao Lin Wang

SiC whisker-reinforced ZrB2 matrix ultra-high temperature ceramic were prepared at 2000°C for 1 h under 30MPa by hot pressing and the effects of whisker on flexural strength and fracture toughness of the composites was examined. The flexural strength and fracture toughness are 510±25MPa and 4.05±0.20MPa⋅m1/2 at room temperature, respectively. Comparing with the SiC particles-reinforced ZrB2 ceramic, no significant increase in both strength and toughness was observed. The microstructure of the composite showed that the SiC whisker was destroyed because the SiC whisker degraded due to rapid atom diffusivity at high temperature. The results suggested that some related parameters such as the lower hot-pressing temperature, a short sintering time should be controlled in order to obtain SiC whiskerreinforced ZrB2 composite with high properties.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2046 ◽  
Author(s):  
Yi Jing ◽  
Hongbing Yuan ◽  
Zisheng Lian

ZrB2–HfC ceramics have been fabricated using the liquid phase sintering technique at a sintering temperature as low as 1750 °C through the addition of Ni. The effects of HfC addition on the microstructure and mechanical properties of ZrB2–based ceramics have been investigated. These ceramics were composed of ZrB2, HfC, Ni, and a small amount of possible (Zr, Hf)B2 solid solution. Small HfC grains were distributed among ZrB2 grain boundaries. These small grains could improve the density of ZrB2–based ceramics and play a pinning role. With HfC content increasing from 10 wt % to 30 wt %, more HfC grains were distributed among ZrB2 grain boundaries, leading to weaker interface bonding among HfC grains; the relative density and Vickers hardness increased, and flexural strength and fracture toughness decreased. The weak interface bonding for 20 and 30 wt % HfC contents was the main cause of the decrease in both flexural strength and fracture toughness.


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