In situ observation of the void formation-and-propagation mechanism in solder joints under current-stressing

2005 ◽  
Vol 53 (7) ◽  
pp. 2029-2035 ◽  
Author(s):  
Y.H. Lin ◽  
Y.C. Hu ◽  
C.M. Tsai ◽  
C.R. Kao ◽  
K.N. Tu
Keyword(s):  
Solder Joints ◽  
Void Formation ◽  
Propagation Mechanism ◽  
In Situ Observation ◽  
Current Stressing

In-situ observation of material migration in flip-chip solder joints under current stressing

2006 ◽  
Vol 35 (10) ◽  
pp. 1781-1786 ◽  
Author(s):  
C. M. Tsai ◽  
Yi-Shao Lai ◽  
Y. L. Lin ◽  
C. W. Chang ◽  
C. R. Kao
Keyword(s):  
Flip Chip ◽  
Solder Joints ◽  
In Situ Observation ◽  
Current Stressing ◽  
Material Migration

scholarly journals The In-Situ Observation of Grain Rotation and Microstructure Evolution Induced by Electromigration in Sn-3.0Ag-0.5Cu Solder Joints

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5497
Author(s):  
Xing Fu ◽  
Min Liu ◽  
KeXin Xu ◽  
Si Chen ◽  
YiJun Shi ◽  
...  
Keyword(s):  
Solder Joints ◽  
Flow Direction ◽  
Electron Flow ◽  
Critical Role ◽  
In Situ Observation ◽  
Fast Diffusion ◽  
Electron Backscattered Diffraction ◽  
Grain Rotation ◽  
Current Stressing

The in-situ observation of Sn-3.0Ag-0.5Cu solder joints under electromigration was conducted to investigate the microstructure and grain orientation evolution. It was observed that there was a grain rotation phenomenon during current stressing by in-situ electron backscattered diffraction (EBSD). The rotation angle was calculated, which indicated that the grain reorientation led to the decrease of the resistance of solder joints. On the other hand, the orientation of β-Sn played a critical role in determining the migration of Cu atoms in solder joints under current stressing migration. When the angle between the electron flow direction and the c-axis of Sn (defined as α) was close to 0°, massive Cu6Sn5 intermetallic compounds were observed in the solder bulk; however, when α was close to 90°, the migration of the intermetallic compound (IMC) was blocked but many Sn hillocks grew in the anode. Moreover, the low angle boundaries were the fast diffusion channel of Cu atoms while the high grain boundaries in the range of 55°–65° were not favorable to the fast diffusion of Cu atoms.

In Situ Observation of Crack Propagation in Epoxy Composite Reinforced with Crushed Silica Particles

2010 ◽  
Vol 452-453 ◽  
pp. 753-756
Author(s):  
Alisa Boonyapookana ◽  
Yoshiharu Mutoh ◽  
Kohsoku Nagata
Keyword(s):  
Crack Propagation ◽  
Crack Growth ◽  
Main Crack ◽  
Resin Composite ◽  
Silica Particles ◽  
Propagation Mechanism ◽  
In Situ Observation ◽  
Epoxy Resin Composite ◽  
Crack Propagation Mechanism

In-situ observation of fatigue crack growth of epoxy resin composite reinforced with crushed silica particle was carried out. The test was performed under constant ΔK condition. Based on the results, the crack propagation mechanism was discussed. The in-situ observation revealed that in front of the main crack, a microcrack was nucleated at the interface of matrix/particle and then coalesced with the main crack. At the same time, new microcracking occurred ahead of the crack tip and the crack propagated by repeating these processes. Retardation of crack growth rate was found to result from crack bridging induced by microcracking at silica particles and crack deflection.

In Situ Soldering Process Technique by Synchrotron X-Ray Imaging

2015 ◽  
Vol 754-755 ◽  
pp. 508-512
Author(s):  
M.A.A. Mohd Salleh ◽  
A. Sugiyama ◽  
Hideyuki Yasuda ◽  
Stuart D. McDonald ◽  
Kazuhiro Nogita
Keyword(s):  
Real Time ◽  
Void Formation ◽  
In Situ Observation ◽  
Cu Substrate ◽  
X Ray ◽  
Soldering Process ◽  
X Ray Imaging ◽  
Free Solder ◽  
First Time

This paper demonstrates the development of an experimental technique of in-situ observation for soldering of Sn-0.7wt%Cu lead-free solder on a Cu substrate which was achieved for the first time by synchrotron X-ray imaging. Reactions between liquid solder and Cu substrate during a soldering process were able to be recorded in real-time. Individual stages of the soldering process consisted of flux activation in removal of Cu oxide, solder melting and contact with the Cu substrate (wetting) and intermetallic compound (IMC) and void formation between the solder and Cu substrate. The technique development which includes experimental setup with calculated optimum beam energy in the range of 20 – 30 keV appears to result in a clear observation of real-time X-ray imaging of the soldering process. This technique provides a key method to understand the mechanism of formation of micro-electronic inter-connects for future electronic packaging applications.

In situ observation of void evolution in 1,3,5-triamino-2,4,6-trinitrobenzene under compression by synchrotron radiation X-ray nano-computed tomography

2020 ◽  
Vol 27 (1) ◽  
pp. 127-133 ◽  
Author(s):  
Liang Chen ◽  
Lihui Wu ◽  
Yu Liu ◽  
Wei Chen
Keyword(s):  
Computed Tomography ◽  
Energetic Materials ◽  
Void Formation ◽  
Volume Ratio ◽  
In Situ Observation ◽  
Continuous Growth ◽  
X Ray ◽  
Irregular Structures ◽  
Computed Tomography Images

The formation and development of voids in 1,3,5-triamino-2,4,6-trinitrobenzene crystals under compression were characterized in situ by X-ray nano-computed tomography. Benefiting from high spatial resolution (30 nm) and excellent imaging contrast, the X-ray nano-computed tomography images revealed the presence of a small fraction of inhomogeneous structures in the original crystal (volume ratio ∼1.2%). Such an inhomogeneity acts as a nucleation of voids and produces stress concentration during compression, which leads to continuous growth of the voids under loading. Meanwhile, the results further reveal that the developing voids are not isotropic: voids with higher surface roughness and irregular structures are easier to break and form new micro-voids. These new voids with higher irregular structures are weaker and easier to break into smaller ones compared with the originals, leading to the development of voids along these weak zones. Finally large voids form. The experiments allow direct investigation of void formation and development, which helps in studying the mechanisms of void development and energetic materials deterioration during manufacturing and transporting.

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