scholarly journals The Effect of Grain Orientation of β-Sn on Copper Pillar Solder Joints during Electromigration

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 108
Author(s):  
Kexin Xu ◽  
Xing Fu ◽  
Xinjie Wang ◽  
Zhiwei Fu ◽  
Xiaofeng Yang ◽  
...  
Keyword(s):  
Electric Current ◽  
Grain Orientation ◽  
Solder Joints ◽  
Metal Dissolution ◽  
Wind Force ◽  
Electron Backscattered Diffraction ◽  
Combined Action ◽  
Free Solder ◽  
Electron Wind ◽  
A Current

The grain orientation of Sn-based solder joints on copper pillars under the combined action of electron wind force and temperature gradient greatly affects their electromigration damage. The copper pillars with Sn-1.8Ag lead-free solder on the top was subjected to a current density of 1.5 × 104 A/cm2 at 125 °C to study the electromigration behaviors. The grain orientation was characterized by scanning electron microscopy (SEM) equipped with electron backscattered diffraction (EBSD) detector. Metal dissolution and voids formation in the cathode as well as massive intermetallic compounds(IMC) accumulation in the anode were observed after electromigration. Closer examination of solder joints revealed that the Sn grain whose c-axis perpendicular to electric current may have retarded Cu diffusion to anode and IMC accumulation. In addition, the newly formed Cu6Sn5 exhibited preferred orientation related to the electric current direction.

Electromigration and thermomigration behavior of flip chip solder joints in high current density packages

2008 ◽  
Vol 23 (9) ◽  
pp. 2333-2339 ◽  
Author(s):  
D. Yang ◽  
Y.C. Chan ◽  
B.Y. Wu ◽  
M. Pecht
Keyword(s):  
Flip Chip ◽  
Solder Joints ◽  
High Current Density ◽  
Dominant Role ◽  
Current Crowding ◽  
Wind Force ◽  
Cross Sectional ◽  
Ambient Temperatures ◽  
Atomic Flux ◽  
Electron Wind

The electromigration and thermomigration behavior of eutectic tin-lead flip chip solder joints, subjected to currents ranging from 1.6 to 2.0 A, at ambient temperatures above 100 °C, was experimentally and numerically studied. The temperature at the chip side was monitored using both a temperature coefficient of resistance method and a thermal infrared technique. The electron wind force and thermal gradient played the dominant role in accelerated atomic migration. The atomic flux of lead due to electromigration and thermomigration was estimated for comparison. At the current crowding region, electromigration induced a more serious void accumulation as compared with thermomigration. Also, because of different thermal dissipations, a morphological variation was detected at different cross-sectional planes of the solder joint during thermomigration.

Influence of the Electric Current Pulse with Different Pulse Width on the Eutectoid Microstructure of Hypoeutectic Fe-C Alloys

2014 ◽  
Vol 852 ◽  
pp. 208-213
Author(s):  
Zheng Yang Huang ◽  
Qi Hong Cen ◽  
Zhen Hua Li ◽  
Ying Wu ◽  
Lei Zou
Keyword(s):  
Electric Current ◽  
Current Pulse ◽  
Joule Heating ◽  
Pulse Width ◽  
Dislocation Motion ◽  
Electric Current Pulse ◽  
Wind Force ◽  
Cementite Dissolution ◽  
Pile Up ◽  
Electron Wind

The influence of the eutectoid structure of hypoeutectic Fe-C alloys by applying electric current pulse (ECP) is carried out. The experiment results show that ECP treatment can produce Joule heating. Joule heating increases the diffusion capability of atoms and the driving force of austenite growth, which promotes austenite crystal growth and accelerate cementite dissolution. In view of the influence of the electron-wind-force made by ECP, it can increase the quantity of moving dislocation. The dislocation pile-up which made by the dislocation motion lead to cementite dissolution. Cementite dissolution can lead to concentration fluctuation in Austenite. ECP can also make the phase transformation barrier and the phase transition drive force of graphite formation decrease. As the result, these phenomena can make cryogenic ledeburite become less and graphite increase. Furthermore, it can also increase the nucleation rate and growth rate of ferrite, which can make the relative amount of ferrite increase and the relative amount of pearlite decrease. Based on our experiments, the effect becomes more obvious with the pulse width increase.

Electric Current Induced Brittle Failure of Eutectic Lead and Lead-free Solder Joints with Electroless Ni-P Metallization

2006 ◽  
Vol 968 ◽  
Author(s):  
Aditya Kumar ◽  
Zhong Chen ◽  
C. C. Wong ◽  
S. G. Mhaisalkar ◽  
Vaidhyanathan Kripesh
Keyword(s):  
Solder Joint ◽  
Electric Current ◽  
Brittle Failure ◽  
Tensile Testing ◽  
Solder Joints ◽  
Lead Free ◽  
Cathode Side ◽  
Lead Free Solder ◽  
Free Solder ◽  
Electroless Ni

ABSTRACTThe mechanical properties of thermally-aged and electric current-stressed eutectic lead (Sn-37Pb) and lead-free (Sn-3.5Ag) solder joints with electroless Ni-P metallization were investigated using tensile testing. Multi-layered test samples, electroless Ni-P/solder/electroless Ni-P, having two electroless Ni-P/solder interfaces were prepared. Tensile testing results showed that for both types of solder, high density electric current causes the brittle failure of solder joint. The eutectic lead solder joint was found to be more prone to current induced brittle failure compared to the lead-free solder joint. In the eutectic lead solder joint, brittle failure always occurred at the cathode side electroless Ni-P/Sn-37Pb interface (where electrons flowed from Ni-P to solder), whereas no such polarity effect was observed in the case of lead-free solder joint.

The Isotope Effect of a Direct Electric Current through Liquid and Solid Metals

1956 ◽  
Vol 11 (1) ◽  
pp. 71-75
Author(s):  
E. Haeffner ◽  
Th. Sjöborg ◽  
S. Lindhe
Keyword(s):  
Liquid Metal ◽  
Electric Current ◽  
Isotope Effect ◽  
Direct Current ◽  
Capillary Tube ◽  
Isotope Separation ◽  
Direct Electric Current ◽  
Separation Effect ◽  
A Current

The isotope separation effect of a direct electric current in a liquid metal is demonstrated by passing a current through mercury, which is enclosed in a capillary tube. The second part of the paper deals with an attempt of establishing an isotope effect when a direct current is passed through an uranium wire.

Void Formation and Their Effect on Reliability of Lead-Free Solder Joints on MID and PCB Substrates

2017 ◽  
Vol 66 (4) ◽  
pp. 1229-1237 ◽  
Author(s):  
P. Wild ◽  
T. Grozinger ◽  
D. Lorenz ◽  
A. Zimmermann
Keyword(s):  
Solder Joints ◽  
Void Formation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder

Quantitative Evaluation of Voids in Lead Free Solder Joints

2015 ◽  
Vol 772 ◽  
pp. 284-289 ◽  
Author(s):  
Sabuj Mallik ◽  
Jude Njoku ◽  
Gabriel Takyi
Keyword(s):  
Solder Bump ◽  
Solder Joints ◽  
Void Formation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Paste ◽  
X Ray ◽  
Size And Shape ◽  
Solder Bumps ◽  
Free Solder

Voiding in solder joints poses a serious reliability concern for electronic products. The aim of this research was to quantify the void formation in lead-free solder joints through X-ray inspections. Experiments were designed to investigate how void formation is affected by solder bump size and shape, differences in reflow time and temperature, and differences in solder paste formulation. Four different lead-free solder paste samples were used to produce solder bumps on a number of test boards, using surface mount reflow soldering process. Using an advanced X-ray inspection system void percentages were measured for three different size and shape solder bumps. Results indicate that the voiding in solder joint is strongly influenced by solder bump size and shape, with voids found to have increased when bump size decreased. A longer soaking period during reflow stage has negatively affectedsolder voids. Voiding was also accelerated with smaller solder particles in solder paste.

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