Electric current effect on microstructure of ball grid array solder joint

2005 ◽  
Vol 392 (1-2) ◽  
pp. 237-246 ◽  
Author(s):  
B.Y. Wu ◽  
Y.C. Chan
Keyword(s):  
Solder Joint ◽  
Electric Current ◽  
Ball Grid Array ◽  
Current Effect ◽  
Electric Current Effect

Electric Current Effect on Metal Surface Layers

1989 ◽  
Vol 151 (1) ◽  
pp. 121-126 ◽  
Author(s):  
A. M. Roshchupkin ◽  
I. L. Bataronov ◽  
O. A. Troitskii ◽  
M. M. Moiseenko
Keyword(s):  
Electric Current ◽  
Metal Surface ◽  
Current Effect ◽  
Surface Layers ◽  
Electric Current Effect

scholarly journals Experimental evaluation of pulse electric current effect on residual stresses in composite-to-copper joints

2008 ◽  
Vol 40 (4) ◽  
pp. 452-457 ◽  
Author(s):  
G. V. Stepanov ◽  
A. I. Babutskii ◽  
I. A. Mameev ◽  
M. Ferraris ◽  
V. Casalegno ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Electric Current ◽  
Experimental Evaluation ◽  
Current Effect ◽  
Pulse Electric Current ◽  
Pulse Electric ◽  
Electric Current Effect

ELECTRIC CURRENT EFFECT ON YBa2Cu3O6.5+δ CERAMICS PROPERTIES AND COMPOSITION

1991 ◽  
Vol 05 (14n15) ◽  
pp. 1019-1024 ◽  
Author(s):  
V. I. NEFEDOV ◽  
A. N. SOKOLOV ◽  
N. K. BELSKY ◽  
L. I. OCHERTYANOVA ◽  
A. V. FILATOV ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Critical Current Density ◽  
Electric Current ◽  
Critical Current ◽  
Current Density ◽  
Sample Length ◽  
Current Effect ◽  
Electrode Polarity ◽  
First Time ◽  
Electric Current Effect

The changes of the YBa 2 Cu 3 O 6.5+δ properties and composition caused by dc and ac treatments at 77 K have been studied. Considerable changes of the cations and oxygen concentrations due to dc effect have been observed for the first time. Elements have been found to migrate both along the sample length according to the electrode polarity and between the sample bulk and the surface. Small impurities such as S, Si, K and Cl have been observed to migrate along the sample length as well. The composition variations are accompanied by changes of magnetic properties and intragrain critical current density. Some aspects of HTSC degradation under these conditions are discussed.

Ball Grid Array (BGA) Solder Joint Intermittency Detection: SJ BIST

2008 ◽  
Author(s):  
James P. Hofmeister ◽  
Pradeep Lall ◽  
Dhananjay Panchagade ◽  
Norman N. Roth ◽  
Terry A. Tracy ◽  
...  
Keyword(s):  
Solder Joint ◽  
Ball Grid Array

Elevated Stand-Off Heights in Solder Joint Interconnections of Surface Mounted IC Packages Result in Appreciable Stress and Warpage Relief

2018 ◽  
Vol 2018 (1) ◽  
pp. 000534-000542
Author(s):  
Ephraim Suhir ◽  
Sung Yi ◽  
Jennie S. Hwang ◽  
R. Ghaffarian
Keyword(s):  
Solder Joint ◽  
Solder Joints ◽  
Calculated Data ◽  
Ball Grid Array ◽  
Substantial Improvement ◽  
Stress Model ◽  
Solder Material ◽  
The Difference ◽  
Free Solder ◽  
Ic Package

Abstract The “head-in-pillow” (HnP) defects in lead-free solder joint interconnections of IC packages with conventional (small) stand-off heights of the solder joints, and particularly in packages with fine pitches, are attributed by many electronic material scientists to the three major causes: 1) attributes of the manufacturing process, 2) solder material properties and 3)design-related issues. The latter are thought to be caused primarily by elevated stresses in the solder material, as well as by the excessive warpage of the PCB-package assembly and particularly to the differences in the thermally induced curvatures of the PCB and the package. In this analysis the stress-and-warpage issue is addressed using an analytical predictive stress model. This model is a modification and an extension of the model developed back in 1980-s by the first author. It is assumed that it is the difference in the post-fabrication deflections of the PCB-package assembly that is the root cause of the solder materials failures and particularly and perhaps the HnP defects. The calculated data based on the developed analytical thermal stress model suggest that the replacement of the conventional ball-grid-array (BGA) designs with designs characterized by elevated stand-off heights of the solder joints could result in significant stress and warpage relief and, hopefully, in a lower propensity of the IC package to HnP defects as well. The general concepts are illustrated by a numerical example, in which the responses to the change in temperature of a conventional design referred to as ball-grid-array (BGA) and a design with solder joints with elevated stand-off heights referred to as column-grid-array (CGA) are compared. The computed data indicated that the effective stress in the solder material is relieved by about 40% and the difference between the maximum deflections of the PCB and the package is reduced by about 60%, when the BGA design is replaced by a CGA system. Although no proof that the use of solder joints with elevated stand-off heights will lessen the package propensity to the HnP defects is provided, the authors think that there is a reason to believe that the application of solder joints with elevated stand-off heights could result in a substantial improvement in the general IC package performance, including, perhaps, its propensity to HnP defects.

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