Experimental investigation on testing conditions of solder ball shear and pull tests and the correlation with board level mechanical drop test

2007 ◽  
Author(s):  
Fubin Song
Keyword(s):  
Experimental Investigation ◽  
Solder Ball ◽  
Drop Test ◽  
Testing Conditions ◽  
Ball Shear ◽  
Pull Tests ◽  
Board Level ◽  
Mechanical Drop Test

Experimental Evaluation on Solder Joint Reliability of PBGA Assembly Under Mechanical Drop Test

2002 ◽  
Author(s):  
Shi-Wei Ricky Lee ◽  
Yin-Lai Tracy Li ◽  
Hoi-Wai Ben Lui
Keyword(s):  
Solder Joint ◽  
Failure Modes ◽  
Solder Joints ◽  
Drop Test ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
Free Solder ◽  
Board Level ◽  
Better Than ◽  
Mechanical Drop Test

The present study is intended to investigate the board level solder joint reliability of PBGA assemblies under mechanical drop test. During the course of this study, a five-leg experiment was designed to investigate various combinations of solder materials and peak reflow temperatures. Two major failure modes, namely, solder cracking and copper trace breakage, were identified. In addition, the critical location of solder joints was characterized. It was found that Sn-Pb eutectic solder joints performed better than Pb-free solder joints under mechanical impact loading.

scholarly journals Effect of Structural Design Parameters on Wafer Level CSP Ball Shear Strength and Their Influence on Accelerated Thermal Cycling Reliability

2009 ◽  
Author(s):  
Nikhil Lakhkar ◽  
Puligandla Viswanadham ◽  
Dereje Agonafer
Keyword(s):  
Thermal Cycling ◽  
Shear Test ◽  
Solder Ball ◽  
Wafer Level ◽  
Ball Shear ◽  
Ball Size ◽  
Ball Shear Test ◽  
Accelerated Thermal Cycling ◽  
Ball Shear Strength ◽  
Board Level

Ball shear testing is typically conducted in Wafer level chip scale package (WLCSP) fabrication to estimate the strength of the solder ball attachment. Generally, the solder ball shear strength is dependent on the solder ball size, pad size, solder/pad interface treatment, reflow temperature and time. Solder ball strength is also a function of ram speed and height at which the ball is sheared with respect to the wafer. Recent investigations suggest that ball shear test is being used as an indicator for board level reliability of assemblies. In current market lead time for launching a new product is very short. Unfortunately, it takes several weeks to qualify a new product by board level qualification process. If there is a methodology through which one can predict the board level performance by extrapolating the wafer level test, it will save great amount of resources in testing and millions of dollars worth of testing time. In the first part of this study, we conducted a wafer level ball shear test. A DOE was created for varying wafer level structural parameters like solder ball size and type. Ball shear tests and Accelerated thermal cycling have similar failure signatures of compression on inner side and tension on outer side. Thus, for specific cases there is a possibility of correlating the two failure methodologies based on their failure signatures. Strain rate for ball shear test was determined based on shear speed and solder pad diameter. Strain rate for accelerated thermal cycling was determined based on difference in CTE between board and package. In this paper, results from ball shear test and accelerated thermal cycling are compared to find correlations for specific cases. The correlations derived from this study are statistical and empirical.

The Effect of Ball Pad Metallurgy and Ball Composition on Solder Ball Integrity of Plastic Ball Grid Array Packages

1998 ◽  
Author(s):  
C.H. Zhong ◽  
Sung Yi
Keyword(s):  
Failure Mode ◽  
Barrier Layer ◽  
Shear Force ◽  
Solder Ball ◽  
Ball Grid Array ◽  
Reliability Test ◽  
Shear Forces ◽  
Ball Shear ◽  
Plastic Ball ◽  
Plastic Ball Grid Array

Abstract Ball shear forces of plastic ball grid array (PBGA) packages are found to decrease after reliability test. Packages with different ball pad metallurgy form different intermetallic compounds (IMC) thus ball shear forces and failure modes are different. The characteristic and dynamic process of IMC formed are decided by ball pad metallurgy which includes Ni barrier layer and Au layer thickness. Solder ball composition also affects IMC formation dynamic process. There is basically no difference in ball shear force and failure mode for packages with different under ball pad metallurgy before reliability test. However shear force decreased and failure mode changed after reliability test, especially when packages exposed to high temperature. Major difference in ball shear force and failure mode was found for ball pad metallurgy of Ni barrier layer including Ni-P, pure Ni and Ni-Co. Solder ball composition was found to affect the IMC formation rate.

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