A Two-Body Formulation for Solder Joint Shape Prediction

1998 ◽  
Vol 120 (3) ◽  
pp. 302-308 ◽  
Author(s):  
F. P. Renken ◽  
G. Subbarayan
Keyword(s):  
Solder Joint ◽  
Surface Area ◽  
Flip Chip ◽  
Contact Angles ◽  
Sessile Droplet ◽  
Solution Approach ◽  
Shape Prediction ◽  
Body Formulation ◽  
Wetted Surface Area ◽  
Joint Shape

Solder shape prediction is essential for accurate fatigue life determination and joint design optimization. In the present paper, a new solution approach using the surface tension theory is developed to simultaneously predict standoff height, wetted surface area, contact angles, and solder shape by including energy effects between a molten solder body and an arbitrarily shaped solid body. Existing models for solder shape prediction do not appear to determine all characteristics including joint standoff height, wetted surface area, and contact angles simultaneously. A general two-body axisymmetric finite element code is developed and coupled with a constrained optimizer to solve four illustrative examples. These examples include the shape of a sessile droplet on a fixed pad, a flip-chip joint, a sessile droplet on a free surface, and a typical ceramic ball grid array solder joint. In all four examples, the results predicted by the present approach compare favorably with available experimental and numerical results.

Electronic Packaging Reflow Shape Prediction for the Solder Mask Defined Ball Grid Array

1998 ◽  
Vol 120 (2) ◽  
pp. 175-178 ◽  
Author(s):  
K.-N. Chiang ◽  
W.-L. Chen
Keyword(s):  
Solder Joint ◽  
Electronic Packaging ◽  
Engineering Application ◽  
Contact Angles ◽  
Joint Models ◽  
Surface Evolver ◽  
Minimization Principle ◽  
Shape Prediction ◽  
Fine Pitch ◽  
Practical Engineering

The increasing need to create high density and fine pitch electronic interconnections presents a number of challenges. The fatigue-induced solder joint failure of surface mounted electronic devices has become one of the most critical reliability issues in electronic packaging industry. Prediction of the shape of solder joint has drawn special attention in the development of electronic packaging for its practical engineering application. Many solder joint models have been developed based on energy minimization principle (Patra et al., 1995) or analytical method (Heinrich et al., 1993; Liedtke 1993). These methods are extensively utilized to the shape design of solder joint. However, it is important to find a suitable method in real application. In this study, an efficient numerical method used to predict the shapes of solder joint is investigated, and the results are compared with Surface Evolver program (Brakke, 1994). The changes of geometric shape with respect to different parameters of solder joint are also discussed in this paper. The influences of the geometric parameters, such as volumes of solder joint, package weight, contact angles, pads sizes, solder surface tension, and gravity forces to the shape of solder joint, are investigated. Results presented in this study can be used to determined the optimally balanced stand-off height of single ball module (SBM) or multiple ball module (MBM) solder joint models.

Solder Joint Formation in Surface Mount Technology—Part I: Analysis

1990 ◽  
Vol 112 (3) ◽  
pp. 210-218 ◽  
Author(s):  
S. M. Heinrich ◽  
A. F. Elkouh ◽  
N. J. Nigro ◽  
Ping S. Lee
Keyword(s):  
Solder Joint ◽  
Laboratory Data ◽  
Integral Form ◽  
Contact Angles ◽  
Reflow Process ◽  
Cross Sectional ◽  
Joint Formation ◽  
Surface Mount ◽  
Theoretical Predictions ◽  
Joint Shape

An analytical model of solder joint formation during a surface mount reflow process is developed in the present paper, and the solution is obtained in an explicit integral form. For two limiting cases—infinitesimal and infinite solder areas—the solution is expressed in closed form. Numerical results illustrate the influence of the process parameters (surface tension, density, and cross-sectional area of the molten solder, and the contact angles between the solder andpretinning) on joint shape and overall fillet dimensions. Comparisons between theoretical predictions and laboratory data show excellent agreement.

A Procedure for Automated Shape and Life Prediction in Flip-Chip and BGA Solder Joints

1996 ◽  
Vol 118 (3) ◽  
pp. 127-133 ◽  
Author(s):  
G. Subbarayan
Keyword(s):  
Finite Element ◽  
Solder Joint ◽  
Life Prediction ◽  
Flip Chip ◽  
Solder Joints ◽  
Three Dimensional ◽  
Reliability Estimation ◽  
Element Mesh ◽  
Shape Prediction ◽  
Dimensional Finite Element

In this paper, a three-dimensional shape prediction model and a finite element solution procedure for flip-chip and BGA solder joints are developed. The developed system is capable of calculating the solder joint geometry and the fatigue life automatically without any intervention from the user. The automation achieved will enable fast reliability estimation and improved accuracy, since the two-dimensional finite element mesh used for solder shape prediction is used to generate the three-dimensional finite element mesh for stress analysis. The implementation of the procedure is verified using the solution for a flip-chip joint from literature, and the capability of the code is demonstrated on a hypothetical three-dimensional solder joint with square pads that are rotated with respect to each other, and offset from each other. The system developed in the study represents the first instance of an integrated, automated finite element procedure for both shape and fatigue life prediction in general three-dimensional solder joints. The automation achieved in the system enables fast reliability estimation in a design environment, and the optimal design of flip-chip and BGA solder joint configurations for maximum life.

Solder Joint Shape Prediction Using a Modified Perzyna Viscoplastic Model

2004 ◽  
Vol 127 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Mudasir Ahmad ◽  
Ken Hubbard ◽  
Mason Hu
Keyword(s):  
Surface Tension ◽  
Numerical Model ◽  
Solder Joint ◽  
Solder Joints ◽  
Element Analysis ◽  
Closed Form Solutions ◽  
Joint Construction ◽  
Shape Prediction ◽  
Applied Forces ◽  
Joint Shape

Ball grid array solder joint reliability is known to be dependent on the shape of solder joints after reflow. To ensure good solder joint formation and prevent solder bridging, it is critical to understand the amount of paste volume needed during assembly and reflow. The final shape of the solder joint is a function of surface tension, wetting area, gravity, and applied forces. In this paper, a new methodology to simulate solder joint shape is presented. Large deformation viscoplastic finite element analysis is used to simulate incompressible fluid flow. A numerical model for surface tension is outlined and validated with closed-form solutions. The results of the numerical model are compared to other known solder joint shape prediction methods. The effects of package weight, coplanarity, warpage, paste volume, pad misregistration, and joint construction on solder joint shape are then analyzed. Recommendations are provided on ways to maximize standoff height and avoid bridging. Finally, the formation of leadless solder joints is studied and compared to experimental data.

Experimental evaluation of SnAgCu solder joint reliability in 100-μm pitch flip-chip assemblies

2014 ◽  
Vol 54 (5) ◽  
pp. 939-944 ◽  
Author(s):  
Ye Tian ◽  
Xi Liu ◽  
Justin Chow ◽  
Yi Ping Wu ◽  
Suresh K. Sitaraman
Keyword(s):  
Solder Joint ◽  
Experimental Evaluation ◽  
Flip Chip ◽  
Solder Joint Reliability ◽  
Snagcu Solder ◽  
Joint Reliability
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