An Examination of Failure Theories with Literature Data

An Examination of Failure Theories with Literature Data 

It should be noted that this procedure is very similar to that faced by the analyst. Typically, the analyst s company conducts a limited number of part-on-board solder joint tests. The analyst must then produce predictions for new parts or for design changes with the aid of these test results. Correlation between the model predictions and failure data lends credibility to the analyst s work. 

Despite the prevalence of solders in PCB assembly, no consensus exists as to the proper failure theory for Sn-Pb solder, let alone for lead-free solders. Simple plasticity- and creep-based fatigue life failure models, are considered here  

Refined solder ball(s) Elements Relative solution time Max creep shear strain Solder ball predicted to fail  

In addition to the 256 PBGA model shown in Fig. 10, Fig. 18 to 20 present the other models used in the analysis. While Fig. 18 specifically represents the 937 Input/Output CBGA with a 2.4 nun (0.09 in.) substrate thickness, the other CBGA models differ in the number of solder 

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