Enhanced Polymer Passivation Layer for Wafer Level Chip Scale ...

Figure 5.2 Global model with a submodel ............................................................................... 97
Figure 5.3 Slice model .............................................................................................................. 98
Figure 5.4 Comparison of Creep Models for SnAgCu and SnPb solder .................................. 103
Figure 5.5 Schemiatic representation of the standard (a) and solderbrace-coated
(b)WLCSP assembly (not to scale) ........................................................................ 108
Figure 5.6 The diagonal symmetry model ............................................................................. 109
Figure 5.7 Finished mesh for the solderbrace-coated WLCSP package ................................. 112
Figure 5.8 Boundary Conditions applied to a typical slice model ......................................... 113
Figure 5.9 Von Mises stress (MPa) distribution in the solder joint for (a) Solderbrace-coated
model and (b) Reference (non-coating) model ..................................................... 116
Figure 5.10 Air-to-air thermal cycling reliability test results ................................................ 116
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