Effects of latent damage of recrystallization on lead free solder joints

Influence of bismuth on the solidification of Sn-0.7Cu-0.05Ni-xBi/Cu joints

“…Note that this is significantly different to joints made with Ag-containing solders on Cu substrates (e.g. SAC or SnAg solders), where there is usually only a single nucleation event and either single grain, cyclically twinned 'beachball', or interlaced twinned structures [52,[63][64][65][66][67] and no reproducible grain orientation relative to the substrate [68]. In the case of Sn-0.7Cu-0.05Ni-xBi (x≤5) solders, this type of βSn grain texture where the c-axis of the βSn crystal is oriented horizontally might be favourable for retarding electromigration that occurs fastest along the c-direction in the βSn crystal [69,70].…”

Impact of laminate cracks under solder pads on the fatigue lives of ball grid array solder joints

“…In the case of lead-free soldering, there is also another important factor affecting the stress on the solder joints. In contrast to SnPb solder joints, which consist of a large number of tin-rich and lead-rich grains, SAC solder joints to BGAs often consist of only one or a few tin grains [7][8][9][10][11][12]. Exceptions are solder joints with small solder volume [9,12] and lead-free solders based on tin and silver with no copper [11].…”

Thermal Fatigue Reliability Analysis and Structural Optimization Based on a Robust Method for Microelectronics FBGA Packages

“…The most common analysis method is finite element numerical method [11]- [23]. The thermal-stress distribution [11], [12], thermal-mechanical characteristics [13], prediction and assessment of thermal fatigue life and reliability [14]- [17], thermal fatigue damage mechanism, dynamic creep behavior, and the properties of package solder joints under a complex temperature cycle are obtained by FEA [18]- [20]. These studies provided a basis for thermal fatigue reliability analysis and design of a high-density package.…”