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78 SMT007 MAGAZINE I AUGUST 2021 and grow as solid phases during the solidifying of solders on the interface between the solder alloy and its bonding pads [21] . is ensures reli- able bond strength. Effect of wire misalignment Since both, wire diameter and Ag pad width (in front side of the cell) are minimum, even a slight misalignment will affect the peel strength values [19] . Peel strength of each of the Ag pads on the front and back side was noted and plot- ted. Corresponding microscopic images were taken to see the correlation between wire align- ment on Ag pad and peel strength. e graphi- cal representation of peel strength on front and back side is illustrated in Figure 7. When there is wire misalignment over the Ag pad, peel strength value decreases drastically (1.0 to 1.5 N). In the case of proper wire alignment, peel strength values were high (3.0-3.5 N). us, wire misalignment has a direct impact on peel strength. e peel strength data of the back side of the cell was less affected and relatively constant due to wider silver pads (Figure 8). Other Factors—Cold and Dry Solder Joints Cold or dry joints are weak joints and char- acterized by the absence of bond formation between the wire and pad. Both terms can be interchanged but there is a slight difference. Weak joints are joints having peel strength <1 Figure 7: Peel strength of individual silver pads on the front and effect of wire misalignment. Figure 8: Peel strength of individual silver pads on the back side of the cell.