Figure 5 shows EDX Mapping images of bus bars printed of paste composition with the glass frit content of
point X and Y in figure 4. Figure 5a 5c confirm the optimum glass frit composition for paste X, resulting in a
homogeneous glass layer increasing the mechanical contact between bus bar and wafer. This results in high peeloff
forces. Figure 5d 5f indicate an oversupply of glass frit B with paste Y. The glass frit is wetting the metal
surface very well stabilizing the bus bar internally. Figure 5f indicates that the higher content of Frit B also results
in an inhomogeneous glass layer destabilizing the contact between bus bar and silicon. This leads to holes between
metal and silicon. The peel-off force drops.