Research Status of Evolution of Microstructure and Properties of Sn-Based Lead-Free Composite Solder Alloys

Figure 20

The SEM pictures of (a, c) plain Sn-Bi-Ag/Cu and (b, d) Sn-Bi-Ag-0.5Ni/Cu composite solder joints [95].

(a)

(b)

(c)

(d)