560
Y. Wang et al.
Fig. 17.32 Failure analyses of two samples for: (a), (b) thin process up-stream; (c), (d) thin process
down-stream; (e), (f) thick process up-stream and (g), (h) thick process downstream [60]
17.5.5 System Level Weak-Link Failure in 2.5D Integrated
Circuits
In system level EM test of 2.5D integrated circuits, a new failure mode due to synergistic effect of Joule heating and EM has been found [24]. In the test circuit, there are
three levels of solder joints, two Si chips (one of them serves as interposer and has
through-Si-vias), and one polymer substrate. In addition, there are two redistribution
layers; one between every two levels of the solder joints. It has been found that the
redistribution layer (RDL) between the flip chip solder joints and micro-bumps is the
Y. Wang et al.
Fig. 17.32 Failure analyses of two samples for: (a), (b) thin process up-stream; (c), (d) thin process
down-stream; (e), (f) thick process up-stream and (g), (h) thick process downstream [60]
17.5.5 System Level Weak-Link Failure in 2.5D Integrated
Circuits
In system level EM test of 2.5D integrated circuits, a new failure mode due to synergistic effect of Joule heating and EM has been found [24]. In the test circuit, there are
three levels of solder joints, two Si chips (one of them serves as interposer and has
through-Si-vias), and one polymer substrate. In addition, there are two redistribution
layers; one between every two levels of the solder joints. It has been found that the
redistribution layer (RDL) between the flip chip solder joints and micro-bumps is the