IGBT Modules - Technologies, Driver and Application (Second Edition) - page 528

Fig. 14.27
Removed layer after bonding
epicts several misplacements of the bond wire.
shows a
"chaotic" arrangement of the bond connections on a diode surface. In
bond foot is not centred on the gate pad, while in
a bonding foot is slightly
protrudingbeyond the copper surface of theDCB.
Fig. 14.28
Misplacement of the bondwire
show examples of failed bond connections in operation. The
first one shows a fracture of the bond wire, the second image shows a detached bond
wire from the chip surface. Both are caused by cyclic stressing of the bond wire or by
load changes of the chipmetallisation.
hows a typical fault pattern caused by mechanical vibration of the module.
Three separate bond wires connected in parallel were dislodged in succession by the
vibration. The remaining bondwire, which then had to take over the entire load current,
melted likea fuse.
Fig. 14.29
Damage from vibration
1...,518,519,520,521,522,523,524,525,526,527 529,530,531,532,533,534,535,536,537,538,...548
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