The Kirkendall effect is a well-known phenomenon resulting from the difference in intrinsic diffusivities of chemical constituents of substitution solid solutions (non-reciprocal diffusion).
How do you analyze Kirkendall effect diffusion?
This chemical diffusion coefficient can be used to mathematically analyze Kirkendall effect diffusion via the Boltzmann-Matano method . One important consideration deriving from Kirkendall’s work is the presence of pores formed during diffusion.
What is the marker in the Kirkendall experiment?
The Kirkendall experiment requires a diffusion couple with a small inert marker located within the diffusion zone between the two involved migrating atomic species. An illustration of what happens to the marker during thin-film silicide formation is shown in Fig. 11-25.
What is the Kirkendall effect in wire bonding technology?
His paper demonstrated the importance of the Kirkendall effect in wire bonding technology, but also showed the significant contribution of any impurities present to the rate at which precipitation occurred at the wire bonds.
The Kirkendall effect arises when two distinct materials are placed next to each other and diffusion is allowed to take place between them. In general, the diffusion coefficients of the two materials in each other are not the same.
What are the common causes of wire bond failure?
Common causes of wire bond failures include the following: Atomic interdiffusion between different metals is a natural phenomenon in a wirebond metallurgical system. If left unchecked, however, this can lead to voids in the bond that can result in significant degradation of the bond’s mechanical strength and electrical conductivity.
What causes the bond pads to corrode?
The presence of halogen contaminants on the bond pads can cause the bond pads to corrode in the presence of moisture. Corrosion per se is a major cause of bond failure as the bond and wire are eaten away.
