Thermally Induced Delamination Buckling of a Thin Metal Layer on a Ceramic Substrate

Abstract

Interface delamination failure caused by thermomechanical loading and mismatch of thermal expansion coefficients and other material properties is one of the important failure modes occurring in electronic packages, thus a threat for package reliability. To solve this problem, both academic institutions and industry have been spending tremendous research effort in order to understand the inherent failure mechanisms and to develop advanced and reliable experimental and simulation methodologies, thus to be able to predict and to avoid interface delamination before physical prototyping. Various damage mechanisms can be involved and can result in interface delamination phenomena. These are not all sufficiently addressed and/or reported so far, probably because of the complexities caused by the occurrence of strong geometric and materials nonlinearities. One of the phenomena being insufficiently understood so far is the so-called buckling-driven delamination of thin metalic layers on ceramic substrates. This phenomenon will be discussed in the present paper.

Thermally actuated buckling beam memory: a non-volatile memory configuration for extreme space exploration environments

“…When the beam is manufactured in the absence of external loadings, it may remain in an unbuckled configuration, as shown in (a). Unless extreme care is taken to minimize thermal stresses and other loadings during manufacturing (Liu et al 2003;Martin et al 2007) the beam will either buckle upwards, in the positive z-direction, as shown in (c), or downwards, in the negative z direction, as shown in (b). Because of the bistability of the system, the beam remains in the buckled position after the load is removed.…”

“…Thermal buckling, where the beams are buckled through the creation of thermal stresses in the structure, is a viable alternative actuation method (Chiao and Lin 2000). While thermal buckling is often an undesirable artifact of thermal stress build-up during micro-fabrication (Liu et al 2003;Martin et al 2007), it is also an effect that can be exploited in device actuation (Chiao and Lin 2000;Laws et al 2008;Arya et al 2006;Matoba et al 1994).…”