Growth kinetics of intermetallic compound in solder joints during thermal cycling: a review

Abstract

A critical review is made in this paper to summarize the recently published studies about the growth kinetics of intermetallic compound (IMC) in solderjoints during thermal cycling in the applications of electronic packaging structures. The kinetics model based on diffusion mechanism has been well investigated for description of IMC growth at the solder and substrate interface under a constant high temperature. However, in the service condition, packaging structures are usually under varying temperature and the induced force due to the CTE mismatch between different material layers. In light of the fact that the mechanical properties of solderjoints are strongly affected by the IMC morphology, the coupled effects of stress and temperature on the growth of both the interfacial and isolated IMCs should be taken into account. In the literature, the published works regarding interfacial IMC growth kinetics can be classified into three categories: constant temperature, varying temperature with equivalent time and the couple effect of constant stress and temperature. The merits and demerits of these three categories are discussed from the solder joint mechanical reliability point of view. Meanwhile, the diffusion study regarding the isolated IMC morphology in the solid state is rare and some brief discussions are made to expect intensive investigations in the future.