Influences of storage conditions on component cracking

Abstract

The increasing miniaturisation in electronics production with simultaneous increase in functionality leads to finer structures and larger chip-size high pin count components. The enlargement of the component size increases the danger of component damage due to moisture absorption. To avoid potential component failure through tears at the compound or through subsequent corrosion, these cracking-endangered components are delivered in specific containers, drypacks, and are stored in nitrogen set. Furthermore, the user normally retests the components before releasing them in a series of destructive, cost- and time-consuming tests. Despite these extensive measures, components often fail during reflow soldering but are mostly recognised later, during use. The existing damage model describes the connection between storage conditions and its effects with component quality during processing inadequately. In this paper, the influence of different storage conditions on cracking behaviour of high pin count components is examined. The aim is to register all relevant influential parameters in an expanded damage model and to quantify effects on later processing of the components. Effective strategies can be developed based on the new damage model for component storage and transportation. It was validated that over a component-specific relative longitudinal change (approx. 3%), cracking is registered. Whether this limit is exceeded depends on the maximum soldering temperature, the moisture absorbed by the component, its general tensile stress behaviour and the heating rate.