Influences of storage conditions on component cracking

摘要

The increasing miniaturisation in electronics production withsimultaneous increase in functionality leads to finer structures andlarger chip-size high pin count components. The enlargement of thecomponent size increases the danger of component damage due to moistureabsorption. To avoid potential component failure through tears at thecompound or through subsequent corrosion, these cracking-endangeredcomponents are delivered in specific containers, drypacks, and arestored in nitrogen set. Furthermore, the user normally retests thecomponents before releasing them in a series of destructive, cost- andtime-consuming tests. Despite these extensive measures, components oftenfail during reflow soldering but are mostly recognised later, duringuse. The existing damage model describes the connection between storageconditions and its effects with component quality during processinginadequately. In this paper, the influence of different storageconditions on cracking behaviour of high pin count components isexamined. The aim is to register all relevant influential parameters inan expanded damage model and to quantify effects on later processing ofthe components. Effective strategies can be developed based on the newdamage model for component storage and transportation. It was validatedthat over a component-specific relative longitudinal change (approx.3%), cracking is registered. Whether this limit is exceeded depends onthe maximum soldering temperature, the moisture absorbed by thecomponent, its general tensile stress behaviour and the heating rate