Influences of organic materials on packaging technologies and their consideration for lifetime evaluation

In the recent years the number of applications using organic materials has been significantly increased for electronic devices (e.g. organic LEDs or organic solar cells). This results in stricter requirements to reliable substrate and packaging materials for these applications, especially for flexible substrates. Furthermore, this implies new tasks for the qualifying procedures. One requirement is to characterize the aging of flexible and semiflexible packages concerning bending and twisting. The existing and established test methods have been solely developed for testing rigid substrates and are focused on the influences of the different CTEs (Coefficient of Thermal Expansion) in the electronic package. Adapted mechanical test methods for flexible substrates are not available at the moment. We expect specific damage scenarios which are not characterized with corresponding parameter values. Therefore, we engineered test equipment aiming to accumulate failure data during accelerated aging. These data enable us to develop an aging model for solder joints and comparable technologies. In a subsequent FEM simulation we have to describe a model for different kinds of failure modes. Initial analyses are shown in this paper and shall present an overview on this topic. Furthermore, we investigated a low temperature soldering process for cheap polymeric substrate materials. These materials have a glass transition temperature (T_g) lower than 150°C. The visual appearance is a new topic for electronic packaging, which we have to consider in these investigations.