• Vreugd, J. De
• Bohm, C.
• Jansen, Kaspar
• Ernst, Lj

Abstract

Reliability and functionality of microelectronic devices is highly influenced by their packaging material. For reliable predictions of stresses in microelectronics, properties of the packaging material have to be known. In this work the moisture absorption and desorption characteristics of epoxy molding compound is investigated by making use of accurate sorption equipment. It is found that the diffusion coefficient is dependent on humidity level. Moisture induced swelling is measured by making use of a DMA at which a humidity generator is connected. By clamping a sample strip in the DMA and applying a humidity step, the sample will deform. This deformation is measured by the DMA and is recalculated to a strain. In this way, moisture absorption experiments could be done at different temperature and humidity levels. It is found that the swelling coefficient is increasing at higher temperatures. Results of both absorption and moisture induced swelling experiments are modeled by modifying Fick's law. Finally creep experiments are performed in order to measure the mechanical behavior of molding compounds at different temperature and relative humidity levels. These results and the obtained models are discussed in this paper.Index terms-Creep measurements, hygroscopic swelling, moisture absorption, viscoelasticity.

Topics

• impedance spectroscopy
• compound
• experiment
• viscoelasticity
• creep