Abstract
In the past we conducted experiments to measure the dielectric properties of PCB materials as per industry adopted methods, including preconditioning of test samples. It was observed that some measurement results were not in accordance with manufacturer datasheets. This paper presents follow-up experimental studies on the dependence of dielectric constant and dissipation factor on the moisture content of laminates. Four types of PCB materials from two manufacturers, including two halogen-free and two halogenated, were tested in this study. The paper further establishes whether preconditioning steps outlined in the IPC-TM-650 2.5.5.9 test method account for varying moisture contents in laminate samples.