System Operating Environment Effect on PCB Material Electrical Property

The purpose of this paper is to consider the impact of humidity and temperature on the electrical properties of printed circuit boards ( PCBs). PCB base materials are glass reinforced thermosetting laminates using a variety of resin systems with different loss characteristics. Test results indicate humidity has little impact on electrical properties of inner layer. It is difficult for moisture to penetrate into the PCB due to barriers created by copper ground planes. Conversely, temperature has a significant influence on PCB's electrical properties. Increasing temperature from 20 to 80 degrees C has a limited impact on dielectric constant (< 3%) for all material types: standard loss, middle loss, low loss and ultra-low loss materials. The impact of increased temperature, 20 to 80 degrees, on loss tangent is more significant. Increasing temperature from 20 to 80 degrees C will influence loss tangent according to material type ranging from 10.4% for ultra-low loss to 38.7% for standard loss materials.