Effect of Water Absorption on the Low-Frequency Dielectric Properties of Biodegradable PLA/Flax PCB Substrates

The dielectric properties of insulating materials are affected by moisture; hence, applying new PCB substrates requires knowledge of their dielectric behavior under different environmental conditions. This study investigated the dielectric loss of PLA/Flax biodegradable PCB boards in the 500 Hz…500 kHz (low frequency) range. The samples were measured under different environmental conditions, and the absorbed moisture content was determined by weight measurement. The results show that the dissipation factor of the samples increased with absorbed water. Since the measurements were executed at various temperatures, the loss factor increment of the samples is the combination of dipolar loss due to the increased number of water molecules and the increased conductivity of the samples.