Thermal and RF Characterization of Novel PLA/Flax Based Biodegradable Printed Circuit Boards

Abstract

In this study, a novel printed circuit board (PCB) substrate made of polylactic acid (PLA) reinforced with flame-retarted flax fibers is presented as a biodegradable substitute for conventional PCB materials, which is compatible with traditional subtractive technology and SMT assembling, so that the present and future trends in green electronics could fit in the well-established packaging processes. The current paper focuses on thermal and RF characterization of the materials, with the addition of environmental analysis based on pilot antennas. Finally new promising path for improved quality is presented. It was found that the thermal diffusivity of the material mainly depends on the PLA in the composite, where the values are in good agreement with the ones that can be found in the literature regarding the base material. The RF characterization shows, that the RF losses are better than paper-based substrates. The paper reveals that from the aspect of environmental impact, such assemblies can be considered better than ones manufactured from traditional substrates, but worse than e.g. paper-based electronics. The paper also reveals a future path with a promising new generation of the PLA/flax boards, leading to similar build qualities as on traditional FR4 boards.