Recent developments in sustainable composites for printed circuit boards (PCBs): a review

Today, most of the PCBs used consist of a composite structure made of glass fibre and epoxy material, commonly referred to as FR4. FR4's easy handling during PCB manufacturing, as well as its robustness and electrical properties, have made it an indispensable material for many years. However, the difficulties in the recycling of FR4 and the high CO2 emission during the production process have revealed the necessity of using different materials. Despite the necessity of sustainable PCBs in the electrical and electronic sector, there are no comprehensive reviews highlighting the potential of sustainable PCBs substituting conventional FR4 materials. In this review paper, the development of alternative composites that can be used instead of FR4 in recent years and the benefits they can provide are evaluated and presented. The current review investigates and compares the potential of using natural plant fibers and biodegradable polymers as sustainable key materials in PCBs. The findings highlight that the production of more sustainable PCBs and the reduction of CO2 emissions compared to FR4 are feasible if the correct parameters and manufacturing techniques are used. Finally, this review provides future directions in innovation and sustainable PCBs development, highlighting the need for property enhancement, industrial-academic collaborations.