Environmental impacts of printed electronics and challenging electronic waste

Abstract

Waste electrical and electronic equipment (WEEE) is the fastest-growing waste stream. This dissertation study the environmental impacts of printed electronics and challenging electronic waste. The environmental impacts on production and end-of-life stages of printed electronics are assessed as well as the environmental impacts of waste management of plastics in electronic waste.

The primary objective of this research is to offer decision-makers and product developers with insights into the environmental impacts of printed electronics and plastics in WEEE. The potential challenges in waste management are also addressed.

This dissertation is prepared based on three research articles and a literature review to address the following questions: ‘Which processes are the main contributors to the environmental impacts of producing conventional printed circuit board (PCB) and printed electronics (PE)? What are the solutions to mitigate the environmental impacts of PE manufacturing? What is the most environmentally friendly solution to manage the plastics in WEEE? What are the possible challenges of treating the PE at the end-of-life stage?’

The goals of this dissertation were achieved by using life cycle assessment (LCA) and scientific literature review (SLR) methods to evaluate environmental performance and impacts throughout the life cycle. Three articles use LCA, focusing on Finland, while one article uses SLR methodology to explore the field.

The study found that electricity and chemicals are the key contributors to the global warming potential (GWP) of conventional PCBs, while metal conductors such as silver or copper microparticles dominate the GWP when electronic boards are printed on paper, PET, and PLA. Transitioning to additive manufacturing and increasing metal recycling can significantly reduce the environmental footprint of PCB production. Printed electronics can replace conventional PCBs in some cases, but they remain limited in applications where durability and long-lasting performance are required.

The study also reviewed plastic waste recovery methods, particularly for electronic waste (WEEE), which is more difficult to recycle due to mixed materials like bromine flame retardants. Mechanical recycling of bromine-free polymers from WEEE offers environmental benefits in GWP impact category compared to incineration or chemical recycling. Mechanical recycling with plastic separation (MRS) has lower environmental impacts than other methods. For mixed WEEE, where separation is not possible, composite mechanical recovery (MRC) and chemical recovery (CR) are better options than energy recovery (ER).

The dissertation shows that printed electronics are often disposed in the same waste stream as their packaging, and current recycling systems typically incinerate or landfill the metal parts. As printed electronics develop, designers need to focus on separation and recycling to reduce waste and maximize material reuse. Using non-metallic inks like graphene could help improve recyclability. Careful planning is needed to ensure printed electronics offer environmental, economic, and commercial benefits.