Implementation of microcontroller board on a sustainable and degradable PLA/flax composite substrate: a case study

Area of Science:

• Materials Science
• Electronics Engineering
• Environmental Science

Background:

• The microelectronics sector faces significant e-waste challenges.
• Traditional Flame Retardant Class 4 (FR4) substrates contribute to environmental pollution.
• There is a growing need for sustainable and biodegradable materials in electronics.

Purpose of the Study:

• To develop and demonstrate a novel biodegradable polylactic-acid/flax-composite substrate for printed circuit board (PCB) applications.
• To assess the feasibility of using natural, bio-based materials as a sustainable alternative to FR4.
• To evaluate the performance and limitations of the novel substrate in a functional microcontroller board.

Main Methods:

• Fabrication of a copper-clad polylactic-acid/flax pre-preg.
• Implementation of a demonstrator microcontroller board based on the Arduino Nano design.
• Processing using subtractive printed wiring technology and surface mounting assembly.
• Performance evaluation through signal analysis and Highly Accelerated Stress Testing (HAST).

Main Results:

• A functional microcontroller board was successfully created on the novel biodegradable substrate.
• PCB production yield was approximately 50%, with successful low-frequency signal analysis comparable to FR4.
• HAST revealed significant limitations: ~30% weight loss and an 80% reduction in ultimate strength after stress tests.

Conclusions:

• The polylactic-acid/flax composite offers a highly sustainable alternative, potentially substituting ~95 vol% and ~90 wt% of traditional substrate materials.
• While demonstrating proof-of-concept, the material requires further development to improve its mechanical strength and durability for widespread adoption.
• This research paves the way for more environmentally friendly electronics manufacturing, addressing e-waste concerns.