A Green Conformable Thermoformed Printed Circuit Board Sourced from Renewable Materials

Area of Science:

• Materials Science
• Sustainable Engineering
• Polymer Science

Background:

• Printed circuit boards (PCBs) are essential for electronic devices, with FR4 being the standard substrate.
• FR4, a glass-fiber-reinforced epoxy resin, lacks sustainability and contributes to electronic waste.
• There is a critical need for eco-friendly PCB substrates that are biodegradable or compostable.

Purpose of the Study:

• To develop and characterize a novel, compostable PCB substrate as a sustainable alternative to FR4.
• To evaluate the substrate's suitability for additive printing of conductive inks and component integration.
• To demonstrate the potential of this green substrate in reducing environmental impact from electronic waste.

Main Methods:

• Developed a PCB substrate using poly(lactic acid) and cotton fabric via compression molding.
• Characterized substrate morphology, wettability (water contact angle), and dielectric properties.
• Assessed thermoforming capabilities and suitability for microdrilling.
• Printed conductive silver ink and assembled a functional circuit with LEDs.

Main Results:

• The poly(lactic acid)-cotton fabric substrate exhibits comparable dielectric properties to FR4.
• Its surface morphology and wettability (water contact angle of 72°) are suitable for additive silver ink printing.
• The substrate can be thermoformed into curved shapes without compromising conductivity.
• A proof-of-principle circuit demonstrated the substrate's functionality for electronic component integration.

Conclusions:

• The developed compostable PCB substrate offers a viable, sustainable alternative to conventional FR4.
• This innovation can significantly contribute to reducing the environmental burden of electronic waste.
• The material's properties support key PCB manufacturing processes and functional circuit implementation.