Printed circuit boards (PCBs) have come a long way over the years. Electronics design engineers must stay aware of the latest developments to understand how they might soon incorporate them into their work.
For instance, as more products require PCBs and the demand continues rising, so have concerns about reducing e-waste. Fortunately, promising ideas have recently emerged, showing the exciting possibilities.
Biodegradable substrates
Some people take inspiration from nature when figuring out how to reduce waste. That was the case for a university team that uses leaves’ natural structure to create biodegradable substrates that could change PCB designs.
Conventional PCB substrates contain glass fiber-reinforced epoxy resin. They are typically not recyclable, making people eager to find a more sustainable solution. These researchers discovered it through quasi-fractal lignocellulose structures, which act as scaffolds for leaves’ living cells. The group realized they could also bind solution-processable polymers. Tests showed this alternative can tolerate soldered circuitry manufacturing and supports innovative thin-film devices.
Additionally, once the PCB substrate is no longer usable, users can sustainably dispose it by allowing it to break down in soil or processing the component in biogas plants to recover some of its precious metals for reuse.
In another effort to tackle e-waste, researchers developed a PCB that people can recycle several times with virtually no material loss. Their experiment showed it performed as well as those made from traditional materials.
The group developed a solvent that turns a class of sustainable polymers into a jelly-like substance without harming the solid components left behind. Users can then pick them out for recycling. This approach allows them to recover 98% of the polymers, 91% of the recycling solvent, and all the glass fiber.
Moving ahead with flexible PCBs
Electronics designers and others are also interested in moving away from rigid PCBs and prioritizing flexible ones when possible. This improvement enables better application versatility and helps users produce smaller, more complex devices.
Next, mechanical engineers have developed a pioneering way to create the circuits necessary for electronic connections inside devices from wearable health trackers to robots. Those working on this project believe progress with soft circuits could revolutionize how engineers use and create electronic devices. Additionally, currently available flexible PCBs require few or no wires, reducing connection failures.
This team created a production process that uses liquid-metal microdroplets to make a stair-like structure when adding vias and planar interconnects. The method allows them to enable electrical connections across layers without physically drilling into the material, as previous options required.
Experiments suggested engineers could use the microdroplet application technique on several materials or build multiple layers to suit individual device specifications. This method is also efficient; researchers were able to make several vias in less than a minute. In one case, they made a dual-layer soft circuit with nine LEDs on the top and nine connected sensors on the bottom. This component had 21 liquid-metal connectors and was only as thick as a sheet of paper.
PCBs will continue evolving
These are some of the many examples of engineers’ ongoing efforts to make PCBs more aligned with today’s devices and the industry’s priorities. Electronics design engineers should remain aware of these innovations and continually explore how they might implement these possibilities into future projects.
Ellie Gabel is a freelance writer as well as an associate editor at Revolutionized.
Related Content
- PCB design basics
- PCB Design Considerations and Tools
- Tool makes high-end PCB design affordable
- Trends and Challenges in PCB Manufacturing
- The history and evolution of printed circuit board (PCB) designs
The post The evolution of PCBs and the demands of modern electronics appeared first on EDN.