How To Achieve Sustainable PCB Manufacturing and Assembly

How To Achieve Sustainable PCB Manufacturing and Assembly

The constant advancements in smart devices and consumer electronics have increased the level of hazardous electrical and electronic equipment waste globally. Since the proper handling and disposal methods are not implemented consistently, this waste is proving to be a toxic problem that needs immediate attention. Some initiatives have already been introduced to deal with this matter, but they are insufficient. Let’s analyze these current solutions and emerging manufacturing practices to see how it’s possible to achieve sustainable PCB manufacturing and assembly.

Current Solutions for Achieving Sustainable PCB Manufacturing and Assembly

Using Lead-Free Solder

Lead is a toxic heavy metal that is used in solder (mixed with tin) to lower its melting point and form strong joints. But regulatory requirements like RoHS have pushed the industry to switch to more environmentally friendly lead-free solder, which contains metals like copper and silver mixed with tin.

There are some downsides to using lead-free solder. For instance, mining and extracting these new metals for the alloy can have negative environmental impacts. On top of that, these metals introduce inefficiencies in the solder joint, such as reduced thermal fatigue resistance. As such, PCBs built for demanding applications, such as military or aerospace, must be assembled using lead solder.

Implementing Recycling Programs

Recycling programs were introduced to recover valuable PCB materials in electronics that are at the end of their life. These include valuable metals like copper, gold, and silver, which are economically viable to recycle. However, large portions of the board, such as the fiberglass substrate, are not recycled, meaning these programs don’t eliminate the pollution problem wholly. 

Using Halogen-Free Laminates

Halogen laminates are not toxic when used in laminates per se. The toxicity comes in when they burn. Since they are used as flame retardants, halogen laminates release noxious fumes that capture free radicals to slow down or stop combustion if the PCB catches fire. The chlorine, bromine, or fluorine fumes are toxic to humans and the environment, making halogen-free laminates better alternatives.

There is a trade-off though. Nitrogen, phosphorus, and other halogen-free laminate flame retardants are not as heat resistant and strong mechanically, resulting in lower reliability.

Using Environmentally-Friendly Chemical Treatment Technologies

Chemical treatments used in PCB manufacturing, such as cleaning agents and etching acids, have been evaluated over time to make them more eco-friendly. This is done by checking the efficacy of the solution (processing time) vs. its environmental impact.

Emerging Sustainable PCB Manufacturing and Assembly Practices

Using Bio-Based Materials

While some metals used on the PCB can be recycled, the substrate is usually left for landfills. Recent advancements in bio-based materials are making this a non-issue because the substrates used will be biodegradable. Natural polymers like cellulose, silk, lignin, gelatin gels, and GPTE have proven effective at meeting the required electrical and thermal properties for PCBs.

These are coupled with bio-based resins, which provide similar electrical properties to epoxy resins and are almost at par in thermal stability.

Replacing Hazardous Solvents with Green Manufacturing

Instead of using hazardous or mildly toxic chemicals during production, PCB manufacturers are exploring green manufacturing options. These include using supercritical fluids, water-based solutions, and even additive manufacturing methods, such as 3D printing. 3D printing is particularly an interesting field because it enables manufacturers to create complex PCB geometries using green materials.

Adopting Circular Manufacturing Models

Circular manufacturing models boost sustainability by creating a closed-loop system for the materials from as early as PCB design. During this phase, design engineers lay out circuit boards that are easy to dismantle at the end of their life cycle to simplify material recycling or reuse. They can also design PCBs that can be upgraded easily to eliminate the need for full replacements.

But replacements can’t be fully avoided. So part of the circular manufacturing model includes partnerships with PCB recycling facilities to create a responsible and sustainable circular model.

Adopting Life Cycle Assessment Practices

Adopting a circular manufacturing model shouldn’t be the end of it. PCB manufacturers need to adopt life cycle assessment practices to get a full picture of the impacts of the green PCB manufacturing model and disposal/recycling. This will help determine the model’s effectiveness and inform any necessary changes that will help further reduce their environmental impact.

Wrapping Up

The sustainable PCB manufacturing ecosystem is in a delicate state that requires a careful balance between performance, environmental responsibility, and cost. While the current solutions are effective, they don’t address the environmental-responsibility factor fully. On the other hand, the emerging solutions look promising on the environmental front, but they might affect the performance and cost factors.

So sustainable PCB manufacturing still needs a lot of research to determine the best solutions, and some of the manufacturers at the forefront of this are OurPCB and WellPCB. If you would like to learn more about their sustainable PCB and PCBA production practices or get your circuit board fabricated and assembled in an eco-friendly manner, contact them for more details.