PCB Design Tips to Reduce Electronics Waste

I plead guilty to over-pampering my only son. Now 7, he has 2 large boxes of toys that have been idling and gathering dust. It took me two weeks of persuasion, threats and coaxing to finally convinced him that donating the toys to the orphanages is the best choice.  

Unfortunately, the same can’t be said about electronics waste that has been dumped by consumers around the world. With newer gadgets replacing old ones at a rapid pace, people are only eager to discard their devices for newer ones.

As PCB designers, we have a role to play in reducing the impact of electronics waste on the environment and health. And to do that, we need to be clear about the materials that we’re using in the design, the impact it has on the earth and how we can optimize the design to reduce e-waste.

Why Are Electronics Waste Hazardous?

Every single PCB, from the latest smartphone or bulky 40” TV that made it to the landfill harm the environment. While you may be in love with the PCB and components of your latest prototype, they are made of chemicals that lead to various health issues.

Both cadmium and beryllium are found in electronics parts. They are known to cause cancers in humans. Electronics may also contain mercury which can be very toxic even at the slightest exposure. Perhaps a more familiar name will be lead, which his highly toxic especially for toddlers.

The fact that used electronics are discarded and fill up landfills means these chemicals will leak into the environment. They can cause serious pollution to nearby rivers or the air, simply by releasing toxic particles into the surrounding.

Can Electronics Waste Be Recycled?

To a certain extent, electronics waste can be recycled. Gold, copper, and aluminum found within electronics are precious materials that can be reused. However, recycling electronics waste is not a simple process.

There are complicated procedures involved in sorting, cleaning, and size reduction before the useful materials are separated from the non-reusable ones. As electronics contain hazardous chemicals, stringent safety precautions need to be enforced during the recycling process.

Electronics waste recycling is a costly affair. It is only justified when the cost of recovering precious metals like gold is lesser than the cost of mining from the earth. Through proper handling of the toxic residue, recycling will reduce the impact of electronics waste on Earth but is not a perfect solution.

How To Reduce Electronics Waste In PCB Design

With the restriction of hazardous substances (RoHS) compliance, there are restricted hazardous materials for one to avoid in their designs. One place to start with reducing electronics waste is to adhere to and pay careful attention to RoHS compliances. RoHS regulations are designed to limit or eliminate substances that are dangerous to the environment and to people.

You can add to RoHS compliance, WEEE compliance or the Waste Electrical and Electronic Equipment directive which is responsible for the proper disposal of much the same equipment that RoHS regulates.

Like it or not, there are still electronics making their way to landfills even with available recycling facilities. As PCB designers, you can play your part to minimize the impact of electronics waste on the environment.

Biodegradable PCB

At the moment of writing, biodegradable PCB is yet to be a reality, but researchers have made headways into it. A group of researchers have managed to substitute conventional metal conductor in PCB to with transient metal paste made of Zinc and Tungsten.

These transient metals will gradually dissolve after being submerged in water. While more studies need to be done, the demonstration of a water-soluble PCB is promising progress when electronics waste is an increasingly serious threat to the environment.

Design For Serviceability

It will be foolish to assume every single PCB that is deployed will last for a decade or so. There are bound to be defects, damage due to wear and tear or electrical transient. In such situations, a PCB that is designed for serviceability increases the possibility of a repair being carried out instead of ending in the landfill.

Designing for serviceability involves various considerations. For instance, you’ll want to ensure components are properly labeled, so technical personnel is able to locate and rectify the faults with ease. It also means allocating surge suppressing components if the PCB is being used in an outdoor setting.

Modular Design

It’s understandable that consumer products are pushing for smaller sizes. However, when you’re involved in commercial or industrial applications where size isn’t a critical factor, consider taking a modular approach in your PCB design.

Instead of a single PCB, it makes sense to split the design into a couple or more parts. For instance, the microcontroller and other SMD ICs are placed on one PCB, and wire-to-board connectors are on another PCB.

With this approach, an upgrade on the MCU or SMD ICs will only result in replacing half of the total size of PCB. PCB modular design involves precise dimension to ensure the multiple PCBs are accurately connected particularly when built in a stackable manner.