Design for Electronics Recycling: Best Practices

November 22, 2019 Cadence PCB Solutions

Pile of unusable PCBs

Obsolete circuit boards

 

One of my favorite tag lines from a commercial is “What if…” that Hewlett Packard used over two decades ago. The point was that innovation always begins by asking the question what if we do something different from has already been done. This premise was true then and it remains so today. By acknowledging that the potential of this simple concept any problem, regardless of how insurmountable it may seem, can be solved. 

One problem that many people would rather sweep under the rug is the downside of some of the greatest technological advancements. Examples include: what do we do with the radioactive materials from nuclear power plants and the ever-increasing tonnage of plastics that can take up to 1000 years to decay. Another significant issue is what to do with damaged or obsolete circuit boards and electronics. 

All of these problems have required that we take a what if approach to waste disposal. The innovative result has been to recognize that mush of what we deem to be waste can actually be reused. In the case of PCBs and electronics, one promising solution is recycling. Let’s explore this waste reduction strategy targeted at circuit boards in more detail and see how we can employ design for electronics recycling to promote and facilitate its success.

What is Design for Electronics Recycling? 

Design for electronics recycling can be described as follows:

Design for electronic recycling is the application of steps and concepts during the design stage of electronic development such that some or all of the electronic device or product can be recycled for further use after the device or product has reached the end of Its operational life. 

 

The fact is that most electronic devices are discarded due to some malfunction that may be deemed to costly to fix or the end-user wants to upgrade to a product with more capability or greater functionality. It is also true that devices do at times become damaged. Nevertheless, in all but extreme situations, some of the materials and/or components of PCBs, which comprise virtually all electronic devices, are salvageable. 

To harvest these resources for usage on other boards or in other devices, the products need to be able to be disassembled such as illustrated in the figure below.

A mobile phone in disassembly

Disassembled electronics device

 

Above, a disassembled cellular phone is shown. Discarded cell phones are one of the greatest contributors to electronic-waste (e-waste) or discarded electronics devices. According to the Global E-Waste Monitor, e-waste generation reached 44.7 million metric tons in 2016 and is projected to continue to climb. Most troubling is that it is estimated that only 20% of this waste was disposed of properly. Obviously, this problem requires an innovative approach such as green PCB development.

Why Should I Create a Green PCB Development Process?

Before, answering why let’s first address what is a green PCB development process. Obviously, the use of the adjective “green” denotes environmental consideration. Specifically, what decisions or actions can be made or instituted during PCB development that will lessen any negative impacts on the environment or global eco-system associated with the manufacture, operation or disposal of electronic circuit boards. 

Clearly, e-waste is having a negative impact on the environment; therefore, there is a need for electronics recycling. Recycling PCBs is most effective when it is supported by the entire development process. Therefore, the best strategy for reducing e-waste requires that design for electronics recycling and manufacturing for electronics recycling be incorporated. The EU, on the other hand, has strict regulations concerning the use of chemicals classified as hazardous and e-waste that apply to devices manufactured locally and imported. 

Reasons to Adopt a Green PCB Development Process:

  1. Recoup precious metals

Circuit boards invariably contain gold, copper and other metals that are “precious” for words, the PCB development process should be green and there are several reasons why as listed below.

  1. Regulatory compliance

Over half the states in the US regulate electronics recycling, but no federal standard is in building PCBs and recovering these metals from obsolete boards can be quite substantial. For example, Apple reported recouping 2204 lbs of gold in 2015

  1. Lower manufacturing costs

By using recycled components and smaller board designs, the costs for manufacturing can be lessened and productivity increased.

  1. Reduce hazardous waste exposure

Another major reason that more green PCB development is needed is to minimize the exposure to hazardous wastes by workers in mostly third world countries. Most e-waste is exported to a few countries in Asia and Africa and stored in landfills. Prior to burning, local residents harvest parts and materials from the devices and in the process expose themselves to potentially harmful chemicals and materials.   

 

Executing an effective green PCB development process means that you must partner with a contract manufacturer (CM) that is committed to sustainable manufacturing to support and ensure the manufacturability of your design for electronics recycling strategy. 

How Do I Implement Design for Electronics Recycling?

Now, that we know what design for electronics recycling is and why we should adopt a green PCB development process that incorporates it we can address how to implement it. Generally, any design choice; including selected components and connectors, trace routing, board size, stackup and material options that make the device more reliable (likely to last longer than its operational lifetime), safer (less likely to suffer damage), smaller (miniaturization uses fewer materials and components) faster or easier to disassemble (without destruction) may contribute to a design for electronics recycling plan or strategy. Some best practices to follow are listed below.

 

Best Practices for Design for Electronics Recycling:

♻    Use smaller more compact board design

♻    Minimize the number of components

♻    Minimize the number of fasteners or connectors

♻    Minimize different types of plastics and metals

♻    Minimize use of plated or contaminated metals

♻    Do not use nuts and bolts

♻    Minimize adhesives for plastic parts

♻    Follow regulations and standards; such as RoHS. 

 

The list above is not exhaustive, but it does provide sound practices that will contribute to the success of your design for electronics recycling strategy. However, the best design strategy is devised when you have the most capability to explore “what if” options that can make your board easier or faster to disassemble.

 

Design that employs consistency of material and component selection

Use of similar materials and components

 

By using Cadence’s PCB Design and Analysis Software you have all the tools at your fingertips to explore and create the best design for electronics recycling. Explore What's New in Allegro PCB Design, and try to challenge your designs to go further than before. 

If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts

About the Author

Cadence PCB solutions is a complete front to back design tool to enable fast and efficient product creation. Cadence enables users accurately shorten design cycles to hand off to manufacturing through modern, IPC-2581 industry standard.

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