Fatin Battal
Fatin Battal

Why is it so difficult to recycle electronic devices?

Electronic products are often treated as disposable items. Broken screen? Throw it away. Computer too slow? Off to the recycling centre. As a result, electronic waste—alongside plastics—is the fastest-growing waste stream in the world. This needs to become much more circular. And that is precisely what John Schermer and Fatin Battal from Radboud University are working on within the Circular Circuits project.

E-waste

A major problem with electronics is that they require many materials. Since the 1970s, the amount of materials we extract from the earth for our electronics has tripled to 90 billion tonnes. And it is expected that by 2050, this will have increased another two to three times. This means that we need more and more raw materials, while supplies are dwindling. The EU classifies 34 raw materials as 'critical': economically crucial and at high risk of supply issues (source). Most of these critical raw materials, such semiconductors and metals, are used in our electronics. And this leads to several problems, explains John Schermer, Associate Professor of Applied Materials Science: 

‘The raw materials are scarce, and we use them inefficiently. We need more and more of them. However, mining these materials is often dangerous and leads to negative environmental effects, such as climate change and biodiversity loss. Secondly, we use our electronics for a relatively short time, causing the materials they contain to quickly be classified as waste. These materials are rarely recovered, making us increasingly dependent on a limited number of suppliers. Recycling materials is difficult, and poorly processed e-waste also leads to pollution and health risks.’ 

Circular Circuits 

In the Circular Circuits project, researchers from seven Dutch universities are working with companies linked to the semiconductor industry on a new generation of circular electronics. They aim to eliminate the concept of e-waste, extend the lifespan of products, and work towards a fully closed circular electronics economy. Additionally, they want to find solutions for using raw materials more efficiently, so that we need less of them. Battal (PhD candidate at Applied Material Science) and Schermer focus within Circular Circuits on 'lifetime extending technology (manufacturing)'. 

To work towards an industry-wide solution for extending the lifespan of electronics, a detailed approach is required. ‘We focus on the reliability of semiconductor components. These are very small parts of a device, but you can consider them the heart of our electronics. For example, think of a laptop: it contains a motherboard with various microelectronic components - better known as chips. All those chips have their own function. Currently, it is almost impossible to replace individual chips. So, if one chip on your motherboard breaks, you can throw away the laptop. The Circular Circuits program aims to modify electronic components so that they become more durable and also can be replaced and recycled,’ explains Battal. 

Power Electronics 

Battal and Schermer are researching chips that are used as power electronics. These are found in critical applications such as cars and airplanes where they endure harsh conditions. For instance, the chip can reach internal temperatures of up to 175 degrees, which means it must withstand heat well. This also applies to the connection of the semiconductor part of the chip to its lead-frame (the thin metal structure that connects the chip to the outside world). Heat induced stresses cause the interconnection between the chip and this frame to fail after a certain period of time.   

Battal: “We are focusing on finding new structured materials to connect semiconductors to the metal lead-frame that can withstand harsh conditions and thus last longer.” 

Fatin Battal in het lab

From Lead to Copper 

Traditionally semiconductor chips are integrated to their metal carrier frame using a lead-based solder connection. These connections are very reliable and durable, but under new European regulations, this can no longer be used as lead is a toxic substance. Schermer: ‘ However, for critical applications the EU still grants waivers to use lead-based solders as lead-free alternatives are way less reliable and durable. Research showed that it is impossible to obtain the same superior interconnect properties by replace lead with an alternative drop-in element. Some gold-based solders come close but have the additional problem to be very expensive. That is why we are now investigating a fundamentally different approach to use nano-structured copper for the integration of the semiconductor chip with its metal carrier. 

Challenges 

Battal: ‘To create nano-structured interfaces, we need to make very small pores in the copper. This is quite a challenge because it has never been done in the way we envision. The aim is to tune the pore size and density in such a way that during the subsequent mounting cycle an interconnect is created that equals or even surpasses the quality of a lead-based soldering connection. Fortunately, we are not alone in the development of this approach. Within Circular Circuits we have a close cooperation with our colleagues at Delft University. But closer to home, we have support as well, such as from the NMR group in our own faculty. And we are, of course, fortunate that two of our industrial partners, Nexperia and NXP, are located nearby. We can easily coordinate and work out the different parts of our research together.’ 

Parallel to our research to extent the durability of power electronics the other project teams are looking at different parts of the puzzle: for example, how to extract and recycle the materials from broken electronic components. Ultimately, each project team contributes to the bigger picture. Battal: 'I hope that in 5 to 10 years, the solution we have devised will be implemented across the entire semiconductor industry. And possibly even beyond. In this way, our fundamental research contributes to making our electronics circular.' 

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Contact information

Contact
Dr J.J. Schermer (John) , F. Battal (Fatin)
About person
F. Battal (Fatin) , Dr J.J. Schermer (John)
Theme
Molecules and materials