Infineon to offer recyclable circuit boards that dissolve in water

Infineon Technologies will using recyclable printed circuit boards (PCBs) based on a material developed by a UK startup in upcoming demo boards.

The technology is claimed to be more environmentally friendly and to reduce the carbon footprint of the electronics industry.

Germany's largest semiconductor maker said it is introducing products using Soluboard, a recyclable and biodegradable circuit board substrate material based on natural fibers, which are claimed to have a much lower carbon footprint than the glass-reinforced epoxy resin laminate which is typically used for PCBs.

Soluboard gets its name because the plant-based material it is composed of is enclosed in a non-toxic polymer that dissolves when immersed in hot water, leaving behind only compostable organic material. The electronic components soldered to the board can then be recovered and recycled, we're told.

Initially, Infineon will be using Soluboard for demo and evaluation circuit boards, but the company said it is considering using the technology in all products with a PCB in future.

“Infineon is using the biodegradable material to reduce the carbon footprint of demo and evaluation boards, but also exploring the possibility of using the material for all boards to make the electronics industry more sustainable,” the company’s Division President for Green Industrial Power Peter Wawer told us.

Small quantities of selected boards have already been shared with selected customers, Wawer said, and the products will be available via Infineon's established channels from Q4 of 2023.

Soluboard is produced by Jiva Materials, a UK startup based in Waterlooville, Hampshire. CEO and co-founder Dr Jonathan Swanston told The Register it was developed by Chief Product Officer Jack Herring while he was studying product design at the RCA in London. The pair raised seed funding of £850k (about $1 million) in 2019/2020 to start the company.

Electronics waste is the fastest growing waste stream in the world and electronics often use critical minerals and expensive components that have lifetimes longer than the life of the circuit boards, Swanston said.

“Currently the way that electronic waste is treated is by shredding, followed by either burning or landfill, which leads to pollution,” he told us. “The idea was to re-engineer the traditional laminate to allow for easier recycling.”

In Soluboard, the glass fiber and epoxy resin of traditional PCBs are replaced with a natural fiber and a polymer that dissolves in hot water.

The latter may sound like a liability if any liquid should get spilled onto an electronic device somehow, but it seems that it requires a fair amount of water and a continuous high temperature to degrade Soluboard.

“Soluboard printed circuit boards need to be immersed in 90°C water (close to boiling point) for 30 minutes for the product to delaminate,” Swanston told us.

There are then three streams to recycle – the metals and components, the natural fibres and the polymer solution.

“The polymer solution can be disposed of through domestic waste water treatment and the fibres composted or re-used and the metals and components can be recycled or reused,” Swanston said.

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Infineon is actively researching the reusability of its discrete power devices, because they weren't designed with this method of recycling in mind.

“Our products are designed and qualified to survive in harsh environments and use cases, but literally putting the devices into cooking water for quite some time is not currently part of these use cases,” Wawer told The Reg.

Soluboard manufacturing also results in 60 percent less carbon dioxide emissions than the process to produce traditional circuit board substrates, Jiva claims.

However, one potential limitation is that Soluboard can currently only be used to make printed circuit boards that have a single layer of tracks on one or both sides, whereas complex products may have multiple layers of tracks with insulating layers in between them.

“Soluboard is currently only suitable for single and double sided printed circuit boards, but this is a significant market,” Swanston said, adding that Jiva has a technology road map to make a laminate suitable for multi-layer boards and expects to be able to supply this market in the next few years.

Keep an eye on collection and recovery process

Soluboard is also likely to be more costly, at least to start with, and will have a premium of 50 to 75 percent over the cost of current substrates.

“Traditional PCB materials are made at a very significant scale; there is more than 250 million square meters made every year. If Soluboard was made at that scale its price would be equivalent,” Swanston claimed.

IDC Senior Research Director for Europe Andrew Buss said any technology development which makes it easier to recycle or use recycled materials is welcome, but the inability to support multiple layers may limit its appeal for now.

“For most PC or server systems, the boards are heavily multi-layered these days so this would not be suitable for those products at this time, and the market may be centered around more basic PCB requirements in areas such as consumer electronics,” he said.

"The key will be how many layers can this scale to and how dense," he added.

But Omdia Principal Analyst Manoj Sukumaran was more dismissive, and said he didn’t believe technology such as this would have any significant impact on the industry at any time soon.

“Other important PCB characteristics include the ability to dissipate heat, fire resistance and mechanical stability (it should not break easily). To what extent a water soluble material can offer these features is questionable,” he said.

Sukumaran also told us he was skeptical that any significant value would come of recycling components from such circuits. “The collection and recovery process cost itself could be multiple times the component costs,” he said.

Swanston, however, said he believed that Soluboard might be used in the majority of circuit board designs in future.

“It can be used for the majority of rigid PCBs currently in single and double-sided commodity boards and in the future in multi-layer PCBs. It won’t be suitable for flexible circuit boards,” he said. ®