Unzipping the Future of Sustainable Electronics
In2Tec brings an innovative closed-loop solution to the global e-waste problem.
Electronic-systems designers are facing a serious reckoning: How to significantly reduce the environmental impact of more and more electronic content in new vehicles?
E-waste—the mountains of discarded electronic refuse piling up all over the planet—are a global problem that is getting worse each year (see sidebar). And while consumer electronics are the primary constituent in e-waste, the auto industry is steadily exacerbating the mess. With the addition of on-board processors for every new function, and a sensor deluge with no end in sight, a typical passenger vehicle can contain up to 200 electronic control units. Each ECU has a printed circuit board assembly (PCBA) that are difficult and costly to disassemble and reclaim. While the scrapped boards have component and material salvage value, most go to landfill, according to the U.S. EPA.
Discrete solutions for recycling PCBAs and curbing the downstream nightmare have been proposed by industry suppliers. One company, In2Tec Ltd., an electronics designer and manufacturer, is taking a broader view. Its leaders believe true sustainability in electronics requires a circular-economy approach. Their solution combines product innovation with closed-loop, low-impact PCBA manufacturing and reprocessing that company engineers aim to demonstrate in a pilot facility now under development.
“E-waste is becoming like the plastic-bag issue, driven by consumers and government,” Neil Armstrong, In2Tec’s group managing director, said in an interview with SAE Media. To mitigate the waste stream at its source, the auto industry needs to be proactive, he asserted, rather than “being dragged kicking and screaming into confronting it.”
In2Tec’s goal, he asserted, is to use its technology to deliver PCBAs that have “the highest recyclability in the industry.” To do so, the Kettering, U.K.-based company has focused on flexible-substrate technologies and sustainable electronic solutions since its founding over 25 years ago, Armstrong stated. It serves an array of industrial sectors including medical and aerospace, and counts Porsche, Aston Martin, Konigsegg, and various Formula 1 and World Rally teams as customers for its package-efficient HMI solutions.
In2Tec has manufacturing plants in the U.K. and China. But with one-third of its resources devoted to R&D, the company has long recognized an opportunity to shift the paradigm in PCBA manufacturing and reclamation toward a sustainable model.
The new process has been in the works for 10 years. With funding from Britain’s Technology Strategy Board (an innovation incubator) and in collaboration with the National Physical Laboratory and Gwent Electronic Materials, In2Tec has developed ReUSE, described by the company as a trademarked “cradle-to-grave technology that delivers re-usable and undamaged materials ready to provide secondary use.”
PCBAs made to the ReUSE spec are “unzippable—meaning we utilize hot water [90-deg. C/194-deg. F], applied within a three-to-six-minute cycle, to remove the components from the flexible substrate,” CTO Mark Hudman said. The overall process, most of which is patent pending, consumes minimal energy. It also results in a clean board surface, and “provides opportunity to reuse about 90 percent of the original substrate and nearly all of the components on that printed circuit board, at some level.”
By comparison, currently there are at least a dozen companies including majors Boliden Group and Umicore N.V. that dismantle PCBAs. The energy and effort required in their efforts is significant. A widely used and rather primitive method is mechanical recycling; it selectively dismantles and crushes the board, then uses magnetic or electrostatic tools to harvest various metal particles. Among chemical and thermal processes are salt and acid baths. One uses methylphenyl silicone oil as a medium to transmit heat ultrasonically to the PCBA.
Today’s most common board material FR4 (a rigid glass-fiber epoxy laminate) with soldered component connections offers 5% recyclability, at best, he said. The process is amenable to both flexible and rigid printed circuits. In2Tec offer various substrate materials depending on the requirement of the end application and the program’s focus on recyclability, Hudman said. “We have PET [polyethylene terephthalate] and a variety of plastics including nanocellulose structures — essentially biodegradables.”
A key enabler of the In2Tec process are the substrate materials and conductive adhesives jointly developed with partner, Sun Chemical, a New Jersey-based provider of technologies for printed circuits. Hudman said compared with traditional solder and other adhesives, the Sun Chemical-developed adhesives are formulated to break down via high-temperature water, and thus loosen the PCBA components quickly. “This is sustained exposure to hot water for the 3-to-6-minute cycle to reduce the substrate-to-component bond by up to 90 percent,” he said. “Neither humidity by itself, nor dry heat, don’t affect it.” The process requires certain conditions, in sequence, to produce “a really robust solution,” Hudman explained.
For perspective, conductive adhesives used in PCBAs are much more flexible than solder and are therefore more vibration-resistant, according to experts. They can also be jet-printed or plotted. MasterBond, an electronics-adhesive supplier, cites adhesive curing temperatures that are significantly lower than the 450-deg. F (232-deg. C) minimum temperature required for lead-free solder processing. Typical temperatures for rapid cure adhesives are between 250-deg.F and 350-deg.F (121 to 177-deg. C).
“We realize that we won’t always be able to reuse the components in the applications they’ve come out of, say, an ECU or mobile phone PC board,” Armstrong noted. “But the reuse opportunities in less complex electronics is mind boggling. And the moment you start reusing electronic components, you have a significant energy and greenhouse-gas reduction on the manufacturing side when you use a component even one, two or three more times. Never mind the saving on Earth’s precious rare materials that are being consumed at a speed that scientists are now saying is un-recoverable.”
Unzipping the future
Development of more advanced flexible electronics for use across the vehicle is integral to further advancements in the ReUSE technology. “Flexible electronics breaks down design barriers in systems architectures,” Armstrong said. “We’ve developed solutions for printed and conformable antennas that can be fixed at any point in the vehicle. We’ve looked at transparent antennas for applications in light lenses. We’ve patented flat, twisted serial pairs for data communications, which are essentially printed CAN bus architectures.”
Integrating the electrical harness and PCBA could potentially eliminate connectors, which engineers say are responsible for more than 70% of the failure rate of vehicle electrical architectures. Flexible hybrid electronics (FHE), conductive ink printed on rolls of film-like substrate, was used by Ford on a limited trial bases in the overhead console of the 2013 Fusion and is being investigated by white-goods makers and the U.S. military (see February 2017: Print Your Next Wiring Harness). The concept can unlock further sustainable electronics innovation from In2Tec, Hudman and Armstrong said.
Automotive OEMs are traditionally reticent when step-change technologies emerge. But Armstrong senses their conservatism has moderated in the past year. “We’re engaged with companies that see ‘sustainable’ in their USP [unique selling proposition], who are now willing to deliver on real sustainability, to reduce CO2e,” he observed.
The industry has been without a robust and cost-effective recycling process for electronics. In2Tec will soon be demonstrating its patented approach. Armstrong promises “a very, very low barrier of entry” in delivering its closed loop solution. Unzipping microelectronic circuits has only just begun.
Buried in e-waste
The United Nations estimates that in 2021, each person on the planet produced on average 7.6 kg (16.7 lb.) of e-waste, contributing to a total of 57.4 million tons generated worldwide and growing annually. Only 17.4% of this electronic waste, itself a physical cocktail of toxic substances and valuable materials, will be properly collected, treated and recycled, the U.N. noted. China, the U.S., and India collectively account for 38% of global e-waste, according to the U.N.’s Global E-waste Monitor. In the EU, which leads the world in e-waste recycling, just 35% of e-waste was officially reported as properly collected and recycled. Globally, the average is 20%; the remaining 80% is undocumented. None is biodegradeable; much of it ends up buried under the ground for centuries as landfill.
Future prospects are not bright: the U.N. predicts global e-waste will reach 74 Mt by 2030. This nearly doubles the total of 2014, due to higher consumption rates of electric and electronic equipment designed for short life cycles and few options for repair.