News Water-Soluble PCBs Are Major Step Towards Recyclable Electronics

Eximo

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I prefer IBMs water powered concept. Why use power traces when you can use conductive coolant lines?

Still, first thing I thought of was, how hot this water has to be. Because a 95C CPU is really close to boiling...
 
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LabRat 891

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This is dumber than PCW Cardboard Chassis/enclosures/cases.

Honestly, I see more applications for this technology in espionage than consumer products. -'bout the only field 'self-destructing' devices are actually warranted.
 

InvalidError

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Making PCBs out of something that reacts with water sounds problematic when ultrasound washing is usually part of the manufacturing process to remove flux and other residue along the way.

It would make more sense to search for polymers that are soluble in things that don't occur under normal operating and manufacturing conditions such as supercritical CO2.
 

InvalidError

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This might be OK for stuff that people never open. Like a ROKU or the motherboard for TVs.
You'd have to remove water from cleanup steps during manufacturing and make sure anyone who might open the things to repair know they cannot use water for cleaning either. Alcohol is hygroscopic, so you'd have to avoid using alcohol-based solvents, cleaners and fluxes from anything other than a freshly unsealed bottle on those PCBs too. There is also the risk of the boards turning to mush from high-moisture environments. How many foggy days would such boards survive?
 

GenericUser

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I think the main issue with allowing something other than water to dissolve the PCB is that it still requires an active step to initiate the process. Most people are just going to throw whatever the device is into the trash without doing anything else when they're done with it, which in that case is functionally equivalent to not having it be biodegradable in the first place.

Having it dissolved by water at least makes it so that anyone can toss it with there still being some reasonable confidence that it will have a chance to properly biodegrade, but obviously the shortcomings everyone has already pointed out with that make it not really a good idea, so back to square one.

Having a biodegradation process initiated with a different solvent I think could still be useful to augment dedicated disposal/recycling processes, but again, I think most people are just throwing their electronics in the trash, so the majority of e-waste wouldn't benefit from it since those products won't reach the channels for proper disposal anyway.
 

InvalidError

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I think most people are just throwing their electronics in the trash, so the majority of e-waste wouldn't benefit from it since those products won't reach the channels for proper disposal anyway.
The e-waste problem may solve itself as pressure increases to preserve supplies of some rare elements like how the DoD is now investing money in recovering gallium from electronics to secure supply it can no longer obtain directly from China. The prices of most metals have gone up considerably too, which increases the incentives to revisit "mining" landfills.

Someday, we'll probably reach the point where scrappers will be buying e-waste for recoverable rare elements value and devices have a deposit on them to encourage returning them at the end of their useful life.
 

Matt_ogu812

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Water-Soluble PCBs Are Major Step Towards Recyclable Electronics​

The gateway to a biological computer like our brain?
Brain Banks are always looking for donators.
 
I think the main issue with allowing something other than water to dissolve the PCB is that it still requires an active step to initiate the process. Most people are just going to throw whatever the device is into the trash without doing anything else when they're done with it, which in that case is functionally equivalent to not having it be biodegradable in the first place.

Having it dissolved by water at least makes it so that anyone can toss it with there still being some reasonable confidence that it will have a chance to properly biodegrade, but obviously the shortcomings everyone has already pointed out with that make it not really a good idea, so back to square one.

Having a biodegradation process initiated with a different solvent I think could still be useful to augment dedicated disposal/recycling processes, but again, I think most people are just throwing their electronics in the trash, so the majority of e-waste wouldn't benefit from it since those products won't reach the channels for proper disposal anyway.
But if people just toss out a device, how much does it really matter whether the circuit board is water-soluble when it's only a small part of the device as a whole, and will likely be housed in a thick plastic case that is unlikely to easily break down. And on the topic of the possibility of mining landfills, having a circuit board decompose might make it more difficult to recover precious metals from it in the future. Ideally you would want incentives to discourage people from tossing newer electronics in the trash in the first place though. A deposit might work, though if it's too much, that might also make people more prone to get rid of perfectly functional older hardware just to get their deposit back.

Making circuit boards that can break down could be good, but they would still need to be very robust, and require long-term exposure to environmental moisture for that to happen. Like a material that might still take hundreds of years before it starts to break down in a natural environment. And maybe that's what they are doing here with the coating that dissolves in hot water. As for hot components warming the board, they could likely just use an additional, non-water-soluble coating to keep moisture away from the parts of the board that are subjected to high temperatures under normal use.
 

InvalidError

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As for hot components warming the board, they could likely just use an additional, non-water-soluble coating to keep moisture away from the parts of the board that are subjected to high temperatures under normal use.
It may sound nice in theory but in practice, even thick plastics are permeable to moisture with long-term exposure. In the consumer space, you can witness this with 3D-printer where leaving filament in open air for a few days can be enough to start having issues with stringing and bubbles from filament moisture boiling inside the hot-end.

Moisture gets everywhere, you cannot depend on sealants alone to keep stuff dry. Even if a sealant coating could do the job, it would only be one scratch away from letting moisture through and PCBs tend to get scratched around mechanical features like holes, tabs, card edge connectors, etc. For a sealant coating to be effective, coverage would also need to encroach onto solder pads to leave no substrate exposed.
 

USAFRet

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In the consumer space, you can witness this with 3D-printer where leaving filament in open air for a few days can be enough to start having issues with stringing and bubbles from filament moisture boiling inside the hot-end.
Lest anyone pooh pooh this because "plastic can't absorb moisture"...it is absolutely a thing.
To the point that I bought a dehydrator for this exact purpose. And it absolutely makes a difference.