Room Temperature Soldering Possibly with Liquid Metal "Balloons"

[Godlygamer23]

Soldering is a technique of taking molten metal alloys and putting them on two pieces of metal to join them together in an electrical connection - normally, solder has to be heated to a very high temperature in order to become molten. However, with this new technique, we might be able to throw that away. The main issue with current soldering is that you have the potential of burning components on the board, and even yourself with the temperature that soldering irons run at. Martin Thuo at the Iowa State University has developed a new way of soldering through an alloy that consists of bismuth, indium, and tin which is called "Field's Metal." This alloy melts at 62C - however, if the tiny droplets of this material(while molten) are placed inside protective shells, the material remains in a liquid form when the shell cools and solidifies.

 

The effect - which is known as undercooling or supercooling - occurs because the liquid metal is prevented from coming into contact with something that triggers any kind of solidification. While it was studied extensively, we couldn't make a stable undercooled metal material that was readily usable. When you crush the particles, liquid metal is released onto the surface, when then becomes a solid, conductive solder joint.

 

Thuo's team was able to put the special particles onto a thin film of gold, and then placed a gold wire on top. They put a glass rod onto it to squish the particles, and within seconds, the wire was firmly stuck to the film. Additionally, the particles could also repair a hole in a thin film of silver, and stick foils of gold and aluminum together. If precision is required while soldering, a scanning electron microscope can also be used to puncture the particles.

 

The team made these particles by taking some Field's Metal to some acetic acid using a solvent known as diethylene glycol, and then spinning it at 17,000 RPMs.

Quote taken directly from the source:

Quote

 

Thuo’s team made the particles by adding molten Field’s metal to a solution of acetic acid in a common solvent called diethylene glycol, and whizzing it up with a power tool running at 17,000 r.p.m. to break the metal into tiny droplets. (“A heated soup maker also gives really good particles,” notes Thuo.)

The droplets first react with air to form a thin oxide shell that is less than a nanometre thick, and then further react with acetic acid to form a second nanolayer. This adds flexibility so that the shell doesn’t crumble once it cools. Changing the details of the recipe, such as the viscosity of the liquid or the blending speed, can produce particles ranging in size from 4 nanometres to 5 micrometres in diameter. Once the particles have been filtered from solution, they can be stored for months without breaking down. Thuo has recently set up a company called Safi-Tech to commercialize the technology, and hopes to sell the particles to the microelectronics industry.

In accordance with Liu, he says that he thinks the manufacturing looks scalable. However, he also realizes the industry would like to know if the method can even be trusted in the first place as a replacement for our current technique. Thuo's team is currently testing other alloys which melt at a higher temperature than Field's Metal, and they've been successful. They've found that bismuth and tin mixed together can also be encapsulated inside the protective shell while remaining in a liquid form, bearing in mind that the melting temperature of this mixture is normally 139C.

 

Source: http://www.nature.com/news/liquid-metal-balloons-offer-room-temperature-soldering-1.19495

Edited March 7, 2016 by Godlygamer23
Slight edit to formatting and typo fixes.

[Orangeator]

Thanks for the share, this is super interesting. I wonder if they will ever sell "kits" of this?

[Enderman]

SO what happens if you get one of these balloons in your eye and it pops? Do you get a core eye-7?

[ivan134]

1 minute ago, Enderman said:

SO what happens if you get one of these balloons in your eye and it pops? Do you get a core eye-7?

[2FA]

If this technique is practible on large scale manufacturing, it could have a huge impact on the electronics/computer industry.

[AlwaysFSX]

Is the solidification a permanent thing or not? Do the the films over the metals that prevent them from turning back in to a liquid/pressure changes the structures making them solid at those temperatures?

[Godlygamer23]

Just now, AlwaysFSX said:

Is the solidification a permanent thing or not?

I imagine de-soldering would still be a thing. If not, I cannot see this technique taking wide acceptance.

[AlwaysFSX]

Just now, Godlygamer23 said:

I imagine de-soldering would still be a thing. If not, I cannot see this technique taking wide acceptance.

I just don't see how they can go from a liquid to a solid at the same temperature without changing either the metal structures or preventing the metals from reacting with something in the atmosphere (which would be fun to scratch the fancy solder and everything melts apart) because computer components can hit 63C quite easily on the solder points. It just seems like it could fall apart.

[Godlygamer23]

24 minutes ago, AlwaysFSX said:

I just don't see how they can go from a liquid to a solid at the same temperature without changing either the metal structures or preventing the metals from reacting with something in the atmosphere (which would be fun to scratch the fancy solder and everything melts apart) because computer components can hit 63C quite easily on the solder points. It just seems like it could fall apart.

Apparently, they're developing it further to have a melting temperature of 139C with the new mixture at the bottom.

[Beskamir]

1 hour ago, Enderman said:

SO what happens if you get one of these balloons in your eye and it pops? Do you get a core eye-7?

rip

[SpaceNugget]

2 hours ago, DeadEyePsycho said:

If this technique is practible on large scale manufacturing, it could have a huge impact on the electronics/computer industry.

I don't really see how. They dont solder many things by hand in the first place, most modern electronics manufactured at scale are wave soldered anyway.

[Stefan1024]

The metal they use looks super expensive. Also most electronic parts have no problem to be heated up to 350C as long as the slope is controlled. considering the electronic market is extremly cost sensitive I can't see this happen on a large scale. And for labor use there is already solder with a melting point aroung 150C. But if you are a bit experienced with sonldering you hardly ever kill a component with heat despite using normal solder. 

[Daegun]

2 hours ago, AlwaysFSX said:

I just don't see how they can go from a liquid to a solid at the same temperature without changing either the metal structures or preventing the metals from reacting with something in the atmosphere (which would be fun to scratch the fancy solder and everything melts apart) because computer components can hit 63C quite easily on the solder points. It just seems like it could fall apart.

If I'm understanding it right, it should work just like this does. 

Beyond needing to react with air, it needs a point, an imperfection in a surface, to harden around or some kind of disturbance.

[Dabombinable]

So soldering IHS to 22nm and smaller CPU die is possible? Because I can say right now-my i7 4790K gets hotter at stock than my Xeon X5450 at 3.6GHz, with the Xeon consuming a lot more power (well over 120W) and using the same cooler+thermal paste.

[Lazmarr]

6 hours ago, Godlygamer23 said:

-snip-

But it would require a soldering iron to remove the solder off of the soldered joints. It's ok if you're making a one time thing with no corrections but if you make a mistake or want to change something you will still need to desolder it with a soldering iron.

[Prysin]

6 hours ago, Enderman said:

SO what happens if you get one of these balloons in your eye and it pops? Do you get a core eye-7?

nah, eye-5

Hyperthreading wont be enabled just like that you know....

[Doobeedoo]

I wanna try this.