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New Heat-Reduced Magnetic Solder Could Revolutionize Chip Design

ScuttleMonkey posted more than 4 years ago | from the vaporware-until-i-see-chips dept.

Hardware 103

A new heat-reduced soldering technique using magnets may lead to some revolutionary changes in the way chips are manufactured. Details are scant since the inventor seems to be playing it close to the vest for now in hopes of attracting chipmaker interest. "The result is a tin-silver alloy that contains a dispersion of iron particles tens of micrometers in diameter. When a magnetic field is applied to the solders, two things happen. First, the iron particles heat up, locally melting the solder. This localized heating, which works on the same principle as inductive stoves, remains completely contained, keeping the surrounding area cool. And second, the iron particles line up with the direction of the magnetic field, squeezing and pushing the liquid in that direction. This alignment is retained when the solder solidifies, and the well-ordered particles provide mechanical reinforcement that's greater than that afforded by a regular dispersion of particles."

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103 comments

Is methane involved? (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#31375096)

I gotz to know !

Wait.... (1, Insightful)

Moheeheeko (1682914) | more than 4 years ago | (#31375130)

...Using magnets to solder magnetic sensetive components? Ive got this great idea for a better wood glue! just expose it to fire and it holds 10x stronger and faster!

Re:Wait.... (0)

Anonymous Coward | more than 4 years ago | (#31375194)

Without a circuit there can be no magnetically induced current. This would work great for individual components, and you could leave final assembly in the realm of other soldering techniques.

physics: 1
your funny: 0

Re:Wait.... (2, Informative)

metamechanical (545566) | more than 4 years ago | (#31375344)

This would work great for individual components, and you could leave final assembly in the realm of other soldering techniques.

The only problem with that is that when you want to use two separate bonding techniques on a board, the cost and complexity skyrockets. This is why (or at least, one reason) this is traditionally avoided (the exception for that is reflow and wave soldering, which touch different component types... DIP vs. surface mount... even then though, the chemistries involved are frequently similar).

Even if you could manufacture that on the cheap, how are you going to support it? Throw away whole boards instead of rework/repair them? Some boards might be cheap enough to just throw away... but if they're that cheap, you're probably not using a fancy pants soldering technique anyhow.

Re:Wait.... (-1, Troll)

Anonymous Coward | more than 4 years ago | (#31375518)

Wave-soldering is a very tamper-tolerant technique.

We have a bunch of crazy Asian immigrants who used to stand and squat on the toilet seats when they took shits. After the toilets started breaking, we made them squat on top of the wave solder machine and shit into the molten solder pool. It reeks like a motherfucker, but the customer gets what they deserve when they use immigrant labor. Once in awhile, an Asian falls into the pool and we have to ladle his bones out at the end of the shift.

Are you man enough to stick your dick into a running pick-n-place?

Re:Wait.... (0, Offtopic)

fridaynightsmoke (1589903) | more than 4 years ago | (#31375574)

A racist with a working knowledge of electronic manufacturing?

Dave, is that you??

Re:Wait.... (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#31375818)

Dave's not here man.

Re:Wait.... (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#31376074)

No, I'M Dave, man!

Re:Wait.... (1, Interesting)

Anonymous Coward | more than 4 years ago | (#31375938)

Without a circuit there can be no magnetically induced current.

Wrong. You forget about capacitance. A small amount of current can be induced in any conductive material merely by moving the magnetic field around it. This current will be absorbed by capacitance (only to be re-emitted shortly thereafter). When you have bottlenecks in the material, like are found in any IC, the current may be enough to cause damage.

Re:Wait.... (1)

ircmaxell (1117387) | more than 4 years ago | (#31375242)

FTFS:

In contrast, the magnetic solder can be pulled up through silicon by using a relatively weak magnet

So it depends on their definition of relatively... Is that a household kitchen magnet (which would do little damage to most magnetic sensitive components once removed from the chip)? Or is it a 0.5T magnet (that's relatively weak compared to most MRI magnets and would likely saturate most magnetic sensitive components to the point of failure)?

Re:Wait.... (2, Insightful)

Carnildo (712617) | more than 4 years ago | (#31375396)

So it depends on their definition of relatively... Is that a household kitchen magnet (which would do little damage to most magnetic sensitive components once removed from the chip)? Or is it a 0.5T magnet (that's relatively weak compared to most MRI magnets and would likely saturate most magnetic sensitive components to the point of failure)?

Once the solder melts, it should be possible to shape it using a refrigerator magnet -- molten solder simply doesn't have much viscosity or structural strength. You don't need to worry, though: melting it is done by inductive heating, which requires a strong time-varying magnetic field.

No useful details in the article. (3, Informative)

Futurepower(R) (558542) | more than 4 years ago | (#31375706)

"When a magnetic field is applied to the solders, two things happen. First, the iron particles heat up, locally melting the solder. This localized heating, which works on the same principle as inductive stoves, remains completely contained, keeping the surrounding area cool."

Quote from ScuttleMonkey, the Slashdot editor: "Details are scant..."

Neither the Slashdot editor or the writer of the linked article understand the physics. Magnetic fields cause something to heat only if the field is rapidly changing. Then the magnetic field causes everything conductive to heat, including iron particles.

Re:No useful details in the article. (0)

Anonymous Coward | more than 4 years ago | (#31375866)

Might want to talk to the guys that play with induction heating... There are different heating mechanism than you pretend to know.

From http://4hv.org/e107_plugins/forum/forum_viewtopic.php?80493 [4hv.org]

>Copper requires much more workcoil current/reactive power because copper has no hysteresis losses while iron does have. So all we have here is eddy current losses to be play with.

I personally don't think placing such a magnetic field to the delicate circuit next to a chip is good.

Re:No useful details in the article. (1)

TheTurtlesMoves (1442727) | more than 4 years ago | (#31379898)

Inductive Aluminum smelting is pretty common. It has no hysteresis losses either. In fact in every commercial setting I have ever heard of the predominant heading method is current induction, not hysteresis heating. Hence the term induction heating.....

Re:Wait.... (1)

Jeng (926980) | more than 4 years ago | (#31375294)

Sounds to me like the heat can be applied more precisely with this method than the current method.

Fairly sure there is wood glue that does hold much stronger if you heat it while it sets.

Re:Wait.... (0)

Anonymous Coward | more than 4 years ago | (#31375424)

Sounds to me like it might be a little too precisely. You're not going to get good wetting if you just heat the solder.

Re:Wait.... (1)

Jeng (926980) | more than 4 years ago | (#31375492)

Thinking about it further, why not just use a laser?

Wouldn't even need to contaminate the solder with iron.

Re:Wait.... (1)

zill (1690130) | more than 4 years ago | (#31377714)

The unemployment rate is already bad enough.

We don't need sharks to displace even more workers off the assembly line.

"Magnetic sensitive components"? (4, Informative)

DeadCatX2 (950953) | more than 4 years ago | (#31375978)

When you bring a magnet near a PC, the damage is done to magnetic recording media, not the chips. Silicon is not generally sensitive to magnetic fields. This guy [magconcept.com] has managed to put a video game controllers, keyboards, and mice inside an MRI bore. If those integrated circuits can work in a 3T magnetic field, I'm pretty sure it can survive this new magnetic assembly technique.

Re:"Magnetic sensitive components"? (1)

Demonantis (1340557) | more than 4 years ago | (#31376178)

Magnetic sensitive components are now usually shielded. Floppies and other magnetic media were the most susceptible so most people don't have to worry about it much now a days. Plus most shielding is just a faraday cage or iron like the outside of the computer case. HDD have the same issue and have a metal case. As well there are magnets anyways in the hard drives to move the IO head. This technology is actually exciting if you can get a consistent solder. It might even do away with microscopes for some soldering jobs.

Re:"Magnetic sensitive components"? (2, Insightful)

DeadCatX2 (950953) | more than 4 years ago | (#31376398)

You're tellin' me! Two of the PCBs I designed use FPGAs, one of them a BGA package. It's quite the trade-off when choosing an oven profile that gets hot enough for long enough to melt the solder but not destroy the FPGA (stupid lead-free solder!). Lower temperatures would make our life a lot easier...

You're thinking in one area of geekiness. (1)

Khyber (864651) | more than 4 years ago | (#31378194)

This could be absolutely awesome for surface-mounted diodes, which are quite sensitive to heat, requiring reflux soldering techniques for now.

What about the RF characteristics? (3, Insightful)

jcr (53032) | more than 4 years ago | (#31375144)

How much iron are we talking about? Is this tantamount to having ferrite beads on all connections now?

-jcr

Re:What about the RF characteristics? (2, Funny)

Anonymous Coward | more than 4 years ago | (#31375300)

How much iron are we talking about? Is this tantalum to having ferrite beads on all connections now?

-jcr

re-engineered that for you.

Re:What about the RF characteristics? (1)

macraig (621737) | more than 4 years ago | (#31375400)

Maybe about the same amount found in JB Weld, only much much finer particles.

Re:What about the RF characteristics? (1)

toastar (573882) | more than 4 years ago | (#31376016)

sorry for the diversion, But JB Weld is awesome!

Re:What about the RF characteristics? (2, Funny)

macraig (621737) | more than 4 years ago | (#31376344)

That's not a diversion, you're cementing the point and expressing solidarity.

Re:What about the RF characteristics? (1)

geminidomino (614729) | more than 4 years ago | (#31377144)

That's not a diversion, you're cementing the point and expressing solidarity.

Go sit in the corner.

Re:What about the RF characteristics? (1)

rts008 (812749) | more than 4 years ago | (#31376772)

I heartily second that!

I figure with a tube of JB Weld, a roll of Duct/Duck tape, and some baling wire, the possibilities are limitless.
You might even be able to take over the Universe!

Why, if MacGyver had JB Weld we would not be stuck with re-runs...the plot possibilities just don't stop with JB Weld!

Okay, I'm starting to sound like a shill(just a happy customer), so I'll quit now. :-)

Re:What about the RF characteristics? (2, Informative)

drerwk (695572) | more than 4 years ago | (#31375406)

No. First, iron and ferrite are not always the same thing, so it might just be iron in the solder. Second, the geometry matters, and the spheres are not beads.

Re:What about the RF characteristics? (1)

Dishevel (1105119) | more than 4 years ago | (#31375524)

Would not all spheres exist within the set of beads. Although not all beads exist within the sphere set.

Re:What about the RF characteristics? (1)

drerwk (695572) | more than 4 years ago | (#31375980)

A bead is a doughnut. A sphere is not. On this point the sets are disjoint.

Re:What about the RF characteristics? (1, Funny)

Anonymous Coward | more than 4 years ago | (#31377892)

Care to try that in haiku?

Re:What about the RF characteristics? (1)

biryokumaru (822262) | more than 4 years ago | (#31378440)

Beads are all doughnuts.
Spheres do not have holes in them.
The sets are disjoint.

Re:What about the RF characteristics? (2, Interesting)

Sponge Bath (413667) | more than 4 years ago | (#31375546)

I don't think the particles are spheres. The article says tens of microns in diameter, but also says the particles align to the magnetic field and never mentions spheres. I would guess the particles are cylindrical. Also pure iron has a permeability comparable to some ferrites.

Re:What about the RF characteristics? (1)

riverat1 (1048260) | more than 4 years ago | (#31376696)

Even a spherical piece of iron can have magnetic poles and will align along those in a magnetic field even though you can't really tell just by looking at it.

Re:What about the RF characteristics? (1)

derGoldstein (1494129) | more than 4 years ago | (#31375854)

It responds to a magnetic field, so it'll effect the inductive characteristics of the circuit. This would seriously mess up any high-frequency circuit. Unless you can "remove" the ferromagnetic element from the solder once you're done shaping it, this is a big hurdle.

Re:What about the RF characteristics? (1)

drerwk (695572) | more than 4 years ago | (#31377320)

Not likely. I assume the iron is heated by induction, which would be through a strongish time varying magnetic field. The field induces eddy currents in the iron, which has some resistance. The magnetic field that does this, will not be created be the current running through the solder joint, hence no heating, so the solder will not melt. Like wise, no reason to think the inductance will be anything other than that of a short straight wire.

Re:What about the RF characteristics? (1)

shiftless (410350) | more than 4 years ago | (#31379662)

I think what he's saying is that the altered inductive characteristics would need to be accounted for in the circuit, particularly in the case of high frequency stuff like RF amplifiers etc. It could be enough of a difference to require extensive changes to circuitry, but still, those kinds of components can continue to use existing soldering methods if necessary, so no big deal.

Re:What about the RF characteristics? (1)

drerwk (695572) | more than 4 years ago | (#31381534)

And I am saying I would be surprised if there was any important difference. We are talking about the interconnects between stacked chips; maybe 2mm in length. The conductor is a straight line - the lowest inductance geometry you could hope for.
Please give me any qualitative argument to support the claim that there would be a relevant change in inductance.

the real question (2, Funny)

jollyreaper (513215) | more than 4 years ago | (#31375190)

Will Microsoft install a magnetic field generator in the next Xbox to ensure the solder fails there, too?

Re:the real question (0)

Anonymous Coward | more than 4 years ago | (#31377422)

so what is the point of a jab at Microsoft????? Obviously, some sees MSFT in everything

Accidental reflow? (3, Interesting)

pavon (30274) | more than 4 years ago | (#31375204)

From the article:

A new type of solder can be melted and shaped in three dimensions under the force of a weak magnetic field

How weak are we talking about here? I wouldn't want my chips to become desoldered just because they were exposed to an electromagnetic field. The article didn't mention any thing about that.

Re:Accidental reflow? (1)

Carnildo (712617) | more than 4 years ago | (#31375316)

How weak are we talking about here? I wouldn't want my chips to become desoldered just because they were exposed to an electromagnetic field. The article didn't mention any thing about that.

It works through induction heating [wikipedia.org], which requires a time-varying magnetic field. It's perfectly safe to use refrigerator magnets to stick things to your computer case, but you might have trouble using these new chips in the computer's speakers.

Re:Accidental reflow? (2, Interesting)

X0563511 (793323) | more than 4 years ago | (#31375858)

Hmm. How would the solder bond to connections though? From what I'm getting from this, the solder (and just the solder) would heat up. Basically you'd get a blob of molten solder refusing to bond to anything because of surface tension?

(100% guaranteed cold solder joints, basically)

You could pre-tin the connections, but then wouldn't the solder just remelt (while the metal plating remains cold) and "ball" off?

Re:Accidental reflow? (0)

Anonymous Coward | more than 4 years ago | (#31375340)

If the soldering was done using this technique your chips would never get a good solder joint in the first place. Ever "cold soldered" (not heated a joint up enough)? Yeah, it doesn't work well - the solder doesn't adhere. Now, you can make up for this by heating the solder even hotter so it spreads its heat to the joint - but then you may as well have soldered the normal way.

Re:Accidental reflow? (1)

pz (113803) | more than 4 years ago | (#31375584)

If the soldering was done using this technique your chips would never get a good solder joint in the first place. Ever "cold soldered" (not heated a joint up enough)? Yeah, it doesn't work well - the solder doesn't adhere. Now, you can make up for this by heating the solder even hotter so it spreads its heat to the joint - but then you may as well have soldered the normal way.

Wow, talk about not getting it. The iron particles are inductively heated through an alternating magnetic field. They heat the tin/lead alloy through intimate contact. Heating is localized because (a) the iron particles are only in the solder mixture and (b) a good soldering design will have focused magnetic fields or magnetic shielding to ensure that heating is approximately limited to where it is needed. Eventually, the solder will reach the normal melting temperature but since heating is applied inductively (to which the iron particles are far more sensitive than most everything else in an assembled PCB), the heating is localized to where it is needed, rather than globally applied as is the case with solder wave bath, reflow ovens, and vapor-phase reflow, or semi-locally as is the case with hot air streams.

The interesting part of this technology will be to understand how it differs in implementation and efficiency from a decent focused beam IR method since it would seem to have the same advantages of localized heating.

Re:Accidental reflow? (2, Interesting)

moteyalpha (1228680) | more than 4 years ago | (#31375514)

What about -intentional- reflow. It would be useless for Mil Spec certainly and I would guess that war walking could take on a new level of meaning. It would be interesting if they used multipurpose dies that could be connected and recycled to a new configuration. Oh yes, liquid metal terminator brains. Mmm brains.

iron, huh? (3, Insightful)

metamechanical (545566) | more than 4 years ago | (#31375206)

The result is a tin-silver alloy that contains a dispersion of iron particles tens of micrometers in diameter.

Not saying it can't work, as the above is light on precise chemistry, but in an alloy like this, you're bound to have atoms floating around... say, to the surface of the deposition... where it will oxidize. And something like OSP [wikipedia.org] (which yes, wouldn't bond to SnAg) only lasts so long in storage... Don't we already have ENOUGH problems with solder joint oxidation? I look forward to seeing how this issue is addressed.

Re:iron, huh? (0)

Anonymous Coward | more than 4 years ago | (#31377994)

Electromigration might be an issue, as well.

Re:iron, huh? (0)

Anonymous Coward | more than 4 years ago | (#31378454)

If this guy has invented solder that turns stronger as it rusts then he's made lifetime impregnable solder that's like the original Blackbird. I would like to shake the hand of the daughter of the smartest man I ever met. Oops => overtones of Armageddon, overtones of Armageddon here! Rust enveloped computer circuits are harder than the damn asteroid, throw in another transmission.

What happens... (1)

grub (11606) | more than 4 years ago | (#31375248)


What happens if the finished product is exposed to a strong magnetic field? Does it all fall apart?

How small are the particles? (1)

dwiget001 (1073738) | more than 4 years ago | (#31375262)

I would prefer the iron particles to be exactly 10 microns in size, and not 10 micrometers, as it makes the process a whole lot cleaner....

Re:How small are the particles? (1)

Beardo the Bearded (321478) | more than 4 years ago | (#31375628)

"Microns" is the colloquial form of "micrometers". "Micrometers" is technically correct.

Re:How small are the particles? (1)

Obfuscant (592200) | more than 4 years ago | (#31376500)

"Microns" is the colloquial form of "micrometers". "Micrometers" is technically correct.

No, microns are one 10,000th of a centon, which is one hundredth of a hour.

Re:How small are the particles? (1)

rcw-home (122017) | more than 4 years ago | (#31377520)

No, microns are one 10,000th of a centon, which is one hundredth of a hour.

Just making sure I have this right - an eon is 2.718 hours?

magnetic field? (2, Insightful)

Lord Ender (156273) | more than 4 years ago | (#31375296)

When a magnetic field is applied to the solders [they heat up]

Not to be pedantic, but this is the Internet... They are applying magnetic flux to their solder, not just a magnetic field. A field doesn't impart any energy.

Re:magnetic field? (2, Informative)

metamechanical (545566) | more than 4 years ago | (#31375394)

When a magnetic field is applied to the solders [they heat up]

Not to be pedantic, but this is the Internet... They are applying magnetic flux to their solder, not just a magnetic field. A field doesn't impart any energy.

Perhaps true, but keep in mind that in the context of Solder, "Flux" [wikipedia.org] has an entirely different meaning.

Re:magnetic field? (2, Informative)

zippthorne (748122) | more than 4 years ago | (#31375468)

Neither does magnetic flux. Magnetic flux is a local property of the static field and not the same thing as EM flux. It was a good pun, though.

Re:magnetic field? (2, Informative)

TeknoHog (164938) | more than 4 years ago | (#31375516)

Magnetic flux is simply the area integral of magnetic field strength. You can't have one without the other. (For the pedantic, the integrand here is actually magnetic flux density, which is proportional to magnetic field strength.)

However, for inductive heating you need a time-varying magnetic flux, which in this case is probably achieved by varying the field strength. The field can still be aligned on an axis, so the method works anyway.

Re:magnetic field? (2, Informative)

wizardforce (1005805) | more than 4 years ago | (#31375956)

You can't apply a magnetic field to a material where a field didn't previously act without having the field intensity fluctuate (flux).

JB Weld (4, Interesting)

macraig (621737) | more than 4 years ago | (#31375356)

JB Weld contains so much iron particulate in suspension that it responds to a magnetic field. If it weren't for the fact that the particles are so much larger and get drawn out of suspension and toward the magnet, it might be possible to speed-cure the stuff with this same trick.

Re:JB Weld (2, Funny)

Anonymous Coward | more than 4 years ago | (#31376204)

If only there was some way to alternate the magnetic field...

But that's crazy Star Trek talk

Re:JB Weld (1)

macraig (621737) | more than 4 years ago | (#31376326)

Yeah, it is the stuff of Star Trek.. I'll use the deflector array! (Thanks for pointing that out.)

Re:JB Weld (0)

Anonymous Coward | more than 4 years ago | (#31376572)

Let me know when you can alternate a magnetic field between attracting iron particulate and repelling it. I want stock in that company AND the bungee jacket franchise.

Now magnets on both sides perhaps...

Seems to be based on core loss (2, Informative)

grimsnaggle (1320777) | more than 4 years ago | (#31375414)

Solder is already conductive, so the eddy current losses won't be localized in the iron particles. Further, copper traces are even more conductive.

This must be based on the hysteresis losses in the iron B-H curves. That means he's probably got a very high frequency magnetic field generator that he's using to heat up the iron. Seems like a simple principle.

That said, I still don't want iron filings in my solder!

Re:Seems to be based on core loss (1)

pz (113803) | more than 4 years ago | (#31375612)

Solder is already conductive, so the eddy current losses won't be localized in the iron particles. Further, copper traces are even more conductive.

This must be based on the hysteresis losses in the iron B-H curves. That means he's probably got a very high frequency magnetic field generator that he's using to heat up the iron. Seems like a simple principle.

Could also be from friction heating as the iron particles get moved around within the solder paste.

Dispersion hardener (1)

systemeng (998953) | more than 4 years ago | (#31375512)

This sounds like this would use a very high intensity high frequency magnetic field tuned to make the iron particles resonate and heat the material. I suspect it would be like normal solder with some iron particles. As a bonus, small iron particles would act a a dispersion hardener in the alloy. It's also quite possible that the particles are actually nanoparticles of iron rather than micrometer sized ones as this size range works better as a dispersion hardener.

How about damage to the chip (1)

aarenz (1009365) | more than 4 years ago | (#31375542)

This may work in testing, but does the field that is required to make the solder melt going to have impact on the very delicate circuits in a CPU or other chip. That is why the details are closed, because there are other problems.

All I have to say is.. (1)

Falkentyne (760418) | more than 4 years ago | (#31375588)

Viva la revolucion!


I also have to ask - what's with the revolutions today? It's Friday. Monday is the day for revolutions.

Impact on formation of Tin Whiskers? (1)

jr0dy (943553) | more than 4 years ago | (#31375656)

Anyone have any ideas as to what impact this may have on the formation of "tin whiskers"? Slashdot article on 6/15/08 re: Tin Whiskers [slashdot.org]

Re:Impact on formation of Tin Whiskers? (1)

mcgrew (92797) | more than 4 years ago | (#31375916)

You need tin to have Tin Whiskers. 100% tin ensures tin whiskers, which is why lead was added to the tin to make solder; enough lead and the whiskers go away. If you RTFS you'll see that there's no tin in this solder; it's silver solder, not tin solder.

Re:Impact on formation of Tin Whiskers? (1)

Sponge Bath (413667) | more than 4 years ago | (#31376586)

If you RTFS you'll see that there's no tin in this solder; it's silver solder, not tin solder.

From the summary: "The result is a tin-silver alloy..."
Sounds like tin-silver solder to me, which is common these days.

Re:Impact on formation of Tin Whiskers? (1)

ChrisMaple (607946) | more than 4 years ago | (#31380912)

Lead was added to tin to make a good solder long before sizes were small enough to make whiskers a problem. Lead-tin solders are close to the eutectic point, which makes them much easier to melt than either pure lead or pure tin.

No whiskering. (1)

OmniGeek (72743) | more than 4 years ago | (#31375924)

Tin whiskers only form in the presence of pure tin, as in a tinned PC board trace or component lead. Combine the tin with lead or silver or anything else, and the pure tin crystal structure won't happen, hence no whisker formation. Tin whiskers (dendrites) form when a layer of pure tin is mechanically stressed; the tin recrystallizes as dendrites in response to the strain on the crystal lattice. The recent increase in tin whiskering is due in part to hazmat-reduction regulations that discourage the use of lead solder, causing manufacturers to plate component leads in tin rather than lead-bearing solder.

Isn't that how we make cold joints (2, Interesting)

MarcAuslander (517215) | more than 4 years ago | (#31375686)

In soldering 101 I learned that if you put hot solder on cold metal, the solder doesn't really wet the joint, and you will get early or immediate failure of conductivity. You can even accidentally create a diode. So why will this work?

Re:Isn't that how we make cold joints (1)

Enleth (947766) | more than 4 years ago | (#31376042)

It is.

Either it's a bad case of lousy, pseudo-scientific journalism, or the people who invented this were not as bright as it seems. The invention itself is interesting and undoubtedly will be found useful for some very specific uses (molding microscopic parts, maybe?), but soldering electronics is not going to be one of them.

You just can't put hot solder on a cold contact or PCB pad and expect it to work. It will not. Soldering requires heating the surfaces being joined as well as the solder, to the same or even higher temperature (achieved by only directly heating those surfaces and letting the solder melt in contact with them). Period.

Re:Isn't that how we make cold joints (1)

Khyber (864651) | more than 4 years ago | (#31378274)

"Soldering requires heating the surfaces being joined as well as the solder"

Nope. Surface-mounting doesn't require this - there's a contact pad and you use reflux soldering or forced hot air to melt a solder paste. Things tend to slip right into place nicely and neatly thanks t surface tension.

Re:Isn't that how we make cold joints (1)

Enleth (947766) | more than 4 years ago | (#31379520)

As far as I know, the contact pads are still being heated because the processes involved in reflow and hot air soldering generate much "excess" (actually, not) heat around the solder paste itself and heat those pads, as well as the rest of the whole board, to a uniform temperature.

Besides, I can recall a technology that involved microwaving a board with a water-based solder paste on it and AFAIR it was said to be highly unreliable oexcept in strictly controlled conditions because of the pads not getting hot enough from just the heat of the paste - as the water evaporated, thethermal capacity of a paste glob decreses and soon there's not enough heat in it to maintain the temperature increase in the pad.

Re:Isn't that how we make cold joints (2, Informative)

mikael (484) | more than 4 years ago | (#31377136)

It's for use with assembly line surface mount technology [wikipedia.org]

The boards are then conveyed into the reflow soldering oven. They first enter a pre-heat zone, where the temperature of the board and all the components is gradually, uniformly raised. The boards then enter a zone where the temperature is high enough to melt the solder particles in the solder paste, bonding the component leads to the pads on the circuit board. The surface tension of the molten solder helps keep the components in place, and if the solder pad geometries are correctly designed, surface tension automatically aligns the components on their pads. There are a number of techniques for reflowing solder. One is to use infrared lamps; this is called infrared reflow. Another is to use a hot gas convection. Another technology which is becoming popular again is special fluorocarbon liquids with high boiling points which use a method called vapor phase reflow. Due to environmental concerns, this method was falling out of favor until lead-free legislation was introduced which requires tighter controls on soldering. Currently, at the end of 2008, convection soldering is the most popular reflow technology using either standard air or nitrogen gas.

The researchers are proposing to replace these methods with a high-frequency oscillating magnetic field that would heat the solder to melting point

Similar principle (1)

eclectro (227083) | more than 4 years ago | (#31375714)

Is involved with the metcal [metcal.com] hand solder station, with the twist that there are magnetic particles in the solder.

Iron Particles... <hmmm> (1)

FlyingGuy (989135) | more than 4 years ago | (#31375732)

Well ok, if the iron particles heat up that's fine it melts the solder. But after that I can't see them adding anything in the way of strength since last I knew, a solder joint was a Covalent Bond, not a mechanical one.

Anyone know if you can get a covalent bond between iron and tin/silver? The whole connection is based on the covalent bond between copper and silver/lead/tin. Not being a chemist I am not sure if these things matter or not.

Now the other part is, how does one keep said iron particles from getting between the pad and the lead? You want the thinnest solder joint between the two actual surfaces so if the iron particles ( yes I know they are small ) get between would that not weaken the actual bond itself?

I don't get it (1)

Rogerborg (306625) | more than 4 years ago | (#31377948)

The kdawson scripts posts the vapourware snake oil shill press releases. What's the ScuttleMonkey script doing muscling in?

Useful in phase-change memory manufacturing? (1)

the_olo (160789) | more than 4 years ago | (#31401938)

AFAIR, a major problem before phase-change memory [wikipedia.org] can become a flash memory replacement is its sensitivity to heat and the resulting modifications that producers would have to introduce to their manufacturing processes (e.g. putting data on the memory chips after, not before assembling).

Would this technology lift this requirement from them by lowering the tempeartures involved in the soldering process?

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