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Researchers Getting the Lead Out of Electronics
alphadogg writes "Researchers at the University of Maryland say they have discovered a material to replace lead, a potential environmental hazard, in electronics products. The material, bismuth samarium ferrite (BSFO), was found by researchers in the university's A. James Clark School of Engineering. It can be used in products such as biomedical imaging devices and inkjet printers, and if implemented commercially could keep lead out of landfills and the ecosystem, they say. While manufacturers have developed replacements for lead in many products, until now no commercial replacement existed for lead zirconate titanate (PZT) — the material of choice for transducers, actuators, sensors and microelectromechanical systems used in common electronic devices, the university says."
Could this new metal shield against cosmic rays as well as lead? I'm reminded of the scene in Kim Stanley Robinson's Red Mars where the inhabitants of a spacecraft have to hold out against an incoming solar flare and find their shielding woefully insufficient. A material that could block rays yet be lightweight and less toxic would no doubt be a boon to the space industry.
So... have they actually tested this on humans to verify it's non-toxic? That's great that we're not using lead, but if this is just as bad for humans when it hits our water supply, what exactly is the benefit? Swapping one (cheap) poison for another (expensive) one?
Bismuth isn't radioactive
Lead: Found in damn near every kind of mining ore. Very common.
Bismuth: 2x more abundant than gold. Not considered economical to mine for it; Usually had as a byproduct.
So sure, if you want your production costs to go up up and away, killing your competitive edge, use the eco-friendly BiFeO3. Everyone else, keep pushing recycling and consumer awareness. -_- Oh -- and the icing on the cake? Guess who produces most of the world's bismuth? China, the country best known for producing lead-laden products of much doom.
#fuckbeta #iamslashdot #dicemustdie
While it's good that they're getting lead out of toys, etc. what about computers, televisions, and other devices/appliances which are generally not regarded as disposable? Is this new solder going to be more reliable than tin, which is notorious for whisker and dendrite formation, which wreaks havoc with reliability?
Given that you're on /. I'd assume that you know what tin whiskers and dendrites are, but in case you're not here is a refresher:
http://www.siliconfareast.com/whiskers.htm
You can see where this is a problem. And, although it's been discovered that matte tin surfaces and good quality control can reduce the likelihood of whisker formation, what about repairs and installation/reinstallation of components on a mainboard? Replacing integral components (capacitors, sockets, etc.) require high heat, which is sufficient to change the crystalline structure and introduce new stress points for whiskers to "grow," and flexing of the main board from installation of peripherals, connecting devices to sockets, and simple heat/cold cycling will be enough to introduce stress points even in properly-formed, properly-plated components, creating points where whisker formation is more likely.
Yes, protect the environment, but since more and more electronics are being recycled rather than being dumped in landfills, isn't lead in electronics a non-issue anyhow? I mean, in most localities you're not supposed to chuck monitors and devices containing printed circuit boards in the trash.
The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
As a technician, RoHS is the bane of my existence. It doesn't flow right, it doesn't wet right, and it doesn't cool right.
Because RoHS solder is not a true eutectic alloy it tends to separate when thermal conditions aren't precisely right. As a consequence, many manufacturers had huge runs of products that stayed soldered just long enough to get out the door and frequently out of warranty.
I hope someone comes up with a better substitute soon because I am sick and tired of cracked solder, cracked solder, and cracked solder.
Women are like electronics: you don't know how damaged they are until you try to turn them on.
From the same wikipedia article that was linked to (it's even in the first paragragh!):
A quick search came up with one site listing the cost of Samarium as $130 per 100g. I'm sure that's cost effective for medical imaging equipment. And I had never realized this, but our local landfill is positively brimming with discarded medical scanning equipment. I might try to scavenge some of this, but all the discarded MRI machines are clumped together by some unseen force.
FTFA, The researchers have found a replacement for Lead zirconate titanate not LEAD. PZT is a piezoelectric material that contains lead and is used to make actuators and transducers in microelectronics industry. The article itself is pretty poor describing piezoelectric materials as a "switch", so perhaps it is not the fault of the readers for thinking this was a replacement for lead based solders.
I've never seen a justification for the huge amount of money that's been spent on removing lead from electronics. Yes, the stuff can be toxic if ingested in sufficient quantities. No, it isn't going to leap out of your old TV set and perform unnatural acts on your dog. Tin-lead solder has been used for many decades. It's cheap and it works. I can understand why lead was removed from paint and gasoline. It was creating real problems when used in those products. Why, other than catering to the irrational and unfounded fears of the public, are we removing it from electronics?
Mea navis aericumbens anguillis abundat
The researchers haven't come up with "a material to replace lead." They've come up with a material to replace lead zirconate titanate, a.k.a. PZT, a piezoelectric and ferroelectric material with many uses in electronics. Because it has an extremely large piezoelectric constant (meaning that it produces a large voltage under little mechanical stress) and is cheap to produce, it is the ceramic frequently used in transducers, sensors, and resonators. The thing on your motherboard that beeps on boot is very likely made of PZT.
PZT is not, repeat not, used in solder. Wikipedia is one of your many friends.
Finding a ceramic with similar properties, but without the lead, has been a difficult problem for materials scientists, and the UM researchers say they have finally come up with a viable candidate.
You've got to love an environmental measure that ensures a significantly higher failure rate in electronic devices, meaning more electronics to trash -- electronics containing materials much more hazardous than lead. Sheer genius.
People in first world countries have so little to worry about in terms of health issues that they strain to find bogeymen, and lead has become one of the things filling that role.
I had one couple fly up from Texas just to see my house in Seattle, make an offer on it, and later rescind the offer because the house was old enough that it existed when lead paint was sometimes used. There was no specific reason to believe the paint was lead-based, and much of the house was wall-papered. The mom was terrified of the possibility of lead and her email withdrawing the offer was filled with heartbreak because they really adored the place; they ended up getting a recent townhome in a much less desirable location. One twist: they knew from the beginning that the attic had loose-fill vermiculite that had a decent chance of containing asbestos, and they had no problems with that.
As an engineer working on lead-free solder development for electronics, the problems that can arise are specific to the application. The industry has developed a number of different alloys that perform under specific conditions. Instead of just choosing a tin-lead solder that works pretty much everywhere, developers need to understand the types of reliability stresses their product will see and choose the best alloy to meet those requirements. For example lead-free solders that work well in a thermal cycling environment tend to not perform as well under shock conditions. From an assembly side of things, a lot of the problems arise from using old SnPb equipment and materials for soldering joints using leadfree solders. Different reflow temperatures, wetting characteristics, and oxides, means that you just can't use the same old eutectic flux and soldering iron and expect the same quality of results.
Lead-free solders aren't necessarily problematic, they just require a little more understanding to properly use.
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".....could keep lead out of landfills and the ecosystem, they say."
-Because everybody knows lead isn't from the environment.
Knowing Google's lust for data collection, the Soviet Union is still alive and well inside the psyche of Sergey Brin....