Lead free solder - exposed in a UK national newspaper

From you, that's a supreme compliment.

Look in the mirror, Dimbulb.

IKYABWAI

--
Keith

For street lighting, warehouse lighting, and industrial lighting there is a competing technology: Induction lighting. Typical lamp/bulb life

50,000 to 75,000 hours. Twice the life and better luminous efficacy at a 50% surcharge compared to HID lighting. It is starting to get a lot of notice. Oh, and better electrical efficiency, takes about half the power for the same amount of light.

I don't know how much take-up of this technology there has been in the UK. It does beg the question of how much trouble it could cause, if a single streetlamp or warehouse luminaire went 'rogue'. Already, I see fellow hams bleating all the time about HF bands interference problems from rogue CFLs, and SMPS's and PLT and so on. Imagine the potential for interference if a high power streetlight ballast, feeding an induction lamp 50ft up a pole, started radiating on 13 odd megs. Or a factory one 50ft up in the ceiling ... :-)

Arfa

more printed followup

# The Guardian, # Thursday April 17 2008 Tin woes solder on

Congratulations on the very interesting article on tin whiskers (Within a whisker of failure, April 3). You may be interested to hear of another phenomenon associated with lead-free solders in electronics, known as tin pest. Research was carried out into the allotropy of tin 80 years ago. Tin pest was found to occur by a process of nucleation and growth of "grey" tin (a form found below 13C), and was very slow - often requiring years to complete. Since the transition from "white" to "grey" tin involved a 27% increase in volume, its formation was restricted to the surface. Recently, tin pest has been reported in bulk samples of lead-free solder alloys following a few years' exposure at -18C, the usual freezer temperature.

To date it has not been observed on actual joints. But lead-free interconnections have been in service for a relatively short time. Although we do not know whether it is necessary to shut the stable door, we should make more effort to understand and control tin pest formation. Only time will tell whether it represents a real problem in electronics. Professor Bill Plumbridge Faculty of Technology The Open University

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

In the US they have to meet FCC radiated and conducted emission standards. Thus the CFLs going rouge probably only statistically meet those standards, such is part of the nature of regulation.

They have to meet strict emission regulations here too, which I'm sure for the most part, when in full working order, they do. The problems arise when the crappy little filter caps in the front end of the switching driver for the tubes, go open circuit or high ESR, due no doubt to the unventillated enclosure in the bottom of the lamp, that the electronics sit in, running very hot. Once that cap has failed, the inverter radiates like a bastard, swamping the airways with broadband hash. It's bad enough when one goes rogue like this, 6 foot off the deck in someone's driveway light outside their house. Think what it would be like if one went bad 50 foot up in the air ...

Arfa

'Plumb' -ridge. What an appropriate name for someone versed in lead matters ! Seriously though, I'm really glad that the scientific establishment is finally making some anti lead-free noise, and backing up with genuine science, what we lowly service engineers have been trying to tell the world, since the first day that this hateful material was foisted on us by self serving bureaucrats with a politically 'green' agenda ...

Arfa

Please explain under what situations would a cfl be mounted 50 feet above ground.

Block of flats ? Might be 100 feet up in the air or more in that case. When the EU morons responsible for all this eco-bollocks legislation finally ban incandescents in the UK, as they have stated that they will in short order, then tower blocks will be full of CFLs, as there will be no alternative, yes ?

Originally, when we got onto lighting being 50 foot up in the air, we were talking about induction lighting in street lamps and factory ceiling lights. The point was that these devices use high frequency generators to couple the energy into the lamps, and these generators follow similar design principles to the tube driver inverters in CFLs. Thus, if low power CFL inverters go bad, and create the RF havoc that they sometimes do at just a few feet off the ground, then imagine how bad the situation would be if the high power HF generator for an induction lamp, 50 foot up a pole, when similarly bad. With my thinking now ...?

Arfa

Most of those will be converted to HID lighting or induction lighting instead of cfl over the longevity characteristics.

?????????

Arfa

Most street lighting is HPS currently with a normal ballast, there are some MH lamps with normal ballasts. LED street lighting is being experimented with. Caltrans in using induction lighting on signs and may branch out into other uses. Since induction lighting is targeted at hard to maintain locations in commercial and industrial settings there are design differences from household CFL where cheap is the dominant factor. Where we will see CFL is on smaller apartment buildings with penny-pinching owners / managers.

Ah, OK. I see what you're saying now. I guess that LED lighting is going to become the standard when they can get them high enough powered. This can't be too far away, as I see that car manufacturers are starting to experiment with LED headlights. Already, Audi seem to have LED front running lights, set into the headlight units, and some of the front lamps used on bicycles now output enough light to see the road ahead. A local night club had coloured floodlights on the front of the building, which were LED based, and I was amazed at just how good a job they did.

Elektor magazine carried out an interesting project last month. They took a DLP video projector with a standard expensive HID lamp and colour wheel, and canibalised it to fit an array of red, green and blue Luxeon LEDs in its place. They then programmed up a cheap microcontroller to emulate the rotation of the colour wheel, by switching the colours of the LEDs with 3 FETs. They also fed a colour sync signal from the micro to the original optical sync pickup, so that the LED switching remained synced to the DLP chip drive. Colour balance was achieved by tweaking the 'on' times of the LED colours, in software.

The conclusion was that although not as bright as the original HID lamp, the projector did produce a perfectly useable picture, which proved what they set out to, which was that it was perfectly possible to use LEDs in place of a lamp, and that it would be just as good, once they had got the luminous output up just a bit more.

Arfa

and some balancing comment

# The Guardian, # Thursday April 24 2008 A whisker of doubt

I believe there are several inaccuracies in Kurt Jacobsen's article (Within a whisker of failure, April 3). He cites the Swatch watch company as recalling a "huge batch" of watches that amounted to a financial loss, when in fact Swatch was denied its request for a RoHS exemption, as another supplier makes lead-free quartz movements it could use with no whisker issues. Also, Swatch makes no mention of a recall in its EU request. The nuclear power plant failure example and others are also misleading, as these were failures due to pure-tin formulations that predate RoHS. The new formulations reduce these issues. Here's a good article that refutes the "gloom and doom" predictions: tinyurl.com/4wxmkz. Marcus England, by email

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Hmmm. Have you ever come across any solder that's pure tin ? It would take a blowtorch to melt it. Also, there is plenty of research that shows that the lead in tin-lead solder alloy, mitigates the growth of tin whiskers, whereas copper doesn't. And anyway, none of the whisker issues alter the fact that the bloody stuff just doesn't make reliable joints on many component forms, as anyone involved at the sharp end, would attest to ...

The article that Mr England cites, does not instil a great deal more confidence in me. Whilst it may be true that *some* cellular phones have been manufactured in lead-free since 2001, this 'fact' tells us nothing about the long-term reliability of them, as most are owned primarily as a fashion statement - even amongst 'mature' businessmen - and only secondarily as a communications device. This, as well as the fact that the battery only lasts a short while, dictates that it is replaced on a yearly basis, which is encouraged by the cellular operators, when they give the latest all singing and dancing models away, as an incentive to stick with their network.

Further, this is just one single low power device, As all of us involved in electronic service work know, there are many other consumer devices such as TV sets, DVD players, HiFi, microwave ovens etc which, unlike cellphones, contain large power components and connectors, which do not enjoy good long term - or often even short term - reliability, when jointed using lead-free solders. This in no way supports the statement in the article that :-

"This field data indicates the reliability of lead-free assemblies is equal to, or better than, tin-lead soldered assemblies".

You simply can't make statements like that based on a single product group, and claim them to have blanket validity.

The further statement ....

"While laboratory studies suggest lead-free solder does not perform as well in high-stress applications, such as might occur in a ?drop test', many applications with these types of concerns (i.e. military) are currently exempted from RoHS. Meanwhile, alloy developmental work to address lead-free shortcomings is already underway."

.... contains three areas of concern in that (1) lead-free solder does not perform *as well* ... (2) some applications e.g. military have concerns about this, and (3) that it is accepted that the technology has shortcomings that need to be addressed.

Further, I also have a problem with the first paragraph in the article :-

"Most people incorrectly think the primary intent of RoHS is to protect the environment. In truth, the fundamental purpose of RoHS is to make recycling EEE easier and safer."

Protection of the environment was the ticket on which RoHS in general - and this substitute lead-free technology in particular - was originally sold to an unsuspecting world. It seems to me that those who make up this eco-legislation (as they go along, I suspect) are now discovering the error of their original concept as to why the mature and proven lead solder technology needed replacing, and are now seeking to bury that error in a different concept altogether. I can't remember ever before seeing any reference anywhere to RoHS being primarily to improve the ease and safety of WEEE recycling, rather than as an environmental issue.

So, far from this article "refuting the gloom and doom", I think it serves only to further highlight the well known shortcomings of lead-free solder technology, and unfortunately for Mr England's case, I don't believe that his letter holds a candle to the two from the other side of the coin, which preceded it.

Arfa

and

to

error

of

which

What exactly can be recycled from say a PC? As far as I can see the steel casing and perhaps some copper if it is not too widely distributed , fragmented, needing human separation and plastic separation environmental problems. RoHS for recycling implies component level recycling - recycling 3 to 10 year old pc ICs - pull the other one. Failing that, recycling processed sand and hard plastic after desoldering, very unlikely. Leaves just the solder itself, which is just as recyclable with or without lead presumably .

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

That would appear to me to be the nub of the matter, so it sounds as though you agree with me that this 'ease of recycling' thing is a subtle shift of tack to better handle the changing wind direction ...

I know that they do recover gold from gold-plated connectors and IC pins, but other than that, I agree that there's not a lot that can be recycled from a purely practical point of view in terms of cost-effectiveness, both from purely monetary and energy budget considerations.

Arfa

A couple of microns ?

Since when have "IC pins" had gold on them ?

Indeed and it seems almost no-one in Europe wants to touch the stuff. Trying to 'recycle' electronics pcbs strikes me as an utter waste of time. What do end up with of any use ? Nothing !

Graham

Since they put about a million of them on the bottom of a big chunk of ceramic, called it a processor chip, and then tried to persuade all those pins to make a good electrical connection via a ZIF socket ...

I saw a TV programme about a facility in the UK that recycles computers, and removes the gold from various bits and pieces at a 'secret' location, and I was astounded by the amounts of gold that were recovered, that not only made this worth it from a recycling point of view, but also extremely financially lucrative for the company doing it.

Take a look at this link for more facts than I could give you

Arfa