Read an interesting article tonight about the implications of removing lead from solder to keep it out of our landfills. It seems that lead was alloyed with tin in solder in the first place to prevent "whiskering", where small hairlike filaments naturally grow out from the surface of the soldered joint, similar to rust or other corrosion. It's not completely understood why tin and a few other metals used in soldering do this in the first place, but alloying the metals with lead eliminates the problem. When the whiskers grow long enough to come into contact with the nearest neighbor's soldered joint on a circuit board, it results in.. yep.. a dead short. Seems the problem affects most of the alternative alloys proposed or mandated by "green" legislation in various countries (including the United States, most recently). So the price goes up and the MTBF (mean time between failures) drops to half that of things made with lead based solder due to whiskering. Just a heads up- it will be interesting to see in the coming years how this affects the work we do .. commerical lighting control boards come to mind, as well as the myriad types of dimmers, photocells, and various other devices we work with. It will probably take a good year before the existing stock of products made with leaded solder are sold off the shelf and all that is left are products made with the new lead free alternatives. I suppose it will become a script we have to memorize, explaining to customers why their expensive electronic device failed so quickly. Whiskering also begins from the time of manufacture, so maybe we will need freshness dates on the things we buy, similar to milk, cheese or beer.

A link to a NASA article on problems they have had with whiskering
and some good pictures of what it is and what it looks like:

http://nepp.nasa.gov/WHISKER/

http://nepp.nasa.gov/WHISKER/reference/tech_papers/2007-brusse-metal-whiskers.pdf

Wikipedia article on whiskering, including what metals/alloys are most
afflicted by it:

http://en.wikipedia.org/wiki/Whisker_(metallurgy)

Time will tell... leaded solder was banned from commercial use in the EU at least one year ago and so far I haven't heard of a spectacular rise in equipment failures. I do know development of new technologies was problematic at first, but it seems to have worked out by now (I know a bunch of people whe experimented with lead free soldering of photovoltaic cell and concluded proper flux is the key to success.)

Tin whiskering isn't the only problem with the new solder formulations. The lead-free alloys tend to be much more brittle than the standard Sn/Pb solder, and the joints tend to crack with repeated heat/cool cycles. The problem is exacerbated by the use of surface mount components, which have no wire leads to absorb the stress.

Microsoft is learning about this the hard way with massive field failures on their "X-box 360" videogame systems. The lead free solder joints are failing, prompting LOTS of warranty repairs.

Conventional tin/lead solder can still be sold here for "special" purposes, so fortunately those of us who want to keep on using it for repairing vintage radio equipment are still O.K. for the moment. It's getting harder to find sources though.

If they ever decide to completely ban lead in solder, I think we'll be back to stockpiling as much as we can afford. Better make room alongside all those boxes of filament lamps!

Pardon my ignorance, but isn't lead found naturally in nature? It seems to me that there's no more or less lead around whether some of it's made into solder or not.

Public preception is more important then reality

Tell that to home inspectors and their clients...

Ian (Surrounded by asbestos) A.

I think this became an issue when people started realizing the impact of throwaway electronics. Nobody fixes anything these days, you throw it away and buy a new one so a lot more lead is finding it's way into the waste stream. Unfortunately some of these widgets are not even lasting long enough to survive their short design life

How many kids a year do they figure chew on circuit boards anyway?

Unfortunately, with the reliability problems caused by the lead-free solder, there will probably end up being even MORE junked electronics headed for landfills in the future. If the manufacturers can get the solder joints to hold together long enough to get through the 90 day warranty, then failures after that just help ensure the sale of MORE cheap Chinese TVs and DVD players.

Wait until analog TV goes dark in the US next year--the curbsides are going to be flooded with discarded sets...

I'm still looking for an affordable replacemenet for my 1.8" LCD TV. What am I going to use next hurricane season? I can't exactly use a converter box for a TV that runs on AA batteries

I imagine there will be someone with a battery powered converter. I ordered a coupon for one of the regular converters anyway, I figure it will run fine from an inverter but I will probably be opening it up to see if it doesn't run on one low voltage DC supply. It might be as simple as a 3 terminal regulator and a DC coax plug (maybe just the right battery).

Well, I do have a generator now, so we can always fire up the 65" HDTV, but if it's a wide outage, cable will likely be out, and we don't have a decent antenna for it. And we probably won't be running the generator 24/7, either. Luckily, I've got internet on my cell phone, and we have laptops and a small inverter, so that much is covered.

That little 1.8" is just so nice to toss in my pocket and watch the game at the park while the kids are playing, etc, in addition to actual emergencies. It's a shame, too- it's made from quality lead solder and would probably have lasted a few decades.

From what I have seen of over-the-air digital TV, the converter box users are going to have problems of their own, particularly in fringe reception areas.

While a weak signal on analog TV will result in snow or occasional picture tearing, the picture and sound is at least somewhat usable even down to quite low signal levels. A signal below a certain critical level will give you NOTHING on a digital setup. If the signal fades in and out, it is like trying to watch internet streaming video over a dialup connection. Constant pauses and dropouts in picture AND sound.

The converter boxes are going to be designed and built to a price point (however much the government subsidy is--$40 per box, IIRC). To cut costs, extra RF gain stages and other "frills" that mike make the things useful in fringe areas will probably be the first things chopped out.

All the noise your hearing on the TV about the comming change. is the cable, and satellite companies, hoping you will be unhappy with the converters, so they can snag you in as a customer, In my opinion, this is just another goverment helping, the communications giants.

Ha, who is going to lobby for us.

Steve, your right, a lot of people will miss their 1.5".

Digital TV is being pushed heavily here as well, and analog shutdown is due to take place region by region between the end of this year and 2012. A lot of people will need to invest in better antenna systems, as while they seem quite happy to watch through a little snow, they're not going to take to the blocking and freezing effects with marginal signals on digital.

Given a good signal, the digital pictures we get here are good. The main problem I've experienced -- both on my own digital converters and with those I've seen elsewhere -- is that some of the software is so full of bugs that it would take a barrel of DDT to expunge them!

Far too many of the receivers lock-up on a whim, go part way through a timer program and then suddenly there's no video, or a frozen frame even though the signal is fine and sound continues perfectly, etc. Regular reboots are the order of the day.

Exactly what I heard...

We have satellite anyway, so the only person noticing the analog shutdown was yours truly... and I simply stopped watching TV. I think the only time I watched TV during the last year was when my girlfriend wanted to wtach one special dance show with me. That was one evening in a full year.
Now I only use my TV as a video monitor.

My late 1950s TV is unuseable now... it's only got VHF reception, so not even a chance to use it with a converter box with RF output.
I havent used it for years anyway since I suspect faulty capacitors but don't feel confident working on a TV set (so far my electronis experiences have been limited to minor solid state work under close supervision).

Everything's going to be streaming video through the internet soon, anyhow. Cartoon Network has been a real leader with this respect; they have nearly their entire late-night "adult swim" lineup free for download online- watch one commercial, and the whole show streams to you whenever you want. Quality is very good, too, and a lot of old shows are archived.

http://www.adultswim.com if anyone cares to check it out.

I think the internet and the DVR are the perfect match and really the way TV is going to go. With a DVR you could cache the shows during slow times on the internet to watch at your leisure. It avoids the bandwidth problems of millions of people trying to stream a lot of different shows at the same time. You could select from a catalog and get them shipped on the next scheduled time or pay a little more to get them right now.