RoHS

Well, I dont have any account of FPGA problems, but you have to be ready for trouble when it comes to fabrication, and pcb design. PCB material has to change to meet the new standards (RoHS is not just about lead) New materials = New impedances... High speed designs might depend on certain track impedances, and if you try and port an old design to the new process - they won't match! Then there's the problem of finding _ALL_ components on your design in a RoHS version... and finding RoHS solder, and then putting it all together. A soldered joint that has been made with a RoHS process looks different to a traditional joint... so good joints might be flagged as bad etc etc. Anyways, I don't have FPGA specific comments, but obviously the FPGA is going to be on a PCB with other devices. HTH Ben

There is no way around RoHS compliance, at least over here. There are some exception for certain industries. Unless you belong to them, You just have to make it work. The exception are being constantly reevaluated. So if your competition can make it work without lead, you'll be out soomer or later.

Rene

--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

To expand on Rene's comment, there's no way around RoHS compliance

**anywhere**. Molex, for instance, has obsoleted all it's high density parts (to my knowledge) in favour of new RoHS compliant parts. They are probably doing this across the board, as they don't want to keep different stocks on hand with the logistics nightmare involved.

As to high speed problems:

Different materials will undoubtedly cause impedance vectors to change. In addition, the loss tangents across materials (very important in extremely high frequency designs) will vary. Whether they will be better or worse is unknown, but after all the research into existing materials, my take is they will be worse.

IC packaging will have to change. Most existing plastic packages have absolute maximum temperature ratings of about 220C, but the RoHS reflow profile is well above this (about 260C). See this Xilinx app note:

Changing the materials to make a device compatible with those reflow characteristics is bound to have an effect somewhere, although I don't know the specifics for Xilinx.

In addition to that, the solder joint of a tiny part (such as a coupling cap) has parasitics that are (somewhat) material dependent. Change the materials, change the parasitics. This too is an issue for high speed designs.

Note - when I mention extremely high frequencies, I am referring to bit times (on the wire pair) of 1nSec or less (PCI express, InfiniBand and Fibre channel come to mind).

So will it affect us in high speed designs? Undoubtedly.

The issue is we probably won't know the effects until there are large numbers of boards already made.

Cheers

PeteS

PeteS wrote: [snippage]

The thermal resistance will also be different. (I don't know whether it will be better or worse, but Murphy says it will be worse.) A significant amount of heat leaves the package through the balls, and this may matter for high speed designs.

Regards, Allan

..A significant amount of heat leaves the package through the balls, and this may matter for high speed designs. ...

Very true (not so much if it's a flipchip ;)

It will most definitely change the thermal characteristics. That being the case, we'll either get poorer guaranteed performance, or poorer temperature ranges. I'd take the termperature range and cool it (of course, that adds a whole new dimension).

Cheers

PeteS

Long term, yes. But, I'm not sure that I agree in terms of a mid-2006 hard deadline (which is a ridiculous idea IMHO).

As a small manufacturer, if I have to choose between a potential support and reliability nightmare from a shift to RoHS and simply not offering affected product in the EU, I'd go for option #2. New designs can be executed for RoHS compliance from the start, but few small to medium manufacturers are going to go through the trouble, expense and liability of redoing whole product lines unless a non-trivial portion of their business is in the EU. While the EU is an important market, the potential downside of a hasty transition is significantly more severe than the alternative.

Logistically, we've seen billion-dollar companies who supply us with components tell us that they will not have RoHS compliant parts available until "sometime in 1Q06". Clearly, migrating a design to RoHS parts in haste --with barely a few months of testing before shipping-- would be a horrendously bad idea.

My prediction is that the EU will have to soften the rules a bit because a full transition to 100% compliance by all entities that move product into the region is quite literally impossible. Few legislated hard deadlines, such as this one, ever execute exactly as written. Logistically, it is impossible for the EU to even approach the orders-of-magnitude in potential regulatory work that this will create. The whole thing, if executed by the letter of the law, could be quite damaging to business in general. Something's got to give. Or not. Who knows?

It'll be interesting to watch.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Martin Euredjian eCinema Systems, Inc.

To send private email: x@y where x = "martineu" y = "pacbell.net"

Remember there is quite a lot of stuff, especially the sort of things that big FPGAs go into, that is currently outside the scope of Rohs - this has not been well covered in the press. Included categories consumer electronics, household appliance, IT/telecom, toys or tools, so most test/lab type equipment is not covered. There are also currently specific exemptions for network infrastructure, and servers

Source :

It's worst than this. The press has little to do with it. The standard itself is nebulous and inconclusive. Some aspects of it are almost comical (no formal way to ascertain compliance...but you can go to jail and be fined up to UK$5,000 for a violation).

The real problem is that it has setup a "pass the buck" scenario, as we say on this side of the pond. Resellers ask distributors, who ask manufacturers who ask component manufacturers, for RoHS compliance guarantees. The lack of clarity and apparent intransigence of the system makes resellers and distributors fearful of anything other than "yes, absolutely, it is RoHS compliant". There is no amount of technical maneuvering that can convince someone in fear of a stiff fine and imprisonment that anything other than total compliance is safe.

Again, it'll be interesting to watch and see what happens come the middle of next year.

To be on-topic. It took our very large distributor almost a month to come up with an RoHS-compliant part number to replace a Virtex 2 we've been using in a design for a couple of years. It surprised me that it took that much work.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Martin Euredjian eCinema Systems, Inc.

To send private email: x@y where x = "martineu" y = "pacbell.net"

and there are more escape clauses appearing, as they realise the silliness of some of this :

eg from the last link "..and any lower melting temperature solder required to be used with high melting temperature solder to complete a viable electrical connection."

Seems now 'viable connection' and reliable operation are being recognized - someone must have pointed out that lead-free may reduce safety !

Perhaps if you are unable to _prove_ you have a reliable/viable electrical connection ( and that includes thermal cycling stresses and fatigue failures, over time ) then these escape clauses now apply ?

Amazing to see light bulbs exempt - given their short life spans, and direct waste flows, shouldn't they be first in the line ?

-jg

While I generally agree that reduction of waste and hazardous substances is an important goal for all of us, there's this thing I call "sense of proportion" that seems to get lost when politicians and special-interest groups get ahold of ideas. Europe is perplexing to me in many ways. While I admire the fact that they got it absolutely right on so many fronts, it is amazing to me that you can't walk into a restaurant in the dozen or so cities I've been to without walking away with lung cancer. Or, that, for example, concepts of safety seem completely foreign in some areas (don't take your kid for a tour inside of a windmill in the Netherlands unless you are ready to watch'em like a hawk --no safety barriers between little hands and huge gears!).

Anyhow, like I said, I think RoHS will be interesting to watch. Good concept, but hard deadlines, stiff penalties and horrendously fuzzy --and shifting-- regulations sure set the stage for a commedy...or a tragedy.

Again, trying to be on topic, I guess the message is that there is no real data on the long-term consequences of converting non-trivial designs to RoHS. What approaches are large companies taking to testing such designs after conversion? Accelerated aging, mechanical robustness, signal integrity and other issues come to mind.

To add to this, I've seen power supply manufacturers' eyes glaze over when RoHS is mentioned. Nobody wants to deal with this thing unless they absolutely must.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Martin Euredjian eCinema Systems, Inc.

To send private email: x@y where x = "martineu" y = "pacbell.net"

Great! I didn't know about that one! Of course, there's the biggie, namely Automotive batteries. A typical consumer electronic product with a modest PC board in it has, perhaps, a couple of grams of solder in it, and maybe half that by weight is Pb. So, maybe only one gram of lead! The product may last 5 years or so.

A typical car battery has 15 - 20 **KG** of lead in it! Yes, as a rule, car batteries are recycled, but certainly in wrecks, the battery may be destroyed, with plates and acid dripping out on the ground. It doesn't take too many wrecks where a battery has been smashed to equal the lead in a whole warehouse of electronic gear!

Well, I guess I'll have to figure out the Pb content of the typical light bulb. These CERTAINLY are going in the trash, too! (They probably don't even sell burned-out bulbs in Russia anymore [for surreptitious swapping by office workers, if you are wondering why there was a market for them.])

Jon

Frankly, I wish I could hope this RoHS madness will somehow die away... Such nonsense. Why don't we give up using silicon (might result into too much sand in Europe and turn it into a desert...) or any metals (too many potentially injuring sharp edges ) etc. etc., I guess we all can go on.

It is really good they have set their targets non-achievable. However, I would expect the right companies will somehow meet the (duly modified in the last minute) criteria... As usual, we should follow the money if we would want to know what is this all about.

Dimiter

------------------------------------------------------ Dimiter Popoff Transgalactic Instruments

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Didn't you realize that lightbulbs are slowly becoming out of fashion ? Where reliability matters, such as in traffic lights, they already have been replaced by LEDs.

LEDs take giant leaps in terms of brightness and cost, Together with rising prices for power, it won't take a decade to replace most light bulbs.

Rene

Rene Tschaggelar wrote: : LEDs take giant leaps in terms of brightness and cost, : Together with rising prices for power, it won't take : a decade to replace most light bulbs.

LEDs are still not as efficient as some more traditional light sources. Here are some approximate figures:

White LED: 25-40 lumens/Watt Fluorescent: 40-90 lumens/Watt HMI: 70-100 lumens/Watt

The LED figures are a few months old so there may be better ones now.

Richard.

To reply by email change 'news' to my forename.