OT: RoHS and Lead?

Excuse the OT post, but I figured people in this group may have an answer for this odd question:

In transitioning to RoHS, can you mix Lead-free parts into a standard PbSn process? The idea is to start buying RoHS parts while depleting the existing stock of PbSn components.

Good? Bad? Ugly?

Thanks,

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

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

Reply to
Martin
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Martin,

Ugly, I am told.

Because of the temperature differences, there can be some real reliability problems (cold joints, or no joints).

My best bet is to tell you to contact the RoHS solder suppliers. Those guys are the ones that have to make a living doing it, and their presentations (in my experience) are absolutely the best ones.

For example:

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Aust> Excuse the OT post, but I figured people in this group may have an answer

Reply to
Austin Lesea

"Martin" wrote in news:XiBxf.287$ snipped-for-privacy@newssvr12.news.prodigy.com:

You are going to have no real problems soldering leadfree parts with tin- lead solder. The big exception to this are BGAs. The ball of a BGA is solder. If it is leadfree, it will need to be soldered at a higher temperature. You CM will need to know this.

Many parts have been supplied leadfree for several years. This includes many of the passives that you probably are already using. They might not have been labeled as such.

We have started using lead free pcbs as well. In our case we have opted for ENIG (electroless nickel/immersion gold). They are easy to solder with PbSn

No one really knows the long term effects of moving to RoHS. I am hoping that the EU decides that July is too soon since industry is not really ready. Nevertheless, I think it is prudent to plan for it to happen. For example, try buying Altera PLDs. They seem to be readily available in lead but not available in the lead free versions (of course, Altera claims they have both). Part of this situation is caused because everyone (distributors, manufacturers, etc) wants to get rid of their non RoHs inventory. It's hardest on those of us on the end of the chain, since we have the least amount of time to transition.

I think one of the biggest problems will be for products that have relatively long lives and small volume. I have already seen parts that were discontinued just because the mfr didn't want to change to a lead free process. How many designs will have to be completely redone, just to deal with a part that has been obsoleted prematurely. Even if you could buy enough existing material, you still couldn't ship the existing design because there it will never be a RoHS compliant part.

I would bet that this whole RoHS (just the lead part) is going to cost many billions of dollars, with very little improvement overall in the environment. The amount of lead in a typical pcb is very small compared to car batteries, old CRTs, etc.

Sorry for the rant, I'm sure most of you have heard it before (probably coming out of your own mouth).

--
Al Clark
Danville Signal Processing, Inc.
 Click to see the full signature
Reply to
Al Clark

That's the bottom line. I think you can mix component types, but, even if you had RoHS-only, your statement holds. The whole RoHS thing is a disaster waiting to happen, simply because of the way it has been approached. But...what do I know?

I've had conversations with people from various companies across markets who have told me that their whole R&D budget for a year would be consumed if they decided to re-design every product in their product line to meet RoHS. Most will discontinue some products and retool a few and simply make others not available to the EU.

I think you are right, mass-market producers (cell phones, PC's, etc) probably got it together 'cause they are used to very short product cycles anyway. An associate of mine visited a phone manufacturer at the Consumer Electronics Show and asked them when they were going to fix a bug on one of their fairly new high end phones. The answer was to get the new model that just came out.

To go back to the topic of the thread, the gravest concern is that of mid to long term reliability of RoHS or mix-technology assemblies. This whole mess could actually result in MORE electronic trash being produced until metalurgy/chemestry/whatever goes through the required process of "natural selection".

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

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

Reply to
Martin

Martin schrieb:

I am not so sure about this. There are people who are doing lead free for decades now. For example in cases where you can not tolerate the alpha particles emitted by the lead. Or in cases where your electronic is inside a strong magnetic field. (High Energy Physics)

Kolja Sulimma

Reply to
Kolja Sulimma

In its naturally abundant form, lead is stable. It does not emit alpha (or any other) particles...

Can you explain how and why lead behaves differently in strong magnetic fields than the ROHS materials?

This whole ROHS thing is such an idiotic thing to do that it is really frightening how easy it was to drag the whole industry into it...

"Only two things are infinite - the universe and human stupidity, and I'm not sure about the former." A. Einstein

Dimiter

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Reply to
dp

Yeah, but only 1.4% of naturally occuring lead is not radiogenic. The rest comes from decay of thorium, actinium and uranium. Some of those radioactive elements are likely to mixed in with your lead. Cheers, Syms.

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Reply to
Symon

Radiogenic and stable - non-radioactive.

This is what radiogenic means; the result (in this case) being stable isotopes.

Ummm, what? Any figures? Did you ever try to add up the percentages of Pb, Sn and other listed materials at the label of some soldering wire?

Such nonsense - like the entire multi-billion euro ROHS exercise (we have yet to see into whose pockets the billions will flow).

Dimiter (over and out...)

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Reply to
dp

Dimiter, I'll try again. ;-) Production of Solder and Flux with Low Radioactivity

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Quote:- "The lead in solder typically contains trace amounts of U238, Th 232 and K40."

I agree the RoHS is nonsense. However, Kolja is correct that putting lead in solder makes it slightly radioactive. Not because of the lead; because of the contaminants. The contaminants are present as most lead is radiogenic.

Cheers, Syms.

p.s. Here's another link!

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Reply to
Symon

All,

The presence of the U238 to Pb206 chain in lead is well known.

Just go back a few years to our alpha particle contamination issue!

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The solder bumps were roughly 50 counts per hour (alpha emission).

That led to one soft error in 80 days on a 2V6000 (roughly 1200 solder bumps).

Believe me, replacing every part that had the contamination was not something Xilinx would ever like to do ever again!

It had just one bright side: it made everyone aware of the issue, and also made them aware of cosmic ray induced SEUs. So all the work we had done to improve our hardness to upsets began to be noticed...

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Now an alpha is stopped by a piece of paper, so only flip chip parts, with 'solder' bumps, were affected (in our product line).

The solution is purified lead, which is known as ultra-low alpha emitting, which comes in at less than 0.01 counts per hour. Even lead which is completely pure will be "activated" by errant cosmic rays, and will eventually start emitting alphas again as some lead transmutes to polonoium, thorium, etc.

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So, is lead stable? Maybe 1500 meters below ground, or at the bottom of the ocean (like IBM buying old ship's ballast lead for their packages after they first encountered the issue). But once you have it at sea level (or higher), alphas begin to happen again.

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As well there are isotopes which have billion year, and hundreds of thousands of year half life which can not be separated adequately, so when these finally break down, you are left with the series that now emits alphas every few days/weeks/months again...

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'Lead free' just means you didn't intentionally put any lead into the mix, but with leaded fuels still used in parts of the world, turns out that even organic materials have lead in them! And they emit alphas. That makes packaging SRAM chips a real pain (just go ask Cypress) as just about anything you use as a binder in eopoxy for packaging emits some low level of alphas!

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And, Chernobyl didn't help. Nor does bessemer steel processing (which concentrates atmospheric radioactive materials, and binds them into steel). Nor the processing of scrap that accidentially contaminates tons of material with medical radiological chemical wastes.

If you haven't been bit by alphas (yet), then you should go make sure you will not be!

If you are buying ASIC's, well you better go make sure your supplier knows what they are doing! An alpha problem there will drive you nuts.

IBM has been bit, HP has, ... and Xilinx has (we are the some of the few who at least admitted it, faced it head on, and 'solved it' for our customers!)

RoHS does nothing whatsoever for the alpha problem. You will need to buy low alpha, or ultra low alpha RoHS compliant solder pastes, balls, etc. if that is part of your business!

And you will need to test for it, monitor manufacturing processes, use independent work stations and tools to prevent cross contamination ....

So much fun.

Aust> Dimiter,

Reply to
Austin Lesea

Austin,

Well I was perceiving that as low activity. It is certainly interesting to know it can be too much in this area. But at the tiny geometries today, I should have guessed it was.

Thanks for the posting!

That was my main point, lead or not activity problems would be the same, it appears they are hard rather than non-existant in this busyness (as I naively thought). And the point which wakes the beast in me is the total uselessness of that RoHS nonsense, I wish we could do something about it ....

Thanks again,

Dimiter

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Reply to
dp

Dimiter,

As for "does RoHs make my life any safer applied to electronics?" I would have to agree with you: it does not.

There is absolutely no reason to go through this nonsense when automotive lead acid car batteries are thrown away by the roadside and in landfills every day...

I would say clean up the major polluters first, and then go after the next tier. To go after electronics, and electronics assemblies when they conrtibute practically no lead to the environment is just silly.

I can understand not using lead in paint for homes! Or no lead water pipes!

But is this a case of over zealousness?

How about requiring a non-polluting lithium or nickel hydride battery to start the cars, first? Maybe we should go back to a hand crank (with a super capacitor/generator)?

Talk about removing 99.99% of the lead from our environment!

Austin

Reply to
Austin Lesea

My dad told me that back in the days when a hand crank was used to start a car, that the crank could break the driver's arm or wrist if the engine back-fired. So perhaps the solution is to use a car sized version of the generator in that flashlight that's advertised on TV that you shake before turn on the flashlight ;)

-Dave Pollum

Reply to
Dave Pollum

"Dave Pollum" wrote in news: snipped-for-privacy@g47g2000cwa.googlegroups.com:

Just imagine if the billions of dollars being spent on converting electronics to lead free could have been spent on something that would actually have an impact on improving the environment.

Just a simple, back of the envelope calculation would have shown that this whole initiative is crazy.

--
Al Clark
Danville Signal Processing, Inc.
 Click to see the full signature
Reply to
Al Clark

I would say it only looks crazy. Those politicians who have promoted this just cannot be that stupid (although if really caught they will claim exactly that). Nobody is that stupid. I do not know what this is about, but it obviously is not what they claim it is. Perhaps it is just about the money. Perhaps it is a well thought intelligence plan (CIA, KGB, you name it) plan to ruin the European electronics industry (which is not that much alive anyway). Perhaps something I cannot think of now, can be anyones guess. Of course, your original assumption of plain crazyness/stupidity cannot be ruled out, either....

Dimiter

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Reply to
dp

I think you're underestimating the 'ministers' in the European 'parliament'. It's supposed to be the biggest gravy train going, the auditors have refused to sign the accounts for the last few years!

Still it's only our (anyone who lives in the EU) money that's paying for the whole debacle.

Nial (not at all cynical).

Reply to
Nial Stewart

I think there are enough escape clauses in the RoHS, that you do not have to terminate and dump a product line, due to one non complying part. If you can prove that there IS no lead free alternative (yet), ( and that you are diligent in using lead Free, where avaialable) then that's one path.

Another is that a single part, in a Lead-free flow, is unlikely to trigger lead threshold alarms. Product reliability is a different question....

-jg

Reply to
Jim Granville

dp wrote: >

Austin Lesea wrote: > There is absolutely no reason to go through this nonsense when > automotive lead acid car batteries are thrown away by the roadside and > in landfills every day...

Al Clark wrote: > Just imagine if the billions of dollars being spent on converting > electronics to lead free could have been spent on something that would > actually have an impact on improving the environment. >

First of all: ROHS is not only about Lead! It?s also about mercury, cadmium, hexavalent chromium, PBB or PBDE, etc.

It's amazing that there are still people saying that such substances may just be dumped permanently in the environment that should be the environment for the next million years of civilization.

There is done amazingly much research of the effect to humans of these kinds of substances in the environment. Read the background stories of RoHS and WEEE and you probably finally will understand it all. And yes there is much more to do, but this is a very good start.

The EU was late already with these kind of regulations. Japan was smarter already for years. Lucky enough China is the first big one to follow. It's a shame that US, far the largest polluter in the world, still hasn't regulations in this area (the only serious exception is California).

Roel

Reply to
Roel

It's amazing anyone thinks civilization would last a million years.

Reply to
John_H

Lead, mercury, and cadmium all came from the environment. We didn't make them out of something else.

It obviously makes sense to regulate the use and disposal of hazardous substances. It doesn't make sense for that regulation to be a blanket ban on certain uses of them, without regard to how those uses actually affect the environment.

Anyone worrying about the next million years of civilization is crazy, or perhaps ignorant. The rate of technological change is such that we can't predict things five years out, much less a million. That doesn't mean that we shouldn't worry about things that might have negative affects past five years, but it means that it's much more important to worry about the next 25 years or the next 100 years than the next million.

The cost of eliminating lead in paint, plumbing, and gasoline was relatively moderate, and had huge benefits. The cost of eliminating it from all electronics is enormous, and has questionable benefits, slim at best.

Reply to
Eric Smith

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